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Sample records for arid western doe

  1. 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

  2. ENVIRONMENTAL MANAGEMENT SCIENCE PROGRAM PROJECT NUMBER 87016 CO-PRECIPITATION OF TRACE METALS IN GROUNDWATER AND VADOSE ZONE CALCITE: IN SITU CONTAINMENT AND STABILIZATION OF STRONTIUM-90 AND OTHER DIVALENT METALS AND RADIONUCLIDES AT ARID WESTERN DOE SITES

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) weapons complex. In situ containment and stabilization of these contaminants in vadose zones or groundwater is a cost-effective treatment strategy. Our facilitated approach relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal coprecipitation) by increasing groundwater pH and alkalinity (Fujita et al., 2000; Warren et al., 2001). Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation processes are irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from groundwater. The rate at which trace metals are incorporated into calcite is a function of calcite precipitation kinetics, adsorption interactions between the calcite surface and the trace metal in solution (Zachara et al., 1991), solid solution properties of the trace metal in calcite (Tesoriero and Pankow, 1996), and also the surfaces upon which the calcite is precipitating. A fundamental understanding of the coupling of calcite precipitation and trace metal partitioning, and how this occurs in aquifers and vadose environments is lacking. This report summarizes work undertaken during the second year of this project

  3. Salinization of groundwater in arid and semi-arid zones: an example from Tajarak, western Iran

    Science.gov (United States)

    Jalali, Mohsen

    2007-06-01

    Study of the groundwater samples from Tajarak area, western Iran, was carried out in order to assess their chemical compositions and suitability for agricultural purposes. All of the groundwaters are grouped into two categories: relatively low mineralized of Ca-HCO3 and Na-HCO3 types and high mineralized waters of Na-SO4 and Na-Cl types. The chemical evolution of groundwater is primarily controlled by water-rock interactions mainly weathering of aluminosilicates, dissolution of carbonate minerals and cation exchange reactions. Calculated values of pCO2 for the groundwater samples range from 2.34 × 10-4 to 1.07 × 10-1 with a mean value of 1.41 × 10-2 (atm), which is above the pCO2 of the earth’s atmosphere (10-3.5). The groundwater is oversaturated with respect to calcite, aragonite and dolomite and undersaturated with respect to gypsum, anhydrite and halite. According to the EC and SAR the most dominant classes (C3-S1, C4-S1 and C4-S2) were found. With respect to adjusted SAR (adj SAR), the sodium (Na+) content in 90% of water samples in group A is regarded as low and can be used for irrigation in almost all soils with little danger of the development of harmful levels of exchangeable Na+, while in 40 and 37% of water samples in group B the intensity of problem is moderate and high, respectively. Such water, when used for irrigation will lead to cation exchange and Na+ is adsorbed on clay minerals while calcium (Ca2+) and magnesium (Mg2+) are released to the liquid phase. The salinity hazard is regarded as medium to high and special management for salinity control is required. Thus, the water quality for irrigation is low, providing the necessary drainage to avoid the build-up of toxic salt concentrations.

  4. Early Pleistocene climate in western arid central Asia inferred from loess-palaeosol sequences

    Science.gov (United States)

    Wang, Xin; Wei, Haitao; Taheri, Mehdi; Khormali, Farhad; Danukalova, Guzel; Chen, Fahu

    2016-02-01

    Arid central Asia (ACA) is one of the most arid regions in the mid-latitudes and one of the main potential dust sources for the northern hemisphere. The lack of in situ early Pleistocene loess/dust records from ACA hinders our comprehensive understanding of the spatio-temporal record of aeolian loess accumulation and long term climatic changes in Asia as a whole. Here, we report the results of sedimentological, chronological and climatic studies of early Pleistocene loess-palaeosol sequences (LPS) from the northeastern Iranian Golestan Province (NIGP) in the western part of ACA. Our results reveal that: 1) Accumulation of loess on the NIGP commenced at ~2.4-1.8 Ma, making it the oldest loess known so far in western ACA; 2) the climate during the early Pleistocene in the NIGP was semi-arid, but wetter, warmer, and less windy than during the late Pleistocene and present interglacial; 3) orbital-scale palaeoclimatic changes in ACA during the early Pleistoceneare in-phase with those of monsoonal Asia, a relationship which was probably related to the growth and decay of northern hemisphere ice sheets.

