WorldWideScience

Sample records for arid southwestern united

  1. Algae from the arid southwestern United States: an annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, W.H.; Gaines, S.R.

    1983-06-01

    Desert algae are attractive biomass producers for capturing solar energy through photosynthesis of organic matter. They are probably capable of higher yields and efficiencies of light utilization than higher plants, and are already adapted to extremes of sunlight intensity, salinity and temperature such as are found in the desert. This report consists of an annotated bibliography of the literature on algae from the arid southwestern United States. It was prepared in anticipation of efforts to isolate desert algae and study their yields in the laboratory. These steps are necessary prior to setting up outdoor algal culture ponds. Desert areas are attractive for such applications because land, sunlight, and, to some extent, water resources are abundant there. References are sorted by state.

  2. Ground-Water Recharge in the Arid and Semiarid Southwestern United States

    Science.gov (United States)

    Stonestrom, David A.; Constantz, Jim; Ferre, Ty P.A.; Leake, Stanley A.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly, but irregularly, control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of naturally occurring multidecadal droughts unlike any in the modern instrumental record. Any anthropogenically induced climate change will likely reduce ground-water recharge through diminished snowpack at higher elevations. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Current land-use modifications influence ground-water recharge through vegetation, irrigation, and impermeable area. High mountain ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge areas

  3. Ground-Water Recharge in the Arid and Semiarid Southwestern United States - Climatic and Geologic Framework

    Science.gov (United States)

    Stonestrom, David A.; Harrill, James R.

    2007-01-01

    Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Ni?o and Pacific Decadal Oscillations strongly but irregularly control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of multidecadal droughts unlike any in the modern instrumental record. Anthropogenically induced climate change likely will reduce ground-water recharge through diminished snowpack at higher elevations, and perhaps through increased drought. Future changes in El Ni?o and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Land-use modifications influence ground-water recharge directly through vegetation, irrigation, and impermeable area, and indirectly through climate change. High ranges bounding the study area?the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east?provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive

  4. Using remotely sensed indices of primary productivity to evaluate large mammal abundance and movement in the arid Southwestern United States

    Science.gov (United States)

    Stoner, D.; Edwards, T.; Sexton, J. O.; Nagol, J.; Sims, A.; Ironside, K.; Choate, D.; Longshore, K.; Anand, A.; Mattson, D.

    2013-12-01

    Southwestern ecoregions are marked by topographic and climatic variability, which facilitates the coexistence of large herbivores exploiting different dietary niches. Mountain ungulates buffer this variability through physiological and behavioral adaptations such as fat accumulation and seasonal migrations. However, projected climatic shifts imply changes in vegetation biomass and phenology, and therefore mammalian distributions. Here we evaluate how the distribution of primary productivity and phenological rhythms influence abundance and seasonal movements of three widely distributed ungulate species and their principal predator. We used spatio-temporal patterns in the Normalized Difference Vegetation Index (NDVI) derived from MODerate-resolution Imaging Spectrometer (MODIS) measurements at 250-m, daily resolution to explain spatial variability in the abundance of mule deer, elk, and bighorn sheep. Ungulate population response to NDVI was assessed using annual survey data collected by state wildlife agencies with jurisdiction on and around the Colorado Plateau ecoregion. We used NDVI-ungulate relationships to evaluate the spatial requirements and potential densities of cougars; a predator whose diet, density, and distribution is closely tied to these species. Cougar location data were combined from nine radio-telemetry studies conducted over a range of climatic conditions. Focal ungulates demonstrated differing responses to patterns in NDVI. Mule deer abundance corresponded to the timing of green-up (late spring), elk abundance correlated best with peak green biomass (July-Aug), and bighorn showed no relationship to NDVI. Seasonal movements also differed, with deer migrating between distinct summer and winter ranges; bighorn residing on annual ranges, and elk demonstrating a mixed pattern of residency and migration. Cougar movements did not correspond to phenology per se, but home range size and diet diversity varied inversely with NDVI. Projected shifts in the

  5. Point sources of emerging contaminants along the Colorado River Basin: source water for the arid Southwestern United States.

    Science.gov (United States)

    Jones-Lepp, Tammy L; Sanchez, Charles; Alvarez, David A; Wilson, Doyle C; Taniguchi-Fu, Randi-Laurant

    2012-07-15

    Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into empty SPEs and eluted with methanol. All extracts were prepared for, and analyzed by, liquid chromatography-electrospray-ion trap mass spectrometry (LC-ESI-ITMS). Log D(OW) values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the yeast estrogen screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicity response. In the grab samples, azithromycin (an antibiotic) was detected in all but one urban waste stream, with concentrations ranging from 30ng/L to 2800ng/L. Concentration levels of azithromycin, methamphetamine and pseudoephedrine showed temporal variation from the Tucson WWTP. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10ng/L), but most were below detection limits. PMID:22684090

  6. Extended megadroughts in the southwestern United States during Pleistocene interglacials

    NARCIS (Netherlands)

    Fawcett, P.J.; Werne, J.P.; Anderson, R.S.; Heikoop, J.M.; Brown, E.T.; Berke, M.A.; Smith, S.J.; Goff, F.; Donohoo-Hurley, L.; Cisneros-Dozal, L.M.; Schouten, S.; Sinninghe Damsté, J.S.; Huang, Y.S.; Toney, J.; Fessenden, J.; WoldeGabriel, G.; Atudorei, V.; Geissman, J.W.; Allen, C.D.

    2011-01-01

    The potential for increased drought frequency and severity linked to anthropogenic climate change in the semi-arid regions of the southwestern United States (US) is a serious concern(1). Multi-year droughts during the instrumental period(2) and decadal-length droughts of the past two millennia(1,3)

  7. Drought in Southwestern United States

    Science.gov (United States)

    2007-01-01

    The southwestern United States pined for water in late March and early April 2007. This image is based on data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite from March 22 through April 6, 2007, and it shows the Normalized Difference Vegetation Index, or NDVI, for the period. In this NDVI color scale, green indicates areas of healthier-than-usual vegetation, and only small patches of green appear in this image, near the California-Nevada border and in Utah. Larger areas of below-normal vegetation are more common, especially throughout California. Pale yellow indicates areas with generally average vegetation. Gray areas appear where no data were available, likely due to persistent clouds or snow cover. According to the April 10, 2007, update from the U.S. Drought Monitor, most of the southwestern United Sates, including Utah, Nevada, California, and Arizona, experienced moderate to extreme drought. The hardest hit areas were southeastern California and southwestern Arizona. Writing for the Drought Monitor, David Miskus of the Joint Agricultural Weather Facility reported that March 2007 had been unusually dry for the southwestern United States. While California's and Utah's reservoir storage was only slightly below normal, reservoir storage was well below normal for New Mexico and Arizona. In early April, an international research team published an online paper in Science noting that droughts could become more common for the southwestern United States and northern Mexico, as these areas were already showing signs of drying. Relying on the same computer models used in the Intergovernmental Panel on Climate Change (IPCC) report released in early 2007, the researchers who published in Science concluded that global warming could make droughts more common, not just in the American Southwest, but also in semiarid regions of southern Europe, Mediterranean northern Africa, and the Middle East.

  8. A Reservoir of Natural Perchlorate in Unsaturated Zones of Arid and Semi-Arid Regions, Southwestern USA

    Science.gov (United States)

    Rao, B. A.; Stonestrom, D. A.; Anderson, T. A.; Orris, G. J.; Rajagapolan, S.; Sandvig, R. M.; Scanlon, B. R.; Walvoord, M. A.; Jackson, W.

    2006-12-01

    Natural perchlorate (ClO4-) is generally present in unsaturated zones of steppe-to-desert regions of the arid and semi-arid southwestern United States. The perchlorate is associated with atmospherically deposited chloride that has accumulated throughout the Holocene. To assess this natural reservoir, we analyzed unsaturated-zone profiles from ten sites across Nevada, New Mexico, Texas, and Utah for perchlorate and other anions. The sampled sites represent a wide range of precipitation (0.1 0.5 m yr-1), dominant vegetation, soil type, underlying geology, and include five distinct ecological regions: Chihuahuan, Mojave, and southern Great Basin deserts; Arizona-New Mexico semi-desert; and Texas High Plains dry steppe. Concentrations of perchlorate correlated closely with chloride and bromide. The perchlorate reservoir (up to 1 kg ha-1) is sufficiently large to impact groundwater when natural recharge during pluvial periods or induced recharge after conversion to agriculture flushes accumulated salts from the unsaturated zone. This little explored source can explain perchlorate in milk and other agricultural products far from anthropogenic contamination, and should be considered when evaluating overall exposure risk.

  9. Spatial distribution and comparison of aridity indices in Extremadura, southwestern Spain

    Science.gov (United States)

    Moral, Francisco J.; Rebollo, Francisco J.; Paniagua, Luis L.; García-Martín, Abelardo; Honorio, Fulgencio

    2015-09-01

    In semi-arid lands with warm climates, aridity is a real hazard, with the threat of desertification because of greater precipitation variability and prolonged droughts. Aridity indices can be used to identify areas prone to desertification. The present study aimed to analyse the spatial distribution of aridity in Extremadura, southwestern Spain, using three indices: the De Martonne aridity index (I DM), the Pinna combinative index (I P), and the Food and Agriculture Organization (FAO) aridity index (I F). Temperature, precipitation, and evapotranspiration data from 90 weather stations located throughout Extremadura and 27 along boundaries with at least 30-year length (within the 1980-2011 period) were used to compute each index at each station. The statistical properties of each aridity index were assessed, and later, they were mapped by means of an integrated geographic information system (GIS) and a multivariate geostatistical (regression-kriging) algorithm in which exhaustive secondary information on elevation was incorporated. Annual and seasonal I DM and I F, and annual I P-kriged maps were generated. According to annual I DM, the semi-arid and Mediterranean conditions are predominant in the region, covering about 70 % of the territory, while about 94 % of the areas are classified as dry and semi-dry Mediterranean based on annual I P and about 86 % are classified as semi-arid and dry categories based on annual I F. The most vulnerable to aridity are the natural regions located to the west, the south, and the southeast of Extremadura, especially during summer, when arid conditions are found across the region. Although the three aridity indices were highly correlated, displaying similar spatial patterns, I DM was preferred because it can better discriminate different climate conditions in Extremadura.

  10. Documentation of Arid Land Soilscapes in Southwestern Europe

    Science.gov (United States)

    José Ibáñez, Juan; Pérez-Gómez, Rufino; Oyonarte, Cecilio; Brevik, Eric C.

    2016-04-01

    There have been no studies to date that have proven the existence of soil assemblages typical of arid lands in Europe. This study was carried out in Almería province, a representative territory of the SE part of the Iberian Peninsula which is the driest part of Europe, to determine if soils characteristic of arid lands were present. The study made use of mathematical tools previously developed in biodiversity and pedodiversity analysis, such as richness, entropy indices, abundance distribution models, diversity-area relationships and nested subset analysis to analyse the spatial distribution of soils. The study demonstrated that the soil types or pedotaxa are typical of mountainous arid lands. Shallow and weakly developed soils (e.g. Leptosols, Regosols, Arenosols), Calcisols, Gypsisols and Solonchaks cover most of the study area, and pedodiversity analysis demonstrates that the pedotaxa spatial patterns follow the same regularities as in other areas, environments and scales. In view of the fact that the class of landscapes identified in this study are unique in Europe, the Tarbernas desert and other arid lands sites of the study area merit preservation as part of the European geological, geomorphological, and pedological heritage.

  11. Spatial analysis of the annual and seasonal aridity trends in Extremadura, southwestern Spain

    Science.gov (United States)

    Moral, Francisco J.; Paniagua, Luis L.; Rebollo, Francisco J.; García-Martín, Abelardo

    2016-09-01

    The knowledge of drought (or wetness) conditions is necessary not only for a rational use of water resources but also for explaining landscape and ecology characteristics. An increase in aridity in many areas of the world is expected because of climate change (global warming). With the aim of analysing annual and seasonal aridity trends in Extremadura, southwestern Spain, climate data from 81 locations within the 1951-2010 period were used. After computing the De Martonne aridity index at each location, a geographic information system (GIS) and multivariate geostatistics (regression kriging) were utilised to map this index throughout the region. Later, temporal trends were analysed using the Mann-Kendall test, and the Sen's estimator was utilised to estimate the magnitude of trends. Maps of aridity trends were generated by ordinary kriging algorithm, providing a visualisation of detected annual and seasonal tendencies. An increase in aridity, as the De Martonne aridity index decreased, was apparent during the study period, mainly in the more humid locations of the north of the region. An increase of the seasonal De Martonne aridity index was also found, but it was only statistically significant in some locations in spring and summer, with the highest decreasing rate in the north of Extremadura. Change year detection was achieved using cumulative sum graphs, obtaining that firstly the change point occurred in spring, in the mid-1970s, later in the annual period in the late 1970s and finally in summer at the end of the 1980s.

  12. Precipitation Intensity Effects on Groundwater Recharge in the Southwestern United States

    Directory of Open Access Journals (Sweden)

    Brian F. Thomas

    2016-03-01

    Full Text Available Episodic recharge as a result of infrequent, high intensity precipitation events comprises the bulk of groundwater recharge in arid environments. Climate change and shifts in precipitation intensity will affect groundwater continuity, thus altering groundwater recharge. This study aims to identify changes in the ratio of groundwater recharge and precipitation, the R:P ratio, in the arid southwestern United States to characterize observed changes in groundwater recharge attributed to variations in precipitation intensity. Our precipitation metric, precipitation intensity magnification, was used to investigate the relationship between the R:P ratio and precipitation intensity. Our analysis identified significant changes in the R:P ratio concurrent with decreases in precipitation intensity. The results illustrate the importance of precipitation intensity in relation to groundwater recharge in arid regions and provide further insights for groundwater management in nonrenewable groundwater systems and in a changing climate.

  13. Basin-scale recharge in the Southwestern United States

    Science.gov (United States)

    Hogan, J. F.; Duffy, C.; Eastoe, C.; Ferre, T. P. A.; Goodrich, D.; Hendrickx, J.; Hibbs, B.; Phillips, F.; Small, E.; Wilson, J.

    2003-04-01

    The major domestic water source in the arid southwestern United States is groundwater from alluvial basin aquifers. Accurate estimates of basin-scale groundwater recharge rates are a critical need for developing sustainable or "safe yield" groundwater pumping. Basin-scale recharge rates are typically estimated using inverse hydrologic modeling or geochemical tracers (e.g. chloride mass balance). These methods, while useful, have a high level of uncertainty and provide no information about the mechanisms of groundwater recharge. SAHRA - an NSF Science and Technology Center focused on the Sustainability of semi-Arid Hydrology and Riparian Areas - has developed an integrated research plan to address this problem. Our approach is two-fold. First we are investigating the "input" components that comprise basin-scale recharge: basin floor recharge, alluvial channel recharge, mountain front recharge, and mountain block recharge. Each component has unique spatial and temporal scales and thus requires distinct methods. Our research is aimed at understanding the factors (e.g. vegetation type, bedrock lithology, soil structure) that control recharge rates in each of these locations. With such an understanding one could then scale from point measurements to the basin-scale using remote sensing data. Our second approach is to employ isotopic tracers to determine water sources, groundwater ages and residence times of the groundwater and surface water "outputs"; these values can then be used to better calibrate recharge rates in groundwater models. By focusing our studies on two basins, the San Pedro River Basin in Arizona and the Rio Grande in New Mexico, we hope to develop a better understanding of the importance of different recharge pathways for basin-scale recharge and which methods are best suited for estimating basin-scale recharge.

  14. Long-term aridity changes in the western United States.

    Science.gov (United States)

    Cook, Edward R; Woodhouse, Connie A; Eakin, C Mark; Meko, David M; Stahle, David W

    2004-11-01

    The western United States is experiencing a severe multiyear drought that is unprecedented in some hydroclimatic records. Using gridded drought reconstructions that cover most of the western United States over the past 1200 years, we show that this drought pales in comparison to an earlier period of elevated aridity and epic drought in AD 900 to 1300, an interval broadly consistent with the Medieval Warm Period. If elevated aridity in the western United States is a natural response to climate warming, then any trend toward warmer temperatures in the future could lead to a serious long-term increase in aridity over western North America.

  15. Increased aridity in southwestern Africa during the last-interglacial warmest periods

    Directory of Open Access Journals (Sweden)

    D. H. Urrego

    2013-07-01

    Full Text Available We use pollen analysis of marine sediments from core MD96-2098 to produce a paleoenvironmental record spanning from 190 to 24.7 ka (thousand years before present from southern Africa. Our interpretations of the pollen record are supported by an analysis of present day pollen spectra for the region. We apply canonical correspondence analysis (CCA and detrended correspondence analysis (DCA on pollen spectra from terrestrial surface samples to investigate pollen spectra-climate relationships. We identify pollen taxa that are suitable indicators for the different South African biomes, and assess in detail the distribution and potential interpretation of Poaceae pollen signals in marine sediments along the southwestern African coast. The pollen record from MD96-2098 documented major increases of Poaceae pollen percentages, that are interpreted as expansions of semi-arid southwestern African biomes (i.e. the Nama-Karoo and fine-leaved savannas during Marine Isotope Stage (MIS 5e, 5c and 5a substages. These expansions coincided with minima in precession and global ice volume. They likely resulted from a combination of reduced Benguela upwelling; expanded subtropical high pressure and reduced austral-summer precipitation due to a northward shift of the Intertropical Convergence Zone (ITCZ; and a southern displacement of the westerlies and decreased austral-winter precipitation. During glacial isotopic stages MIS 6, 4 and 3, Fynbos expanded at the expense of semi-arid biomes. Stage and substage transitions were characterised by small but rapid increases in Podocarpus indicating a humidity increase. Increased millennial-scale variability in the vegetation and climate of southern Africa is also suggested for the last 100 ka.

  16. A Review of Applicability and Effectiveness of Low Impact Development/Green Infrastructure Practices in Arid/Semi-Arid United States

    Directory of Open Access Journals (Sweden)

    Yan Jiang

    2015-06-01

    Full Text Available Urbanized areas of the southwestern/western United States are among the fastest growing in the nation and face multiple water resource challenges. Low impact development (LID/green infrastructure (GI practices are increasingly popular technologies for managing stormwater; however, LID is often not as common in the southwest/west due to the lack of regulatory and/or economic drivers. There is also a lack of performance evaluation of these practices, particularly at the field scale. This study focused on investigating the hydrologic and pollutant removal performance of field-scale LID/GI systems in arid/semi-arid climates. Nine typical practices were reviewed: rainwater harvest system, detention pond, retention pond, bioretention, media filter, porous pavement, vegetated swale/buffer/strip, green roof, and infiltration trench, as well as integrated LIDs. We evaluate these practices by a cost-effectiveness analysis and also recommend best practices for the arid/semi-arid area. The analysis provides data support and insights for future implementation of LID/GI in the southwest/west.

  17. Trichinella infection in wildlife of the southwestern United States.

    Science.gov (United States)

    Pozio, E; Pence, D B; La Rosa, G; Casulli, A; Henke, S E

    2001-10-01

    Several potential mammalian reservoirs of sylvatic species of Trichinella were examined from Texas, New Mexico, and Arizona. During 1998-99, tongues were collected from a black bear (Ursus americanus) in Arizona; from 9 black bears, a coyote (Canis latrans), and a mountain lion (Felis concolor) in New Mexico; and from 154 coyotes, 32 raccoons (Procyon lotor), 13 opossums (Didelphis marsupialis), 4 ocelots (Leopardus pardalis), 3 bobcats (Lynx rufus), and 5 feral hogs (Sus scrofa) in southern Texas. Larvae of Trichinella murrelli were identified by a multiple-polymerase chain reaction analysis in 1 black bear (11.1%) from New Mexico and in 7 coyotes (4.5%) of Texas, whereas Trichinella spiralis larvae were detected in the black bear of Arizona. This is the first report of Trichinella infection in wildlife of New Mexico and Texas and extends the distribution of T. murrelli into the southwestern United States near the border of Mexico. PMID:11695403

  18. LAND SUITABILITY SCENARIOS FOR ARID COASTAL PLAINS USING GIS MODELING: SOUTHWESTERN SINAI COASTAL PLAIN, EGYPT

    OpenAIRE

    Ahmed Mohamed Wahid; Marguerite Madden; Fikry Khalaf; Ibtehal Fathy

    2009-01-01

    Site selection analysis was carried out to find the best suitable lands for development activities in an example of promising coastal plains, southwestern Sinai, Egypt. Two GIS models were developed to represent two scenarios of land use suitability in the study area using GIS Multi Criteria Analysis Modeling. The factors contributed in the analysis are the Topography, Land cover, Existing Land use, Flash flood index, Drainage lines and Water points. The first scenario was to classify the are...

  19. Modeling the distributed effects of forest thinning on the long-term water balance and streamflow extremes for a semi-arid basin in the southwestern US

    OpenAIRE

    Moreno, Hernan A.; Gupta, Hoshin V.; Dave D. White; Sampson, David A.

    2016-01-01

    To achieve water resource sustainability in the water-limited southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basinwise streamflows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along...

  20. LAND SUITABILITY SCENARIOS FOR ARID COASTAL PLAINS USING GIS MODELING: SOUTHWESTERN SINAI COASTAL PLAIN, EGYPT

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Wahid

    2009-12-01

    Full Text Available Site selection analysis was carried out to find the best suitable lands for development activities in an example of promising coastal plains, southwestern Sinai, Egypt. Two GIS models were developed to represent two scenarios of land use suitability in the study area using GIS Multi Criteria Analysis Modeling. The factors contributed in the analysis are the Topography, Land cover, Existing Land use, Flash flood index, Drainage lines and Water points. The first scenario was to classify the area according to various gradual ranges of suitability. According to this scenario, the area is classified into five classes of suitability. The percentage of suitability values are 51.16, 6.13, 22.32, 18.49 and 1.89% for unsuitable, least suitable, low suitable, suitable and high suitable, respectively. The second scenario is developed for a particular kind of land use planning; tourism and recreation projects. The suitability map of this scenario was classified into five values. Unsuitable areas represent 51.18% of the study area, least suitable 16.67%, low suitable 22.85%, suitable 8.61%, and high suitable 0.68%. The best area for locating development projects is the area surrounding El-Tor City and close to the coast. This area could be an urban extension of El-Tor City with more economical and environmental management.

  1. Arid land irrigation in the United States Pacific Northwest for 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of arid land irrigation in the Pacific Northwest region of the United...

  2. Gravity Monitoring of Ground-Water Storage Change in the Southwestern United States

    Science.gov (United States)

    Winester, D.; Pool, D. R.; Schmerge, D. L.; Hoffmann, J. P.; Keller, G. R.

    2004-12-01

    Repeat measurements of absolute gravity have been made since 1998 to estimate changes in ground-water mass as part of ground-water budget estimates in arid and semiarid regions of the Southwestern United States. The absolute acceleration of gravity is measured twice each year at 16 stations to an accuracy of about plus or minus 2 microGal, or about 5 cm of water. Observations are normally done for the purpose of providing gravity control for relative gravity surveys of networks of stations across wider areas. Other data incorporated into the ground-water budget estimates include precipitation, water levels, moisture content in the unsaturated zone, surface water runoff, and ellipsoid heights using the Global Positioning System (GPS). Gravity and water-level changes are correlated for stations measured in the Basin and Range Physiographic Province near Tucson, Phoenix, Casa Grande, and Sierra Vista, Arizona. Decreasing gravity and water levels in the Tucson area since the summer of 1998 are likely related to predominant drought conditions and decreases in ground-water storage following above average winter precipitation and recharge during the El Nino of 1998. Increases in gravity at stations in the upper and middle Verde Valley Watershed in central Arizona since the fall of 2000 do not correlate well with declining streamflows and water levels and may be caused by temporary increases in soil moisture following wet winters. There have been no significant observed gravity changes at two stations in the El Paso, Texas, area since the initial observations during the summer of 2003, even though ground-water pumping in the area has been heavy.

  3. 77 FR 30437 - Proposed Amendment of Air Traffic Service Routes; Southwestern United States

    Science.gov (United States)

    2012-05-23

    ...; Southwestern United States as published in the Federal Register of April 23, 2010 (77 FR 24156) FR Doc. 2012... (77 FR 24156). The description of V-16 in the NPRM did not reflect a previous amendment of the route that was published on September 19, 2011 (76 FR 57902). The incorrect part of the V-16 description...

  4. Field measurement and analysis of climatic factors affecting dune mobility near Grand Falls on the Navajo Nation, southwestern United States

    Science.gov (United States)

    Bogle, Rian C.; Redsteer, Margaret Hiza; Vogel, John M.

    2015-01-01

    Aeolian sand covers extensive areas of the Navajo Nation in the southwestern United States. Much of this sand is currently stabilized by vegetation, although many drier parts of these Native lands also have active and partly active dunes. Current prolonged drought conditions that started in the mid-1990s are producing significant changes in dune mobility. Reactivation of regional aeolian deposits due to drought or increasing aridity from rising temperatures resulting from climate change could have serious consequences for human and animal populations, agriculture, grazing, and infrastructure. To understand and document the current and future potential for mobility, seasonally repeated surveys were used to track the location of multiple active barchan dunes. By utilizing Real-Time Kinematic GPS field surveys and simultaneously collecting in-situ meteorological data, it is possible to examine climatic parameters and seasonal variations that affect dune mobility and their relative influences. Through analysis of the recorded data, we examined the fit of various climate parameters, and demonstrate that under the current prolonged drought, wind power is the dominant factor controlling dune mobility.

  5. Conceptual understanding and groundwater quality of selected basin-fill aquifers in the Southwestern United States

    Science.gov (United States)

    Thiros, Susan A.; Bexfield, Laura M.; Anning, David W.; Huntington, Jena M.

    2010-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey has been conducting a regional analysis of water quality in the principal aquifer systems in the southwestern United States (hereinafter, 'Southwest') since 2005. Part of the NAWQA Program, the objective of the Southwest Principal Aquifers (SWPA) study is to develop a better understanding of water quality in basin-fill aquifers in the region by synthesizing information from case studies of 15 basins into a common set of important natural and human-related factors found to affect groundwater quality. The synthesis consists of three major components: 1. Summary of current knowledge about the groundwater systems, and the status of, changes in, and influential factors affecting quality of groundwater in basin-fill aquifers in 15 basins previously studied by NAWQA (this report). 2. Development of a conceptual model of the primary natural and human-related factors commonly affecting groundwater quality, thereby building a regional understanding of the susceptibility and vulnerability of basin-fill aquifers to contaminants. 3. Development of statistical models that relate the concentration or occurrence of specific chemical constituents in groundwater to natural and human-related factors linked to the susceptibility and vulnerability of basin-fill aquifers to contamination. Basin-fill aquifers occur in about 200,000 mi2 of the 410,000 mi2 SWPA study area and are the primary source of groundwater supply for cities and agricultural communities. Four of the principal aquifers or aquifer systems of the United States are included in the basin-fill aquifers of the study area: (1) the Basin and Range basin-fill aquifers in California, Nevada, Utah, and Arizona; (2) the Rio Grande aquifer system in New Mexico and Colorado; (3) the California Coastal Basin aquifers; and (4) the Central Valley aquifer system in California. Because of the generally limited availability of surface-water supplies in

  6. Models of Regional Habitat Quality and Connectivity for Pumas (Puma concolor) in the Southwestern United States

    OpenAIRE

    Dickson, Brett G.; Roemer, Gary W.; Mcrae, Brad H.; Jill M. Rundall

    2013-01-01

    The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is of global conservation concern. In the southwestern United States, pumas (Puma concolor) are a well distributed and wide-ranging large carnivore that are sensitive to loss of habitat and to the disruption of pathways that connect their populations. We used an expert-based approach to define and derive variables hypothesized to influence the quality, location, and permeability of habita...

  7. Deserts of the southwestern United States, for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundaries of the deserts of the southwestern United States. Those deserts include the Great Basin, Mojave, Colorado, and Sonoran...

  8. Population Growth, Climate Change and Water Scarcity in the Southwestern United States

    Directory of Open Access Journals (Sweden)

    Amy c. Fuller

    2010-01-01

    Full Text Available Problem statement: In a simple economic model, water scarcity arises as a result of an imbalance between the supply of and demand for water sources. Distribution in this setting is the source of numerous conflicts globally. Approach: Already, the Southwestern United States (US suffers from annual drought and long-standing feud over natural water resources. Results: Population growth in the Southwestern United States along with the continued effects of climate change (natural and anthropogenic predicts a perpetual decline in natural water sources, such as smaller snowpacks, in the coming years. As the increasing number of communities across multiple US states that subsist off of natural water supplies face water shortages with increasing severity, further water conflict will emerge. Such conflicts become especially protracted when the diversion of water from a source of benefit to one community negatively impacts nearby communities of humans and economically vital ecosystems (e.g., marshlands or tributaries. Conclusion/Recommendations: The ensuing politics and health effects of these diversions can be complicated and future water policies both domestically and internationally are lacking. To draw attention to and stimulate discussion around the lacking policy discussion domestically, herein we document existing and emerging consequences of watery scarcity in the Southwestern United States and briefly outline past and potential future policy responses.

  9. Productivity and residual benefits of grain legumes to sorghum under semi-arid conditions in southwestern Zimbabwe

    NARCIS (Netherlands)

    Ncube, B.; Twomlow, S.J.; Wijk, van M.T.; Dimes, J.P.; Giller, K.E.

    2007-01-01

    The productivity and residual benefits of four grain legumes to sorghum (Sorghum bicolor) grown in rotation were measured under semi-arid conditions over three cropping seasons. Two varieties of each of the grain legumes; cowpea (Vigna unguiculata); groundnut (Arachis hypogaea); pigeon pea (Cajanus

  10. Modeling the distributed effects of forest thinning on the long-term water balance and stream flow extremes for a semi-arid basin in the southwestern US

    Directory of Open Access Journals (Sweden)

    H. A. Moreno

    2015-10-01

    Full Text Available To achieve water resources sustainability in the water-limited Southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basin-wise stream flows. In Arizona, the Four Forest Restoration Initiative (4FRI is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed tRIBS model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde–Tonto–Salt (VTS system, which provides much of the water supply for the Phoenix Metropolitan Area. Long-term (20 year simulations indicate that forest removal can trigger significant shifts in the spatio-temporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge, and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum stream flow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snow pack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

  11. Modeling the distributed effects of forest thinning on the long-term water balance and streamflow extremes for a semi-arid basin in the southwestern US

    Science.gov (United States)

    Moreno, Hernan A.; Gupta, Hoshin V.; White, Dave D.; Sampson, David A.

    2016-03-01

    To achieve water resource sustainability in the water-limited southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basinwise streamflows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed triangulated irregular network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde-Tonto-Salt (VTS) system, which provides much of the water supply for the Phoenix metropolitan area. Long-term (20-year) simulations indicate that forest removal can trigger significant shifts in the spatiotemporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south-facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum streamflow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snowpack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

  12. Arid land irrigation in the United States Pacific Northwest for 2001 summarized for NHDPlus v2 catchments

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the area of arid land irrigation in the Pacific Northwest region of the United...

  13. Physical and chemical properties of soils under some wild Pistachio (Pistacia atlantica Desf) canopies in a semi-arid ecosystem, southwestern Iran.

    Science.gov (United States)

    Owliaie, Hamidreza

    2010-05-01

    Pistacia atlantica Desf. is one of the most important wild species in Zagros forests which is of high economical and environmental value. Sustainability of these forests primarily depends on soil quality and water availability. Study the relationships between trees and soil is one of the basic factors in management and planning of forests. Hence, this study was undertaken with the objective of assessing the effect of tree species on soil physical and chemical properties in a semi-arid region (Kohgilouye Province) in the southwestern part of Iran. The experimental design was a factorial 4×2 (4 depths and 2 distances) in a randomized complete block design with six replications. Soil samples (0-20, 20-40, 40-60 and 60-80 cm depth) were taken from beneath the tree crowns and adjacent open areas. Soil samples were analyzed for physical and chemical properties. The results showed that wild pistachio canopy increased mostly organic carbon, hydraulic conductivity, total N, SP, available K+, P (olsen), EC, EDTA extractable Fe2+ and Mn2+, while bulk density, CCE and DTPA extractable Cu2+ were decreased. Pistachio canopy had no significant effect on soil texture, Zn2+ and pH.

  14. Comparison of two approaches for detecting the depth of edge influence on vegetation diversity in the arid valley of southwestern China

    Institute of Scientific and Technical Information of China (English)

    LILi-guang; HEXing-yuan; LIXiu-zhen; WENQing-chun; ZHAOYong-hua

    2005-01-01

    Three types of landscape boundary (forest/pepper field, forest/cabbage field, and forest/grassland) were selected in the arid valley of upper reaches of Minjiang River, southwestern China. On the basis of vegetation diversity, the depth of edge influence (DEI) on different types of landscape boundaries was estimated using principal components analysis (PCA) method and moving split-window techniques (MSWT). The results showed that in the 5 transects, PCA method was able to detect the edge influence depth with 3 transects, while MSWT could explain 4 transects. It is concluded that PCA and MSWT both can be used to detect the depth of edge influence within 50 m from the edge to the interior. Similar conclusions were drawn in the forest of each transect with the two methods, but no similar conclusions were drawn in the pepper field of each transect. Although the two methods have advantages and disadvantages respectively, they are useful tools for characterizing edge dynamics. Comparing the two methods, MSWT is more successful.

  15. Tree Morphologic Plasticity Explains Deviation from Metabolic Scaling Theory in Semi-Arid Conifer Forests, Southwestern USA.

    Science.gov (United States)

    Swetnam, Tyson L; O'Connor, Christopher D; Lynch, Ann M

    2016-01-01

    A significant concern about Metabolic Scaling Theory (MST) in real forests relates to consistent differences between the values of power law scaling exponents of tree primary size measures used to estimate mass and those predicted by MST. Here we consider why observed scaling exponents for diameter and height relationships deviate from MST predictions across three semi-arid conifer forests in relation to: (1) tree condition and physical form, (2) the level of inter-tree competition (e.g. open vs closed stand structure), (3) increasing tree age, and (4) differences in site productivity. Scaling exponent values derived from non-linear least-squares regression for trees in excellent condition (n = 381) were above the MST prediction at the 95% confidence level, while the exponent for trees in good condition were no different than MST (n = 926). Trees that were in fair or poor condition, characterized as diseased, leaning, or sparsely crowned had exponent values below MST predictions (n = 2,058), as did recently dead standing trees (n = 375). Exponent value of the mean-tree model that disregarded tree condition (n = 3,740) was consistent with other studies that reject MST scaling. Ostensibly, as stand density and competition increase trees exhibited greater morphological plasticity whereby the majority had characteristically fair or poor growth forms. Fitting by least-squares regression biases the mean-tree model scaling exponent toward values that are below MST idealized predictions. For 368 trees from Arizona with known establishment dates, increasing age had no significant impact on expected scaling. We further suggest height to diameter ratios below MST relate to vertical truncation caused by limitation in plant water availability. Even with environmentally imposed height limitation, proportionality between height and diameter scaling exponents were consistent with the predictions of MST. PMID:27391084

  16. Quantifying the vulnerability of carbon stocks and fluxes in six semi-arid biomes in the Southwestern US to the severe 2011-2013 drought (Invited)

    Science.gov (United States)

    Litvak, M. E.; Krofcheck, D.; Hilton, T. W.; Fox, A. M.

    2013-12-01

    The magnitude of carbon fluxes through arid and semi-arid ecosystems is considered modest, but integrated over the ~40% of the global land surface covered by these ecosystems, the total carbon stored is almost twice that in temperate forest ecosystems. Climatic extremes are typical in the Southwestern U.S, and the frequency of extreme temperature and precipitation events (both drought and large storms) in this region is predicted to increase in the next century. Understanding how resilient carbon pools and fluxes in these biomes are to climate extremes constitutes a large uncertainty in our ability to understand regional carbon balance. We use a 7 year record (2007-2013) of continuous measurements of net ecosystem exchange of carbon (NEE) and its components (gross primary productivity (GPP) and ecosystem respiration (Re) made over the New Mexico Elevation Gradient (NMEG) network of flux tower sites (desert grassland, creosote shrubland, juniper savanna, piñon-juniper woodland, ponderosa pine and subalpine mixed conifer) to test hypotheses about the biome-specific sensitivity of carbon cycling to both drought and temperature extremes. In particular, we focus on the functional responses in these biomes to the extended drought in this region from 2011-2013, which has triggered extensive mortality in many biomes. We used time series of climatic variables, radiation absorbed by vegetation, sap flux, soil moisture storage, and remotely sensed structural and functional data, including rates of mortality, to compare the biome-specific mechanisms behind these responses. We also produce biome-specific functional response surfaces of productivity and respiration to VPD, temperature and soil water availability. Decreases in annual NEP from the relatively wet year of 2010 to the severe drought year 2011 ranged from 60-165 g C m-2 y-1 across the gradient, due more to decreases in GPP than Re. We observed the greatest sensitivity to both temperature and precipitation extremes in

  17. Models of regional habitat quality and connectivity for pumas (Puma concolor) in the southwestern United States.

    Science.gov (United States)

    Dickson, Brett G; Roemer, Gary W; McRae, Brad H; Rundall, Jill M

    2013-01-01

    The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is of global conservation concern. In the southwestern United States, pumas (Puma concolor) are a well distributed and wide-ranging large carnivore that are sensitive to loss of habitat and to the disruption of pathways that connect their populations. We used an expert-based approach to define and derive variables hypothesized to influence the quality, location, and permeability of habitat for pumas within an area encompassing the entire states of Arizona and New Mexico. Survey results indicated that the presence of woodland and forest cover types, rugged terrain, and canyon bottom and ridgeline topography were expected to be important predictors of both high quality habitat and heightened permeability. As road density, distance to water, or human population density increased, the quality and permeability of habitats were predicted to decline. Using these results, we identified 67 high quality patches across the study area, and applied concepts from electronic circuit theory to estimate regional patterns of connectivity among these patches. Maps of current flow among individual pairs of patches highlighted possible pinch points along two major interstate highways. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected, regardless of patch size. Cumulative current flow was highest in Arizona north of the Colorado River and around Grand Canyon National Park, and in the Sky Islands region owing to the many small habitat patches present. Our outputs present a first approximation of habitat quality and connectivity for dispersing pumas in the southwestern United States. Map results can be used to help target finer-scaled analyses in support of planning efforts concerned with the maintenance of puma metapopulation structure, as well as the protection of landscape features that facilitate the dispersal

  18. Models of regional habitat quality and connectivity for pumas (Puma concolor in the southwestern United States.

    Directory of Open Access Journals (Sweden)

    Brett G Dickson

    Full Text Available The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is of global conservation concern. In the southwestern United States, pumas (Puma concolor are a well distributed and wide-ranging large carnivore that are sensitive to loss of habitat and to the disruption of pathways that connect their populations. We used an expert-based approach to define and derive variables hypothesized to influence the quality, location, and permeability of habitat for pumas within an area encompassing the entire states of Arizona and New Mexico. Survey results indicated that the presence of woodland and forest cover types, rugged terrain, and canyon bottom and ridgeline topography were expected to be important predictors of both high quality habitat and heightened permeability. As road density, distance to water, or human population density increased, the quality and permeability of habitats were predicted to decline. Using these results, we identified 67 high quality patches across the study area, and applied concepts from electronic circuit theory to estimate regional patterns of connectivity among these patches. Maps of current flow among individual pairs of patches highlighted possible pinch points along two major interstate highways. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected, regardless of patch size. Cumulative current flow was highest in Arizona north of the Colorado River and around Grand Canyon National Park, and in the Sky Islands region owing to the many small habitat patches present. Our outputs present a first approximation of habitat quality and connectivity for dispersing pumas in the southwestern United States. Map results can be used to help target finer-scaled analyses in support of planning efforts concerned with the maintenance of puma metapopulation structure, as well as the protection of landscape features that facilitate

  19. Lagrangian particle modeling of air pollution transport in southwestern United States

    Energy Technology Data Exchange (ETDEWEB)

    Uliasz, M. [Warsaw Univ. of Technology (Poland); Stocker, R.A.; Pielke, R.A. [Colorado State Univ., Fort Collins, CO (United States)

    1994-12-31

    Several modeling techniques of various complexity and accuracy are applied in a numerical modeling study of regional air pollution transport being performed within the Measurement Of Haze And Visual Effect (MOHAVE) project. The goal of this study is to assess the impact of the Mohave Power Project (MPP) and other potential sources of air pollution to specific Class I areas located in the desert southwest United States including the Grand Canyon National Park. The Colorado State University team is performing the daily meteorological and dispersion simulations for a year long study using a nonhydrostatic mesoscale meteorological model; the Regional Atmospheric Modeling System (RAMS) coupled with a Lagrangian particle dispersion (LPD) model. The modeling domain covers the southwestern United States with its extremely complex terrain. Two complementary dispersion modeling techniques: a traditional source-oriented approach and receptor-oriented approach are used to calculate concentration and influence function fields, respectively. All computations are performed on two IBM RISC-6000 workstations dedicated to the project. The goal of this paper is to present our design for daily dispersion simulations with an emphasis on influence function calculations using examples from the winter and summer intensive periods of the MOHAVE project.

  20. Identifying Groundwater Recharge in Arid Regions

    Science.gov (United States)

    Thomas, B. F.; Famiglietti, J. S.

    2015-12-01

    Recharge epodicity in arid regions provides a method to estimate annual groundwater recharge given a relationship expressed as the recharge to precipitation ratio. Traditionally, in-situ observations are required to identify aquifer recharge events, while more advanced approaches such as the water-table fluctuation method or the episodic master recession method are necessary to delineate the recharge event. Our study uses the Gravity Recovery and Climate Experiment (GRACE) observations to estimate monthly changes in groundwater storage which are attributed to the combination of groundwater abstraction and episodic recharge in the arid southwestern United States. Our results illustrate the ability of remote sensing technologies to identify episodic groundwater recharge in arid regions which can be used within sustainable groundwater management frameworks to effectively manage groundwater resources.

  1. Geothermal development and production of electricity in the Southwestern United States

    Energy Technology Data Exchange (ETDEWEB)

    Nowotny, K.R.; Rao, C.R.

    1978-10-01

    A computer simulation model (GIRORA-Electric) is developed to study the economics of power generation from high temperature geothermal resources. GIRORA-Electric is a discounted cash flow investment model which evaluates the rate of return on producers' capital investment. This model consists of two major submodels: the exploration and development of a geothermal anomaly by a producer; and the purchase of geothermal fluid by a utility developer. The primary output of the model is a calculated rate of return on the capital investment earned by the geothermal producer. The results of the sensitivity analysis of the model subject to changes in physical and economic parameters are given. Using the results of the economic analysis, the high temperature geothermal sites (temperatures greater than 150/sup 0/C) in the Southwestern United States are examined for economic viability for power generation. The total amount of power that can be brought on line in the Southwest Region is estimated under three different scenario assumptions. An econometric model is developed to estimate the total demand for electricity in the Southwest Region. From this demand and supply estimates, the amount of geothermal energy that can be utilized is also estimated.

  2. Seismic discontinuities beneath the southwestern United States from S receiver functions

    Science.gov (United States)

    Akanbi, Olufemi; Li, Aibing

    2016-05-01

    S-receiver functions along the Colorado Plateau-Rio Grande Rift-Great Plains Transect known as LA RISTRA in the southwestern United States have been utilized to map seismic discontinuities beneath this tectonically active region. Individual receiver functions were stacked according to ray piercing points with moveout corrections in order to improve the signal-to-noise ratio of the converted S-to-P phases. A mantle discontinuity, which is interpreted as the lithosphere-asthenosphere boundary (LAB), is observed along the profile with depth ranging from 80 km beneath the Rio Grande Rift (RGR) to 100 km beneath the Great Plains (GP) and 120-180 km beneath the Colorado Plateau (CP). The shallow LAB beneath the Rio Grande Rift is indicative of lithosphere extension and asthenosphere upwarp. The LAB deepens sharply at the RGR-CP and RGR-GP boundaries, providing evidence for edge-driven, small-scale mantle convection beneath LA RISTRA. Two local discontinuities beneath the southeastern Colorado Plateau are imaged at ~ 250 km and ~ 300 km and could be the top and base of the eroded lithosphere, respectively. The S receiver function images suggest that edge-driven, small-scale convection is probably the mantle source for recent extension and uplift in the Rio Grande Rift and the Colorado Plateau.

  3. Trace metals in soils of the main geomorphological units in the southwestern part of Western Siberia

    Science.gov (United States)

    Konstantinova, E. Yu

    2016-09-01

    Total concentrations of Ti, Cr, Mn, Ni, Cu, Zn, Rb, Sr, and Pb as well as soil granulometric texture were studied for three plot sites representing different geomorphologic units of the southwestern part of Western Siberia: periphery of the upland Tobolsky Mainland, Ishim plain, Turinskaya plain. Interregional difference in the relationship by and among the content of trace elements and particle size distribution of soil horizons is established. Thus, for the soils of Turinskaya plain such interrelations are not observed. For the soils of Ishim Plain moderate negative correlation between Pb concentrations and medium silt, as well as average positive correlations between Zn and fine sand, coarse sand and Pb are found. For the soils of the high terraces of the Irtish and periphery of Tobolsky Mainland interface zone moderate positive correlations between contents of Ti, Zn, Sr and fine sand, weak positive ones between Rb and medium sand, moderate negative ones between Zn and clay, Ti, Ni, Cu, Zn, Rb, Sr, and fine dust, Ti, Cu, Zn, Rb, Sr and medium silt are observed. Consequently, properties and genesis of local parent rocks are significant factors for distribution and accumulation of trace elements in the soils of the southern taiga; at the same time, the processes of bioaccumulation in thick humus horizons of dark gray soils and chernozems apparently play an important part in accumulation and migration of trace elements in forest-steppe soils of Ishim and Turinskaya plains.

  4. Management implications of the ecology of free-roaming horses in semi-arid ecosystems of the western United States

    Science.gov (United States)

    Beever, Erik A.

    2003-01-01

    Compared to other ungulates of North America, free-roaming horses (Equus caballus) possess a unique evolutionary history that has given rise to a distinct suite of behavioral, morphological, and physiological traits. Because of their unique combination of cecal digestion, an elongate head with flexible lips, and non-uniform use of the landscape, horses represent a unique disturbance agent in semi-arid ecosystems of the western United States. Consequently, it is inappropriate to assume that influences of horses on the structure, composition, function, and pattern of arid and semi-arid ecosystems will mirror influences of cattle or other artiodactyls. Although management areas for free-roaming horses occupy 18.6 million ha of land across western North America, we know relatively little about how western ecosystems and their components have responded to this uniquely managed ungulate. I draw on my research of horse habitats in the western Great Basin (U.S.A.) to examine predictions of horses' unique influence, and advocate for continued research to refine our understanding of synecological relationships among horses and diverse ecosystem components in arid and semi-arid regions.

  5. A hybrid statistical-dynamical framework for meteorological drought prediction: Application to the southwestern United States

    Science.gov (United States)

    Madadgar, Shahrbanou; AghaKouchak, Amir; Shukla, Shraddhanand; Wood, Andrew W.; Cheng, Linyin; Hsu, Kou-Lin; Svoboda, Mark

    2016-07-01

    Improving water management in water stressed-regions requires reliable seasonal precipitation predication, which remains a grand challenge. Numerous statistical and dynamical model simulations have been developed for predicting precipitation. However, both types of models offer limited seasonal predictability. This study outlines a hybrid statistical-dynamical modeling framework for predicting seasonal precipitation. The dynamical component relies on the physically based North American Multi-Model Ensemble (NMME) model simulations (99 ensemble members). The statistical component relies on a multivariate Bayesian-based model that relates precipitation to atmosphere-ocean teleconnections (also known as an analog-year statistical model). Here the Pacific Decadal Oscillation (PDO), Multivariate ENSO Index (MEI), and Atlantic Multidecadal Oscillation (AMO) are used in the statistical component. The dynamical and statistical predictions are linked using the so-called Expert Advice algorithm, which offers an ensemble response (as an alternative to the ensemble mean). The latter part leads to the best precipitation prediction based on contributing statistical and dynamical ensembles. It combines the strength of physically based dynamical simulations and the capability of an analog-year model. An application of the framework in the southwestern United States, which has suffered from major droughts over the past decade, improves seasonal precipitation predictions (3-5 month lead time) by 5-60% relative to the NMME simulations. Overall, the hybrid framework performs better in predicting negative precipitation anomalies (10-60% improvement over NMME) than positive precipitation anomalies (5-25% improvement over NMME). The results indicate that the framework would likely improve our ability to predict droughts such as the 2012-2014 event in the western United States that resulted in significant socioeconomic impacts.

  6. Projecting climate effects on birds and reptiles of the Southwestern United States

    Science.gov (United States)

    van Riper, Charles; Hatten, James R.; Giermakowski, J. Tomasz; Mattson, David; Holmes, Jennifer A.; Johnson, Matthew J.; Nowak, Erika M.; Ironside, Kirsten; Peters, Michael; Heinrich, Paul; Cole, K.L.; Truettner, C.; Schwalbe, Cecil R.

    2014-01-01

    We modeled the current and future breeding ranges of seven bird and five reptile species in the Southwestern United States with sets of landscape, biotic (plant), and climatic global circulation model (GCM) variables. For modeling purposes, we used PRISM data to characterize the climate of the Western United States between 1980 and 2009 (baseline for birds) and between 1940 and 2009 (baseline for reptiles). In contrast, we used a pre-selected set of GCMs that are known to be good predictors of southwestern climate (five individual and one ensemble GCM), for the A1B emission scenario, to characterize future climatic conditions in three time periods (2010–39; 2040–69; and, 2070–99). Our modeling approach relied on conceptual models for each target species to inform selection of candidate explanatory variables and to interpret the ecological meaning of developed probabilistic distribution models. We employed logistic regression and maximum entropy modeling techniques to create a set of probabilistic models for each target species. We considered climatic, landscape, and plant variables when developing and testing our probabilistic models. Climatic variables included the maximum and minimum mean monthly and seasonal temperature and precipitation for three time periods. Landscape features included terrain ruggedness and insolation. We also considered plant species distributions as candidate explanatory variables where prior ecological knowledge implicated a strong association between a plant and animal species. Projected changes in range varied widely among species, from major losses to major gains. Breeding bird ranges exhibited greater expansions and contractions than did reptile species. We project range losses for Williamson’s sapsucker and pygmy nuthatch of a magnitude that could move these two species close to extinction within the next century. Although both species currently have a relatively limited distribution, they can be locally common, and neither

  7. Predicted nitrate and arsenic concentrations in basin-fill aquifers of the Southwestern United States

    Science.gov (United States)

    Anning, David W.; Paul, Angela P.; McKinney, Tim S.; Huntington, Jena M.; Bexfield, Laura M.; Thiros, Susan A.

    2012-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) is conducting a regional analysis of water quality in the principal aquifer systems across the United States. The Southwest Principal Aquifers (SWPA) study is building a better understanding of the susceptibility and vulnerability of basin-fill aquifers in the region to groundwater contamination by synthesizing baseline knowledge of groundwater-quality conditions in 16 basins previously studied by the NAWQA Program. The improved understanding of aquifer susceptibility and vulnerability to contamination is assisting in the development of tools that water managers can use to assess and protect the quality of groundwater resources. About 46.6 million people live in the SWPA study area, mostly in urban areas, but also in rural, agricultural communities that cultivate about 14.4 million acres of cropland. Other rural areas contain small communities with mining, retirement, or tourism/recreational-based economies. Because of the generally limited availability of surface-water supplies in the arid to semiarid climate, cultural and economic activities in the region are particularly dependent on good-quality groundwater supplies. In the year 2000, about 33.7 million acre-feet (acre-ft) of surface water was diverted from streams, and about 23.0 million acre-ft of groundwater was withdrawn from basin-fill aquifers in the SWPA study area. Irrigation and public-supply withdrawals from basin-fill aquifers in the study area for 2000 were about 18.0 million acre-ft and 4.1 million acre-ft, respectively, and together account for about one quarter of the total withdrawals from all aquifers in the United States. Although irrigation and public supply are the primary uses of basin-fill aquifer withdrawals in the study area, water use varies locally by basin, and withdrawals for industrial, mining, and electric power generation also are substantial in some areas.

  8. MACROINVERTEBRATE SAMPLING TECHNIQUES FOR STREAMS IN SEMI-ARID REGIONS. COMPARISON OF THE SURBER METHOD AND A UNIT-EFFORT TRAVELING KICK METHOD

    Science.gov (United States)

    Streams of the arid and semi-arid regions of the western United States are characterized by irregular flow patterns resulting in highly unstable macroinvertebrate habitats and a sparse macrobenthic fauna. The use of a standard square-foot Surber stream-bottom sampler is of limite...

  9. Desert grassland responses to climate and soil moisture suggest divergent vulnerabilities across the southwestern United States.

    Science.gov (United States)

    Gremer, Jennifer R; Bradford, John B; Munson, Seth M; Duniway, Michael C

    2015-11-01

    Climate change predictions include warming and drying trends, which are expected to be particularly pronounced in the southwestern United States. In this region, grassland dynamics are tightly linked to available moisture, yet it has proven difficult to resolve what aspects of climate drive vegetation change. In part, this is because it is unclear how heterogeneity in soils affects plant responses to climate. Here, we combine climate and soil properties with a mechanistic soil water model to explain temporal fluctuations in perennial grass cover, quantify where and the degree to which incorporating soil water dynamics enhances our ability to understand temporal patterns, and explore the potential consequences of climate change by assessing future trajectories of important climate and soil water variables. Our analyses focused on long-term (20-56 years) perennial grass dynamics across the Colorado Plateau, Sonoran, and Chihuahuan Desert regions. Our results suggest that climate variability has negative effects on grass cover, and that precipitation subsidies that extend growing seasons are beneficial. Soil water metrics, including the number of dry days and availability of water from deeper (>30 cm) soil layers, explained additional grass cover variability. While individual climate variables were ranked as more important in explaining grass cover, collectively soil water accounted for 40-60% of the total explained variance. Soil water conditions were more useful for understanding the responses of C3 than C4 grass species. Projections of water balance variables under climate change indicate that conditions that currently support perennial grasses will be less common in the future, and these altered conditions will be more pronounced in the Chihuahuan Desert and Colorado Plateau. We conclude that incorporating multiple aspects of climate and accounting for soil variability can improve our ability to understand patterns, identify areas of vulnerability, and predict

  10. Application of data on climate extremes for the southwestern United States

    Science.gov (United States)

    Redmond, K. T.; Fleishman, E.; Cayan, D. R.; Daudert, B.; Gershunov, A.

    2015-12-01

    We are improving the scientific capacity to evaluate responses of natural resources to climate extremes. We also are enhancing a platform for derivation of and access to customized climate information for the full extent or any subset of the southwestern United States. Extreme climate can have substantial effects on species, ecological and evolutionary processes, and the health of visitors to public lands. We are working with federal and state managers and with researchers who collaborate with decision-makers to use data on climate extremes to inform resource management. Current applications include sudden oak death, estuarine management, and fine-resolution manipulation of montane vegetation. To facilitate practical use of data on climate extremes, we are screening global climate models on the basis of their realism in representing natural regional patterns and extremes of temperature and precipitation, including those driven by El Niño and La Niña. We are assessing how well each model represents different climate elements. We also are delivering point and gridded observations and downscaled model projections, all at daily and 6 km resolution, on past and future climate extremes. Additionally, we are using the downscaled outputs to drive a hydrologic model and derive multiple probabilistic measures of water availability, flood, and drought. Moreover, we are extending the capacity of the Southwest Climate and Environmental Information Collaborative (SCENIC; wrcc.dri.edu/csc/scenic), a product developed by the Western Regional Climate Center, to provide access to diverse observed and simulated data on regional weather and climate, particularly on extremes.

  11. Desert grassland responses to climate and soil moisture suggest divergent vulnerabilities across the southwestern United States.

    Science.gov (United States)

    Gremer, Jennifer R; Bradford, John B; Munson, Seth M; Duniway, Michael C

    2015-11-01

    Climate change predictions include warming and drying trends, which are expected to be particularly pronounced in the southwestern United States. In this region, grassland dynamics are tightly linked to available moisture, yet it has proven difficult to resolve what aspects of climate drive vegetation change. In part, this is because it is unclear how heterogeneity in soils affects plant responses to climate. Here, we combine climate and soil properties with a mechanistic soil water model to explain temporal fluctuations in perennial grass cover, quantify where and the degree to which incorporating soil water dynamics enhances our ability to understand temporal patterns, and explore the potential consequences of climate change by assessing future trajectories of important climate and soil water variables. Our analyses focused on long-term (20-56 years) perennial grass dynamics across the Colorado Plateau, Sonoran, and Chihuahuan Desert regions. Our results suggest that climate variability has negative effects on grass cover, and that precipitation subsidies that extend growing seasons are beneficial. Soil water metrics, including the number of dry days and availability of water from deeper (>30 cm) soil layers, explained additional grass cover variability. While individual climate variables were ranked as more important in explaining grass cover, collectively soil water accounted for 40-60% of the total explained variance. Soil water conditions were more useful for understanding the responses of C3 than C4 grass species. Projections of water balance variables under climate change indicate that conditions that currently support perennial grasses will be less common in the future, and these altered conditions will be more pronounced in the Chihuahuan Desert and Colorado Plateau. We conclude that incorporating multiple aspects of climate and accounting for soil variability can improve our ability to understand patterns, identify areas of vulnerability, and predict

  12. High-resolution, regional-scale crop yield simulations for the Southwestern United States

    Science.gov (United States)

    Stack, D. H.; Kafatos, M.; Medvigy, D.; El-Askary, H. M.; Hatzopoulos, N.; Kim, J.; Kim, S.; Prasad, A. K.; Tremback, C.; Walko, R. L.; Asrar, G. R.

    2012-12-01

    Over the past few decades, there have been many process-based crop models developed with the goal of better understanding the impacts of climate, soils, and management decisions on crop yields. These models simulate the growth and development of crops in response to environmental drivers. Traditionally, process-based crop models have been run at the individual farm level for yield optimization and management scenario testing. Few previous studies have used these models over broader geographic regions, largely due to the lack of gridded high-resolution meteorological and soil datasets required as inputs for these data intensive process-based models. In particular, assessment of regional-scale yield variability due to climate change requires high-resolution, regional-scale, climate projections, and such projections have been unavailable until recently. The goal of this study was to create a framework for extending the Agricultural Production Systems sIMulator (APSIM) crop model for use at regional scales and analyze spatial and temporal yield changes in the Southwestern United States (CA, AZ, and NV). Using the scripting language Python, an automated pipeline was developed to link Regional Climate Model (RCM) output with the APSIM crop model, thus creating a one-way nested modeling framework. This framework was used to combine climate, soil, land use, and agricultural management datasets in order to better understand the relationship between climate variability and crop yield at the regional-scale. Three different RCMs were used to drive APSIM: OLAM, RAMS, and WRF. Preliminary results suggest that, depending on the model inputs, there is some variability between simulated RCM driven maize yields and historical yields obtained from the United States Department of Agriculture (USDA). Furthermore, these simulations showed strong non-linear correlations between yield and meteorological drivers, with critical threshold values for some of the inputs (e.g. minimum and

  13. Identifying bird and reptile vulnerabilities to climate change in the southwestern United States

    Science.gov (United States)

    Hatten, James R.; Giermakowski, J. Tomasz; Holmes, Jennifer A.; Nowak, Erika M.; Johnson, Matthew J.; Ironside, Kirsten E.; Van Riper, Charles; Peters, Michael; Truettner, Charles; Cole, Kenneth L.

    2016-07-06

    Current and future breeding ranges of 15 bird and 16 reptile species were modeled in the Southwestern United States. Rather than taking a broad-scale, vulnerability-assessment approach, we created a species distribution model (SDM) for each focal species incorporating climatic, landscape, and plant variables. Baseline climate (1940–2009) was characterized with Parameter-elevation Regressions on Independent Slopes Model (PRISM) data and future climate with global-circulation-model data under an A1B emission scenario. Climatic variables included monthly and seasonal temperature and precipitation; landscape variables included terrain ruggedness, soil type, and insolation; and plant variables included trees and shrubs commonly associated with a focal species. Not all species-distribution models contained a plant, but if they did, we included a built-in annual migration rate for more accurate plant-range projections in 2039 or 2099. We conducted a group meta-analysis to (1) determine how influential each variable class was when averaged across all species distribution models (birds or reptiles), and (2) identify the correlation among contemporary (2009) habitat fragmentation and biological attributes and future range projections (2039 or 2099). Projected changes in bird and reptile ranges varied widely among species, with one-third of the ranges predicted to expand and two-thirds predicted to contract. A group meta-analysis indicated that climatic variables were the most influential variable class when averaged across all models for both groups, followed by landscape and plant variables (birds), or plant and landscape variables (reptiles), respectively. The second part of the meta-analysis indicated that numerous contemporary habitat-fragmentation (for example, patch isolation) and biological-attribute (for example, clutch size, longevity) variables were significantly correlated with the magnitude of projected range changes for birds and reptiles. Patch isolation was

  14. Identifying bird and reptile vulnerabilities to climate change in the southwestern United States

    Science.gov (United States)

    Hatten, James R.; Giermakowski, J. Tomasz; Holmes, Jennifer A.; Nowak, Erika M.; Johnson, Matthew J.; Ironside, Kirsten E.; Van Riper, Charles, III; Peters, Michael; Truettner, Charles; Cole, Kenneth L.

    2016-01-01

    Current and future breeding ranges of 15 bird and 16 reptile species were modeled in the Southwestern United States. Rather than taking a broad-scale, vulnerability-assessment approach, we created a species distribution model (SDM) for each focal species incorporating climatic, landscape, and plant variables. Baseline climate (1940–2009) was characterized with Parameter-elevation Regressions on Independent Slopes Model (PRISM) data and future climate with global-circulation-model data under an A1B emission scenario. Climatic variables included monthly and seasonal temperature and precipitation; landscape variables included terrain ruggedness, soil type, and insolation; and plant variables included trees and shrubs commonly associated with a focal species. Not all species-distribution models contained a plant, but if they did, we included a built-in annual migration rate for more accurate plant-range projections in 2039 or 2099. We conducted a group meta-analysis to (1) determine how influential each variable class was when averaged across all species distribution models (birds or reptiles), and (2) identify the correlation among contemporary (2009) habitat fragmentation and biological attributes and future range projections (2039 or 2099). Projected changes in bird and reptile ranges varied widely among species, with one-third of the ranges predicted to expand and two-thirds predicted to contract. A group meta-analysis indicated that climatic variables were the most influential variable class when averaged across all models for both groups, followed by landscape and plant variables (birds), or plant and landscape variables (reptiles), respectively. The second part of the meta-analysis indicated that numerous contemporary habitat-fragmentation (for example, patch isolation) and biological-attribute (for example, clutch size, longevity) variables were significantly correlated with the magnitude of projected range changes for birds and reptiles. Patch isolation was

  15. District space heating potential of low temperature hydrothermal geothermal resources in the southwestern United States. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    McDevitt, P.K.; Rao, C.R.

    1978-10-01

    A computer simulation model (GIRORA-Nonelectric) is developed to study the economics of district space heating using geothermal energy. GIRORA-Nonelectric is a discounted cashflow investment model which evaluates the financial return on investment for space heating. This model consists of two major submodels: the exploration for and development of a geothermal anomaly by a geothermal producer, and the purchase of geothermal fluid by a district heating unit. The primary output of the model is a calculated rate of return on investment earned by the geothermal producer. The results of the sensitivity analysis of the model subject to changes in physical and economic parameters are given in this report. Using the results of the economic analysis and technological screening criteria, all the low temperature geothermal sites in Southwestern United States are examined for economic viability for space heating application. The methodology adopted and the results are given.

  16. Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Natural Asbestos Occurrences in the Southwestern United States (Arizona, Nevada, and Utah)

    Science.gov (United States)

    Van Gosen, Bradley S.

    2008-01-01

    This map and its accompanying dataset provide information for 113 natural asbestos occurrences in the Southwestern United States (U.S.), using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Southwestern U.S., which includes sites in Arizona, Nevada, and Utah. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the U.S., which thus far includes similar maps and datasets of natural asbestos occurrences within the Eastern U.S. (http://pubs.usgs.gov/of/2005/1189/), the Central U.S. (http://pubs.usgs.gov/of/2006/1211/), and the Rocky Mountain States (http://pubs.usgs.gov/of/2007/1182/. These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the U.S.

  17. Water use and supply concerns for utility-scale solar projects in the Southwestern United States.

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Geoffrey Taylor; Tidwell, Vincent Carroll; Reno, Marissa Devan; Moreland, Barbara Denise.; Zemlick, Katie M.; Macknick, Jordan

    2013-07-01

    As large utility-scale solar photovoltaic (PV) and concentrating solar power (CSP) facilities are currently being built and planned for locations in the U.S. with the greatest solar resource potential, an understanding of water use for construction and operations is needed as siting tends to target locations with low natural rainfall and where most existing freshwater is already appropriated. Using methods outlined by the Bureau of Land Management (BLM) to determine water used in designated solar energy zones (SEZs) for construction and operations & maintenance, an estimate of water used over the lifetime at the solar power plant is determined and applied to each watershed in six Southwestern states. Results indicate that that PV systems overall use little water, though construction usage is high compared to O&M water use over the lifetime of the facility. Also noted is a transition being made from wet cooled to dry cooled CSP facilities that will significantly reduce operational water use at these facilities. Using these water use factors, estimates of future water demand for current and planned solar development was made. In efforts to determine where water could be a limiting factor in solar energy development, water availability, cost, and projected future competing demands were mapped for the six Southwestern states. Ten watersheds, 9 in California, and one in New Mexico were identified as being of particular concern because of limited water availability.

  18. Increased Extreme Hydrological Events and Decreased Water Supply Availability for the Southwestern United States Projected by Mid-Century

    Science.gov (United States)

    Pagan, B. R.; Ashfaq, M.; Rastogi, D.; Naz, B. S.; Kao, S. C.; Mei, R.; Kendall, D. R.; Pal, J. S.

    2015-12-01

    Semi-arid Southern California relies primarily on imported water originating mostly from snowpack in basins outside of the region including the San-Joaquin River, Tulare Lake, Sacramento River, Owens Valley, Mono Lake, and Colorado River basins. This study provides an integrated ensemble approach to assessing climate change impacts on the hydrologic cycle and hydrologic extremes for all water supplies to Southern California. Output from 10 global climate models is used to force a regional climate model and hydrological model resulting in high-resolution 4.17-km output for the region. Greenhouse gas concentrations are prescribed according to historical values for the present-day (1965-2005) and the IPCC Representative Concentration Pathway 8.5 for the near to mid term future (2010-2050). On the annual timescale, temperature, precipitation and evaporation increase throughout the majority of the study area. With increased temperatures, precipitation is less likely to fall as snow, decreasing snowpack and natural storage and shifting peak flows to earlier in the year. Daily annual maximum runoff and precipitation events are projected to significantly increase in intensity and frequency by mid-century. The 50-year event, for example, becomes approximately five times more likely in the Colorado River basin and twice as likely in the other basins. In densely populated coastal Southern Californian cities, extreme flood events become three to five times as likely substantially increasing the risk of overburdening flood control systems and potential widespread flooding. The escalating likelihood of the combined effects of runoff occurring earlier in the year and in significantly higher amounts poses a substantial flood control risk requiring adaptation measures such as water release from reservoirs. Significant snowpack reductions and increased flood risk will likely necessitate additional multiyear storage solutions for urban and agricultural regions in the Southwestern US.

  19. National Assessment of Oil and Gas Project - Southwestern Wyoming Province (037) Assessment Units

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is...

  20. Prospects for phenological monitoring in an arid southwestern U.S. rangeland using field observations with hyperspatial and moderate resolution imagery

    Science.gov (United States)

    Browning, D. M.; Laliberte, A. S.; Rango, A.; Herrick, J. E.

    2009-12-01

    Relating field observations of plant phenological events to remotely sensed depictions of land surface phenology remains a challenge to the vertical integration of data from disparate sources. This research conducted at the Jornada Basin Long-Term Ecological Research site in southern New Mexico capitalizes on legacy datasets pertaining to reproductive phenology and biomass and hyperspatial imagery. Large amounts of exposed bare soil and modest cover from shrubs and grasses in these arid and semi-arid ecosystems challenge the integration of field observations of phenology and remotely sensed data to monitor changes in land surface phenology. Drawing on established field protocols for reproductive phenology, hyperspatial imagery (4 cm), and object-based image analysis, we explore the utility of two approaches to scale detailed observations (i.e., field and 4 cm imagery) to the extent of long-term field plots (50 x 50m) and moderate resolution Landsat Thematic Mapper (TM) imagery (30 x 30m). Very high resolution color-infrared imagery was collected June 2007 across 15 LTER study sites that transect five distinct vegetation communities along a continuum of grass to shrub dominance. We examined two methods for scaling spectral vegetation indices (SVI) at 4 cm resolution: pixel averaging and object-based integration. Pixel averaging yields the mean SVI value for all pixels within the plot or TM pixel. Alternatively, the object-based method is based on a weighted average of SVI values that correspond to discrete image objects (e.g., individual shrubs or grass patches). Object-based image analysis of 4 cm imagery provides a detailed depiction of ground cover and allows us to extract species-specific contributions to upscaled SVI values. The ability to discern species- or functional-group contributions to remotely sensed signals of vegetation greenness can greatly enhance the design of field sampling protocols for phenological research. Furthermore, imagery from unmanned

  1. Simple equation for estimating actual evapotranspiration using heat units for wheat in arid regions

    Directory of Open Access Journals (Sweden)

    M.A. Salama

    2015-07-01

    Application of treatment (B resulted in highly significant increase in yield production of Gemmeza10 and Misr2 as compared to treatment (A. Grain yield of different wheat varieties grown under treatment (B could be ranked in the following descending order: Misr2 > Gemmeza10 > Sids12. While under treatment (A it could be arranged in the following descending order: Misr2 > Sids12 > Gemmeza10. On the other hand, the overall means indicated non-significant difference between all wheat verities. The highest values of water and irrigation use efficiency as well as heat use efficiency were obtained with treatment (B. The equation used in the present study is available to estimate ETa under arid climate with drip irrigation system.

  2. Coevolution of topography, hydrology, soil development, and vegetation in sky islands of the southwestern United States

    Science.gov (United States)

    Pelletier, J. D.; Rasmussen, C.; Breshears, D. D.; Brooks, P. D.; Chorover, J.; Huxman, T. E.; Lohse, K. A.; Meixner, T.; McIntosh, J. C.; Kurc, S. A.; Schaap, M. G.; Swetnam, T.; Troch, P. A.; University Of Arizona Czo

    2010-12-01

    The sky islands of the southwestern U.S. offer a unique opportunity to study the coevolution of landscape processes in areas of similar rock type and tectonic history but a wide range of climates. In this study we compile high-resolution, spatially-distributed data for the available energy to drive rock weathering and other landscape processes, i.e. the Effective Energy and Mass Transfer (EEMT) variable of Rasmussen and Tabor (2005), together with data for LiDAR-derived above-ground biomass, soil thickness, water storage potential, hillslope relief, and valley density in the Santa Catalina and Pinaleno Mountains, two predominantly granitic ranges in southern Arizona. Strong correlations exist among these variables such that warm, dry, low elevation portions of these areas are characterized by low biomass, thin soils, low water-storage potential, steep slopes, and high valley densities. Cooler, wetter, higher-elevation portions have systematically higher biomass, thicker soils, higher water-storage potential, gentler slopes, and lower valley densities. Moreover, all of these variables have a nonlinear dependence on climate/elevation. Slope gradient and aspect also exert an important control on these variables, with steep, south-facing hillslopes characterized by drier-than-average conditions for a given elevation and north-facing slopes associated with wetter-than-average conditions. We hypothesize that these correlations partly reflect coevolutionary positive-feedback mechanisms among these processes that amplify differences in rates set by climate, tectonics, and rock type. For example, thicker soils with higher water storage potential that form at higher elevations/north-facing slopes tend to have greater biomass, causing lower runoff ratios, lower rates of slopewash and fluvial erosion, and increased rates of colluvial transport, thereby promoting thicker soils, lower-gradient slopes, and lower valley densities. Thicker soils and higher water storage potentials

  3. Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth

    Science.gov (United States)

    Connin, S.L.; Betancourt, J.; Quade, Jay

    1998-01-01

    Patterns of climate and C4 plant abundance in the southwestern United States during the last glaciation were evaluated from isotopic study of herbivore tooth enamel. Enamel ??13C values revealed a substantial eastward increase in C4 plant consumption for Mammuthus spp., Bison spp., Equus spp., and Camelops spp. The ??13C values were greatest in Bison spp. (-6.9 to + 1.7???) and Mammuthus spp. (-9.0 to +0.3???), and in some locales indicated C4-dominated grazing. The ??13C values of Antilocaprids were lowest among taxa (-12.5 to -7.9???) and indicated C3 feeding at all sites. On the basis of modern correlations between climate and C4 grass abundance, the enamel data imply significant summer rain in parts of southern Arizona and New Mexico throughout the last glaciation. Enamel ??18O values range from +19.0 to +31.0??? and generally increase to the east. This pattern could point to a tropical or subtropical source of summer rainfall. At a synoptic scale, the isotope data indicate that interactions of seasonal moisture, temperature, and lowered atmospheric pCO2 determined glacial-age C4 abundance patterns.

  4. Solar energy development and aquatic ecosystems in the southwestern United States: potential impacts, mitigation, and research needs.

    Science.gov (United States)

    Grippo, Mark; Hayse, John W; O'Connor, Ben L

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  5. Solar Energy Development and Aquatic Ecosystems in the Southwestern United States: Potential Impacts, Mitigation, and Research Needs

    Science.gov (United States)

    Grippo, Mark; Hayse, John W.; O'Connor, Ben L.

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  6. Urban vegetation and income segregation in drylands: a synthesis of seven metropolitan regions in the southwestern United States

    International Nuclear Information System (INIS)

    To better understand how urbanization affects the amount and timing of urban vegetation in drylands we investigated remotely sensed vegetation patterns across seven large metropolitan regions in the southwestern United States. We asked (1) how low density urban land cover differed from adjacent wildland grass, herb, and shrub land covers in both the amount of vegetation and the length of the growing season, (2) how neighborhood income affected patterns of vegetation within low density urban cover, and (3) how cities differed from one another in their vegetation patterns. We found that urbanization generally has a strong influence on vegetation compared to adjacent wildlands. In four of the metropolitan regions the cumulative enhanced vegetation index (EVI) and growing season length in low density developments were higher than grass, herb, and shrub land covers. Within all metropolitan regions, there was a significant socioeconomic effect where higher income areas had a higher cumulative EVI than lower income areas. The large differences in urban vegetation among cities were related to precipitation and total domestic water use. These findings help to identify how urbanization influences vegetation, with implications for the availability of ecosystem services and requirements for irrigation in hot dryland cities. (letter)

  7. Multiple oxygen and sulfur isotopic analyses on water-soluble sulfate in bulk atmospheric deposition from the southwestern United States

    Science.gov (United States)

    Bao, H.; Reheis, M.C.

    2003-01-01

    Sulfate is a major component of bulk atmospheric deposition (including dust, aerosol, fog, and rain). We analyzed sulfur and oxygen isotopic compositions of water-soluble sulfate from 40 sites where year-round dust traps collect bulk atmospheric deposition in the southwestern United States. Average sulfur and oxygen isotopic compositions (??34S and ??18O) are 5.8 ?? 1.4 (CDT) and 11.2 ?? 1.9 (SMOW) (n = 47), respectively. Samples have an oxygen 17 anomaly (?? 17O), with an average value of 1.0 ?? 0.6???. Except for a weak positive correlation between ??18O and ??17O values (r2 ??? 0.4), no correlation exists for ??18O versus ??34S, ?? 17O versus ??34S, or any of the three isotopic compositions versus elevation of the sample site. Exceptional positive ?? 17O values (up to 4.23???) are found in samples from sites in the vicinity of large cities or major highways, and near-zero ?? 17O values are found in samples close to dry lakes. Comparison of isotopic values of dust trap sulfate and desert varnish sulfate from the region reveals that varnish sulfate has average isotopic values that are ???4.8??? lower for ??18O, ???2.1??? higher for ??34S , and ???0.3??? lower for ?? 17O than those of the present-day bulk deposition sulfate. Although other factors could cause the disparity, this observation suggests a possibility that varnish sulfate may have recorded a long-term atmospheric sulfate deposition during the Holocene or Pleistocene, as well as the differences between sulfur and oxygen isotopic compositions of the preindustrial bulk deposition sulfate and those of the industrial era.

  8. A 1300 Year Sub-Decadally Resolved Hydrologic Record from the Coastal Southwestern United States (Crystal Lake, CA)

    Science.gov (United States)

    Palermo, J. A.; Kirby, M. E.

    2015-12-01

    This study presents a 1300 year sub-decadally resolved record of hydrologic variability from coastal southwestern United States (Crystal Lake, CA). Crystal Lake is a small (0.02 km2), alpine landslide dammed lake in the Angeles National Forest of the San Gabriel Mountains. The hydrologically closed lake is the only permanent, freshwater lake in the range; its catchment is small (0.77 km2). In May 2014, lake depth measured 5.5 m, however the spillover point in the southeastern end of the lake indicates a max depth of ~50 m. Two Livingston piston cores were taken in May 2014, 15 m apart in the lake's depocenter. Magnetic susceptibility, LOI 550 °C and 950 °C, and grain size were measured at 1 cm contiguous intervals; C:N ratios and C and N isotopic analyses were measured every 2 cm. In addition, representative allochthonous and autochthonous vegetation were collected within the drainage basin for δ13Corg values. An age model was generated using Bacon v2.2, based on 11 AMS 14C dates of discrete organic matter (i.e. charcoal or wood). Age control for the past 200 years is based on correlation to Rothenberg et al. (2010) core ages. Initial results suggest a history of event sedimentation (large storms) superimposed on multi-decadal to centennial hydrologic changes (wet vs. dry periods) such as the Little Ice Age and the Medieval Climate Anomaly. Additionally, the Crystal Lake record is compared to preexisting regional records to further explore the record's spatial coherence. Mechanisms driving these hydrologic shifts are explored.

  9. A methodology to asess relations between climatic variability and variations in hydrologic time series in the southwestern United States

    Science.gov (United States)

    Hanson, R.T.; Newhouse, M.W.; Dettinger, M.D.

    2004-01-01

    A new method for frequency analysis of hydrologic time series was developed to facilitate the estimation and reconstruction of individual or groups of frequencies from hydrologic time-series and facilitate the comparison of these isolated time-series components across data types, between different hydrologic settings within a watershed, between watersheds, and across frequencies. While climate-related variations in inflow to and outflow from aquifers have often been neglected, the development and management of ground-water and surface-water resources has required the inclusion of the assessment of the effects of climatic variability on the supply and demand and sustainability of use. The regional assessment of climatic variability of surface-water and ground-water flow throughout the southwestern United States required this new systematic method of hydrologic time-series analysis. To demonstrate the application of this new method, six hydrologic time-series from the Mojave River Basin, California were analyzed. The results indicate that climatic variability exists in all the data types and are partially coincident with known climate cycles such as the Pacific Decadal Oscillation and the El Nino-Southern Oscillation. The time-series also indicate lagged correlations between tree-ring indices, streamflow, stream base flow, and ground-water levels. These correlations and reconstructed time-series can be used to better understand the relation of hydrologic response to climatic forcings and to facilitate the simulation of streamflow and ground-water recharge for a more realistic approach to water-resource management. Published by Elsevier B.V.

  10. Revisiting haboobs in the southwestern United States: An observational case study of the 5 July 2011 Phoenix dust storm

    Science.gov (United States)

    Raman, Aishwarya; Arellano, Avelino F.; Brost, John J.

    2014-06-01

    Convectively-driven dust storms (or haboobs) are common phenomena in the southwestern United States. However, studies about haboobs in this region are limited. Here, we investigate the state and fate of a massive haboob that hit Phoenix, Arizona on 5 July 2011 using satellite, radar, and ground-based observations. This haboob was a result of strong outflow boundaries (with peak wind gusts of 29 m s-1) from storms that were initiated in the southeast of Tucson. In particular, we find three major outflow systems (based on radar data) that were generated by forward propagating storms, ultimately merging near Phoenix. This resulted in peak hourly PM10 and PM2.5 concentrations of 1974 μg m-3 and 907 μg m-3 at US EPA stations near Phoenix. The high PM concentration is consistent in space and time with the dust wall movement based on our analysis of radar data on hydrometeor classification. Enhanced aerosol loadings over metropolitan Phoenix were also observed on 6 July from NASA Terra/Aqua MODIS aerosol optical depth (AOD) retrievals (AOD > 0.8). We infer from CALIOP vertical feature masks and HYSPLIT back trajectories that remnants of the haboob were transported to northwest of Phoenix on 6 July at 2-4 km above ground level. Ratios of PM2.5 to PM10 from IMPROVE stations also imply low-level transport to the east of Phoenix on 8 July. Finally, we find that this haboob, which had local and regional impacts, is atypical of other dust events in this region. We note from this analysis that extreme events such as this haboob require an integrated air quality observing system to provide a more comprehensive assessment of these events.

  11. Association of Bactericera cockerelli (Homoptera: Psyllidae) with "zebra chip," a new potato disease in southwestern United States and Mexico.

    Science.gov (United States)

    Munyaneza, J E; Crosslin, J M; Upton, J E

    2007-06-01

    A new defect of potato, Solanum tuberosum L., "zebra chip," so named for the characteristic symptoms that develop in fried chips from infected potato tubers, has recently been documented in several southwestern states of the United States, in Mexico, and in Central America. This defect is causing millions of dollars in losses to both potato producers and processors. Zebra chip plant symptoms resemble those caused by potato purple top and psyllid yellows diseases. Experiments were conducted to elucidate the association between the psyllid Bactericera cockerelli (Sulc) (Homoptera: Psyllidae) and zebra chip by exposing clean potato plants to this insect under greenhouse and field conditions. Potato plants and tubers exhibiting zebra chip symptoms were tested for phytoplasmas by polymerase chain reaction. Potato psyllids collected from infected potato fields also were tested. Results indicated that there was an association between the potato psyllid and zebra chip. Plants exposed to psyllids in the greenhouse and field developed zebra chip. In the greenhouse, 25.8 and 59.2% of tubers exhibited zebra chip symptoms in the raw tubers and fried chips, respectively. In the field, 15 and 57% of tubers showed symptoms in raw tubers and chips, respectively. No zebra chip was observed in tubers from plants that had not been exposed to psyllids, either in the greenhouse or field. No phytoplasmas were detected from potato plants or tubers with zebra chip symptoms, suggesting that these pathogens are not involved in zebra chip. Of the 47 samples of potato psyllids tested, only two tested positive for the Columbia Basin potato purple top phytoplasma. PMID:17598522

  12. Aerosol and precipitation chemistry in the southwestern United States: spatiotemporal trends and interrelationships

    Directory of Open Access Journals (Sweden)

    A. Sorooshian

    2013-04-01

    Full Text Available This study characterizes the spatial and temporal patterns of aerosol and precipitation composition at six sites across the United States Southwest between 1995 and 2010. Precipitation accumulation occurs mostly during the wintertime (December–February and during the monsoon season (July–September. Rain and snow pH levels are usually between 5–6, with crustal-derived species playing a major role in acid neutralization. These species (Ca2+, Mg2+, K+,Na+ exhibit their highest concentrations between March and June in both PM2.5 and precipitation due mostly to dust. Crustal-derived species concentrations in precipitation exhibit positive relationships with SO42−, NO3−, and Cl−, suggesting that acidic gases likely react with and partition to either crustal particles or hydrometeors enriched with crustal constituents. Concentrations of particulate SO42− show a statistically significant correlation with rain SO42− unlike snow SO42−, which may be related to some combination of the vertical distribution of SO42− (and precursors and the varying degree to which SO42−-enriched particles act as cloud condensation nuclei versus ice nuclei in the region. The coarse : fine aerosol mass ratio was correlated with crustal species concentrations in snow unlike rain, suggestive of a preferential role of coarse particles (mainly dust as ice nuclei in the region. Precipitation NO3− : SO42− ratios exhibit the following features with potential explanations discussed: (i they are higher in precipitation as compared to PM2.5; (ii they exhibit the opposite annual cycle compared to particulate NO3− : SO42− ratios; and (iii they are higher in snow relative to rain during the wintertime. Long-term trend analysis for the monsoon season shows that the NO3− : SO42− ratio in rain decreased at the majority of sites due mostly to air pollution regulations of SO42− precursors.

  13. Aerosol and precipitation chemistry in the southwestern United States: spatiotemporal trends and interrelationships

    Directory of Open Access Journals (Sweden)

    A. Sorooshian

    2013-08-01

    Full Text Available This study characterizes the spatial and temporal patterns of aerosol and precipitation composition at six sites across the United States Southwest between 1995 and 2010. Precipitation accumulation occurs mostly during the wintertime (December–February and during the monsoon season (July–September. Rain and snow pH levels are usually between 5–6, with crustal-derived species playing a major role in acid neutralization. These species (Ca2+, Mg2+, K+, Na+ exhibit their highest concentrations between March and June in both PM2.5 and precipitation due mostly to dust. Crustal-derived species concentrations in precipitation exhibit positive relationships with SO42−, NO3−, and Cl−, suggesting that acidic gases likely react with and partition to either crustal particles or hydrometeors enriched with crustal constituents. Concentrations of particulate SO42− show a statistically significant correlation with rain SO42− unlike snow SO42−, which may be related to some combination of the vertical distribution of SO42− (and precursors and the varying degree to which SO42−-enriched particles act as cloud condensation nuclei versus ice nuclei in the region. The coarse : fine aerosol mass ratio was correlated with crustal species concentrations in snow unlike rain, suggestive of a preferential role of coarse particles (mainly dust as ice nuclei in the region. Precipitation NO3− : SO42− ratios exhibit the following features with potential explanations discussed: (i they are higher in precipitation as compared to PM2.5; (ii they exhibit the opposite annual cycle compared to particulate NO3− : SO42− ratios; and (iii they are higher in snow relative to rain during the wintertime. Long-term trend analysis for the monsoon season shows that the NO3− : SO42− ratio in rain increased at the majority of sites due mostly to air pollution regulations of SO42− precursors.

  14. Geographic disparities of asthma prevalence in south-western United States of America

    Directory of Open Access Journals (Sweden)

    Lung-Chang Chien

    2014-11-01

    Full Text Available Asthma is one of the most prevalent chronic diseases in the United States of America (USA, and many of its risk factors have so far been investigated and identified; however, evidence is limited on how spatial disparities impact the disease. The purpose of this study was to provide scientific evidence on the location influence on asthma in the four states of south- western USA (California, Arizona, New Mexico and Texas which, together, include 360 counties. The Behavioral Risk Factor Surveillance System database for these four states covering the period of 2000 to 2011 was used in this analysis, and a Bayesian structured additive regression model was applied to analyse by a geographical information system. After adjusting for individual characteristics, socioeconomic status and health behaviour, this study found higher odds associated with asth- ma and a likely cluster around the Bay Area in California, while lower odds appeared in several counties around the larger cities of Texas, such as Dallas, Houston and San Antonio. The significance map shows 43 of 360 counties (11.9% to be high-risk areas for asthma. The level of geographical disparities demonstrates that the county risk of asthma prevalence varies significantly and can be about 19.9% (95% confidence interval: 15.3-25.8 higher or lower than the overall asthma prevalence. We provide an efficient method to utilise and interpret the existing surveillance data on asthma. Visualisation by maps may help deliver future interventions on targeted areas and vulnerable populations to reduce geographical disparities in the burden of asthma.

  15. Estimation of water requirement per unit carbon fixed by Eucalyptus camaldulensis in semi-arid land of Western Australia

    Institute of Scientific and Technical Information of China (English)

    T. Kojima; Y. Tanaka; S. Katoh; K. Tahara; N. Takahashi; K, Yamada

    2002-01-01

    Afforestation in arid land is a promising method for carbon fixation, but the effective utili-zation of water is highly important and required. Thus, the evaluation of the amount of water perunit carbon fixed with the tree growth is required to minimize the amount of water supplied to theplants. In this research, a tree is regarded as a carbon fixation reactor with inflows of water andnutrients from roots, and CO2 as the carbon source from leaves with outflow of water vapor fromleaves and accumulation in the tree itself. In the process of photosynthesis and respiration nutri-tional elements are dissolved in water flow in trees. They do not flow out by these reactions, butare accumulated in trees. Thus, we have treated the behaviour of nutrients as a marker to evaluatethe water/carbon ratio. Assuming that nutrient concentration is constant in sap, and the differences in the ratios ofnutrient to carbon in living trees and dead (i.e. litter fall, etc.) are negiected, the ratio of the usedwater to fixed carbon is given as the ratio of nutrient to carbon in the tree body divided by the ratioof nutrient to water in sap. However, some nutrients are translocated and concentrated within thetree and some may be discarded through litter fall. Thus it is important to examine which nutrientelement is the most suitable as the tracer. In this paper, the results of the above method applied to Eucalyptus camaldulensis in semi-arid land of Western Australia are shown. The value of water requirement per unit carbon fixationdetermined from potassium balance is between 421 kg-H2O/kg-C for mature trees and 285kg-H2O/k9-C for young trees, while the values from calcium balance are much larger than these.The cause of the discrepancy between these values is discussed based on the measured elementconcentrations in sap and trees and the plant physiology. Finally, the actual average value throughthe life of a tree is suggested to fall between the two values.

  16. Roadmap for sustainable water resources in southwestern North America.

    Science.gov (United States)

    Gleick, Peter H

    2010-12-14

    The management of water resources in arid and semiarid areas has long been a challenge, from ancient Mesopotamia to the modern southwestern United States. As our understanding of the hydrological and climatological cycles has improved, and our ability to manipulate the hydrologic cycle has increased, so too have the challenges associated with managing a limited natural resource for a growing population. Modern civilization has made remarkable progress in water management in the past few centuries. Burgeoning cities now survive in desert regions, relying on a mix of simple and complex technologies and management systems to bring adequate water and remove wastewater. These systems have permitted agricultural production and urban concentrations to expand in regions previously thought to have inadequate moisture. However, evidence is also mounting that our current management and use of water is unsustainable. Physical, economic, and ecological limits constrain the development of new supplies and additional water withdrawals, even in regions not previously thought vulnerable to water constraints. New kinds of limits are forcing water managers and policy makers to rethink previous assumptions about population, technology, regional planning, and forms of development. In addition, new threats, especially the challenges posed by climatic changes, are now apparent. Sustainably managing and using water in arid and semiarid regions such as the southwestern United States will require new thinking about water in an interdisciplinary and integrated way. The good news is that a wide range of options suggest a roadmap for sustainable water management and use in the coming decades. PMID:21149725

  17. Roadmap for sustainable water resources in southwestern North America.

    Science.gov (United States)

    Gleick, Peter H

    2010-12-14

    The management of water resources in arid and semiarid areas has long been a challenge, from ancient Mesopotamia to the modern southwestern United States. As our understanding of the hydrological and climatological cycles has improved, and our ability to manipulate the hydrologic cycle has increased, so too have the challenges associated with managing a limited natural resource for a growing population. Modern civilization has made remarkable progress in water management in the past few centuries. Burgeoning cities now survive in desert regions, relying on a mix of simple and complex technologies and management systems to bring adequate water and remove wastewater. These systems have permitted agricultural production and urban concentrations to expand in regions previously thought to have inadequate moisture. However, evidence is also mounting that our current management and use of water is unsustainable. Physical, economic, and ecological limits constrain the development of new supplies and additional water withdrawals, even in regions not previously thought vulnerable to water constraints. New kinds of limits are forcing water managers and policy makers to rethink previous assumptions about population, technology, regional planning, and forms of development. In addition, new threats, especially the challenges posed by climatic changes, are now apparent. Sustainably managing and using water in arid and semiarid regions such as the southwestern United States will require new thinking about water in an interdisciplinary and integrated way. The good news is that a wide range of options suggest a roadmap for sustainable water management and use in the coming decades.

  18. Changes in vegetation and drainage density as controlling factors in the episodicity of Quaternary sediment flux: southwestern United States and Bolivian Eastern Cordillera

    Science.gov (United States)

    Barnes, J.; Pelletier, J. D.

    2001-12-01

    Piedmont geomorphic surfaces in the southwestern U.S. primarily represent cut-and-fill cycles resulting from variations in sediment supply from adjacent mountain catchments. Although sparse, precise age control supports the hypothesis that sediment supply in the southwestern U.S. can increase by an order of magnitude during Quaternary humid-to-arid transitions recognized in high-resolution paleoclimatic proxies. As an example, this episodicity is quantified with a time series of sediment flux for the central Gila Mountains, southwestern Arizona, where paleosurfaces outcrop in the modern channel bank, permitting an estimate of deposit volume in conjunction with high-resolution photogrammetric DEMs. Age control is provided by a new method of surface exposure dating based on 3D hillslope diffusion adjacent to gullies penetrating the surface. We propose that episodes of piedmont alluviation result from an increase in drainage density resulting from climatically-induced vegetative successions from mature woodland vegetation to desert shrubs that excavate large amounts of hillslope colluvium stored during the previous humid interval. Analogous vegetative shifts occur in the Bolivian Eastern Cordillera (EC). Field observations and analyses of topographic maps and LANDSAT images suggest that the longitudinal profiles of the major rivers of the EC are dominated by an order-of-magnitude increase in Plio-Quaternary hillslope erosion in the elevation zone between approximately 2.5 and 3.5 kilometers above sea level corresponding to glacial-interglacial vegetational successions from Andean forest (glacial) to Paramo grasslands (interglacial). These vegetation changes resulted in rapid fluctuations in drainage density responsible for a large increase in transport rates that alluviated major valleys and enhanced bedrock incision rates downstream. Areas above and below this elevation have perennial grassland and forest, respectively, whose long-term vegetational stability has

  19. Soil Moisture Mapping in an Arid Area Using a Land Unit Area (LUA Sampling Approach and Geostatistical Interpolation Techniques

    Directory of Open Access Journals (Sweden)

    Saeid Gharechelou

    2016-03-01

    Full Text Available Soil moisture (SM plays a key role in many environmental processes and has a high spatial and temporal variability. Collecting sample SM data through field surveys (e.g., for validation of remote sensing-derived products can be very expensive and time consuming if a study area is large, and producing accurate SM maps from the sample point data is a difficult task as well. In this study, geospatial processing techniques are used to combine several geo-environmental layers relevant to SM (soil, geology, rainfall, land cover, etc. into a land unit area (LUA map, which delineates regions with relatively homogeneous geological/geomorphological, land use/land cover, and climate characteristics. This LUA map is used to guide the collection of sample SM data in the field, and the field data is finally spatially interpolated to create a wall-to-wall map of SM in the study area (Garmsar, Iran. The main goal of this research is to create a SM map in an arid area, using a land unit area (LUA approach to obtain the most appropriate sample locations for collecting SM field data. Several environmental GIS layers, which have an impact on SM, were combined to generate a LUA map, and then field surveying was done in each class of the LUA map. A SM map was produced based on LUA, remote sensing data indexes, and spatial interpolation of the field survey sample data. The several interpolation methods (inverse distance weighting, kriging, and co-kriging were evaluated for generating SM maps from the sample data. The produced maps were compared to each other and validated using ground truth data. The results show that the LUA approach is a reasonable method to create the homogenous field to introduce a representative sample for field soil surveying. The geostatistical SM map achieved adequate accuracy; however, trend analysis and distribution of the soil sample point locations within the LUA types should be further investigated to achieve even better results. Co

  20. Post-Closure Challenges of U.S. Department of Energy Sites in Desert Environments of the Southwestern United States - 12095

    International Nuclear Information System (INIS)

    U.S. Department of Energy (DOE) sites located in harsh desert environments of the Four Corners region of the southwestern United States require diligence and continual maintenance to ensure the remediation systems function as designed to protect human health and the environment. The geology and climate of this area create issues that are unique to these sites. Geologic formations contain naturally occurring constituents that are often the same as the residual contaminants remaining from historical milling activities at the sites. Although annual precipitation is low, when precipitation events occur they can be of extreme intensity, resulting in erosion and flooding that can quickly destroy infrastructure and rapidly change site conditions. Winds can cause sand storms and sand mounding that effect site features. These challenging environmental conditions, along with the remote locations of the sites, require active management beyond what was originally envisioned for uranium disposal sites to address concerns in a safe and cost-effective manner. The unique environment of the Four Corners region creates many challenges to the LTSM of LM sites in southwestern United States. The remediation efforts and approaches to infrastructure have to be specifically structured to work in this environment. Often, the systems and structures have to be modified based on lessons learned on how to best adapt to these difficult conditions and remote locations. These sites require continual maintenance and additional efforts compared to many other LM sites. (authors)

  1. Determination of unit nutrient loads for different land uses in wet periods through modelling and optimization for a semi-arid region

    Science.gov (United States)

    Özcan, Zeynep; Kentel, Elçin; Alp, Emre

    2016-09-01

    Diffuse pollution abatement has been a challenge for decision-makers because of the intermittent nature and difficulty of identifying impacts of non-point sources. Depending on the degree of complexity of the system processes and constraints related to time, budget and human resources, variety of tools are used in diffuse pollution management. Decision-makers prefer to use rough estimates that require limited time and budget, in the preliminary assessment of diffuse pollution. The unit pollution load method which is based on the pollution generation rate per unit area and time for a given land use can aid decision-makers in the preliminary assessment of diffuse pollution. In this study, a deterministic distributed watershed model, SWAT is used together with nonlinear optimization models to estimate unit nutrient pollution loads during wet periods for different land use classes for the semi-arid Lake Mogan watershed that is dominated by agricultural activities. Extensive data sets including in-stream water quality and flowrate measurements, meteorological data, land use/land cover (LULC) map developed using remote sensing algorithms, information about agricultural activities, and soil data are used to calibrate and verify the hydraulic and water quality components of SWAT model. Results show that the unit total nitrogen (TN) and total phosphorus (TP) loads (0.46 kg TN/ha/yr and 0.07 kg TP/ha/yr) generated from the watershed during wet periods are very close to the minimum values of the loads specified in the literature and highly depend on the variations in rainfall. Estimated unit nutrient loads both at watershed scale and for different land use classes can be used to assess diffuse pollution control measures for similar regions with semi-arid conditions and heavy agricultural activity.

  2. Productivity and residual benefits of grain legumes to sorghum under semi-arid conditions in south-western Zimbabwe: Unravelling the effects of water and nitrogen using a simulation model

    NARCIS (Netherlands)

    Ncube, B.; Dimes, J.P.; Wijk, van M.T.; Twomlow, S.J.; Giller, K.E.

    2009-01-01

    The APSIM model was used to assess the impact of legumes on sorghum grown in rotation in a nutrient-limited system under dry conditions in south-western Zimbabwe. An experiment was conducted at Lucydale, Matopos Research Station, between 2002 and 2005. The model was used to simulate soil and plant r

  3. Inventories and mobilization of unsaturated zone sulfate, fluoride, and chloride related to land use change in semiarid regions, southwestern United States and Australia

    Science.gov (United States)

    Scanlon, B.R.; Stonestrom, D.A.; Reedy, R.C.; Leaney, F.W.; Gates, J.; Cresswell, R.G.

    2009-01-01

    Unsaturated zone salt reservoirs are potentially mobilized by increased groundwater recharge as semiarid lands are cultivated. This study explores the amounts of pore water sulfate and fluoride relative to chloride in unsaturated zone profiles, evaluates their sources, estimates mobilization due to past land use change, and assesses the impacts on groundwater quality. Inventories of water-extractable chloride, sulfate, and fluoride were determined from borehole samples of soils and sediments collected beneath natural ecosystems (N = 4), nonirrigated ("rain-fed") croplands (N = 18), and irrigated croplands (N = 6) in the southwestern United States and in the Murray Basin, Australia. Natural ecosystems contain generally large sulfate inventories (7800-120,000 kg/ha) and lower fluoride inventories (630-3900 kg/ha) relative to chloride inventories (6600-41,000 kg/ha). Order-of-magnitude higher chloride concentrations in precipitation and generally longer accumulation times result in much larger chloride inventories in the Murray Basin than in the southwestern United States. Atmospheric deposition during the current dry interglacial climatic regime accounts for most of the measured sulfate in both U.S. and Australian regions. Fluoride inventories are greater than can be accounted for by atmospheric deposition in most cases, suggesting that fluoride may accumulate across glacial/ interglacial climatic cycles. Chemical modeling indicates that fluorite controls fluoride mobility and suggests that water-extractable fluoride may include some fluoride from mineral dissolution. Increased groundwater drainage/recharge following land use change readily mobilized chloride. Sulfate displacement fronts matched or lagged chloride fronts by up to 4 m. In contrast, fluoride mobilization was minimal in all regions. Understanding linkages between salt inventories, increased recharge, and groundwater quality is important for quantifying impacts of anthropogenic activities on groundwater

  4. Validate Tomography with Broadband Waveform Modeling: An Example at La Ristra Transect in the Southwestern United States

    Science.gov (United States)

    Song, T. A.; Helmberger, D. V.

    2005-12-01

    Travel time tomography has been the main tool for seismologists in developing mantle structure and studying regional tectonics. Standard practice for geodynamists is to convert the velocity anomalies into temperature and density and fit geophysical observables such as topography and gravity. However, tomographic models produced by smooth, damped inversions usually underestimate the amplitude and sharpness of the velocity structure. To validate these tomographic models, it is important to propagate seismic waves through them and compare synthetic waveforms with obvervations directly, which enable us to enhance and sharpen these models. Here we illustrate an example using the Rio Grande Rift PASSCAL observations in the southwestern US. The La Ristra passive experiment was designed to cross the Rio Grande Rift system and study the tranition in mantle structure from Great Plain to Colorado Plateau (e.g. Gao et al. 2004; West et al. 2004, Wilson et al. 2005). Ray-based body wave travel time tomography (Gao et al. 2004) indicated a linear, south-east dipping slab-like fast velocity anomaly under the western edge of the Great Plain. They interpreted it as a downwelling lithosphere produced by a small scale convection. We take advantages of the dense linear array and examine data from two deep events in south America. After deconvolving the source wavelet from the raw data, deconvolved waveforms of both events consistently show that P and S waveforms are severely distorted at stations across the slab boundary by a factor of 2-3. The waveform amplitude also diminishs in proportional to the wavefrom broadening. The waveform shape becomes simple again for stations near the center of the rift. We implement the tomography model into the 2-D finite difference scheme (Vidale, 1985; Helmberger and Vidale, 1988). Preliminary result shows that amplifying the tomography model by a factor of 3 starts to produce the waveform distortions observed.

  5. Genetic risk for recombinant 8 syndrome and the transmission rate of balanced inversion 8 in the Hispanic population of the southwestern United States.

    Science.gov (United States)

    Smith, A C; Spuhler, K; Williams, T M; McConnell, T; Sujansky, E; Robinson, A

    1987-12-01

    A rec(8) dup(q) syndrome, secondary to a pericentric inversion--inv(8)(p23q22)--has been identified in 26 probands from Hispanic kindreds in the southwestern United States. The clinical phenotype of the Hispanic rec(8) syndrome includes a dysmorphic facies, cardiovascular and urinary-tract malformations, and mental retardation. Segregation analysis utilizing pedigree and cytogenetic data from 31 kindreds including five additional kindreds from additional sources has provided computation of genetic risks for counseling. An inv(8) carrier parent has a 6.2% risk of having a rec(8) child. The transmission rate of the inv(8) was significantly higher for inv(8) carrier mothers (59%) than for carrier fathers (42%). The combined transmission rate for both sexes was 53%. Risk for spontaneous abortion or stillbirth (11.3%) was not higher than the general population frequency of 13%-15%. It is significant that all kindreds identified to date are of Hispanic background with ancestors traced to the southern Colorado/northern New Mexico region. By means of extended pedigree information, three independently ascertained kindreds have been linked through common ancestry 4 generations in ascendance. The Hispanic background, geographic localization, and common ancestry in three kindreds suggest a single founder of the Hispanic inv(8) in the Southwest.

  6. Natural history, ecology, and conservation of the genus Polyphylla Harris, 1841. 1. New species from the southwestern United States and Baja California, Mexico, with notes on distribution and synonymy (Coleoptera: Scarabaeidae: Melolonthinae)

    OpenAIRE

    La Rue, Delbert A.

    2016-01-01

    Four new species of the genus Polyphylla Harris (Coleoptera: Scarabaeidae: Melolonthinae) from the southwestern United States and Baja California, Mexico, are described and illustrated: Polyphylla anivallis, P. koso, P. morroensis, and P. socorriana. Two nomenclatural changes are proposed: Polyphylla ratcliffei Young is placed into synonymy with P. avittata Hardy and Andrews, new synonymy; P. uteana Tanner is removed from synonymy and reinstated as a valid species, reinstated status. The fema...

  7. Traces of the crustal units and the upper mantle structure in the southwestern part of the East European Craton

    Directory of Open Access Journals (Sweden)

    I. Janutyte

    2014-04-01

    Full Text Available The presented study is a part of the passive seismic experiment PASSEQ 2006–2008 which took place around the Trans-European Suture Zone (TESZ from May 2006 to June 2008. The dataset of 4195 manually picked arrivals of teleseismic P waves of 101 earthquakes (EQs recorded in the PASSEQ seismic stations deployed to the east of the TESZ was inverted using the non-linear teleseismic tomography algorithm TELINV. Two 3-D crustal models were used to estimate the crustal travel time (TT corrections. As a result, we obtained a model of P wave velocity variations in the upper mantle beneath the TESZ and the EEC. In the study area beneath the craton we observed 5 to 6.5% higher and beneath the TESZ about 4% lower seismic velocities compared to the IASP91 velocity model. We found the seismic lithosphere-asthenosphere boundary (LAB beneath the TESZ at a depth of about 180 km, while we observed no seismic LAB beneath the EEC. The inversion results obtained with the real and the synthetic datasets indicated a ramp shape of the LAB in the northern TESZ where we observed values of seismic velocities close to those of the craton down to about 150 km. The lithosphere thickness in the EEC increases going from the TESZ to the NE from about 180 km beneath Poland to 300 km or more beneath Lithuania. Moreover, in western Lithuania we possibly found an upper mantle dome. In our results the crustal units are not well resolved. There are no clear indications of the features in the upper mantle which could be related with the crustal units in the study area. On the other hand, at a depth of 120–150 km we possibly found a trace of a boundary of proposed palaeosubduction zone between the East Lithuanian Domain (EL and the West Lithuanian Granulite Domain (WLG. Also, in our results we may have identified two anorogenic granitoid plutons.

  8. Parasitismo natural em moscas-das-frutas (Diptera: Tephritidae no semiárido do sudoeste da Bahia, Brasil Natural parasitism in fruit-flies in the fruticulture area of anagé, semi-arid of southwestern Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo Falcão de Sá

    2012-12-01

    Full Text Available Parasitoides são importantes agentes de controle natural de tefritídeos, e os conhecimentos sobre as relações tritróficas podem subsidiar o manejo destas pragas. Este trabalho objetivou estimar índices de parasitismo em moscas-das-frutas, em 21 espécies vegetais, e identificar as espécies de parasitoides associados, nas condições do semiárido do sudoeste da Bahia. Oito hospedeiros apresentaram infestação por Anastrepha spp. e, destes, em quatro, ocorreu parasitismo superior a 20,0%, sendo: 20,8% (Ziziphus joazeiro L.; 21,3% (Spondias tuberosa L.; 32,4% (Spondias purpurea L. e 57,1% (Malpighia emarginata L.. Os parasitoides coletados pertencem à família Braconidae, sendo 89% de Doryctobracon areolatus e 11% de Asobara anastrephae.Parasitoids are important natural control agents of tephritids and knowledge about the tritrophic relationships can support the management of these pests. This study aimed to estimate of parasitism indexes in fruit flies in 21 plant species and identify the species of parasitoids associated, in semiarid conditions of Southwestern Bahia. Eight hosts showed infestation by Anastrepha spp. and, of these, four occurred parasitism above 20.0%, of which: 20.8% (Ziziphus joazeiro L.; 21.3% (Spondias tuberosa L.; 32.4% (Spondias purpurea L. and 57.1% (Malpighia emarginata L.. The collected parasitoids belong to the Braconidae family, 89% of Doryctobracon areolatus and 11% of Asobara anastrephae.

  9. Application of a hydrological model in a data-poor arid region catchment: a case study of Wadi Ham, United Arab Emirates

    OpenAIRE

    Al Mulla , Mohamed Mustafa

    2005-01-01

    Many arid region Wadi catchments are facing increasing water scarcity due to the unsustainable human practises such as the over expansion of irrigated agriculture and over exploitation of their groundwater aquifers. The “Soil and Water Assessment Tool” (SWAT) model, which is a comprehensive conceptual, semi-distributed watershed scale model, was selected after a review of the hydrological processes occurring in arid region catchments to simulate the hydrological processes of...

  10. Keeping Sediment and Nutrients out of Streams in Arid/Semi-Arid Regions: Application of Low Impact Development/Green Infrastructure Practices

    Science.gov (United States)

    Yongping, Yuan

    2015-04-01

    Climatic and hydrological characteristics in the arid/semi-arid areas create unique challenges to soil, water and biodiversity conservation. These areas are environmentally sensitive, but very valuable for the ecosystems services they provide to society. Some of these areas are experiencing the fastest urbanization and now face multiple water resource challenges. Low Impact Development (LID)/Green Infrastructure (GI) practices are increasingly popular for reducing stormwater and nonpoint source pollution in many regions around the world. However, streamflow in the arid/semi-arid regions is largely dependent on seasonal, short term, and high intensity rainfall events. LID has not been very common in the arid/semi-arid regions due to a lack of performance evaluation, as well as the perception that LID may not be very useful for regions with little annual precipitation. This study focused on investigating the hydrologic and pollutant removal performance of LID/GI systems in arid/semi-arid climates. Ten types of practices were found in use in the Western/Southwestern U.S.: rainwater harvest systems, detention ponds, retention ponds, bioretention, media filters, porous pavements, vegetated swales/buffer/strips, green roofs, infiltration trenches, and integrated LIDs. This study compared the performance of these practices in terms of their effectiveness at pollutant removal and cost-effectiveness. This analysis provides insight into the future implementation of LID/GI in the arid/semi-arid areas. Key words: LID/GI, arid/semi-arid, effectiveness of pollutant removal, cost-effectiveness analysis

  11. A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra

    Science.gov (United States)

    McMillian, W. Wallace; Strow, L. Larrabee; Revercomb, H.; Knuteson, R.; Thompson, A.

    2003-01-01

    This final report summarizes all research activities and publications undertaken as part of NASA Atmospheric Chemistry and Modeling Analysis Program (ACMAP) Grant NAG-1-2022, 'A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra'. Major project accomplishments include: (1) analysis of more than 300,000 AERI spectra from the ARM SGP site yielding a 5-year (1998-2002) timeseries of CO retrievals from the Lamont, OK AERI; (2) development of a prototype CO profile retrieval algorithm for AERI spectra; (3) validation and publication of the first CO retrievals from the Scanning High-resolution Interferometer Sounder (SHIS); and (4) development of a prototype AERI tropospheric O3 retrieval algorithm. Compilation and publication of the 5-year Lamont, OK timeseries is underway including a new collaboration with scientists at the Lawrence Berkeley National Laboratory. Public access to this data will be provided upon article submission. A comprehensive CO analysis of the archive of HIS spectra of remains as the only originally proposed activity with little progress. The greatest challenge faced in this project was motivating the University of Wisconsin Co-Investigators to deliver their archived HIS and AERIOO data along with the requisite temperature and water vapor profiles in a timely manner. Part of the supplied HIS dataset from ASHOE may be analyzed as part of a Master s Thesis under a separate project. Our success with the SAFARI 2000 SHIS CO analysis demonstrates the utility of such aircraft remote sensing data given the proper support from the instrument investigators. In addition to the PI and Co-I s, personnel involved in this CO climatology project include one Post Doctoral Fellow, one Research Scientist, two graduate students, and two undergraduate students. A total of fifteen presentations regarding research related to this

  12. Plant distributions in the southwestern United States; a scenario assessment of the modern-day and future distribution ranges of 166 Species

    Science.gov (United States)

    Thomas, Kathryn A.; Guertin, Patricia P.; Gass, Leila

    2012-01-01

    The authors developed spatial models of the predicted modern-day suitable habitat (SH) of 166 dominant and indicator plant species of the southwestern United States (herein referred to as the Southwest) and then conducted a coarse assessment of potential future changes in the distribution of their suitable habitat under three climate-change scenarios for two time periods. We used Maxent-based spatial modeling to predict the modern-day and future scenarios of SH for each species in an over 342-million-acre area encompassing all or parts of six states in the Southwest--Arizona, California, Colorado, Nevada, New Mexico, and Utah. Modern-day SH models were predicted by our using 26 annual and monthly average temperature and precipitation variables, averaged for the years 1971-2000. Future SH models were predicted for each species by our using six climate models based on application of the average of 16 General Circulation Models to Intergovernmental Panel on Climate Change emission scenarios B1, A1B, and A2 for two time periods, 2040 to 2069 and 2070 and 2100, referred to respectively as the 2050 and 2100 time periods. The assessment examined each species' vulnerability to loss of modern-day SH under future climate scenarios, potential to gain SH under future climate scenarios, and each species' estimated risk as a function of both vulnerability and potential gains. All 166 species were predicted to lose modern-day SH in the future climate change scenarios. In the 2050 time period, nearly 30 percent of the species lost 75 percent or more of their modern-day suitable habitat, 21 species gained more new SH than their modern-day SH, and 30 species gained less new SH than 25 percent of their modern-day SH. In the 2100 time period, nearly half of the species lost 75 percent or more of their modern-day SH, 28 species gained more new SH than their modern-day SH, and 34 gained less new SH than 25 percent of their modern-day SH. Using nine risk categories we found only two

  13. Rapid warming and drought negatively impact population size and reproductive dynamics of an avian predator in the arid southwest.

    Science.gov (United States)

    Cruz-McDonnell, Kirsten K; Wolf, Blair O

    2016-01-01

    Avian communities of arid ecosystems may be particularly vulnerable to global climate change due to the magnitude of projected change for desert regions and the inherent challenges for species residing in resource limited ecosystems. How arid-zone birds will be affected by rapid increases in air temperature and increased drought frequency and severity is poorly understood because avian responses to climate change have primarily been studied in the relatively mesic northern temperate regions. We studied the effects of increasing air temperature and aridity on a Burrowing Owl (Athene cunicularia) population in the southwestern United States from 1998 to 2013. Over 16 years, the breeding population declined 98.1%, from 52 pairs to 1 pair, and nest success and fledgling output also declined significantly. These trends were strongly associated with the combined effects of decreased precipitation and increased air temperature. Arrival on the breeding grounds, pair formation, nest initiation, and hatch dates all showed significant delays ranging from 9.4 to 25.1 days over 9 years, which have negative effects on reproduction. Adult and juvenile body mass decreased significantly over time, with a loss of 7.9% mass in adult males and 10.9% mass in adult females over 16 years, and a loss of 20.0% mass in nestlings over 8 years. Taken together, these population and reproductive trends have serious implications for local population persistence. The southwestern United States has been identified as a climate change hotspot, with projections of warmer temperatures, less winter precipitation, and an increase in frequency and severity of extreme events including drought and heat waves. An increasingly warm and dry climate may contribute to this species' decline and may already be a driving force of their apparent decline in the desert southwest. PMID:26367541

  14. Evidence of Urban-Induced Precipitation Variability in Arid Climate Regimes

    Science.gov (United States)

    Shepherd, J. Marshall

    2005-01-01

    Water is essential to life in the Earth system. The water cycle components that sustain life are becoming more scarce and polluted. The most recent (1999-2004) drought experienced in the southwestern United States is the seventh worst in the approximately 500-year proxy tree-ring record. As a result, many regions contemplated drought emergencies in which severe water restrictions are implemented. Though larger weather and climate processes likely control drought processes, there is increasing evidence that anthropogenic or human-related activities can significantly alter precipitation processes. Urbanization is an example of anthropogenic forcing. Recent studies continue to provide evidence that urban environments can modify or induce precipitation under a specific set of conditions. Arid and semi-arid regions of the southwestern United States and other parts of the world are rapidly developing and placing greater demands on the environmental system. In the past fifty years, Phoenix has expanded from a predominantly agricultural center to an urbanized region with extent 700 percent larger than its size in the middle of the twentieth century. Riyadh's population grew from about a half million people in 1972 to almost two million by 2000. Saudi Arabia experienced urbanization later than many other countries; in the early 1970s its urban-rural ratio was still about 1:3. By 1990 the ratio had reversed to about 3:l. In the mid-1970s Riyadh's population was increasing by about 10 percent a year. Irrigation also significantly increased between 1972 and 1990 southeast of Riyadh. The study employs a 108-year precipitation historical data record, global climate observing network observations and satellite data to identify possible anomalies in rainfall in and around two major arid urban areas, Phoenix, Arizona and Riyadh, Saudi Arabia. It provides statistically sound evidence that rainfall distribution and magnitude is statistically different in post-urban than in pre

  15. Number of winter rainy days reconstructed from southwestern tree rings

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, C. [NOAA Paleoclimatology Program, Boulder, CO (United States); Meko, D. [Univ. of Arizona, Tucson, AZ (United States)

    1997-11-01

    The objective of this paper is to explore the usefulness of tree-ring data for quantifying the temporal variability of winter rainy-day frequency over the past three centuries in the southwestern United States. The climatological variable, number of rainy days, has not previously been used in dendroclimatic reconstructions. It is reasonable to expect that the number of rainy days might be more strongly related than total precipitation to seasonally aggregated moisture conditions sensed by trees, especially in areas where rainfall from infrequent, heavy storms may run off before much moisture is absorbed into the soil. This study uses a network of tree-ring chronologies with a common time period 1702-1983 to reconstruct number of winter rainy days for a sub-region within the Southwest. The variance in the rainy day record explained by the tree-ring chronologies exceeds the 60% variance commonly yielded from arid-site trees in western North America. Calibration and verification statistics are highly significant, and a comparison with an independent gauge record helps validate the reconstruction. Conceptually and by the objective criterion of percent variance explained, number of rainy days appears, for this region, to be superior to total winter precipitation as a climatic variable for tree-ring reconstruction. 17 refs., 4 figs.

  16. Mining the Agave Microbiome for adaptions to arid environments

    Energy Technology Data Exchange (ETDEWEB)

    Coleman-Derr, Devin; Wojke, Tanja; North, Gretchen; Partida-Martinez, Laila; DeAngeli, Kristen; Clingenpeel, Scott; Gross, Stephen; Tringe, Susannah; Visel, Axel

    2013-03-25

    A major challenge facing the biofuels industry is the identification of high-yield plant feedstocks that can be cultivated with minimal resource inputs without competing for land and water supplies with existing food crops. Recent research has demonstrated that the Agave plant, cultivated in Mexico and Southwestern United States for the production of fiber and alcohol, meets these criteria1. Agaves grow on non-arable rocky soils in regions characterized by prolonged drought and extreme temperatures, due in part to physiological adaptions that prevent excess water-loss in arid environments2. Plant-microbial symbioses can play a role in helping plants adapt to heat and drought stress, increasing the accessibility of soil nutrients, or compete with plant pathogens3. Whether agaves have similar beneficial microbe interactions in their native environment is unknown. We aim to provide a comprehensive characterization of the Agave microbiome, with the goal of identifying specific community members that may contribute to Agave biotic and abiotic stress tolerance

  17. Environmental Management Audit: Southwestern Power Administration (Southwestern)

    International Nuclear Information System (INIS)

    This report documents the results of the Environmental Management Audit completed for the Southwestern Power Administration. During this Audit, activities and records were reviewed and personnel interviewed. The onsite portion of the Southwestern Audit was conducted from November 30 through December 11, 1992, by the US Department of Energy's Office of Environmental Audit (EH-24). EH-24 carries out independent assessments of Department of Energy (DOE) facilities and activities as part of the Assistant Secretary's Environmental Audit Program. This program is designed to evaluate the status of DOE facilities/activities regarding compliance with laws, regulations, DOE Orders, formal written procedures, compliance agreements, and Best Management Practices (BMPs). This internal oversight function plays an important role in improving the compliance status of DOE operations. The Environmental Management Audit stresses DOE's policy that it is the responsibility of line management to conduct operations in an environmentally sound and safe manner. The Environmental Management Audit focuses on management systems and programs, whereas the Environmental Baseline Audit conducted in March 1991 focused on specific compliance issues. The scope of the Southwestern Environmental Management Audit included a review of all systems and functions necessary for effective environmental management. Specific areas of review included: Organizational Structure; Environmental Commitment; Environmental Protection Programs; Formality of Environmental Programs; Internal and External Communication; Staff Resources, Training, and Development; and Program Evaluation, Reporting, and Corrective Action

  18. Physical and chemical parameters affecting transport of 137Cs in arid watersheds

    International Nuclear Information System (INIS)

    The occurrence and amount of fallout 137Cs were determined in 12 watersheds in the arid southwestern United States. The factors believed to influence the distribution of 137Cs in the watershed soils and in the reservoir sediments were investigated by using stepwise regression techniques. Seventeen parameters, in the case of soils, and 21 parameters, in the case of sediments, were used in the study. Ninety percent of the variation in the 137Cs content of soils, per unit weight, could be predicted in terms of the percentage of soil nitrogen, the R factor (rainfall intensity) of the universal soil loss equation, the percentage of sand in the soils, and the soil cation exchange capacity. Also, 90% of the variation in the content of 137Cs in the watershed soils, per unit area, could be predicted in terms of the fallout intensity, the percentages of silt and clay, and the cation exchange capacity. For reservoir sediments the equivalent predictors of 137Cs accumulation in the sediment profile, per unit weight, were the soil cation exchange capacity, the January-March average precipitation, and the soil contents of total P and N. The distribution of 137Cs in sediments per unit area was similarly predicted by watershed area, percentage of total soil C, reservoir surface area, areal concentration of 137Cs in the watershed soils, and soil organic matter

  19. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 2: Crater Size-frequency Distribution Curves and Geomorphic Unit Ages

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    In assessing the relative ages of the geomorphic/geologic units, crater counts of the entire unit or nearly the entire unit were made and summed in order to get a more accurate value than obtainable by counts of isolated sections of each unit. Cumulative size-frequency counts show some interesting relationships. Most of the units show two distinct crater populations with a flattening out of the distribution curve at and below 10 km diameter craters. Above this crater size the curves for the different units diverge most notably. In general, the variance may reflect the relative ages of these units. At times, however, in the larger crater size range, these curves can overlap and cross on another. Also the error bars at these larger sizes are broader (and thus more suspect), since counts of larger craters show more scatter, whereas the unit areas remain constant. Occasional clusters of relatively large craters within a given unit, particularly one of limited areal extent, can affect the curve so that the unit might seem to be older than units which it overlies or cuts.

  20. Ecotonal Control on Vadose-Zone Fluxes in Arid Regions Over Very Long Time Scales

    Science.gov (United States)

    Phillips, F. M.; Walvoord, M. A.; Sandvig, R.

    2003-12-01

    Recent studies indicate that vegetation plays an important role in regulating recharge in semiarid and arid basins over very long time scales. Several lines of evidence from desert floor environments in the southwestern United States suggest that vegetation has established essentially permanent upward hydraulic gradients, effectively precluding diffuse recharge since the transition from woodland to xeric scrub in the early Holocene. However, less xeric vegetation (such as the pygmy piñon and juniper forest) may support significant diffuse recharge. We show comparative water potential and porewater chemistry profiles collected from various vegetation communities in the Chihuahuan Desert of west Texas. The modeled soil water (vapor and liquid) flux regimes illustrate a conversion from substantial downward fluxes under the mixed woodland to upward fluxes under grassland and xeric scrub. Model results also indicated a trend in increasing drying front propagation depth from the grassland to recently-encroached xeric scrub to well-established xeric scrub. Drying fronts are the result of upward soil water fluxes initiated up to 16 thousand years ago in the xeric scrub community. In contrast, the nearby woodland community supports active, and likely episodic, recharge on the order of 5 to 15 mm yr-1. The mechanism by which some vegetation takes up essentially all seasonally available moisture within the root zone, preventing downward soil water fluxes for periods of thousands of years, but adjacent vegetation communities regularly permit downward fluxes, remains to be determined. Nevertheless, these results suggest that understanding the relation between vegetation community and vadose-zone hydrological processes may be the most profitable avenue toward quantifying diffuse groundwater recharge. We hypothesize that vegetation type may be a reasonable proxy for estimating recharge in semiarid and arid basins. Ongoing research is intended to test the hypothesis of ecotonal

  1. Diagnosis of GLDAS LSM based aridity index and dryland identification for socioeconomic aspect of water resources management

    Science.gov (United States)

    Ghazanfari, S.; Pande, S.; Hashemy, M.; Naseri M., M.

    2012-04-01

    for NOAH and MOSAIC. The VIC aridity index displays a pattern most closely resembling that of UNEP though all LSM based indices isolate dominant dryland areas, correctly. The UNEP classification identifies some parts of south central Africa, southeast United States and eastern India as drier than all LSMs. NOAH and MOSAIC categorize parts of SouthWestern Africa drier than the other two classifications, while all LSMs classify parts of central India wetter than the UNEP classification. We find long term average NDVI values showing vegetation cover in areas that UNEP classifies drier than other three LSMs. Finally, based on unsupervised clustering of global land surface based on long term mean temperature and precipitation, soil texture and land slope, areas classified as dry by UNEP but wet by LSMs have relatively wet characteristics while areas classified as wet by UNEP but dry by LSMs have dry characteristics. We conclude that LSM based aridity index identifies dryland areas other than UNEP aridity index since the former also incorporates the role of vegetation and soil in partitioning of precipitation into evaporation, runoff and infiltration.

  2. Waste biorefinery in arid/semi-arid regions.

    Science.gov (United States)

    Bastidas-Oyanedel, Juan-Rodrigo; Fang, Chuanji; Almardeai, Saleha; Javid, Usama; Yousuf, Ahasa; Schmidt, Jens Ejbye

    2016-09-01

    The utilization of waste biorefineries in arid/semi-arid regions is advisable due to the reduced sustainable resources in arid/semi-arid regions, e.g. fresh water and biomass. This review focuses on biomass residues available in arid/semi-arid regions, palm trees residues, seawater biomass based residues (coastal arid/semi-arid regions), and the organic fraction of municipal solid waste. The present review aims to describe and discuss the availability of these waste biomasses, their conversion to value chemicals by waste biorefinery processes. For the case of seawater biomass based residues it was reviewed and advise the use of seawater in the biorefinery processes, in order to decrease the use of fresh water. PMID:27072789

  3. Evaluation of an extreme-condition-inverse calibration remote sensing model for mapping energy balance fluxes in arid riparian areas

    Science.gov (United States)

    Hong, S.-H.; Hendrickx, J. M. H.; Kleissl, J.; Allen, R. G.; Bastiaanssen, W. G. M.; Scott, R. L.; Steinwand, A. L.

    2014-12-01

    Accurate information on the distribution of the surface energy balance components in arid riparian areas is needed for sustainable management of water resources as well as for a better understanding of water and heat exchange processes between the land surface and the atmosphere. Since the spatial and temporal distributions of these fluxes over large areas are difficult to determine from ground measurements alone, their prediction from remote sensing data is very attractive as it enables large area coverage and a high repetition rate. In this study the Surface Energy Balance Algorithm for Land (SEBAL) was used to estimate all the energy balance components in the arid riparian areas of the Middle Rio Grande Basin (New Mexico), San Pedro Basin (Arizona), and Owens Valley (California). We compare instantaneous and daily SEBAL fluxes derived from Landsat TM images to surface-based measurements with eddy covariance flux towers. This study presents evidence that SEBAL yields reliable estimates for actual evapotranspiration rates in riparian areas of the southwestern United States. The great strength of the SEBAL method is its internal calibration procedure that eliminates most of the bias in latent heat flux at the expense of increased bias in sensible heat flux.

  4. Evaluation of an extreme-condition-inverse calibration remote sensing model for mapping energy balance fluxes in arid riparian areas

    Directory of Open Access Journals (Sweden)

    S.-H. Hong

    2014-12-01

    Full Text Available Accurate information on the distribution of the surface energy balance components in arid riparian areas is needed for sustainable management of water resources as well as for a better understanding of water and heat exchange processes between the land surface and the atmosphere. Since the spatial and temporal distributions of these fluxes over large areas are difficult to determine from ground measurements alone, their prediction from remote sensing data is very attractive as it enables large area coverage and a high repetition rate. In this study the Surface Energy Balance Algorithm for Land (SEBAL was used to estimate all the energy balance components in the arid riparian areas of the Middle Rio Grande Basin (New Mexico, San Pedro Basin (Arizona, and Owens Valley (California. We compare instantaneous and daily SEBAL fluxes derived from Landsat TM images to surface-based measurements with eddy covariance flux towers. This study presents evidence that SEBAL yields reliable estimates for actual evapotranspiration rates in riparian areas of the southwestern United States. The great strength of the SEBAL method is its internal calibration procedure that eliminates most of the bias in latent heat flux at the expense of increased bias in sensible heat flux.

  5. Effects of Agriculture and Urbanization on Quality of Shallow Ground Water in the Arid to Semiarid Western United States, 1993-2004

    Science.gov (United States)

    Paul, Angela P.; Seiler, Ralph L.; Rowe, Timothy G.; Rosen, Michael R.

    2007-01-01

    Within the Western United States, agricultural and rural lands are being developed into commercial and residential areas. With changes in land use and increasing population, greater demands are placed on water resources for agricultural, industrial, and domestic supplies. Many areas in the Western United States rely exclusively on ground water as their source of drinking water. Areas that use surface-water resources often need to supplement this supply with ground water. Generally, shallow ground water is susceptible to fluctuating water quality within relatively short time scales and therefore can be used as an indicator of land-use stresses that may, in time, affect deep aquifer systems. This regional study examines data on shallow ground-water quality collected from 1993 to 2004 from 273 agricultural and 181 urban wells from 7 U.S. Geological Survey National Water-Quality Assessment study units in Arizona, California, Nevada, New Mexico, south-central Colorado, and Utah. This report determines important influences that land-use practices may have on the quality of recently recharged ground water, which may ultimately affect deep water supplies within the region. The results of this investigation show that nitrate, the principal species of nitrogen present in ground water, exceeds the U.S. Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 10 milligrams per liter in water from more than 25 percent of agricultural wells and 10 percent of urban wells. In agricultural areas, the probability of exceeding the USEPA MCL for nitrate is influenced primarily by three factors: fertilizer use, irrigation, and aquifer oxidation-reduction (redox) conditions. At the study-unit level, differences in nutrient concentrations between agricultural and urban land use likely are influenced by ground-water redox conditions within respective aquifer systems. The most commonly detected pesticides belonged to the triazine, urea, amide, and carbamate classes. The

  6. Study on climate change in Southwestern China

    International Nuclear Information System (INIS)

    Nominated by Chinese Academy of Sciences as an outstanding Ph.D. thesis. Offers a needed exploration of the temporal and spatial pattern of climate change in southwestern China. Explores the action mechanism among the large-scale atmospheric circulation system, the complicated topography, human activities and regional climate changes. Analyzes the response of glaciers to climate change from the aspects of morphology of the glacier, glacial mass balance and the process of hydrology. This thesis confirms many changes, including sharp temperature rise, interannual variability of precipitation, extreme climate events and significant decreases of sunshine duration and wind speed in southwestern China, and systemically explores the action mechanism between large-scale atmospheric circulation systems, the complicated topography, human activities and regional climate changes. This study also analyzes the response of glaciers to climate change so that on the one hand it clearly reflects the relationship between glacier morphologic changes and climate change; on the other, it reveals the mechanism of action of climate warming as a balance between energy and matter. The achievements of this study reflect a significant contribution to the body of research on the response of climate in cold regions, glaciers and human activities to a global change against the background of the typical monsoon climate, and have provided scientific basis for predictions, countermeasures against disasters from extreme weather, utilization of water and the establishment of counterplans to slow and adapt to climate change. Zongxing Li works at the Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, China.

  7. Study on climate change in Southwestern China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zongxing

    2015-03-01

    Nominated by Chinese Academy of Sciences as an outstanding Ph.D. thesis. Offers a needed exploration of the temporal and spatial pattern of climate change in southwestern China. Explores the action mechanism among the large-scale atmospheric circulation system, the complicated topography, human activities and regional climate changes. Analyzes the response of glaciers to climate change from the aspects of morphology of the glacier, glacial mass balance and the process of hydrology. This thesis confirms many changes, including sharp temperature rise, interannual variability of precipitation, extreme climate events and significant decreases of sunshine duration and wind speed in southwestern China, and systemically explores the action mechanism between large-scale atmospheric circulation systems, the complicated topography, human activities and regional climate changes. This study also analyzes the response of glaciers to climate change so that on the one hand it clearly reflects the relationship between glacier morphologic changes and climate change; on the other, it reveals the mechanism of action of climate warming as a balance between energy and matter. The achievements of this study reflect a significant contribution to the body of research on the response of climate in cold regions, glaciers and human activities to a global change against the background of the typical monsoon climate, and have provided scientific basis for predictions, countermeasures against disasters from extreme weather, utilization of water and the establishment of counterplans to slow and adapt to climate change. Zongxing Li works at the Cold and Arid Region Environmental and Engineering Research Institute, Chinese Academy of Sciences, China.

  8. Three Millennia of Southwestern North American Dustiness and Future Implications.

    Science.gov (United States)

    Routson, Cody C; Overpeck, Jonathan T; Woodhouse, Connie A; Kenney, William F

    2016-01-01

    Two sediment records of dust deposition from Fish Lake, in southern Colorado, offer a new perspective on southwest United States (Southwest) aridity and dustiness over the last ~3000 years. Micro scanning X-ray fluorescence and grain size analysis provide separate measures of wind-deposited dust in the lake sediment. Together these new records confirm anomalous dustiness in the 19th and 20th centuries, associated with recent land disturbance, drought, and livestock grazing. Before significant anthropogenic influences, changes in drought frequency and aridity also generated atmospheric dust loading. Medieval times were associated with high levels of dustiness, coincident with widespread aridity. These records indicate the Southwest is naturally prone to dustiness. As global and regional temperatures rise and the Southwest shifts toward a more arid landscape, the Southwest will likely become dustier, driving negative impacts on snowpack and water availability, as well as human health.

  9. Three Millennia of Southwestern North American Dustiness and Future Implications.

    Science.gov (United States)

    Routson, Cody C; Overpeck, Jonathan T; Woodhouse, Connie A; Kenney, William F

    2016-01-01

    Two sediment records of dust deposition from Fish Lake, in southern Colorado, offer a new perspective on southwest United States (Southwest) aridity and dustiness over the last ~3000 years. Micro scanning X-ray fluorescence and grain size analysis provide separate measures of wind-deposited dust in the lake sediment. Together these new records confirm anomalous dustiness in the 19th and 20th centuries, associated with recent land disturbance, drought, and livestock grazing. Before significant anthropogenic influences, changes in drought frequency and aridity also generated atmospheric dust loading. Medieval times were associated with high levels of dustiness, coincident with widespread aridity. These records indicate the Southwest is naturally prone to dustiness. As global and regional temperatures rise and the Southwest shifts toward a more arid landscape, the Southwest will likely become dustier, driving negative impacts on snowpack and water availability, as well as human health. PMID:26886350

  10. CHARACTERISTICS OF ARIDITY CONDITIONS IN SOUTH DOBRUDJA

    Directory of Open Access Journals (Sweden)

    A. TISCOVSCHI

    2013-04-01

    Full Text Available Characteristics of Aridity Conditions in South Dobrudja. For most people, the arid and semi-arid lands are those where precipitation is low (less than 200 mm per year, and yet enough for supplying streams capable of temporarily carrying the debris resulted from weathering, but insufficient for encouraging the development of a vegetal cover meant to protect the soil blanket against eroding agents. The drought is a major and permanent climatic risk for the Dobrudja territory as a whole and for South Dobrudja in particular, a territory where hydrographic network is underdeveloped, streams are ephemeral, and semi-endorheic areas are well developed. When the period of moisture deficiency lasts longer, it can bring about a significant water imbalance, which results in crop losses or restrictions in water consumption, thus leading to a number of economic problems. Under the circumstances, the risk of aridity expansion is significant, this being the reason why a better water management system in Romania is urgently needed. In the last decades, the numerous specialty studies undertaken in the area have emphasized an intensification of the process of dryness, because atmospheric and pedological droughts have become more and more serious. Romania is a member of the United Nations Convention to Combat Desertification (UNCCD and the World Meteorological Organization (WMO. It actively participates within the drought management network and the Drought Management Center for Southeastern Europe, which comprises 11 countries. The scope is to work together and exchange experience with the neighboring countries that have recorded positive results and acquired a rich experience in terms of drought management. The employment of appropriate pluvial indices in identifying the areas prone to aridity may prove to be convenient tool for finding practical solutions meant to mitigate the impact of this phenomenon on the local communities living in South Dobrudja.

  11. Southwestern desert resources

    Science.gov (United States)

    Halvorson, William L.; van Riper, Charles; Schwalbe, Cecil R.

    2010-01-01

    The southwestern deserts stretch from southeastern California to west Texas and then south to central Mexico. The landscape of this region is known as basin and range topography featuring to "sky islands" of forest rising from the desert lowlands which creates a uniquely diverse ecology. The region is further complicated by an international border, where governments have caused difficulties for many animal populations. This book puts a spotlight on individual research projects which are specific examples of work being done in the area and when they are all brought together, to shed a general light of understanding the biological and cultural resources of this vast region so that those same resources can be managed as effectively and efficiently as possible. The intent is to show that collaborative efforts among federal, state agency, university, and private sector researchers working with land managers, provides better science and better management than when scientists and land managers work independently.

  12. Native American Student Resiliency within Southwestern Tribal Colleges

    Science.gov (United States)

    Peralez, Elizabeth

    2014-01-01

    The purpose of this study was to explore the degree to which Native American culture impacts the resiliency of Native American students earning degrees at three tribal colleges in the southwestern part of the United States. This study was a qualitative case study that was based on the following research question: "How does Native American…

  13. Integrated Water Resources Planning and Management in Arid/Semi-arid Regions: Data, Modeling, and Assessment

    Science.gov (United States)

    Gupta, H.; Liu, Y.; Wagener, T.; Durcik, M.; Duffy, C.; Springer, E.

    2005-12-01

    Water resources in arid and semi-arid regions are highly sensitive to climate variability and change. As the demand for water continues to increase due to economic and population growth, planning and management of available water resources under climate uncertainties becomes increasingly critical in order to achieve basin-scale water sustainability (i.e., to ensure a long-term balance between supply and demand of water).The tremendous complexity of the interactions between the natural hydrologic system and the human environment means that modeling is the only available mechanism for properly integrating new knowledge into the decision-making process. Basin-scale integrated models have the potential to allow us to study the feedback processes between the physical and human systems (including institutional, engineering, and behavioral components); and an integrated assessment of the potential second- and higher-order effects of political and management decisions can aid in the selection of a rational water-resources policy. Data and information, especially hydrological and water-use data, are critical to the integrated modeling and assessment for water resources management of any region. To this end we are in the process of developing a multi-resolution integrated modeling and assessment framework for the south-western USA, which can be used to generate simulations of the probable effects of human actions while taking into account the uncertainties brought about by future climatic variability and change. Data are being collected (including the development of a hydro-geospatial database) and used in support of the modeling and assessment activities. This paper will present a blueprint of the modeling framework, describe achievements so far and discuss the science questions which still require answers with a particular emphasis on issues related to dry regions.

  14. The role of climate change in the widespread mortality of Holm oak in open woodlands of Southwestern Spain

    OpenAIRE

    Natalini, Fabio; Alejano Monge, Reyes; Vázquez Piqué, Javier; Cañellas, Isabel; Gea Izquierdo, Guillermo

    2016-01-01

    Forest decline and increasing tree mortality are of global concern and the identification of the causes is necessary to develop preventive measures. Global warming is an emerging factor responsible for the increasing tree mortality in drought-prone ecosystems. In the southwestern Iberian Peninsula, Mediterranean holm oak open woodlands currently undergo large-scale population-level tree die-off. In this region, temperature and aridity have increased during recent decades, but the ...

  15. Dust aerosol effect on semi-arid climate over Northwest China detected from A-Train satellite measurements

    OpenAIRE

    Huang, J; Minnis, P.; Yan, H; Yi, Y.; Chen, B; Zhang, L.; J. K. Ayers

    2010-01-01

    The impact of dust aerosols on the semi-arid climate of Northwest China is analyzed by comparing aerosol and cloud properties derived over the China semi-arid region (hereafter, CSR) and the United States semi-arid region (hereafter, USR) using several years of surface and A-Train satellite observations during active dust event seasons. These regions have similar climatic conditions, but aerosol concentrations are greater over the CSR. Because the CSR is close to two major dust source regions...

  16. New crops for arid lands.

    Science.gov (United States)

    Hinman, C W

    1984-09-28

    Five plants are described that could be grown commercially under arid conditions. Once the most valuable component has been obtained from each plant (rubber from guayule; seed oil from jojoba, buffalo gourd, and bladderpod; and resin from gumweed), the remaining material holds potential for useful products as well as fuel. It is difficult to realize the full potential of arid land plants, however, because of the complexities of developing the necessary agricultural and industrial infrastructure simultaneously. To do so, multicompany efforts or cooperative efforts between government and the private sector will be required.

  17. Impacts of urbanization on groundwater quality and recharge in a semi-arid alluvial basin

    Science.gov (United States)

    Carlson, Mark A.; Lohse, Kathleen A.; McIntosh, Jennifer C.; McLain, Jean E. T.

    2011-10-01

    SummaryThe management of groundwater resources is paramount in semi-arid regions experiencing urban development. In the southwestern United States, enhancing recharge of urban storm runoff has been identified as a strategy for augmenting groundwater resources. An understanding of how urbanization may impact the timing of groundwater recharge and its quality is a prerequisite for mitigating water scarcity and identifying vulnerability to contamination. We sampled groundwater wells along the Rillito Creek in southern Arizona that had been previously analyzed for tritium in the late 1980s to early 1990s and analyzed samples for tritium ( 3H) and helium-3 ( 3H/ 3He) to evaluate changes in 3H and age date groundwaters. Groundwater samples were also analyzed for chlorofluorocarbons (CFCs) and basic water quality metrics. Substantial changes in 3H values from waters sampled in the early 1990s compared to 2009 were identified after accounting for radioactive decay and indicate areas of rapid recharge. 3H- 3He groundwater ages ranged from 22 years before 2009 to modern recharge. CFC-11, -12 and -113 concentrations were anomalously high across the basin, and non-point source pollution in runoff and/or leaky infrastructure was identified as the most plausible source of this contamination. CFCs were strongly and positively correlated to nitrate ( r2 = 0.77) and a mobile trace metal, nickel ( r2 = 0.71), suggesting that solutes were derived from a similar source. Findings from this study suggest new waters from urban non-point sources are contributing to groundwater recharge and adversely affecting water quality. Reducing delivery of contaminants to areas of focused recharge will be critical to protect future groundwater resources.

  18. Stability measures in arid ecosystems

    Science.gov (United States)

    Nosshi, M. I.; Brunsell, N. A.; Koerner, S.