  5. 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.

  6. Variability of atmospheric carbonyl sulfide at a semi-arid urban site in western India.

    Science.gov (United States)

    Mallik, Chinmay; Chandra, Naveen; Venkataramani, S; Lal, Shyam

    2016-05-01

    Atmospheric carbonyl sulfide (COS) is a major precursor for sulfate aerosols that play a critical role in climate regulation. Recent studies have highlighted the importance of COS measurements as a reliable means to constrain biospheric carbon assimilation. In a scenario of limited availability of COS data around the globe, we present gas-chromatographic measurements of atmospheric COS mixing ratios over Ahmedabad, a semi-arid, urban region in western India. These measurements, being reported for the first time over an Indian site, enable us to understand the diurnal and seasonal variation in atmospheric COS with respect to its natural, anthropogenic and photochemical sources and sinks. The annual mean COS mixing ratio over Ahmedabad is found to be 0.83±0.43ppbv, which is substantially higher than free tropospheric values for the northern hemisphere. Inverse correlation of COS with soil and skin temperature, suggests that the dry soil of the semi-arid study region is a potential sink for atmospheric COS. Positive correlations of COS with NO2 and CO during post-monsoon and the COS/CO slope of 0.78pptv/ppbv reveals influence of diesel combustion and tire wear. The highest concentrations of COS are observed during pre-monsoon; COS/CO2 slope of 44.75pptv/ppmv combined with information from air mass back-trajectories reveal marshy wetlands spanning over 7500km(2) as an important source of COS in Ahmedabad. COS/CO2 slopes decrease drastically (8.28pptv/ppmv) during post-monsoon due to combined impact of biospheric uptake and anthropogenic emissions. PMID:26907740

  7. Chloride mass-balance method for estimating ground water recharge in arid areas: Examples from western Saudi Arabia

    Science.gov (United States)

    Bazuhair, A.S.; Wood, W.W.

    1996-01-01

    The chloride mass-balance method, which integrates time and aerial distribution of ground water recharge, was applied to small alluvial aquifers in the wadi systems of the Asir and Hijaz mountains in western Saudi Arabia. This application is an extension of the method shown to be suitable for estimating recharge in regional aquifers in semi-arid areas. Because the method integrates recharge in time and space it appears to be, with certain assumptions, particularly well suited for and areas with large temporal and spatial variation in recharge. In general, recharge was found to be between 3 to 4% of precipitation - a range consistent with recharge rates found in other arid and semi-arid areas of the earth.

  8. Patterns of ant (Hymenoptera: Formicidae) richness and relative abundance along an aridity gradient in Western Venezuela.

    Science.gov (United States)

    Pérez-Sánchez, A J; Lattke, J E; Viloria, A L

    2013-04-01

    In xeric ecosystems, ant diversity response to aridity varies with rainfall magnitude and gradient extension. At a local scale and with low precipitation regimes, increased aridity leads to a reduction of species richness and an increased relative abundance for some ant species. In order to test this pattern in tropical environments, ant richness and relative abundance variation were evaluated along 35 km of an aridity gradient in the Araya Peninsula, state of Sucre, Venezuela. Three sampling stations comprising five transects each were set up. Pitfall traps and direct collecting from vegetation were assessed per transect. Overall, 52 species, 23 genera, and 7 subfamilies of ants were recorded in the peninsula. The total number of species and genera recorded by both sampling stations and transects decreased linearly with increasing aridity. Total relative abundance was highest in the most arid portion of the peninsula, with Crematogaster rochai (Forel) and Camponotus conspicuus zonatus (Emery) (Hymenoptera: Formicidae) being the numerically dominant species. Spatial and multivariate analyses revealed significant changes in ant composition every 11 km of distance, and showed a decrease of ant diversity with the increase of harsh conditions in the gradient. Here, we discuss how local geographic and topographic features of Araya originate the aridity gradient and so affect the microhabitat conditions for the ant fauna. PMID:23949745