    2015-12-01

    Stability, the capacity of ecosystems to persist in the face of change, has proven its relevance as a fundamental component of ecological theory. Here, we would like to explore meaningful and quantifiable metrics to define stability, with a focus on highly variable arid and semi-arid savanna ecosystems. Recognizing the importance of a characteristic timescale to any definition of stability, our metrics will be focused scales from annual to multi-annual, capturing different aspects of stability. Our three measures of stability, in increasing order of temporal scale, are: (1) Ecosystem resistance, quantified as the degree to which the system maintains its mean state in response to a perturbation (drought), based on inter-annual variability in Normalized Difference Vegetation Index (NDVI). (2) An optimization approach, relevant to arid systems with pulse dynamics, that models vegetation structure and function based on a trade off between the ability to respond to resource availability and avoid stress. (3) Community resilience, measured as species turnover rate (β diversity). Understanding the nature of stability in structurally-diverse arid ecosystems, which are highly variable, yields theoretical insight which has practical implications.

  19. Southwestern Power Administration Update, October- December 2004

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-12-01

    On October 29, 2004, Southwestern and Southwest Power Pool, Inc. (SPP) reached agreement on interim arrangements to be implemented after the October 31, 2004, expiration of the membership agreement between the two parties. According to Jim McDonald, Director of Southwestern’s Division of Customer Service, the interim agreement forged between Southwestern and SPP seeks to minimize impacts to SPP as well as to Southwestern and its customers while Southwestern and SPP work on a seams/coordination agreement to succeed the expired membership agreement.

  20. Annual plants in arid and semi-arid desert regions

    Institute of Scientific and Technical Information of China (English)

    Xuehua LI; Xiaolan LI; Deming JIANG; Zhimin LIU; Qinghe YU

    2008-01-01

    Annual plants are the main vegetation in arid and semi-arid desert regions.Because of their unique traits,they are the optimal experimental subjects for eco-logical studies.In this article,we summarize annual plants' seed germination strategies,seedling adaptability mechanism to environments,seed dispersal,and soil seed banks.We also discuss the biotic and abiotic factors affecting the composition and dynamics of annual plant populations and communities.Because annual plants have important ecological functions in desert vegetation systems,this study on annual plants will be of great bene-fit to the conservation and restoration of desert ecosys-tems,the rational utilization of resources,and the sustainable development of desert regions.

  1. Southwestern Power Administration Combined Financial Statements, 2006-2009

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-09-01

    We have audited the accompanying combined balance sheets of the Southwestern Federal Power System (SWFPS), as of September 30, 2009, 2008, 2007, and 2006, and the related combined statements of revenues and expenses, changes in capitalization, and cash flows for the years then ended. As described in note 1(a), the combined financial statement presentation includes the hydroelectric generation functions of another Federal agency (hereinafter referred to as the generating agency), for which Southwestern Power Administration (Southwestern) markets and transmits power. These combined financial statements are the responsibility of the management of Southwestern and the generating agency. Our responsibility is to express an opinion on these combined financial statements based on our audits. We conducted our audits in accordance with auditing standards generally accepted in the United States of America. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the combined financial statements are free of material misstatement. An audit includes consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of Southwestern and the generating agency’s internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the combined financial statements, assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall combined financial statement presentation. We believe that our audits provide a reasonable basis for our opinion. In our opinion, the combined financial statements referred to above present fairly, in all material respects, the respective financial position of the Southwestern Federal Power

  2. Arid Lands Biofuel

    Science.gov (United States)

    Neupane, B. P.

    2013-05-01

    Dependence on imported petroleum, as well as consequences from burning fossil fuels, has increased the demand for biofuel sources in the United States. Competition between food crops and biofuel crops has been an increasing concern, however, since it has the potential to raise prices for US beef and grain products due to land and resource competition. Biofuel crops that can be grown on land not suitable for food crops are thus attractive, but also need to produce biofuels in a financially sustainable manner. In the intermountain west of Nevada, biofuel crops need to survive on low-organic soils with limited precipitation when grown in areas that are not competing with food and feed. The plants must also yield an oil content sufficiently high to allow economically viable fuel production, including growing and harvesting the crop as well as converting the hydrocarbons into a liquid fuel. Gumweed (Grindelia squarrosa) currently appears to satisfy all of these requirements and is commonly observed throughout the west. The plant favors dry, sandy soils and is most commonly found on roadsides and other freshly disturbed land. A warm season biennial, the gumweed plant is part of the sunflower family and normally grows 2-4 feet high with numerous yellow flowers and curly leaves. The gumweed plant contains a large store of diterpene resins—most abundantly grindelic acid— similar to the saps found on pine trees that are used to make inks and adhesives. The dry weight harvest on the experimental field is 5130 lbs/acre. Whole plant biomass yields between 11-15% (average 13%) biocrude when subjected to acetone extraction whereas the buds alone contains up to a maximum of 35% biocrude when harvested in 'white milky' stage. The extract is then converted to basic form (sodium grindelate) followed by extraction of nonpolar constituents (mostly terpenes) with hexane and extracted back to ethyl acetate in acidified condition. Ethyl acetate is removed under vacuum to leave a dark

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of residuum in southwestern Georgia and southeastern Alabama

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. CHARACTERISTICS OF ARIDITY CONDITIONS IN SOUTH DOBRUDJA

    OpenAIRE

    A. TISCOVSCHI; GABRIELA MANEA; O. COCOS; IULIANA VIJULIE; ROXANA CUCULICI

    2013-01-01

    Characteristics of Aridity Conditions in South Dobrudja. For most people, the arid and semi-arid lands are those where precipitation is low (less than 200 mm per year), and yet enough for supplying streams capable of temporarily carrying the debris resulted from weathering, but insufficient for encouraging the development of a vegetal cover meant to protect the soil blanket against eroding agents. The drought is a major and permanent climatic risk for the Dobrudja territory as a whole and for...

  5. Southwestern Power Administration annual site environmental report CY 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    This report provides a synopsis of Southwestern Power Administration`s (Southwestern`s) effectiveness in managing its operations in an environmentally responsible manner. In CY 1997, the Office of Environmental, Safety, and Health was reorganized and incorporated into the Division of Acquisition and Property. The Division of Acquisition, Property, and Environmental Management maintains responsibility for development, oversight, and implementation of environmental programs. Senior Management at Southwestern has taken actions to increase environmental awareness throughout the organization. During CY 1997, (Southwestern) was not involved in any known programs or activities that had adverse impacts on the environment. The 1997 Environmental Appraisal, a portion of Southwestern`s Self-Assessment and Appraisal Program, indicated approximately 90% compliance with Southwestern`s written environmental programs. Southwestern continued to function throughout CY 1997 in an operations and maintenance posture with minor substation projects.

  6. Development of a regression model to predict copper toxicity to Daphnia magna and site-specific copper criteria across multiple surface-water drainages in an arid landscape.

    Science.gov (United States)

    Fulton, Barry A; Meyer, Joseph S

    2014-08-01

    The water effect ratio (WER) procedure developed by the US Environmental Protection Agency is commonly used to derive site-specific criteria for point-source metal discharges into perennial waters. However, experience is limited with this method in the ephemeral and intermittent systems typical of arid climates. The present study presents a regression model to develop WER-based site-specific criteria for a network of ephemeral and intermittent streams influenced by nonpoint sources of Cu in the southwestern United States. Acute (48-h) Cu toxicity tests were performed concurrently with Daphnia magna in site water samples and hardness-matched laboratory waters. Median effect concentrations (EC50s) for Cu in site water samples (n=17) varied by more than 12-fold, and the range of calculated WER values was similar. Statistically significant (α=0.05) univariate predictors of site-specific Cu toxicity included (in sequence of decreasing significance) dissolved organic carbon (DOC), hardness/alkalinity ratio, alkalinity, K, and total dissolved solids. A multiple-regression model developed from a combination of DOC and alkalinity explained 85% of the toxicity variability in site water samples, providing a strong predictive tool that can be used in the WER framework when site-specific criteria values are derived. The biotic ligand model (BLM) underpredicted toxicity in site waters by more than 2-fold. Adjustments to the default BLM parameters improved the model's performance but did not provide a better predictive tool compared with the regression model developed from DOC and alkalinity.

  7. Uranium isotopes in carbonate aquifers of arid region setting

    DEFF Research Database (Denmark)

    Alshamsi, Dalal M.; Murad, Ahmed A.; Aldahan, Ala;

    2013-01-01

    Groundwater in arid and semiarid regions is vital resource for many uses and therefore information about concentrations of uranium isotopes among other chemical parameters are necessary. In the study presented here, distribution of 238U and 235U in groundwater of four selected locations in the so......Groundwater in arid and semiarid regions is vital resource for many uses and therefore information about concentrations of uranium isotopes among other chemical parameters are necessary. In the study presented here, distribution of 238U and 235U in groundwater of four selected locations...... in the southern Arabian peninsula, namely at two locations within the United Arab Emirates (UAE) and two locations in Oman are discussed. The analyses of the uranium isotopes were performed using ICP-MS and the results indicated a range of concentrations for 235U and 238 U at 3–39 ng L-1 (average: 18 ng L-1...

  8. Diallel Analysis of Southwestern Corn Borer Leaf Feeding Damage in Maize

    Science.gov (United States)

    Southwestern corn borer [Diatraea grandiosella (Dyar)] is an important pest of maize in the southern United States. It feeds extensively within the leaf whorls of plants in the vegetative stages of growth. This reduces both the quantity and quality of harvestable grain. Germplasm lines with resistan...

  9. SIZE AND COMPOSITION OF VISIBILITY-REDUCING AEROSOLS IN SOUTHWESTERN PLUMES

    Science.gov (United States)

    The southwestern United States desert and mountain areas are generally characterized by very good visibility. Until recent years, scenic vistas of natural landmarks and mountains with a visual range of over 100 miles were common. These vistas have been considered a major resource...

  10. On plate tectonics and the geologic evolution of southwestern North America

    Science.gov (United States)

    Ward, P.L.

    1991-01-01

    Very rapid subduction of the Farallon plate under southwestern North America between 60 and 40 Ma was accompanied by a relatively low volume of magmatism throughout the southwestern United States and northern Mexico. Between 40 and 20 Ma, when subduction slowed significantly and in one area may have even stopped, magmatism became widespread and voluminous from Nevada and Utah to central Mexico. This correlation of rapid subduction with a relatively low volume of magmatism can be explained by the observation that subduction-related andesitic arc volcanism, often formed in a Laramide-style compressional regime, is relatively low volume compared to continental volcanism. -from Author

  11. Southwestern Power Administration Annual Report 2012

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-09-01

    Dear Secretary Moniz: I am pleased to present the financial statements and operating data for Southwestern Power Administration (Southwestern) for Fiscal Year (FY) 2012. In FY 2012, Southwestern delivered over 4.1 billion kilowatt-hours of energy to its wholesale customers in Arkansas, Kansas, Louisiana, Missouri, Oklahoma, and Texas, generating $195 million in revenue. In fulfilling its mission to market and reliably deliver renewable Federal hydroelectric power, Southwestern maintains 1,380 miles of high-voltage transmission lines, substations, and communications sites, contributing to the reliability of the regional and National electric grid. Southwestern also actively partners with the Department of Energy, the U.S. Army Corps of Engineers, Southwestern’s customers, and other Federal power stakeholders to most effectively balance their diverse interests with Southwestern’s mission while continuing to maximize Federal assets to repay the Federal investment in the 24 hydropower facilities within Southwestern’s marketing region. Southwestern is proud of its past successes, and we look forward to continuing to serve the Nation’s energy needs in the future. Sincerely, Christopher M. Turner Administrator

  12. Southwestern Power Administration Annual Report 2011

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-04-01

    Dear Secretary Chu: I am pleased to present the financial statements and operating data for Southwestern Power Administration (Southwestern) for Fiscal Year (FY) 2011. In FY 2011, Southwestern delivered over 4.1 billion kilowatt-hours of energy to its wholesale customers in Arkansas, Kansas, Louisiana, Missouri, Oklahoma, and Texas, generating $167 million in revenue. In fulfilling its mission to market and reliably deliver renewable Federal hydroelectric power, Southwestern maintains 1,380 miles of high-voltage transmission lines, substations, and communications sites, contributing to the reliability of the regional and National electric grid. Southwestern also actively partners with the Department of Energy, the U.S. Army Corps of Engineers, Southwestern’s customers, and other Federal power stakeholders to most effectively balance their diverse interests with Southwestern’s mission while continuing to maximize Federal assets to repay the Federal investment in the 24 hydropower facilities within Southwestern’s marketing region. Southwestern is proud of its past successes, and we look forward to continuing to serve the Nation’s energy needs in the future. Sincerely, Christopher M. Turner Administrator

  13. Southwestern Power Administration Annual Report 2010

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-09-01

    Dear Secretary Chu: I am pleased to present the financial statements and operating data for Southwestern Power Administration (Southwestern) for Fiscal Year (FY) 2010. In FY 2010, Southwestern delivered nearly 7.6 billion kilowatt-hours of energy to its wholesale customers in Arkansas, Kansas, Louisiana, Missouri, Texas, and Oklahoma, generating $189 million in revenue. In fulfilling its mission to market and reliably deliver renewable Federal hydroelectric power, Southwestern maintains 1,380 miles of high-voltage transmission lines, substations, and communications sites, contributing to the reliability of the regional and National electric grid. Southwestern also actively partners with the Department of Energy, the U.S. Army Corps of Engineers, Southwestern’s customers, and other Federal power stakeholders to most effectively balance their diverse interests with Southwestern’s mission while continuing to maximize Federal assets to repay the Federal investment in the 24 hydropower facilities within Southwestern’s marketing region. Southwestern is proud of its past successes, and we look forward to continuing to serve the Nation’s energy needs in the future. Sincerely, Christopher M. Turner Administrator

  14. Screening Prosopis (mesquite) species for biofuel production on semi-arid lands. Final report, April 1, 1978-March 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P; Cannell, G H; Clark, P R; Osborn, J F; Nash, P

    1985-01-01

    Arid adapted nitrogen fixing trees and shrubs of the genus Prosopis (mesquite) have been examined for woody biomass production on semi-arid lands of southwestern United States. A germ-plasm collection of 900 accessions from North and South America and Africa was assembled. Field studies screening for biomass production, frost tolerance, response to irrigation, pod production and heat/drought tolerance involved a total of 80 accessions. Selections made from survivors of coal/frost screening trial had more frost tolerance and biomass productivity than prostrate selections from the ranges of Arizona, New Mexico and west Texas. Thirteen Prosopis species were found to nodulate, reduce acetylene to ethylene, and grow on a nitrogen free media in greenhouse experiments. The salinity tolerance of six Prosopis species was examined on a nitrogen free media in greenhouse experiments. No reduction in growth occurred for any species tested at a salinity of 6000 mg NaC1/L which is considered too saline for normal agricultural crops. Individual trees have grown 5 to 7 cm in basal diameter, and 2.0 to 3.7 meters in height per year and have achieved 50 kg oven dry weight per tree in 2 years with 600 mm water application per year. Vegetative propagation techniques have been developed and clones of these highly productive trees have been made. Small pilots on 1.5 x 1.5 m spacing in the California Imperial Valley had a first and second season dry matter production of 11.7 and 16.9 T/ha for P. chilensis (0009), 7.1 and 6.9 T/ha for P. glandulosa var. torreyana (0001), 9.8 and 19.2 T/ha for P. alba (0039) and 7.9 and 14.5 T/ha for progency of a California ornamental (0163). The projected harvested costs of $25.00 per oven dry ton or $1.50 per million Btu's compare favorable with coal and other alternative fuel sources in South Texas.

  15. Physiological stress in koala populations near the arid edge of their distribution.

    Directory of Open Access Journals (Sweden)

    Nicole Ashley Davies

    Full Text Available Recent research has shown that the ecology of stress has hitherto been neglected, but it is in fact an important influence on the distribution and numbers of wild vertebrates. Environmental changes have the potential to cause physiological stress that can affect population dynamics. Detailed information on the influence of environmental variables on glucocorticoid levels (a measure of stress at the trailing edge of a species' distribution can highlight stressors that potentially threaten species and thereby help explain how environmental challenges, such as climate change, will affect the survival of these populations. Rainfall determines leaf moisture and/or nutritional content, which in turn impacts on cortisol concentrations. We show that higher faecal cortisol metabolite (FCM levels in koala populations at the trailing arid edge of their range in southwestern Queensland are associated with lower rainfall levels (especially rainfall from the previous two months, indicating an increase in physiological stress when moisture levels are low. These results show that koalas at the semi-arid, inland edge of their geographic range, will fail to cope with increasing aridity from climate change. The results demonstrate the importance of integrating physiological assessments into ecological studies to identify stressors that have the potential to compromise the long-term survival of threatened species. This finding points to the need for research to link these stressors to demographic decline to ensure a more comprehensive understanding of species' responses to climate change.

  16. Physiological stress in koala populations near the arid edge of their distribution.

    Science.gov (United States)

    Davies, Nicole Ashley; Gramotnev, Galina; McAlpine, Clive; Seabrook, Leonie; Baxter, Greg; Lunney, Daniel; Rhodes, Jonathan R; Bradley, Adrian

    2013-01-01

    Recent research has shown that the ecology of stress has hitherto been neglected, but it is in fact an important influence on the distribution and numbers of wild vertebrates. Environmental changes have the potential to cause physiological stress that can affect population dynamics. Detailed information on the influence of environmental variables on glucocorticoid levels (a measure of stress) at the trailing edge of a species' distribution can highlight stressors that potentially threaten species and thereby help explain how environmental challenges, such as climate change, will affect the survival of these populations. Rainfall determines leaf moisture and/or nutritional content, which in turn impacts on cortisol concentrations. We show that higher faecal cortisol metabolite (FCM) levels in koala populations at the trailing arid edge of their range in southwestern Queensland are associated with lower rainfall levels (especially rainfall from the previous two months), indicating an increase in physiological stress when moisture levels are low. These results show that koalas at the semi-arid, inland edge of their geographic range, will fail to cope with increasing aridity from climate change. The results demonstrate the importance of integrating physiological assessments into ecological studies to identify stressors that have the potential to compromise the long-term survival of threatened species. This finding points to the need for research to link these stressors to demographic decline to ensure a more comprehensive understanding of species' responses to climate change.

  17. Using NDVI to measure precipitation in semi-arid landscapes

    Science.gov (United States)

    Birtwhistle, Amy N.; Laituri, Melinda; Bledsoe, Brian; Friedman, Jonathan M.

    2016-01-01

    Measuring precipitation in semi-arid landscapes is important for understanding the processes related to rainfall and run-off; however, measuring precipitation accurately can often be challenging especially within remote regions where precipitation instruments are scarce. Typically, rain-gauges are sparsely distributed and research comparing rain-gauge and RADAR precipitation estimates reveal that RADAR data are often misleading, especially for monsoon season convective storms. This study investigates an alternative way to map the spatial and temporal variation of precipitation inputs along ephemeral stream channels using Normalized Difference Vegetation Index (NDVI) derived from Landsat Thematic Mapper imagery. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG), a region covering 3,367 km2 of semiarid landscapes in southwestern Arizona, USA. The change in NDVI from a pre-to post-monsoon season image along ephemeral stream channels explained 73% of the variance in annual monsoonal precipitation totals from a nearby rain-gauge. In addition, large seasonal changes in NDVI along channels were useful in determining when and where flow events have occurred.

  18. Enrollment Management in Academic Units

    Science.gov (United States)

    DeBiaso, Nick

    2012-01-01

    This study provides an understanding of how administrative leaders make decisions regarding enrollment management within academic units at a major research university in the southwestern United States. Key enrollment management functions of recruiting, admissions, marketing, orientation, financial aid/scholarships, academic advising, student…

  19. SCIENCES IN COLD AND ARID REGIONS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Aims and Scope Sciences in Cold and Arid Regions, an international Engiish-language journal, is devoted to publishing the latest research achievements on the process and the pattern of Earth surface system in cold and arid regions. Researches in cold regions 1) emphasize particularly on the cold-region-characterized physical, chemical and biological processes and their interactions, and on the response of Cryosphere to Global change and Human activities as well as its effect to environment and the acclimatizable

  20. Energy Requirements by the Water Sector in the Southwestern US: Past, Present, and Future

    Science.gov (United States)

    Averyt, K.; Yates, D. N.; Meldrum, J.

    2014-12-01

    Climate, energy, and water are fundamentally linked such that shifts in one sector have cascading impacts on the others. Consideration of the integrated system is necessary to fully understand the individual risk profile of each sector. In defining vulnerabilities and potential adaptations, the policy and regulatory environment must be considered alongside the biological and physical systems. Take, for example, the Southwestern U.S., a naturally arid system, where water availability is declining as a consequence of climate change and population growth. Adaptations by the water sector to convey, store, and develop new water sources (e.g. desalination, groundwater pumping, water-reuse) are strategies designed to enhance sustainability of the sector. But, the energy requirements embedded in these management techniques pose challenges to electric utilities. West wide, approximately 20% of total electricity generation goes toward supplying and heating water. If future investments made by the water sector to deal with changing supply and demand regimes continue to follow current trends, the dependence of water on energy availability will grow, meaning that the water supply will be increasingly reliant on the electricity system. Here, we use the example of long-term aridity and the recent drought in the Western US to illustrate the tradeoffs and challenges inherent at the nexus between energy and water. We present long-term trends in the energy intensity of water supplies in the Southwestern US, with a specific focus on groundwater systems. Projected energy requirements for proposed and future conveyance systems are discussed. The potential impacts of reduced flows on the Colorado River on the energy demands for groundwater pumping in the Lower Colorado River Basin are highlighted.

  1. Rainwater harvesting in arid and semi-arid zones (repr. 1997)

    NARCIS (Netherlands)

    Boers, Th.M.

    1994-01-01

    In arid and semi-arid regions, the scarcity of water can be alleviated by rainwater harvesting, which is defined as a method of inducing, collecting, storing, and conserving local surface runoff for agriculture. Rainwater harvesting can be applied with different systems, and this dissertation deals

  2. Southwestern Institute of Physics annual report (2000)

    International Nuclear Information System (INIS)

    The research results and engineering progress of SWIP (Southwestern Institute of Physics) during the year of 2000 was summarized in this annual report. The contents divided into five parts: 1. tokamak experimental diagnoses and tokamak engineering; 2. fusion reactor and fusion reactor materials; 3. plasma theory and calculation; 4. technique development and application; 5. appendix 31 theses and presented in this report

  3. Casuses of deforestation in southwestern Madagascar

    DEFF Research Database (Denmark)

    Casse, Thorkil; Milhøj, Anders; Ranaivoson, Socrate;

    2004-01-01

    Causes of deforestation are discussed in the case of southwestern Madagascar. Distinction is made between direct and indirect causes. The article ends up with an estimation of the value of agricultural land vs. an estimation of benefits from utilisation of non-timber forest products...

  4. Southwestern Power Administration site environmental report for calendar year 1993

    International Nuclear Information System (INIS)

    During CY 93, Southwestern was not involved in any programs that had a direct effect on the environment, involving endangered species, protection of wetlands, or increased electromagnetic radiation. Southwestern continued to function throughout the year in an operations and maintenance posture with minor substation projects. Southwestern received an environmental management audit by the Department of Energy's Office of Environmental Audit (EH-24), during CY 1992. The purpose of the audit was to give Southwestern, DOE headquarters, and the Secretary an indication of the status of Southwestern management's effectiveness in discharging its duties in an environmentally responsible manner. The audit identified 17 findings. An action plan was developed and remediation of the findings has been accomplished. Several strengths were identified during the audit with regard to the environmental programs at Southwestern. Most importantly, senior management at Southwestern has taken actions to increase environmental awareness throughout the organization which is evidenced by the creation of the Environmental, Safety, Health, and Security Office

  5. Occurrence and treatment of arsenic in groundwater and soil in northern Mexico and southwestern USA.

    Science.gov (United States)

    Camacho, Lucy Mar; Gutiérrez, Mélida; Alarcón-Herrera, Maria Teresa; Villalba, Maria de Lourdes; Deng, Shuguang

    2011-04-01

    This review focuses on the occurrence and treatment of arsenic (As) in the arid region of northern Mexico (states of Chihuahua and Coahuila) and bordering states of the southwestern US (New Mexico, Arizona, and Texas), an area known for having high As concentrations. Information assembled and assessed includes the content and probable source of As in water, soil, and sediments and treatment methods that have been applied in the area. High As concentrations were found mainly in groundwater, their source being mostly from natural origin related to volcanic processes with significant anthropogenic contributions near mining and smelting of ores containing arsenic. The affinity of As for solid phases in alkaline conditions common to arid areas precludes it from being present in surface waters, accumulating instead in sediments and shifting its threat to its potential remobilization in reservoir sediments and irrigation waterways. Factors such as oxidation and pH that affect the mobility of As in the subsurface environment are mentioned. Independent of socio-demographic variables, nutritional status, and levels of blood lead, cognitive development in children is being affected when exposed to As. Treatments known to effectively reduce As content to safe drinking water levels as well as those that are capable of reducing As content in soils are discussed. Besides conventional methods, emergent technologies, such as phytoremediation, offer a viable solution to As contamination in drinking water.

  6. Engaging Southwestern Tribes in Sustainable Water Resources Topics and Management

    Directory of Open Access Journals (Sweden)

    Karletta Chief

    2016-08-01

    Full Text Available Indigenous peoples in North America have a long history of understanding their societies as having an intimate relationship with their physical environments. Their cultures, traditions, and identities are based on the ecosystems and sacred places that shape their world. Their respect for their ancestors and ‘Mother Earth’ speaks of unique value and knowledge systems different than the value and knowledge systems of the dominant United States settler society. The value and knowledge systems of each indigenous and non-indigenous community are different but collide when water resources are endangered. One of the challenges that face indigenous people regarding the management of water relates to their opposition to the commodification of water for availability to select individuals. External researchers seeking to work with indigenous peoples on water research or management must learn how to design research or water management projects that respect indigenous cultural contexts, histories of interactions with settler governments and researchers, and the current socio-economic and political situations in which indigenous peoples are embedded. They should pay particular attention to the process of collaborating on water resource topics and management with and among indigenous communities while integrating Western and indigenous sciences in ways that are beneficial to both knowledge systems. The objectives of this paper are to (1 to provide an overview of the context of current indigenous water management issues, especially for the U.S. federally recognized tribes in the Southwestern United States; (2 to synthesize approaches to engage indigenous persons, communities, and governments on water resources topics and management; and (3 to compare the successes of engaging Southwestern tribes in five examples to highlight some significant activities for collaborating with tribes on water resources research and management. In discussing the engagement

  7. Southwestern Power Administration Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-12-01

    Dear Secretary Chu, I am pleased to present the financial statements and operating data for Southwestern Power Administration (Southwestern) for Fiscal Year (FY) 2008. In FY 2008, Southwestern delivered over 7.3 billion kilowatt-hours of energy to its wholesale customers – nearly 31% more than average due to numerous record rainfall amounts in the southwest region. These record amounts produced revenues which exceeded the average annual revenue requirement by nearly $20 million and resulted in over $200 million in economic benefits to the region. Yet even as Southwestern exceeded its goals of marketing and delivering Federal hydroelectric power to our customers, we stayed focused on safety, security, and reliability. For example, we maintained our nearly 1,400 miles of high-voltage transmission lines, substations, and communications sites while achieving a Recordable Accident Frequency Rate of 0.0, a record that reflects Southwestern’s safety achievement of no recordable injuries for every 200,000 hours worked. We kept our rights-of-way secure from vegetation and other obstacles, work that not only supports our mission but also promotes reliability of the regional and National grid. We exceeded all North American Electric Reliability Corporation (NERC) Control Performance Standards (CPS- 1 and CPS-2), and maintained regulation and reserve obligations and reactive reserve margins to ensure the reliability of the bulk electric system, even during extended periods of restricted hydro operations due to unusually high project inflows. Finally, we continued our partnerships with the Department of Energy, the U.S. Army Corps of Engineers, our customers, and other Federal power stakeholders, partnerships that are vital to our continued success in marketing and delivering carbon-free, renewable, and domestically produced energy to our customers and to the Nation. Sincerely, Jon Worthington Administrator

  8. Study on RS- and GIS-based ecological capital assessment in arid areas

    Institute of Scientific and Technical Information of China (English)

    ZHOU Kefa; CHEN Xi; ZHOU Huarong; ZHANG Qing; ZUO Qiting; ZHANG Haibo; YAN Jinfeng; CHEN Chuan

    2006-01-01

    Ecological capital assessment is currently one of the important research contents in the interdisciplinary field of ecology, resources economics, environmental economics and ecological economics. To scientifically assess ecological capital redounds to decision-makers to consider the ecological cost in economic development, and is also necessary for sustainable economic development in arid areas. Based on the theory of landscape ecology,in this paper the per unit area ecological capital values in arid areas are researched by using the Landsat TM data, CBERS satellite data, meteorological data, MODIS satellite data and other ecological data,and the RS- and GIS-based models of assessing ecological capital values in arid areas are developed.Moreover, based on the field-measured data, a case study on ecological capital assessment in the Manas River basin, Xinjiang in 2003 is carried out. The basin is divided into 4 ecological capital areas so as to quantitatively calculate the ecological capital values of the ecosystems, analyze the spatial distribution of ecological capital, and chart the maps of spatial distribution of ecological capital. The results show that the total ecological capital value of the ecosystems in the Manas River basin in 2003 was 1.49454×1011yuan RMB. In spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the distribution of vegetation zonality in this arid area.The assessed results can objectively reflect the ecological capital and its spatial distribution in the arid basin, and can also provide reference for roundly carrying out the assessment of ecological capital in arid areas.

  9. Conservation and restoration of degraded ecosystems in arid and semi-arid areas of northwest China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In "West Development" of China, one of the most important activities is the Natural Forest Protection Program, designed to swiftly convert the focus of management and utilization of the natural forests from a timber orientation towards forest conservation, sustainable management and environmental protection. The project covered almost all the arid and semi-arid regions in Northwest region. Accompanying this great campaign this paper studied the conservation and restoration model of degraded ecosystems in arid and semi-arid lands in Northwest China. The past practices have resulted in considerably natural forest degradation and loss through land conversion (primarily for agriculture), over-harvesting, inadequate reforestation and lack of protection. The consequences have been the loss of soil and water resources, diminished timber production capacity on a sustainable basis, and environmental losses. This paper applied Aronson's restoration model and proposed the conservation, restoration, re-allocation and preservation program for the implementation of environmental improvement and natural forest conservation.

  10. Isotope techniques in water resource investigations in arid and semi-arid regions

    International Nuclear Information System (INIS)

    The Co-ordinated Research Project (CRP) on the Use of Isotope Techniques in Water Resources Investigations in Arid and Semi-arid Regions was initiated with the aim od contributing to the assessment of groundwater resources in arid areas through the use of environmental isotope techniques, and thereby to help in better management of these valuable fresh groundwater resources. The main emphases identified were in three key areas: (i) the evaluation of water balance components such as recharge rate estimation and recharge and discharge cycles at different spatial scales, (ii) paleohydrology and hydroclimatic change and, (iii) anthropogenic impacts and the assessment of the vulnerability of arid zone ground waters to salinisation and pollution impacts. This publication presents individual projects carried out within the frameworks of the CRP. Each paper has been indexed separately

  11. Applying animal behavior to arid rangeland mangement

    Science.gov (United States)

    Livestock production is one of many demands placed on today’s arid rangelands. Therefore, understanding plant and animal biology and their effects on biotic and abiotic landscape components is fundamental if rangelands are to remain ecologically sustainable. One limiting factor to accomplishing posi...

  12. Spatial interactions and resilience in arid ecosystems

    NARCIS (Netherlands)

    Koppel, van de J.; Rietkerk, M.

    2004-01-01

    We present a mathematical analysis of the consequences of spatial interactions between vegetation patches by means of water flow for the functioning of arid systems. Our model results suggest that spatial exchange of water improved the resilience to disturbances and increased the resistance to human

  13. The International Workshop on Environmental Changes and Sustainable Development in Arid and Semi-arid Regions

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Yang; Arthur Conacher

    2007-01-01

    @@ Arid regions,dominated by deserts,are characterized by a severe shortage of moisture,and a lack of perennial and integrated systems of drainage.Distributed over a very large range of temperatures,from the very hot to the very cold zones,arid regions cover about one third of the world's land surface and occur in every continent,including Antarctica.

  14. Atmospheric Impacts of Marcellus Shale Gas Activities in Southwestern Pennsylvania

    Science.gov (United States)

    Presto, A. A.; Lipsky, E. M.; Saleh, R.; Donahue, N. M.; Robinson, A. L.

    2012-12-01

    Pittsburgh and the surrounding regions of southwestern Pennsylvania are subject to intensive natural gas exploration, drilling, and extraction associated with the Marcellus Shale formation. Gas extraction from the shale formation uses techniques of horizontal drilling followed by hydraulic fracturing. There are significant concerns about air pollutant emissions from the development and production of shale gas, especially methane emissions. We have deployed a mobile monitoring unit to investigate the atmospheric impacts of Marcellus Shale gas activities. The mobile sampling platform is a van with an on-board generator, a high-resolution GPS unit, cameras, and instrumentation for measuring methane, criteria gases (SO2, NOx, CO, O3), PM size distributions (scanning mobility particle sizer), black carbon mass (multi-angle absorption photometer), particle-bound polycyclic aromatic hydrocarbons, volatile organic compounds (gas chromatograph with flame ionization detection), and meteorological data. A major advantage of the mobile sampling unit over traditional, stationary monitors is that it allows us to rapidly visit a variety of sites. Sampling at multiple sites allows us to characterize the spatial variability of pollutant concentrations related to Marcellus activity, particularly methane. Data collected from the mobile sampling unit are combined with GIS techniques and dispersion models to map pollutants related to Marcellus Shale operations. The Marcellus Shale gas activities are a major and variable source of methane. The background methane concentration in Pittsburgh is 2.1 +/- 0.2 ppm. However, two southwestern Pennsylvania counties with the highest density of Marcellus Shale wells, Washington and Greene Counties, have many areas of elevated methane concentration. Approximately 11% of the sampled sites in Washington County and nearly 50% of the sampled sites in Greene County have elevated (>2.3 ppm) methane concentrations, compared to 1.5% of sites with elevated

  15. Aridity and decomposition processes in complex landscapes

    Science.gov (United States)

    Ossola, Alessandro; Nyman, Petter

    2015-04-01

    Decomposition of organic matter is a key biogeochemical process contributing to nutrient cycles, carbon fluxes and soil development. The activity of decomposers depends on microclimate, with temperature and rainfall being major drivers. In complex terrain the fine-scale variation in microclimate (and hence water availability) as a result of slope orientation is caused by differences in incoming radiation and surface temperature. Aridity, measured as the long-term balance between net radiation and rainfall, is a metric that can be used to represent variations in water availability within the landscape. Since aridity metrics can be obtained at fine spatial scales, they could theoretically be used to investigate how decomposition processes vary across complex landscapes. In this study, four research sites were selected in tall open sclerophyll forest along a aridity gradient (Budyko dryness index ranging from 1.56 -2.22) where microclimate, litter moisture and soil moisture were monitored continuously for one year. Litter bags were packed to estimate decomposition rates (k) using leaves of a tree species not present in the study area (Eucalyptus globulus) in order to avoid home-field advantage effects. Litter mass loss was measured to assess the activity of macro-decomposers (6mm litter bag mesh size), meso-decomposers (1 mm mesh), microbes above-ground (0.2 mm mesh) and microbes below-ground (2 cm depth, 0.2 mm mesh). Four replicates for each set of bags were installed at each site and bags were collected at 1, 2, 4, 7 and 12 months since installation. We first tested whether differences in microclimate due to slope orientation have significant effects on decomposition processes. Then the dryness index was related to decomposition rates to evaluate if small-scale variation in decomposition can be predicted using readily available information on rainfall and radiation. Decomposition rates (k), calculated fitting single pool negative exponential models, generally

  16. Southwestern Power Administration Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-01-01

    “Renewable energy” isn’t just a catchphrase at Southwestern Power Administration (Southwestern). It describes the hydroelectric energy we market, and the energy that Southwestern’s employees bring to work every day, constantly challenging themselves to become more eff ective and effi cient in providing aff ordable, environmentally clean power to the American people. As Southwestern’s new Administrator, I have had the opportunity to view our operations from a fresh perspective, and I’m proud to share with you how a focus on continual improvement has been evident in accomplishments throughout the agency during fi scal year (FY) 2007. When the North American Electric Reliability Corporation (NERC) implemented new reliability standards, we met applicable implementation dates and exceeded NERC’s control performance standards throughout the year. When tasked with reducing the agency’s carbon footprint, we found ways to achieve an 8.7% reduction in energy intensity from last year without impacting our operational capabilities. And when faced with record-breaking infl ows into the reservoir projects from which we market power, we capitalized on the opportunity to provide customers with signifi cant quantities of supplemental energy. Our supplemental sales this year not only saved customers over $122 million, but increased Southwestern’s revenues -- a huge win-win for Southwestern’s ratepayers and the Nation’s taxpayers alike. Southwestern is proud of its role in protecting National and economic security by contributing to the diverse supply of domestically produced energy, operating and maintaining a safe and reliable transmission system, and ensuring good stewardship of our Nation’s water resources and environment. In FY 2007, Southwestern continued to repay all power costs to the American taxpayers by marketing and delivering approximately 5.6 billion kilowatthours of hydropower at cost-based rates to customers in our six-state region. This energy

  17. Aridity under conditions of increased CO2

    Science.gov (United States)

    Greve, Peter; Roderick, Micheal L.; Seneviratne, Sonia I.

    2016-04-01

    A string of recent of studies led to the wide-held assumption that aridity will increase under conditions of increasing atmospheric CO2 concentrations and associated global warming. Such results generally build upon analyses of changes in the 'aridity index' (the ratio of potential evaporation to precipitation) and can be described as a direct thermodynamic effect on atmospheric water demand due to increasing temperatures. However, there is widespread evidence that contradicts the 'warmer is more arid' interpretation, leading to the 'global aridity paradox' (Roderick et al. 2015, WRR). Here we provide a comprehensive assessment of modeled changes in a broad set of dryness metrics (primarily based on a range of measures of water availability) over a large range of realistic atmospheric CO2 concentrations. We use an ensemble of simulations from of state-of-the-art climate models to analyse both equilibrium climate experiments and transient historical simulations and future projections. Our results show that dryness is, under conditions of increasing atmospheric CO2 concentrations and related global warming, generally decreasing at global scales. At regional scales we do, however, identify areas that undergo changes towards drier conditions, located primarily in subtropical climate regions and the Amazon Basin. Nonetheless, the majority of regions, especially in tropical and mid- to northern high latitudes areas, display wetting conditions in a warming world. Our results contradict previous findings and highlight the need to comprehensively assess all aspects of changes in hydroclimatological conditions at the land surface. Roderick, M. L., P. Greve, and G. D. Farquhar (2015), On the assessment of aridity with changes in atmospheric CO2, Water Resour. Res., 51, 5450-5463

  18. 沉思性·议论化·隐喻化——论“西南联大诗人群”的诗语言探索与诗美追求%Meditativeness, Disputativeness and Metaphorization -- Exploration of Poetic Language and Pursuit of Poetic Aesthetics of the "Poet Group in Southwestern China United University"

    Institute of Scientific and Technical Information of China (English)

    程国君; 朱卫国

    2012-01-01

    "The Poet Group in Southwestern China United University" actively explored poetic aesthetics and practiced new poetic constructs mainly in innovation and invention of modern poetic language. First of all, They re- duced narrative and descriptive language but massively increased meditative language in poetry writing; cut down straightforward and scientific statement but added largely to rhetorical and sensitive language then, they , including paradox, metaphor, synaesthesia, irony, etc. ; finally, they deliberately invented novel expressions and strange collocations to experiment with sentence structure of modem poetry and new rules of constructing poetic lines, great- ly projecting the aesthetic effects of poetic language tension. With expressive, ironical and metaphorical language of "new experience" and symbolic "art", these poets were correcting those malpractices of new poetry in its initial days, inventing a poetic language system which was capable of expressing complex and delicate implications and ex- perience. Moreover, an obscure and "modernistic" poetic style took shape, which greatly enriched and raised the artistic quality and aesthetic taste of modern poetry.%"西南联大诗人群"的诗美探索与建构实践,主要集中在对于现代诗歌语言的革新与创造上。这种革新与实践主要体现在以下3个方面:一是诗歌中的叙述、描写性语言减少,沉思性语言大量增加;二是诗歌中的直白、科学性语言减少,矛盾修辞格、隐喻、通感、反讽等修辞性、感受性语言大量增加;三是蓄意制造文字的新奇与陌生化组合,探索现代诗句构、诗行构成的新法则,诗歌语言张力美效果凸显。当该派诗人以直观感性的、隐喻反讽的"新的感性"和象征性"艺术"语言改变着初期新诗语言直白化的弊端时,便创造了一套能够表现现代人复杂幽微意蕴与感受的诗歌语言体系。由于诗歌中象征性、隐喻性语言变

  19. INVESTIGATION OF THE GROUNDWATER SUITABILITY FOR IRRIGATION PRACTICES IN AN ARID REGION: CASE STUDY

    OpenAIRE

    Ahmed Murad

    2014-01-01

    Groundwater is an important source of acceptable water for irrigation in the arid regions and in particular in the United Arab Emirates (UAE). Demand for groundwater is increasing in the UAE due to population growth and significant economic advancement associated with political stability. As agricultural practices are the main land use in Al Hayer area, southeast UAE, majority of extracted groundwater from major aquifer is used to meet the increasing demands of irrigation. This study is aimed...

  20. New Technologies to Reclaim Arid Lands User's Manual

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler

    2002-10-01

    establishing project objectives, scheduling, budgeting, and selecting cost-effective techniques. Reclamation techniques include sections describing: (1) erosion control (physical, chemical, and biological), (2) site preparation, (3) soil amendments, (4) seeding, (5) planting, (6) grazing and weed control, (7) mulching, (8) irrigation, and (9) site protection. Each section states the objectives of the technique, the principles, an in-depth look at the techniques, and any special considerations as it relates to DoD or DOE lands. The need for monitoring and remediation is described to guide users in monitoring reclamation efforts to evaluate their cost-effectiveness. Costs are provided for the proposed techniques for the major deserts of the southwestern U.S. showing the average and range of costs. A set of decision tools are provided in the form of a flow diagram and table to guide users in selecting effective reclamation techniques to achieve mitigation objectives. Recommendations are provided to help summarize key reclamation principles and to assist users in developing a successful program that contributes to sustainable uses of DoD and DOE lands. The users manual is helpful to managers in communicating to installation management the needs and consequences of training decisions and the costs required to achieve successful levels of sustainable use. This users manual focuses on the development of new reclamation techniques that have been implemented at the National Training Center at Fort Irwin, California, and are applicable to most arid land reclamation efforts.

  1. The instrumental climate history of southwestern Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Doesken, N.J.; McKee, T.B. [Colorado State Univ., Fort Collins, CO (United States)

    1995-09-01

    Instrumental observations of the climate of southwestern Colorado date back to about 1880. Climatic conditions since the late 19th century will be described with emphasis on temperatures, temperature ranges and observed precipitation. Typical seasonal patterns of temperature and precipitation will be shown, and variations and apparent trends over time will be discussed. Drought characteristics will be described based on a standardized precipitation index developed for Colorado. Finally, brief comments on the challenge of collecting accurate and consistent long-term data will be given.

  2. The rare Chrysopidae (Neuroptera) of southwestern Europe

    Science.gov (United States)

    Canard, Michel; Letardi, Agostino; Thierry, Dominique

    2007-05-01

    Quantitative surveys of the chrysopid fauna from southwestern Europe, namely the Iberian and Italian peninsulas, France south of 46° N, and the west-Mediterranean Islands, were analysed. A total of 56 species of Chrysopidae were reported, of which three species were abundant. These, Chrysoperla carnea (Stephens, 1836) sensu lato, Dichochrysa prasina (Burmeister, 1839) and D. flavifrons (Brauer, 1850), comprised a large percentage of the specimens. For the rarer species, comments are made on their distributions, the enhanced geographic range of exotic ones, and on levels of endemism and stenotopy.

  3. Transformational Leadership and Teacher Motivation in Southwestern Arizona High Schools

    Science.gov (United States)

    Reynolds, Catherine L.

    2009-01-01

    The purpose of this study was to explore the relationship between transformational leadership and teacher motivation in Southwestern Arizona high schools. Teachers in a school district in Southwestern Arizona comprised of high schools were surveyed using two instruments, Leithwood and Jantzi's (1998) The Leadership and Management of Schools in…

  4. VOCs in Arid soils: Technology summary

    International Nuclear Information System (INIS)

    The Volatile Organic Compounds In Arid Soils Integrated Demonstration (VOC-Arid ID) focuses on technologies to clean up volatile organic compounds and associated contaminants in soil and groundwater at arid sites. The initial host site is the 200 West Area at DOE's Hanford site in southeastern Washington state. The primary VOC contaminant is carbon tetrachloride, in association with heavy metals and radionuclides. An estimated 580--920 metric tons of carbon tetrachloride were disposed of between 1955 and 1973, resulting in extensive soil and groundwater contamination. The VOC-Arid ID schedule has been divided into three phases of implementation. The phased approach provides for: rapid transfer of technologies to the Environmental Restoration (EM-40) programs once demonstrated; logical progression in the complexity of demonstrations based on improved understanding of the VOC problem; and leveraging of the host site EM-40 activities to reduce the overall cost of the demonstrations. During FY92 and FY93, the primary technology demonstrations within the ID were leveraged with an ongoing expedited response action at the Hanford 200 West Area, which is directed at vapor extraction of VOCs from the vadose (unsaturated) zone. Demonstration efforts are underway in the areas of subsurface characterization including: drilling and access improvements, off-gas and borehole monitoring of vadose zone VOC concentrations to aid in soil vapor extraction performance evaluation, and treatment of VOC-contaminated off-gas. These current demonstration efforts constitute Phase 1 of the ID and, because of the ongoing vadose zone ERA, can result in immediate transfer of successful technologies to EM-40

  5. Machine learning for predicting soil classes in three semi-arid landscapes

    Science.gov (United States)

    Brungard, Colby W.; Boettinger, Janis L.; Duniway, Michael C.; Wills, Skye A.; Edwards, Thomas C.

    2015-01-01

    Mapping the spatial distribution of soil taxonomic classes is important for informing soil use and management decisions. Digital soil mapping (DSM) can quantitatively predict the spatial distribution of soil taxonomic classes. Key components of DSM are the method and the set of environmental covariates used to predict soil classes. Machine learning is a general term for a broad set of statistical modeling techniques. Many different machine learning models have been applied in the literature and there are different approaches for selecting covariates for DSM. However, there is little guidance as to which, if any, machine learning model and covariate set might be optimal for predicting soil classes across different landscapes. Our objective was to compare multiple machine learning models and covariate sets for predicting soil taxonomic classes at three geographically distinct areas in the semi-arid western United States of America (southern New Mexico, southwestern Utah, and northeastern Wyoming). All three areas were the focus of digital soil mapping studies. Sampling sites at each study area were selected using conditioned Latin hypercube sampling (cLHS). We compared models that had been used in other DSM studies, including clustering algorithms, discriminant analysis, multinomial logistic regression, neural networks, tree based methods, and support vector machine classifiers. Tested machine learning models were divided into three groups based on model complexity: simple, moderate, and complex. We also compared environmental covariates derived from digital elevation models and Landsat imagery that were divided into three different sets: 1) covariates selected a priori by soil scientists familiar with each area and used as input into cLHS, 2) the covariates in set 1 plus 113 additional covariates, and 3) covariates selected using recursive feature elimination. Overall, complex models were consistently more accurate than simple or moderately complex models. Random

  6. Vegetation of semi-stable rangeland dunes of the Navajo Nation, Southwestern USA

    Science.gov (United States)

    Thomas, Kathryn A.; Redsteer, Margaret H.

    2016-01-01

    Dune destabilization and increased mobility is a worldwide issue causing ecological, economic, and health problems for the inhabitants of areas with extensive dune fields. Dunes cover nearly a third of the Navajo Nation within the Colorado Plateau of southwestern USA. There, higher temperatures and prolonged drought beginning in 1996 have produced significant increases in dune mobility. Vegetation plays an important role in dune stabilization, but there are few studies of the plants of the aeolian surfaces of this region. We examined plant species and their attributes within a moderately vegetated dune field of the Navajo Nation to understand the types and characteristics of plants that stabilize rangeland dunes. These dunes supported a low cover of mixed grass-scrubland with fifty-two perennial and annual species including extensive occurrence of non-native annual Salsola spp. Perennial grass richness and shrub cover were positively associated with increased soil sand composition. Taprooted shrubs were more common on sandier substrates. Most dominant grasses had C4 photosynthesis, suggestive of higher water-use efficiencies and growth advantage in warm arid environments. Plant cover was commonly below the threshold of dune stabilization. Increasing sand movement with continued aridity will select for plants adapted to burial, deflation, and abrasion. The study indicates plants tolerant of increased sand mobility and burial but more investigation is needed to identify the plants adapted to establish and regenerate under these conditions. In addition, the role of Salsola spp. in promoting decline of perennial grasses and shrubs needs clarification.

  7. Rainwater harvesting in arid and semi-arid zones (repr. 1997)

    OpenAIRE

    Boers, Th.M.

    1994-01-01

    In arid and semi-arid regions, the scarcity of water can be alleviated by rainwater harvesting, which is defined as a method of inducing, collecting, storing, and conserving local surface runoff for agriculture. Rainwater harvesting can be applied with different systems, and this dissertation deals with the system of micro-catchments. A microcatchment consists of a runoff area and a basin area in which a tree is planted. The purpose of this study was to develop a design procedure for micro-ca...

  8. Millennial-scale records of North American Monsoon in time and space during the last glacial period: reconstructions from arid northern Mexico

    Science.gov (United States)

    Roy, P.; Quiroz-Jiménez, D.; Charles-Polo, M.; Lozano-Santacruz, R.

    2013-05-01

    The arid northern Mexico is part of the Sonora and Chihuahua Deserts and both the deserts belong to the North American Desert system. The North American Monsoon (NAM) or Mexican Monsoon refers to the system that brings summer precipitation to arid northern Mexico and southwestern USA. It contributes ca. 70-80% of total annual precipitation along the western slopes of the Sierra Madre Occidental (northern Mexico) and ca. 40-50% of total precipitation in Arizona and New Mexico (southwest USA). High-resolution geochemical data from lacustrine deposits located between 23°N and 31°N (paleolakes La Salada, Babicora and San Felipe) provide spatio-temporal and millennial-scale paleohydrological records related to the dynamics of summer precipitation as well as westerly winter storms over the last glacial period. The inverse relationship between proxy records of runoff into lacustrine basins of northern Mexico and winter precipitation over the southwestern USA indicate that the westerly winter storms had minimal influence south of 30°N and the paleohydrological changes are mainly summer precipitation controlled. The variation in summer season precipitation between 20 and 60 cal. kyr BP was driven by long term changes in summer insolation. During an interval of lower summer insolation (i.e. >60 cal. kyr BP), the higher summer precipitation could be related to the NAM expansion as a result of reduced north hemisphere ice sheets. On a millennial-scale, the region received more than average precipitation during the warm interstadials and vice versa.

  9. Systematic revision of the marbled velvet geckos (Oedura marmorata species complex, Diplodactylidae) from the Australian arid and semi-arid zones.

    Science.gov (United States)

    Oliver, Paul M; Doughty, Paul

    2016-03-08

    Lizards restricted to rocky habitats often comprise numerous deeply divergent lineages, reflecting the disjunct nature of their preferred habitat and the capacity of rocky habitats to function as evolutionary refugia. Here we review the systematics and diversity of the predominantly saxicoline Australian marbled velvet geckos (genus Oedura) in the Australian arid and semi-arid zones using newly-gathered morphological data and previously published genetic data. Earlier work showed that four largely allopatric and genetically divergent lineages are present: Western (Pilbara and Gascoyne regions), Gulf (west and south of the Gulf of Carpentaria), Central (central ranges) and Eastern (Cooper and Darling Basins). None of these four populations are conspecific with true O. marmorata, a seperate species complex that is restricted to the Top End region of the Northern Territory. Top End forms share a short, bulbous tail whereas the other four lineages treated here possess a long, tapering tail. Morphological differences among the arid and semi-arid lineages include smaller body size, tapering lamellae and a shorter tail for the Gulf population, and a partially divided rostral scale in the Western population compared to the Central and Eastern populations. Accordingly, we resurrect O. cincta de Vis from synonymy for the Central and Eastern lineages, and regard this species as being comprised of two evolutionary significant units. We also describe the Gulf and Western lineages as new species: Oedura bella sp. nov. and O. fimbria sp. nov., respectively. We note that a predominantly arboreal lineage (the Eastern lineage of O. cincta) is more widely distributed than the other lineages and is phylogenetically nested within a saxicoline clade, but tends to have a deeper head and shorter limbs, consistent with morphological variation observed in other lizard radiations including both saxicoline and arboreal taxa.

  10. Analysis list: ARID1A [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ARID1A Liver + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ARID1A.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/hg19/target/ARID1A.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/AR...ID1A.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ARID1A.Liver.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Liver.gml ...

  11. Analysis list: ARID1B [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ARID1B Liver + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ARID1B.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/hg19/target/ARID1B.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/AR...ID1B.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ARID1B.Liver.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Liver.gml ...

  12. Analysis list: ARID3B [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ARID3B Others + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ARID3B.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/hg19/target/ARID3B.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/AR...ID3B.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ARID3B.Others.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Others.gml ...

  13. Analysis list: ARID2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ARID2 Liver + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ARID2.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/hg19/target/ARID2.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/AR...ID2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ARID2.Liver.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Liver.gml ...

  14. Phylogeography of the arid-adapted Malagasy bullfrog, Laliostoma labrosum, influenced by past connectivity and habitat stability.

    Science.gov (United States)

    Pabijan, Maciej; Brown, Jason L; Chan, Lauren M; Rakotondravony, Hery A; Raselimanana, Achille P; Yoder, Anne D; Glaw, Frank; Vences, Miguel

    2015-11-01

    The rainforest biome of eastern Madagascar is renowned for its extraordinary biodiversity and restricted distribution ranges of many species, whereas the arid western region of the island is relatively species poor. We provide insight into the biogeography of western Madagascar by analyzing a multilocus phylogeographic dataset assembled for an amphibian, the widespread Malagasy bullfrog, Laliostoma labrosum. We find no cryptic species in L. labrosum (maximum 1.1% pairwise genetic distance between individuals in the 16S rRNA gene) attributable to considerable gene flow at the regional level as shown by genetic admixture in both mtDNA and three nuclear loci, especially in central Madagascar. Low breeding site fidelity, viewed as an adaptation to the unreliability of standing pools of freshwater in dry and seasonal environments, and a ubiquitous distribution within its range may underlie overall low genetic differentiation. Moreover, reductions in population size associated with periods of high aridity in western Madagascar may have purged DNA variation in this species. The mtDNA gene tree revealed seven major phylogroups within this species, five of which show mostly non-overlapping distributions. The nested positions of the northern and central mtDNA phylogroups imply a southwestern origin for all extant mtDNA lineages in L. labrosum. The current phylogeography of this species and paleo-distributions of major mtDNA lineages suggest five potential refugia in northern, western and southwestern Madagascar, likely the result of Pleistocene range fragmentation during drier and cooler climates. Lineage sorting in mtDNA and nuclear loci highlighted a main phylogeographic break between populations north and south of the Sambirano region, suggesting a role of the coastal Sambirano rainforest as a barrier to gene flow. Paleo-species distribution models and dispersal networks suggest that the persistence of some refugial populations was mainly determined by high population

  15. Preparing a Schematic Soils Map of an Arid Area Using Landsat Imagery

    OpenAIRE

    Gilbert, R. H.

    1980-01-01

    Between June 1977 and October 1979, a schematic soils map was made of an arid area 2,149,700 square kilometers in size using photo-interpretive techniques on 120 Landsat scenes. The smallest mapping unit was about 5000 hectares. The mapping units were named for the soil subgroups that were present classification of the soils was based on Soil Taxonomy. Visual interpretations were made on the images (black and white band 7) after determining the general landscape forms that were present in ...

  16. Southwestern Power Administration site environmental report for calendar year 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    During CY 93, Southwestern was not involved in any programs that had a direct effect on the environment, involving endangered species, protection of wetlands, or increased electromagnetic radiation. Southwestern continued to function throughout the year in an operations and maintenance posture with minor substation projects. Southwestern received an environmental management audit by the Department of Energy`s Office of Environmental Audit (EH-24), during CY 1992. The purpose of the audit was to give Southwestern, DOE headquarters, and the Secretary an indication of the status of Southwestern management`s effectiveness in discharging its duties in an environmentally responsible manner. The audit identified 17 findings. An action plan was developed and remediation of the findings has been accomplished. Several strengths were identified during the audit with regard to the environmental programs at Southwestern. Most importantly, senior management at Southwestern has taken actions to increase environmental awareness throughout the organization which is evidenced by the creation of the Environmental, Safety, Health, and Security Office.

  17. Isotope and radiation techniques for efficient water and fertilizer use in semi-arid regions

    International Nuclear Information System (INIS)

    The Joint FAO/IAEA Division carried out a coordinated research programme, which was concerned with the efficiency of water and fertilizer uses in semi-arid farming systems. The present publication is a summary of the individual contributions from Belgium, Chile, Ivory Coast, Cyprus, France, India, Israel, Romania, Senegal, Sri Lanka and the United States of America, over the period 1978-1984. Water and fertilizer uptake by crops are dynamic processes affected by several factors of the soil-plant-atmosphere system. The neutron moisture meters were used not only to measure soil water contents but also to understand water dynamics under field conditions. Nitrogen is the most limiting nutrient in many semi-arid regions, and as its absorption is very much related to water dynamics in the soil, experiments using N-15 labelled fertilizer were carried out, which are presented in this report

  18. Energy map of southwestern Wyoming, Part A - Coal and wind

    Science.gov (United States)

    Biewick, Laura R.H.; Jones, Nicholas R.

    2012-01-01

    To further advance the objectives of the Wyoming Landscape Conservation Initiative (WLCI) the U.S. Geological Survey (USGS) and the Wyoming State Geological Survey (WSGS) have compiled Part A of the Energy Map of Southwestern Wyoming. Focusing primarily on electrical power sources, Part A of the energy map is a compilation of both published and previously unpublished coal (including coalbed gas) and wind energy resources data, presented in a Geographic Information System (GIS) data package. Energy maps, data, documentation and spatial data processing capabilities are available in a geodatabase, published map file (pmf), ArcMap document (mxd), Adobe Acrobat PDF map (plate 1) and other digital formats that can be downloaded at the USGS website. Accompanying the map (plate 1) and the geospatial data are four additional plates that describe the geology, energy resources, and related infrastructure. These tabular plates include coal mine (plate 2), coal field (plate 3), coalbed gas assessment unit (plate 4), and wind farm (plate 5) information with hyperlinks to source publications and data on the internet. The plates can be printed and examined in hardcopy, or accessed digitally. The data represent decades of research by the USGS, WSGS, BLM and others, and can facilitate landscape-level science assessments, and resource management decisionmaking.

  19. Conservation genomics reveals multiple evolutionary units within Bell’s Vireo (Vireo bellii).

    Science.gov (United States)

    Klicka, Luke B.; Kus, Barbara E.; Title, Pascal O.; Burns, Kevin J.

    2016-01-01

    The Bell’s Vireo (Vireo bellii) is a widespread North American species of bird that has declined since the mid-1960s primarily due to habitat modification. Throughout its range, Bell’s Vireo populations are regulated under varying degrees of protection; however, the species has never been characterized genetically. Therefore, the current taxonomy used to guide management decisions may misrepresent the true evolutionary history for the species. We sequenced 86 individuals for ND2 and genotyped 48 individuals for genome-wide SNPs to identify distinct lineages within Bell’s Vireo. Phylogenetic analyses uncovered two distinct clades that are separated in the arid southwestern United States, near the border of the Chihuahuan and Sonoran Deserts. These clades diverged from each other approximately 1.11–2.04 mya. The timing of diversification, geographic location, and niche modeling of the east/west divergence suggest vicariance as a mode of diversification for these two lineages. Analyses of the SNP dataset provided additional resolution and indicated the Least Bell’s Vireo populations are a distinct evolutionary lineage. Our genetic evidence, together with information from morphology and behavior, suggests that the Bell’s Vireo complex involves two species, each containing two separate subspecies. This new information has implications for the federal, state and other listing status of Bell’s Vireo throughout its range.

  20. A PROPOSED NEW VEGETATION INDEX, THE TOTAL RATIO VEGETATION INDEX (TRVI), FOR ARID AND SEMI-ARID REGIONS

    OpenAIRE

    H. Fadaei; Suzuki, R.; Sakai, T; Torii, K.

    2012-01-01

    Vegetation indices that provide important key to predict amount vegetation in forest such as percentage vegetation cover, aboveground biomass, and leaf-area index. Arid and semi-arid areas are not exempt of this rule. Arid and semi-arid areas of northeast Iran cover about 3.4 million ha and are populated by two main tree species, the broadleaf Pistacia vera (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environ...

  1. Assessing Water Management Impacts of Climate Change for a semi-arid Watershed in the Southwestern US

    Science.gov (United States)

    Rajagopal, S.; Dominguez, F.; Gupta, H. V.; Castro, C. L.; Troch, P. A.

    2011-12-01

    Water managers for the City of Phoenix currently face the need to make informed policy decisions regarding long-term impacts of climate change on the Salt-Verde River basin in central Arizona. To provide a scientifically informed basis for this, we estimate the evolution of important components of the basin-scale water balance through the end of the 21st century. Bias-corrected and spatially downscaled climate projections from the Phase-3 Coupled Model Intercomparison Project of the World Climate Research Programme were used to drive a spatially distributed variable infiltration capacity model of the hydrologic processes in the basins. Of the Global Climate Model's participating in the IPCC fourth assessment we selected a five-model ensemble, including the three that best reproduce the historical climatology for our study region, plus two others to represent wetter and drier than model average conditions; the latter two were requested by City of Phoenix water managers to more fully represent the full range of GCM prediction uncertainty. For each GCM, data for three emission scenarios (A1B, A2, B1) was used to drive the hydrologic model into the future. The model projections indicate a 25% statistically significant decrease in streamflow by the end of the 21st century. This is primarily caused by decreased winter precipitation accompanied by significant (temperature driven) reductions in storage of snow. From the analysis of the future period, a synthetic climate dataset was created to reflect future changes in magnitude while preserving the correlation by perturbing the historical observed precipitation and temperature. This dataset was used to evaluate climate elasticity and improve water managers understanding of the impacts to the basin. The results shown in this presentation clearly indicate the manner in which water management in central Arizona is likely to be impacted by changes in regional climate.

  2. Southwestern Institute of Physics: Annual Report 1998

    International Nuclear Information System (INIS)

    The main achievements of controlled nuclear fusion research are presented for Southwestern Institute of Physics in 1998 year. With the establishment and operation of two auxiliary heating systems (NBI, ICRH), the HL-1M Tokamak is equipped with main auxiliary heating and current driving systems such as NBI, ECRH, ICRH and LHCD etc. . In addition, a variety of advanced fueling system, i.e. , multi-shot pellet and supersonic molecular beam injection, the first wall processing technologies of boronization, siliconization and lithiumization as well as more than 20 diagnostic facilities with partial space-time resolution capability have been established on the device. The construction of a larger Tokamak with divertors, the HL-2A, and its complementary systems are being carried out

  3. Remote Sensing Parameterization of Land Surface Heat Fluxes over Arid and Semi-arid Areas

    Institute of Scientific and Technical Information of China (English)

    马耀明; 王介民; 黄荣辉; 卫国安; MassimoMENENTI; 苏中波; 胡泽勇; 高峰; 文军

    2003-01-01

    Dealing with the regional land surfaces heat fluxes over inhomogeneous land surfaces in arid and semi-arid areas is an important but not an easy issue. In this study, one parameterization method based on satellite remote sensing and field observations is proposed and tested for deriving the regional land surface heat fluxes over inhomogeneous landscapes. As a case study, the method is applied to the Dunhuang experimental area and the HEIFE (Heihe River Field Experiment, 1988-1994) area. The Dunhuang area is selected as a basic experimental area for the Chinese National Key Programme for Developing Basic Sciences: Research on the Formation Mecbanism and Prediction Theory of Severe Climate Disaster in China (G1998040900, 1999-2003). The four scenes of Landsat TM data used in this study are 3 June 2000,22 August 2000, and 29 January 2001 for the Dunhuang area and 9 July 1991 for the HEIFE area. The regional distributions of land surface variables, vegetation variables, and heat fluxes over inhomogeneous landscapes in arid and semi-arid areas are obtained in this study.

  4. Environmental Assessment for power marketing policy for Southwestern Power Administration

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    Southwestern Power Administration (Southwestern) needs to renew expiring power sales contracts with new term (10 year) sales contracts. The existing contracts have been in place for several years and many will expire over the next ten years. Southwestern completed an Environmental Assessment on the existing power allocation in June, 1979 (a copy of the EA is attached), and there are no proposed additions of any major new generation resources, service to discrete major new loads, or major changes in operating parameters, beyond those included in the existing power allocation. Impacts from a no action plan, proposed alternative, and market power for less than 10 years are described.

  5. Environmental Assessment for power marketing policy for Southwestern Power Administration

    International Nuclear Information System (INIS)

    Southwestern Power Administration (Southwestern) needs to renew expiring power sales contracts with new term (10 year) sales contracts. The existing contracts have been in place for several years and many will expire over the next ten years. Southwestern completed an Environmental Assessment on the existing power allocation in June, 1979 (a copy of the EA is attached), and there are no proposed additions of any major new generation resources, service to discrete major new loads, or major changes in operating parameters, beyond those included in the existing power allocation. Impacts from a no action plan, proposed alternative, and market power for less than 10 years are described

  6. Warm-dry collocation of recent drought in southwestern China tied to moisture transport and climate warming

    Institute of Scientific and Technical Information of China (English)

    戴新刚; 柳晔; 汪萍

    2015-01-01

    This study aims to investigate the recent drought in southwestern China and its association with environmental changes in moisture transport (MT) and atmospheric circulation. Climatic Research Unit grid data, in situ observations in China, and ERA-interim reanalysis are used to study the characteristics of the drought and the associated mechanism. Recent precipitation trends show a pattern of “Northern wetting and Southern drying”, similar to the anti-phase of the climate pattern prevailing during 1980–2000 in mainland China;southwestern China incurred a severe drought during 2009–2013. Wavelet analysis reveals that the drought coincides with a warm–dry phase of temperature and precipitation on a period of about 20 years and beyond 100 years, where contributions account for 43%and 57%of the deficiency of the precipitation, averaged for 2003–2012, respectively. A further investigation reveals that the drought results chiefly from the decline of the southwestern monsoon MT toward southwestern China, in addition to mid-latitude circulation changes, which leads to more blockings near the Ural Mountains and the Sea of Okhotsk in the rainy season and negative anomalies around Lake Baikal and northeast China in the dry season. These anomalies are likely to be correlated with global sea surface temperature changes and need to be studied further.

  7. Incidence of retinopathy of prematurity and risk factors in the South-Western Region of Iran

    OpenAIRE

    Mostafa Feghhi; Seyed Mohammad Hassan Altayeb; Foad Haghi; Ali Kasiri; Fereydoun Farahi; Mosoud Dehdashtyan; Mahzyar Movasaghi; Fakher Rahim

    2012-01-01

    Aims: The aim of this study was to report the incidence of retinopathy of prematurity (ROP) and the contribution of various risk factors to ROP in the south-western region of Iran. Material and Methods: This cross-sectional case-control series reviewed all low birth weight (LBW, ≤2000 g) neonates and/or neonates less than 32 weeks gestational age who had been hospitalized in the Neonatal Intensive Care Unit from 2006 to 2010. The cohort was divided into infants without ROP (nonROP group)...

  8. Seasonal precipitation and soil moisture recharge as competing drivers of carbon and water fluxes across a gradient of semi-arid ecosystems

    Science.gov (United States)

    Maurer, G. E.; Litvak, M. E.

    2015-12-01

    Ecosystems of the southwestern U.S. receive precipitation in two prevailing weather patterns, the convective monsoon storms prevalent in late summer months, and synoptic-scale storm systems that are most frequent in late fall and winter. We examined a seven year record of eddy covariance data from six ecosystem types along an elevation/aridity gradient in the southwestern U.S. to determine the degree to which CO2 and H2O fluxes correlate with seasonal and interannual patterns in precipitation and soil water availability. Our results show that the majority of total annual primary production (GPP), ecosystem respiration (Reco), and evapotranspiration (ET) occurred during the monsoon season at most sites and in most years. During spring, typically the driest period in this region, the sites frequently had high rates of GPP and comparatively low Reco and ET, meaning this time period is important for annual carbon sequestration. Correlation between seasonal productivity measures and precipitation are generally weak, suggesting that some productivity peaks, such as the one in spring, are supported by stored soil water. We estimated the size of available soil water pools at multiple depths using extensive measurements of soil volumetric water content. Preliminary findings show strong relationships between seasonal CO2 and H2O fluxes and estimated available water in deeper soil layers. Our work indicates that relatively infrequent soil water recharge events are key to understanding the temporal distribution of ecosystem CO2 and H2O fluxes in the southwestern U.S., and potentially in other semi-arid ecosystems.

  9. Prevalence of Dental Caries and Periodontal Disease in Mexican American Children Aged 5 to 17 Years: Results from Southwestern HHANES, 1982-83.

    Science.gov (United States)

    Ismail, Amid L.; And Others

    1987-01-01

    Dental caries and periodontal disease in Mexican American children of the southwestern United States occur mainly in molars, lending strong support for the use of fissure sealants as a preventive procedure. This study also reports on the prevalence of fillings decay and gingivitis in this population. (VM)

  10. College-Bound Seniors, 1979. [College Board ATP Summary Reports for: National, New England, Middle States, Southern, Midwestern, Southwestern, Rocky Mountain, and Western Regions.

    Science.gov (United States)

    College Entrance Examination Board, Princeton, NJ.

    The Admissions Testing Program (ATP) is a service of the College Board. The 1979 ATP summary reports on college-bound seniors were produced for each region of the United States, including New England, the Middle, Southern, Midwestern, Southwestern, Rocky Mountain, and Western States. The national and each regional report are in separate booklets.…

  11. Late Holocene climate variability in the southwestern Mediterranean region: an integrated marine and terrestrial geochemical approach

    Directory of Open Access Journals (Sweden)

    C. Martín-Puertas

    2010-12-01

    Full Text Available A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G and terrestrial (Zoñar Lake, Andalucia, Spain geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP – synchronously to the global aridity crisis of the third-millennium BC – and during the Medieval Climate Anomaly (1.4–0.7 cal ka BP. Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean.

  12. Hydrology of Salt Wells Creek : a plains stream in southwestern Wyoming

    Science.gov (United States)

    Lowham, H.W.; DeLong, L.L.; Collier, K.R.; Zimmerman, E.A.

    1982-01-01

    Development of energy minerals in plains areas of Wyoming is expanding rapidly. Such development may affect water resources and hydrologic relations of the plains; however, little information exists concerning hydrologic processes for these areas. This report summarizes results of a hydrologic study made during 1975-78 of Salt Wells creek, a drainage area of about 500 square miles located southeast of Rock Springs, Wyoming. The area is typical of arid and semiarid plains areas in southwestern Wyoming where mineral development is occurring. Salt Wells Creek is predominately an intermittent stream. Numerous springs in the headwaters cause small perennial flows in some upstream tributaries, but evaporation, freezeup, and seepage deplete these flows so that the middle and lower reaches of the main channel have only intermittent flows. The intermittent nature of streamflow affects water quality. It was observed that a flushing of dissolved solids and suspended sediment occurs during the first flows of a runoff event. A striking feature of the stream is its deeply incised channel. The downcutting is attributed to the cummulative effects of: (1) a change in the relative climate, amounts of annual precipitation occurring as rain and snow, (2) change in base level due to downstream channelization, and (3) changes in land use. Because of the incision, erosion is now expanding to include intervening tributaries. (USGS)

  13. Paleozoic lithofacies in southwestern Sinai and their depositional environments

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D.P.; Peck, N.R.; Mansour, S.E.

    1983-03-01

    Major breaks in sedimentation, accompanied by well-developed paleosols, have been successfully used to subdivide the 600 m (1968 ft) of Paleozoic sandstone and shale sequence of southwestern Sinai, Egypt, into five smaller facies association units (i.e., formations). The lowest unit (the Araba Formation) is dominated by 1 to 10 m (3 to 32 ft) thick coarsening-up sequences of parallel-bedded, varicolored, fine-grained arkosic sandstone and muddy sandstone. This is the deposit of a low-energy prograding sandy coastal plain complex that grades upward into a thin, fining-up channel-overbank deposits with poorly developed paleosols. The overlying Naqus Formation scours deep into the Araba, and is characterized by lenticular, coarse to medium-grained, cross-bedded quartz sandstone with only a few clayey intervals. Cross-beds are common. The Naqus is interpreted as alluvial fanbraided stream deposits. A 15 to 20 m (40 to 66 ft) thick, conspicuous dark brown, ferruginous shale, ochre-yellow dolomitic sandstone and fossiliferous gray siltstone sequence, persistent all along the Qabeliat valley, overlies the Naqus and represents lagoonal deposits laterally equivalent to the shallow marine shale-dolomite sequence of the Um Bogma Formation farther north. Basal fluvial channel sands of the succeeding Ataqa Formation cut into the Um Bogma paleosol, and grade upward into the fossiliferous green-red marine shales and subordinate sandstones in shoaling-upward sequences. Southward in the Qabeliat valley, a parallel-bedded sequence of thick green shales and thin brown sandstones, both nonfossiliferous, intervenes in the middle of the Budra Formation and represents ephemeral lake deposits related to the fluvial system.

  14. Drowning in children: Aseer Central Hospital experience, Southwestern Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Suliman H Al-Fifi

    2011-01-01

    Full Text Available Aim: To study the reasons, magnitude and outcome of drowning following submersion in water of children admitted to the Pediatric Intensive Care Unit in Aseer Province, Saudi Arabia. Materials and Methods: A retrospective cohort study of all pediatric patients (0-13 years old who drowned and were admitted to the Pediatric Intensive Care Unit, Aseer Central Hospital, Southwestern Saudi Arabia, between January 1st 1999 and December 31st 2009. Results: A total of 19 cases were admitted following submersion in water. The mean age was 5.2 years ±3.8. Majority of victims (94.1% were from the highland areas. Events most frequently occurred in the summer (46.7%, followed by spring and winter, 33.3% and 20%, respectively. Home events constituted 44.4% of submersion cases. Of these, 55.6% drowned in a washing container, While 53.4% submersed in swimming pools. Twenty-two percent of these accidents occurred in the sea and in wells while 11.1% occurred in a lake. The mean duration of submersion was 4.04 minutes ± 5.35. Cardiac arrest was reported upon arrival at hospital in 42.1% of the victims. There were seven deaths (36.8 % and in one patient (5.2 % there was severe brain injury. In all deceased cases, no adults were watching the children when the accidents occurred. Conclusion: Drowning is a significant risk factor facing our children and can claim lives. The media as well as the authority should play a major role in increasing the public awareness to minimize or prevent such a problem.

  15. Uses of tree legumes in semi-arid regions

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.

    1980-01-01

    Uses of tree legumes in semi-arid and arid regions are reviewed. This review is divided into sections according to the following general use categories: fuels; human food; livestock food; to increase yields of crops grown beneath their canopies;and control of desertification. (MHR)

  16. CHARACTERISTICS AND CONSTRUCTION OF LANDSCAPE???ECOLOGY IN ARID REGIONS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper analyzes the characteristics of the landscape structures and landacape ecological processes in arid regions of China. Landscape structure is simplicity and homogeneity with the pattern of desert-oasis-river and canal corridor. The spatial distribution of landscape heterogeneity mosaics is relatively dependent on water resources. In arid regions,the landscape changes rapidly and extensively because of the sensitive landscape ecosystems and fragile regional ecosystems.For the sustainable development of arid regions, the theories and methods for the eco-environmental construction and the strategies of ecological construction in the arid regions were proposed in the view of landscape ecology. Keynote subjects of landscape ecology were also discussed. The paper points out that protecting and increasing landscape diversity and heterogeneity are critical to control ecological safety in arid regions.

  17. Analysis list: ARID3A [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ARID3A Blood,Liver + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/AR...ID3A.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ARID3A.5.tsv http://dbarchive.biosciencedb...c.jp/kyushu-u/hg19/target/ARID3A.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ARID3A.Blood.tsv,http://dbarchive.biosci...encedbc.jp/kyushu-u/hg19/colo/ARID3A.Liver.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Liver.gml ...

  18. Environmental scanning strategy of manufacturing companies in Southwestern Nigeria

    OpenAIRE

    Olamade, O. O.; Oyebisi, T. O.; Egbetokun, A. A.; Adebowale, B. O.

    2009-01-01

    In this paper, we examine the environmental scanning strategy of manufacturing companies in Southwestern Nigeria against the background that manufacturing companies in Nigeria exist in a challenging environment characterised by high import dependency, inappropriate policies, lack of transparent governance and weak industrial capabilities. Empirical data was collected with a questionnaire from a sample of 84 manufacturing firms in Southwestern Nigeria. We found that generally, companies in the...

  19. The current bioenergy production potential of semi-arid and arid regions in sub-Saharan Africa

    NARCIS (Netherlands)

    Wicke, B.; Smeets, E.M.W.; Watson, H.; Faaij, A.P.C.

    2011-01-01

    This article assesses the current technical and economic potential of three bioenergy production systems (cassava ethanol, jatropha oil and fuelwood) in semi-arid and arid regions of eight sub-Saharan African countries. The results indicate that the availability of land for energy production ranges

  20. Assessment of the desertification vulnerability of the Cappadocian district (Central Anatolia, Turkey based on aridity and climate-process system

    Directory of Open Access Journals (Sweden)

    Murat Türkeş

    2011-03-01

    Full Text Available The present study discusses climate of the Cappadocian district in Turkey on the basis of Thornthwaite’s climate classification and water budget, Erinç’s aridity index and United Nations Convention to Combat Desertification (UNCCD aridity index, along with the spatial and inter-seasonal variations of precipitation and air temperatures. Vulnerability of the Cappadocia to desertification processes was also investigated with respect to the aridity, lithology dominated by tuffs and climate-process system and present land-use features of the district. The data analysis revealed that coefficients of variation (CV of the mean and maximum temperatures are the greatest in summer and the smallest in winter. Nevşehir and Kayseri environs are the most continental parts of the Cappadocia with a high inter-annual variability and low temperatures. Cappadocia is characterized with a continental rainfall regime having a maximum precipitation in spring. Variability of summer precipitation totals is greater than that of other seasons, varying from 65.7% to 78%. The CVs of the annual precipitation totals are about 18% at north and about 20% at south. Semi-arid and dry sub-humid or semi-humid climate types prevail over Cappadocia according to Thornthwaite’s moisture and Erinç’s aridity indices. Steppe is the dominant vegetation formation with sparse dry trees. The Cappadocia is vulnerable to the desertification processes due to both natural factors (e.g. degree of aridity, climate-process system, weathering of tuffs, erosion, climate change, etc. and human-involvement (e.g. land degradation and intensive tourism, etc.. In order to mitigate desertification and to preserve the historical and cultural heritages in Cappadocia, sustainable land-use management and tourism planning applications are urgently needed.

  1. Assessment of the desertification vulnerability of the Cappadocian district (Central Anatolia, Turkey based on aridity and climate-process system

    Directory of Open Access Journals (Sweden)

    Murat Türkeş

    2011-03-01

    Full Text Available The present study discusses climate of the Cappadocian district in Turkey on the basis of Thornthwaite’s climate classification and water budget, Erinç’s aridity index and United Nations Convention to Combat Desertification (UNCCD aridity index, along with the spatial and inter-seasonal variations of precipitation and air temperatures. Vulnerability of the Cappadocia to desertification processes was also investigated with respect to the aridity, lithology dominated by tuffs and climate-process system and present land-use features of the district. The data analysis revealed that coefficients of variation (CV of the mean and maximum temperatures are the greatest in summer and the smallest in winter. Nevşehir and Kayseri environs are the most continental parts of the Cappadocia with a high inter-annual variability and low temperatures. Cappadocia is characterized with a continental rainfall regime having a maximum precipitation in spring. Variability of summer precipitation totals is greater than that of other seasons, varying from 65.7% to 78%. The CVs of the annual precipitation totals are about 18% at north and about 20% at south. Semi-arid and dry sub-humid or semi-humid climate types prevail over Cappadocia according to Thornthwaite’s moisture and Erinç’s aridity indices. Steppe is the dominant vegetation formation with sparse dry forests. The Cappadocia is vulnerable to the desertification processes due to both natural factors (e.g. degree of aridity, climate-process system, weathering of tuffs, erosion, climate change, etc. and human-involvement (e.g. land degradation and intensive tourism, etc.. In order to mitigate desertification and to preserve the historical and cultural heritages in Cappadocia, sustainable land-use management and tourism planning applications are urgently needed.

  2. Determine the optimum spectral reflectance of juniper and pistachio in arid and semi-arid region

    Science.gov (United States)

    Fadaei, Hadi; Suzuki, Rikie

    2012-11-01

    Arid and semi-arid areas of northeast Iran cover about 3.4 million ha are populated by two main tree species, the broadleaf Pistacia vera. L (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environmentally important but genetically essential as seed sources for pistachio production in orchards. In this study, we estimated the optimum spectral reflectance of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. In this research spectral reflectance are able to specify of multispectral from Advanced Land Observing Satellite (ALOS) that provided by JAXA. These data included PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, has one band with a wavelength of 0.52-0.77 μm and AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, has four multispectral bands: blue (0.42-0.50 μm), green (0.52-0.60 μm), red (0.61-0.69 μm), and near infrared (0.76-0.89 μm). Total ratio vegetation index (TRVI) of optimum spectral reflectance of juniper and pistachio have been evaluated. The result of TRVI for Pistachio and juniper were (R2= 0.71 and 0.55). I hope this research can provide decision of managers to helping sustainable management for arid and semi-arid regions in Iran.

  3. Acupunctural Afforestation for Desertification Mitigation over Semi-Arid Regions in East Asia

    Science.gov (United States)

    Myoung, B.; Choi, Y.; Park, S. K.

    2011-12-01

    Desertification over the arid/semi-arid regions in East Asia and dust transports from the regions have been serious concerns for the societies not only in adjacent Asian countries but also in the western US. One of the strategies for desertification mitigation is tree planting over the semi-arid areas. However, unless the newly planted vegetation changes the feedback characteristics between land-surface and the atmosphere, the impact is not profound and effective for a long time. Here we show afforestation effects on the coupling strength between the land-surface and atmosphere, measured by the monthly anomalies of precipitation and evapotranspiration. The coupling strength is an important parameter to diagnose the aridity of a region since the stronger coupling strength is indicative of the higher vulnerability of the local climate to droughts. Simulations of a regional vegetation-climate coupled model reveal that afforestation substantially modulates local coupling strength mainly through controlling variability of evapotranspiration. The coupling strength decreases most significantly with an increase of unit vegetation fraction over the northern and central China including Manchurian Plains and highly populated areas of Beijing and Tianjin. The coupling characteristics of these regions are expected to reduce the occurrence of extreme weather events such as droughts by alleviating positive responses of the surface to precipitation deficit. Therefore, afforestation concentrated on these regions, which is called "acupunctural afforestation", may most effectively contribute to desertification mitigation than other regions by attenuating mechanisms maintaining warm season droughts. This study suggests that our attention should be paid to understanding the coupling strength between land and the atmosphere for desertification mitigation.

  4. Development of an arid site closure plan

    International Nuclear Information System (INIS)

    This document describes the development of a prototype plan for the effective closure and stabilization of an arid low-level waste disposal site. This plan will provide demonstrated closure techniques for a trench in a disposal site at Los Alamos. The accuracy of modeling soil water storage by two hydrologic models, CREAMS and HELP, was tested by comparing simulation results with field measurements of soil moisture in eight experimental landfill cover systems having a range of well-defined soil profiles and vegetative covers. Regression analysis showed that CREAMS generally represented soil moisture more accurately than HELP simulations. Precautions for determining parameter values for model input and for interpreting simulation results are discussed. A specific example is presented showing how the field-validated hydrologic models can be used to develop a final prototype closure plan. 15 refs., 13 figs., 3 tabs

  5. Southwestern USA Drought over Multiple Millennia

    Science.gov (United States)

    Salzer, M. W.; Kipfmueller, K. F.

    2014-12-01

    Severe to extreme drought conditions currently exist across much of the American West. There is increasing concern that climate change may be worsening droughts in the West and particularly the Southwest. Thus, it is important to understand the role of natural variability and to place current conditions in a long-term context. We present a tree-ring derived reconstruction of regional-scale precipitation for the Southwestern USA over several millennia. A network of 48 tree-ring chronologies from California, Nevada, Utah, Arizona, New Mexico, and Colorado was used. All of the chronologies are at least 1,000 years long. The network was subjected to data reduction through PCA and a "nested" multiple linear regression reconstruction approach. The regression model was able to capture 72% of the variance in September-August precipitation over the last 1,000 years and 53% of the variance over the first millennium of the Common Era. Variance captured and spatial coverage further declined back in time as the shorter chronologies dropped out of the model, eventually reaching 24% of variance captured at 3250 BC. Results show regional droughts on decadal- to multi-decadal scales have been prominent and persistent phenomena in the region over the last several millennia. Anthropogenic warming is likely to exacerbate the effects of future droughts on human and other biotic populations.

  6. Synthetic socioeconomic based domestic wastewater hydrographs for small arid communities

    KAUST Repository

    Elnakar, H.

    2012-06-04

    A model was developed to predict synthetic socioeconomic based domestic wastewater hydrographs for the small arid communities. The model predicts the flow hydrograph for random weekdays and weekends based on the specific socioeconomic characteristics of the community. The main socioeconomic characteristics are the composition of the community, the different user behaviours in using water appliances, and the unit discharges of such appliances. Use patterns of water appliances are assumed to vary for the various members of the community and the type of day. Each community is composed of several social categories such as the employee, working woman, stay home woman, stay home child, students etc. The use patterns account for the stochastic nature of use in terms of number of uses, duration of the use and times of use in the day. Randomly generated hydrographs are generated for weekdays and weekends along with synthetic hydrographs of non-exceedance. The model was verified for a small residential compound in Sharm El Shiekh - Egypt using 11 days of flow measurements performed in summer. The synthetic hydrographs based on assumed water use patterns of the various members of the community compared reasonably with the measured hydrographs. Synthetic hydrographs can be derived for a community under consideration to reflect its socioeconomic conditions and thus can be used to generate probability based peaking factors to be used in the design of sewerage systems pumping facilities, and treatment plants. © 201 WIT Press.

  7. Geothermal technoecosystems and water cycles in arid lands. Information paper

    Energy Technology Data Exchange (ETDEWEB)

    Duffield, C.

    1976-01-01

    Arid lands resource information paper No. 2, 'Exploration and Exploitation of Geothermal Resources in Arid and Semiarid Lands,' first issued in 1973, is now out-of-print. The intent of the present paper was to revise that earlier literature review with its annotated bibliography, by recognizing the unusual developments in this field in the interim, with new geothermal fields discovered, new demands for geothermal energy as an alternative source to more conventional sources, and a number of new publications reflecting accelerated research. The extensive bibliography accompanying this paper was produced by ALIS, and includes over one hundred references prepared by the Office of Arid Lands Studies.

  8. Adaptive wetland management in an uncertain and changing arid environment

    Directory of Open Access Journals (Sweden)

    Rebekah Downard

    2014-06-01

    Full Text Available Wetlands in the arid western United States provide rare and critical migratory bird habitat and constitute a critical nexus within larger social-ecological systems (SES where multiple changing land-use and water-use patterns meet. The Bear River Migratory Bird Refuge in Utah, USA, presents a case study of the ways that wetland managers have created adaptive management strategies that are responsive to the social and hydrological conditions of the agriculture-dominated SES within which they are located. Managers have acquired water rights and constructed infrastructure while cultivating collaborative relationships with other water users to increase the adaptive capacity of the region and decrease conflict. Historically, water management involved diversion and impoundment of water within wetland units timed around patterns of agricultural water needs. In the last 20 years, managers have learned from flood and drought events and developed a long-term adaptive management plan that specifies alternative management actions managers can choose each year based on habitat needs and projected water supply. Each alternative includes habitat goals and target wetland water depth. However, wetland management adapted to agricultural return-flow availability may prove insufficient as population growth and climate change alter patterns of land and water use. Future management will likely depend more on negotiation, collaboration, and learning from social developments within the SES than strictly focusing on water management within refuge boundaries. To face this problem, managers have worked to be included in negotiations with regional water users, a strategy that may prove instructive for other wetland managers in agriculture-dominated watersheds.

  9. Population dynamics of small mammals in semi-arid regions: a comparative study of demographic variability in two rodent species.

    OpenAIRE

    Lima, Mauricio; Stenseth, Nils Chr.; Leirs, Herwig; Jaksic, Fabián M

    2003-01-01

    The seasonally determined demographic structure of two semi-arid rodents, both agricultural pest species (the leaf-eared mouse (Phyllotis darwini) in Chile and the multimammate mouse (Mastomys natalensis) in Tanzania), is analysed using capture-mark-recapture (CMR) statistical models and measures for elasticity (the relative change in the growth rate due to a relative unit change in the parameter of concern) derived from projection linear matrix models. We demonstrate that reproduction and su...

  10. Sensitivity of Southwestern US Mountain Ecosystems to Climate Variability: Interactions Among Forest Dieback, Fire, and Erosion

    Science.gov (United States)

    Allen, C. D.

    2004-12-01

    Millions of hectares in the upland landscapes of the Southwestern United States have been affected by forest dieback and severe fire activity since the late 1990s, a period of ongoing severe drought and unusual warmth. Climate regulates physiological plant stress that can directly cause vegetation mortality, and also influences associated insect outbreak dynamics. Climate also interacts with fuel conditions to drive regional fire activity. Current and historic patterns of forest dieback, fire activity, and erosion are described across landscape gradients in Southwestern mountains, particularly the Jemez Mountains of New Mexico. Methods used include inventory and dating of live and dead woody plants to assess demographic changes through time, long-term (since 1991) measurements of ponderosa pine tree-growth at three sites with dendrometer bands, monitoring of herbaceous vegetation along 3 km of permanent transects since 1991, aerial photograph analyses of insect outbreaks and forest dieback and fire activity, and hydrological measurements of runoff and erosion. Similarities and differences in vegetation dieback and regional fire activity patterns between the current drought and the 1950s (when regional drought last affected the Southwest) are explained by changes in climatic and vegetation conditions. The current climate-induced vegetation dieback and pulse of regional fire activity have strong feedbacks with various key ecosystem processes, including water budgets and soil erosion. For example, severe drought and fire both markedly reduce the surface cover of live plants and dead plant materials ("litter"), triggering nonlinear increases in erosion rates once the connectivity of bare soil patches exceeds critical threshold values, particularly during high-intensity summer rainfall events that characterize the Southwestern summer "monsoon". These observations highlight the magnitude, rapidity, and complexity of climate-induced disturbance processes, and provide an

  11. Wastewater reclamation using discarded reverse osmosis membranes for reuse in irrigation in Djibouti, an arid country.

    Science.gov (United States)

    Awaleh, Mohamed Osman; Ahmed, Moussa Mahdi; Soubaneh, Youssouf Djibril; Hoch, Farhan Bouraleh; Bouh, Samatar Mohamed; Dirieh, Elias Said

    2013-01-01

    The purpose of this paper is to establish the feasibility of recovering discarded reverse osmosis (RO) membranes in order to reduce the salinity of domestic treated wastewater. This study shows that the reuse of RO membranes is of particular interest for arid countries having naturally high mineralized water such as Djibouti. The pilot desalination unit reduces the electrical conductivity, the turbidity and the total dissolved salt respectively at 75-85, 96.7 and 95.4%. The water produced with this desalination unit contains an average of 254 cfu/100 mL total coliforms and 87 cfu/100 mL fecal coliforms. This effluent meets the World Health Organization standards for treated wastewater reuse for agricultural purposes. The annual cost of the desalination unit was evaluated as US $/m(3) 0.82, indicating the relatively high cost of this process. Nevertheless, such processes are required to produce an effluent, with a high reuse potential. PMID:23508163

  12. Integrated Indicators-based Gradation of Cultivated Land Quality in Mountainous Region of Southwestern China

    Institute of Scientific and Technical Information of China (English)

    SHAO Jing'an; WEI Chaofu; XIE Deti; ZHOU Yan

    2006-01-01

    The gradation of cultivated land is to assess the suitability of cultivated land for agricultural production in terms of natural and economic properties of land. It can be used to evaluate sustainability of land use and soil management practices. Formal and informal surveys, Delphi and comprehensive index method are adopted to identify appropriate integrated indicators, and measure the gradation of cultivated land quality. The determination of integrated indicators presents three basic features of cultivated land quality: stable plant productivity, social acceptability and maintenance of environmental quality.Pronounced concentration-dissipation law of total function score value occurs in paddy field units, with three ranges, I.e., 79-68.5, 68.5~59 and 59-51. Total function score value in dryland units mainly ranges from 40 to 70, but slight concentration-dissipation law of each unit is still observed, with four ranges, I.e., 79~68, 68~51, 51~37 and 37~15. Paddy field quality is divided into three gradations, and the scales are 18 220.9 ha, 5410.6 ha and 2890.9 ha. Dryland quality is classified into four gradations, and the scales are 1548.6 ha, 8153.8 ha, 3316.3 ha and 685.2 ha. The total function score value of every gradation unit is conformed to the results of farmers' assessment. Research results meet with the needs of accurate degree of the gradation of cultivated land quality. Integrated indicators-based gradation of cultivated land assessment accords with the characteristics of land resources and human preference in the mountains of southwestern China. This study will be useful to promote the monitoring of cultivated land quality, and to supply fine ground and knowledge for establishing appropriate cultivated land management practices in Southwestern China.

  13. Arid Lands--A Study in Ecological Disaster

    Science.gov (United States)

    Eckholm, Erik

    1977-01-01

    Reports that over-grazing and unsound agricultural practices are increasing the world-wide amount of uninhabitable land. Cites some practices which have been used to successfully reclaim arid land areas. (CP)

  14. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 1: Geological and Geomorphological Overview

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    Based upon Viking Orbiter 1 images of the southwestern portion of the Margaritifer Sinus Quadrangle, the northwestern portion of the Argyre Quadrangle, and a small portion of the southeastern Coprates Quadrangle, three major mountainous of plateau units, seven plains units, and six units related to valley forming processes were identified. The photomosaic is oriented such that it provides good areal coverage of the upper Chryse Trough from Argyre Planitia to just above Margaritifer Chaos as well as of plains units on either side of the Trough. The photomosaic was compiled from Viking Orbiter 1 images ranging in resolution from approximately 150 to 300 meters per pixel printed at a scale of about 1:2,000,000. The characteristics of each geomorphic unit are outlined.

  15. Aridity changes in the Tibetan Plateau in a warming climate

    International Nuclear Information System (INIS)

    Desertification in the Tibetan Plateau (TP) has drawn increasing attention in the recent decades. It has been postulated as a consequence of increasing climate aridity due to the observed warming. This study quantifies the aridity changes in the TP and attributes the changes to different climatic factors. Using the ratio of precipitation to potential evapotranspiration (P/PET) as an aridity index, we used observed meteorological records at 83 stations in the TP to calculate PET using the Penman–Monteith algorithm and the ratio. Spatial and temporal changes of P/PET in 1979–2011 were analyzed. Results show that stations located in the arid and semi-arid northwestern TP are becoming significantly wetter, and half of the stations in the semi-humid eastern TP are becoming drier, though not significantly, in the recent three decades. The aridity change patterns are significantly correlated with the change patterns of precipitation, sunshine duration and diurnal temperature range. Temporal correlations between the annual P/PET ratio and other meteorological variables confirm the significant correlation between aridity and the three variables, with precipitation being the dominant driver of P/PET changes at the interannual time scale. Annual PET are insignificantly but negatively correlated with P/PET in the cold season. In the warm season, however, the correlation between PET and P/PET is significant at the confidence level of 99.9% when the cryosphere near the surface melts. Significant correlation between annual wind speed and aridity occurs in limited locations and months. Consistency in the climatology pattern and linear trends in surface air temperature and precipitation calculated using station data, gridded data, and nearest grid-to-stations for the TP average and across sub-basins indicate the robustness of the trends despite the large spatial heterogeneity in the TP that challenge climate monitoring. (letter)

  16. How Do Biases in General Circulation Models Affect Projections of Aridity and Drought?

    Science.gov (United States)

    Ficklin, D. L.; Abatzoglou, J. T.; Robeson, S. M.; Dufficy, A. L.

    2015-12-01

    Unless corrected, biases in General Circulation Models (GCMs) can affect hydroclimatological applications and projections. Compared to a raw GCM ensemble (direct GCM output), bias-corrected GCM inputs correct for systematic errors and can produce high-resolution projections that are useful for impact analyses. By examining the difference between raw and bias-corrected GCMs for the continental United States, this work highlights how GCM biases can affect projections of aridity (defined as precipitation (P)/potential evapotranspiration (PET)) and drought (using the Palmer Drought Severity Index (PDSI)). At the annual time scale for spatial averages over the continental United States, the raw GCM ensemble median has a historical positive precipitation bias (+24%) and negative PET bias (-7%) compared to the bias-corrected output. While both GCM ensembles (raw and bias-corrected) result in drier conditions in the future, the bias-corrected GCMs produce enhanced aridity (number of months with PET>P) in the late 21st century (2070-2099) compared to the historical climate (1950-1979). For the western United States, the bias-corrected GCM ensemble estimates much less humid and sub-humid conditions (based on P/PET categorical values) than the raw GCM ensemble. However, using June, July, and August PDSI, the bias-corrected GCM ensemble projects less acute decreases for the southwest United States compared to the raw GCM ensemble (1 to 2 PDSI units higher) as a result of larger decreases in projected precipitation in the raw GCM ensemble. A number of examples and ecological implications of this work for the western United States will be presented.

  17. Snails, stable iostopes, and southwestern desert paleoclimates

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.E. [Univ. and Community College System of Nevada, Reno, NV (United States); Whelan, J.F.; Forester, R.M.; Burdett, J.

    1995-09-01

    Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearing air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.

  18. Seven Global Goals. 2013 annual report, Southwestern Power Administration

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-09-01

    For over 70 years, Southwestern has marketed and delivered reliable, renewable, and affordable hydropower, partnering with Federal power stakeholders and others in the industry to make sure the lights stay on. This kind of effective, efficient, and cost conscious operation is made possible only by hard work and dedication. Southwestern employees work individually and as a team to meet seven comprehensive agency goals that touch on all aspects of the agency’s operations. Dubbed the “Seven Global Goals” by Administrator Chris Turner, these objectives identify specific, measurable targets that support Southwestern’s mission and reinforce its responsibilities toward its customers and the Nation.

  19. Late glacial aridity in southern Rocky Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Davis, O.K.; Pitblado, B.L. [Univ. of Arizona, Tucson, AZ (United States)

    1995-09-01

    While the slopes of the present-day Colorado Rocky Mountains are characterized by large stands of subalpine and montane conifers, the Rockies of the late glacial looked dramatically different. Specifically, pollen records suggest that during the late glacial, Artemisia and Gramineae predominated throughout the mountains of Colorado. At some point between 11,000 and 10,000 B.P., however, both Artemisia and grasses underwent a dramatic decline, which can be identified in virtually every pollen diagram produced for Colorado mountain sites, including Como Lake (Sangre de Cristo Mountains), Copley Lake and Splains; Gulch (near Crested Butte), Molas Lake (San Juan Mountains), and Redrock Lake (Boulder County). Moreover, the same pattern seems to hold for pollen spectra derived for areas adjacent to Colorado, including at sites in the Chuska Mountains of New Mexico and in eastern Wyoming. The implications of this consistent finding are compelling. The closest modem analogues to the Artemisia- and Gramineae-dominated late-glacial Colorado Rockies are found in the relatively arid northern Great Basin, which suggests that annual precipitation was much lower in the late-glacial southern Rocky Mountains than it was throughout the Holocene.

  20. Salinization mechanisms in semi-arid regions

    International Nuclear Information System (INIS)

    During a period of three years the basins of the Pereira de Miranda and Caxitore dams, located in the crystalline rock area of Ceara, Brazil, were studied in order to determine the mechanisms of salinization of their waters. Isotope methods (18O/16O) and hidrochemistry (determination of the of the maior ions) were applied to surface, underground and rain water in this study. An isotope model was designed and applied to the determination of evaporation and percolation of dams in semi-arid zones during the dry season. The results are compared to those from a conventional chemical model. As causes of salinization of the water in the dams, the contributions of the rain itself and the lixiviation of the soil are quantified. An interaction between the dams and the underground water is imperceptible. The salinization of the underground water is attributed to recharge of the aquifer with rain water from the surface runoff followed by evaporation of the water rising, due to capilarity, in a one-directional flow to the surface. (Author)

  1. The energy behind the power. Southwestern Power Administration 1994 annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This is the Southwestern Power Administration 1994 annual report. The topics of the report include a letter to the secretary; an overview including the mission statement, a description of the Southwestern Federal Power System, financial statement, performance measurements, national performance review; year in review, summary of results, financial and statistical data and the Southwestern Power Administration Organization.

  2. Entomological studies for surveillance and prevention of dengue in arid and semi-arid districts of Rajasthan, India

    Directory of Open Access Journals (Sweden)

    Anil Purohit

    2008-05-01

    Full Text Available Background & objectives: Rajasthan is one of the dengue endemic states of India. Very few studies have been published on entomological aspects of dengue in this state. Owing to water scarcity, inhabitants in desert areas overstore domestic water which leads to the persistence of dengue vectors within the domestic premises. Area specific knowledge on breeding, key containers and seasonal rhythms of vector population is essential for preparing an effective prevention plan against dengue. Present paper reports results of entomological investigations on dengue vectors in arid and semi-arid districts of Rajasthan. Methods: Longitudinal studies were undertaken during 2004–06 in one arid and two semi-arid dengue endemic districts of Rajasthan. Adult and larval Aedes were collected from the randomly selected houses in representative towns and villages with associated details of container types and water storage practices of inhabitants. Results: In urban areas during all the seasons adult house index (AHI of Aedes aegypti was maximum in desert zone (25 and least in semi-arid area with saline river III (1. The difference of AHI during three seasons was statistically significant (c2 = 16.1, p <0.01 for urban; and c2 = 50.71, p < 0.001 for rural. Breeding of Ae. aegypti among urban settings was maximum in desert zone. During all the seasons cement tanks were the key breeding habitats for Ae. aegypti in desert as well as semi-arid areas. Interpretation & conclusion: Water storage habits during summer season emerged to be the risk factor of vector abundance in urban areas of arid and semi-arid settings. A carefully designed study of key containers targeting cement tanks as the primary habitats of mosquito control may lead to commendable results for dengue prevention.

  3. Recent changes in continentality and aridity conditions over the Middle East and North Africa region, and their association with circulation patterns

    KAUST Repository

    El Kenawy, Ahmed M.

    2016-05-30

    A long-term (1960-2013) assessment of the variability of continentality and aridity conditions over the Middle East and North Africa (MENA) region was undertaken. Monthly gridded temperature and precipitation data from the Climate Research Unit (CRU) (TS3.22 version) were used to compute the Johansson Continentality Index (JCI) and the Marsz Oceanity Index (MOI). In addition, the De Martonne index and the Pinna index were employed to assess recent changes in aridity conditions. All indices revealed a statistically significant increase in continental influences over the region, particularly in the Nile Basin and the Fertile Crescent. For aridity, the results suggested a generally statistically insignificant increase, with the most rapid changes occurring over the most humid regions (i.e. the Ethiopian Highlands and the Fertile Crescent). In order to explain the observed changes in the continentality and aridity conditions, we assessed the relationship between aridity and continentality indices and a wide range of large-scale circulation patterns. Results indicate that the spatial variability of continentality (as well as aridity) was closely coupled with the Atlantic modes of variability, e.g. the Eastern Atlantic pattern and the Atlantic Meridional Mode, compared to those of the Mediterranean Sea and the Indian Ocean. The results of this work highlight change processes in 2 important climate features in one of the hottest regions on Earth. Improving our understanding of the spatio-temporal characteristics of climate continentality and aridity has implications for a diversity of socio-political, economic, hydrological, and ecological activities in the MENA region.

  4. UNESCO's G-WADI Program - Developing and Delivering Tools for Improved Water Management in Semi-arid and Arid Lands

    Science.gov (United States)

    Woodard, G. C.; Imam, B.; Sorooshian, S.

    2007-12-01

    UNESCO's Water and Development Information for Arid Lands - A Global Network (G-WADI) aims to strengthen the capacity to manage the water resources of arid and semi-arid areas around the globe through a network of international and regional cooperation. Six centers, including SAHRA headquartered at the University of Arizona and CHRS at UC-Irvine, are cooperating to improve water resource management by sharing knowledge and tools. Specific objectives include: improved understanding of the special characteristics of hydrological systems and water management needs in arid areas, through shared data and experiences; capacity building of individuals and institutions; raising awareness of advanced technologies for data provision, data assimilation, and system analysis; and promoting integrated basin management and the use of appropriate decision support tools. SAHRA coordinates G-WADI's information dissemination via G-WADI's web site and publications. Web-based resources include Global Water News Watch and the subscription service, Water News Tracker, plus access to remotely sensed precipitation data from HyDIS. Information on use of isotopes and chemical tracers is also featured. Materials and outcomes from various workshops and short courses on modeling, water harvesting, and impacts of climate change also are provided. While the intent is to benefit water resource managers in semi- arid and arid developing countries, the collaboration among international water centers, and perspectives and traditional knowledge gained from users, has benefitted U.S. researchers in many ways.

  5. Landscape eco-environment risk assessment of highway in arid area of Xinjiang,China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the aid of analyses to landscape ecology in the highway region of the arid area in Xinjiang of China, vegetation type, soil type and land-use type were ascertained as environmental factors of highway landscape ecosystem fragility, and seasonal flood, blown-wind sand and alkali-salinization as disaster factors of highway engineering. All items of these factors constitute an objective hierarchy of evaluating landscape ecosystem risk of the highway region in the arid area. The weighted values of the items were determined according to the number of occupied area or length by them against each unit. The area or length was interpreted with the aids of GIS technology and gained by measuring in the highway reconnaissance. The results of the eco-environmental risk assessment of G315 Yitunbulake-Qiemo section in Xinjiang shows that eight units of landscape ecology can be sorted into four categories according to the differences of the fragility indices (Σxiwi) and the disaster indices (Σyiwj).

  6. Aquaculture and mangrove ecosys of temproductivity in arid and semi-arid Balochistan coastal environments

    International Nuclear Information System (INIS)

    A survey of coastal shrimp-pond operations, and the structure and functioning of coastal mangrove forest ecosystems with particular reference to Ecuador, indicates that certain physical parameters may be good predictors of key biological processes. The most important factors are those associated with the regional water balance, tidal and surface water circulation patterns, and the physicochemical properties of the underlying soils. One important conclusion to emerge from the analyses is that at both regional and local levels, well-developed and productive mangrove forest areas often represent the least desirable sites for the construction and operation of commercial shrimp ponds. In certain regards semi-arid and arid coastal environments where mangroves are poorly developed, shrimp ponds that are constructed on barren mud flats and inland salt pans appear to have the potential to produce higher yields of shrimp with fewer management problems and at a relatively lower production cost. The data and research results from coast of Baluchistan and elsewhere are briefly summarized to suggest why productive mangrove ecosystems to not make the best areas in which to obtain maximum shrimp-pond yields. (author)

  7. Predictability and prediction of summer rainfall in the arid and semi-arid regions of China

    Science.gov (United States)

    Xing, Wen; Wang, Bin

    2016-09-01

    Northwest China (NWC) is an arid and semi-arid region where climate variability and environmental changes are sensitive to precipitation. The present study explores sources and limits of predictability of summer precipitation over NWC using the predictable mode analysis (PMA) of percentage of rainfall anomaly data. Two major modes of NWC summer rainfall variability are identified which are tied to Eurasian continental scale precipitation variations. The first mode features wet northern China corresponding to dry central Siberia and wet Mongolia, which is mainly driven by tropical Pacific sea surface temperature anomalies (SSTA). The second mode features wet western China reflecting wet Central Asia and dry Ural-western Siberia, which strongly links to Indian Ocean SSTA. Anomalous land warming over Eurasia also provides important precursors for the two modes. The cross-validated hindcast results demonstrate these modes can be predicted with significant correlation skills, suggesting that they may be considered as predictable modes. The domain averaged temporal correlation coefficient (TCC) skill during 1979 to 2015 using 0-month (1-month) lead models is 0.39 (0.35), which is considerably higher than dynamical models' multi-model ensemble mean skill (-0.02). Maximum potential attainable prediction skills are also estimated and discussed. The result illustrates advantage of PMA in predicting rainfall over dry land areas and large room for dynamical model improvement. However, secular changes of predictors need to be detected continuously in order to make practical useful prediction.

  8. Adaptation to drought in arid and semi-arid environments: Case of the Zambezi Valley, Zimbabwe

    Directory of Open Access Journals (Sweden)

    Emmanuel Mavhura

    2015-02-01

    Full Text Available Small-scale rain-fed agriculture is the main livelihood in arid to semi-arid regions of subSaharan Africa. The area is characterised by erratic rainfall and frequent droughts, making the capacity for coping with temporal water shortages essential for smallholder farmers. Focusing on the Zambezi Valley, Zimbabwe, this study investigates the impact of drought on food security and the strategies used by smallholder farmers to cope with drought. We used meteorological data and interviews to examine the rainfall variability in the study area and the drought-coping mechanisms employed by smallholder famers respectively. The results show that there are various strategies used by smallholder farmers to cope with the impact of drought. These strategies include drought-tolerant crop production, crop variety diversification, purchasing cereals through asset sales, non-governmental organisations’ food aid and gathering wild fruit. However, consecutive droughts have resulted in high food insecurity and depletion of household assets during droughts. Smallholder farmers in the valley have also resorted to a number of measures taken before, during and after the drought. Still, these strategies are not robust enough to cope with this uncertainty

  9. Characterization of the aeolian terrain facies in Wadi Araba Desert, southwestern Jordan

    Science.gov (United States)

    Saqqa, Walid; Atallah, Mohammad

    2004-09-01

    The sand dunes in Wadi Araba Desert, southwestern Jordan, conform to the influence of two main wind systems: (1) the Shamal " north wind", the main determinant of dune patterns, and (2) the southerly winds caused by the Red Sea Trough and Khamasin winds. Wadi Araba is a narrow elongated morphotectonic depression bordered by the high eastern and western mountain ranges that would obstruct most of westerlies in winter and the hot dry easterlies in summer. Wadi Araba Desert is caused by the rain shadow of the eastern and western topographic highs, with an arid-hyperarid climate and moisture index between 0.1 and Araba Desert divided into four sand dune fields that contain different dune types, interdunes, and sand sheet facies. The development of the aeolian terrain was more likely in the interglacial periods of latest Pleistocene-Holocene during which wind deposition and fluvial erosion were prompted. The variability of wind direction, wind speed and rates of sand supply led to a variety of simple, compound and complex dune formations. Barchanoid (barchan, barchanoid ridge, transverse dunes) are very common. Linear dunes, nabkhas and climbing dunes are less common. The dunes in Wadi Araba are either mobile (active) or stabilized. Dune fixation is primarily by desert shrubs or cementation in case of aeolianites. Interdune troughs vary from dry to damp. Sand sheets are mainly unvegetated or barren. Dune sands are well sorted to moderately well sorted with more than half the sand falling in fine-medium sand fraction. Interdune areas and sheet sands are moderately-poorly sorted with grain size between 0.06-5 and 0.1-0.5 mm, respectively. Angular-subrounded grain shapes are relatively common on all sides of barchanoid dunes. The sediments of the aeolian terrain are chiefly composed of quartz, feldspar, mica and kaolinite. Calcite and dolomite are less predominant minerals.

  10. Hydrologic effects of large southwestern USA wildfires significantly increase regional water supply: fact or fiction?

    Science.gov (United States)

    Wine, M. L.; Cadol, D.

    2016-08-01

    In recent years climate change and historic fire suppression have increased the frequency of large wildfires in the southwestern USA, motivating study of the hydrological consequences of these wildfires at point and watershed scales, typically over short periods of time. These studies have revealed that reduced soil infiltration capacity and reduced transpiration due to tree canopy combustion increase streamflow at the watershed scale. However, the degree to which these local increases in runoff propagate to larger scales—relevant to urban and agricultural water supply—remains largely unknown, particularly in semi-arid mountainous watersheds co-dominated by winter snowmelt and the North American monsoon. To address this question, we selected three New Mexico watersheds—the Jemez (1223 km2), Mogollon (191 km2), and Gila (4807 km2)—that together have been affected by over 100 wildfires since 1982. We then applied climate-driven linear models to test for effects of fire on streamflow metrics after controlling for climatic variability. Here we show that, after controlling for climatic and snowpack variability, significantly more streamflow discharged from the Gila watershed for three to five years following wildfires, consistent with increased regional water yield due to enhanced infiltration-excess overland flow and groundwater recharge at the large watershed scale. In contrast, we observed no such increase in discharge from the Jemez watershed following wildfires. Fire regimes represent a key difference between the contrasting responses of the Jemez and Gila watersheds with the latter experiencing more frequent wildfires, many caused by lightning strikes. While hydrologic dynamics at the scale of large watersheds were previously thought to be climatically dominated, these results suggest that if one fifth or more of a large watershed has been burned in the previous three to five years, significant increases in water yield can be expected.

  11. Characterization of magnetically enhanced buried soil layer in arid environment

    Science.gov (United States)

    Petrovsky, E.; Grison, H.; Kapicka, A.; Silva, P. F.; Font, E.

    2011-12-01

    Magnetic susceptibility (MS) of soils, reflecting the presence of magnetite/maghemite, can be used in several environmental applications. Magnetic topsoil mapping is often used to outline areas polluted by atmospherically deposited dust. However, in these studies, the magnetically enhanced layer is usually shallow, some 5-6 cm under the surface. In our contribution, we present the case when the magnetic susceptibility is enhanced in deeper soil layers. Investigated soils are mostly sandy soils, from several localities in Portugal, in a zone with arid climate. Sample profiles were collected always in forests or forest stands with pines, cork oaks or eucalyptus trees in two areas: around the city of Sines (on the coast south of Lisbon) and around the city of Abrantes (inland, north-east of Lisbon). Both areas are presumably affected by one major source of pollution - power plant. Surface magnetic susceptibility measurements were performed by Bartington MS2D loop; values vary from 10 to 300 x 10-5 SI units. Vertical distribution of magnetic susceptibility was measured already in situ using the SM400 (ZHInstruments) on profiles about 40cm in length. Mass-specific MS was determined using Bartington MS2B dual frequency meter and Agico MFK1. Nine vertical profiles were selected for detailed analyses including the ARM, IRM and hysteresis measurements. Distinctly enhanced magnetic layers were detected in deeper horizons. This enhancement can be ascribed to several mechanisms. Migration of magnetic particles seems to be probable, as observed in our model experiments with sand columns. In coastal areas, the enhanced layer could be due to tsunami deposits, as described in other areas. Finally, in particular at sites close to power plants, the construction works followed by surface remediation have to be also considered as one of the possible mechanisms.

  12. Shallow Horizontal GCHP Effectiveness in Arid Climate Soils

    Science.gov (United States)

    North, Timothy James

    Ground coupled heat pumps (GCHPs) have been used successfully in many environments to improve the heating and cooling efficiency of both small and large scale buildings. In arid climate regions, such as the Phoenix, Arizona metropolitan area, where the air condi-tioning load is dominated by cooling in the summer, GCHPs are difficult to install and operate. This is because the nature of soils in arid climate regions, in that they are both dry and hot, renders them particularly ineffective at dissipating heat. The first part of this thesis addresses applying the SVHeat finite element modeling soft-ware to create a model of a GCHP system. Using real-world data from a prototype solar-water heating system coupled with a ground-source heat exchanger installed in Menlo Park, California, a relatively accurate model was created to represent a novel GCHP panel system installed in a shallow vertical trench. A sensitivity analysis was performed to evaluate the accuracy of the calibrated model. The second part of the thesis involved adapting the calibrated model to represent an ap-proximation of soil conditions in arid climate regions, using a range of thermal properties for dry soils. The effectiveness of the GCHP in the arid climate region model was then evaluated by comparing the thermal flux from the panel into the subsurface profile to that of the prototype GCHP. It was shown that soils in arid climate regions are particularly inefficient at heat dissipation, but that it is highly dependent on the thermal conductivity inputted into the model. This demonstrates the importance of proper site characterization in arid climate regions. Finally, several soil improvement methods were researched to evaluate their potential for use in improving the effectiveness of shallow horizontal GCHP systems in arid climate regions.

  13. Holocene insect remains from south-western Greenland

    DEFF Research Database (Denmark)

    Bøcher, Jens Jensenius; Bennike, Ole; Wagner, Bernd

    2012-01-01

    Remains of plants and invertebrates from Holocene deposits in south-western Greenland include a number of insect fragments from Heteroptera and Coleoptera. Some of the finds extend the known temporal range of the species considerably back in time, and one of the taxa has not previously been found...... remains of terrestrial insects complement the scarce fossil Greenland record of the species concerned....

  14. Monochroa bronzella sp. n. from the southwestern Alps (Lepidoptera: Gelechiidae)

    DEFF Research Database (Denmark)

    Karsholt, Ole; Nel, Jacques; Fournier, François;

    2013-01-01

    Abstract. Monochroa bronzella sp. n. is described from the southwestern Alps (France, Italy). It is closely related to M. nomadella (Zeller, 1868), with which it was hitherto confused. Literature records of M. nomadella from France and northwestern Italy refer to M. bronzella sp. n. The two speci...

  15. Genetic diversity of Ascaris in southwestern Uganda

    DEFF Research Database (Denmark)

    Betson, Martha; Nejsum, Peter; Llewellyn-Hughes, Julia;

    2012-01-01

    Despite the common occurrence of ascariasis in southwestern Uganda, helminth control in the region has been limited. To gain further insights into the genetic diversity of Ascaris in this area, a parasitological survey in mothers (n=41) and children (n=74) living in two villages, Habutobere and M...

  16. 2014 annual site environmental report, Southwestern Power Administration

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-12-31

    Southwestern Power Administration’s Annual Site Environmental Report (ASER) serves as the chief reporting mechanism for site environmental performance information within the Department of Energy and as a valuable resource for shared and collaborative environmental protection and performance information to Agency stakeholders and members of the public living near Southwestern Power Administration’s (Southwestern) facilities and transmission line rights-of-ways. This ASER meets the requirements of Department of Energy (DOE) Order 231.B. Southwestern’s key environmental involvement includes an emphasis on the protection of ecological resources which is effectively accomplished through environmental program elements such as protecting water resources, generation of clean hydropower energy, oil spill prevention practices, elimination of green-house gas emissions, and comprehensive project reviews to ensure the protection of living organisms, migratory birds, Federally threatened or endangered species, and historic or cultural resources. Southwestern continues to actively minimize effects to natural resources and strive for continual improvement in the area of environmental compliance and sustainability while achieving the agency mission to market and deliver Federal hydroelectric power.

  17. Holocene palaeoclimate and sea level fluctuation recorded from the coastal Barker Swamp, Rottnest Island, south-western Western Australia

    Science.gov (United States)

    Gouramanis, C.; Dodson, J.; Wilkins, D.; De Deckker, P.; Chase, B. M.

    2012-10-01

    The Holocene palaeoclimatic history of south-western Western Australia (SWWA) has received little attention compared to south-eastern Australia, and this has resulted in conflicting views over the impact of climate variability in the region. We present here a well-dated, high-resolution record from two overlapping sediment cores obtained from the centre of Barker Swamp, Rottnest Island, offshore Perth. The records span the last 8.7 ka, with the main lacustrine phase occurring after 7.4 ka. This site preserves both pollen and several ostracod taxa. The pollen record suggests a long-term shift from the early-mid Holocene to the late Holocene to drier conditions with less shrubland and more low-ground cover and less fire activity. A salinity transfer function was developed from ostracod faunal assemblage data and trace metal ratios (Mg/Ca, Sr/Ca and Na/Ca) and stable isotopes (δ18O and δ13C) analysed on selected ostracod valves. These provide a detailed history of evaporation/precipitation (E/P) differences that clearly shows that the SWWA region was subjected to significant climatic shifts over the last 7.4 ka, with a broad shift towards increased aridity after 5 ka. The swamp ranged from fresh to saline as recorded in the ostracod valve chemistry and the independently-derived salinity transfer function. The ostracod record also indicates that a sea-level highstand occurred between ca. 4.5 and 4.3 ka, with probable step-wise increases at 6.75, 6.2, and 5.6 ka, with the last vestiges of salt water intrusion at ca. 1 ka. After about 2.3 ka, the fresh, groundwater lens that underlies the western portion of the island intersected the swamp depression, influencing the hydrology of the swamp. The broad climatic changes recorded in Barker Swamp are also compared with data from southern South Africa, and it is suggested that the Southern Annular Mode appears to have been the dominant driver in the climate of these regions and that the Indian Ocean Dipole is of little

  18. Southwestern Power Administration Annual Report 2004-2006

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-01-01

    Confidence Commitment Cooperation These are words that spring to mind regarding Southwestern Power Administration’s performance during fiscal years (FY) 2004-2006 By offering innovative, customer-oriented service, working to improve system reliability and efficiency, and partnering with customers and other Federal power stakeholders, Southwestern has certainly exhibited all three of these qualities during these challenging yet productive years In fact, our cooperative working relationships were critical to our success during the severe and widespread drought conditions which prevailed throughout Southwestern’s marketing area for much of 2005-2006 When we proposed a temporary energy deferral program, our customers came on board by voluntarily taking less Federal hydropower than they were entitled to, enabling us to preserve system storage and fulfill our contract obligations during the crucial summer months of 2006 The U S Army Corps of Engineers (Corps) also helped improve our drought situation by allowing Southwestern more operational flexibility on a regional level Despite the challenges this critical drought period presented, Southwestern remained committed to fulfilling our mission and strategic goals From FY 2004 through FY 2006, we marketed and delivered all available Federal hydropower while meeting and even exceeding the reliability standards of the North American Electric Reliability Corporation (NERC) Our Power Operations Training Center in Springfield, Missouri, was cited as an “Example of Excellence” during a NERC readiness audit in October 2006; and as we have every year since NERC began measuring, Southwestern far exceeded the accepted NERC compliance ratings for power system operations reliability Our commitment to excellence and accountability has kept our repayment goals on target as well Revenues were sufficient to repay all annual expenses and the required principal investment in the Federal hydropower facilities Furthermore, the original

  19. Spatial data fusion and analysis for soil characterization: a case study in a coastal basin of south-western Sicily (southern Italy

    Directory of Open Access Journals (Sweden)

    Donato Sollitto

    2012-03-01

    Full Text Available Salinization is one of the most serious problems confronting sustainable agriculture in semi-arid and arid regions. Accurate mapping of soil salinization and the associated risk represent a fundamental step in planning agricultural and remediation activities. Geostatistical analysis is very useful for soil quality assessment because it makes it possible to determine the spatial relationships between selected variables and to produce synthetic maps of spatial variation. The main objective of this paper was to map the soil salinization risk in the Delia-Nivolelli alluvial basin (south-western Sicily, southern Italy, using multivariate geostatistical techniques and a set of topographical, physical and soil hydraulic properties. Elevation data were collected from existing topographic maps and analysed preliminarily to improve the estimate precision of sparsely sampled primary variables. For interpolation multi-collocated cokriging was applied to the dataset, including textural and hydraulic properties and electrical conductivity measurements carried out on 128 collected soil samples, using elevation data as auxiliary variable. Spatial dependence among elevation and physical soil properties was explored with factorial kriging analysis (FKA that could isolate and display the sources of variation acting at different spatial scales. FKA isolated significant regionalised factors which give a concise description of the complex soil physical variability at the different selected spatial scales. These factors mapped, allowed the delineation of zones at different salinisation risk to be managed separately to control and prevent salinization risk. The proposed methodology could be a valid support for land use and soil remediation planning at regional scale.

  20. Empirical assessment of debris flow risk on a regional scale in Yunnan province, southwestern China.

    Science.gov (United States)

    Liu, Xilin; Yue, Zhong Qi; Tham, Lesliw George; Lee, Chack Fan

    2002-08-01

    Adopting the definition suggested by the United Nations, a risk model for regional debris flow assessment is presented. Risk is defined as the product of hazard and vulnerability, both of which are necessary for evaluation. A Multiple-Factor Composite Assessment Model is developed for quantifying regional debris flow hazard by taking into account eight variables that contribute to debris flow magnitude and its frequency of occurrence. Vulnerability is a measure of the potential total losses. On a regional scale, it can be measured by the fixed asset, gross domestic product, land resources, population density, as well as the age, education, and wealth of the inhabitants. A nonlinear power-function assessment model that accounts for these indexes is developed. As a case study, the model is applied to compute the hazard, vulnerability and risk for each prefecture of the Yunnan province in southwestern China. PMID:12105765

  1. Phytostabilization of Mine Tailings in Arid and Semiarid Environments—An Emerging Remediation Technology

    Science.gov (United States)

    Mendez, Monica O.; Maier, Raina M.

    2008-01-01

    Objective Unreclaimed mine tailings sites are a worldwide problem, with thousands of unvegetated, exposed tailings piles presenting a source of contamination for nearby communities. Tailings disposal sites in arid and semiarid environments are especially subject to eolian dispersion and water erosion. Phytostabilization, the use of plants for in situ stabilization of tailings and metal contaminants, is a feasible alternative to costly remediation practices. In this review we emphasize considerations for phytostabilization of mine tailings in arid and semiarid environments, as well as issues impeding its long-term success. Data sources We reviewed literature addressing mine closures and revegetation of mine tailings, along with publications evaluating plant ecology, microbial ecology, and soil properties of mine tailings. Data extraction Data were extracted from peer-reviewed articles and books identified in Web of Science and Agricola databases, and publications available through the U.S. Department of Agriculture, U.S. Environmental Protection Agency, and the United Nations Environment Programme. Data synthesis Harsh climatic conditions in arid and semiarid environments along with the innate properties of mine tailings require specific considerations. Plants suitable for phytostabilization must be native, be drought-, salt-, and metal-tolerant, and should limit shoot metal accumulation. Factors for evaluating metal accumulation and toxicity issues are presented. Also reviewed are aspects of implementing phytostabilization, including plant growth stage, amendments, irrigation, and evaluation. Conclusions Phytostabilization of mine tailings is a promising remedial technology but requires further research to identify factors affecting its long-term success by expanding knowledge of suitable plant species and mine tailings chemistry in ongoing field trials. PMID:18335091

  2. Actinobacteria from arid and desert habitats: diversity and biological activity

    Directory of Open Access Journals (Sweden)

    Joachim eWink

    2016-01-01

    Full Text Available Abstract The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and ecosystems. Bioprospecting of extremophilic Actinobacteria through mining untapped strains and avoiding resiolation of known biomolecules is among the most promising strategies for this purpose. With this approach, members of acidtolerant, alkalitolerant, psychrotolerant, thermotolerant, halotolerant and xerotolerant Actinobacteria have been obtained from respective habitats. Among these, little survey exists on the diversity of Actinobacteria in arid areas, which are often adapted to relatively high temperatures, salt concentrations, and radiation. Therefore, arid and desert habitats are special ecosystems which can be recruited for the isolation of uncommon Actinobacteria with new metabolic capability.At the time of this writing, members of Streptomyces, Micromonospora, Saccharothrix, Streptosporangium, Cellulomonas, Amycolatopsis, Geodermatophilus, Lechevalieria, Nocardia and Actinomadura are reported from arid habitats. However, metagenomic data present dominant members of the communities in desiccating condition of areas with limited water availability that are not yet isolated. Furthermore, significant diverse types of polyketide synthase (PKS and nonribosomal peptide synthetase (NRPS genes are detected in xerophilic and xerotolerant Actinobacteria and some bioactive compounds are reported from them. Rather than pharmaceutically active metabolites, molecules with protection activity against drying such as Ectoin and Hydroxyectoin with potential application in industry and agriculture have also been identified from xerophilic Actinobacteria. In addition, numerous biologically active small molecules are expected to be discovered from arid adapted Actinobacteria in the future. In the current survey, the diversity and biotechnological potential of Actinobacteria

  3. Jojoba - a promising plant for the semi-arid regions. [North America, plants, seeds, oils, waxes, growth, cultivation, lubricants, guayule, mesquite

    Energy Technology Data Exchange (ETDEWEB)

    Yermanos, D.M.

    1979-01-01

    As a result of the world-wide concern for conservation of resources and for the development of new renewable resources a great deal of attention has been directed towards the development of jojoba as a potential new crop for semi-arid regions. Jojoba grows wild in the Southwestern U.S. and N. Mexico, in areas where the annual precipitation is 4''-15''. Under cultivation it appears to grow satisfactorily in areas of marginal soil fertility, high salinity and high atmospheric temperatures. It appears to have no major natural enemies and to be tolerant to chemical treatments, if they were to become necessary. It is perennial with an assumed life span in excess of 150 years. Jojoba seed has an average weight of about 0.5 grams per seed, and it contains a unique liquid wax which is a superior lubricant and a potential replacement of whale oil, obtained from the sperm whale, and endangered species. Thus, jojoba has a double appeal, first as a potential crop of semi-arid regions requiring low cultural and energy inputs and second as a source of a valuable commodity. It should be pointed out that a cheap and abundant source of lubricants will disappear when our stock of fossil fuels are exhausted and that none of our new sources of energy have lubricants as by-products. Finally, jojoba could be grown with other companion crops such as guayule or mesquite for more diversified farming.

  4. Workshop on environmental changes of arid regions convenes in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Hosted by the CAS Institute of Geology and Geophysics and the local government, the International Workshop on Environmental Changes and Sustainable Development in Arid and Semi-arid Regions was held recently in Alashan Left Banner, Inner Mongolia.

  5. Assessment of future agricultural conditions in southwestern Africa using fuzzy logic and high-resolution climate model scenarios

    Directory of Open Access Journals (Sweden)

    Weinzierl, Thomas

    2015-12-01

    Full Text Available Climate change is expected to have a major impact on the arid savanna regions of southwestern Africa, such as the Okavango Basin. Precipitation is a major constraint for agriculture in countries like Namibia and Botswana and assessments of future crop growth conditions are in high demand. This GIS-based approach uses reanalysis data and climate model output for two scenarios and compares them to the precipitation requirements of the five most important crops grown in the region: maize, pearl millet, sorghum, cassava and cow pea. It also takes into account the dominant soil types, as plant growth is also limited by nutrient-poor soils with unfavorable physical and chemical properties. The two factors are then combined using a fuzzy logic algorithm. The assessment visualizes the expected shifts in suitable zones and identifies areas where farming without irrigation may experience a decline in yields or may even no longer be possible at the end of the 21st century. The results show that pearl millet is the most suitable crop in all scenarios while especially the cultivation of maize, sorghum and cow pea may be affected by a possible reduction of precipitation under the high-emission scenario.

  6. New crops for arid lands. [Jojoba; Buffalo gourd; Bladderpod; Gumweed

    Energy Technology Data Exchange (ETDEWEB)

    Hinman, C.W.

    1984-09-28

    Five plants are described that could be grown commercially under arid conditions. Once the most valuable component has been obtained from each plant (rubber from guayule; seed oil from jojoba, buffalo gourd, and bladderpod; and resin from gumweed), the remaining material holds potential for useful products as well as fuel. It is difficult to realize the full potential of arid land plants, however, because of the complexities of developing the necessary agricultural and industrial infrastructure simultaneously. To do so, multicompany efforts or cooperative efforts between government and the private sector will be required.

  7. Potential of arid zone vegetation as a source of substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bassham, J.A.

    1977-11-01

    Three aspects of the potential of vegetation in arid zones as a source of substrates are discussed. The first includes the limitations on efficiency of conversion of solar energy to the stored chemical energy of biomass in green plants, and the subsequent biochemical pathways of carbon dioxide fixation and biosynthesis. Second is the potential of plants endogenous to arid zones. Finally, the use of covered agriculture or controlled environmental agriculture (CEA) is considered both in its present form and in terms of possible extenion to the large scale production of stable crops. (JGB)

  8. a Proposed New Vegetation Index, the Total Ratio Vegetation Index (trvi), for Arid and Semi-Arid Regions

    Science.gov (United States)

    Fadaei, H.; Suzuki, R.; Sakai, T.; Torii, K.

    2012-07-01

    Vegetation indices that provide important key to predict amount vegetation in forest such as percentage vegetation cover, aboveground biomass, and leaf-area index. Arid and semi-arid areas are not exempt of this rule. Arid and semi-arid areas of northeast Iran cover about 3.4 million ha and are populated by two main tree species, the broadleaf Pistacia vera (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environmentally important but also genetically essential as seed sources for pistachio production in orchards. We investigated the relationships between tree density and vegetation indices in the arid and semi-arid regions in the northeast of Iran by analysing Advanced Land Observing Satellite (ALOS) data PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, and has one band with a wavelength of 0.52-0.77 μm (JAXA EORC). AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, and has four multispectral bands: blue (0.42-0.50 μm), green (0.52-0.60 μm), red (0.61-0.69 μm), and near infrared (0.76-0.89 μm) (JAXA EORC). In this study, we estimated various vegetation indices using maximum filtering algorithm (5×5) and examined. This study carried out of juniper forests and natural pistachio stand using Advanced Land Observing Satellite (ALOS) and field inventories. Have been compared linear regression model of vegetation indices and proposed new vegetation index for arid and semi-arid regions. Also, we estimated the densities of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. We present a new vegetation index for arid and semi-arid regions with sparse forest cover, the Total Ratio Vegetation Index (TRVI), and we investigate the relationship of the new index to tree density by analysing data from the

  9. A PROPOSED NEW VEGETATION INDEX, THE TOTAL RATIO VEGETATION INDEX (TRVI, FOR ARID AND SEMI-ARID REGIONS

    Directory of Open Access Journals (Sweden)

    H. Fadaei

    2012-07-01

    Full Text Available Vegetation indices that provide important key to predict amount vegetation in forest such as percentage vegetation cover, aboveground biomass, and leaf-area index. Arid and semi-arid areas are not exempt of this rule. Arid and semi-arid areas of northeast Iran cover about 3.4 million ha and are populated by two main tree species, the broadleaf Pistacia vera (pistachio and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper. Natural stands of pistachio in Iran are not only environmentally important but also genetically essential as seed sources for pistachio production in orchards. We investigated the relationships between tree density and vegetation indices in the arid and semi-arid regions in the northeast of Iran by analysing Advanced Land Observing Satellite (ALOS data PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, and has one band with a wavelength of 0.52–0.77 μm (JAXA EORC. AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, and has four multispectral bands: blue (0.42–0.50 μm, green (0.52–0.60 μm, red (0.61–0.69 μm, and near infrared (0.76–0.89 μm (JAXA EORC. In this study, we estimated various vegetation indices using maximum filtering algorithm (5×5 and examined. This study carried out of juniper forests and natural pistachio stand using Advanced Land Observing Satellite (ALOS and field inventories. Have been compared linear regression model of vegetation indices and proposed new vegetation index for arid and semi-arid regions. Also, we estimated the densities of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. We present a new vegetation index for arid and semi-arid regions with sparse forest cover, the Total Ratio Vegetation Index (TRVI, and we investigate the relationship of the new index to tree density by

  10. Efficiency of a Horizontal Sub-Surface Flow Constructed Wetland Treatment System in an Arid Area

    Directory of Open Access Journals (Sweden)

    Abeer Albalawneh

    2016-02-01

    Full Text Available The main objective of this study was to evaluate the performance and treatment efficiency of the Horizontal Sub-Surface Flow Constructed Wetland treatment system (HSF-CW in an arid climate. Seventeen sub-surface, horizontal-flow HSF-CW units have been operated for approximately three years to improve the quality of partially-treated municipal wastewater. The studied design parameters included two sizes of volcanic tuff media (i.e., fine or coarse, two different bed dimensions (i.e., long and short, and three plantation types (i.e., reed, kenaf, or no vegetation as a control. The effluent Biological Oxygen Demand (BOD5, Chemical Oxygen Demand (COD, Total Suspended Solid (TSS, and phosphorus from all of the treatments were significantly lower as compared to the influent and demonstrated a removal efficiency of 55%, 51%, 67%, and 55%, respectively. There were significant increases in Electrical Conductivity (EC, sulfate, and calcium in the effluent of most HSF-CWs due to evaporative concentration and mineral dissolution from the media. The study suggests that unplanted beds with either fine or coarse media are the most suitable combinations among all of the studied designs based on their treatment efficiency and less water loss in arid conditions.

  11. Preliminary soil-slip susceptibility maps, southwestern California

    Science.gov (United States)

    Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.

    2003-01-01

    This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil slip-debris flows in southwestern California. As such, the maps offer a partial answer to one part of the three parts necessary to predict the soil-slip/debris-flow process. A complete prediction of the process would include assessments of “where”, “when”, and “how big”. These maps empirically show part of the “where” of prediction (i.e., relative susceptibility to sites of initiation of the soil slips) but do not attempt to show the extent of run out of the resultant debris flows. Some information pertinent to “when” the process might begin is developed. “When” is determined mostly by dynamic factors such as rainfall rate and duration, for which local variations are not amenable to long-term prediction. “When” information is not provided on the maps but is described later in this narrative. The prediction of “how big” is addressed indirectly by restricting the maps to a single type of landslide process—soil slip-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil slips were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil slips, were used as the basis for soil slip-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil slip locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-slip debris flows were found to be important and others were not. The most important attribute was the mapped bedrock formation at the site of initiation of the soil slip. However, because the soil slips occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as

  12. Impact and consequences of evapotranspiration changes on water resources availability in the arid Zhangye Basin, China

    NARCIS (Netherlands)

    Jin, X.; Schaepman, M.E.; Clevers, J.G.P.W.; Su, Z.

    2009-01-01

    Evapotranspiration (ET) plays an important role in the hydrological cycle and it is essential to estimate ET accurately for the evaluation of available water resources. This is most important in arid and semi-arid regions. In this paper, the long-term changes in daily ET in the semi-arid Zhangye Bas

  13. Utilisation Of Micro-Finance Institutions’ Funds By Borrowers In Arid And Semi-Arid Lands In Kenya

    OpenAIRE

    Nzioki, Paul M.; Taragon, Geoffrey; Kalio, A. M.

    2013-01-01

    Despite a lot of efforts in terms of resource mobilisation in Arid and Semi-Arid Lands (ASAL) , the poverty levels are still very high and the defaulted loans from the four Micro-Finance Institutions (MFIs) in Maralal town amounts KES 15 million. The study sought to establish whether economic characteristics of entrepreneurs and whether literacy levels affect application and usage of borrowed funds in the ASAL regions of Africa. The study was limited to Maralal Town, one of the main towns in ...

  14. Ensemble projections of wildfire activity and carbonaceous aerosol concentrations over the western United States in the mid-21st century

    Science.gov (United States)

    Yue, Xu; Mickley, Loretta J.; Logan, Jennifer A.; Kaplan, Jed O.

    2013-10-01

    We estimate future wildfire activity over the western United States during the mid-21st century (2046-2065), based on results from 15 climate models following the A1B scenario. We develop fire prediction models by regressing meteorological variables from the current and previous years together with fire indexes onto observed regional area burned. The regressions explain 0.25-0.60 of the variance in observed annual area burned during 1980-2004, depending on the ecoregion. We also parameterize daily area burned with temperature, precipitation, and relative humidity. This approach explains ˜0.5 of the variance in observed area burned over forest ecoregions but shows no predictive capability in the semi-arid regions of Nevada and California. By applying the meteorological fields from 15 climate models to our fire prediction models, we quantify the robustness of our wildfire projections at midcentury. We calculate increases of 24-124% in area burned using regressions and 63-169% with the parameterization. Our projections are most robust in the southwestern desert, where all GCMs predict significant (p ecoregions, more GCMs predict significant increases in future area burned with the parameterization than with the regressions, because the latter approach is sensitive to hydrological variables that show large inter-model variability in the climate projections. The parameterization predicts that the fire season lengthens by 23 days in the warmer and drier climate at midcentury. Using a chemical transport model, we find that wildfire emissions will increase summertime surface organic carbon aerosol over the western United States by 46-70% and black carbon by 20-27% at midcentury, relative to the present day. The pollution is most enhanced during extreme episodes: above the 84th percentile of concentrations, OC increases by ˜90% and BC by ˜50%, while visibility decreases from 130 km to 100 km in 32 Federal Class 1 areas in Rocky Mountains Forest.

  15. Watershed Boundaries - WATERSHEDS_HUC11__USGS_IN: Watersheds, 11-digit Hydrologic Units, in Indiana, (Derived from US Geological Survey, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — WATERSHEDS_HUC11_USGS_IN is a polygon shapefile showing the boundaries of watersheds in Southwestern Indiana. Watersheds are noted by a 11-digit hydrologic unit....

  16. Evidence for fullerene in a coal of Yunnan, Southwestern China

    International Nuclear Information System (INIS)

    In two types of coal from a coal mine in Yunnan Province, Southwestern China, the presence of fullerene is confirmed. The fullerene had been suggested earlier by its characteristic infrared absorption spectrum. The present work reports verification by a high performance liquid chromatograph. A critical step leading to the confirmation is in the process of preparation of the liquid solution from the coal for chromatography and this is described. Possible conditions for the search of natural fullerenes are suggested. (orig.)

  17. Ecological restoration of southwestern ponderosa pine ecosystems: A broad perspective

    OpenAIRE

    Allen, C. D.; Savage, M.; Falk, D. A.; Suckling, K. F.; Swetnam, T.W.; Schulke, T.; Stacey, P. B.; Morgan, P.; Hoffman, M; Klingel, J. T.

    2002-01-01

    The purpose of this paper is to promote a broad and flexible perspective on ecological restoration of Southwestern (U.S.) ponderosa pine forests. Ponderosa pine forests in the region have been radically altered by Euro-American land uses, including livestock grazing, fire suppression, and logging. Dense thickets of young trees now abound, old-growth and biodiversity have declined, and human and ecological communities are increasingly vulnerable to destructive crown fires. A consensus has emer...

  18. Correct nomenclature for the Angadimogar pluton, Kerala, southwestern India

    Indian Academy of Sciences (India)

    H M Rajesh

    2006-04-01

    The proper usage of modal composition and geochemical classification of granitoids is discussed for assigning a proper nomenclature for the Angadimogar pluton,Kerala,southwestern India.This discussion is mainly aimed at addressing questions concerning the nomenclature of Angadimogar pluton (syenite vs. granite).Modal composition and whole-rock XRD data clearly show that the pluton exposed near Angadimogar is a quartz-syenite and its geochemistry is typical of a ferroan, metaluminous,alkali (A-type)granitoid.

  19. Descriptive Analyses of Two Late Prehistoric Burials From Southwestern Idaho

    OpenAIRE

    Yohe, Robert M II; St. Clair, Jessica

    1998-01-01

    Data relating to prehistoric human skeletal material from the northern cultural Great Basin are scant, especially for the period dating within the last 2,000 years. Recent discoveries of two separate prehistoric inhumations in southwestern Idaho resulted in professional data recovery efforts by the Idaho State Historical Society. The radiometric assessments of the remains place the date of the interments at approximately 900 and 1,300 years ago. Descriptions of each burial and associated arti...

  20. Growing season soil moisture following restoration treatments of varying intensity in semi-arid ponderosa pine forests

    Science.gov (United States)

    O'Donnell, F. C.; Springer, A. E.; Sankey, T.; Masek Lopez, S.

    2014-12-01

    Forest restoration projects are being planned for large areas of overgrown semi-arid ponderosa pine forests of the Southwestern US. Restoration involves the thinning of smaller trees and prescribed or managed fire to reduce tree density, restore a more natural fire regime, and decrease the risk of catastrophic wildfire. The stated goals of these projects generally reduced plant water stress and improvements in hydrologic function. However, little is known about how to design restoration treatments to best meet these goals. As part of a larger project on snow cover, soil moisture, and groundwater recharge, we measured soil moisture, an indicator of plant water status, in four pairs of control and restored sites near Flagstaff, Arizona. The restoration strategies used at the sites range in both amount of open space created and degree of clustering of the remaining trees. We measured soil moisture using 30 cm vertical time domain reflectometry probes installed on 100 m transects at 5 m intervals so it would be possible to analyze the spatial pattern of soil moisture. Soil moisture was higher and more spatially variable in the restored sites than the control sites with differences in spatial pattern among the restoration types. Soil moisture monitoring will continue until the first snow fall, at which point measurements of snow depth and snow water equivalent will be made at the same locations.

  1. Digital Atlas of the Upper Washita River Basin, Southwestern Oklahoma

    Science.gov (United States)

    Becker, Carol J.; Masoner, Jason R.; Scott, Jonathon C.

    2008-01-01

    Numerous types of environmental data have been collected in the upper Washita River basin in southwestern Oklahoma. However, to date these data have not been compiled into a format that can be comprehensively queried for the purpose of evaluating the effects of various conservation practices implemented to reduce agricultural runoff and erosion in parts of the upper Washita River basin. This U.S. Geological Survey publication, 'Digital atlas of the upper Washita River basin, southwestern Oklahoma' was created to assist with environmental analysis. This atlas contains 30 spatial data sets that can be used in environmental assessment and decision making for the upper Washita River basin. This digital atlas includes U.S. Geological Survey sampling sites and associated water-quality, biological, water-level, and streamflow data collected from 1903 to 2005. The data were retrieved from the U.S. Geological Survey National Water Information System database on September 29, 2005. Data sets are from the Geology, Geography, and Water disciplines of the U.S. Geological Survey and cover parts of Beckham, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Kiowa, and Washita Counties in southwestern Oklahoma. A bibliography of past reports from the U.S. Geological Survey and other State and Federal agencies from 1949 to 2004 is included in the atlas. Additionally, reports by Becker (2001), Martin (2002), Fairchild and others (2004), and Miller and Stanley (2005) are provided in electronic format.

  2. Local facilitation, bistability and transitions in arid ecosystems

    NARCIS (Netherlands)

    Kefi, S.; Rietkerk, M.; Baalen, van M.; Loreau, M.

    2007-01-01

    Arid ecosystems are liable to undergo sudden discontinuous transitions from a vegetated to a desert state as a result of human pressure and climate change. A predictive framework about the conditions under which such transitions occur is lacking. Here, we derive and analyze a general model describin

  3. Extreme climatic events shape arid and semiarid ecosystems

    NARCIS (Netherlands)

    Holmgren, M.; Stapp, P.; Dickman, C.; Gracia, C.; Graham, S.

    2006-01-01

    Climatic changes associated with the El Nino Southern Oscillation (ENSO) can have a dramatic impact on terrestrial ecosystems worldwide, but especially on arid and semiarid systems, where productivity is strongly limited by precipitation. Nearly two decades of research, including both short-term exp

  4. Evaporation as the transport mechanism of metals in arid regions.

    Science.gov (United States)

    Lima, Ana T; Safar, Zeinab; Loch, J P Gustav

    2014-09-01

    Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high evaporation rates in arid regions, groundwater quality is not threatened and all soil contamination issues tend to be overlooked. But if soil contamination happens, where do contaminants go? This study tests the hypothesis of upward metal movement in soils when evaporation is the main transport mechanism. Laboratory evaporation tests were carried out with heavy metal spiked Saudi soil, using circulation of air as the driving force (Fig. 1). Main results show that loamy soil retains heavy metals quite well while evaporation drives heavy metals to the surface of a sandy soil. Evaporation transports heavy metals upward in sandy soils of arid regions, making them accumulate at the soil surface. Sand being the dominating type of soil in arid regions, soils can then be a potential source of contaminated aerosols and atmospheric pollution - a transboundary problem. Some other repercussions for this problem are foreseen, such as the public ingestion or inhalation of dust.

  5. Agave Lechuguilla as a Potential Biomass Source in Arid Areas

    Directory of Open Access Journals (Sweden)

    Ahmad Houri

    2016-03-01

    Full Text Available Biomass productivity presents a challenging problem in arid and semi-arid areas.  Despite a large need for energy in the form of solid biomass, liquid fuel or needs for animal feed, these regions remain largely unproductive.  A convenient way to overcome this challenge is to utilize plants with high water-use efficiency.  Agave lechuguilla is an example of a highly productive (3.8 tons ha-1 yr-1 desert plant that holds the potential for producing biomass with minimal water resources.  For this purpose, a global suitability map has been developed showing areas where this plant can be planted, and its productivity was assessed.  A Maxent model was used and was further refined by excluding protected areas and used lands (urban, agriculture, etc...  Productivity assessment provides a good way forward for prioritizing the regional utilization of this plant.   This study provides an initial analysis for the use of arid and semi-arid regions for biomass production.  Results indicate the potential generation of 93.8 million tons per year of dry biomass if the suitable areas were fully utilized.  The analytical method can be readily applied to other potential plant species to optimize the use of certain areas.

  6. Evaporation as the transport mechanism of metals in arid regions

    NARCIS (Netherlands)

    Lima, A.T.; Safar, Z.; Loch, J.P.G.

    2014-01-01

    Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high evapora

  7. Trends and responses to global change of China's arid regions

    Institute of Scientific and Technical Information of China (English)

    Weixi YANG

    2009-01-01

    Ⅰ analyzed and elaborated the trends in and responses to global change in arid regions of China, from the perspective of nine variables, i.e., temperature, precipitation, river runoff, melting glaciers, water level of lakes, wind power and evaporation, vegetation, oases, and desertification. The climate and hydrology data Ⅰ citedrepresent many years of observations. Ⅰ conclude that, since the 1980s, the climate in arid regions of China has clearly changed with rising temperatures and precipitation in most areas. Wind power and the number of galestorm days have continuously decreased, which resulted in an improvement of humid conditions and increases in river discharge and water levels of lakes. Simultaneously, vegetation also has improved and the process of deserti-fication has essentially been arrested. Although there are some unfavorable developments, such as decreased river flows or flow interruptions and downstream oases have suffered from degradation, these incidental cases should not distract our attention from the generally favorable trends during the middle and late 20th century. These discordant phenomena are not consequences of climate change but rather of unsuitable human activities. Despitea substantial increase in precipitation, the level of the original precipitation was so small that any increase in precipitation was still small. As a result, none of the fundamental conditions such as a scarcity of water resources and precipitation nor the landscape of drought-ridden deserts in the arid regions will change. The vulnerability of the eco-environmental system in the arid regions will not change fundamentally either in the near future.

  8. Simulation of water use and herbage growth in arid regions

    NARCIS (Netherlands)

    Keulen, van H.

    1975-01-01

    The and and semi-arid regions of the world, totalling about 30% of the land surface of the earth, are predominantly used for extensive grazing, as low and erratic rainfall presents too high a risk for arable farming. The population that can be sustained by the animal products -meat, milk or wool- is

  9. Evaporation as the transport mechanism of metals in arid regions

    KAUST Repository

    Lima, Ana T.

    2014-09-01

    Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high evaporation rates in arid regions, groundwater quality is not threatened and all soil contamination issues tend to be overlooked. But if soil contamination happens, where do contaminants go? This study tests the hypothesis of upward metal movement in soils when evaporation is the main transport mechanism. Laboratory evaporation tests were carried out with heavy metal spiked Saudi soil, using circulation of air as the driving force (Fig. 1). Main results show that loamy soil retains heavy metals quite well while evaporation drives heavy metals to the surface of a sandy soil. Evaporation transports heavy metals upward in sandy soils of arid regions, making them accumulate at the soil surface. Sand being the dominating type of soil in arid regions, soils can then be a potential source of contaminated aerosols and atmospheric pollution - a transboundary problem. Some other repercussions for this problem are foreseen, such as the public ingestion or inhalation of dust. © 2014 Elsevier Ltd.

  10. Research on Structure Innovation of Agricultural Organization in China's Southwestern Mountainous Regions

    OpenAIRE

    Du, Qiang; Luo, Min; Wang, Ping

    2012-01-01

    Taking agricultural organization in China's southwestern mountainous regions as research object, on the basis of analysis of the status quo of agricultural organization development in China's southwestern mountainous regions, we use related theoretical knowledge on economics and organization science, we probe into the process of innovation and mechanism of action concerning the structure of agricultural organization in China's southwestern mountainous regions over the past 30 years. Finally w...

  11. Arid land plants: promising new tools for economic development and basic research

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.

    1980-01-01

    An overview is presented of arid land plant development stressing products and plant physiological and ecological concepts unique to arid land plants. Integration of new arid land crops into polyculture management systems is suggested utilizing specialized plant functions, e.g., drought resistance, resistance to salinity, ability to fix nitrogen, frost tolerance and capability to produce a cash crop. Impacts on arid land plant productivity on political systems of developing countries are discussed and recommendations are presented for overcoming institutional constraints facing arid land plant development. (MHR)

  12. Management of nutrients and water in rainfed arid and semi-arid areas. Proceedings of a consultants meeting

    International Nuclear Information System (INIS)

    Sustainable food security is needed for the arid and semi-arid regions of the tropical, subtropical and warm-temperate climatic zones. In these regions the supply of locally grown food is unreliable because much of it is produced in conditions of highly variable rainfall. Even in favourable seasons, these regions re becoming increasingly dependent on imported food. The IAEA's involvement in field studies on soil-water use dates back several years. A five year Co-ordinated Research Project on ''The Use of Nuclear and Related Techniques in Assessment of Irrigation Schedules of Field Crops to Increase Effective Use of Water in Irrigation Projects''. That project, completed in 1995, laid a solid foundation for future research. Because of a scarcity of water in many developing countries and increasing needs for sustainable food security in the face of increasing populations and lack of funds for irrigation schemes of significant dimension, research must focus on improved management of (i) the modest quantities of fertilizers that are available to farmers, (ii) the natural resources that are available to farmers for increasing soil organic matter content, and (iii) rain water. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture held a Consultants Meeting on Management of Nutrients and Water in Rainfed Arid and Semi-Arid Areas for Increasing Crop Production, 26-29 May 1997

  13. Spatial pattern of nitrogen isotopes as an indicator of ecosystem responses to rainfall in semi-arid and arid grasslands

    Science.gov (United States)

    WANG, C.; Bai, E.; Liu, D.; Fang, T. Y.; Jiang, P.; Han, G. X.

    2013-12-01

    Nitrogen (N) is an essential element for plant growth, however, whether it is a limiting factor of plant growth in water-limited areas is still not clear. Here we examined spatial variations of plant and soil stable N isotopes along a 3200 km precipitation gradient and proposed a conceptual model to explain ecosystem responses to increasing precipitation in arid and semi-arid grasslands in China. Soil δ15N increased with increasing MAP in areas with MAP areas with 200 mm 200 mm. In areas with MAP nutrient cycling in arid and semi-arid areas. If future climate change leads to drier climate in dryland, the uncoupled plant and microbial response may cause more N losses and higher ecosystem vulnerability. 3 Soil organic carbon (Soil C, a), total nitrogen (Soil N, b), C/N (c) and δ15N (d) of study sites along a MAP gradient. Relationship between MAP and foliar δ15N (a) and root δ15N (b).

  14. Impacts of climate change on nutrient cycling in semi-arid and arid ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Belnap, J. [National Biological Survey, Moab, UT (United States)

    1995-09-01

    Effective precipitation is a major factor in determining nutrient pathways in different ecosystems. Soil flora and fauna play a critical role in nutrient cycles of all ecosystems. Temperature, timing, and amounts of precipitation affect population composition, activity levels, biomass, and recovery rates from disturbance. Changes in these variables can result in very different inputs and outputs for different nutrients. As a result, areas with less effective precipitation have very different nutrient cycles than more mesic zones. Climate change, therefore, can profoundly affect the nutrient cycles of ecosystems. Nitrogen cycles may be especially sensitive to changes in temperature and to timing and amounts of precipitation. Rainfall contains varying amounts of nitrogen compounds. Changes in amounts of rainfall will change amounts of nitrogen available to these systems. Because rainfall is limited in semi-arid and regions, these systems tend to be more dependent on microbial populations for nitrogen input. Consequently, understanding the effects of climate change on these organisms is critical in understanding the overall effect on ecosystems.

  15. Agave: a biofuel feedstock for arid and semi-arid environments

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Stephen; Martin, Jeffrey; Simpson, June; Wang, Zhong; Visel, Axel

    2011-05-31

    Efficient production of plant-based, lignocellulosic biofuels relies upon continued improvement of existing biofuel feedstock species, as well as the introduction of newfeedstocks capable of growing on marginal lands to avoid conflicts with existing food production and minimize use of water and nitrogen resources. To this end, specieswithin the plant genus Agave have recently been proposed as new biofuel feedstocks. Many Agave species are adapted to hot and arid environments generally unsuitable forfood production, yet have biomass productivity rates comparable to other second-generation biofuel feedstocks such as switchgrass and Miscanthus. Agavesachieve remarkable heat tolerance and water use efficiency in part through a Crassulacean Acid Metabolism (CAM) mode of photosynthesis, but the genes andregulatory pathways enabling CAM and thermotolerance in agaves remain poorly understood. We seek to accelerate the development of agave as a new biofuelfeedstock through genomic approaches using massively-parallel sequencing technologies. First, we plan to sequence the transcriptome of A. tequilana to provide adatabase of protein-coding genes to the agave research community. Second, we will compare transcriptome-wide gene expression of agaves under different environmentalconditions in order to understand genetic pathways controlling CAM, water use efficiency, and thermotolerance. Finally, we aim to compare the transcriptome of A.tequilana with that of other Agave species to gain further insight into molecular mechanisms underlying traits desirable for biofuel feedstocks. These genomicapproaches will provide sequence and gene expression information critical to the breeding and domestication of Agave species suitable for biofuel production.

  16. Phosphorus transformations along a large-scale climosequence in arid and semiarid grasslands of northern China

    Science.gov (United States)

    Feng, Jiao; Turner, Benjamin L.; Lü, Xiaotao; Chen, Zhenhua; Wei, Kai; Tian, Jihui; Wang, Chao; Luo, Wentao; Chen, Lijun

    2016-09-01

    The Walker and Syers model of phosphorus (P) transformations during long-term soil development has been verified along many chronosequences but has rarely been examined along climosequences, particularly in arid regions. We hypothesized that decreasing aridity would have similar effects on soil P transformations as time by increasing the rate of pedogenesis. To assess this, we examined P fractions in arid and semiarid grassland soils (0-10 cm) along a 3700 km aridity gradient in northern China (aridity between 0.43 and 0.97, calculated as 1 - [mean annual precipitation/potential evapotranspiration]). Primary mineral P declined as aridity decreased, although it still accounted for about 30% of the total P in the wettest sites. In contrast, the proportions of organic and occluded P increased as aridity decreased. These changes in soil P composition occurred in parallel with marked shifts in soil nutrient stoichiometry, with organic carbon:organic P and nitrogen:organic P ratios increasing with decreasing aridity. These results indicate increasing abundance of P relative to carbon or nitrogen along the climosequence. Overall, our results indicate a broad shift from abiotic to biotic control on P cycling at an aridity value of approximately 0.7 (corresponding to about 250 mm mean annual rainfall). We conclude that the Walker and Syers model can be extended to climosequences in arid and semiarid ecosystems and that the apparent decoupling of nutrient cycles in arid soils is a consequence of their pedogenic immaturity.

  17. Modeling the Surface Water-Groundwater Interaction in Arid and Semi-Arid Regions Impacted by Agricultural Activities

    Science.gov (United States)

    Tian, Y.; Wu, B.; Zheng, Y.

    2013-12-01

    In many semi-arid and arid regions, interaction between surface water and groundwater plays an important role in the eco-hydrological system. The interaction is often complicated by agricultural activities such as surface water diversion, groundwater pumping, and irrigation. In existing surface water-groundwater integrated models, simulation of the interaction is often simplified, which could introduce significant simulation uncertainty under certain circumstance. In this study, GSFLOW, a USGS model coupling PRMS and MODFLOW, was improved to better characterize the surface water-groundwater interaction. The practices of water diversion from rivers, groundwater pumping and irrigation are explicitly simulated. In addition, the original kinematic wave routing method was replaced by a dynamic wave routing method. The improved model was then applied in Zhangye Basin (the midstream part of Heihe River Baisn), China, where the famous 'Silk Road' came through. It is a typical semi-arid region of the western China, with extensive agriculture in its oasis. The model was established and calibrated using the data in 2000-2008. A series of numerical experiments were conducted to evaluate the effect of those improvements. It has been demonstrated that with the improvements, the observed streamflow and groundwater level were better reproduced by the model. The improvements have a significant impact on the simulation of multiple fluxes associated with the interaction, such as groundwater discharge, riverbed seepage, infiltration, etc. Human activities were proved to be key elements of the water cycle in the study area. The study results have important implications to the water resources modeling and management in semi-arid and arid basins.

  18. Stable carbon isotope characteristics of different plant species and surface soil in arid regions

    Institute of Scientific and Technical Information of China (English)

    Jianying MA; Wei SUN; Huiwen ZHANG; Dunsheng XIA; Chengbang AN; Fahu CHEN

    2009-01-01

    The stable carbon isotope composition in surface soil organic matter (δ13Csoil) contains integrative information on the carbon isotope composition of the standing terrestrial plants (δ13Cleaf). In order to obtain valuable vegetation information from the δ13C of terrestrial sediment, it is necessary to understand the relationship between the δ13C value in modem surface soil and the standing vegetation. In this paper, we studied the δ13C value in modem surface soil organic matter and standing vegetation in arid areas in China, Australia and the United States. The isotopic discrepancy between δ13Csoil andδ13Cleaf of the standing dominant vegetation was examined in those different arid regions. The results show that the δ13Csoil values were consistently enriched compared to the δ13Cleaf. The δ13Cleaf values were positively correlated with δ13Csoil, which suggests that the interference of microorganisms and hydrophytes on the isotopic composition of surface soil organic matter during soil organic matter formation could be ignored in arid regions. The averaged discrepancy between δ13Csoil and δ13Cleaf is about 1.71%0 in Tamarix L. in the Tarim Basin in China, 1.50 ‰ in Eucalytus near Orange in Australia and 1.22 ‰ in Artemisia in Saratoga in the United States, which are different from the results of other studies. The results indicate that the discrepancies in the δ13C value between surface soil organic matter and standing vegetation were highly influenced by the differences in geophysical location and the dominant species of the studied ecosystems. We suggest that caution should be taken when organic matter δ13C in terrestrial sediment is used to extract paleovegetation information (C3/C4 vegetation composition), as the δ13C in soil organic matter is not only determined by the ratio of C3/C4 species, but also profoundly affected by climate change induced variation in the δ13C in dominant species.

  19. Quantifying the thermal heat requirement of Brassica in assessing biophysical parameters under semi-arid microenvironments

    Science.gov (United States)

    Adak, Tarun; Chakravarty, N. V. K.

    2010-07-01

    Evaluation of the thermal heat requirement of Brassica spp. across agro-ecological regions is required in order to understand the further effects of climate change. Spatio-temporal changes in hydrothermal regimes are likely to affect the physiological growth pattern of the crop, which in turn will affect economic yields and crop quality. Such information is helpful in developing crop simulation models to describe the differential thermal regimes that prevail at different phenophases of the crop. Thus, the current lack of quantitative information on the thermal heat requirement of Brassica crops under debranched microenvironments prompted the present study, which set out to examine the response of biophysical parameters [leaf area index (LAI), dry biomass production, seed yield and oil content] to modified microenvironments. Following 2 years of field experiments on Typic Ustocrepts soils under semi-arid climatic conditions, it was concluded that the Brassica crop is significantly responsive to microenvironment modification. A highly significant and curvilinear relationship was observed between LAI and dry biomass production with accumulated heat units, with thermal accumulation explaining ≥80% of the variation in LAI and dry biomass production. It was further observed that the economic seed yield and oil content, which are a function of the prevailing weather conditions, were significantly responsive to the heat units accumulated from sowing to 50% physiological maturity. Linear regression analysis showed that growing degree days (GDD) could indicate 60-70% variation in seed yield and oil content, probably because of the significant response to differential thermal microenvironments. The present study illustrates the statistically strong and significant response of biophysical parameters of Brassica spp. to microenvironment modification in semi-arid regions of northern India.

  20. Jojoba: North American desert shrub; its ecology, possible commercialization, and potential as an introduction into other arid regions. [Simmondsia chinensis

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, W.H.

    1978-09-01

    Jojoba (Simmondsia chinensis (Link.) Schneid.), a North American desert shrub, is the only plant known to produce a liquid wax in its seed. This substance is chemically similar to the oil from the Sperm whale. Industrial and agronomic uses are described as well as currently known economic factors regarding agronomic production. The plants' present distribution is linked with the winter-spring rains of a Mediterranean type of climate in the Sonoran Desert regions of the United States and Sonora and Baja California in Mexico. It is suggested that other arid regions may be quite suitable to its introduction, particularly portions of the Asir Province in western Saudi Arabia.

  1. Not All Roads Lead to Resilience: a Complex Systems Approach to the Comparative Analysis of Tortoises in Arid Ecosystems

    OpenAIRE

    Thomas E. J. Leuteritz; Ekbia, Hamid R.

    2008-01-01

    The concept of resilience has been widely used in the study of social-ecological systems, with its key components identified as resistance, latitude, and precariousness. We use this concept to examine the differences among three semi-arid regions in terms of these three components. We do this by examining the status of tortoises that occur in the dry spiny forest Madagascar, the Karoo of South Africa, and the Mojave Desert of the United States as an indicator of the health and resilience of t...

  2. Structural controls of Holocene reactivation of the Meers fault, southwestern Oklahoma, from magnetic studies

    Science.gov (United States)

    Jones-Cecil, M.

    1995-01-01

    Holocene reactivation of the aseismic Meers fault in southwestern Oklahoma illustrates the limitation of using the historical seismic record for identifying hazardous faults in the central United States. The 26- to 37-km-long fault sarp is one of the few known scarps recording Holocene movement in the central and eastern United States. Two documented late Holocene slip events, each with about 2.5 m of net slip and estimated Ms ranging from 6 3/4 to 7 1/4 , identify the Meers fault as a potentially hazardous fault. In the present-day strike-slip regional stress field, the observed up-to-the-north Holocene displacement suggests that either the fault continues to dip steeply at depth or the regional stress field is approaching a normal-faulting stress regime. If the former is true, the scarcity of near-vertical faults with similar orientation within the areas of the southern Oklahoma aulacogen implies that few are likely candidates for reactivation. from Author

  3. Structures and sequence stratigraphy of the Miocene successions, southwestern Gulf of Suez, Egypt

    Science.gov (United States)

    Abd El Naby, Ahmed; Abdel-Rahman, Ahmed; Abd El-Aal, Mohamed; Alhamshry, Asmaa

    2016-05-01

    The subsurface structural evolution, facies changes and sequence stratigraphic interpretations of the Miocene successions of the southwestern part of the Gulf of Suez, Egypt, were studied by seismic reflection data of Twenty seven 3D seismic sections supported by the composite, velocity and vertical seismic profiles (VSP) logs of eight wells. Among them five sections and two geoseismic cross sections were selected to reveal the structural framework and depositional history of the study area. The analysis of depth-structure contour maps revealed that the Miocene strata are dissected by two major faults trends: The NW-SE trending faults (Clysmic trend) and the NE-SW trending cross faults running nearly perpendicular to the Clysmic faults. The facies changes of the syn-depositional Miocene units are controlled by the structural framework of the southern part of the Gulf of Suez being evolving diapiric structure of South Gharib Formation. The Miocene units are subdivided into two major 3rd order depositional sequences: S1 and S2.

  4. How Sustainable are Engineered Rivers in Arid Lands?

    Directory of Open Access Journals (Sweden)

    Jurgen Schmandt

    2013-06-01

    Full Text Available Engineered rivers in arid lands play an important role in feeding the world’s growing population. Each continent has rivers that carry water from distant mountain sources to fertile soil downstream where rainfall is scarce. Over the course of the last century most rivers in arid lands have been equipped with large engineering structures that generate electric power and store water for agriculture and cities. This has changed the hydrology of the rivers. In this paper we discuss how climate variation, climate change, reservoir siltation, changes in land use and population growth will challenge the sustainability of engineered river systems over the course of the next few decades. We use the Rio Grande in North America, where we have worked with Mexican and American colleagues, to describe our methodology and results. Similar work is needed to study future water supply and demand in engineered rivers around the world.

  5. On coordinated development of oasis and environment in arid area

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based upon the formation and evolution of oasis and the factors restricting the coordinated development of oasis economy and environment, this paper presents a goal of the development in coordination. It suggests that the sustainable survival and development of oasis could be ensured only if the oasis-desert and water source ecology are managed in a combined way to form a macro system. In light with the above mentioned, the approach to the development of economy and environment of oasis in arid area should depend upon the establishment of an oasis ecological and economic system, which suits the arid environment and promotes the efficiency of resource configuration, stabilizes economic increment and benefits ecological development.

  6. Domesticated proboscidea parviflora: a potential oilseed crop for arid lands

    Energy Technology Data Exchange (ETDEWEB)

    Berry, J.; Bretting, P.K.; Nabhan, G.P.; Weber, C.

    1981-01-01

    Wild and domesticated Proboscidea parviflora were evaluated as oilseed crops for arid lands through chemical and biological analyses. Domesticated plants grown in the Sonoran desert bore seed containing 35-40 per cent oil and 23-27 per cent protein. Yield per hectare was estimated at 1000 kg of oil and 675 kg of protein, quantities which compare favourably with other crops. An ephemeral life cycle and certain characteristics of the fruit and seed allow this plant to grow in xeric habitats unsuitable for many other plants. Several Proboscidea species hybridize with P. parviflora and could be used in future crop breeding. Rapid germination and higher oil and protein content of seed make the domesticated P. parviflora superior to the wild form as a crop. Domesticated P. parviflora thus shows promise as an oilseed crop for the Sonoran Desert and possibly for other arid regions. (Refs. 22).

  7. Arid lands plants as feedstocks for fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, J.J.

    1983-01-01

    The purpose of this paper is to review the recent research on arid-adapted plants that have potential as producers of fuels or chemicals. The major focus will be on plant species that appear to have commercial value. Research on guayule (Parthenium argentatum) and jojoba (Simmondsia chinensis) will be mentioned only briefly, since these plants have been discussed extensively in the literature, and excellent reviews are already in existence. In this review the literature on arid-adapted plants that have potential uses for solid fuels, liquid fuels, and chemical feedstocks is summarized, followed by an overview of the research directions and types of development that are needed in order for bio-energy production systems to reach the commercial stage. 127 references.

  8. Expanding the phenotypic spectrum of ARID1B-mediated disorders and identification of altered cell-cycle dynamics due to ARID1B haploinsufficiency

    DEFF Research Database (Denmark)

    Sim, J. C. H.; White, S. M.; Fitzpatrick, E.;

    2014-01-01

    patient-derived and ARID1B knockdown fibroblasts after serum starvation demonstrated delayed cell cycle re-entry associated with reduced cell number in the S-1 phase. Based on the patient's distinctive phenotype, we ascertained four additional patients and identified heterozygous de novo ARID1B frameshift...

  9. Seasonal Water Availability and Mountain Forest Dynamics in the Southwestern U.S.A.

    Science.gov (United States)

    Brown-Mitic, C. M.; Parajuli, K.; Telewski, F.; Shuttleworth, W. J.

    2007-05-01

    Water availability in the semi arid United States varies seasonally, annually, and on multi-year cycles, affecting mountain forest carbon exchange directly by influencing primary production and respiration and indirectly through drought, forest fires and insect infestation. Explicitly quantifying the carbon-water relationship in mountain island ecosystems depends largely on understanding both the temporal distribution of water availability and the response of the vegetation to seasonal inputs. Understanding how ecosystems, particularly those which are positioned along sensitive vegetation ecotones and steep transitional climate zones, function and respond to perturbations in climatic conditions is critical to our understanding of the expected range of changes that are possible with changes to our climate. What are the possible responses in ecosystem composition, diversity and biotic feedbacks, not only to changes in the amount of precipitation, but also shifts in its' seasonal pattern, frequency distribution and intensity? Southern Arizona provides a natural laboratory with an annual bimodal precipitation pattern, steep transitional climatic zones, sensitive ecotones, with clear demarcation resulting from large elevation and precipitation gradients and high water limiting conditions with extreme climate variability. This presentation highlights the seasonal carbon-water relationship of a coniferous mountain island forest in the Santa Catalina Mountains of Southern Arizona. Hydro-micrometeorological observations from an eddy covariance flux tower made over five years encompass periods of severe multi-year drought punctuated by strong El Nino winter seasons. Distinct seasonal water use efficiency and carbon assimilation highlights the unique dynamics of this ecosystem and provide part of the fundamental reasons for the observed northward migration of semi-arid coniferous species.

  10. Duricrusts and deep-weathering profiles in southwestern wisconsin.

    Science.gov (United States)

    Dury, G H; Knox, J C

    1971-10-15

    Numerous exposures in southwestern Wisconsin display the profiles of relict deep weathering. Crusts are mainly siliceous, but many are ferruginized to some extent. The occurrence of blocky silcrete, thought to be reported for the first time, recalls the profiles in the Australian belt of transition from silcrust to ferricrust. The humid-tropical kind of pedogenesis necessary to effect this transition may have operated as late as the mid-Miocene. In some localities, the action of grotndwater has caused crusting, mottling, and reduction beneath the dolomite low surface moisture.

  11. Soil Ecosystem Degradation of Karst Regions in Southwestern China

    Institute of Scientific and Technical Information of China (English)

    XIE Shi-you; WANG Ju

    2012-01-01

    Deeply influenced by karst geological environment, the structure of the soil ecosystem in the southwest karst area of China is characterized by strong vertical variation and space variation, structural feature of nonrenewable soil, and functional feature of poor circulation of nutrient elements and limited vegetation growth. On the basis of analyzing vulnerability in structure and function of soil ecosystem in China’s southwestern karst regions, we discussed the degradation process and mechanism of soil structure, nutrient, water and microorganism in the course of soil erosion from the perspective of material and energy cycle. Finally, we put forward some recommendations for recovery of degraded soil, transformation and rational utilization of soil.

  12. Evolutionary shifts in habitat aridity predict evaporative water loss across squamate reptiles.

    Science.gov (United States)

    Cox, Christian L; Cox, Robert M

    2015-09-01

    Aridity is an important determinant of species distributions, shaping both ecological and evolutionary diversity. Lizards and snakes are often abundant in deserts, suggesting a high potential for adaptation or acclimation to arid habitats. However, phylogenetic evidence indicates that squamate diversity in deserts may be more strongly tied to speciation within arid habitats than to convergent evolution following repeated colonization from mesic habitats. To assess the frequency of evolutionary transitions in habitat aridity while simultaneously testing for associated changes in water-balance physiology, we analyzed estimates of total evaporative water loss (EWL) for 120 squamate species inhabiting arid, semiarid, or mesic habitats. Phylogenetic reconstructions revealed that evolutionary transitions to and from semiarid habitats were much more common than those between arid and mesic extremes. Species from mesic habitats exhibited significantly higher EWL than those from arid habitats, while species from semiarid habitats had intermediate EWL. Phylogenetic comparative methods confirmed this association between habitat aridity and EWL despite phylogenetic signal in each. Thus, the historical colonization of arid habitats by squamates is repeatedly associated with adaptive changes in EWL. This physiological convergence, which may reflect both phenotypic plasticity and genetic adaptation, has likely contributed to the success of squamates in arid environments.

  13. Wind power variations under humid and arid meteorological conditions

    International Nuclear Information System (INIS)

    Highlights: • It indicates the role of weather parameters’ roles in the wind energy calculation. • Meteorological variables are more significant in arid regions for wind power. • It provides opportunity to take into consideration air density variability. • Wind power is presented in terms of the wind speed, temperature and pressure. - Abstract: The classical wind power per rotor area per time is given as the half product of the air density by third power of the wind velocity. This approach adopts the standard air density as constant (1.23 g/cm3), which ignores the density dependence on air temperature and pressure. Weather conditions are not taken into consideration except the variations in wind velocity. In general, increase in pressure and decrease in temperature cause increase in the wind power generation. The rate of increase in the pressure has less effect on the wind power as compared with the temperature rate. This paper provides the wind power formulation based on three meteorological variables as the wind velocity, air temperature and air pressure. Furthermore, from the meteorology point of view any change in the wind power is expressed as a function of partial changes in these meteorological variables. Additionally, weather conditions in humid and arid regions differ from each other, and it is interesting to see possible differences between the two regions. The application of the methodology is presented for two meteorology stations in Istanbul, Turkey, as representative of the humid regions and Al-Madinah Al-Monawwarah, Kingdom of Saudi Arabia, for arid region, both on daily record bases for 2010. It is found that consideration of air temperature and pressure in the average wind power calculation gives about 1.3% decrease in Istanbul, whereas it is about 13.7% in Al-Madinah Al-Monawwarah. Hence, consideration of meteorological variables in wind power calculations becomes more significant in arid regions

  14. Semi-arid development: competitiveness factors in biodiesel productive chain

    OpenAIRE

    Breno Barros Telles do Carmo; Dmontier Pinheiro Aragão; Heráclito Lopes Jaguaribe Pontes; Bruno Magalhães Ribeiro; Marcos Ronaldo Albertin

    2009-01-01

    The new global market competitiveness considerer the competition between productive chains (PC) or supply chains, not just between enterprises. In this case, it can be observed collaboration and cooperation enterprises that dispute with others productives chain. The PC competitiveness can be impaired if is subject by inhibitors factors, that can impairer the performance. This paper analyses these competitiveness factors inhibitors in biodiesel productive chain (CPB) in semi-arid area: exporte...

  15. A Feasibility Study of Geologic Water Storage in Arid Regions

    Science.gov (United States)

    Fairley, J. P.; Preuit, T.

    2001-05-01

    An important control on the carrying capacity of arid and semi-arid regions is the ability to develop and maintain a reliable water supply for domestic and agricultural use. In the semi-arid highlands of southern Peru, the pre-Columbian Incas developed a technique of collecting and storing basin yields by controlling the discharge boundary of an existing aquifer. This water resource management strategy has been dubbed "Geologic Water Storage" (Fairley, in review). Yield from at least one such system near Cuzco, Peru, has provided a reliable source of irrigation water for rural farmers to the present day. The geologic water storage systems of southern Peru suggested the possibility of developing a similar system to water stock in rural Idaho. Annual precipitation in Idaho is about one-third that of southern Peru, and obtaining an adequate stock water supply is often problematic. The application of a simple lumped capacitance model to a selected basin in central Idaho showed that it may be physically and economically feasible to modify the basin characteristics to prolong water availability at the site. A more detailed study of this problem, that includes field characterization of the site, is necessary to substantiate the model results. If further studies and field trials confirm the viability of geologic water storage, this approach may find applications in many rural and developing areas, both nationally and internationally.

  16. Saline dust storms and their ecological impacts in arid regions

    Institute of Scientific and Technical Information of China (English)

    Jilili; Abuduwaili

    2010-01-01

    In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In this study,saline dust storms are reviewed systematically from the aspects of con-cept,general characteristics,conditions of occurrence,distribution and ecological impact.Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions;large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence;there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion;and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions.An under-standing of saline dust storms is important to guide disaster prevention and ecological rehabilitation.

  17. Characteristics of the volatile organic compounds -- Arid Integrated Demonstration Site

    International Nuclear Information System (INIS)

    The Volatile Organic Compounds -- Arid Integrated Demonstration Program (VOC-Arid ID) is targeted at demonstration and testing of technologies for the evaluation and cleanup of volatile organic compounds and associated contaminants at arid DOE sites. The initial demonstration site is an area of carbon tetrachloride (CCl4) contamination located near the center of the Hanford Site. The movement of CCl4 and other volatile organic contaminants in the subsurface is very complex. The problem at the Hanford Site is further complicated by the concurrent discharge of other waste constituents including acids, lard oil, organic phosphates, and transuranic radionuclides. In addition, the subsurface environment is very complex, with large spatial variabilities in hydraulic properties. A thorough understanding of the problem is essential to the selection of appropriate containment, retrieval, and/or in situ remedial technologies. The effectiveness of remedial technologies depends on knowing where the contaminants are, how they are held up in a given physical and chemical subsurface environment; and knowing the physical, chemical, and microbiological changes that are induced by the various remedial technologies

  18. Hydrogeologic subdivision of the Wolfcamp series and Pennsylvanian system of eastern Texas Panhandle, north-central Texas, and southwestern Oklahoma

    International Nuclear Information System (INIS)

    The Pennsylvanian-Wolfcamp section in the Palo Duro Basin includes brine aquifers that are considered to be the most important ground-water flow paths in the deep-basin system. This report is the fifth in a series providing summary documentation of studies that subdivide the section into hydrogeologic units based on their judged relative capacities for transmitting water. This report extends the hydrogeologic study area to the eastern Texas Panhandle, north-central Texas, and southwestern Oklahoma. It includes 37 counties in Texas and Oklahoma. Underground patterns of rock distribution are delineated from a hydrologic perspective and at a level of detail appropriate for numerical modeling of regional ground-water flow. Hydrogeologic units are defined and characterized so that appropriate porosity and permeability values can be assigned to each unit during construction of the numerical models (not part of this study), and so that modelers can combine units where necessary. In this study, hydrogeologic units have been defined as mappable, physically continuous rock bodies that function in bulk as water-transmitting or water-retarding units relative to adjacent rocks. Interpretations are made primarily from geophysical logs. Hydrologic characteristics are assessed on the basis of properties typically associated with certain lithologies (e.g., sandstones are more pervious than shales) and on the basis of gross variations in effective porosity (particularly in carbonate sequences). 44 refs., 32 figs., 1 tab

  19. Land use change and carbon cycle in arid and semi-arid lands of East and Central Asia

    Institute of Scientific and Technical Information of China (English)

    Togtohyn; Chuluun; Dennis; Ojima

    2002-01-01

    Dramatic changes in land use have occurred in arid and semi-arid landsof Asia during the 20th century. Grassland conversion into croplands and ecosystem degradation is widespread due to the high growth rate of human population and political reforms of pastoral systems. Rangeland degradation made many parts of this region vulnerable to environmental and political changes. The collapse of the livestock sector in some states of central Asia, expansion of livestock inChina and intensive degradation of grasslands in China are examples of the responses of pastoral systems to these changes over the past decades. Carbon dynamics in this region is highly variable in space and time. Land use/cover changes with widespread reduction of forest and grasslands increased carbon emission from the region.

  20. Preliminary Risk Assessment of the Southwestern Willow Flycatcher (Empidonax traillii extimus) at the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D.; Mullen, M.A.; Foxx, T.S.

    1998-10-01

    The southwestern willow flycatcher (Empidonax traillii extimus) is the fourth threatened or endangered species to undergo a preliminary assessment for estimating potential risk from environmental contaminants at the Los Alamos National Laboratory. The assessments are being conducted as part of a three-year project to develop a habitat management plan for threatened and endangered species and species of concern at the Laboratory. For the preliminary assessment, estimated doses were compared against toxicity reference values to generate hazard indices (HIs). This assessment included a measure of cumulative effects from multiple contaminants (radionuclides, metals, and organic chemicals) to 100 simulated nest sites located within flycatcher potential habitat. Sources of contaminant values were 10,000-ft{sup 2} grid cells within an Ecological Exposure Unit (EEU). This EEU was estimated around the potential habitat and was based on the maximum home range for the fly catcher identified in the scientific literature. The tools used included a custom FORTRAN program, ECORSK5, and a geographic information system. Food consumption and soil ingestion contaminant pathways were addressed in the assessment. Using a four-category risk evaluation, HI results indicate no appreciable impact is expected to the southwestern willow flycatcher. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, flycatcher habitat, facility siting, and/or facility operations in order to maintain low levels of risk from contaminants.

  1. Hourly Wind Speed Interval Prediction in Arid Regions

    Science.gov (United States)

    Chaouch, M.; Ouarda, T.

    2013-12-01

    The long and extended warm and dry summers, the low rate of rain and humidity are the main factors that explain the increase of electricity consumption in hot arid regions. In such regions, the ventilating and air-conditioning installations, that are typically the most energy-intensive among energy consumption activities, are essential for securing healthy, safe and suitable indoor thermal conditions for building occupants and stored materials. The use of renewable energy resources such as solar and wind represents one of the most relevant solutions to overcome the increase of the electricity demand challenge. In the recent years, wind energy is gaining more importance among the researchers worldwide. Wind energy is intermittent in nature and hence the power system scheduling and dynamic control of wind turbine requires an estimate of wind energy. Accurate forecast of wind speed is a challenging task for the wind energy research field. In fact, due to the large variability of wind speed caused by the unpredictable and dynamic nature of the earth's atmosphere, there are many fluctuations in wind power production. This inherent variability of wind speed is the main cause of the uncertainty observed in wind power generation. Furthermore, producing wind power forecasts might be obtained indirectly by modeling the wind speed series and then transforming the forecasts through a power curve. Wind speed forecasting techniques have received substantial attention recently and several models have been developed. Basically two main approaches have been proposed in the literature: (1) physical models such as Numerical Weather Forecast and (2) statistical models such as Autoregressive integrated moving average (ARIMA) models, Neural Networks. While the initial focus in the literature has been on point forecasts, the need to quantify forecast uncertainty and communicate the risk of extreme ramp events has led to an interest in producing probabilistic forecasts. In short term

  2. Mitigating Climate Change in the Arid Lands of Namibia

    Science.gov (United States)

    Schneider, Martin B.; Sorensen, Marten

    2014-05-01

    Mitigating Climate Change in the Arid Lands of Namibia Namibia is the most arid country south of the Sahara, with scarce rainfall and perennial rivers only at its borders, > 80% of the area relies solely on groundwater. This has had devastating economic effects limiting opportunities for sustainable rural livelihoods that keep the population majority living below the World Bank poverty line (IFAD, 2013). A primary example of climatic variability which affects agrarian productivity is increased bush encroachment of Namibia's arid grazing land. The result has been a severe biodiversity loss, increased desertification and diminished water-use efficiency and underground water tables. Given these factors, Namibia's arid lands provide a unique opportunity to assess and test innovative / appropriate adaptation and mitigation strategies. Working toward sustainable management, restoration, and maintenance of balanced, resilient arid ecosystems in Namibia will also be a means to support and expand economic sectors incl. opportunities for job creation and potentially provide a model for similar arid regions. Main vegetation zones are: desert (46%), savannah (37%), and dry woodlands and forests (17%), i.e. human capacities are already in place. However, overall climate variability appears significantly higher than current plans and policies take into account. To improve livelihoods, reduce poverty, and food insecurity for rural Namibians in marginal/hyper-arid lands through sustainable climate change adaptation these objectives will be implemented: 1. Identify, assess and evaluate indigenous management strategies currently used by rural communities. 2. Capture and assess cultural and gender dimensions of management strategies within stakeholder groups using participatory approaches. 3. Determine science-based alternatives for adaptive land management strategies and test their acceptability to local communities and within the current policy framework. 4. Integrate identified

  3. Spatiotemporal analysis and trends of aridity of Iberian Peninsula (1960-2010)

    Science.gov (United States)

    Paniagua, Luis L.; García, Abelardo; Moral, Francisco J.; Rebollo, Francisco J.

    2016-04-01

    In this study the aridity of the Iberian Peninsula was analysed, taking into account 45 stations in Spain and Portugal from 1960 to 2010. The De Martonne Index was considered. The goal of this study was to explore the spatial distribution and to determine monotonic trends and shift changes in annual aridity by using the Mann-Kendall test and the Seńs estimator. The spatially interpolated maps of the aridity indice were generated using the ordinary kriging algorithm in a geographic information system (GIS) environment. A great variability for Martonne Index was found, gathering from semiarid climates to extremely humid, although the former being the dominant type. 41 temporal series showed decreasing tendencies, 15 of them significant, belonging to all climate types, which indicates a increase in aridity during the research period. A shift in the aridity tendency has been observed around 1979, and a period of greater aridity started since.

  4. VOC-Arid Integrated Demonstration guide to preparation of demonstration documents

    International Nuclear Information System (INIS)

    This guide has been prepared by Demonstration Operations of the Volatile Organic Compound-Arid Integrated Demonstration (VOC-Arid ID). Its purpose is to describe demonstration documents, designate responsibilities for these documents, and guide the Principal Investigator (PI) and others in their preparation. The main emphasis of this guide is to describe the documentation required of the PI. However, it does cover some of the responsibilities of other members of the VOC-Arid ID team. The VOC-Arid ID is one of several US Department of Energy (DOE) integrated demonstrations designed to support the demonstration of emerging environmental management and restoration technologies. The principal objective of the VOC-Arid ID is to identify, develop, and demonstrate new and innovative technologies for environmental restoration at arid or semiarid sites containing volatile organic compounds with or without associated contamination (e.g., radionuclides and metals)

  5. What influences climate and glacier change in southwestern China?

    Science.gov (United States)

    Yasunari, Teppei J.

    2011-12-01

    The subject of climate change in the Tibetan Plateau (TP) and Himalayas has taken on increasing importance because of the availability of water resources from their mountain glaciers (Immerzeel et al 2010). Many of the glaciers over these regions have been retreating, while some are advancing and stable (Yao et al 2004, Scherler et al 2011). Other studies report that some glaciers in the Himalayas show acceleration of their shrinkage (e.g., Fujita and Nuimura 2011). However, the causes of glacier melting are still difficult to grasp because of the complexity of climatic change and its influence on glacier issues. Despite this, it is vital that we pursue further study to enable future predictions of glacier changes. The paper entitled 'Climate and glacier change in southwestern China during the past several decades' by Li et al (2011) provided carefully analyzed, quality controlled, long-term data on atmospheric temperature and precipitation during the period 1961-2008. The data were obtained from 111 Chinese stations. The researchers performed systematic analyses of temperature and precipitation over the whole southwestern Chinese domain. They discussed those changes in terms of other meteorological components such as atmospheric circulation patterns, radiation and altitude difference, and then showed how these factors could contribute to climate and glacier changes in the region. Air temperature and precipitation are strongly associated with glacier mass balance because of heat balance and the addition of mass when it snows. Temperature warming trends over many places in southwestern China were unequivocally dominant in all seasons and at higher altitudes. This indicates that the heat contribution to the glaciers has been increasing. On the other hand, precipitation has a wider variability in time and space. It is more difficult to clearly understand the effect of precipitation on the climate and glacier melting characteristics in the whole of southwestern China

  6. Regional Cost Estimates for Reclamation Practices on Arid and Semiarid Lands

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler

    2002-02-01

    The U.S. Army uses the Integrated Training Area Management program for managing training land. One of the major objectives of the Integrated Training Area Management program has been to develop a method for estimating training land carrying capacity in a sustainable manner. The Army Training and Testing Area Carrying Capacity methodology measures training load in terms of Maneuver Impact Miles. One Maneuver Impact Mile is the equivalent impact of an M1A2 tank traveling one mile while participating in an armor battalion field training exercise. The Army Training and Testing Area Carrying Capacity methodology is also designed to predict land maintenance costs in terms of dollars per Maneuver Impact Mile. The overall cost factor is calculated using the historical cost of land maintenance practices and the effectiveness of controlling erosion. Because land maintenance costs and effectiveness are influenced by the characteristics of the land, Army Training and Testing Area Carrying Capacity cost factors must be developed for each ecological region of the country. Costs for land maintenance activities are presented here for the semiarid and arid regions of the United States. Five ecoregions are recognized, and average values for reclamation activities are presented. Because there are many variables that can influence costs, ranges for reclamation activities are also presented. Costs are broken down into six major categories: seedbed preparation, fertilization, seeding, planting, mulching, and supplemental erosion control. Costs for most land reclamation practices and materials varied widely within and between ecological provinces. Although regional cost patterns were evident for some practices, the patterns were not consistent between practices. For the purpose of estimating land reclamation costs for the Army Training and Testing Area Carrying Capacity methodology, it may be desirable to use the ''Combined Average'' of all provinces found in the last

  7. Regional Cost Estimates for Reclamation Practices on Arid and Semiarid Lands; TOPICAL

    International Nuclear Information System (INIS)

    The U.S. Army uses the Integrated Training Area Management program for managing training land. One of the major objectives of the Integrated Training Area Management program has been to develop a method for estimating training land carrying capacity in a sustainable manner. The Army Training and Testing Area Carrying Capacity methodology measures training load in terms of Maneuver Impact Miles. One Maneuver Impact Mile is the equivalent impact of an M1A2 tank traveling one mile while participating in an armor battalion field training exercise. The Army Training and Testing Area Carrying Capacity methodology is also designed to predict land maintenance costs in terms of dollars per Maneuver Impact Mile. The overall cost factor is calculated using the historical cost of land maintenance practices and the effectiveness of controlling erosion. Because land maintenance costs and effectiveness are influenced by the characteristics of the land, Army Training and Testing Area Carrying Capacity cost factors must be developed for each ecological region of the country. Costs for land maintenance activities are presented here for the semiarid and arid regions of the United States. Five ecoregions are recognized, and average values for reclamation activities are presented. Because there are many variables that can influence costs, ranges for reclamation activities are also presented. Costs are broken down into six major categories: seedbed preparation, fertilization, seeding, planting, mulching, and supplemental erosion control. Costs for most land reclamation practices and materials varied widely within and between ecological provinces. Although regional cost patterns were evident for some practices, the patterns were not consistent between practices. For the purpose of estimating land reclamation costs for the Army Training and Testing Area Carrying Capacity methodology, it may be desirable to use the ''Combined Average'' of all provinces found in the last row of each table

  8. Quantitative assessment and analysis on the dynamic change of ecological capital in arid areas

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi; ZHANG Qing; ZHOU Kefa; SUN Li

    2006-01-01

    Ecological capital is the summation of the direct value of biological resources and the ecological service function value of ecosystems. Under the support of RS, GPS and GIS, in this paper the RS-based quantitative measurement model of assessing ecological capital is developed based on the traditional ecology theory and the research on the value of ecological capital per unit area by using the ecological parameters including Landsat TM data,CBERS satellite data, meteorological data, MODIS satellite data, land cover data and field-measured data. A case study on the spatiotemporal distribution of ecological capital in Changji Hui Autonomous Prefecture in 1990, 1995 and 2003 is carried out, and the dynamic change of ecological capital in the prefecture is measured and compared with GDP. The maps of the spatial distribution of ecological capital in the study area are charted, and the characteristics of spatial distribution of ecological capital are analyzed.The results show that the values of ecological capital in the prefecture in 1990, 1995 and 2003 were 1.47368×1011, 1.661 60×1011 and 1.77895×1011yuan RMB (hereafter referred to as yuan) respectively, and that in spatial distribution, the ecological capital decreases from the alpine zones to the plains and from the oases to the deserts, which accords with the zonal distribution of vegetation in arid areas.The measured results can more objectively reflect the ecological capital and its spatial distribution in arid areas, provide an ideal foundation for further study in the future, and can also be combined with the study on service functions of ecosystems and the regional planning as an important basis of regional planning.

  9. Outcrop Groundwater Prospecting, Drilling, and Well Construction in Hard Rocks in Semi-arid Regions

    OpenAIRE

    Chambel, António

    2014-01-01

    This chapter presents some recommendations for prospecting, drilling and well construction in hard rocks in semi-arid regions. Considering that these conditions are present in many countries where technology is not always available, the chapter concentrates on the most basic and simple methods to plan where best to drill and maximize success through the direct observation of rock types, weathering and fracturing. The advantage for the geologist and hydrogeologist in an arid or semi-arid envir...

  10. Analysis and evaluation of tillage on an alfisol ina semi-arid tropical region of India

    OpenAIRE

    Klaij, M C

    1983-01-01

    Tillage field experiments were conducted on Alfisols in a semi-arid tropical environment in India. The research was conducted within the framework of the Farming Systems Research Program of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).To put the experiments into perspective, a general review is given in chapter 2 on the environment of the semi-arid tropics, its problems and the research related to agricultural production. Rainfed agriculture has failed to pro...

  11. ARID1A immunohistochemistry improves outcome prediction in invasive urothelial carcinoma of urinary bladder.

    Science.gov (United States)

    Faraj, Sheila F; Chaux, Alcides; Gonzalez-Roibon, Nilda; Munari, Enrico; Ellis, Carla; Driscoll, Tina; Schoenberg, Mark P; Bivalacqua, Trinity J; Shih, Ie-Ming; Netto, George J

    2014-11-01

    AT-rich interactive domain 1A (ARID1A) is tumor suppressor gene that interacts with BRG1 adenosine triphosphatase to form a SWI/SNF chromatin remodeling protein complex. Inactivation of ARID1A has been described in several neoplasms, including epithelial ovarian and endometrial carcinomas, and has been correlated with prognosis. In the current study, ARID1A expression in urothelial carcinoma (UC) of the bladder and its association with clinicopathological parameters and outcome are addressed. Five tissue microarrays were constructed from 136 cystectomy specimens performed for UC at our institution. Nuclear ARID1A staining was evaluated using immunohistochemistry. An H-score was calculated as the sum of the products of intensity (0-3) multiplied by extent of expression (0%-100%). Average H-score per case was used for statistical analysis. ARID1A expression was categorized in low and high using Youden index to define the cut point. ARID1A expression significantly increased from normal to noninvasive UC to invasive UC. For both tumor progression and cancer death, Youden index yielded an H-score of 288 as the optimal cut point for ARID1A expression. Low ARID1A expression showed a tendency for lower risk of tumor progression and cancer mortality. Adding ARID1A expression to pathologic features offers a better model for predicting outcome than pathologic features alone. Low ARID1A expression was more frequently seen in earlier stage disease. There was a tendency for low ARID1A expression to predict better outcome. More importantly, the findings indicate that adding ARID1A expression to pathologic features increases the goodness of fit of the predictive model. PMID:25175170

  12. Organic Matter and Water Addition Enhance Soil Respiration in an Arid Region

    OpenAIRE

    Liming Lai; Jianjian Wang; Yuan Tian; Xuechun Zhao; Lianhe Jiang; Xi Chen; Yong Gao; Shaoming Wang; Yuanrun Zheng

    2013-01-01

    Climate change is generally predicted to increase net primary production, which could lead to additional C input to soil. In arid central Asia, precipitation has increased and is predicted to increase further. To assess the combined effects of these changes on soil CO2 efflux in arid land, a two factorial manipulation experiment in the shrubland of an arid region in northwest China was conducted. The experiment used a nested design with fresh organic matter and water as the two controlled par...

  13. Late Neogene and Early Quaternary Paleoenvironmental and Paleoclimatic Conditions in Southwestern Europe: Isotopic Analyses on Mammalian Taxa

    Science.gov (United States)

    Domingo, Laura; Koch, Paul L.; Hernández Fernández, Manuel; Fox, David L.; Domingo, M. Soledad; Alberdi, María Teresa

    2013-01-01

    Climatic and environmental shifts have had profound impacts on faunal and floral assemblages globally since the end of the Miocene. We explore the regional expression of these fluctuations in southwestern Europe by constructing long-term records (from ∼11.1 to 0.8 Ma, late Miocene–middle Pleistocene) of carbon and oxygen isotope variations in tooth enamel of different large herbivorous mammals from Spain. Isotopic differences among taxa illuminate differences in ecological niches. The δ13C values (relative to VPDB, mean −10.3±1.1‰; range −13.0 to −7.4‰) are consistent with consumption of C3 vegetation; C4 plants did not contribute significantly to the diets of the selected taxa. When averaged by time interval to examine secular trends, δ13C values increase at ∼9.5 Ma (MN9–MN10), probably related to the Middle Vallesian Crisis when there was a replacement of vegetation adapted to more humid conditions by vegetation adapted to drier and more seasonal conditions, and resulting in the disappearance of forested mammalian fauna. The mean δ13C value drops significantly at ∼4.2−3.7 Ma (MN14–MN15) during the Pliocene Warm Period, which brought more humid conditions to Europe, and returns to higher δ13C values from ∼2.6 Ma onwards (MN16), most likely reflecting more arid conditions as a consequence of the onset of the Northern Hemisphere glaciation. The most notable feature in oxygen isotope records (and mean annual temperature reconstructed from these records) is a gradual drop between MN13 and the middle Pleistocene (∼6.3−0.8 Ma) most likely due to cooling associated with Northern Hemisphere glaciation. PMID:23717470

  14. Late neogene and early quaternary paleoenvironmental and paleoclimatic conditions in southwestern Europe: isotopic analyses on mammalian taxa.

    Science.gov (United States)

    Domingo, Laura; Koch, Paul L; Hernández Fernández, Manuel; Fox, David L; Domingo, M Soledad; Alberdi, María Teresa

    2013-01-01

    Climatic and environmental shifts have had profound impacts on faunal and floral assemblages globally since the end of the Miocene. We explore the regional expression of these fluctuations in southwestern Europe by constructing long-term records (from ~11.1 to 0.8 Ma, late Miocene-middle Pleistocene) of carbon and oxygen isotope variations in tooth enamel of different large herbivorous mammals from Spain. Isotopic differences among taxa illuminate differences in ecological niches. The δ(13)C values (relative to VPDB, mean -10.3 ± 1.1‰; range -13.0 to -7.4‰) are consistent with consumption of C3 vegetation; C4 plants did not contribute significantly to the diets of the selected taxa. When averaged by time interval to examine secular trends, δ(13)C values increase at ~9.5 Ma (MN9-MN10), probably related to the Middle Vallesian Crisis when there was a replacement of vegetation adapted to more humid conditions by vegetation adapted to drier and more seasonal conditions, and resulting in the disappearance of forested mammalian fauna. The mean δ(13)C value drops significantly at ~4.2-3.7 Ma (MN14-MN15) during the Pliocene Warm Period, which brought more humid conditions to Europe, and returns to higher δ(13)C values from ~2.6 Ma onwards (MN16), most likely reflecting more arid conditions as a consequence of the onset of the Northern Hemisphere glaciation. The most notable feature in oxygen isotope records (and mean annual temperature reconstructed from these records) is a gradual drop between MN13 and the middle Pleistocene (~6.3-0.8 Ma) most likely due to cooling associated with Northern Hemisphere glaciation.

  15. Late neogene and early quaternary paleoenvironmental and paleoclimatic conditions in southwestern Europe: isotopic analyses on mammalian taxa.

    Directory of Open Access Journals (Sweden)

    Laura Domingo

    Full Text Available Climatic and environmental shifts have had profound impacts on faunal and floral assemblages globally since the end of the Miocene. We explore the regional expression of these fluctuations in southwestern Europe by constructing long-term records (from ~11.1 to 0.8 Ma, late Miocene-middle Pleistocene of carbon and oxygen isotope variations in tooth enamel of different large herbivorous mammals from Spain. Isotopic differences among taxa illuminate differences in ecological niches. The δ(13C values (relative to VPDB, mean -10.3 ± 1.1‰; range -13.0 to -7.4‰ are consistent with consumption of C3 vegetation; C4 plants did not contribute significantly to the diets of the selected taxa. When averaged by time interval to examine secular trends, δ(13C values increase at ~9.5 Ma (MN9-MN10, probably related to the Middle Vallesian Crisis when there was a replacement of vegetation adapted to more humid conditions by vegetation adapted to drier and more seasonal conditions, and resulting in the disappearance of forested mammalian fauna. The mean δ(13C value drops significantly at ~4.2-3.7 Ma (MN14-MN15 during the Pliocene Warm Period, which brought more humid conditions to Europe, and returns to higher δ(13C values from ~2.6 Ma onwards (MN16, most likely reflecting more arid conditions as a consequence of the onset of the Northern Hemisphere glaciation. The most notable feature in oxygen isotope records (and mean annual temperature reconstructed from these records is a gradual drop between MN13 and the middle Pleistocene (~6.3-0.8 Ma most likely due to cooling associated with Northern Hemisphere glaciation.

  16. Estimation of soil moisture-thermal infrared emissivity relation in arid and semi-arid environments using satellite observations

    Science.gov (United States)

    Grazia Blasi, Maria; Masiello, Guido; Serio, Carmine; Venafra, Sara; Liuzzi, Giuliano; Dini, Luigi

    2016-04-01

    The retrieval of surface parameters is very important for various aspects concerning the climatological and meteorological context. At this purpose surface emissivity represents one of the most important parameters useful for di fferent applications such as the estimation of climate changes and land cover features. It is known that thermal infrared (TIR) emissivity is aff ected by soil moisture, but there are very few works in literature on this issue. This study is aimed to analyze and fi nd a relation between satellite soil moisture data and TIR emissivity focusing on arid and semi-arid environments. These two parameters, together with the land surface temperature, are fundamental for a better understanding of the physical phenomena implied in the soil-atmosphere interactions and the surface energy balance. They are also important in several fi elds of study, such as climatology, meteorology, hydrology and agriculture. In particular, there are several studies stating a correlation between soil moisture and the emissivity at 8-9 μ m in desertic soils, which corresponds to the quartz Reststrahlen, a feature which is typical of sandy soils. We investigated several areas characterized by arid or semi-arid environments, focusing our attention on the Dahra desert (Senegal), and on the Negev desert (Israel). For the Dahra desert we considered both in situ, provided by the International Soil Moisture Network, and satellite soil moisture data, from ASCAT and AMSR-E sensors, for the whole year 2011. In the case of the Negev desert soil moisture data are derived from ASCAT observations and we computed a soil moisture index from a temporal series of SAR data acquired by the Cosmo-SkyMed constellation covering a period of six months, from June 2015 to November 2015. For both cases soil moisture data were related to the retrieved TIR emissivity from the geostationary satellite SEVIRI in three di erent spectral channels, at 8.7 μm, 10.8 μ m and 12 μ m. A Kalman lter

  17. Applicability of passive compost bioreactors for treatment of extremely acidic and saline waters in semi-arid climates.

    Science.gov (United States)

    Biermann, Vera; Lillicrap, Adam M; Magana, Claudia; Price, Barry; Bell, Richard W; Oldham, Carolyn E

    2014-05-15

    Extremely acidic and saline groundwater occurs naturally in south-western Australia. Discharge of this water to surface waters has increased following extensive clearing of native vegetation for agriculture and is likely to have negative environmental impacts. The use of passive treatment systems to manage the acidic discharge and its impacts is complicated by the region's semi-arid climate with hot dry summers and resulting periods of no flow. This study evaluates the performance of a pilot-scale compost bioreactor treating extremely acidic and saline drainage under semi-arid climatic conditions over a period of 2.5 years. The bioreactor's substrate consisted of municipal waste organics (MWO) mixed with 10 wt% recycled limestone. After the start-up phase the compost bioreactor raised the pH from ≤3.7 to ≥7 and produced net alkaline outflow for 126 days. The bioreactor removed up to 28 g/m(2)/d CaCO3 equivalent of acidity and acidity removal was found to be load dependent during the first and third year. Extended drying over summer combined with high salinity caused the formation of a salt-clay surface layer on top of the substrate, which was both beneficial and detrimental for bioreactor performance. The surface layer prevented the dehydration of the substrate and ensured it remained waterlogged when the water level in the bioreactor fell below the substrate surface in summer. However, when flow resumed the salt-clay layer acted as a barrier between the water and substrate decreasing performance efficiency. Performance increased again when the surface layer was broken up indicating that the negative climatic impacts can be managed. Based on substrate analysis after 1.5 years of operation, limestone dissolution was found to be the dominant acidity removal process contributing up to 78-91% of alkalinity generation, while bacterial sulfate reduction produced at least 9-22% of the total alkalinity. The substrate might last up to five years before the limestone

  18. Review of several problems on the study of eco-hydrological processes in arid zones

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ecosystem degradation is a common and cardinal environmental problem in arid zones. The change in the eco-hydrological processes is the basic cause responsible for such a problem. The study on the eco-hydrological processes in arid zones has become a forefront and focus of the eco-environmental research. Recent studies on eco-hydrological processes in arid zones show that the primary vegetation pattern and its eco-hydrological effect are of the most stable state of the ecosystem in arid zones. Special water absorption ways of plants in arid zones and the hydraulic lift and reverse hydraulic lift functions of some plants are the key mechanisms to maintain the stability of the ecosystem in arid zones. In the case of water shortage, ensuring ecological water requirement and maintaining proper ecological ground- water table are the prerequisite to keep healthful operation of the ecosystem in arid zones. The paper reviews some advances in the study of eco-hydrological processes in arid zones. It puts forward the concepts of critical ecological water requirement, optimal ecological water requirement and saturated ecological water requirement, and discusses their determination methods. It also emphasizes that the studies on natural vegetation pattern and eco-hydrological effect, on plants with hydraulic lift function, on water sources for plant absorption, on ecological water requirement and ecological groundwater table for different plant species should be strengthened to determine the species composition and pattern suitable for the restoration and reestablishment of vegetation in different arid zones in China.

  19. Targeting EZH2 methyltransferase activity in ARID1A mutated cancer cells is synthetic lethal

    Science.gov (United States)

    Biter, Benjamin G.; Aird, Katherine M.; Garipov, Azat; Li, Hua; Amatangelo, Michael; Kossenkov, Andrew V.; Schultz, David C.; Liu, Qin; Shih, Ie-Ming; Conejo-Garcia, Jose R.; Speicher, David W.; Zhang, Rugang

    2015-01-01

    ARID1A, a chromatin remodeler, shows one of the highest mutation rates across many cancer types. Notably, ARID1A is mutated in over 50% of ovarian clear cell carcinomas, which currently has no effective therapy. To date, clinically applicable targeted cancer therapy based on ARID1A mutational status has not been described. Here we show that inhibition of the EZH2 methyltransferase acts in a synthetic lethal manner in ARID1A mutated ovarian cancer cells. ARID1A mutational status correlates with response to the EZH2 inhibitor. We identified PIK3IP1 as a direct ARID1A/EZH2 target, which is upregulated by EZH2 inhibition and contributes to the observed synthetic lethality by inhibiting PI3K/AKT signaling. Significantly, EZH2 inhibition causes regression of ARID1A mutated ovarian tumors in vivo. Together, these data demonstrate for the first time a synthetic lethality between ARID1A mutation and EZH2 inhibition. They indicate that pharmacological inhibition of EZH2 represents a novel treatment strategy for ARID1A mutated cancers. PMID:25686104

  20. Mitigating Climate Change in the Arid Lands of Namibia

    Science.gov (United States)

    Schneider, Martin B.; Sorensen, Marten

    2014-05-01

    Mitigating Climate Change in the Arid Lands of Namibia Namibia is the most arid country south of the Sahara, with scarce rainfall and perennial rivers only at its borders, > 80% of the area relies solely on groundwater. This has had devastating economic effects limiting opportunities for sustainable rural livelihoods that keep the population majority living below the World Bank poverty line (IFAD, 2013). A primary example of climatic variability which affects agrarian productivity is increased bush encroachment of Namibia's arid grazing land. The result has been a severe biodiversity loss, increased desertification and diminished water-use efficiency and underground water tables. Given these factors, Namibia's arid lands provide a unique opportunity to assess and test innovative / appropriate adaptation and mitigation strategies. Working toward sustainable management, restoration, and maintenance of balanced, resilient arid ecosystems in Namibia will also be a means to support and expand economic sectors incl. opportunities for job creation and potentially provide a model for similar arid regions. Main vegetation zones are: desert (46%), savannah (37%), and dry woodlands and forests (17%), i.e. management strategies currently used by rural communities. 2. Capture and assess cultural and gender dimensions of management strategies within stakeholder groups using participatory approaches. 3. Determine science-based alternatives for adaptive land management strategies and test their acceptability to local communities and within the current policy framework. 4. Integrate identified indigenous knowledge with appropriate science and new emerging technologies to develop a training toolkit of effective strategies relevant to all stakeholders. 5. Utilize training sessions, education workshops, curriculum revisions, and appropriate information and communication technologies (ICTs) including social media outlets to disseminate the toolkit strategies. 6. Apply a modified logic

  1. Strengthening Student Interest and Learning of Watershed Science using a Case-History Investigation of a Rapidly Changing Semi-Arid Watershed

    Science.gov (United States)

    Huth, A. K.; Hall, M. K.

    2007-12-01

    In a changing climate, watershed disturbances such as drought, large-scale wildfires, and extreme rainfall patterns are on the rise, particularly in the southwestern U.S. Yet, at high-school grade levels, hydrology and watershed science get minimal coverage in classrooms. To address this situation, we developed a set of GIS- based student investigations on the affect of natural and human-induced disturbances on watershed hydrology. The case history focuses on the 2003 Aspen Fire in southern Arizona, but also incorporates investigations of undisturbed watersheds. We structured these investigations around recent hydrologic, geologic, and fire data collected by USGS, USFS, and University of Arizona scientists. The investigations encourage students to use Google Earth and MyWorld GIS to learn about the watersheds of the Santa Catalina Mountains in southern Arizona. Students use precipitation and streamflow data to discover the "normal" response of a semi-arid watershed to rainfall. Through spatial visualization and analysis of the data, they learn how and why a semi-arid watershed may become vulnerable to change due to "unusual" conditions. The large-scale Aspen wildfire and subsequent massive debris flows caused watershed instability and were used as teaching tools in these investigations. Field testing has focused on increasing usability and pedagogical effectiveness, whereas external peer reviews have addressed scientific accuracy. We found the overall response to these investigations by both students and teachers to be positive. The benefits of using real, scientific data in combination with spatial visualization tools to teach about a watershed's response to fire were measured using a survey assessment of student learning during field testing.

  2. Anomalous atmospheric circulation and large winter floods in six subregions of the southwestern United States

    OpenAIRE

    Ely, Lisa L.; Enzel, Yehouda; Cayan, Daniel R.

    1992-01-01

    EXTRACT (SEE PDF FOR FULL ABSTRACT): We examined atmospheric circulation conditions conducive to occurrence of winter floods that exceed the 10-year peak discharge on rivers in six hydroclimatic subregions in Arizona, southern Utah, Nevada, and California. ... This relationship between flooding and broad-scale atmospheric patterns in the modern record will aid in paleoclimatic interpretations of paleoflood records over the last few thousand years.

  3. EnviroAtlas - Biodiversity Metrics by 12-digit HUC for the Southwestern United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset was produced by a joint effort of New Mexico State University, US EPA, and the US Geological Survey (USGS) to support research and online...

  4. 2000 years of cultural adaptation to climate change in the Southwestern United States.

    Science.gov (United States)

    Blinman, Eric

    2008-11-01

    Modern concerns with climate change often overlook the extensive history of both climate change and human adaptation over the millennia. While questions of human-climate system causation are important, especially to the extent that our current behavior is driving environmental change, human societies have experienced multiple climate changes in the past, independent of causation. The histories of cultural adaptation to those changes can help us understand the dynamic interaction between climate and society, expanding the possibilities for "proactive adaptation" that may be available to us today. The underlying principles of cultural adaptation are generally independent of the source of the climate change, and the lessons of the past can suggest social and economic paths that can lead toward sustainability and away from collapse.

  5. Coccidioides niches and habitat parameters in the southwestern United States: A matter of scale

    Science.gov (United States)

    Fisher, F.S.; Bultman, M.W.; Johnson, S.M.; Pappagianis, D.; Zaborsky, E.

    2007-01-01

    To determine habitat attributes and processes suitable for the growth of Coccidioides, soils were collected from sites in Arizona, California, and Utah where Coccidioides is known to have been present. Humans or animals or both have been infected by Coccidioides at all of the sites. Soil variables considered in the upper 20 cm of the soil profile included pH, electrical conductivity, salinity, selected anions, texture, mineralogy, vegetation types and density, and the overall geomorphologic and ecological settings. Thermometerswere buried to determine the temperature range in the upper part of the soil where Coccidioides is often found. With the exception of temperature regimes and soil textures, it is striking that none of the other variables or group of variables that might be definitive are indicative of the presence of Coccidioides. Vegetation ranges from sparse to relatively thick cover in lower Sonoran deserts, Chaparral-upper Sonoran brush and grasslands, and Mediterranean savannas and forested foothills. No particular grass, shrub, or forb is definitive. Material classified as very fine sand and silt is abundant in all of the Coccidioides-bearing soils and may be their most common shared feature. Clays are not abundant (less than 10%). All of the examined soil locations are noteworthy as generally 50% of the individuals who were exposed to the dust or were excavating dirt at the sites were infected. Coccidioides has persisted in the soil at a site in Dinosaur National Monument, Utah for 37 years and at a Tucson, Arizona site for 41 years. ?? 2007 New York Academy of Sciences.

  6. Monitoring and analysis of sand dune movement and growth on the Navajo Nation, southwestern United States

    Science.gov (United States)

    Redsteer, Margaret Hiza; Bogle, Rian C.; Vogel, John M.

    2011-01-01

    Recurring drought and rising temperatures have caused reactivation and renewed growth of sand dunes on the lands of the Navajo Nation on the Colorado Plateau. Migrating dunes threaten health, housing, and transportation pathways. U.S. Geological Survey (USGS) scientists are conducting research to better understand the processes of dune growth and movement. This research will provide critical data to the Native peoples of the region in their response to the changing environment.

  7. Divergence among barking frogs (Eleutherodactylus augusti) in the southwestern United States

    Science.gov (United States)

    Goldberg, C.S.; Sullivan, B.K.; Malone, J.H.; Schwalbe, C.R.

    2004-01-01

    Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

  8. Resilience Lost: Intersecting Land Use and Landscape Dynamics in the Prehistoric Southwestern United States

    Directory of Open Access Journals (Sweden)

    Steven Schmich

    2006-12-01

    Full Text Available The interdisciplinary framework known as resilience theory used by ecologists, social scientists, as well as policy makers, is primarily concerned with the sources of transformation and stability in complex socioecological systems. The laboratory of the long and diverse archaeological record is uniquely suited to testing some of the implications of this theoretical perspective. In this paper, we consider the history of land use and landscape change across the transition from foraging to agricultural subsistence economies in the Middle Chevelon Creek region of northern Arizona. Through this discussion, we highlight the potential roles of diversity and flexibility at multiple spatial and temporal scales in the resilience of human land use practices from the prehistoric past. Expressing the long-term history of this region in a more general theoretical language that bridges the social and natural sciences promotes the collaboration of scientists with expertise deriving from different traditional disciplines. Such a broad perspective is necessary to characterize changes and stabilities in complex socioecological systems.

  9. The Primary Factors Increasing Superintendent Tenure in the Urban Southwestern United States

    Science.gov (United States)

    Reynolds, Jason Wade

    2012-01-01

    It appears that superintendent turnover has become an accepted occurrence in districts across the country. Governing boards have resigned themselves to the idea that sustained district leadership is not realistic. There is a growing idea that good educational leaders, who are willing to endure the political landscape and the roller coaster ride…

  10. Identification of historic apple trees in the Southwestern United States and implications for conservation

    Science.gov (United States)

    The diversity of landrace and heirloom fruit varieties has declined worldwide over the past century. Abandoned farmsteads and historic orchards harbor considerable agrobiodiversity, but the extent and location of that diversity is poorly understood. We assessed the genetic diversity of 280 historic ...

  11. Taxonomic status of certain clapper rails of southwestern United States and northwestern Mexico

    Science.gov (United States)

    Banks, R.C.; Tomlinson, R.E.

    1974-01-01

    Examination of 58 Clapper Rail specimens taken in the breeding season from the Colorado Valley and the west coast of mainland Mexico verifies the distinctness of the races Rallus longirostris yomanensis, R. 1. rhizophorae, and R. 1. nayaritensis. Rallus 1. yumanensis is a relatively pale brown, pointed-winged, summer resident of freshwater marshes along the valley and delta of the Colorado River. Late winter specimens of yumanensis have been taken in freshwater and saltwater habitats in the Mexican states of Sinaloa and Puebla. Both R. 1. rhizophorae, a pale grayish bird, and R. 1. nayaritensis, a darker grayish form, are presumed year-round residents of the western Mexican mangrove swamps. Both have more rounded wings than yumanensis. The range of rhizophorae extends south along the coast from central Sonora to central Sinaloa, and that of nayaritensis from central Sinaloa to the vicinity of San Blas, Nayarit. Features of the range and characters of birds where the range of these two races approach each other are unclear.

  12. Meaningful traits for grouping plant species across arid ecosystems.

    Science.gov (United States)

    Bär Lamas, Marlene Ivonne; Carrera, A L; Bertiller, M B

    2016-05-01

    Grouping species may provide some degree of simplification to understand the ecological function of plants on key ecosystem processes. We asked whether groups of plant species based on morpho-chemical traits associated with plant persistence and stress/disturbance resistance reflect dominant plant growth forms in arid ecosystems. We selected twelve sites across an aridity gradient in northern Patagonia. At each site, we identified modal size plants of each dominant species and assessed specific leaf area (SLA), plant height, seed mass, N and soluble phenol concentration in green and senesced leaves at each plant. Plant species were grouped according with plant growth forms (perennial grasses, evergreen shrubs and deciduous shrubs) and plant morphological and/or chemical traits using cluster analysis. We calculated mean values of each plant trait for each species group and plant growth form. Plant growth forms significantly differed among them in most of the morpho-chemical traits. Evergreen shrubs were tall plants with the highest seed mass and soluble phenols in leaves, deciduous shrubs were also tall plants with high SLA and the highest N in leaves, and perennial grasses were short plants with high SLA and low concentration of N and soluble phenols in leaves. Grouping species by the combination of morpho-chemical traits yielded 4 groups in which species from one growth form prevailed. These species groups differed in soluble phenol concentration in senesced leaves and plant height. These traits were highly correlated. We concluded that (1) plant height is a relevant synthetic variable, (2) growth forms adequately summarize ecological strategies of species in arid ecosystems, and (3) the inclusion of plant morphological and chemical traits related to defenses against environmental stresses and herbivory enhanced the potential of species grouping, particularly within shrubby growth forms. PMID:26897637

  13. Influences of prior wildfires on vegetation response to subsequent fire in a reburned Southwestern landscape.

    Science.gov (United States)

    Coop, Jonathan D; Parks, Sean A; McClernan, Sarah R; Holsinger, Lisa M

    2016-03-01

    Large and severe wildfires have raised concerns about the future of forested landscapes in the southwestern United States, especially under repeated burning. In 2011, under extreme weather and drought conditions, the Las Conchas fire burned over several previous burns as well as forests not recently exposed to fire. Our purpose was to examine the influences of prior wildfires on plant community composition and structure, subsequent burn severity, and vegetation response. To assess these relationships, we used satellite-derived measures of burn severity and a nonmetric multidimensional scaling of pre- and post- Las Conchas field samples. Earlier burns were associated with shifts from forested sites to open savannas and meadows, oak scrub, and ruderal communities. These non-forested vegetation types exhibited both resistance to subsequent fire, measured by reduced burn severity, and resilience to reburning, measured by vegetation recovery relative to forests not exposed to recent prior fire. Previous shifts toward non-forested states were strongly reinforced by reburning. Ongoing losses of forests and their ecological values confirm the need for restoration interventions. However, given future wildfire and climate projections, there may also be opportunities presented by transformations toward fire-resistant and resilient vegetation types within portions of the landscape. PMID:27209778

  14. Structural diversity promotes productivity of mixed, uneven-aged forests in southwestern Germany.

    Science.gov (United States)

    Dănescu, Adrian; Albrecht, Axel T; Bauhus, Jürgen

    2016-10-01

    Forest diversity-productivity relationships have been intensively investigated in recent decades. However, few studies have considered the interplay between species and structural diversity in driving productivity. We analyzed these factors using data from 52 permanent plots in southwestern Germany with more than 53,000 repeated tree measurements. We used basal area increment as a proxy for productivity and hypothesized that: (1) structural diversity would increase tree and stand productivity, (2) diversity-productivity relationships would be weaker for species diversity than for structural diversity, and (3) species diversity would also indirectly impact stand productivity via changes in size structure. We measured diversity using distance-independent indices. We fitted separate linear mixed-effects models for fir, spruce and beech at the tree level, whereas at the stand level we pooled all available data. We tested our third hypothesis using structural equation modeling. Structural and species diversity acted as direct and independent drivers of stand productivity, with structural diversity being a slightly better predictor. Structural diversity, but not species diversity, had a significant, albeit asymmetric, effect on tree productivity. The functioning of structurally diverse, mixed forests is influenced by both structural and species diversity. These sources of trait diversity contribute to increased vertical stratification and crown plasticity, which in turn diminish competitive interferences and lead to more densely packed canopies per unit area. Our research highlights the positive effects of species diversity and structural diversity on forest productivity and ecosystem dynamics. PMID:27059713

  15. Assessment of historical surface-water quality data in southwestern Colorado, 1990-2005

    Science.gov (United States)

    Miller, Lisa D.; Schaffrath, Keelin R.; Linard, Joshua I.

    2013-01-01

    The spatial and temporal distribution of selected physical and chemical surface-water-quality characteristics were analyzed at stream sites throughout the Dolores and San Juan River Basins in southwestern Colorado using historical data collected from 1990 through 2005 by various local, State, Tribal, and Federal agencies. Overall, streams throughout the study area were well oxygenated. Values of pH generally were near neutral to slightly alkaline throughout most of the study area with the exception of the upper Animas River Basin near Silverton where acidic conditions existed at some sites because of hydrothermal alteration and(or) historical mining. The highest concentrations of dissolved aluminum, total recoverable iron, dissolved lead, and dissolved zinc were measured at sites located in the upper Animas River Basin. Thirty-two sites throughout the study area had at least one measured concentration of total mercury that exceeded the State chronic aquatic-life criterion of 0.01 μg/L. Concentrations of dissolved selenium at some sites exceeded the State chronic water-quality standard of 4.6 μg/L. Total ammonia, nitrate, nitrite, and total phosphorus concentrations generally were low throughout the study area. Overall, results from the trend analyses indicated improvement in water-quality conditions as a result of operation of the Paradox Valley Unit in the Dolores River Basin and irrigation and water-delivery system improvements made in the McElmo Creek Basin (Lower San Juan River Basin) and Mancos River Valley (Upper San Juan River Basin).

  16. Petrography and geochronology of the Sao Jose dos Quatro Marcos granitoids, southwestern Mato Grosso, Brazil

    International Nuclear Information System (INIS)

    An area of about 400Km2 was mapped in the region of Sao Jose dos Quatro Marcos, southwestern State of Mato Grosso, western Brazil. Various granitoid rocks were recognized, intrusive into basement gneisses, and mapped as two distinct units, one of massive late granitoids (mostly 3a and 3b granites) and one of foliated granitoids, with oriented mafic minerals, consisting mainly of tonalites and, to a lesser degree, of granodiorites. The sequence of intrusion is from tonalites to granodiorites to late granites. Magmatic textures are usually preserved in the rocks, with the exception of some clearly recrystallized samples. Field aspects, as well as petrography and mineralogy, suggest a genetic relationship between the various granitoid types, showing overall features commonly cited as typical of 'I' lineages. A Rb/Sr whole-rock isochron obtained from 3b granites (six points) shows an age of 1,472 +- 19 Ma, and Sr8786 initial ratio of 0.7037 +- 0.0004; a nine point isochron (adding two tonalites and one granodiorite) yelds similar results (age of 1,505 +- 20 Ma, initial ratio of 0.7029+- 0.0003). The obtained ages confirm the existence of a thermal-magmatic event at about 1,500 Ma at the southern border of the Amazon Craton. (author)

  17. Semi-arid development: competitiveness factors in biodiesel productive chain

    Directory of Open Access Journals (Sweden)

    Breno Barros Telles do Carmo

    2009-04-01

    Full Text Available The new global market competitiveness considerer the competition between productive chains (PC or supply chains, not just between enterprises. In this case, it can be observed collaboration and cooperation enterprises that dispute with others productives chain. The PC competitiveness can be impaired if is subject by inhibitors factors, that can impairer the performance. This paper analyses these competitiveness factors inhibitors in biodiesel productive chain (CPB in semi-arid area: exported product, market knowledge, competitiveness position, opportunities to aggregate value in chain, cooperation between enterprises, enterprises way of thinking and paternalism by government. It was done this analyses to compare CPB with the world.

  18. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia

    DEFF Research Database (Denmark)

    Costa, A.; Madeira, M.; Lima Santos, J.;

    2014-01-01

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands in re...... patterns of oak recruitment and therefore, its study may be helpful in highlighting future baselines for the sustainable management of oak woodlands....... in relation to their surrounding landscape matrix, and to characterize and quantify woodland boundaries and edges. The present study aims to fill this gap by analyzing fragmentation patterns of oak woodlands over a 50-year period (1958-2007) in three landscapes. Using archived aerial imagery from 1958, 1995...... by shrubland and by new afforestation areas in the oak woodland landscape surrounding matrix, led to the highest values for edge contrast length trends of 5.0 and 12.3, respectively. Linear discriminant analysis was performed to delineate fragmented woodland structures and identify metric variables...

  19. Macrofungi in the lateritic scrub jungles of southwestern India

    Directory of Open Access Journals (Sweden)

    A. A. Greeshma

    2015-09-01

    Full Text Available A pilot study on macrofungi in scrub jungles (with and without fire-impact in lateritic region of southwestern coast of India was carried out.  Out of 11 species in 10 genera recovered, six and five species were confined to scrub jungle and fire-impacted scrub jungle, respectively.  An ectomycorrhizal Amanita sp. was the most frequent in scrub jungle associated with exotic (Acacia auriculiformis and A. mangium and plantation (Anacardium occidentale trees.  Based on traditional knowledge, it is a highly edible and nutritional delicacy in the coastal regions.  Astraeus odoratus was another common ectomycorrhizal fungus in native trees Hopea ponga, which was recovered from the fire-impacted scrub jungle and is possibly edible.  Edible termite mound mushroom Termitomyces striatus was also common in the fire-impacted scrub jungle.  Chlorophyllum molybdites was the most frequent mushroom in the fire-impacted scrub jungle.  

  20. Formal dementia care among first nations in southwestern Ontario.

    Science.gov (United States)

    Finkelstein, Sara A; Forbes, Dorothy A; Richmond, Chantelle A M

    2012-09-01

    This article explores how dementia care is provided to First Nations communities in southwestern Ontario. Data were collected through in-depth interviews with health care providers and analysed using a constructivist grounded-theory methodology. Two interrelated frameworks for understanding dementia care were identified: a care delivery framework and a knowledge framework. The care delivery framework identified care goals, care elements being provided, care barriers, and strategies and solutions to deliver care and overcome barriers. The knowledge framework defined four groups of knowledge stakeholders: persons with dementia, informal care providers, formal care providers, and the First Nations community. It identified the knowledge each stakeholder held or needed and processes of sharing - or failing to share - knowledge in dementia care. Several barriers, many created by a lack of knowledge, negatively impacted dementia care. However, health care professionals had effective strategies for providing care, designed to overcome barriers and which encompassed elements of knowledge sharing. PMID:22828489

  1. Deep resistivity structure in southwestern Utah and its geothermal significance

    Energy Technology Data Exchange (ETDEWEB)

    Wannamaker, P.E.; Ward, S.H.; Hohmann, G.W.; Sill, W.R.

    1983-02-01

    Magnetotelluric (MT) measurements in southwestern Utah have yielded a model of resistivity structure in this area to a depth of about 100 km. The MT observations are strongly affected by Great Basin graben sedimentary fill, which constitutes conductive upper-crustal lateral inhomogeneity and requires simulation using two- and three-dimensional modeling algorithms before deeper portions of the resistivity section can be resolved. Included in the model is a layer of low resistivity (20 ..cap omega..-m) residing from 35 to 65 km depth. Sensitivity tests of the data to the structure weigh strongly against the top of this layer being as shallow as 25 km and against the conductivity and thickness of the layer being highly correlated. No intra-crustal low-resistivity layer is indicated by the MT data.

  2. Tectonic evolution of the Tombel graben basement, southwestern Cameroon

    Institute of Scientific and Technical Information of China (English)

    M.S.Njome; C.E.Suh

    2005-01-01

    Planar structures (foliations and fractures) around the Tombel graben (southwestern end of the Central African Shear zone system) have been investigated and analyzed with the aim of unraveling the tectonic evolution of the basement. The foliations show two major trends, an older N-S-trending gneissose layering of uncertain agereworked by a later Pan-African (600 + 50 Ma) NE-SW ductile trend that is contemporaneous with sinistral shearing and mylonitization. The brittle phase characterized by NW-SE-trending open and partially filled fractures is younger than the mylonitization event and although it has not been dated, it is suggested that the origin of these fractures is linked to the onset of volcanism along the Cameroon volcanic line-31 m.y. ago.The mylonitic foliation is recognized for the first time and supports a tectonic evolution model for the Tombel graben in which ductile non-coaxial deformation was succeeded by brittle failure.

  3. Using Canonical Correlation Analysis to Identify Environmental Attitude Groups: Considerations for National Forest Planning in the Southwestern U.S.

    Science.gov (United States)

    Prera, Alejandro J.; Grimsrud, Kristine M.; Thacher, Jennifer A.; McCollum, Dan W.; Berrens, Robert P.

    2014-10-01

    As public land management agencies pursue region-specific resource management plans, with meaningful consideration of public attitudes and values, there is a need to characterize the complex mix of environmental attitudes in a diverse population. The contribution of this investigation is to make use of a unique household, mail/internet survey data set collected in 2007 in the Southwestern United States (Region 3 of the U.S. Forest Service). With over 5,800 survey responses to a set of 25 Public Land Value statements, canonical correlation analysis is able to identify 7 statistically distinct environmental attitudinal groups. We also examine the effect of expected changes in regional demographics on overall environmental attitudes, which may help guide in the development of socially acceptable long-term forest management policies. Results show significant support for conservationist management policies and passive environmental values, as well as a greater role for stakeholder groups in generating consensus for current and future forest management policies.

  4. Tropical Cyclogenesis Conditions in the South-Western Indian Ocean

    Science.gov (United States)

    Meetoo, Cherina; Roux, Frank

    2013-04-01

    Mature tropical cyclones around the world exist through similar atmospheric and oceanic processes: the necessary conditions for these storms to occur (warm SST, atmospheric instability, high humidity in the low to mid-troposphere, low wind shear, enough Coriolis force) are identical over all basins. However, the environments within which pre-existing disturbances evolve into warm-core cyclonic circulations are fairly different in the various basins. This is partly due to the influence of large-scale climatic cycles (e.g. ENSO, AMO, IOD, etc.) and of synoptic-scale propagating modes (e.g. tropical waves, Madden-Julian Oscillation, etc.). While many studies have examined the specific situations of the tropical basins in the northern hemisphere, storm formation is much less known in the southern hemisphere. Concerning the south-western Indian Ocean (0-30°S, 50-100°E), Bessafi and Wheeler (2006) have shown a large and statistically significant modulation by MJO and convectively coupled Equatorial Rossby waves, and a small yet significant modulation by Kelvin waves. The present study concerns the analysis of cyclogenetic evolution of named storms in the south-western Indian Ocean during 13 seasons from 1999-2000 to 2011-2012, from ECMWF ERA-Interim reanalyses and Meteosat-7 images. First, the methods used to find tropical storms (also identified in the IBTrACS database) in the ERA-Interim reanalyses will be shown. Besides, the upper- and lower-troposphere conditions in which storms develop will be examined using integrated diagnoses (McTaggart-Cowan et al., 2008). A spectral analysis in space and time of the different dynamical and thermodynamical environmental parameters (from ERA-Interim reanalyses and Meteosat-7 images) will then be presented. This analysis shows slow (period > 10 days) and fast (period < 10 days) eastward and westward tropical waves. Finally, the relationship between these waves and developing and non-developing storm cases will be discussed.

  5. Canopy Profiling for Vegetation Mapping in South-Western Australian Forested Ecosystems

    Science.gov (United States)

    Schut, A. G. T.; Wardell-Johnson, G. W.; Baran, I.

    2012-09-01

    Anthropogenic climate change is already impacting native vegetation world-wide. Thus accurate mapping of current vegetation condition is necessary for benchmarking and conservation planning. We examine the potential for the mapping of native vegetation of forested ecosystems in south-western Australia using LiDAR data. Airborne LiDAR (distance between data points 1.2 m) and RGB imagery was acquired with a discrete 4-return Leica ALS 50-II system in April 2011 and vertical canopy profiles determined in Boyagin Nature Reserve. Elevation, slope and geomorphological descriptions of the terrain in combination with vertical canopy profiles based on presence/absence of returns within voxels were derived from the LiDAR data and processed at a spatial resolution of 4.0 meters. Based on these profiles, crown height and depth, ground cover, mean intensity of crown returns, presence of understory and number of vegetation layers were determined for each grid cell. Unsupervised classification revealed distinctive canopy profiles. Vegetation is strongly linked to geomorphology in this old landscape. Thus Kwongan shrubland occurs on the plateaus, Allocasuarina heugeliana woodland on the fringes of rock outcrops, Eucalyptus astringens and E. accedens woodland on breakaways and E. wandoo and Corymbia calophylla woodland in more fertile valley systems. The vegetation types present within distinctive spatial clusters were determined in two field visits. Vegetation types were mapped with an object-based image analysis approach at geomorphological, vegetation and tree scales using the geomorphology of the terrain and structural, textural and reflective characteristics of the canopy. All vertical profiles identified were present on each geomorphological unit. Tree species with a distinctive vertical profile such as Eucalyptus astringens and Allocasuarina heugeliana were defined and distinguished in combination with object-based geomorphological and spatial characteristics. Vegetation

  6. Aerosol radiative effects over global arid and semi-arid regions based on MODIS Deep Blue satellite observations

    Science.gov (United States)

    Hatzianastassiou, Nikolaos; Papadimas, Christos D.; Gkikas, Antonis; Matsoukas, Christos; Sayer, Andrew M.; Hsu, N. Christina; Vardavas, Ilias

    2014-05-01

    Aerosols are a key parameter for several atmospheric processes related to weather and climate of our planet. Specifically, the aerosol impact on Earth's climate is exerted and quantified through their radiative effects, which are induced by their direct, indirect and semi-direct interactions with radiation, in particular at short wavelengths (solar). It is acknowledged that the uncertainty of present and future climate assessments is mainly associated with aerosols and that a better understanding of their physico-chemical, optical and radiative effects is needed. The contribution of satellites to this aim is important as a complementary tool to climate and radiative transfer models, as well as to surface measurements, since space observations of aerosol properties offer an extended spatial coverage. However, such satellite based aerosol properties and associated model radiation computations have suffered from unavailability over highly reflecting surfaces, namely polar and desert areas. This is also the case for MODIS which, onboard the Terra and Aqua satellites, has been providing high quality aerosol data since 2000 and 2002, respectively. These data, more specifically the aerosol optical depth (AOD) which is the most important optical property used in radiative and climate models, are considered to be of best quality. In order to address this problem, the MODIS Deep Blue (DB) algorithm has been developed which enables the retrieval of AOD above arid and semi-arid areas of the globe, including the major deserts. In the present study we make use of the FORTH detailed spectral radiative transfer model (RTM) with MODIS DB AOD data, supplemented with single scattering albedo (SSA) and asymmetry parameter (AP) aerosol data from the Global Aerosol DataSet (GADS) to estimate the aerosol DREs over the arid and semi-arid regions of the globe. The RTM is run using surface and atmospheric data from the ISCCP-D2 dataset and the NCEP global reanalysis project and computes the

  7. Is aridity a high-order control on the hydro-geomorphic response of burned landscapes?

    Science.gov (United States)

    Sheridan, Gary; Van der Sant, Rene; Nyman, Petter; Lane, Patrick

    2015-04-01

    Fire results in hydro-geomorphic changes that are spatially variable and difficult to predict. In this study we compile 294 infiltration measurements, ten other soil, catchment runoff and erosion datasets, and a year of new data from 15 natural runoff plots across an aridity gradient from the eastern Victorian uplands in SE Australia. The results show that aridity (a function of the long term mean precipitation and net radiation) is associated with low post-fire infiltration capacities, increasing the chance of surface runoff, and strongly increasing the chance of debris flows. Runoff plots from the wettest site (aridity = 1.1) had an average runoff ratio of 0.3% compared with 33.6% for the most arid sites (aridity = 2.4). Post-fire debris flows were only observed in the more arid locations within the Victorian uplands, and resulted in erosion rates more than two orders of magnitude greater than non-debris flow processes. We therefore argue that in south eastern Australia aridity is a high-order control on the magnitude of post-wildfire hydro-geomorphic processes. The results from this Australian study may also help to provide insight into the landscape controls on post fire debris flows elsewhere. Aridity is a landscape-scale parameter that is mappable at a high resolution and therefore is a useful predictor of the spatial variability of the magnitude of post-fire hydro-geomorphic responses.

  8. A methodology to assess and evaluate rainwater harvesting techniques in (semi-) arid regions

    NARCIS (Netherlands)

    Adham, Ammar; Riksen, Michel; Ouessar, Mohamed; Ritsema, Coen J.

    2016-01-01

    Arid and semi-arid regions around the world face water scarcity problems due to lack of precipitation and unpredictable rainfall patterns. For thousands of years, rainwater harvesting (RWH) techniques have been applied to cope with water scarcity. Researchers have used many different methodologie

  9. Conservation tillage of rainfed maize in semi-arid Zimbabwe: A review

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.

    2015-01-01

    Food security in Sub-Saharan Africa, particularly in semi-arid tropics (41% of the region; 6 months of dry season) is threatened by droughts, dry spells and infertile soils. In Zimbabwe, 74% of smallholder farming areas are located in semi-arid areas mostly in areas with soils of low fertility and w

  10. An overview of biodegradation of LNAPLs in coastal (semi)-arid environment

    NARCIS (Netherlands)

    Yadav, B.K.; Hassanizadeh, S.M.

    2011-01-01

    Contamination of soil and water due to the release of light non-aqueous phase liquids (LNAPLs) is a ubiquitous problem. The problem is more severe in arid and semi-arid coastal regions where most of the petroleum production and related refinery industries are located. Biological treatment of these o

  11. Analysis and evaluation of tillage on an alfisol ina semi-arid tropical region of India

    NARCIS (Netherlands)

    Klaij, M.C.

    1983-01-01

    Tillage field experiments were conducted on Alfisols in a semi-arid tropical environment in India. The research was conducted within the framework of the Farming Systems Research Program of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).To put the experiments into per

  12. Impact of grazing on range plant community components under arid Mediterranean climate in northern Syria

    NARCIS (Netherlands)

    Niane, A.A.

    2013-01-01

    Keywords: Rotational grazing, full protection, continuous grazing species richness, species diversity, soil seed bank, Bayesian methods, Salsola vermiculata, seed longevity, rangeland management, Syria.   Rangelands represent 70% of the semi-arid and arid Mediterranean land mass. It is a n

  13. Differences in the ARID-1 alpha expressions in squamous and adenosquamous carcinomas of uterine cervix.

    Science.gov (United States)

    Solakoglu Kahraman, Dudu; Diniz, Gulden; Sayhan, Sevil; Ayaz, Duygu; Uncel, Melek; Karadeniz, Tugba; Akman, Tulay; Ozdemir, Aykut

    2015-10-01

    AT-rich interactive domain 1A (ARID1A) is a tumor suppressor gene involved in chromatin remodeling which encodes ARID1A (BAF250a) protein. Recent studies have shown the loss of ARID1A expression in several types of tumors. This retrospective study was designed to evaluate the differences in tissue expressions of ARID1A in a spectrum of cervical neoplasms. Cervical intraepithelial neoplasms, invasive squamous or adenosquamous carcinomas were identified in 100 patients recently diagnosed as cervical neoplasms based on pathology databases. In this series, there were 29 low- and 29 high-grade cervical intraepithelial neoplasms, 27 squamous cell carcinomas, and 15 adenosquamous carcinomas. Mean age of the patients was 47.8 ± 13 years (20-80 years). It was determined that the expression of ARID1A was statistically significantly down-regulated in adenosquamous carcinomas when compared with non-invasive or invasive squamous cell carcinomas (p = 0.015). Lower levels of the ARID1A expression were detected in cases with adenosquamous carcinomas (60%), low- or high-grade squamous intraepithelial lesion (SIL) (31%), and squamous cell carcinomas (18.5%). Our findings have demonstrated the presence of a correlation between ARID1A expression and adenomatous differentiation of uterine squamous cell carcinomas. Therefore, ARID1A gene may suggestively have a role in the pathogenesis of cervical adenosquamous carcinomas.

  14. Expansive Soil Properties in a Semi-Arid Region

    Directory of Open Access Journals (Sweden)

    MuawiaA. Dafalla

    2012-11-01

    Full Text Available The expansive soils in semi-arid regions are of great concern to design and geotechnical engineers. Range and variations of geotechnical properties of soils are very useful for appropriate design. Saudi Arabia; a semi arid region attracted the attention of researchers and practicing engineers over the last three decades following the rapid urbanizations in different parts of the country. Advanced testing equipments were made available for this study. The research group conducted joint visits with high officials from different municipality authorities to survey the problem and study the extent of damage to various structures. The areas visited included Al Ghatt, Al Zulfi, Al Hofuf, Um Al Sahik, Al Qatif, Tabuk, Tayma and Al Qaleeba. Single and two storey buildings, boundary walls, pavements and asphalt roads suffered significant damage in many parts of the visited locations. This paper presents the outcome of survey and a general review of previous works carried out for swelling clays in Saudi Arabia. Engineering properties for typical soil formation are presented.

  15. Feasibility of groundwater recharge dam projects in arid environments

    Science.gov (United States)

    Jaafar, H. H.

    2014-05-01

    A new method for determining feasibility and prioritizing investments for agricultural and domestic recharge dams in arid regions is developed and presented. The method is based on identifying the factors affecting the decision making process and evaluating these factors, followed by determining the indices in a GIS-aided environment. Evaluated parameters include results from field surveys and site visits, land cover and soils data, precipitation data, runoff data and modeling, number of beneficiaries, domestic irrigation demand, reservoir objectives, demography, reservoirs yield and reliability, dam structures, construction costs, and operation and maintenance costs. Results of a case study on more than eighty proposed dams indicate that assessment of reliability, annualized cost/demand satisfied and yield is crucial prior to investment decision making in arid areas. Irrigation demand is the major influencing parameter on yield and reliability of recharge dams, even when only 3 months of the demand were included. Reliability of the proposed reservoirs as related to their standardized size and net inflow was found to increase with increasing yield. High priority dams were less than 4% of the total, and less priority dams amounted to 23%, with the remaining found to be not feasible. The results of this methodology and its application has proved effective in guiding stakeholders for defining most favorable sites for preliminary and detailed design studies and commissioning.

  16. Aridity, desalination plants and tourism in the eastern Canary Islands

    Directory of Open Access Journals (Sweden)

    José-León García-Rodríguez

    2016-05-01

    Full Text Available The islands of Lanzarote and Fuerteventura are the easternmost of the Canary Islands, and are located on the southern edge of the temperate zone, in the subtropical anticyclone belt. With less than 150 mm of rainfall a year, they are classified as an arid zone. Their inhabitants have devised original agricultural systems to combat the aridity, although low yields have historically limited socio-economic development and population growth. These systems were used until the introduction of seawater desalination plants and the arrival of tourism in the last third of the twentieth century, which improved living standards for the local population but also led to a cultural transition. Nevertheless, these farming systems have left behind an important regional heritage, with an environmental and scenic value that has played an integral role in the latest phase of development. The systems have become a tourist attraction and have been central to the two islands being designated biosphere reserves by UNESCO. This article aims to analyse the main socioeconomic and land-use changes that have come about as a result of desalination technology.

  17. Microclimates of the arid lands ecology reserve, 1968--1975

    Energy Technology Data Exchange (ETDEWEB)

    Thorp, J. M.; Hinds, W. T.

    1977-04-01

    The climatology of the Hanford Reservation Arid Lands Ecology (ALE) Reserve does not end, of course, with this report. As this goes to press the arid lands of eastern Washington are experiencing the driest winter in 65 years of record. Even without including this winter's (1976-77) data in our summaries here, we have been fortunate to have had a very dry winter (1972-73) and a very wet winter (1973-74) occur within our first 8 years of climatological measurements on the Reserve. Our primary purpose with this report has been to analyze the first 8 years of climatological measurements from the ALE Reserve and to identify persistent spatial variations between stations or groups of stations. From these variations we have been able to recognize several distinct, but related microclimates occurring within the Reserve. Secondly, we have shown that significant correlations exist between each microclimate on the Reserve and that of the Hanford Meteorological Station nearby. These correlations, coupled with the 30-year weather record at the HMS and possibly with the 32-year (1912-1944) record at the Hanford townsite, allow ALE Reserve temperature and precipitation estimates to be made for years prior to the ALE climatology program.

  18. Glacial aridity in central Indonesia coeval with intensified monsoon circulation

    Science.gov (United States)

    Konecky, Bronwen; Russell, James; Bijaksana, Satria

    2016-03-01

    The Last Glacial Maximum was cool and dry over the Indo-Pacific Warm Pool (IPWP), a key region driving global oceanic-atmospheric circulation. Both low- and high-latitude teleconnections with insolation, ice sheets, and sea level have been suggested to explain the pervasive aridity observed in paleoecological and geomorphic data. However, proxies tracking the H- and O-isotopic composition of rainfall (e.g., speleothems, sedimentary biomarkers) suggest muted aridity or even wetter conditions than the present, complicating interpretations of glacial IPWP climate. Here we use multiproxy reconstructions from lake sediments and modern rainfall isotopic measurements from central Indonesia to show that, contrary to the classical "amount effect," intensified Australian-Indonesian monsoon circulation drove lighter H- and O-isotopic composition of IPWP rainfall during the LGM, while at the same time, dry conditions prevailed. Precipitation isotopes are particularly sensitive to the apparent increase in monsoon circulation and perhaps also decreased moisture residence time implied by our data, explaining contrasts among proxy records while illuminating glacial IPWP atmospheric circulation, a key target for climate models.

  19. An Evaluation of Unsaturated Flow Models in an Arid Climate

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, J.

    1999-12-01

    The objective of this study was to evaluate the effectiveness of two unsaturated flow models in arid regions. The area selected for the study was the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site in Nye County, Nevada. The two models selected for this evaluation were HYDRUS-1D [Simunek et al., 1998] and the SHAW model [Flerchinger and Saxton, 1989]. Approximately 5 years of soil-water and atmospheric data collected from an instrumented weighing lysimeter site near the RWMS were used for building the models with actual initial and boundary conditions representative of the site. Physical processes affecting the site and model performance were explored. Model performance was based on a detailed sensitivity analysis and ultimately on storage comparisons. During the process of developing descriptive model input, procedures for converting hydraulic parameters for each model were explored. In addition, the compilation of atmospheric data collected at the site became a useful tool for developing predictive functions for future studies. The final model results were used to evaluate the capacities of the HYDRUS and SHAW models for predicting soil-moisture movement and variable surface phenomena for bare soil conditions in the arid vadose zone. The development of calibrated models along with the atmospheric and soil data collected at the site provide useful information for predicting future site performance at the RWMS.

  20. Sustainable Small-Scale Agriculture in Semi-Arid Environments

    Directory of Open Access Journals (Sweden)

    Scott Ingram

    2011-03-01

    Full Text Available For at least the past 8000 years, small-scale farmers in semi-arid environments have had to mitigate shortfalls in crop production due to variation in precipitation and stream flow. To reduce their vulnerability to a shortfall in their food supply, small-scale farmers developed short-term strategies, including storage and community-scale sharing, to mitigate inter-annual variation in crop production, and long-term strategies, such as migration, to mitigate the effects of sustained droughts. We use the archaeological and paleoclimatic records from A.D. 900-1600 in two regions of the American Southwest to explore the nature of variation in the availability of water for crops, and the strategies that enhanced the resilience of prehistoric agricultural production to climatic variation. Drawing on information concerning contemporary small-scale farming in semi-arid environments, we then suggest that the risk coping and mitigation strategies that have endured for millennia are relevant to enhancing the resilience of contemporary farmers' livelihoods to environmental and economic perturbations.

  1. Soil microbial responses to nitrogen addition in arid ecosystems

    Directory of Open Access Journals (Sweden)

    Robert L Sinsabaugh

    2015-08-01

    Full Text Available The N cycle of arid ecosystems is influenced by low soil organic matter, high soil pH and extremes in water potential and temperature that lead to open canopies and development of biological soil crusts (biocrusts. We investigated the effects of N amendment on soil microbial dynamics in a Larrea tridentata-Ambrosia dumosa shrubland site in southern Nevada USA. Sites were fertilized with a NO3-NH4 mix at 0, 7, and 15 kg ha-1 yr-1 from March 2012 to March 2013. In March 2013, biocrust (0-0.5 cm and bulk soils (0-10 cm were collected beneath Ambrosia canopies and in the interspaces between plants. Biomass responses were assessed as bacterial and fungal SSU rRNA gene copy number and chlorophyll a concentration. Metabolic responses were measured by five ecoenzyme activities (EEA and rates of N transformation. By most measures, nutrient availability, microbial biomass and process rates were greater in soils beneath the shrub canopy compared to the interspace between plants, and greater in the surface biocrust horizon compared to the deeper 10 cm soil profile. Most measures responded positively to experimental N addition. Effect sizes were generally greater for bulk soil than biocrust. Results were incorporated into a meta-analysis of arid ecosystem responses to N.

  2. Resistance Status of the Malaria Vector Mosquitoes, Anopheles stephensi and Anopheles subpictus Towards Adulticides and Larvicides in Arid and Semi-Arid Areas of India

    OpenAIRE

    Tikar, S. N.; M J Mendki; Sharma, A K; D. Sukumaran; Veer, Vijay; Prakash, Shri; Parashar, B. D.

    2011-01-01

    Susceptibility studies of malaria vectors Anopheles stephensi Liston (Diptera: Culicidae) and An. subpictus Grassi collected during 2004–2007 from various locations of Arid and Semi-Arid Zone of India were conducted by adulticide bioassay of DDT, malathion, deltamethrin and larvicide bioassay of fenthion, temephos, chlorpyriphos and malathion using diagnostic doses. Both species from all locations exhibited variable resistance to DDT and malathion from majority of location. Adults of both the...

  3. Climate change and plant community composition in national parks of the southwestern US: forecasting regional, long-term effects to meet management needs

    Science.gov (United States)

    Munson, Seth M.; Belnap, Jayne; Webb, Robert H.; Hubbard, J. Andrew; Reiser, M. Hildegard; Gallo, Kirsten

    2014-01-01

    The National Park Service (NPS) faces tremendous management challenges in the future as climates alter the abundance and distribution of plant species. These challenges will be especially daunting in the southwestern U.S., where large increases in aridity are forecasted. The expected reduction in water availability will negatively affect plant growth and may result in shifts of plant community composition. Synthesis of climate and plant vital sign data from National Park Service Inventory and Monitoring (I&M) networks is essential to provide park managers with important insights into contemporary climate responses and a sound basis to forecast likely future changes at species, community, and ecosystem scales. We describe a collaboration between the U.S. Geological Survey (USGS) and NPS in which we have conducted regional cross-site assessments across the Sonoran and Chihuahuan Deserts to understand plant species responses to past climate and forecast future plant community composition. We also determined whether a widely-implemented vegetation monitoring protocol in these deserts is suitable to track long-term vegetation changes caused by climate and other factors. Our results from these analyses are intended to help natural resource managers identify and prepare for changes in plant cover and community composition and evaluate the efficacy of current monitoring programs.

  4. Preliminary results of high resolution magneto-biostratigraphy of continental sequences in Chapala Basin, Southwestern Mexico

    Science.gov (United States)

    Mendez Cardenas, D. L.; Benammi, M.

    2007-05-01

    Chapala Lake is south from Guadalajara, Jalisco State (Southwestern Mexico). Belongs to a series of Pliocenic lakes along the Mexican Volcanic Belt. It is localized in the Chapala rift, and the entire area is controlled by the tectonic setting of the Colima, Tepic and Chapala rifts, constituting the triple junction rift-rift-rift. The deposits studied belong to volcanosedimentary sequences, composed by lacustrine and fluvial associations alternated with units of ash and pumice. The faunistic component reported consists at least of 27 mammals species, and the sediments were there're in have to work with special attention for seek rodents by handpicking. Probably these rodents will be the clue to determine the deposits correlation. Core demagnetization shows that they are low-coercivity magnetic minerals like magnetite or Ti-magnetite. It was verified that the characteristic magnetization corresponds to MNRp and the inversion test resulted good. Rodents are represented by Geomynae, Sigmondontinae and Sciurinae. The Geomynae family is the most common, and the faunistic association indicates Blancan age. This also allows a correlation with the polarity pattern in the GSS between 3,6 and 2,6 Ma. Actually, is known that this kind of studies in continental sequences supported with paleontological record of vertebrates could give us a more precised calibration of the age of such deposits. Allowing better understanding of the evolution of these mammals and their path trough geological record. This work shows the preliminary results of rodents palaeontology and high resolution magneto-stratigraphy in the units from to Chapala Basin.

  5. Late Pleistocene lithostratigraphy and sequences in the southwestern Mesopotamia (Argentina): Evidences of the last interglacial stage

    Science.gov (United States)

    Ernesto, Brunetto; Soledad, Ferrero Brenda; Ignacio, Noriega Jorge

    2015-03-01

    The aim of this paper is to show the stratigraphic record of the Late Pleistocene corresponding to the distal region of the Paraná River basin. It displays sedimentological, paleontological and geochronological evidences that characterise the last interglacial-glacial cycle. In particular, strong environmental records are shown for the Last Interglacial Stage (LIS). Salto Ander Egg Formation (SAEF) is defined as a new lithostratigraphic unit representative of the Late Pleistocene in southwestern Mesopotamia. This unit is formed of complex fluvial deposits, which contains a heterogeneous collection of sub-environments, of ages ranging from 120 to 60 ky BP. The clast-supported gravel facies containing sparse boulders indicate high flow during a humid climate. The large and middle-scale architectures of fluvial sedimentary bodies evidence the relationship between the sediment accommodation and the sea level oscillations. Three sub-sequences identified in the succession suggest a transgressive trend during the MIS5e, a highstand stage in MIS5c, and a minor transgressive cycle during MIS3. A Brazilian faunal association collected at the bottom of the sequence and sedimentological interpretations display wet and warm climatic conditions, typical of tropical or subtropical environments. Such environmental conditions are characteristic of the maximum of the last interglacial stage (MIS5e) and show a signal stronger than the signal of the current interglacial stage. All these data show a direct correlation between the increases of paleodischarges and the elevation of the sea level. The whole sequence is completed with transitional swampy deposits, accumulated probably during the MIS3/MIS2 transition, and the typical loess of the Tezanos Pinto Formation, mantled during the Last Maximum Glacial.

  6. Impact of rhizobial populations and their host legumes on microbial activity in soils of arid regions in Tunisia

    International Nuclear Information System (INIS)

    Nitrogen fixing legumes and their microsymbionts are a fundamental contributor to soil fertility and prevent their degradation in arid and semi arid ecosystems. In Tunisia, few data are available on the contribution of these legumes in microbial activity in the arid soil. In this objective, a study was undertaken on five leguminous species from different arid regions to evaluate their ability to regenerate microbiological processes of the soil: Genista saharea, Genista microcephala, Acacia tortilis sspr raddiana, Retama raetam and Prosopis stephaniana. (Author)

  7. Impact of rhizobial populations and their host legumes on microbial activity in soils of arid regions in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Fterich, A.; Mahdhi, M.; Mars, M.

    2009-07-01

    Nitrogen fixing legumes and their microsymbionts are a fundamental contributor to soil fertility and prevent their degradation in arid and semi arid ecosystems. In Tunisia, few data are available on the contribution of these legumes in microbial activity in the arid soil. In this objective, a study was undertaken on five leguminous species from different arid regions to evaluate their ability to regenerate microbiological processes of the soil: Genista saharea, Genista microcephala, Acacia tortilis sspr raddiana, Retama raetam and Prosopis stephaniana. (Author)

  8. Salinity tolerance and mycorrhizal responsiveness of native xeroriparian plants in semi-arid western USA

    Science.gov (United States)

    Beauchamp, Vanessa B.; Walz, C.; Shafroth, P.B.

    2009-01-01

    Restoration of salt-affected soils is a global concern. In the western United States, restoration of salinized land, particularly in river valleys, often involves control of Tamarix, an introduced species with high salinity tolerance. Revegetation of hydrologically disconnected floodplains and terraces after Tamarix removal is often difficult because of limited knowledge regarding the salinity tolerance of candidate native species for revegetation. Additionally, Tamarix appears to be non-mycorrhizal. Extended occupation of Tamarix may deplete arbuscular mycorrhizal fungi in the soil, further decreasing the success of revegetation efforts. To address these issues, we screened 42 species, races, or ecotypes native to southwestern U.S. for salinity tolerance and mycorrhizal responsiveness. As expected, the taxa tested showed a wide range of responses to salinity and mycorrhizal fungi. This variation also occurred between ecotypes or races of the same species, indicating that seed collected from high-salinity reference systems is likely better adapted to harsh conditions than seed originating from less saline environments. All species tested had a positive or neutral response to mycorrhizal inoculation. We found no clear evidence that mycorrhizae increased salinity tolerance, but some species were so dependent on mycorrhizal fungi that they grew poorly at all salinity levels in pasteurized soil. ?? 2009 Elsevier B.V.

  9. Contaminants in Southwestern Willow Flycatcher Eggs and Prey Items, Arizona, 1998-2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study documented concentrations and potential effects of organochlorine compounds and metals in addled eggs and potential prey of the endangered southwestern...

  10. Characteristics and distributions of atmospheric mercury emitted from anthropogenic sources in Guiyang, southwestern China

    Science.gov (United States)

    Continuous measurements of speciated atmospheric mercury (Hg), including gaseous elemental mercury (GEM), particulate mercury (PHg), and reactive gaseous mercury (RGM) were conducted in Guizhou Province, southwestern China. Guiyang Power Plant (GPP), Guiyang Wujiang Cement Plant,...

  11. Lissotriton vulgaris paedomorphs in south-western Romania: a consequence of a human modified habitat?

    Directory of Open Access Journals (Sweden)

    Severus D. Covaciu-Marcov

    2011-06-01

    Full Text Available A Lissotriton vulgaris paedomorph population was identified for the first time ever in south-western Romania. The newts inhabiting a permanent but artificial habitat, surrounded by agricultural fields.

  12. Aeolian deposition of Arabia and Somalia sediments on the southwestern continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.

    Kaolinite, smectite, illite and chlorite as major clay minerals and palygorskite and gibbsite in minor quantities have been recorded from the slope of southwestern continental margin of India. Contribution of kaolinite, smectite and gibbsite is from...

  13. 1:75K-Scale Geologic Mapping of Southwestern Melas Chasma, Mars

    Science.gov (United States)

    Edgar, L. A.; Skinner, J. A.

    2016-06-01

    The goal of this work is to document the geologic evolution of southwestern Melas Chasma, and to place localized observations into a broader, standardized context for comparison to other similar regions within the Valles Marineris basin system.

  14. Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region.

    Science.gov (United States)

    Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

    2015-01-01

    Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including "Public desalinated distribution system", "PET Bottled Drinking Water", "Private desalinated water suppliers" and "Household desalinated water units" were assessed based on criteria and sub-criteria. Data were aggregated and normalized to apply Performance Ratings of Alternatives. Also, the Performance Ratings of Alternatives were aggregated again to achieve the Aggregate Performance Ratings. The weighted distances from ideal solution and anti-ideal solution were calculated after secondary normalization. The proximity of each alternative to the ideal solution was determined as the final step. The alternatives were ranked based on the magnitude of ideal solutions. Results showed that "Public desalinated distribution system" was the most appropriate alternative to supply the drinking needs of Qom population. Also, "PET Bottled Drinking Water" was the second acceptable option. A novel classification of alternatives to satisfy the drinking water requirements was proposed which is applicable for the other cities located in semi-arid regions of Iran. The health issues were considered as independent criterion, distinct from the environmental issues. The constraints of high-tech alternatives were also considered regarding to the level of dependency on overseas. PMID:26221535

  15. Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region.

    Science.gov (United States)

    Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

    2015-01-01

    Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including "Public desalinated distribution system", "PET Bottled Drinking Water", "Private desalinated water suppliers" and "Household desalinated water units" were assessed based on criteria and sub-criteria. Data were aggregated and normalized to apply Performance Ratings of Alternatives. Also, the Performance Ratings of Alternatives were aggregated again to achieve the Aggregate Performance Ratings. The weighted distances from ideal solution and anti-ideal solution were calculated after secondary normalization. The proximity of each alternative to the ideal solution was determined as the final step. The alternatives were ranked based on the magnitude of ideal solutions. Results showed that "Public desalinated distribution system" was the most appropriate alternative to supply the drinking needs of Qom population. Also, "PET Bottled Drinking Water" was the second acceptable option. A novel classification of alternatives to satisfy the drinking water requirements was proposed which is applicable for the other cities located in semi-arid regions of Iran. The health issues were considered as independent criterion, distinct from the environmental issues. The constraints of high-tech alternatives were also considered regarding to the level of dependency on overseas.

  16. Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones

    Science.gov (United States)

    Gil-Sotres, F.; Miralles, I.; Canton-Castilla, Y.; Domingo, F.; Leiros, M. C.; Trasar-Cepeda, C.

    2012-04-01

    involved in C (invertase, CM-cellulase, β-glucosidase), N (urease, BAA-protease, casein-protease) and P (phosphomonoesterase) cycles in BSCs at different successional stages (cyanobacteria represents the first successional stage, lichen Diploschistes diacapsis in an intermediate state and lichen Lepraria crassissima, with the greatest successional state). Our results show that BSCs at lower successional stage enriched the surface geological substrate in hydrolase enzymes to a lesser extent than mature BSCs (Lepraria crassissima), which show the highest values in all enzymatic activities. In contrast, the specific enzyme activities (activity values expressed per unit of carbon) were higher in the BSCs at lower successional stage, decreasing in the direction: cyanobacteria > Diploschistes diacapsis-lichen > Lepraria crassissima-lichen. These results suggest a different role of BSCs depending on their successional stage with regard to the implantation of biogeochemical cycles during the surface substrate colonization. Our conclusions are highly relevant to improve the knowledge of biogeochemical cycles in arid and semiarid areas. Keywords: Biological Soil Crusts, arid ecosystems, hydrolytic enzymes, biochemical activity

  17. Multi-element stream sediment geochemistry of south-western and central Nigeria

    OpenAIRE

    Knights, K.V.; Lapworth, D. J.; Key, R. M.; Johnson, C C; Adekanmi, M.A.; Arisekola, T.M.

    2011-01-01

    This paper presents preliminary results from geochemical baseline stream sediment surveys from two Cells (South-western Cell and Central Cell) in Nigeria completed in 2009. This work was part of the World Bank funded Nigerian Sustainable Management of Mineral Resources Project carried out by the Nigerian Geological Survey Agency in cooperation with the British Geological Survey. A total of 284 stream sediment samples were collected from the South-western Cell, with an average sampling density...

  18. Preparedness of Colleges of Education in Southwestern Nigeria for the Adoption of Blended Learning

    OpenAIRE

    Idowu olusola Olayiwola; Kudirat Mojirade Alimi

    2015-01-01

    The study investigated the preparedness of colleges of education in Southwestern Nigeria in terms of available facilities and infrastructure for the use of blended learning.  The study adopted the survey design. The population consisted of students and lecturers in colleges of education in Southwestern Nigeria. The sample size was 1,059 students and 168 lecturers. Three states were selected from which three colleges of education (one per state) also selected using the random were sampling tec...

  19. Regional validity of the parameters of a distributed runoff-erosion model in the semi-arid region of Brazil

    Institute of Scientific and Technical Information of China (English)

    SRINIVASAN; Vajapeyam; Srirangachar; PAIVA; Fernanda; Maria; de; Lima

    2009-01-01

    The present paper examines the validity of the application of a distributed rainfall-runoff-erosion model on a regional basis in a semi-arid region of Brazil. The model tested is known as WESP (Water Erosion Simulation Program) developed by Lopes (1987). The model simulates the hydrograph and the sediment graph for individual events and thus, the model when properly calibrated can serve as a predictive tool for runoff and soil erosion on an individual or a continuous basis. The possibility of the existence of regionally applicable values for the parameters of the model WESP would be very interesting from the point of view of predictability of runoff and soil erosion from ungauged basins in the region. For this purpose, data collected in several experimental units in the experimental basin of Sumé as well as in the experimental basin of So Joo de Cariri have been used. The model was calibrated and validated in each of the experimental units (consisting of erosion plots and micro-basins) and the average value from all of the units for each of the parameters was considered to be the regional value. With these average values, all the events in all the experimental units were simulated. The results show that the runoff and erosion values simulated with this single parameter set were very good in all the units, being well within the acceptable deviations.

  20. Regional validity of the parameters of a distributed runoff-erosion model in the semi-arid region of Brazil

    Institute of Scientific and Technical Information of China (English)

    SRINIVASAN Vajapeyam Srirangachar; PAIVA Fernanda Maria de Lima

    2009-01-01

    The present paper examines the validity of the application of a distributed rainfall-runoff-erosion model on a regional basis in a semi-arid region of Brazil.The model tested is known as WESP (Water Erosion Simulation Program) developed by Lopes (1987).The model simulates the hydrograph and the sedi-ment graph for individual events and thus, the model when properly calibrated can serve as a predic-tive tool for runoff and soil erosion on an individual or a continuous basis.The possibility of the exis-tence of regionally applicable values for the parameters of the model WESP would be very interesting from the point of view of predictability of runoff and soil erosion from ungauged basins in the region.For this purpose, data collected in several experimental units in the experimental basin of Sume as well as in the experimental basin of Sao Joao de Cariri have been used.The model was calibrated and validated in each of the experimental units (consisting of erosion plots and micro-basins) and the av-erage value from all of the units for each of the parameters was considered to be the regional value.With these average values, all the events in all the experimental units were simulated.The results show that the runoff and erosion values simulated with this single parameter set were very good in all the units, being well within the acceptable deviations.

  1. Survey of Revegetated Areas on the Fitzner/Eberhardt Arid Lands Ecology Reserve: Status and Initial Monitoring Results

    Energy Technology Data Exchange (ETDEWEB)

    Downs, Janelle L.; Link, Steven O.; Rozeboom, Latricia L.; Durham, Robin E.; Cruz, Rico O.; Mckee, Sadie A.

    2011-09-01

    During 2010, the U.S. Department of Energy (DOE), Richland Operations Office removed a number of facilities and debris from the Fitzner/Eberhardt Arid Lands Ecology Reserve (ALE), which is part of the Hanford Reach National Monument (HRNM). Revegetation of disturbed sites is necessary to stabilize the soil, reduce invasion of these areas by exotic weeds, and to accelerate re-establishment of native plant communities. Seven revegetation units were identified on ALE based on soils and potential native plant communities at the site. Native seed mixes and plant material were identified for each area based on the desired plant community. Revegetation of locations affected by decommissioning of buildings and debris removal was undertaken during the winter and early spring of 2010 and 2011, respectively. This report describes both the details of planting and seeding for each of the units, describes the sampling design for monitoring, and summarizes the data collected during the first year of monitoring. In general, the revegetation efforts were successful in establishing native bunchgrasses and shrubs on most of the sites within the 7 revegetation units. Invasion of the revegetation areas by exotic annual species was minimal for most sites, but was above initial criteria in 3 areas: the Hodges Well subunit of Unit 2, and Units 6 and 7.

  2. Rainfall-runoff relationship of some catchments with karstic geomorphology under arid to semi-arid conditions

    Science.gov (United States)

    De Vera, Maximo R.

    1984-02-01

    The relationship between rainfall and runoff of fourteen catchments with a total area of 5983 km 2 in the northeastern zone of Libya was reviewed in an attempt to determine the effect of karstic geomorphology on the runoff coefficient. Available data since 1965 were collated and eight wadis with at least eleven flood events were used for linear regression analysis. The selected catchments are under arid to semi-arid conditions with mean annual rainfall of 50-500 mm and with surface geology consisting mostly of marly limestone which is favourable to karstification phenomena. The ratio of runoff to rainfall is extremely variable with a range of 0.0001-0.830, and therefore it is not a reliable criterion for runoff estimation, especially with the limited data subjected to statistical analysis. The regression analysis shows correlation coefficients from 0.219 to 0.89 with no apparent effect of size of catchment area. As indicated by the coefficient of determination, 4.8-80.3% of the variation in runoff has been accounted for by the regression. The extent and degree of karstification, if properly quantified, can be a significant factor for runoff prediction, in addition to rainfall intensity and duration, antecedent soil moisture, effective catchment area and other geomorphological features.

  3. Onchocerca lupi Nematodes in Dogs Exported from the United States into Canada

    Science.gov (United States)

    Conboy, Gary; Lejeune, Manigandan; Marron, Fany; Hanna, Paul; MacDonald, Erin; Skorobohach, Brian; Wilcock, Brian; Kutz, Susan J.; Gilleard, John S.

    2016-01-01

    The Onchocerca lupi nematode is an emerging helminth capable of infecting pets and humans. We detected this parasite in 2 dogs that were imported into Canada from the southwestern United States, a region to which this nematode is endemic. We discuss risk for establishment of O. lupi in Canada. PMID:27434170

  4. From Segregation to School Finance: The Legal Context for Language Rights in the United States

    Science.gov (United States)

    Powers, Jeanne M.

    2014-01-01

    In this chapter, the author reviews the legal trajectory of language rights in public schooling in the United States and how language has been intertwined with other policy issues in court cases aimed at expanding access and equity for minority students: desegregation and school finance. Most of these cases originated in the Southwestern United…

  5. Improvement of Surface Albedo Simulations over Arid Regions

    Institute of Scientific and Technical Information of China (English)

    BAO Yan; L(U) Shihua; ZHANG Yu; MENG Xianhong; YANG Shengpeng

    2008-01-01

    To improve the simulation of the surface radiation budget and related thermal processes in arid regions, three sophisticated surface albedo schemes designed for such regions were incorporated into the Biosphere-Atmosphere Transfer Scheme (BATS). Two of these schemes are functions of the solar zenith angle (SZA), where the first one has one adjustable parameter defined as SZA1 scheme, and the second one has two empir-ical parameters defined as SZA2 scheme. The third albedo scheme is a function of solar angle and soil water that were developed based on arid-region observations from the Dunhuang field experiment (DHEX) (defined as DH scheme). We evaluated the performance of the original and newly-incorporated albedo schemes within BATS using the in-situ data from the Oasis System Energy and Water Cycle Field Experiment that was carried out in JinTa, Gansu arid area (JTEX). The results indicate that a control run by the original version of the BATS generates a constant albedo, while the SZA1 and SZA2 schemes basically can reproduce the observed diurnal cycle of surface albedo, although these two schemes still underestimate the albedo when SZA is high in the early morning and late afternoon, and overestimate it when SZA is low during noontime. The SZA2 scheme has a better overall performance than the SZA1 scheme. In addition, BATS with the DH scheme slightly improves the albedo simulation in magnitude as compared to that from the control run, but a diurnal cycle of albedo is not produced by this scheme. The SZAl and SZA2 schemes significantly increase the surface absorbed solar radiation by nearly 70 W m~2, which further raises the ground temperature by 6 K and the sensible heat flux by 35 W m~2. The increased solar radiation, heat flux, and temperature are more consistent with the observations that those from the control run. However, a significant improvement in these three variables is not found in BATS with the DH scheme due to the neglect of the diurnal cycle of

  6. Water pulses and biogeochemical cycles in arid and semiarid ecosystems.

    Science.gov (United States)

    Austin, Amy T; Yahdjian, Laura; Stark, John M; Belnap, Jayne; Porporato, Amilcare; Norton, Urszula; Ravetta, Damián A; Schaeffer, Sean M

    2004-10-01

    The episodic nature of water availability in arid and semiarid ecosystems has significant consequences on belowground carbon and nutrient cycling. Pulsed water events directly control belowground processes through soil wet-dry cycles. Rapid soil microbial response to incident moisture availability often results in almost instantaneous C and N mineralization, followed by shifts in C/N of microbially available substrate, and an offset in the balance between nutrient immobilization and mineralization. Nitrogen inputs from biological soil crusts are also highly sensitive to pulsed rain events, and nitrogen losses, particularly gaseous losses due to denitrification and nitrate leaching, are tightly linked to pulses of water availability. The magnitude of the effect of water pulses on carbon and nutrient pools, however, depends on the distribution of resource availability and soil organisms, both of which are strongly affected by the spatial and temporal heterogeneity of vegetation cover, topographic position and soil texture. The 'inverse texture hypothesis' for net primary production in water-limited ecosystems suggests that coarse-textured soils have higher NPP than fine-textured soils in very arid zones due to reduced evaporative losses, while NPP is greater in fine-textured soils in higher rainfall ecosystems due to increased water-holding capacity. With respect to belowground processes, fine-textured soils tend to have higher water-holding capacity and labile C and N pools than coarse-textured soils, and often show a much greater flush of N mineralization. The result of the interaction of texture and pulsed rainfall events suggests a corollary hypothesis for nutrient turnover in arid and semiarid ecosystems with a linear increase of N mineralization in coarse-textured soils, but a saturating response for fine-textured soils due to the importance of soil C and N pools. Seasonal distribution of water pulses can lead to the accumulation of mineral N in the dry season

  7. Conceptual model for water management in Brazilian semi-arid regions: From intervention to sustainability, case of Lagoa Real Uranium Plant

    International Nuclear Information System (INIS)

    The world water lack problem has been already diagnosed and is acknowledged as one of the greatest challenges for this century. The scientific literature, documents and either nationals or internationals official reports like the Brazilian Water Agency (ANA) and UNESCO point out the main shortages and general management practices. Also in Brazil, it is a multi-facet problem that envelops several social agents for many decades and has tragic consequences in some regions of the country, like is the case of the northeastern semi-arid region. This work presents the strategies for expertise integration to attend demands for the establishment of partnerships that include several institutions, with different experiences in the region, to improve the acquaintance with dry climate in Brazilian semi-arid. The general objective was developing a conceptual model of technical multi-institutional arrangements as tools for aquifer management, promoting sustainable use of groundwater in the semi-arid region. Here, we present a conceptual model based in technical, political and socio-economical dimensions of sustainability that exchange information among them and with management requirements. This process must be turned in more productive agricultural systems with the introduction of new technology that respect the family arrangement of the production units. It is also expected that validation of this conceptual model allows an applicable alternative to other areas in the future, respected of course all the geo-socio-economical constraints of each site. (author)

  8. Radiocarbon evidence of the Middle to Upper Palaeolithic transition in Southwestern Europe

    Directory of Open Access Journals (Sweden)

    Jöris, Olaf

    2003-12-01

    Full Text Available In the present paper we systematically evaluate the radiometric database underlying the Middle to Upper Palaeolithc transition in southwestern Europe.The different models which attempt to explain the demographical processes underlying this transition rely to a large degree on radiocarbon chronology. We observe that: 1 with increasing age, dates on bone samples show large offsets against those on charcoal, often underestimating these for several thousand years BP and; 2 there is no proof for a persistence of Middle Palaeolithic industries into the time of the earliest Aurignacian in SW Europe. These data contradict the “Ebro- Frontier” model that distinguishes Late Middle Palaeolithic industries in the SW of the Iberian Peninsula from early Aurignacian ones in the NE. On the contrary, our data 3 imply a model of interregional shifts of populations contracting during severe cold and arid phases and expanding under warmer, interstadial conditions, raising ideas on a regional in situ development of the SW European Aurignacian out of Latest Middle Palaeolithic industries made by Neanderthals some 40.0 kyr cal BC.

    Se presenta un estudio sistemático sobre la información radiometrica disponible para la transición Paleolítico Medio-Paleolítico Superior en el Suroeste de Europa. Los diferentes modelos para explicar el proceso demográfico que subyace en esta transición dependen en gran medida de la cronología radiocarbónica. Se observa que: 1 a mayor antiguedad las fechas sobre hueso muestran una mayor desvisación frente a las muestras sobre carbón, a menudo infravalorando estas varios miles de años BP y 2 que no hay pruebas de perduración de industrias de Paleolítico Medio durante las fases tempranas del Auriñaciense en el SW de Europa. Estos datos contradicen el modelo de “frontera del Ebro” que distingue industrias de Paleolítico Medio Tardío en el SW de la Península Ibérica de las industrias del Auriñaciense temprano

  9. Structural lineaments and neogene volcanism in southwestern Luzon

    Science.gov (United States)

    Wolfe, John A.; Self, Stephen

    The Philippine Islands have at least 15 active composite volcanoes and as many more that are fumarolic or dormant. About 20 calderas of Pleistocene age are known so far. Southwestern Luzon, one of the major volcanic districts of the country, contains three young composite volcanoes, four in a fumarolic stage, and over 200 vents of Pliocene-Pleistocene age within 150 km of Manila. There are three large calderas in this zone with a fourth a short distance south on Mindoro Island, plus four summit calderas. One of the most striking features is the Bataan Lineament, a chain of 27 volcanic vents, only one at present active, which marks the western side of the district. The main segment extends from Naujan caldera in the south (on Mindoro Island) on a strike of N31°W through Batangas Bay caldera, Mataas Na Gulod (a summit caldera), Corregidor Island (a small caldera), to Mount Mariveles and Mount Natib on the Bataan peninsula. With a bend of 30° at Mount Natib, the lineament continues northward for another 100 km, giving a total length of 320 km. Here it includes Mount Pinatubo, which is active, and several other vents. The Bataan Lineament is a volcanic arc, with perhaps some extensional element, above the subduction zone of the Manila Trench, dipping eastward under Luzon. Another major volcanic element is the Verde Island transform, which forms a zone across southwest Luzon, including 10 or more volcanoes. Activity extended from the lower Miocene with periodic eruptions until the late Pleistocene. Two volcanoes may be in a waning (fumarolic) stage and have thermal areas. Near the western end of this lineament, recent rifting may have occurred, and presently it is a zone of intense seismic activity. In the zone between the Bataan and Verde Island lineaments, several major volcanoes have developed including Laguna de Bay and Taal volcano-tectonic depressions. Large volume ignimbrite-forming eruptions may have taken place from Laguna de Bay caldera approximately 1.0 m

  10. Eddies in the southwestern East/Japan Sea

    Science.gov (United States)

    Lee, Dong-Kyu; Niiler, Peter

    2010-10-01

    Closed loop mesoscale eddies were identified and tracked in the Ulleung Basin of the southwestern Japan/East Sea (JES) using the winding-angle (WA) methodology, for mapping the absolute geostrophic currents into surface streamlines of flow. The geostrophic velocity used here was the sum of the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO), time variable velocity and the 1992-2007 mean geostrophic velocity. Local sampling bias was removed using the drifter observations. This WA methodology of deriving the Lagrangian path lines that drifters followed over a 7-day period was validated by individual drifter tracks and it demonstrated closed looping eddy motions. The WA method demonstrated that less than 6% of the closed streamlines appeared when drifters did not show a closed loop in their vicinity, compared to 30% of the excess detection rate by the Okubo-Weiss method of locating closed loop structures. Three groups of eddies were identified: (1) Coastal Cold and Warm Eddies, which appeared in the area between the coast of southern Korea and the East Korean Warm Current (EKWC), when a southward coastal current was present, (2) Frontal Cold and Warm Eddies, which were formed in the region of the seaward extension of the meandering EKWC, north of Ulleung Island and (3) Ulleung Warm Eddies (UWE) and Dok Cold Eddies (DCE), which appeared during meanders of the EKWC, in the Ulleung Basin. No seasonal concentration for eddy generation and eddy population was found. The average radius of eddies was about 38-60 km. These were born, moved in an erratic pattern and then died in the vicinity where the EKWC separated from the coast and formed a large meander. The time-mean large meander formed meridionally concentrated bands of positive and negative relative vorticity. The cyclonic (cold) eddies tend to reside within the band of positive time-mean relative vorticity, and the anticyclonic (warm) eddies reside within the bands of negative relative

  11. Epidemiological Aspects of Dermatophytosis in Khuzestan, southwestern Iran, an Update.

    Science.gov (United States)

    Rezaei-Matehkolaei, Ali; Rafiei, Abdollah; Makimura, Koichi; Gräser, Yvonne; Gharghani, Maral; Sadeghi-Nejad, Batool

    2016-08-01

    Dermatophytosis is among the most common superficial mycoses in Iran. The purpose of this report was to update the clinical and mycological features of human dermatophytosis in the Khuzestan, southwestern Iran. In the framework of a one-year survey, a total of 4120 skin, hair and nail samples obtained from the outpatients with symptoms suggestive of tinea were analyzed by using direct microscopy, culture and molecular identification methods. Strains isolated from cultures were subjected to amplification of the nuclear rDNA ITS regions in a PCR assay followed by an early established RFLP analysis. For confirmation of species identification, 100 isolates as representatives of all presumable species were subjected to ITS sequencing. Infection was confirmed in 1123 individuals (27.25 %) in the age range of 1-89 years by direct microscopy and/or culture including 603 males versus 520 females. Frequencies of infections were the highest and the lowest in age groups of 21-30 and 11-20 years, respectively. Tinea corporis was the most prevalent clinical manifestation followed by tinea cruris, tinea capitis, tinea manuum, tinea pedis, tinea unguium, tinea faciei and tinea barbae. Trichophyton interdigitale (58.7 %) was the most dominant isolate followed by Epidermophyton floccosum (35.4 %), Microsporum canis (3 %), T. rubrum (1.5 %), T. species of Arthroderma benhamiae (0.5 %), T. tonsurans (0.3 %) and T. violaceum (0.3 %). Other species included M. gypseum, M. fulvum and T. verrucosum (each one 0.1 %). Such a high occurrence of infection with T. interdigitale, which has not been reported from Iran, is due to the use of accurate molecular methods based on new species concept in dermatophytes. The prevalence of dermatophytoses caused by zoophilic species remarkably increased and Trichophyton species of A. benhamiae has emerged as a new agent of dermatophytosis in southwestern Iran, while infections due to anthropophilic species, except E. floccosum, took a

  12. Diversity and distribution patterns of root-associated fungi on herbaceous plants in alpine meadows of southwestern China.

    Science.gov (United States)

    Gao, Qian; Yang, Zhu L

    2016-01-01

    The diversity of root-associated fungi associated with four ectomycorrhizal herbaceous species, Kobresia capillifolia, Carex parva, Polygonum macrophyllum and Potentilla fallens, collected in three sites of alpine meadows in southwestern China, was estimated based on internal transcribed spacer (ITS) rDNA sequence analysis of root tips. Three hundred seventy-seven fungal sequences sorted to 154 operational taxonomical units (sequence similarity of ≥ 97% across the ITS) were obtained from the four plant species across all three sites. Similar taxa (in GenBank with ≥ 97% similarity) were not found in GenBank and/or UNITE for most of the OTUs. Ectomycorrhiz a made up 64% of the fungi operational taxonomic units (OTUs), endophytes constituted 4% and the other 33% were unidentified root-associated fungi. Fungal OTUs were represented by 57% basidiomycetes and 43% ascomycetes. Inocybe, Tomentella/Thelophora, Sebacina, Hebeloma, Pezizomycotina, Cenococcum geophilum complex, Cortinarius, Lactarius and Helotiales were OTU-rich fungal lineages. Across the sites and host species the root-associated fungal communities generally exhibited low host and site specificity but high host and sampling site preference. Collectively our study revealed noteworthy diversity and endemism of root-associated fungi of alpine plants in this global biodiversity hotspot. PMID:26740542

  13. Factors Affecting Adoption of Agroforestry Farming System as a Mean for Sustainable Agricultural Development and Environment Conservation in Arid Areas of Northern Kordofan State, Sudan

    International Nuclear Information System (INIS)

    Arid and semi-arid areas represent about 60 percent of Sudan total area. One of the main environmental problems in the arid and semi-arid areas is diffraction's which reduces the natural potential of the already fragile ecosystems and renders rural people vulnerable to food shortages, the vagaries of weather and natural disasters. Deforestation which is considered one of the most critical environmental problems facing the world is one of the main causes of diffraction's. Between the years 1990 and 2005 Sudan lost about 8.8 millions hectares of forests, which represents 11%, of its forests mainly because of subsistence activities such as overgrazing, trees cutting and expansion of traditional agriculture. One of the areas that are very much affected by diffraction's is Northern Kordofan State. To rescue the situation the government of Sudan, with assistance from the United Nations Development Program (UNDP) and some donors, implemented a project that aimed primarily at restocking Acacia Senegal trees in Northern Kordofan State. This study is intended to explore the factors that caused differential rate of farmers' adoption rate of the Acacia Senegal based agroforestry farming system. The study data was collected from a clustered random sample of 300 farmers, through face to face interviews using a questionnaire that was pre-tested and validated. Frequency distribution and multiple regression analysis were used to analyze the data. It has been found that farmers' adoption of agroforestry farming system in Northern Kordofan state was significantly affected by the farmers' level of formal education, contact with extension agents, level of environmental awareness, cosmopoliteness, total area of owned land and extent of social participation. (author)

  14. Pipeline monitoring with interferometry in non-arid regions

    Energy Technology Data Exchange (ETDEWEB)

    McCardle, Adrian; Rabus, Bernhard; Ghuman, Parwant [MacDonald Dettwiler, Richmond, BC (Canada); Freymueller, Jeff T. [University of Alaska, Fairbanks (United States)

    2005-07-01

    Interferometry has become a proven technique for accurately measuring ground movements caused by subsidence, landslides, earthquakes and volcanoes. Using space borne sensors such as the ERS, ENVISAT and RADARSAT satellites, ground deformation can be monitored on a millimeter level. Traditionally interferometry has been limited to arid areas however new technology has allowed for successful monitoring in vegetated regions and areas of changing land-cover. Analysis of ground movement of the Trans-Alaskan pipeline demonstrates how these techniques can offer pipeline engineers a new tool for observing potential dangers to pipeline integrity. Results from Interferometric Point Target Analysis were compared with GPS measurements and speckle tracking interferometry was demonstrated to measure a major earthquake. (author)

  15. Integrated Demonstration program -- Applying innovative technologies to VOC remediation in arid environments

    International Nuclear Information System (INIS)

    Historical activities at US DOE facilities around the United States during World War II, including development of a nuclear deterrent, resulted in the discharge of chemical and radioactive materials to the environment. The DOE has now focused a major technical effort on the mitigation of the effects of those discharges through an environmental restoration program. The DOE Office of Technology Development (OTD) launched a major initiative to develop and demonstrate more cost-effective and safer means of restoring contaminated areas. This initiative integrates available conventional technologies and innovative and/or emerging technologies with ongoing environmental restoration activities. The ultimate goal of the OTD initiative is to have demonstrated technologies available for commercial application when they are needed at DOE sites. A key element of the initiative is the creation of Integrated Demonstrations (IDs). The VOC Arid-ID is providing the mechanism for developing and deploying cradle-to-grave technical solutions using a creative approach for solving environmental cleanup problems at the Hanford site. Within the last 10 months, and from it's inception, the ID has been successful in deploying demonstrated technologies from monitoring and characterization through site remediation. The creation of IDs has provided DOE with a mechanism to accelerate the Hanford site cleanup by bringing technology forward in a timely manner to meet the needs of the stakeholders

  16. Optimal integrated management of groundwater resources and irrigated agriculture in arid coastal regions

    Science.gov (United States)

    Grundmann, J.; Schütze, N.; Heck, V.

    2014-09-01

    Groundwater systems in arid coastal regions are particularly at risk due to limited potential for groundwater replenishment and increasing water demand, caused by a continuously growing population. For ensuring a sustainable management of those regions, we developed a new simulation-based integrated water management system. The management system unites process modelling with artificial intelligence tools and evolutionary optimisation techniques for managing both water quality and water quantity of a strongly coupled groundwater-agriculture system. Due to the large number of decision variables, a decomposition approach is applied to separate the original large optimisation problem into smaller, independent optimisation problems which finally allow for faster and more reliable solutions. It consists of an analytical inner optimisation loop to achieve a most profitable agricultural production for a given amount of water and an outer simulation-based optimisation loop to find the optimal groundwater abstraction pattern. Thereby, the behaviour of farms is described by crop-water-production functions and the aquifer response, including the seawater interface, is simulated by an artificial neural network. The methodology is applied exemplarily for the south Batinah re-gion/Oman, which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture. Due to contradicting objectives like profit-oriented agriculture vs aquifer sustainability, a multi-objective optimisation is performed which can provide sustainable solutions for water and agricultural management over long-term periods at farm and regional scales in respect of water resources, environment, and socio-economic development.

  17. A Multi-Satellite Approach for Water Storage Monitoring in an Arid Watershed

    Directory of Open Access Journals (Sweden)

    Dawit T. Ghebreyesus

    2016-07-01

    Full Text Available The objective of this study was to use satellite imagery to monitor the water budget of Al Ain region in the United Arab Emirates (UAE. Inflows and outflows were estimated and the trend of water storage variation in the study area was examined from 2005 to 2014. Evapotranspiration was estimated using the simplified Penman-Monteith equation. Landsat images were used to determine the extent of agricultural and green areas. Time series of gravity recovery and climate experiment (GRACE observations over the study area were used to assess the inferred water storage variation from satellite data. The change of storage inferred from the Water Budget Equation showed a decreasing trend at an average rate of 2.57 Mm3 annually. Moreover, GRACE readings showed a decreasing trend at a rate of 0.35 cm of water depth annually. Mann-Kendal, a non-parametric trend test, proved the presence of significant negative trends in both time series at a 5% significance level. A two-month lag resulted in a better agreement (R2 = 0.55 between the change in water storage and GRACE anomalies within the study area. These results suggest that water storage in the study area is being depleted significantly. Moreover, the potential of remote sensing in water resource management, especially in remote and arid areas, was demonstrated.

  18. Bacterial Diversity within the Extreme Arid Atacama Desert Soils of the Yungay Region, Chile

    Science.gov (United States)

    Connon, S. A.; Lester, E. D.; Shafaat, H. S.; Obenhuber, D. C.; Ponce, A.

    2006-12-01

    Surface and subsurface soil samples analyzed for this study were collected from the hyper-arid Yungay region of the Atacama Desert, Chile. This is the first report of microbial diversity from DNA extracted directly from these extremely desiccated soils. Our data shows that 94% of the 16S rRNA genes cloned from these soils belong to the Actinobacteria phylum. A 24-hour time course series showed a diurnal water activity (aw) cycle that peaked at 0.52 in the early predawn hours, and ranged from 0.08 0.01 during the day. All measured water activity values were below the level required for microbial growth or enzyme activity. Total organic carbon (TOC) levels in this region were just above the limits of detection and ranged from 220 660 μg/g of soil. Phospholipid fatty acid (PLFA) levels indicated cellular biomass ranging from 2 ×105 to 7 ×106 cell equivalents per gram of soil. The culturable counts were low with most samples showing no growth on standard plates of R2A medium; the highest single count was 47 colony forming units (CFU) per gram.

  19. Dairy Heifer Rearing in Hot Arid Zone: An Economic Assessment

    Directory of Open Access Journals (Sweden)

    M. A. Razzaque

    2010-01-01

    Full Text Available Problem statement: Economic losses due to high mortality in young calves born in hot arid zone including Kuwait and a high cost of rearing are the main constraints to this region. Therefore, dairy producers have to depend on importation of pregnant heifers for herd replacement. Research data on cost of heifer rearing from their weaning to first lactation were lacking. The objectives of the present investigation were to compare the costs/benefits of raising heifers born in Kuwait without and with intervention measures and project the future financial benefits. Approach: Present study methods involved using cost-benefit model where without and with intervention scenarios were compared using a total of 58 herd parameters. These variables included in the spreadsheets in the model could be varied during each year of projection period. Production turnoff of 3 herds each of 245 cows in three scenarios namely baseline, improved and future were evaluated. Input costs of imported heifers (baseline, locally raised heifers with interventions (improved and projected 10 year (future and the income generated from these scenarios were analyzed. Results: Total income generated from baseline, improved and the future projection were KD 268,715/-, 281,246/-and 342,251/-respectively (1 KD Kuwaiti Dinar = US $3.45; total operating costs of these scenarios were KD 249,372/-, 242,276/-and 205,929/-respectively. Financial analyses showed that benefits were double when interventions were applied KD 19,343/-Vs KD 38,970/-in baseline and improved operation respectively. Conclusion: Fifty percent of the total heifers needed for herd replacement could be sourced locally showing an increased net income as an outcome of intervention measures. Locally born adapted heifers could be used for dairying in this hot arid zone with a phase-wise increase in their herd size reducing dependence on imported dairy cattle.

  20. Designing of zero energy office buildings in hot arid climate

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gwad, Mohamed

    2011-07-01

    The designing of office buildings by using large glass areas to have a transparent building is an attractive approach in the modern office building architecture. This attitude increases the energy demand for cooling specially in the hot arid region which has long sun duration time, while the use of small glazing areas increases the energy demand for lighting. The use of uncontrolled natural ventilation increases the rate of hot ambient air flow which increases the building energy demand for cooling. At the same time, the use of mechanical ventilation to control the air change rate may increase the energy demand for fans. Some ideas such as low energy design concept are introduced for improving the building energy performance and different rating systems have been developed such as LEED, BREEAM and DGNB for evaluating building energy performance system. One of the new ideas for decreasing the dependence on fossil fuels and improving the use of renewable energy is the net zero-energy building concept in which the building generates enough renewable energy on site to equal or exceed its annual energy use. This work depends on using the potentials of mixing different energy strategies such as hybrid ventilation strategy, passive night cooling, passive chilled ceiling side by side with the integrating of photovoltaic modules into the building facade to produce energy and enrich the architectural aesthetics and finally reaching the Net Zero Energy Building. There are different definitions for zero energy buildings, however in this work the use of building-integrated Photovoltaic (BIPV) to provide the building with its annual energy needs is adopted, in order to reach to a Grid-Connected Net-Zero Energy Office Building in the hot arid desert zone represented by Cairo, Egypt. (orig.)

  1. Performance of pearl millet hybrids under arid conditions

    Directory of Open Access Journals (Sweden)

    V.K. Manga, and Arun Kumar

    2011-09-01

    Full Text Available Sixteen male-sterile lines of pearl millet (Pennisetum glaucum (L. R. Br. found promising at CAZRI, Jodhpur were crossed with nine diverse restorers from different sources in this region, in a line x tester fashion to develop 144 hybrid combinations, with the objective to identify suitable A lines, R lines and hybrid combinations for arid Rajasthan. These hybrids were evaluated at three different locations in western Rajasthan (Tinwari, Pali and Jodhpur during the rainy season of 2003. Eighteen promising hybrids based upon their performance over locations during 2003, were again evaluated in larger plots during the rainy season of 2004. Considering grain yield over all the five locations during the two seasons 2003 and 2004, ten high yielding hybrids were identified. Among these hybrids grain yield ranged from 1932 kg/ha to 2293 kg/ha, and flowering time from 43 to 48 days. The highest yielding hybrid was ICMA 96111 x RIB-3135-18 followed by ICMA 98333 x RIB-3135-18, ICMA 98222 x CZI 9621, ICMA 98004 x RIB-3135-18, ICMA 97555 x RIB-3135-18 and ICMA 95555 x H 77/833-2. It was observed that the restorer lines RIB-3135-18, CZI 9621, H77/833-2, CZI 1676-2, MIR 97171 and ICMR 356 gave high yielding hybrids. Similarly male sterile lines, ICMA 98222, ICMA 97555 and ICMA 98004 were involved in promising hybrid combinations. The hybrid ICMA 98222 x CZI 9621, which was one of the top five high yielding hybrids, ranked first in a multilocation trial conducted during the rainy season of 2005, at Jodhpur, Bawal, Durgapura and Bikaner, representing extreme arid conditions. This hybrid again recorded 12.8% and 6.6% higher grain yield over national checks GHB 538 and ICMH 356 respectively in Initial hybrid trial 2007, and was promoted to the Advance Hybrid and Population Trial for Kharif 2008.

  2. Rainfall partitioning by desert shrubs in arid regions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    We measured the rainfall partitioning among throughfall, stemflow, and interception by desert shrubs in an arid region of China, and analyzed the influence of rainfall and canopy characteristics on this partitioning and its ecohydrological effects. The percent-ages of total rainfall accounted for by throughfall, stemflow, and interception ranged from 78.85±2.78 percent to 86.29±5.07 per-cent, from 5.50±3.73 percent to 8.47±4.19 percent, and from 7.54±2.36 percent to 15.95±4.70 percent, respectively, for the four shrubs in our study (Haloxylon ammodendron, Elaeagnus angustifolia, Tamarix ramosissima, and Nitraria sphaerocarpa). Rain-fall was significantly linearly correlated with throughfall, stemflow, and interception (P < 0.0001). The throughfall, stemflow, and interception percentages were logarithmically related to total rainfall (P < 0.01), but were quadratically related to the maximum 1-hour rainfall intensity (P < 0.01). The throughfall and stemflow percentages increased significantly with increasing values of the rainfall characteristics, whereas the interception percentage generally decreased (except for average wind speed, air temperature, and canopy evaporation). Regression analysis suggested that the stemflow percentage increased significantly with increasing crown length, number of branches, and branch angle (R2 = 0.92, P < 0.001). The interception percentage increased significantly with increasing LAI (leaf area index) and crown length, but decreased with increasing branch angle (R2 = 0.96, P < 0.001). The mean funnelling percentages for the four shrubs ranged from 30.27±4.86 percent to 164.37±6.41 percent of the bulk precipitation. Much of the precipitation was funnelled toward the basal area of the stem, confirming that shrub stemflow conserved in deep soil layers may be an available moisture source to support plant survival and growth under arid conditions.

  3. Time Profile of Three Semi-Arid Ecosystems in Africa

    Science.gov (United States)

    Anyamba, A.; Damoah, R.; Small, J. L.; Tucker, C. J.

    2015-12-01

    We examine the spatio-temporal variability of rainfall and satellite derived-vegetation index of three endorheic semi-arid ecosystems in Africa: Lake Chad (in the Sahel region), Okavango and Etosha (Southern Africa) to infer the nature and trends of the variability during the satellite data instrumental record. We utilize African Rainfall Climatology Precipitation Estimates (1983-2014) and Normalized Difference Vegetation Index (NDVI) derived from the Advanced Very High Resolution Radiometer (AVHRR: 1981-2014) and Moderate Resolution Imaging Spectroradiometer (MODIS: 2001:2014) to examine the aspects of the annual cycle and interannual variability using both time series plots and time-space diagrams. With respect to Lake Chad region, the first two decades of the series (1981-2000) show predominantly dryer than long-term average conditions with the periods 1989, 1992 and 1996/1997 as the signature drought periods coinciding with the desiccation of the Sahel region during the 1980s to early 1990s decades. The period 2000 to present is dominated by above average rainfall and NDVI with 2003, 2007 and 2012 being the most pronounced wet/greener years. The southern African ecosystems (Okavango and Etosha) show more or less a similar temporal pattern to that of Lake Chad basin, however, the wet periods are more amplified and persistent especially 2000, 2006, 2010 and 2014, with corresponding above average NDVI departures. The amplified nature of wet and dry periods present in the southern African ecosystem time series are consistent with the El Niño Southern Oscillation teleconnection patterns. Overall these three ecosystems serve as detectable fingerprints of changing climate conditions and ecosystems in these arid regions.

  4. Various ARID1A expression patterns and their clinical significance in gastric cancers.

    Science.gov (United States)

    Kim, Young-Bae; Ham, In-Hye; Hur, Hoon; Lee, Dakeun

    2016-03-01

    AT-rich interactive domain 1A (ARID1A) is frequently mutated in gastric cancers, and loss of ARID1A expression is considered a poor prognostic factor in various cancers. However, in practice, ARID1A shows various expression patterns, and our understanding of its significance is limited. We performed immunohistochemistry for ARID1A, MLH1, and pS6 using whole tissue blocks of 350 gastric cancers and classified the ARID1A expression as follows: retained (63.7%), reduced (17.7%), complete loss (14.9%), and partial loss (3.7%). Complete/partial loss was more common in poorly differentiated histology (P hazard ratio [HR], 1.732; P = .015) and OS (HR, 1.751; P = .013). Worse DFS (HR, 2.672; P = .005) and OS (HR, 2.531; P = .002) were also noted in the group with partial loss. High expression of pS6 was observed more frequently in groups showing altered ARID1A expression patterns (P understanding ARID1A with implications for future research and therapeutics. PMID:26826411

  5. Tobacco Use among Health Care Workers in Southwestern Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed A. Mahfouz

    2013-01-01

    Full Text Available The present study targeted health care workers (HCWs in Governmental Hospitals and Primary Health Care Centers in Abha City, southwestern Saudi Arabia. An anonymous self-report questionnaire was used to assess tobacco use and the reasons for smoking. The present study included 736 HCWs. The overall prevalence of tobacco use amounted to 26.3% (14.8% current and 11.5% former users. In a binary logistic regression analysis, males were found significantly more prone to smoke compared to females (aOR = 3.081, 95% CI: 2.004–4.739. Similarly, parental history of tobacco use was found to be a significant risk factor (aOR = 1.540, 95% CI: 1.040–2.278. Among current users, 89.9% were interested in quitting and 66.1% tried before to quit. The prevalence of smoking among HCWs in the present study, besides being a public health problem, represents a potential barrier in involving this group as a first line for tobacco control. There is a need for a national intervention programme in the country in a tailored manner for HCWs to control tobacco use parallel to the running national program for public. These interventions should begin early in basic medical education and to be applied continually during one’s medical career.

  6. Selected data from thermal-spring areas, southwestern Montana

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.B.; Brosten, T.M.; Midtlyng, N.A.

    1978-05-01

    During 1975 to 1977 the Montana district of the US Geological Survey collected and assembled data describing the flow, temperature, and chemical characteristics of thermal and related waters. The work was part of an assessment of the geothermal resources of southwestern Montana, excluding Yellowstone Park. Representative data are presented here from 24 thermal springs and 3 deep wells where water temperatures exceed 38/sup 0/C (100/sup 0/F). Initially, the data base included references reported by Waring (1965). The data base also included unpublished chemical analyses of water samples and related data collected during 1959 to 1973 by the Montana State Board of Health (now Montana Department of Health and Environmental Sciences), the Montana Bureau of Mines and Geology, and by graduate students for theses. Results of analyses and engineering reports were collected from landowners, and additional published and unpublished data were collected by Geological Survey investigators during 1967 to 1975. Tabulation of the data revealed wide discrepancies in reported parameters for some sites. Inadequate description of the sampling sites limited the value of much of the previously reported data, because most of the thermal springs were characterized by multiple outlets. Field measurements of rate, specific conductance, pH, and temperature of flow at the various outlets, particularly those having the highest temperatures, were compared with previously reported determinations.

  7. Ecosystem biophysical memory in the southwestern North America climate system

    International Nuclear Information System (INIS)

    To elucidate the potential role of vegetation to act as a memory source in the southwestern North America climate system, we explore correlation structures of remotely sensed vegetation dynamics with precipitation, temperature and teleconnection indices over 1982–2006 for six ecoregions. We found that lagged correlations between vegetation dynamics and climate variables are modulated by the dominance of monsoonal or Mediterranean regimes and ecosystem-specific physiological processes. Subtropical and tropical ecosystems exhibit a one month lag positive correlation with precipitation, a zero- to one-month lag negative correlation with temperature, and modest negative effects of sea surface temperature (SST). Mountain forests have a zero month lag negative correlation with precipitation, a zero–one month lag negative correlation with temperature, and no significant correlation with SSTs. Deserts show a strong one–four month lag positive correlation with precipitation, a low zero–two month lag negative correlation with temperature, and a high four–eight month lag positive correlation with SSTs. The ecoregion-specific biophysical memories identified offer an opportunity to improve the predictability of land–atmosphere interactions and vegetation feedbacks onto climate. (letter)

  8. Is southwestern China experiencing more frequent precipitation extremes?

    International Nuclear Information System (INIS)

    Climate extremes have and will continue to cause severe damages to buildings and natural environments around the world. A full knowledge of the probability of the climate extremes is important for the management and mitigation of natural hazards. Based on Mann–Kendall trend test and copulas, this study investigated the characteristics of precipitation extremes as well as their implications in southwestern China (Yunnan, Guangxi and Guizhou Province), through analyzing the changing trends and probabilistic characteristics of six indices, including the consecutive dry days, consecutive wet days, annual total wet day precipitation, heavy precipitation days (R25), max 5 day precipitation amount (Rx5) and the rainy days (RDs). Results showed that the study area had generally become drier (regional mean annual precipitation decreased by 11.4 mm per decade) and experienced enhanced precipitation extremes in the past 60 years. Relatively higher risk of drought in Yuanan and flood in Guangxi was observed, respectively. However, the changing trends of the precipitation extremes were not spatially uniform: increasing risk of extreme wet events for Guangxi and Guizhou, and increasing probability of concurrent extreme wet and dry events for Yunnan. Meanwhile, trend analyses of the 10 year return levels of the selected indices implied that the severity of droughts decreased in Yunnan but increased significantly in Guangxi and Guizhou, and the severity of floods increased in Yunnan and Guangxi in the past decades. Hence, the policy-makers need to be aware of the different characterizations and the spatial heterogeneity of the precipitation extremes. (letters)

  9. Acoustic habitat of an oceanic archipelago in the Southwestern Atlantic

    Science.gov (United States)

    Bittencourt, Lis; Barbosa, Mariana; Secchi, Eduardo; Lailson-Brito, José; Azevedo, Alexandre

    2016-09-01

    Underwater soundscapes can be highly variable, and in natural conditions are often dominated by biological signals and physical features of the environment. Few studies, however, focused on oceanic islands soundscapes. Islands in the middle of ocean basins can provide a good example of how untouched marine soundscapes are. Autonomous acoustic recordings were carried out in two different seasons in Trindade-Martin Vaz Archipelago, Southwestern Atlantic, providing nearly continuous data for both periods. Sound levels varied daily and between seasons. During summer, higher frequencies were noisier than lower frequencies, with snapping shrimp being the dominating sound source. During winter, lower frequencies were noisier than higher frequencies due to humpback whale constant singing. Biological signal detection had a marked temporal pattern, playing an important role in the soundscape. Over 1000 humpback whale sounds were detected hourly during winter. Fish vocalizations were detected mostly during night time during both summer and winter. The results show an acoustic habitat dominated by biological sound sources and highlight the importance of the island to humpback whales in winter.

  10. Infrared images of core sediments offshore southwestern Taiwan

    Science.gov (United States)

    Chiang, H. T.; Chuang, Y. H.

    2015-12-01

    The core sediments may retain the negative thermal anomaly caused by the gas hydrate dissociation on the way uploading from sea floor. To identify the signal of negative thermal anomaly, fifteen infrared images of core sediments with tens of meter in length have been analyzed the temperature distribution off southwestern Taiwan. This study results show that most of the core sediments were found lots of gaps with spiking pattern recognition of high temperature on the lower portions. The geochemistry study suggested that the gas in gaps and the sediments were mainly composed of methane which may be the indicators of gas hydrate dissociation in the higher temperature and lower pressure environment. The thermal gradients 0.044-0.114 ℃/m of core sediments are close to the observations in situ by the measurements of temperature probes that thermal gradient are 0.06-0.09 ℃/m. The temperature of all core sediments are greater than 20 ℃. It is obvious that the temperature of core sediments were increased tremendously by the heating of sea water. We found eight out of fifteen core sediments with significant negative thermal anomaly 0.4-1.0 ℃ in different depth between 2 and 10 meters below sea floor. Compare to the experiment in lab that the temperature could be decreased 1.1-1.5 ℃ due to the gas hydrate dissociation, the quantity of the negative thermal anomaly of the core sediments are possible related to the gas hydrate dissociation.

  11. Structural controls of hot-spring systems on southwestern Montana

    Science.gov (United States)

    Chadwick, Robert A.; Leonard, Robert Benjamin

    1979-01-01

    Thermal waters that issue as hot (more than 38C) springs in southwestern Montana appear to circulate to depth along Cenozoic block faults, deep fractures penetrating the dominantly crystalline rock crust, or major structural lineaments. At individual hot springs, rising thermal waters are transmitted along conduits formed by the intersection of a major fault with other faults, fracture zones, anticlinal axes (which may be faulted or fractures), or sedimentary aquifers. Step faults and other intra-valley faults may influence circulation at some springs. At others, fracture zones alone may provide the necessary vertical permeability. Normal regional heat apparently is sufficient to maintain the hydrothermal systems without enhancement from cooling igneous bodies. The thermal gradient normally is higher in low thermal conductivity sediments of the block-fault valleys than the 30C per kilometer average for crystalline rock. To attain reservoir temperatures of 60 to 120C indicated by chemical geothermometers, waters would have to circulate to depths of about 2 to 4 kilometers in crystalline rock and about 1 to 2 kilometers in valley sediments. (Kosco-USGS)

  12. Babesia bovis infection in cattle in the southwestern Brazilian Amazon.

    Science.gov (United States)

    Brito, Luciana G; Rocha, Rodrigo B; Barbieri, Fábio da S; Ribeiro, Elisana S; Vendrami, Fabiano B; Souza, Gislaine C R; Giglioti, Rodrigo; Regitano, Luciana C A; Falcoski, Thaís O R S; Tizioto, Polyana C; Oliveira, Márcia C S

    2013-02-01

    The present study provides the first epidemiological data on infection with Babesia bovis in cattle raised in the southwestern Brazilian Amazon. Blood clot samples were filtered through nylon cloth before being submitted to DNA extraction. PCR and nested-PCR were applied to assess the frequency of infection with B. bovis in calves with ages from 4 to 12 months bred in 4 microregions each in the states of Rondônia and Acre. After the DNA was extracted from the samples, the infection in cattle was investigated by amplification of the "rap1" gene from B. bovis. The DNA amplification results revealed a frequency of infection with B. bovis of 95.1% (272/286) in the samples from Rondônia and 96.1% (195/203) in those from Acre. The high frequency of B. bovis infection in the animals with ages from 4 to 12 months indicates a situation of enzootic stability in the regions studied. The infection rates are comparable to those detected by immunodiagnostic techniques in other endemic regions of Brazil. PMID:23312480

  13. Cross Sectional Attitudes of Public Sculpture Matrix in Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Moses Akintunde Akintonde

    2016-06-01

    Full Text Available Public outdoor sculpture practice in the Southwestern Nigeria entails different types of attitudes. These attitudes are discernable from the stage of commissioning of work, its conceptualization to the display and uses in the public sphere generated diverse fundamental, constant technical issues. Some are explicitly alluring while others are absurd, fleeting and injurious to the practice. However, whatever attitude advanced in the public outdoor sculpture practice, it has not been discussed cross sectionally. The inadequate scholarship attention on the attitudinal issues in outdoor sculpture certainly created art historical gap apt to make the study of contemporary Nigeria art incoherent. Apparently, attitudinal studies certainly involve psychological measurement - a type of instrument that does not required descriptive survey. For this reason, the study was based on qualitative methods. The study categorised various attitudes in outdoor sculpture practice in the studied area into pre-unveiling, unveiling and post unveiling stages and critically examined them. Some attitudes in the practice of the art were observed to be stimulant for advancement; invariably others are clearly incongruous to the spirit of typical Yoruba societal value orientation in orderliness, therefore degrading and detrimental to the development of the outdoor sculpture in the public sphere.

  14. Drought-induced vegetation stress in southwestern North America

    International Nuclear Information System (INIS)

    Trends towards earlier greenup and increased average greenness have been widely reported in both humid and dry ecosystems. By analyzing NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data from 1982 to 2007, we report complex trends in both the growing season amplitude and seasonally integrated vegetation greenness in southwestern North America and further highlight regions consistently experiencing drought stress. In particular, greenness measurements from 1982 to 2007 show an increasing trend in grasslands but a decreasing trend in shrublands. However, vegetation greenness in this period has experienced a strong cycle, increasing from 1982 to 1993 but decreasing from 1993 to 2007. The significant decrease during the last decade has reduced vegetation greenness by 6% in shrublands and 13% in grasslands (16% and 21%, respectively, in the severe drought years). The greenness cycle correlates to both annual precipitation and dry season length derived from NOAA North America Regional Reanalysis data. If drought events continue as predicted by climate models, they will exacerbate ecosystem degradation and reduce carbon uptake.

  15. Permian karst topography in the Wichita uplift, southwestern Oklahoma

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, R.N. Busbey, A.B. (Texas Christian Univ., Ft. Worth, TX (United States). Geology Dept.)

    1993-02-01

    The Wichita uplift in southwestern Oklahoma is one part of a record of Pennsylvania and early Permian deformation that affected the Southern Oklahoma aulacogen. As a result of a partial inversion, the Lower Paleozoic section of this aulacogen was sequentially stripped off an uplift between the Wichita uplift and the Anadarko basin, resulting in the exposure of ultrabasic rocks deep in the Cambrian igneous fill of the aulacogen. Following the late Paleozoic tectonism, the topography of the uplift was entombed beneath Permian sediments and remained essentially undisturbed until exhumation during the present erosional cycle. Modern erosion is gradually exposing this topography, permitting morphometric analysis of the Permian hill forms. Because of the variation of lithology in the uplift, it is possible to isolate the effects of weathering processes such as intense hydrolysis of the igneous rocks (producing, among other features, or topography) and limestone dissolution, in the form of a surface and subsurface karst imprint. The latter process resulted in a network of small caves that are essentially fissures eroded along tectonic fractures. These small caves can be found in all the exposed areas of limestone. They are particularly noteworthy for three reasons: in at least five examples they contain a complex fauna of Permian vertebrates (mostly fragmentary), speleothems in some examples contain hydrocarbon inclusions, derived from the underlying Anadarko basin, some of the caves yield evidence of post burial evolution in the form of clay infiltration from the surface and brine flushing from the underlying Anadarko basin.

  16. Orchid conservation in the biodiversity hotspot of southwestern China.

    Science.gov (United States)

    Liu, Qiang; Chen, Jin; Corlett, Richard T; Fan, XuLi; Yu, DongLi; Yang, HongPei; Gao, JiangYun

    2015-12-01

    Xishuangbanna is on the northern margins of tropical Asia in southwestern China and has the largest area of tropical forest remaining in the country. It is in the Indo-Burma hotspot and contains 16% of China's vascular flora in medicinal or ornamental value) was significantly related to endangerment. Expansion of rubber tree plantations was less of a threat to orchids than to other taxa because only 75 orchid species (17.6%) occurred below the 1000-m-elevation ceiling for rubber cultivation, and most of these (46) occurred in nature reserves. However, climate change is projected to lift this ceiling to around 1300 m by 2050, and the limited area at higher elevations reduces the potential for upslope range expansion. The Xishuangbanna Tropical Botanical Garden is committed to achieving zero plant extinctions in Xishuangbanna, and orchids are a high priority. Appropriate in and ex situ conservation strategies, including new protected areas and seed banking, have been developed for every threatened orchid species and are being implemented. PMID:26372504

  17. The melliferous potential of apiflora of southwestern Vojvodina (Serbia

    Directory of Open Access Journals (Sweden)

    Mačukanović-Jocić Marina P.

    2016-01-01

    Full Text Available The individual and community-level melliferous potential of apiflora was evaluated in southwestern Vojvodina in order to assess its significance and contribution to the bee pasture. Seven plant communities belonging to ruderal, segetal and floodplain type of vegetation, with a total of 279 plant species were registered. Apifloristic and phytocoenological investigations included the determination and analysis of honey plants using the following parameters: total number, percentage, abundance and frequency of these species in the communities, as well as their intensity of pollen and nectar production. The coenotic coefficient of melliferousness (CCm indicating the melliferous potential of each community, was calculated based on the above parameters. Although the greatest number of melliferous species was found in the ass. Chenopodio-Ambrosietum artemisiifoliae (132, the highest percentage (80% of them was registered in the ass. Consolido-Polygonetum avicularis. Considering the coefficients of nectar and pollen production, the most valuable honey plants commonly present in the majority of communities were: Cirsium arvense, Rubus caesius, Lythrum salicaria, Daucus carota, Trifolium pratense, Dipsacus laciniatus, Medicago sativa, Asclepias syriaca, Cichorium intybus and Taraxacum officinale. The low abundance and frequency of melliferous species within the Consolido-Polygonetum avicularis, Polygonetum convolvulo-avicularis and Populetum nigrae-albae communities indicated their poor contribution to the bee pasture. Within ruderal vegetation, the highest CCm was registered in Amorpho-Typhaetum, providing, theoretically, the richest food resource for the honeybees in the investigated area. [Projekat Ministarstva nauke Republike Srbije, br. 46009 i br. 173018

  18. Daily movements of female mallards wintering in Southwestern Louisiana

    Science.gov (United States)

    Link, P.T.; Afton, A.D.; Cox, R.R.; Davis, B.E.

    2011-01-01

    Understanding daily movements of waterfowl is crucial to management of winter habitats, especially along the Gulf Coast where hunting pressure is high. Radio-telemetry was used to investigate movements of female Mallards (Anas platyrchychos) wintering in southwestern Louisiana. Movement distances were analyzed from 2,455 paired locations (diurnal and nocturnal) of 126 Mallards during winters 2004-2005 and 2005-2006 to assess effects of winter, female age, areas closed (Lacassine National Wildlife Refuge [LAC], Cameron Prairie National Wildlife Refuge [CAM], Amoco Pool [AMOCO] or open to hunting [OPEN]), and habitat type, including all interactions. Movement distances from the various land management categories were not consistent by age, date, or by winter. Flight distances from LAC increased with date, whereas those from CAM and OPEN did not vary significantly by date. Female Mallards moved short distances between diurnal and nocturnal sites (ranging from 3.1 to 15.0 km by land management category), suggesting that they are able to meet their daily energy requirements within a smaller area than Northern Pintails (Anas acuta, hereafter Pintails), and thus minimize transit energy costs.

  19. Acidic deposition and its effects in southwestern China

    International Nuclear Information System (INIS)

    The emissions of SO2 in China correspond at present to 8-10 TgSy-1. The rapid industrialization has caused a dramatic increase in the emissions in recent years and this increase is likely to continue. This paper describes studies of concentrations and effects of acidifying substances in parts of the Guizhou and the Sichuan provinces where the S-emissions are large, mainly coming from coal combustion. A small catchment about 10 km from Guiyang centre was equipped with instruments for studies of soils, soil water and streamwater chemistry. The molar ratio Al/(Ca + Mg) is > 0.8 in soil water in some places. Two small streams have median pH-values about 4.6 and 5.1. Laboratory studies with selected Chinese soils showed that the anion adsorption was low. These studies gave also important information on soil sensitivity. The studies confirm that acid deposition may affect soils in parts of south-western China, but the sensitivity varies dramatically and there is a strong need for more information. 11 refs., 3 tabs., 3 figs

  20. Larval habitats of mosquito fauna in Osogbo metropolis, Southwestern Nigeria

    Institute of Scientific and Technical Information of China (English)

    Monsuru Adebayo Adeleke; Wasiu Olalekan Adebimpe; AbdulWasiu Oladele Hassan; Sunday Olukayode Oladejo; Ismail Olaoye; Ganiyu Olatunji Olatunde; Taiwo Adewole

    2013-01-01

    Objective:To determine the larval habitats of mosquito fauna and possible impact of land use/land cover changes on the epidemiology of mosquito-borne diseases in Osogbo metropolis, Southwestern, Nigeria. Methods: All accessible larval habitats were surveyed between May and September, 2011 in Osogbo metropolis while Land Use/ Land cover of the city was analyzed using 2 Lansat Multispectral Scanner satellite imagery of SPOT 1986 and LANDSAT TM 2009. Results:A total of six species namely, Aedes aegypti, Aedes albopictus, Aedes vittatus, Anopheles gambiae complex, Culex quinquefasciatus and Eretmapodite chrysogaster were encountered during the study. The occurrence and contribution of disused tyres was significantly higher (P0.05). The accessible land use/land covered of the study area between 1986 and 2009 showed that the wet land coverage and settlement area increased from 0.19 to 9.09 hectare and 1.00 to 2.01 hectare respectively while the forest area decreased from 60.18 to 50.14 hectare. Conclusion: The contribution of the habitats coupled with the increasing rate of flooded environment which could provide ample breeding sites for mosquitoes call for sustained environmental sanitation and management in Osogbo metropolis.

  1. MIDDLE TRIASSIC AUTOCLASTIC DEPOSITS FROM SOUTHWESTERN BOSNIA AND HERZEGOVINA

    Directory of Open Access Journals (Sweden)

    Duje Smirčić

    2016-06-01

    Full Text Available Middle Triassic volcanic and volcaniclastic rocks have been recognized at several localities near Bosansko Grahovo, in southwestern part of Bosnia and Herzegovina in the External Dinarides. Peculiar types of autoclastic rocks were investigated. These are peperites and hyaloclastites. Regarding specific structures, mineral composition and micropetrographic characteristics it was possible to further differentiate hyaloclastites into in situ hyaloclastites and slightly resedimented hyaloclastites that represent genetic succession. All rock types occurred in a deep sea troughs that formed as a consequence of Middle Triassic extensional tectonic and rift related wrench faulting. In situ hyaloclastites and slightly resedimented hyaloclastites were formed due to quenching at the contact of lava effusions with sea water. Genesis of peperites is related to lava emplacement in unconsolidated water saturated lime mudstones that were deposited in deep sea basin. All investigated rock types represent first findings of autoclastic deposits in the External Dinarides. Biostratigraphic constraints achieved by means of conodont species Neogondolella excentrica, Paragondolella excelsa, Paragondolella trammeri and Gladigondolella tethydis indicate Late Anisian to Early Ladinian interval of the autoclastic deposits from Bosansko Grahovo.

  2. Allochthonous Matter Input in Five Headwater Streams in Southwestern Colombia

    Science.gov (United States)

    Chara, J.; Baird, D.; Telfer, T.

    2005-05-01

    In order to determine the interactions between riparian vegetation and the stream environment in relation to the provision and seasonality of allochthonous energy, a study was done measuring the amount of litter inputs in five streams at mid altitude in southwestern Colombia during one year. Direct and lateral litter traps were placed in a 100m reach of each stream. Total amount of litter fall ranged from 1406 to 2812 g-m-2 year-1. Leaves were the most important component of the litter representing between 56 to 72% of direct and between 68 to 81% of lateral inputs. Seasonality of litter fall was minimal and only in one stream direct input was negatively correlated with rainfall (r=-0.62; p=0.033). According to these results, low-order streams in middle altitude in Colombia receive one of the highest amounts of litter fall reported so far. This supply is constant throughout the year providing a continuous source of food and substrate for the stream environment. As in temperate streams litterfall in the Andean zone is an important link between streams and the riparian environment. The higher amount recorded and the constant supply demonstrate that deforestation of riparian forests may be more negative for the streams in tropical areas.

  3. Some geophysical constraints to dynamic processes in the Southwestern Mediterranean

    Directory of Open Access Journals (Sweden)

    P. Chiozzi

    1996-06-01

    Full Text Available The total tectonic subsidence, thermal state and seismotectonic regime have been analysed to better constrain the dynamic processes which originated the basins of the Southwestern Mediterranean. It is argued that backarc extension and oceanic spreading are the possible and main processes which took place within a compressional framework, driven by the interaction between the African and European plates. As inferred by both subsidence and heat-flux data, in the central part of the Algerian-Balearic basin the crust is oceanic, 20 Ma old on average, originated by a spreading phase, which also affected the Ligurian-Provençal basin. The Alboran basin, which is underlain by stretched continental crust, shows an intermediate seismic activity and a few deep events, explainable by a gravitational collapse of cold lithosphere. After a review of the most recent geodynamical hypotheses, an evolutionary scheme is attempted envisaging the lateral continental escape of the Gibraltar arc. Within a convergent tectonic framework, some lithospheric material could translate almost perpendicular to the convergence direction, and undergo a lateral subduction process, secondary to the main boundary between plates.

  4. Tropical Warm Semi-Arid Regions Expanding Over Temperate Latitudes In The Projected 21st Century

    Science.gov (United States)

    Rajaud, A.; de Noblet, N. I.

    2015-12-01

    Two billion people today live in drylands, where extreme climatic conditions prevail, and natural resources are limited. Drylands are expected to expand under several scenarios of climatic change. However, relevant adaptation strategies need to account for the aridity level: it conditions the equilibrium tree-cover density, ranging from deserts (hyper-arid) to dense savannas (sub-humid). Here we focus on the evolution of climatically defined warm semi-arid areas, where low-tree density covers can be maintained. We study the global repartition of these regions in the future and the bioclimatic shifts involved. We adopted a bioclimatological approach based on the Köppen climate classification. The warm semi-arid class is characterized by mean annual temperatures over 18°C and a rainfall-limitation criterion. A multi-model ensemble of CMIP5 projections for three representative concentration pathways was selected to analyze future conditions. The classification was first applied to the start, middle and end of the 20th and 21st centuries, in order to localize past and future warm semi-arid regions. Then, time-series for the classification were built to characterize trends and variability in the evolution of those regions. According to the CRU datasets, global expansion of the warm semi-arid area has already started (~+13%), following the global warming trend since the 1900s. This will continue according to all projections, most significantly so outside the tropical belt. Under the "business as usual" scenario, the global warm semi-arid area will increase by 30% and expand 12° poleward in the Northern Hemisphere, according to the multi-model mean. Drying drives the conversion from equatorial sub-humid conditions. Beyond 30° of latitude, cold semi-arid conditions become warm semi-arid through warming, and temperate conditions through combined warming and drying processes. Those various transitions may have drastic but also very distinct ecological and sociological

  5. Aridity/humidity status of land surface in China during the last three decades

    Institute of Scientific and Technical Information of China (English)

    WU Shaohong; YIN Yunhe; ZHENG Du; YANG Qinye

    2005-01-01

    To clarify aridity/humidity status of land surface is helpful for studying environmental background and regional differences, seeking causes of environmental change, and providing a scientific basis for researches on climate change in the future. In this paper, the authors calculated potential evapotranspiration of China using data from 616 meteorological stations during the period of 1971-2000 with the Penman-Monteith model recommanded by FAO in 1998. Vysothkii's model was used to calculate aridity/humidity index. Then the calculated results of stations were interpolated to land surface using ArcGIS. Results show that the annual average potential evapotranspiration is 400-1500 mm in the whole country, 600-800 mm in most parts of it; and 350-1400 mm in growing season (April-Octobor), which is nearly 200 mm less than the annual average. According to the aridity/humidity indexes of 1.0, 1.5 and 4.0, the aridity/humidity status is categorized to four types, namely, humid, subhumid, semiarid and arid. A majority of stations (76%) are more humid in growing season than the annual average. Results of comprisons between the distribution map of aridity/humidity index with that of precipitation and vegetation indicate a good consistence of aridity/humidity status with natural environment. Therefore potential evapotranspiration calculated with modified FAO's Penman-Monteith model in combination with aridity/humidity index that considers water balance can more reasonably explain the actual land surface aridity/humidity status of China.

  6. Early Callovian ingression in southwestern Gondwana. Palaeoenvironmental evolution of the carbonate ramp (Calabozo Formation) in southwestern Mendoza, Neuquen basin, Argentina

    Science.gov (United States)

    Armella, Claudia; Cabaleri, Nora G.; Cagnoni, Mariana C.; Panarello, Héctor O.

    2013-08-01

    The carbonatic sequence of the Calabozo Formation (Lower Callovian) developed in southwestern Gondwana, within the northern area of the Neuquén basin, and is widespread in thin isolated outcrops in southwestern Mendoza province, Argentina. This paper describes the facies, microfacies and geochemical-isotopic analysis carried out in five studied localities, which allowed to define the paleoenvironmental conditions of a homoclinal shallow ramp model, highly influenced by sea level fluctuations, where outer, mid and inner ramp subenvironments were identified. The outer ramp subenvironment was only recognized in the south of the depocenter and is characterized by proximal outer ramp facies with shale levels and interbedded mudstone and packstone layers. The mid ramp subenvironment is formed by low energy facies (wackestone) affected by storms (packstones, grainstones and floatstones). The inner ramp subenvironment is the most predominant and is characterized by tidal flat facies (wackestones, packstones and grainstones) over which a complex of shoals (grainstones and packstones) dissected by tidal channels (packstone, grainstones and floatstones) developed. In the north area, protected environment facies were recorded (bioturbated wackestones and packstones). The vertical distribution of facies indicates that the paleoenvironmental evolution of the Calabozo Formation results from a highstand stage in the depocenter, culminating in a supratidal environment, with stromatolitic levels interbedded with anhydrite originated under restricted water circulation conditions due to a progressive isolation of the basin. δ13C and δ18O values of the carbonates of the Calabozo Formation suggest an isotopic signature influenced by local palaeoenvironmental parameters and diagenetic overprints. The δ13C and δ18O oscillations between the carbonates of the different studied sections are related with lateral facies variations within the carbonate ramp accompanied with dissimilar

  7. Seasonal fecundity and source-sink status of shrub-nesting birds in a southwestern riparian corridor

    Science.gov (United States)

    Brand, L.A.; Noon, B.R.

    2011-01-01

    Saltcedar (Tamarix spp.) has increasingly dominated riparian floodplains relative to native forests in the southwestern U.S., but little is known about its impacts on avian productivity or population status. We monitored 86 Arizona Bell's Vireo (Vireo bellii arizonae), 147 Abert's Towhee (Melozone aberti), and 154 Yellow-breasted Chat (Icteria virens) nests to assess reproductive parameters in cottonwood-willow (Populus-Salix), saltcedar, and mesquite (Prosopis spp.) stands along the San Pedro River, Arizona during 1999-2001. We also assessed source-sink status for each species in each vegetation type using field data combined with data from the literature. There were no significant differences in reproductive parameters between vegetation types for Abert's Towhee or Yellow-breasted Chat, although seasonal fecundity was quite low across vegetation types for the latter (0.75 ?? 0.14; mean ?? SE). Bell's Vireo had extremely low seasonal fecundity in saltcedar (0.10 ?? 0.09) and significantly fewer fledglings per nest in saltcedar (0.09 ?? 0.09) compared with cottonwood (1.07 ?? 0.32). Point estimates of ?? were substantially <1 for all three focal species in all habitats indicating the entire study area may be performing as a sink; 90% CI of included 1 only for Abert's Towhee across vegetation types and Bell's Vireo in cottonwood vegetation. These results are surprising given the San Pedro is considered to be one of the best remaining occurrences of lowland native riparian vegetation in the southwestern United States. ?? 2011 by the Wilson Ornithological Society.

  8. Arthropods in Natural Communities in Mescal Agave (Agave durangensis Gentry in an Arid Zone

    Directory of Open Access Journals (Sweden)

    Maria P. Gonzalez-Castillo

    2011-01-01

    Full Text Available Problem statement: The arthropods have a very important role in the arid zones due to their interactions with many organism and because they constituted an important element in the structure of the plant community. Nevertheless their importance there are few knowledge about the community of arthropods associated to vegetation in arid zones in the North of Mexico. The present study had the objective of determining the abundance, richness and diversity of arthropods in three localities where there are natural populations of mescal agave in the State of Durango, Mexico. Approach: In order to know the structure community of the arthropods associated to the mescal agave, we perform a sampling schedule during March 2008 to November 2010 by direct collection, using transects in three different localities with the presence of mescal agave. The relative abundance, species richness, Shannon’s diversity index, Pielou’s Index of evenness, Jaccard’s similitude and Simpson’s dominance indexes were determined. Results: A total of 4665 individual arthropods associated to mescal agave corresponding to 39 species were found. El Mezquital had the highest abundance and relative abundance (44.1% with 29 species. The mean species abundance was not significantly different between localities using Turkey’s test. The highest density per unit of area was found in El Mezquital (La Brena had the highest species diversity (1.89, evenness (0.61 and dominance (0.78. At the taxon level, Hymenoptera had the highest number of species represented (14, followed by Coleoptera (9 and hemiptera (5, with the remaining taxons with four, two and one species each. Conclusion: The greatest similitude was observed between La Brena and El Mezquital (46% which shared seven taxons, while the least similitude was observed between El Venado and La Brena (29%. Dominance/diversity curves are presented for each locality. The species Caulotops sp., Acutaspis agavis, Chilorus sp

  9. Should we plant trees to offset greenhouse gas emissions in semi-arid environments?

    Science.gov (United States)

    Pataki, D. E.; Pincetl, S.; Gillespie, T. W.; Li, W.; McCarthy, H. R.; Saatchi, S.; Saphores, J.

    2008-12-01

    Urban tree planting programs have been gaining popularity in the United States. Urban trees have been associated with a variety of environmental benefits, including improvements in air quality, mitigation of urban heat island effects, reductions in stormwater runoff, and more recently, carbon sequestration. There are also other potential aesthetic and economic benefits of urban forests, which have been shown to affect real estate values. However, there may also be significant economic and environmental costs of planting and maintaining trees in urban areas, particularly in semi-arid environments where trees are not native and require irrigation and fertilization. We are conducting an analysis of the Million Tree Initiative in the city of Los Angeles, which has committed to a major tree planting program. Los Angeles currently has a low tree canopy cover relative to other cities, particularly in its low income neighborhoods. We are evaluating the decision-making processes associated with the new tree planting program, its perceived benefits, and its actual benefits based on measurements of plant and ecosystem processes such as transpiration, photosynthesis, and water use efficiency; remote sensing analyses of tree cover and surface temperature; and economic analyses. We have found great variability in the interpretation of the program by its various participants, but also significant institutional learning as the program has evolved. Our datasets have challenged some of the common assumptions of the program, for example, the assumption that native species use less water than imported species and are therefore more environmentally beneficial in terms of water resources. We have also found significant impacts of the urban forest on air temperature, which may reduce energy use during the summer due to reductions in air conditioning. This is likely to be a larger effect of urban trees on greenhouse gas emissions than direct carbon sequestration alone, which is a very

  10. Antibody Reactivity of B Cells in Lupus Patients with Increased Disease Activity and ARID3a Expression

    Directory of Open Access Journals (Sweden)

    Julie M. Ward

    2015-11-01

    Full Text Available Earlier studies showed that the DNA-binding protein, Bright/ARID3a bound to a subset of human and mouse immunoglobulin heavy chain promoters where it enhanced expression. Indeed, mice with transgenic expression of ARID3a in all B lymphocytes have expanded MZ B cells and produce anti-nuclear antibodies (ANAs. Consistent with our findings in mice, we observed that human systemic lupus erythematosus (SLE patients had expanded numbers of peripheral blood ARID3a+ B cells that were associated with increased disease activity (p = 0.0038. We hypothesized that ARID3a+ naïve B cells would eventually produce autoantibodies, explaining associations between ARID3a expression and disease activity in lupus. Unlike healthy controls, ARID3a was expressed in the naïve B cell population in SLE patients, and we hypothesized that these might represent expansions of autoreactive cells. Therefore, monoclonal antibodies were generated from single-sorted naïve B cells derived from patients with normal (ARID3aN and high (ARID3aH numbers of ARID3a+ B cells. We found that ARID3a expression did not correlate with autoantibody expression. Furthermore, measures of antigen specificities of autoreactive antibodies did not reveal skewing toward particular proteins. These data suggest that the association of increased disease activity in SLE with numbers of ARID3a+ B lymphocytes may be mediated by an antibody-independent mechanism.

  11. Complex Proterozoic crustal assembly of southwestern North America in an arcuate subduction system:Tthe Black Canyon of the Gunnison, southwestern Colorado

    Science.gov (United States)

    Jessup, Micah J.; Kalstrom, Karl E.; Connelly, James; Williams, Michael; Livaccari, Richard; Tyson, Amanda; Rogers, Steven A.

    The dominant orogenic fabric in Proterozoic rocks of the southwestern U.S. includes a series of NE-striking shear zones that are commonly interpreted as suture zones across which blocks of juvenile crust were assembled to the southern margin of Laurentia. New structural and geochronological data from southwestern Colorado suggest that fabrics related to assembly of tectonostratigraphic terranes in this area strike northwest. The NW-striking foliations represent deformation at ca. 10-20 km paleodepths (ca. 1.77-1.71 Ga), and are parallel to magnetic anomalies and to gradients in mantle velocity structure. The agreement between these data sets suggests that the NW-striking structures are important at lithospheric scale, extend to >100 km depth, and may record assembly of southwestern Colorado across NW-striking tectonic boundaries. Geochronologic data indicate that northwest (central Colorado)—and northeast (Cheyenne belt)—striking boundaries developed simultaneously during accretion of southwestern Laurentia between ca. 1.78-1.73 Ga. We propose that the Yavapai province at ca. 1.75 Ga may have involved a complex arcuate subduction system, with multiple arcs, analogous to that of the modern Banda Sea, in the Indonesia region.

  12. Passive diffusion sampling of sulfur dioxide in India: Impact assessment on arid areas

    Institute of Scientific and Technical Information of China (English)

    S. Kumar; M. Mohan; R. Datta

    2002-01-01

    Environmental constraints have drastically limited options of sustainable developmentand have severely offset many developmental schemes. In this paper, possibilities of acidic depo-sition, as a counter measure of desertification, are analyzed. Seasonal data of ambient sulfur di-oxide, pH of rain water and soil acidity are collected for over an year and analyzed. Arid environ-ment of surrounding areas of Delhi is considered and analyzed. Though ambient sulfur depositionis well below critical level, it might not be truly indicative of plant survival in arid areas. Results maybe useful in arid area afforestation, and polluting industries relocation, which holds tremendouspotential vis-a-vis sustainable development.

  13. Validation of MODIS and Deep Blue aerosol optical depth retrievals in an arid/semi-arid region of northwest China

    Institute of Scientific and Technical Information of China (English)

    Xia Li; Xiangao Xia; Shengli Wang; Jietai Mao; Yan Liu

    2012-01-01

    The global aerosol optical depth (AOD or τ) has been retrieved using the Dark Target algorithm (the C004 and C005 products) and the Deep Blue algorithm (DB product).Few validations have thus far been performed in arid/semi-arid regions,especially in northwest China.The ground-based remote sensing of AOD from sun photometers at four sites in Xinjiang during the years 2002-2003 is used to validate aerosol products,including C004,C005 and DB of the Moderate Resolution Imaging Spectroradiometer (MODIS).The results show substantial improvement in the C005 aerosol product over the C004 product.The average correlation coefficient of regression with ground measurements increased from 0.59 to 0.69,and the average offset decreased from 0.28 to 0.13.The slopes of the linear regressions tended to be close to unity.The percentage of AODs falling within the retrieval errors of 30% (or △τ =±0.1 ± 0.2τ)increased from 16.1% to 45.6%.The best retrievals are obtained over an oasis region,whereas the worst are obtained over urban areas.Both the MODIS C004 and C005 products overestimate AOD,which is likely related to improper assumptions of the aerosol model and of the estimation of surface reflectance.An encouraging result has been derived with regard to validation of the DB AOD.Overall,the average offset,slope and correlation coefficient of regression with sun-photometer measurements are -0.04,0.88 and 0.85,respectively.Approximately 73% of the DB AOD retrievals fall within the expected error of 30%.Underestimation of the AOD by the DB products is observed.The aerosol model and estimations of surface reflectance in this region require further improvements.

  14. Plant species diversity of wetland ecosystem in an arid and semi-arid region in northwest China

    Institute of Scientific and Technical Information of China (English)

    LI Rui; LIU Yunfang; ZHANG Kebin

    2007-01-01

    In order to study the changes of plant species diversity along the biotope gradient and its influencing factors in a wetland-add grassland ecosystem in the add and semi-arid regions of northwest China,four transect lines were set along the biotope gradient in four directions:east,northeast,west and northwest,and altogether 123 sample plots were investigated on species composition,density,foliage cover,height and biomass (calculated in fresh weight).The whole study area was divided into the Wetland zone,the ecotone and the arid grassland zone in terms of habitat characteristics and vegetation types.In this paper,we analyzed and compared the species diversity in the ecotone of a wetland-dry grassland ecosystem in Yanchi County,Ningxia Hui Autonomous Region,with the help of biodiversity software BioDiversity Pro and statistical software Microcal Origin,as well as the combined measurement of species diversity indices.The results revealed distinct differences between those three vegetation zones along each transect line.The ecotone had the highest richness indices (R) and comprehensive diversity indices (Y),reflecting the edge effect.The greatest evenness indices (E) were found in the add grassland zones.This result agreed with the phenomenon of desertification reversion,vegetation restoration and dominant communities' formation.As for the four transect lines,the east and the northeast scored higher in each diversity index than the others due to less human disturbance,gentler topography uplift and more intercepted materials and energies.The highest Simpson index value was found in the northeast transect line,which was 39.9% higher than the lowest in the Northwest.

  15. Changes of AM fungal abundance along environmental gradients in the arid and semi-arid grasslands of northern China.

    Directory of Open Access Journals (Sweden)

    Yajun Hu

    Full Text Available Arbuscular mycorrhizal (AM fungi are ubiquitous symbionts of higher plants in terrestrial ecosystems, while the occurrence of the AM symbiosis is influenced by a complex set of abiotic and biotic factors. To reveal the regional distribution pattern of AM fungi as driven by multiple environmental factors, and to understand the ecological importance of AM fungi in natural ecosystems, we conducted a field investigation on AM fungal abundance along environmental gradients in the arid and semi-arid grasslands of northern China. In addition to plant parameters recorded in situ, soil samples were collected, and soil chemo-physical and biological parameters were measured in the lab. Statistical analyses were performed to reveal the relative contribution of climatic, edaphic and vegetation factors to AM fungal abundance, especially for extraradical hyphal length density (HLD in the soil. The results indicated that HLD were positively correlated with mean annual temperature (MAT, soil clay content and soil pH, but negatively correlated with both soil organic carbon (SOC and soil available N. The multiple regressions and structural equation model showed that MAT was the key positive contributor and soil fertility was the key negative contributor to HLD. Furthermore, both the intraradical AM colonization (IMC and relative abundance of AM fungi, which was quantified by real-time PCR assay, tended to decrease along the increasing SOC content. With regard to the obvious negative correlation between MAT and SOC in the research area, the positive correlation between MAT and HLD implied that AM fungi could potentially mitigate soil carbon losses especially in infertile soils under global warming. However, direct evidence from long-term experiments is still expected to support the AM fungal contribution to soil carbon pools.

  16. Changes of AM fungal abundance along environmental gradients in the arid and semi-arid grasslands of northern China.

    Science.gov (United States)

    Hu, Yajun; Rillig, Matthias C; Xiang, Dan; Hao, Zhipeng; Chen, Baodong

    2013-01-01

    Arbuscular mycorrhizal (AM) fungi are ubiquitous symbionts of higher plants in terrestrial ecosystems, while the occurrence of the AM symbiosis is influenced by a complex set of abiotic and biotic factors. To reveal the regional distribution pattern of AM fungi as driven by multiple environmental factors, and to understand the ecological importance of AM fungi in natural ecosystems, we conducted a field investigation on AM fungal abundance along environmental gradients in the arid and semi-arid grasslands of northern China. In addition to plant parameters recorded in situ, soil samples were collected, and soil chemo-physical and biological parameters were measured in the lab. Statistical analyses were performed to reveal the relative contribution of climatic, edaphic and vegetation factors to AM fungal abundance, especially for extraradical hyphal length density (HLD) in the soil. The results indicated that HLD were positively correlated with mean annual temperature (MAT), soil clay content and soil pH, but negatively correlated with both soil organic carbon (SOC) and soil available N. The multiple regressions and structural equation model showed that MAT was the key positive contributor and soil fertility was the key negative contributor to HLD. Furthermore, both the intraradical AM colonization (IMC) and relative abundance of AM fungi, which was quantified by real-time PCR assay, tended to decrease along the increasing SOC content. With regard to the obvious negative correlation between MAT and SOC in the research area, the positive correlation between MAT and HLD implied that AM fungi could potentially mitigate soil carbon losses especially in infertile soils under global warming. However, direct evidence from long-term experiments is still expected to support the AM fungal contribution to soil carbon pools.

  17. COMPOSITIONAL AND PETROGENETIC FEATURES OF SCHISTOSE ROCKS OF IBADAN AREA, SOUTHWESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Oluwatoke O.O.

    2009-12-01

    Full Text Available Amphibole and quartz schist which occur in association with migmatite gneiss, granitic gneiss and Pan African Older Granitebodies around Ibadan area, southwestern Nigeria, were studied with a view to elucidate their compositional characteristics andtheir evolution.Mineralogical determinations from optical studies show a high proportion of granular quartz and accessory muscovite in thequartz schist. The amphibole schist on the other hand comprises mainly dark colored bands of hornblende with subordinate tremolite, chlorite and minor amounts of plagioclase and quartz. 
    Chemical analysis of the samples obtained by Inductively Coupled Plasma Mass Spectrometry (ICPMS instrumentation method, involving major and trace elements reveal the silicieous nature of the quartz schist and and the amphibole .samples of both rock units are also marked by relatively elevated contents of Ba, Zr, Rb, La and Ce and Zr. In addition, variation plots using Na2O, Al2O,K2Osuggests arenaceous sedimentary ancestry for the quartz schist and an igneous ancestry most probablymafic extrusive volcanics for the amphibole schist. Provenance indicators, such as Ba, in the quartz schists suggest derivation of this sedimentary protolith from the weathering of largely granitic rocks. Similarity of the amphibole schist progenitors with subalkaline basaltic andesite is also implied by the Na2O+K2O versus SiO2 bivariate plot, whilethe Na2O+K2O-Fe2O3 (t-MgO ternary plot reveal their calc-alkaline affinity. Tectonically, the quartz schists evolved within the passive margin environment, whereas the MgO-Fe2O3-Al2O3 ternary plots reveal an Ocean island basalt tectonic evolution for the amphibole schist.

  18. Managing Carbon on Federal Public Lands: Opportunities and Challenges in Southwestern Colorado

    Science.gov (United States)

    Dilling, Lisa; Kelsey, Katharine C.; Fernandez, Daniel P.; Huang, Yin D.; Milford, Jana B.; Neff, Jason C.

    2016-08-01

    Federal lands in the United States have been identified as important areas where forests could be managed to enhance carbon storage and help mitigate climate change. However, there has been little work examining the context for decision making for carbon in a multiple-use public land environment, and how science can support decision making. This case study of the San Juan National Forest and the Bureau of Land Management Tres Rios Field Office in southwestern Colorado examines whether land managers in these offices have adequate tools, information, and management flexibility to practice effective carbon stewardship. To understand how carbon was distributed on the management landscape we added a newly developed carbon map for the SJNF-TRFO area based on Landsat TM texture information (Kelsey and Neff in Remote Sens 6:6407-6422. doi: 10.3390/rs6076407, 2014). We estimate that only about 22 % of the aboveground carbon in the SJNF-TRFO is in areas designated for active management, whereas about 38 % is in areas with limited management opportunities, and 29 % is in areas where natural processes should dominate. To project the effects of forest management actions on carbon storage, staff of the SJNF are expected to use the Forest Vegetation Simulator (FVS) and extensions. While identifying FVS as the best tool generally available for this purpose, the users and developers we interviewed highlighted the limitations of applying an empirically based model over long time horizons. Future research to improve information on carbon storage should focus on locations and types of vegetation where carbon management is feasible and aligns with other management priorities.

  19. Incidence of retinopathy of prematurity and risk factors in the South-Western Region of Iran

    Directory of Open Access Journals (Sweden)

    Mostafa Feghhi

    2012-01-01

    Full Text Available Aims: The aim of this study was to report the incidence of retinopathy of prematurity (ROP and the contribution of various risk factors to ROP in the south-western region of Iran. Material and Methods: This cross-sectional case-control series reviewed all low birth weight (LBW, ≤2000 g neonates and/or neonates less than 32 weeks gestational age who had been hospitalized in the Neonatal Intensive Care Unit from 2006 to 2010. The cohort was divided into infants without ROP (nonROP group and infants with ROP (ROP group. Infants were first examined by a group of pediatric ophthalmologists 6 weeks after delivery, and then were followed every 1-2 weeks until death, discharge or complete retinal avascularization. If an infant developed ROP, further examinations were performed based on the Early Treatment for Retinopathy of Prematurity Study protocol. Demographic data, medical treatment, and ophthalmic disorders were all statistically analyzed. Results: A total of 576 infants met the criteria for evaluation. Of 576 total patients, 183 infants (32% (88 males, 95 females had ROP. There were significant differences between groups in gestational age, body weight, and duration of oxygen administration, and sepsis (P<0.05. Male/female ratio, single and multiple births, and jaundice, phototherapy, and blood transfusion were not significant. The majority of ROP was stage I or II (137, 74.8%. Stage III or greater developed in 46 infants (25.1% [Note: The ocular history and ocular outcomes are not risk factors.] Conclusions: The incidence of ROP in this study is higher than that in other parts of the world. Awareness and knowledge of ROP and its relative risks need to be reinforced in ophthalmologists and other health practitioners.

  20. Human infrastructure and invasive plant occurrence across rangelands of southwestern Wyoming, U.S.A.

    Science.gov (United States)

    Manier, Daniel J.; Aldridge, Cameron L.; O'Donnell, Michael S.; Schell, Spencer

    2014-01-01

    Although human influence across rural landscapes is often discussed, interactions between the native, natural systems and human activities are challenging to measure explicitly. We assessed the distribution of introduced, invasive species as related to anthropogenic infrastructure and environmental conditions across southwestern Wyoming. to discern direct correlations as well as covariate influences between land use, land cover, and abundance of invasive plants, and assess the supposition that these features affect surrounding rangeland conditions. Our sample units were 1 000 m long and extended outward from target features, which included roads, oil and gas well pads, pipelines, power lines, and featureless background sites. Sample sites were distributed across the region using a stratified, random design with a frame that represented features and land-use intensity. In addition to land-use gradients, we captured a representative, but limited, range of variability in climate, soils, geology, topography, and dominant vegetation. Several of these variables proved significant, in conjunction with distance from anthropogenic features, in regression models of invasive plant abundance. We used general linear models to demonstrate and compare associations between invasive plant frequency and Euclidian distance from features, natural logarithm transformed distances (log-linear), and environmental variables which were presented as potential covariates. We expected a steep curvilinear (log or exponential) decline trending towards an asymptote along the axis representing high abundance near features with rapid decrease beyond approximately 50–100 m. Some of the associations we document exhibit this pattern, but we also found some invasive plant distributions that extended beyond our expectations, suggesting a broader distribution than anticipated. Our results provide details that can inform local efforts for management and control of invasive species, and they provide

  1. Forearc structure beneath southwestern British Columbia: A three-dimensional tomographic velocity model

    Science.gov (United States)

    Ramachandran, K.; Dosso, S.E.; Spence, G.D.; Hyndman, R.D.; Brocher, T.M.

    2005-01-01

    This paper presents a three-dimensional compressional wave velocity model of the forearc crust and upper mantle and the subducting Juan de Fuca plate beneath southwestern British Columbia and the adjoining straits of Georgia and Juan de Fuca. The velocity model was constructed through joint tomographic inversion of 50,000 first-arrival times from earthquakes and active seismic sources. Wrangellia rocks of the accreted Paleozoic and Mesozoic island arc assemblage underlying southern Vancouver Island in the Cascadia forearc are imaged at some locations with higher than average lower crustal velocities of 6.5-7.2 km/s, similar to observations at other island arc terranes. The mafic Eocene Crescent terrane, thrust landward beneath southern Vancouver Island, exhibits crustal velocities in the range of 6.0-6.7 km/s and is inferred to extend to a depth of more than 20 km. The Cenozoic Olympic Subduction Complex, an accretionary prism thrust beneath the Crescent terrane in the Olympic Peninsula, is imaged as a low-velocity wedge to depths of at least 20 km. Three zones with velocities of 7.0-7.5 km/s, inferred to be mafic and/or ultramafic units, lie above the subducting Juan de Fuca plate at depths of 25-35 km. The forearc upper mantle wedge beneath southeastern Vancouver Island and the Strait of Georgia exhibits low velocities of 7.2-7.5 km/s, inferred to correspond to ???20% serpentinization of mantle peridotites, and consistent with similar observations in other warm subduction zones. Estimated dip of the Juan de Fuca plate beneath southern Vancouver Island is ???11??, 16??, and 27?? at depths of 30, 40, and 50 km, respectively. Copyright 2005 by the American Geophysical Union.

  2. Managing Carbon on Federal Public Lands: Opportunities and Challenges in Southwestern Colorado.

    Science.gov (United States)

    Dilling, Lisa; Kelsey, Katharine C; Fernandez, Daniel P; Huang, Yin D; Milford, Jana B; Neff, Jason C

    2016-08-01

    Federal lands in the United States have been identified as important areas where forests could be managed to enhance carbon storage and help mitigate climate change. However, there has been little work examining the context for decision making for carbon in a multiple-use public land environment, and how science can support decision making. This case study of the San Juan National Forest and the Bureau of Land Management Tres Rios Field Office in southwestern Colorado examines whether land managers in these offices have adequate tools, information, and management flexibility to practice effective carbon stewardship. To understand how carbon was distributed on the management landscape we added a newly developed carbon map for the SJNF-TRFO area based on Landsat TM texture information (Kelsey and Neff in Remote Sens 6:6407-6422. doi: 10.3390/rs6076407 , 2014). We estimate that only about 22 % of the aboveground carbon in the SJNF-TRFO is in areas designated for active management, whereas about 38 % is in areas with limited management opportunities, and 29 % is in areas where natural processes should dominate. To project the effects of forest management actions on carbon storage, staff of the SJNF are expected to use the Forest Vegetation Simulator (FVS) and extensions. While identifying FVS as the best tool generally available for this purpose, the users and developers we interviewed highlighted the limitations of applying an empirically based model over long time horizons. Future research to improve information on carbon storage should focus on locations and types of vegetation where carbon management is feasible and aligns with other management priorities. PMID:27272016

  3. Variation in functional rooting depth and soil water partitioning along an elevational gradient in the southwestern U.S

    Science.gov (United States)

    Guo, J.; Hungate, B. A.; Kolb, T.; KOCH, G. W.

    2012-12-01

    In semi-arid environments, co-existing plant species may vary in rooting depth, reflecting functional differences in water sources. In mountains of the southwestern U.S., moisture availability increases with elevation and winter and summer precipitation inputs differ isotopically. Examining variation in functional rooting depth among different plant communities and seasons is important to understanding how these communities may respond to the predicted warming and drying of the Southwest. The goal of this study was to assess the water partitioning of the woody plant community along an elevational moisture gradient using water isotopes as a proxy for rooting depth. We hypothesized that spatial and temporal water partitioning would be greatest in low elevation, moisture-stressed sites and would decrease as moisture availability increases with elevation. Five plots were established in each of five biotic communities: upland Sonoran desert, pinyon-juniper woodland, ponderosa pine forest, mixed-conifer forest, and spruce-fir forest. Soils (surface, 20 cm, 40 cm) and stem samples of dominant woody perennials were sampled during the late spring dry season and in late summer following monsoon rains, water was extracted using a cryo-vacuum line, and δD and δ18O values were determined by off-axis cavity ringdown spectroscopy. Soil moisture content increased with elevation across all sites and increased with soil depth in the desert, pinyon-juniper, and ponderosa sites. The δD values differed significantly among species in the desert and the ponderosa forest communities (p=0.014 and 0.039 ), while no species differences in δD were found in the pinyon-juniper woodland or mixed-conifer forest. With the exception of the pinyon-juniper woodland, these data support our hypothesis that niche differentiation between species becomes less significant higher on the topographic moisture gradient, in the mixed-conifer forest. While spatial water partitioning mostly follows our

  4. Post-Gondwana geomorphic evolution of southwestern Africa: Implications for hte controls on landscape development from observations and numerical experiments

    Science.gov (United States)

    Gilchrist, Alan R.; Kooi, Henk; Beaumont, Christopher

    1994-01-01

    The relationship between morphology and surficial geology is used to quantify the denudation that has occurred across southwestern Africa sicne the fragmentation of Gondwana during the Early Mesozoic. Two main points emerge. Signficant denudation, of the order of kilometers, is widespread except in the Kalahari region of the continental interior. The denudation is systematically distributed so that the continental exterior catchment, draining directly to the Cape basin, is denuded to a greater depth than the interior catchment inland of the Great Escarpment. The analysis also implies tha the majority of the denudation occurred before the beginning of the Cenozoic for both teh exerior and interior catchments. Existing models of landscape development are reviewed, and implications of the denudation chronology are incorporated into a revised conceptual model. This revision implies tha thte primary effect of rifting on the subsequent landscape evolution is that it generates two distinct drainage regimes. A marginal upwarp, or rift flank uplift, separates rejuvenated rivers that drain into the subsiding rift from rivers in the continetal interior that are deflected but not rejuvenated. The two catchments evolve independently unless they are integrated by breaching of hte marginal upwarp. If this occurs, the exterior baselevel is communicated to the interior catchment that is denuded accordingly. Denudation rates generally decrease as the margin evolves, and this decrease is reinforced by the exposure of substrate that is resistant to denudation and/or a change to a more arid climate. The observations do not reveal a particular style of smaller-scale landscape evolution, sucha s escarpment retreat, that is responsible for the differential denudation across the region. It is proposed that numerical model experiments, which reflect the observational insights at the large scale, may identify the smaller-scale controls on escarpment development if the model and natural

  5. Post-Gondwana geomorphic evolution of southwestern Africa: Implications for hte controls on landscape development from observations and numerical experiments

    Science.gov (United States)

    Gilchrist, Alan R.; Kooi, Henk; Beaumont, Christopher

    1994-06-01

    The relationship between morphology and surficial geology is used to quantify the denudation that has occurred across southwestern Africa sicne the fragmentation of Gondwana during the Early Mesozoic. Two main points emerge. Signficant denudation, of the order of kilometers, is widespread except in the Kalahari region of the continental interior. The denudation is systematically distributed so that the continental exterior catchment, draining directly to the Cape basin, is denuded to a greater depth than the interior catchment inland of the Great Escarpment. The analysis also implies tha the majority of the denudation occurred before the beginning of the Cenozoic for both teh exerior and interior catchments. Existing models of landscape development are reviewed, and implications of the denudation chronology are incorporated into a revised conceptual model. This revision implies tha thte primary effect of rifting on the subsequent landscape evolution is that it generates two distinct drainage regimes. A marginal upwarp, or rift flank uplift, separates rejuvenated rivers that drain into the subsiding rift from rivers in the continetal interior that are deflected but not rejuvenated. The two catchments evolve independently unless they are integrated by breaching of hte marginal upwarp. If this occurs, the exterior baselevel is communicated to the interior catchment that is denuded accordingly. Denudation rates generally decrease as the margin evolves, and this decrease is reinforced by the exposure of substrate that is resistant to denudation and/or a change to a more arid climate. The observations do not reveal a particular style of smaller-scale landscape evolution, sucha s escarpment retreat, that is responsible for the differential denudation across the region. It is proposed that numerical model experiments, which reflect the observational insights at the large scale, may identify the smaller-scale controls on escarpment development if the model and natural

  6. Integrating management objectives and grazing strategies on semi-arid rangelands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Rangelands account for almost half of Nebraska's 24 million acres. Much of these expansive natural resource areas are in the semi-arid climatic region of Nebraska...

  7. Karst characterization in a semi-arid region using gravity, seismic, and resistivity geophysical techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Barnhart, Kevin Scott

    2013-10-01

    We proposed to customize emerging in situ geophysical monitoring technology to generate time-series data during sporadic rain events in a semi-arid region. Electrodes were to be connected to wireless \

  8. Human Constraints to Sustainable Agriculture in the Arid Regions of South Africa.

    Science.gov (United States)

    Duvel, G. H.; Botha, A. J.

    1999-01-01

    Interviews with 79 South African farmers in arid regions showed that their conservation practices were influenced by such human factors as needs, perceptions, and knowledge. Direct influence on adoption behaviors was recommended to encourage sustainable agriculture practices. (SK)

  9. Preliminary evaluation of selected in situ remediation technologies for Volatile Organic Compound contamination at Arid sites

    Energy Technology Data Exchange (ETDEWEB)

    Lenhard, R.J.; Gerber, M.A.; Amonette, J.E.

    1992-10-01

    To support the Volatile Organic Compounds-Arid Site (VOC-Arid) Integrated Demonstration (ID) in its technical, logistical, institutional, and economical testing of emerging environmental management and restoration technologies. Pacific Northwest Laboratory(a) is evaluating several in situ remediation technologies for possible inclusion in the demonstration. The evaluations are made with respect to the initial focus of the VOC-Arid ID: the carbon tetrachloride contamination at the Hanford Site, where it was disposed to the vadose zone along with other volatile and nonvolatile organic wastes. heavy metals, acids. and radionuclides. The purposes of this report are (1) to identify candidate in situ technologies for inclusion in the program, (2) to evaluate the candidate technologies based on their potential applicability to VOC contamination at arid sites and geologic conditions representative of the ID host site (i.e., Hanford Site), and (3) to prioritize those technologies for future US Department of Energy (DOE) support.

  10. A brief introduction to Physical Geography of Arid Land in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A book, Physical Geography of Arid Land in China, mainly edited by Prof. Xi CHEN from Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences has been published by Science Press in July of 2010.

  11. Energy and water budgets of larks in a life history perspective : Parental effort varies with aridity

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Visser, GH

    2004-01-01

    We compared physiological, demographic, and ecological variables of larks to gain insights into life history variation along an aridity gradient, incorporating phylogenetic relationships in analyses when appropriate. Quantifying field metabolic rate (FMR). and water influx rate (WIR) of parents feed

  12. Characteristics and laws of MODS coupling relation in arid zone under global change

    Institute of Scientific and Technical Information of China (English)

    WANG Ranghui; ZHANG Huizhi; HUANG Qing

    2006-01-01

    Global change has influenced the distribution pattern and spatio-temporal changes of resources in arid zone, and has restrained the land use and land cover change, which is shown by water-heat state, landscape structure, climate effect, and human activities. The above-mentioned characteristics have a close coupling relation with the mountain-oasisdesert system (MODS). The climate in Central Asia arid zone is warm and wet, which is different from that in northern China which takes a tendency of aridity, and the mechanism has restricted the characteristics and laws of MODS. Systematic interface characteristics and process, especially the formation,transformation and consumption laws of water resource reflect directly MODS's response to global change in arid zone. Spatio-temporal pattern, dynamic change, scale change and coupling mode of MODS reflect the ecology mechanism between the systems and within the systems.

  13. The 2010 spring drought reduced primary productivity in southwestern China

    International Nuclear Information System (INIS)

    Many parts of the world experience frequent and severe droughts. Summer drought can significantly reduce primary productivity and carbon sequestration capacity. The impacts of spring droughts, however, have received much less attention. A severe and sustained spring drought occurred in southwestern China in 2010. Here we examine the influence of this spring drought on the primary productivity of terrestrial ecosystems using data on climate, vegetation greenness and productivity. We first assess the spatial extent, duration and severity of the drought using precipitation data and the Palmer drought severity index. We then examine the impacts of the drought on terrestrial ecosystems using satellite data for the period 2000–2010. Our results show that the spring drought substantially reduced the enhanced vegetation index (EVI) and gross primary productivity (GPP) during spring 2010 (March–May). Both EVI and GPP also substantially declined in the summer and did not fully recover from the drought stress until August. The drought reduced regional annual GPP and net primary productivity (NPP) in 2010 by 65 and 46 Tg C yr−1, respectively. Both annual GPP and NPP in 2010 were the lowest over the period 2000–2010. The negative effects of the drought on annual primary productivity were partly offset by the remarkably high productivity in August and September caused by the exceptionally wet conditions in late summer and early fall and the farming practices adopted to mitigate drought effects. Our results show that, like summer droughts, spring droughts can also have significant impacts on vegetation productivity and terrestrial carbon cycling. (letter)

  14. Resilience of southwestern Amazon forests to anthropogenic edge effects.

    Science.gov (United States)

    Phillips, Oliver L; Rose, Sam; Mendoza, Abel Monteagudo; Vargas, Percy Núñez

    2006-12-01

    Anthropogenic edge effects can compromise the conservation value of mature tropical forests. To date most edge-effect research in Amazonia has concentrated on forests in relatively seasonal locations or with poor soils in the east of the basin. We present the first evaluation from the relatively richer soils of far western Amazonia on the extent to which mature forest biomass, diversity, and composition are affected by edges. In a southwestern Amazonian landscape we surveyed woody plant diversity, species composition, and biomass in 88x0.1 ha samples of unflooded forest that spanned a wide range in soil properties and included samples as close as 50 m and as distant as >10 km from anthropogenic edges. We applied Mantel tests, multiple regression on distance matrices, and other multivariate techniques to identify anthropogenic effects before and after accounting for soil factors and spatial autocorrelation. The distance to the nearest edge, access point, and the geographical center of the nearest community ("anthropogenic-distance effects") all had no detectable effect on tree biomass or species diversity. Anthropogenic-distance effects on tree species composition were also below the limits of detection and were negligible in comparison with natural environmental and spatial factors. Analysis of the data set's capacity to detect anthropogenic effects confirmed that the forests were not severely affected by edges, although because our study had few plots within 100 m of forest edges, our confidence in patterns in the immediate vicinity of edges is limited. It therefore appears that the conservation value of most "edge" forests in this region has not yet been compromised substantially. We caution that because this is one case study it should not be overinterpreted, but one explanation for our findings may be that western Amazonian tree species are naturally faster growing and more disturbance adapted than those farther east.

  15. Evaluation of elemental enrichments in surface sediments off southwestern Taiwan

    Science.gov (United States)

    Chen, Chen-Tung; Kandasamy, Selvaraj

    2008-05-01

    Surface slices of 20 sediment cores, off southwestern Taiwan, and bed sediment of River Kaoping were measured for major and trace elements (Al, As, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Ti, V, and Zn) to evaluate the geochemical processes responsible for their distribution, including elemental contamination. Major element/Al ratio and mean grain size indicate quartz-dominated, coarse grained sediments that likely derived from sedimentary rocks of Taiwan and upper crust of Yangtze Craton. Bi-plot of SiO2 versus Fe2O{3/T} suggests the possible iron enrichment in sediments of slag dumping sites. Highest concentrations of Cr, Mn, P, S, and Zn found in sediments of dumping sites support this. Correlation analysis shows dual associations, detrital and organic carbon, for Cr, P, S, and V with the latter association typical for sediments in dumping sites. Normalization of trace elements to Al indicates high enrichment factors (>2) for As, Cd, Pb, and Zn, revealing contamination. Factor analysis extracted four geochemical associations with the principal factor accounted for 25.1% of the total variance and identifies the combined effects of dumped iron and steel slag-induced C-S-Fe relationship owing to authigenic precipitation of Fe-Mn oxyhydroxides and/or metal sulfides, and organic matter complexation of Fe, Mn, Ca, Cr, P, and V. Factors 2, 3, and 4 reveal detrital association (Ti, Al, Ni, Pb, Cu, and V), effect of sea salt (Cl, Mg, Na, and K) and anthropogenic component (As and Zn)-carbonate link, respectively, in the investigated sediments.

  16. A new species of Enyalioides (Iguanidae: Hoplocercinae from southwestern Ecuador

    Directory of Open Access Journals (Sweden)

    Omar Torres-Carvajal

    2008-01-01

    Full Text Available We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This represents the third species in the genus known to occur west of the Andes in South America; the other two species are E. heterolepis and E. oshaughnessyi. Among other characters, the new species can be distinguished from other members in the genus by having small, keeled, paravertebrals; a series of skin folds on the lateral aspects of body and neck; size-homogeneous scales on body and limbs; distinct caudal segments; and an extensive dark patch on the gular region of adult males. Morphological similarity suggests that the new species, which we call E. touzeti, is closely related to E. oshaughnessyi.Describimos una especie nueva de Enyalioides del bosque nublado al suroccidente de Ecuador. Esta representa la tercera especie de este género que habita al occidente de los Andes en América del Sur; las otras dos especies occidentales son E. heterolepis y E. oshaughnessyi. La especie nueva se diferencia de otras especies del género por tener, entre otras características, paravertebrales pequeñas y quilladas, pliegues dermales a los lados del cuello y cuerpo, escamas homogéneas en el cuerpo y extremidades, segmentos caudales visibles, y un parche oscuro que cubre gran parte de la región gular en machos. Semejanzas morfológicas sugieren que la especie nueva, a la cual llamamos E. touzeti, está cercanamente relacionada con E. oshaughnessyi.

  17. "Actionable" Climate Scenarios for Natural Resource Managers in Southwestern Colorado

    Science.gov (United States)

    Rangwala, I.; Rondeau, R.; Wyborn, C.

    2014-12-01

    Locally relevant projections of climate change provide critical insights for natural resource managers seeking to adapt their management activities to climate change. To provide such information, we developed narrative scenarios of future climate change and its impacts on different ecosystems in southwestern Colorado. This multi-institution and trans-disciplinary project seeks to provide useful and useable knowledge to facilitate climate change adaptation in the context of uncertainty. The narratives are intended to provide detailed insights into the range of changes that natural resource managers may face in the future. These scenarios were developed in an iterative process through interactions between ecologists, social and climate scientists. In our scenario development process, climate uncertainty is acknowledged by having multiple scenarios, where each scenario is regarded as a storyline with equal probability as another scenario. Rather than a qualitative narration of the general direction of change and range in responses, we quantified changes in several decision relevant climate and ecological responses based on our best available understanding and provided a tight storyline for each scenario to facilitate (a) a more augmented use of scientific information in a decision-making process, (b) differential responses from stakeholders across the different scenarios, and (c) identification of strategies that could work across these multiple scenarios. This presentation will discuss the process of selecting the scenarios, quantifying climate and ecological responses, and the criteria for building the narrative for each scenario. We will also cover the process by which these scenarios get used, and how the user feedbacks are integrated in further developing the tools and processes.

  18. A Methodology to Assess and Evaluate Rainwater Harvesting Techniques in (Semi-) Arid Regions

    OpenAIRE

    Ammar Adham; Michel Riksen; Mohamed Ouessar; Coen J Ritsema

    2016-01-01

    Arid and semi-arid regions around the world face water scarcity problems due to lack of precipitation and unpredictable rainfall patterns. For thousands of years, rainwater harvesting (RWH) techniques have been applied to cope with water scarcity. Researchers have used many different methodologies for determining suitable sites and techniques for RWH. However, limited attention has been given to the evaluation of RWH structure performance. The aim of this research was to design a scientifical...

  19. Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations

    OpenAIRE

    Camacho Suarez, V. V.; Saraiva Okello, A. M. L.; Wenninger, J.W.; Uhlenbrook, S.

    2015-01-01

    The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs may increase the complexity of hydrological process dyna...

  20. Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations

    OpenAIRE

    V. V. Camacho; Saraiva Okello, A. M. L.; Wenninger, J.W.; Uhlenbrook, S.

    2015-01-01

    The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs increase the complexity of hydrologica...

  1. REUSE OF TREATED WASTEWATER IN AGRICULTURE: SOLVING WATER DEFICIT PROBLEMS IN ARID AREAS (REVIEW)

    OpenAIRE

    Faissal AZIZ; Farissi, Mohamed

    2014-01-01

    In the arid and semiarid areas, the availability and the management of irrigation water have become priorities of great importance. The successive years of drought, induced by climate change and population growth, increasingly reduced the amount of water reserved for agriculture. Consequently, many countries have included wastewater reuse as an important dimension of water resources planning. In the more arid areas wastewater is used in agriculture, releasing high resource of water supplies. ...

  2. Impact of grazing on range plant community components under arid Mediterranean climate in northern Syria

    OpenAIRE

    Niane, A.A.

    2013-01-01

    Keywords: Rotational grazing, full protection, continuous grazing species richness, species diversity, soil seed bank, Bayesian methods, Salsola vermiculata, seed longevity, rangeland management, Syria.   Rangelands represent 70% of the semi-arid and arid Mediterranean land mass. It is a natural habitat for millions of people whose livelihood depends on animal husbandry. The revolutionary developments in the animal husbandry and veterinary medicines resulted in exponential increases in h...

  3. Geochemical Weathering Increases Lead Bioaccessibility in Semi-Arid Mine Tailings

    OpenAIRE

    Hayes, Sarah M.; Webb, Sam M.; Bargar, John R.; O'Day, Peggy A; Maier, Raina M.; Chorover, Jon

    2012-01-01

    Mine tailings can host elevated concentrations of toxic metal(loid)s that represent a significant hazard to surrounding communities and ecosystems. Eolian transport, capable of translocating small (micrometer-sized) particles, can be the dominant mechanism of toxic metal dispersion in arid or semi-arid landscapes. Human exposure to metals can then occur via direct inhalation or ingestion of particulates. The fact that measured doses of total lead (Pb) in geomedia correlate poorly with blood P...

  4. Assessing deep-seated landslide susceptibility using 3-D groundwater and slope-stability analyses, southwestern Seattle, Washington

    Science.gov (United States)

    Brien, Dianne L.; Reid, Mark E.

    2008-01-01

    In Seattle, Washington, deep-seated landslides on bluffs along Puget Sound have historically caused extensive damage to land and structures. These large failures are controlled by three-dimensional (3-D) variations in strength and pore-water pressures. We assess the slope stability of part of southwestern Seattle using a 3-D limit-equilibrium analysis coupled with a 3-D groundwater flow model. Our analyses use a high-resolution digital elevation model (DEM) combined with assignment of strength and hydraulic properties based on geologic units. The hydrogeology of the Seattle area consists of a layer of permeable glacial outwash sand that overlies less permeable glacial lacustrine silty clay. Using a 3-D groundwater model, MODFLOW-2000, we simulate a water table above the less permeable units and calibrate the model to observed conditions. The simulated pore-pressure distribution is then used in a 3-D slope-stability analysis, SCOOPS, to quantify the stability of the coastal bluffs. For wet winter conditions, our analyses predict that the least stable areas are steep hillslopes above Puget Sound, where pore pressures are elevated in the outwash sand. Groundwater flow converges in coastal reentrants, resulting in elevated pore pressures and destabilization of slopes. Regions predicted to be least stable include the areas in or adjacent to three mapped historically active deep-seated landslides. The results of our 3-D analyses differ significantly from a slope map or results from one-dimensional (1-D) analyses.

  5. Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century

    Science.gov (United States)

    Pagán, Brianna R.; Ashfaq, Moetasim; Rastogi, Deeksha; Kendall, Donald R.; Kao, Shih-Chieh; Naz, Bibi S.; Mei, Rui; Pal, Jeremy S.

    2016-09-01

    The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of California, which is the most populous and agriculturally productive in the United States, depends on an extensive artificial water storage and conveyance system primarily for irrigated agriculture, municipal and industrial supply and hydropower generation. Here we take an integrative high-resolution ensemble modeling approach to examine near term climate change impacts on all imported and local sources of water supply to Southern California. While annual precipitation is projected to remain the same or slightly increase, rising temperatures result in a shift towards more rainfall, reduced cold season snowpack and earlier snowmelt. Associated with these hydrological changes are substantial increases in the frequency and the intensity of both drier conditions and flooding events. The 50 year extreme daily maximum precipitation and runoff events are 1.5-6 times more likely to occur depending on the water supply basin. Simultaneously, a clear deficit in total annual runoff over mountainous snow generating regions like the Sierra Nevada is projected. On one hand, the greater probability of drought decreases imported water supply availability. On the other hand, earlier snowmelt and significantly stronger winter precipitation events pose increased flood risk requiring water releases from control reservoirs, which may potentially decrease water availability outside of the wet season. Lack of timely local water resource expansion coupled with projected climate changes and population increases may leave the area in extended periods of shortages.

  6. Geology of conglomerate in Vempalle formation: new insights in stratigraphy of Papaghni Group, southwestern margin of Cuddapah Basin, India

    International Nuclear Information System (INIS)

    The southwestern part of Cuddapah Basin consists of two distinct types of rocks, i.e. lower arenaceous and upper calcareous, which are termed as Gulcheru quartzite and Vempalle formation. Results of field and subsurface exploration revealed two repeated sedimentary sequences of arenaceous-argillaceous-carbonate units in Papaghni Group. These sequences represent marine transgression and regression cycles in Papaghni Group. Field characteristics of conglomerate (Vempalle Conglomerate), observed above massive dolostone in lower part of Vempalle Formation, show extra-formational and polymictic nature. Subsurface exploration in Tumallapalle and extension areas has also proved continuity of Vempalle conglomerate over 25 km along strike and 3.10 km along downdip direction. Secondly, the gradational contact was observed between Gulcheru shale and massive dolostone in surface exposures, which was also confirmed in one borehole (BH No. TPL-II/83) drilled more than a kilometer vertical depth. The strike and dip continuity (of Vempalle conglomerate) and gradational contact (in Gulcheru) have given a new understanding to the stratigraphic position of rock sequence in Papaghni Group. In the present study, it is proposed to revise the stratigraphic succession by placing carbonate unit of massive dolostone as a part of Gulcheru Formation, and Vempalle Formation would commence with the Vempalle conglomerate. (author)

  7. Functional Analysis of In-frame Indel ARID1A Mutations Reveals New Regulatory Mechanisms of Its Tumor Suppressor Functions

    Directory of Open Access Journals (Sweden)

    Bin Guan

    2012-10-01

    Full Text Available AT-rich interactive domain 1A (ARID1A has emerged as a new tumor suppressor in which frequent somatic mutations have been identified in several types of human cancers. Although most ARID1A somatic mutations are frame-shift or nonsense mutations that contribute to mRNA decay and loss of protein expression, 5% of ARID1A mutations are in-frame insertions or deletions (indels that involve only a small stretch of peptides. Naturally occurring in-frame indel mutations provide unique and useful models to explore the biology and regulatory role of ARID1A. In this study, we analyzed indel mutations identified in gynecological cancers to determine how these mutations affect the tumor suppressor function of ARID1A. Our results demonstrate that all in-frame mutants analyzed lost their ability to inhibit cellular proliferation or activate transcription of CDKN1A, which encodes p21, a downstream effector of ARID1A. We also showed that ARID1A is a nucleocytoplasmic protein whose stability depends on its subcellular localization. Nuclear ARID1A is less stable than cytoplasmic ARID1A because ARID1A is rapidly degraded by the ubiquitin-proteasome system in the nucleus. In-frame deletions affecting the consensus nuclear export signal reduce steady-state protein levels of ARID1A. This defect in nuclear exportation leads to nuclear retention and subsequent degradation. Our findings delineate a mechanism underlying the regulation of ARID1A subcellular distribution and protein stability and suggest that targeting the nuclear ubiquitin-proteasome system can increase the amount of the ARID1A protein in the nucleus and restore its tumor suppressor functions.

  8. Energy map of southwestern Wyoming, Part B: oil and gas, oil shale, uranium, and solar

    Science.gov (United States)

    Biewick, Laura R.H.; Wilson, Anna B.

    2014-01-01

    The U.S. Geological Survey (USGS) has compiled Part B of the Energy Map of Southwestern Wyoming for the Wyoming Landscape Conservation Initiative (WLCI). Part B consists of oil and gas, oil shale, uranium, and solar energy resource information in support of the WLCI. The WLCI represents the USGS partnership with other Department of the Interior Bureaus, State and local agencies, industry, academia, and private landowners, all of whom collaborate to maintain healthy landscapes, sustain wildlife, and preserve recreational and grazing uses while developing energy resources in southwestern Wyoming. This product is the second and final part of the Energy Map of Southwestern Wyoming series (also see USGS Data Series 683, http://pubs.usgs.gov/ds/683/), and encompasses all of Carbon, Lincoln, Sublette, Sweetwater, and Uinta Counties, as well as areas in Fremont County that are in the Great Divide and Green River Basins.

  9. Naturally occurring arsenic in the Miocene Hawthorn Group, southwestern Florida: Potential implication for phosphate mining

    International Nuclear Information System (INIS)

    To understand the mineralogical association, concentration, and distribution of arsenic (As) in the Hawthorn Group, the chemical and mineralogical composition of 362 samples that were collected from 16 cores in southwestern Florida were examined in detail. In the study area, the Hawthorn Group consisted primarily of a basal carbonate unit (the Arcadia Formation) and an upper siliciclastic unit (The Peace River Formation). The Peace River Formation contains appreciable amounts of phosphate and is currently being exploited for phosphate ore. Samples were taken from cores of each formation at intervals of 7.5 m. In addition, to the interval samples, sections likely to have high As concentrations, such as zones with pyrite crystals, hydrous ferric oxides, green clays, and organic material, were collected and analyzed. Bulk As concentrations were determined by hydride generation-atomic fluorescence spectrometry (HG-AFS) after digestion with aqua regia (3:1 HCl and HNO3). The elements Fe, Al, Si, Mg, Ca, S, and P were measured on the same solutions by inductively coupled plasma optical emission spectrometry (ICP-OES). The identification of discrete minerals was aided by scanning electron microscopy (SEM) and chemical compositions within the sample matrix and in individual minerals were obtained by electron-probe microanalysis (EMPA). This detailed mineralogical and geochemical study demonstrated that: (1) As in the Hawthorn Group varied from formation to formation and was mostly concentrated in trace minerals, such as pyrite; (2) average As concentrations significantly changed from 8.8 mg/kg (σ = 8.6 mg/kg) in the Peace River Formation to 3.0 mg/kg (σ = 3.7 mg/kg) in the Tampa Member of the Arcadia Formation. Arsenic concentrations for all Hawthorn samples varied from 0.1 to 69.0 mg/kg; (3) pyrite, with one exception, occurred as framboids and was unevenly distributed throughout the Hawthorn Group; (4) pyrite framboids were located inside a francolite (carbonate

  10. Subsurface and petroleum geology of the southwestern Santa Clara Valley ("Silicon Valley"), California

    Science.gov (United States)

    Stanley, Richard G.; Jachens, Robert C.; Lillis, Paul G.; McLaughlin, Robert J.; Kvenvolden, Keith A.; Hostettler, Frances D.; McDougall, Kristin A.; Magoon, Leslie B.

    2002-01-01

    Gravity anomalies, historical records of exploratory oil wells and oil seeps, new organic-geochemical results, and new stratigraphic and structural data indicate the presence of a concealed, oil-bearing sedimentary basin beneath a highly urbanized part of the Santa Clara Valley, Calif. A conspicuous isostatic-gravity low that extends about 35 km from Palo Alto southeastward to near Los Gatos reflects an asymmetric, northwest-trending sedimentary basin comprising low-density strata, principally of Miocene age, that rest on higher-density rocks of Mesozoic and Paleogene(?) age. Both gravity and well data show that the low-density rocks thin gradually to the northeast over a distance of about 10 km. The thickest (approx 4 km thick) accumulation of low-density material occurs along the basin's steep southwestern margin, which may be controlled by buried, northeast-dipping normal faults that were active during the Miocene. Movement along these hypothetical normal faults may been contemporaneous (approx 17–14 Ma) with sedimentation and local dacitic and basaltic volcanism, possibly in response to crustal extension related to passage of the northwestward-migrating Mendocino triple junction. During the Pliocene and Quaternary, the normal faults and Miocene strata were overridden by Mesozoic rocks, including the Franciscan Complex, along northeastward-vergent reverse and thrust faults of the Berrocal, Shannon, and Monte Vista Fault zones. Movement along these fault zones was accompanied by folding and tilting of strata as young as Quaternary and by uplift of the modern Santa Cruz Mountains; the fault zones remain seismically active. We attribute the Pliocene and Quaternary reverse and thrust faulting, folding, and uplift to compression caused by local San Andreas Fault tectonics and regional transpression along the Pacific-North American Plate boundary. Near the southwestern margin of the Santa Clara Valley, as many as 20 exploratory oil wells were drilled between 1891

  11. Agricultural sustainability in the semi-arid Near East

    Directory of Open Access Journals (Sweden)

    F. Hole

    2007-05-01

    Full Text Available Agriculture began in the eastern Mediterranean Levantine Corridor about 11000 years ago toward the end of the Younger Dryas when aridity had diminished wild food resources. During the subsequent Climatic Optimum, agricultural villages spread rapidly but subsequent climatic changes on centennial to millennial scales resulted in striking oscillations in settlement, especially in marginal areas. Natural climate change thus alternately enhanced and diminished the agricultural potential of the land. Growing populations and more intensive land us, both for agriculture and livestock, have led to changes in the structure of vegetation, hydrology, and land quality. Over the millennia, political and economic interventions, warfare and incursions by nomadic herding tribes all impacted sustainability of agriculture and the ability of the land to supports its populations. In much of the region today, agricultural land use is not sustainable given existing technology and national priorities. The Near Eastern case is instructive because of the quality of information, the length of the record, and the pace of modern change.

  12. Verification of watershed vegetation restoration policies, arid China

    Science.gov (United States)

    Zhang, Chengqi; Li, Yu

    2016-07-01

    Verification of restoration policies that have been implemented is of significance to simultaneously reduce global environmental risks while also meeting economic development goals. This paper proposed a novel method according to the idea of multiple time scales to verify ecological restoration policies in the Shiyang River drainage basin, arid China. We integrated modern pollen transport characteristics of the entire basin and pollen records from 8 Holocene sedimentary sections, and quantitatively reconstructed the millennial-scale changes of watershed vegetation zones by defining a new pollen-precipitation index. Meanwhile, Empirical Orthogonal Function method was used to quantitatively analyze spatial and temporal variations of Normalized Difference Vegetation Index in summer (June to August) of 2000-2014. By contrasting the vegetation changes that mainly controlled by millennial-scale natural ecological evolution with that under conditions of modern ecological restoration measures, we found that vegetation changes of the entire Shiyang River drainage basin are synchronous in both two time scales, and the current ecological restoration policies met the requirements of long-term restoration objectives and showed promising early results on ecological environmental restoration. Our findings present an innovative method to verify river ecological restoration policies, and also provide the scientific basis to propose future emphasizes of ecological restoration strategies.

  13. Torpor and basking in a small arid zone marsupial

    Science.gov (United States)

    Warnecke, Lisa; Turner, James M.; Geiser, Fritz

    2008-01-01

    The high energetic cost associated with endothermic rewarming from torpor is widely seen as a major disadvantage of torpor. We tested the hypothesis that small arid zone marsupials, which have limited access to energy in the form of food but ample access to solar radiation, employ basking to facilitate arousal from torpor and reduce the costs of rewarming. We investigated torpor patterns and basking behaviour in free-ranging fat-tailed dunnarts Sminthopsis crassicaudata (10 g) in autumn and winter using small, internal temperature-sensitive transmitters. Torpid animals emerged from their resting sites in cracking soil at ˜1000 h with body temperatures as low as 14.6°C and positioned themselves in the sun throughout the rewarming process. On average, torpor duration in autumn was shorter, and basking was less pronounced in autumn than in winter. These are the first observations of basking during rewarming in S. crassicaudata and only the second direct evidence of basking in a torpid mammal for the reduction of energetic costs during arousal from torpor and normothermia. Our findings suggest that although overlooked in the past, basking may be widely distributed amongst heterothermic mammals. Therefore, the energetic benefits from torpor use in wild animals may currently be underestimated.

  14. Water harvesting techniques for small communities in arid areas.

    Science.gov (United States)

    Yuen, E; Anda, M; Mathew, K; Ho, G

    2001-01-01

    Limited water resources exist in numerous remote indigenous settlements around Australia. Indigenous people in these communities are still living in rudimentary conditions while their urban counterparts have full amenities, large scale water supplies and behavioral practices which may not be appropriate for an arid continent but are supported by extensive infrastructure in higher rainfall coastal areas. As remote indigenous communities continue to develop, their water use will increase, and in some cases, costly solutions may have to be implemented to augment supplies. Water harvesting techniques have been applied in settlements on a small scale for domestic and municipal purposes, and in the large, broadacre farm setting for productive use of the water. The techniques discussed include swales, infiltration basins, infiltration trenches and "sand dam" basins. This paper reviews the applications of water harvesting relevant to small communities for land rehabilitation, landscaping and flood control. Landscaping is important in these communities as it provides shelter from the sun and wind, reduces soil erosion and hence reduced airborne dust, and in some cases provides food and nutrition. Case studies of water harvesting systems applied in the Pilbara Region, Western Australia for landscaping around single dwellings in Jigalong and Cheeditha, in a permaculture garden in Wittenoon and at a college and carpark in Karratha are described.

  15. Comparison modeling for alpine vegetation distribution in an arid area.

    Science.gov (United States)

    Zhou, Jihua; Lai, Liming; Guan, Tianyu; Cai, Wetao; Gao, Nannan; Zhang, Xiaolong; Yang, Dawen; Cong, Zhentao; Zheng, Yuanrun

    2016-07-01

    Mapping and modeling vegetation distribution are fundamental topics in vegetation ecology. With the rise of powerful new statistical techniques and GIS tools, the development of predictive vegetation distribution models has increased rapidly. However, modeling alpine vegetation with high accuracy in arid areas is still a challenge because of the complexity and heterogeneity of the environment. Here, we used a set of 70 variables from ASTER GDEM, WorldClim, and Landsat-8 OLI (land surface albedo and spectral vegetation indices) data with decision tree (DT), maximum likelihood classification (MLC), and random forest (RF) models to discriminate the eight vegetation groups and 19 vegetation formations in the upper reaches of the Heihe River Basin in the Qilian Mountains, northwest China. The combination of variables clearly discriminated vegetation groups but failed to discriminate vegetation formations. Different variable combinations performed differently in each type of model, but the most consistently important parameter in alpine vegetation modeling was elevation. The best RF model was more accurate for vegetation modeling compared with the DT and MLC models for this alpine region, with an overall accuracy of 75 % and a kappa coefficient of 0.64 verified against field point data and an overall accuracy of 65 % and a kappa of 0.52 verified against vegetation map data. The accuracy of regional vegetation modeling differed depending on the variable combinations and models, resulting in different classifications for specific vegetation groups.

  16. Heterogeneous aquifer system modelisation under semi-arid climate

    Science.gov (United States)

    Drias, Tarek; Toubal, Ahmed Cherif

    2010-05-01

    The studied zone is a part of the Mellegne's (North-East of Algeria) under pound, this zone is characterised by its semi-arid climate. The water bearing system is formed by the plio-quaternairy alluviums resting on a marley substratuim of age Eocene. The geostatiscitcs approach of the hydrodynamics parameters (Hydrolic load, transmisivity) allowed the study of their spatial distrubution (casting) by the method of Krigeage by blocks and the identification of zones with water-bearing potentialities. In this respect, the zone of Ain Chabro which, is situated in the South of the plain shows the best values of the transmisivity...... The use of a bidimensinnel model in the differences ended in the permanent regime allowed us to establish the global balence sheet (overall assessment) of the tablecloth and to refine the transmisivity field. These would vary more exactley between 10-4 to 10-2 m²/s. The method associating the probability appraoch of Krigeage to that determining the model has facilited the wedging of the model and clarified the inflitration value. Keys words: hydrodynamics, geostatiscitcs, Modeling, Chabro, Tébessa.

  17. Verification of watershed vegetation restoration policies, arid China

    Science.gov (United States)

    Zhang, Chengqi; Li, Yu

    2016-07-01

    Verification of restoration policies that have been implemented is of significance to simultaneously reduce global environmental risks while also meeting economic development goals. This paper proposed a novel method according to the idea of multiple time scales to verify ecological restoration policies in the Shiyang River drainage basin, arid China. We integrated modern pollen transport characteristics of the entire basin and pollen records from 8 Holocene sedimentary sections, and quantitatively reconstructed the millennial-scale changes of watershed vegetation zones by defining a new pollen-precipitation index. Meanwhile, Empirical Orthogonal Function method was used to quantitatively analyze spatial and temporal variations of Normalized Difference Vegetation Index in summer (June to August) of 2000–2014. By contrasting the vegetation changes that mainly controlled by millennial-scale natural ecological evolution with that under conditions of modern ecological restoration measures, we found that vegetation changes of the entire Shiyang River drainage basin are synchronous in both two time scales, and the current ecological restoration policies met the requirements of long-term restoration objectives and showed promising early results on ecological environmental restoration. Our findings present an innovative method to verify river ecological restoration policies, and also provide the scientific basis to propose future emphasizes of ecological restoration strategies.

  18. Agricultural sustainability in the semi-arid Near East

    Directory of Open Access Journals (Sweden)

    F. Hole

    2006-07-01

    Full Text Available Agriculture began in the eastern Mediterranean Levantine Corridor about 11 000 years ago toward the end of the Younger Dryas when aridity had diminished wild food resources. During the subsequent Climatic Optimum, agricultural villages spread rapidly but subsequent climatic changes on centennial to millennial scales resulted in striking oscillations in settlement, especially in marginal areas. Natural climate change thus alternately enhanced and diminished the agricultural potential of the land. Growing populations and more intensive land use, both for agriculture and livestock, have led to changes in the structure of vegetation, hydrology, and land quality. Over the millennia, political and economic interventions, warfare and incursions by nomadic herding tribes all impacted sustainability of agriculture and the ability of the land to support its populations. In much of the region today, agricultural land use is not sustainable given existing technology and national priorities. The Near Eastern case is instructive because of the quality of information, the length of the record, and the pace of modern change.

  19. Comparison modeling for alpine vegetation distribution in an arid area.

    Science.gov (United States)

    Zhou, Jihua; Lai, Liming; Guan, Tianyu; Cai, Wetao; Gao, Nannan; Zhang, Xiaolong; Yang, Dawen; Cong, Zhentao; Zheng, Yuanrun

    2016-07-01

    Mapping and modeling vegetation distribution are fundamental topics in vegetation ecology. With the rise of powerful new statistical techniques and GIS tools, the development of predictive vegetation distribution models has increased rapidly. However, modeling alpine vegetation with high accuracy in arid areas is still a challenge because of the complexity and heterogeneity of the environment. Here, we used a set of 70 variables from ASTER GDEM, WorldClim, and Landsat-8 OLI (land surface albedo and spectral vegetation indices) data with decision tree (DT), maximum likelihood classification (MLC), and random forest (RF) models to discriminate the eight vegetation groups and 19 vegetation formations in the upper reaches of the Heihe River Basin in the Qilian Mountains, northwest China. The combination of variables clearly discriminated vegetation groups but failed to discriminate vegetation formations. Different variable combinations performed differently in each type of model, but the most consistently important parameter in alpine vegetation modeling was elevation. The best RF model was more accurate for vegetation modeling compared with the DT and MLC models for this alpine region, with an overall accuracy of 75 % and a kappa coefficient of 0.64 verified against field point data and an overall accuracy of 65 % and a kappa of 0.52 verified against vegetation map data. The accuracy of regional vegetation modeling differed depending on the variable combinations and models, resulting in different classifications for specific vegetation groups. PMID:27307276

  20. Verification of watershed vegetation restoration policies, arid China

    Science.gov (United States)

    Zhang, Chengqi; Li, Yu

    2016-01-01

    Verification of restoration policies that have been implemented is of significance to simultaneously reduce global environmental risks while also meeting economic development goals. This paper proposed a novel method according to the idea of multiple time scales to verify ecological restoration policies in the Shiyang River drainage basin, arid China. We integrated modern pollen transport characteristics of the entire basin and pollen records from 8 Holocene sedimentary sections, and quantitatively reconstructed the millennial-scale changes of watershed vegetation zones by defining a new pollen-precipitation index. Meanwhile, Empirical Orthogonal Function method was used to quantitatively analyze spatial and temporal variations of Normalized Difference Vegetation Index in summer (June to August) of 2000–2014. By contrasting the vegetation changes that mainly controlled by millennial-scale natural ecological evolution with that under conditions of modern ecological restoration measures, we found that vegetation changes of the entire Shiyang River drainage basin are synchronous in both two time scales, and the current ecological restoration policies met the requirements of long-term restoration objectives and showed promising early results on ecological environmental restoration. Our findings present an innovative method to verify river ecological restoration policies, and also provide the scientific basis to propose future emphasizes of ecological restoration strategies. PMID:27470948

  1. SHOCK-CLOUD INTERACTION AND PARTICLE ACCELERATION IN THE SOUTHWESTERN LIMB OF SN 1006

    Energy Technology Data Exchange (ETDEWEB)

    Miceli, M.; Orlando, S.; Bocchino, F. [INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134 Palermo (Italy); Acero, F. [ORAU/NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Dubner, G. [Instituto de Astronomía y Física del Espacio (IAFE), UBA-CONICET, CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Decourchelle, A., E-mail: miceli@astropa.unipa.it [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Université Paris Diderot, CE-Saclay, F-91191 Gif-sur-Yvette (France)

    2014-02-20

    The supernova remnant SN 1006 is a powerful source of high-energy particles and evolves in a relatively tenuous and uniform environment despite interacting with an atomic cloud in its northwestern limb. The X-ray image of SN 1006 reveals an indentation in the southwestern part of the shock front and the H I maps show an isolated (southwestern) cloud, having the same velocity as the northwestern cloud, whose morphology fits perfectly in the indentation. We performed spatially resolved spectral analysis of a set of small regions in the southwestern nonthermal limb and studied the deep X-ray spectra obtained within the XMM-Newton SN 1006 Large Program. We also analyzed archive H I data, obtained by combining single-dish and interferometric observations. We found that the best-fit value of N {sub H} derived from the X-ray spectra significantly increases in regions corresponding to the southwestern cloud, while the cutoff energy of the synchrotron emission decreases. The N {sub H} variation corresponds perfectly with the H I column density of the southwestern cloud, as measured from the radio data. The decrease in the cutoff energy at the indentation clearly reveals that the back side of the cloud is actually interacting with the remnant. The southwestern limb therefore presents a unique combination of efficient particle acceleration and high ambient density, thus being the most promising region for γ-ray hadronic emission in SN 1006. We estimate that such emission will be detectable with the Fermi telescope within a few years.

  2. Land use and habitat conditions across the southwestern Wyoming sagebrush steppe: development impacts, management effectiveness and the distribution of invasive plants

    Science.gov (United States)

    Manier, Daniel J.; Aldridge, Cameron L.; Anderson, Patrick; Chong, Geneva; Homer, Collin G.; O'Donnell, Michael S.; Schell, Spencer

    2011-01-01

    For the past several years, USGS has taken a multi-faceted approach to investigating the condition and trends in sagebrush steppe ecosystems. This recent effort builds upon decades of work in semi-arid ecosystems providing a specific, applied focus on the cumulative impacts of expanding human activities across these landscapes. Here, we discuss several on-going projects contributing to these efforts: (1) mapping and monitoring the distribution and condition of shrub steppe communities with local detail at a regional scale, (2) assessing the relationships between specific, land-use features (for example, roads, transmission lines, industrial pads) and invasive plants, including their potential (environmentally defined) distribution across the region, and (3) monitoring the effects of habitat treatments on the ecosystem, including wildlife use and invasive plant abundance. This research is focused on the northern sagebrush steppe, primarily in Wyoming, but also extending into Montana, Colorado, Utah and Idaho. The study area includes a range of sagebrush types (including, Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. wyomingensis, Artemisia tridentata ssp. vaseyana, Artemisia nova) and other semi-arid shrubland types (for example, Sarcobatus vermiculatus, Atriplex confertifolia, Atriplex gardneri), impacted by extensive interface between steppe ecosystems and industrial energy activities resulting in a revealing multiple-variable analysis. We use a combination of remote sensing (AWiFS (1 Any reference to platforms, data sources, equipment, software, patented or trade-marked methods is for information purposes only. It does not represent endorsement of the U.S.D.I., U.S.G.S. or the authors), Landsat and Quickbird platforms), Geographic Information System (GIS) design and data management, and field-based, replicated sampling to generate multiple scales of data representing the distribution of shrub communities for the habitat inventory. Invasive plant

  3. Decreased expression of the ARID1A gene is associated with poor prognosis in primary gastric cancer.

    Directory of Open Access Journals (Sweden)

    Dan-dan Wang

    Full Text Available BACKGROUND: The ARID1A gene encodes adenine-thymine (AT-rich interactive domain-containing protein 1A, which participates in chromatin remodeling. ARID1A has been showed to function as a tumor suppressor in various cancer types. In the current study, we investigated the expression and prognosis value of ARID1A in primary gastric cancer. Meanwhile, the biological role of ARID1A was further investigated using cell model in vitro. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the role of ARID1A gene in primary gastric cancer pathogenesis, real-time quantitative PCR and western blotting were used to examine the ARID1A expression in paired cancerous and noncancerous tissues. Results revealed decreased ARID1A mRNA (P = 0.0029 and protein (P = 0.0015 expression in most tumor-bearing tissues compared with the matched adjacent non-tumor tissues, and in gastric cancer cell lines. To further investigate the clinicopathological and prognostic roles of ARID1A expression, we performed immunohistochemical analyses of the 224 paraffin-embedded gastric cancer tissue blocks. Data revealed that the loss of ARID1A expression was significantly correlated with T stage (P = 0.001 and grade (P = 0.006. Consistent with these results, we found that loss of ARID1A expression was significantly correlated with poor survival in gastric cancer patients (P = 0.003. Cox regression analyses showed that ARID1A expression was an independent predictor of overall survival (P = 0.029. Furthermore, the functions of ARID1A in the proliferation and colony formation of gastric cell lines were analyzed by transfecting cells with full-length ARID1A expression vector or siRNA targeting ARID1A. Restoring ARID1A expression in gastric cancer cells significantly inhibited cell proliferation and colony formation. Silencing ARID1A expression in gastric epithelial cell line significantly enhanced cell growth rate. CONCLUSIONS/SIGNIFICANCE: Our data suggest that ARID1A may play an important role

  4. Discriminating sediment archives and sedimentary processes in the arid endorheic Ejina Basin, NW China using a robust geochemical approach

    Science.gov (United States)

    Yu, Kaifeng; Hartmann, Kai; Nottebaum, Veit; Stauch, Georg; Lu, Huayu; Zeeden, Christian; Yi, Shuangwen; Wünnemann, Bernd; Lehmkuhl, Frank

    2016-04-01

    Geochemical characteristics have been intensively used to assign sediment properties to paleoclimate and provenance. Nonetheless, in particular concerning the arid context, bulk geochemistry of different sediment archives and corresponding process interpretations are hitherto elusive. The Ejina Basin, with its suite of different sediment archives, is known as one of the main sources for the loess accumulation on the Chinese Loess Plateau. In order to understand mechanisms along this supra-regional sediment cascade, it is crucial to decipher the archive characteristics and formation processes. To address these issues, five profiles in different geomorphological contexts were selected. Analyses of X-ray fluorescence and diffraction, grain size, optically stimulated luminescence and radiocarbon dating were performed. Robust factor analysis was applied to reduce the attribute space to the process space of sedimentation history. Five sediment archives from three lithologic units exhibit geochemical characteristics as follows: (i) aeolian sands have high contents of Zr and Hf, whereas only Hf can be regarded as a valuable indicator to discriminate the coarse sand proportion; (ii) sandy loess has high Ca and Sr contents which both exhibit broad correlations with the medium to coarse silt proportions; (iii) lacustrine clays have high contents of felsic, ferromagnesian and mica source elements e.g., K, Fe, Ti, V, and Ni; (iv) fluvial sands have high contents of Mg, Cl and Na which may be enriched in evaporite minerals; (v) alluvial gravels have high contents of Cr which may originate from nearby Cr-rich bedrock. Temporal variations can be illustrated by four robust factors: weathering intensity, silicate-bearing mineral abundance, saline/alkaline magnitude and quasi-constant aeolian input. In summary, the bulk-composition of the late Quaternary sediments in this arid context is governed by the nature of the source terrain, weak chemical weathering, authigenic minerals

  5. Large-scale hydrological modelling in the semi-arid north-east of Brazil

    Science.gov (United States)

    Güntner, Andreas

    2002-07-01

    Semi-arid areas are, due to their climatic setting, characterized by small water resources. An increasing water demand as a consequence of population growth and economic development as well as a decreasing water availability in the course of possible climate change may aggravate water scarcity in future, which often exists already for present-day conditions in these areas. Understanding the mechanisms and feedbacks of complex natural and human systems, together with the quantitative assessment of future changes in volume, timing and quality of water resources are a prerequisite for the development of sustainable measures of water management to enhance the adaptive capacity of these regions. For this task, dynamic integrated models, containing a hydrological model as one component, are indispensable tools. The main objective of this study is to develop a hydrological model for the quantification of water availability in view of environmental change over a large geographic domain of semi-arid environments. The study area is the Federal State of Ceará (150 000 km2) in the semi-arid north-east of Brazil. Mean annual precipitation in this area is 850 mm, falling in a rainy season with duration of about five months. Being mainly characterized by crystalline bedrock and shallow soils, surface water provides the largest part of the water supply. The area has recurrently been affected by droughts which caused serious economic losses and social impacts like migration from the rural regions. The hydrological model Wasa (Model of Water Availability in Semi-Arid Environments) developed in this study is a deterministic, spatially distributed model being composed of conceptual, process-based approaches. Water availability (river discharge, storage volumes in reservoirs, soil moisture) is determined with daily resolution. Sub-basins, grid cells or administrative units (municipalities) can be chosen as spatial target units. The administrative units enable the coupling of Wasa in

  6. Acoustic Velocity Of The Sediments Offshore Southwestern Taiwan

    Science.gov (United States)

    Tsai, C.; Liu, C.; Huang, P.

    2004-12-01

    Along the Manila Trench south of 21øXN, deep-sea sediments are being underthrusted beneath the Taiwan accretionary prism which is composed of the Kaoping Slope and Hengchun Ridge. Offshore southwestern Taiwan, foreland sediments and Late Miocene strata of the Tainan Basin are being accreted onto the fold-and thrust belt of the syn-collision accretionary wedge of the Kaoping Slope. The Kaoping Slope consists of thick Neogene to Recent siliciclastics deformed by fold-and-thrust structures and mud diapers. These Pliocene-Quaternary sediments deposited in the Kaoping Shelf and upper slope area are considered to be paleo-channel deposits confined by NNE-SSW trend mud diapiric structure. Seismic P-wave velocities of the sediment deposited in the Kaoping Shelf and Kaoping Slope area are derived from mutichannel seismic reflection data and wide-angle reflection and refraction profiles collected by sonobuoys. Sediment velocity structures constrained from mutichannel seismic reflection data using velocity spectrum analysis method and that derived from sonobuoy data using tau-sum inversion method are compared, and they both provide consistent velocity structures. Seismic velocities were analyzed along the seismic profile from the surface to maximum depths of about 2.0 km below the seafloor. Our model features a sediment layer1 with 400 ms in thickness and a sediment layer2 with 600 ms in thickness. For the shelf sediments, we observe a linear interval velocity trend of V=1.53+1.91T in layer1, and V=1.86+0.87T in layer2, where T is the one way travel time within the layer. For the slop sediment, the trend of V=1.47+1.93T in layer1, and V=1.70+1.55T in layer2. The layer1¡¦s velocities gradients are similar between the shelf (1.91 km/sec2) and the slope(1.93 km/sec2). It means layer1 distributes over the slope and shelf widely. The result of the sediment velocity gradients in this area are in good agreement with that reported for the south Atlantic continental margins.

  7. Multiple episodes of hydrothermal activity and epithermal mineralization in the southwestern Nevada volcanic field and their relations to magmatic activity, volcanism and regional extension

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.I.; Noble, D.C.; Jackson, M.C. [Univ. of Nevada, Reno, NV (United States)] [and others

    1994-12-31

    Volcanic rocks of middle Miocene age and underlying pre-Mesozoic sedimentary rocks host widely distributed zones of hydrothermal alteration and epithermal precious metal, fluorite and mercury deposits within and peripheral to major volcanic and intrusive centers of the southwestern Nevada volcanic field (SWNVF) in southern Nevada, near the southwestern margin of the Great Basin of the western United States. Radiometric ages indicate that episodes of hydrothermal activity mainly coincided with and closely followed major magmatic pulses during the development of the field and together spanned more than 4.5 m.y. Rocks of the SWNVF consist largely of rhyolitic ash-flow sheets and intercalated silicic lava domes, flows and near-vent pyroclastic deposits erupted between 15.2 and 10 Ma from vent areas in the vicinity of the Timber Mountain calderas, and between about 9.5 and 7 Ma from the outlying Black Mountain and Stonewall Mountain centers. Three magmatic stages can be recognized: the main magmatic stage, Mountain magmatic stage (11.7 to 10.0 Ma), and the late magmatic stage (9.4 to 7.5 Ma).

  8. Does woodland encroachment impact water?: An ecohydrology study of western juniper (Juniperus occidentalis) and other semi-arid conifers in the western U.S.

    Science.gov (United States)

    Niemeyer, R. J.; Link, T. E.; Heinse, R.; Seyfried, M. S.; Flerchinger, G. N.; Klos, P. Z.

    2015-12-01

    Semi-arid conifer species including western juniper (Juniperus occidentalis) among other pinyon and juniper (P-J) species have expanded into grass and shrub-dominated landscapes in the western U.S. Despite the importance of land cover changes to hydrological fluxes in these water-limited systems, there have been few process-based ecohydrology studies of western juniper encroachment. Furthermore, many conclusions about the impact of P-J encroachment on streamflow are limited to several studies in the southwestern U.S. Our objectives are to: a) assess how western juniper will impact above-ground hydrological processes, b) assess how western juniper will alter below-ground hydrological processes, c) assess how changes in P-J cover alters deep drainage across diverse climates of the western U.S. To accomplish these objectives we used a combination of continuous lysimeter and soil moisture measurements, periodic snow surveys, electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys, simulations with the Simultaneous Heat and Water (SHAW) model and broad, spatially-coarse simulations with the atmosphere-vegetation-soil component of the HBV model. Juniper trees by both intercepting snow and increasing below-canopy snow melt caused tree wells to form throughout the winter. These tree wells increased snow redistribution to the base of the trees. Soil moisture in the interspace dominated by sagebrush, forbes, and grasses drops early in the season, but late season soil moisture changes are moderated by juniper. There is evidence that junipers continue to transpire soil moisture both late into the summer and at up to 3 meters deep. HBV simulations revealed that the potential for increases in deep drainage with a change from P-J to grass cover is principally controlled by the timing instead of the total precipitation. Simulations confirm previous empirical studies that landscapes in monsoon-dominated climates of the southwestern U.S. show negligible

  9. Effects of seasonal ambient heat stress (spring vs. summer) on physiological and metabolic variables in hair sheep located in an arid region

    Science.gov (United States)

    Macías-Cruz, U.; López-Baca, M. A.; Vicente, R.; Mejía, A.; Álvarez, F. D.; Correa-Calderón, A.; Meza-Herrera, C. A.; Mellado, M.; Guerra-Liera, J. E.; Avendaño-Reyes, L.

    2016-08-01

    Twenty Dorper × Pelibuey primiparous ewes were used to evaluate effects of seasonal ambient heat stress (i.e., spring vs. summer) on physiological and metabolic responses under production conditions in an arid region. Ten ewes experiencing summer heat stress (i.e., temperature = 34.8 ± 4.6 °C; THI = 81.6 ± 3.2 units) and 10 under spring thermoneutral conditions (temperature = 24.2 ± 5.4 °C; THI = 68.0 ± 4.8 units) were corralled together to measure rectal temperature, respiratory frequency, and skin temperatures at 0600, 1200, 1800, and 2400 h on four occasions over 40 days. Blood metabolite and electrolyte concentrations were also measured at 0600 and 1800 hours. Data were analyzed with a completely randomized design using repeated measurements in time. Rectal and skin temperatures, as well as respiratory frequency, were higher ( P hair breed ewes in an arid region, which included blood metabolite and electrolyte adjustments to efficiently cope with summer heat stress.

  10. Two-Source Energy Balance Model Evaluation for Mapping Evapotranspiration on the Semi- arid Southern High Plains

    Science.gov (United States)

    Gowda, P. H.; Chavez, J. L.; Colaizzi, P. D.; Evett, S. R.; Howell, T. A.; Copeland, K.

    2007-05-01

    Evapotranspiration (ET) is an essential component of the water balance and a major consumptive use of irrigation water and precipitation on cropland. In this study, we applied the Two-Source Energy Balance (T-SEB) model to estimate hourly ET from Landsat Thematic Mapper (TM) data for the semi-arid Southern High Plains of the United States where more than 90 percent of the groundwater withdrawals are used for irrigation. For this purpose, a Landsat TM image covering a major portion of the Southern High Plains (parts of Texas Panhandle and northeastern New Mexico) was acquired for 23 July 2006 for the overpass at 11:26 AM CST. Atmospheric correction on the TM imagery was done using MODTRAN, an atmospheric radiative transfer model. Comprehensive ground-truth data were collected to develop a detailed land use map showing major crops grown in the region. Performance of the T SEB model was evaluated by comparing mapped ET data with measured hourly ET data on five weighing lysimeters at Bushland, TX [35 Deg. 11' N, 102 Deg. 06' W; 1,170 m elevation MSL] managed by the Conservation and Production Research Laboratory, USDA-ARS. Lysimeter-measured ET rates varied from 0.24 to 0.71 mm/h. Comparison of estimated hourly mapped ET values with lysimetric measurements had an accuracy within 6% of the measured ET (r2=0.99), with a root mean squared error of 0.03 mm/h. These results support the use of the T-SEB model for the semi-arid Southern High Plains; however, more evaluation is needed for different agroclimatological conditions in the region.

  11. Simulation of water use and herbage growth in arid regions : a re-evaluation and further development of the model ‘arid crop’

    NARCIS (Netherlands)

    Keulen, van H.; Seligman, N.G.; Benjamin, R.W.

    1981-01-01

    A previously published simulation model, describing growth of annual pasture under semi-arid conditions, is re-examined and further developed on the basis of additional experimental information. Major changes introduced are connected with the partitioning of above-ground dry matter into leaves and n

  12. Date palm (Phoenix dactylifera L.) leaves as biomonitors of atmospheric metal pollution in arid and semi-arid environments

    International Nuclear Information System (INIS)

    The leaves of date palms were evaluated as a possible biomonitor of heavy metal contamination in Ma'an city, Jordan. Concentrations of (Fe), (Pb), (Zn), (Cu), (Ni), and (Cr) were determined in washed and unwashed leaves and soil samples collected from different sites with different degrees of metal contamination (urban, suburban, industrial, highway and rural sites); separate leaves were taken from outside the city to be used as a control sample. Samples collected from industrial sites were found to have high concentrations of all metals except those of Cu, Ni and Pb, which were found at high levels in the highway site samples which is associated with the road traffic. The difference between unwashed and washed samples showed that metal pollutants exist as contaminants, particularly Pb, Zn and Ni, which varied in concentration, depending on the source of the metal. - Highlights: → High metal concentration in plant samples and roadside soil was due to the heavy traffic. → The mean concentrations (C) were in the order: CFe > CPb > CZn > CNi > CCu > CCr. → Difference between unwashed and washed samples showed that pollutants exist as contaminants. - Date palm (Phoenix dactylifera L.) leaves can be used as an inexpensive biomonitor of the deposition, accumulation and distribution of heavy metal contamination in arid environments.

  13. Status of Water Levels in Aquifers in the Nacatoch Sand of Southwestern and Northeastern Arkansas and the Tokio Formation of Southwestern Arkansas, February 2005

    Science.gov (United States)

    Schrader, T.P.

    2007-01-01

    The Nacatoch Sand and Tokio Formation aquifers in southwestern Arkansas and the Nacatoch Sand aquifer in northeastern Arkansas are sources of water for industrial, public supply, domestic, and agricultural uses. Potentiometric-surface maps were constructed from water-level measurements made in 60 wells completed in the Nacatoch Sand and 50 wells completed in the Tokio Formation during February 2005. Aquifers in the Nacatoch Sand and Tokio Formation are hereafter referred to as the Nacatoch aquifer and Tokio aquifer, respectively. The direction of ground-water flow in the Nacatoch aquifer in northeastern Arkansas generally is towards the southeast. The potentiometric high is located along the north and northwestern boundaries of the area. The direction of ground-water flow in the Nacatoch aquifer in southwestern Arkansas is towards the south-southeast in Little River, Miller, and Hempstead Counties and to the east-southeast in Nevada and Clark Counties. The potentiometric high is located within the outcrop area in north-central Hempstead County. A cone of depression exists in the Nacatoch aquifer at Hope in southeastern Hempstead County. The direction of ground-water flow in the Tokio aquifer in southwestern Arkansas generally is towards the south or southeast. The potentiometric high is within the outcrop area. An area of artesian flow exists in southeastern Pike, northeastern Hempstead, and northwestern Nevada Counties. One apparent cone of depression might exist northwest of Hope in Hempstead County. In northeastern Arkansas, withdrawals from the Nacatoch aquifer increased by 516 percent from 1965 to 2000. In southwestern Arkansas, withdrawals from Nacatoch aquifer and Tokio aquifer increased by 125 percent and 201 percent, respectively, from 1965 to 1980 and decreased by 93 percent and 80 percent, respectively, from 1980 to 2000. Long-term hydrographs were prepared for 10 wells in the study areas. Changes in water levels in some wells may be associated with

  14. Status of Water Levels in Aquifers in the Nacatoch Sand of Southwestern and Northeastern Arkansas and the Tokio Formation of Southwestern Arkansas, 1999

    Science.gov (United States)

    Schrader, Tony P.

    1999-01-01

    Nacatoch Sand and Tokio Formation aquifers in southwestern Arkansas and the Nacatoch Sand aquifer in northeastern Arkansas are a source of water for industrial, public supply, domestic, and agricultural uses. Potentiometric-surface maps were constructed from water-level measurements made in 59 wells completed in the Nacatoch Sand and 45 wells completed in the Tokio Formation from April through May 1999. The direction of ground-water flow in the aquifer in the Nacatoch Sand in northeastern Arkansas generally is towards the southeast. The potentiometric high is located along the north and northwestern boundaries. The direction of ground-water flow in the aquifer in the Nacatoch Sand in southwestern Arkansas is towards the south-southeast in Little River, Miller, and Hempstead Counties and to the east-southeast in Nevada and Clark Counties. The potentiometric high is located within the outcrop area in north-central Hempstead County. A cone of depression exists in the aquifer in the Nacatoch Sand at Hope in southeastern Hempstead County. The direction of ground-water flow in the aquifer in the Yokio Formation in southwestern Arkansas generally is towards the southeast. The potentiometric high is within the outcrop area. An area of artesian flow exists in southeastern Pike, northeastern Hempstead, and northwestern Nevada Counties. One apparent cone of depression might exist northwest of Hope in Hempstead County. In northeastern Arkansas, withdrawals from the Nacatoch Sand increased by 736 percent from 1965 to 1995. In southwestern Arkansas withdrawals from aquifers in the Nacatoch Sand and Yokio Formation increased by 125 percent and 201 percent, respectively, from 1965 to 1980 and decreased by 78 percent and 63 percent, respectively, from 1980 to 1995. Long-term hydrographs were prepared for 13 wells in the study area. Changes in water levels in some wells may be associated with changes in withdrawals from the respective aquifers.

  15. Influences on the stable oxygen and carbon isotopes in gerbillid rodent teeth in semi-arid and arid environments: Implications for past climate and environmental reconstruction

    Science.gov (United States)

    Jeffrey, Amy; Denys, Christiane; Stoetzel, Emmanuelle; Lee-Thorp, Julia A.

    2015-10-01

    The stable isotope composition of small mammal tissues has the potential to provide detailed information about terrestrial palaeoclimate and environments, because their remains are abundant in palaeontological and archaeological sites, and they have restricted home ranges. Applications to the Quaternary record, however, have been sparse and limited by an acute lack of understanding of small mammal isotope ecology, particularly in arid and semi-arid environments. Here we document the oxygen and carbon isotope composition of Gerbillinae (gerbil) tooth apatite across a rainfall gradient in northwestern Africa, in order to test the relative influences of the 18O/16O in precipitation or moisture availability on gerbil teeth values, the sensitivity of tooth apatite 13C/12C to plant responses to moisture availability, and the influence of developmental period on the isotopic composition of gerbil molars and incisors. The results show that the isotopic composition of molars and incisors from the same individuals differs consistent with the different temporal periods reflected by the teeth; molar teeth are permanently rooted and form around the time of birth, whereas incisors grow continuously. The results indicate that tooth choice is an important consideration for applications as proxy Quaternary records, but also highlights a new potential means to distinguish seasonal contexts. The oxygen isotope composition of gerbil tooth apatite is strongly correlated with mean annual precipitation (MAP) below 600 mm, but above 600 mm the teeth reflect the oxygen isotope composition of local meteoric water instead. Predictably, the carbon isotope composition of the gerbil teeth reflected C3 and C4 dietary inputs, however arid and mesic sites could not be distinguished because of the high variability displayed in the carbon isotope composition of the teeth due to the microhabitat and short temporal period reflected by the gerbil. We show that the oxygen isotope composition of small

  16. Correlations between microbial tetraether lipids and environmental variables in Chinese soils: Optimizing the paleo-reconstructions in semi-arid and arid regions

    Science.gov (United States)

    Yang, Huan; Pancost, Richard D.; Dang, Xinyue; Zhou, Xinying; Evershed, Richard P.; Xiao, Guoqiao; Tang, Changyan; Gao, Li; Guo, Zhengtang; Xie, Shucheng

    2014-02-01

    The bacterial membrane lipid-based continental paleothermometer, the MBT/CBT or MBT‧-CBT proxy (methylation index of branched tetraethers/cyclization of branched tetraethers), results in a large temperature deviation when applied in semiarid and arid regions. Here we propose new calibration models based on the investigation of >100 surface soils across a large climatic gradient, with a particular focus on semiarid and arid regions of China, and apply them to a loess-paleosol sequence. As reported elsewhere, MBT values exhibit a much higher correlation with MAAT than with summer temperature, suggesting a minimal seasonality bias; however, MBT is apparently insensitive to temperature 20 °C. Additional complexities are apparent in alkaline and arid soils, which are characterized by different relationships to climatic parameters than those in the complete Chinese (or global) dataset. For example, MBT and CBT indices exhibit a negative correlation in alkaline and arid soils, in contrast to their positive correlation in acid soils. Moreover, the cyclization ratio of bGDGTs (CBT), previously defined as a proxy for soil pH, is apparently primarily controlled by MAAT in these alkaline soils. Thus, we propose (1) a local Chinese calibration of the MBT-CBT proxy and (2) an alternative temperature proxy for use in semiarid and arid regions based on the fractional abundances of bGDGTs; the latter has a markedly higher determination factor and lower root mean square error in alkaline soils than the Chinese local calibration and is suggested to be preferred for paleotemperature reconstruction in Chinese loess/paleosol sequences. These new bGDGT proxies have been applied to the Weinan Holocene paleosol section of the Chinese Loess Plateau (CLP). The fractional abundance calibration, when applied in the Weinan Holocene paleosol, produces a total Holocene temperature variation of 5.2 °C and a temperature for the topmost sample that is consistent with the modern temperature

  17. INVESTIGATION OF THE GROUNDWATER SUITABILITY FOR IRRIGATION PRACTICES IN AN ARID REGION: CASE STUDY

    Directory of Open Access Journals (Sweden)

    Ahmed Murad

    2014-01-01

    Full Text Available Groundwater is an important source of acceptable water for irrigation in the arid regions and in particular in the United Arab Emirates (UAE. Demand for groundwater is increasing in the UAE due to population growth and significant economic advancement associated with political stability. As agricultural practices are the main land use in Al Hayer area, southeast UAE, majority of extracted groundwater from major aquifer is used to meet the increasing demands of irrigation. This study is aimed to assess the suitability of groundwater in the study area for irrigation practices using classifications of Sodium Adsorption Ratio (SAR, Soluble Sodium Percentage (SSP, Magnesium Adsorption Ratio (MAR as magnesium hazard and Residual Sodium Carbonate (RSC. In addition to that, the quality is assessed using the Total Dissolved Solids (TDS and Electrical Conductivity (EC of collected groundwater samples. Assessing the quality of groundwater in the region will help the decision makers in determining appropriate actions and using the conventional management tools to protect groundwater from the possible contamination. The chemical results indicate that the groundwater of the study area contains excess of Na+ and Mg+2. This is related to the weathering of Oman Mountains which are located to the east of the study area. The data analyses of salinity hazard suggested that about 44% of collected groundwater samples from the entire region are grouped as very high salinity and are not suitable for irrigation and about 56% are grouped as high salinity which is doubtful to be used for irrigation. The calculations of SAR reveal that the groundwater of the study area is good to excellent for crop production. While, the calculated magnesium hazard suggests that all samples are not suitable for irrigation purposes. The SAR-EC plot presents two groups of sampling points. The first group of groundwater can be used for irrigation of most crops in almost all soils, however

  18. Theoretical simulation of small scale psychometric solar water desalination system in semi-arid region

    International Nuclear Information System (INIS)

    Many countries around the world suffer from water scarcity. This is especially true in remote and semi-arid regions in the Middle East and North Africa (MENA) where per capita water supplies decline as populations increase. This paper presents the results of a theoretical simulation of an affordable small scale solar water desalination plant using the psychometric humidification and dehumidification process coupled with an evacuated tube solar collector with an area of about 2 m2. A mathematical model was developed to describe the system's operation. Then a computer program using Simulink Matlab software was developed to provide the governing equations for the theoretical calculations of the humidification and dehumidification processes. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. After the experimental calibration of the mathematical model, a model simulating solar radiation under the climatic conditions in the Middle East region proved that the performance of the system could be improved to produce a considerably higher amount of fresh water, namely up to 17.5 kg/m2 day. This work suggests that utilizing the concept of humidification and dehumidification, a compact water desalination unit coupled with solar collectors would significantly increase the potable water supply in remote area. It could be a unique solution of water shortages in such areas. -- Highlights: • An affordable small scale desalination system is proposed. • A mathematical model of the desalination system is developed and programmed using Matlab Simulink. • The model describes the psychometric process based on humidification and dehumidification. • The model is used in optimal selection of elements and operating conditions for solar desalination system. • The use of solar water desalination contributes significantly to reducing global warming

  19. On evaluating characteristics of the solute transport in the arid vadose zone.

    Science.gov (United States)

    Yu, Zhongbo; Dong, Weiquan; Young, Michael H; Li, Yiping; Yang, Tao

    2014-01-01

    The transport of bromide (Br) under matric heads of 0, -2, -5, and -10 cm using undisturbed soil columns was investigated for understanding the solute transport in arid soils. Undisturbed soil cores were collected at ground surface, directly below where tension infiltrometer measurements were made in the Amargosa Desert, Nevada, United States. Laboratory experiments were conducted by introducing water containing Br tracer into a soil column maintained at steady-state conditions. The observed data of breakthrough curves (BTC) were well fitted to an one-region model, except for the cores at saturation, and a core at the matric head of -5 cm, from which the observed data were better fitted to a two-region model. Fitted pore water velocities with the one-region model ranged from 1.2 to 56.6 cm/h, and fitted dispersion coefficients (D) ranged from 2.2 to 100 cm² /h. Results for the core analyzed with the two-region model indicated that D ranged from 27.6 to 70.9 cm² /h at saturation, and 25.7 cm² /h at the matric head of -5 cm; fraction of mobile water (β) ranged from 0.18 to 0.65, and mass transfer coefficient (ω) ranged from 0.006 to 0.03. In summary, the water fluxes and Br dispersion coefficients at investigated matric heads were very high due to the coarseness of the soils and possibly due to preferential flow pathways. These high water fluxes and Br dispersion coefficients would lead to a higher risk of deeper leaching accumulating nitrate nitrogen to the groundwater, and have significant effects on the desert ecosystem. PMID:23406385

  20. Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

    2005-05-01

    A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4