  9. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Stronthium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Robert W.; Fujita, Yoshiko

    2007-11-07

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers’ exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating the linkage between urea hydrolysis and calcite precipitation in field and laboratory experiments **Observing strontium incorporation into calcite precipitate by urea hydrolyzers with higher distribution coefficient than in abiotic **Developing and applying molecular methods for characterizing microbial urease activity in groundwater including a quantitative PCR method for enumerating ureolytic bacteria **Applying the suite of developed molecular methods to assess the feasibility of the

  10. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating the linkage between urea hydrolysis and calcite precipitation in field and laboratory experiments **Observing strontium incorporation into calcite precipitate by urea hydrolyzers with higher distribution coefficient than in abiotic **Developing and applying molecular methods for characterizing microbial urease activity in groundwater including a quantitative PCR method for enumerating ureolytic bacteria **Applying the suite of developed molecular methods to assess the feasibility of the

  11. Facilitation contributes to Mediterranean woody plant diversity but does not shape the diversity-productivity relationship along aridity gradients.

    Science.gov (United States)

    Rey, Pedro J; Alcántara, Julio M; Manzaneda, Antonio J; Sánchez-Lafuente, Alfonso M

    2016-07-01

    The diversity-productivity relationship (humped-back model (HBM)) and the stress-gradient (SGH) hypotheses may be connected when productivity is limited primarily by aridity. We analytically connect both hypotheses and assess the contribution of facilitation to woody plant richness along the aridity gradient of the Western Mediterranean floristic region. We monitored regeneration niches of woody plants, obtaining rarefied species richness and plant relative interaction indices in 54 forests and scrublands in a 1750-km geographical range across Spain, Morocco and the Canary Islands. We verified the monotonic increase in facilitation with aridity postulated by SGH and the humped-shape pattern of species richness expected from HBM, which became manifest after expanding the aridity gradient or crossing vegetation types. Along the gradient, interaction balance turned into facilitation earlier in forest than in scrublands. The effects of aridity and interaction balance on species diversity were additive rather than interdependent. Facilitation is an important driver of woody species richness at macroecological scales because it added up to diversity in most sites, with enhanced contribution with increased stress. The HBM was not shaped by species interactions. Results suggest that facilitation may act in Mediterranean vegetation buffering against critical transitions between states allowing woody plant communities to cope with the rise in aridity expected with global warming. PMID:26959084

  12. When does colonisation of a semi-arid hillslope generate vegetation patterns?

    Science.gov (United States)

    Sherratt, Jonathan A

    2016-07-01

    Patterned vegetation occurs in many semi-arid regions of the world. Most previous studies have assumed that patterns form from a starting point of uniform vegetation, for example as a response to a decrease in mean annual rainfall. However an alternative possibility is that patterns are generated when bare ground is colonised. This paper investigates the conditions under which colonisation leads to patterning on sloping ground. The slope gradient plays an important role because of the downhill flow of rainwater. One long-established consequence of this is that patterns are organised into stripes running parallel to the contours; such patterns are known as banded vegetation or tiger bush. This paper shows that the slope also has an important effect on colonisation, since the uphill and downhill edges of an isolated vegetation patch have different dynamics. For the much-used Klausmeier model for semi-arid vegetation, the author shows that without a term representing water diffusion, colonisation always generates uniform vegetation rather than a pattern. However the combination of a sufficiently large water diffusion term and a sufficiently low slope gradient does lead to colonisation-induced patterning. The author goes on to consider colonisation in the Rietkerk model, which is also in widespread use: the same conclusions apply for this model provided that a small threshold is imposed on vegetation biomass, below which plant growth is set to zero. Since the two models are quite different mathematically, this suggests that the predictions are a consequence of the basic underlying assumption of water redistribution as the pattern generation mechanism. PMID:26547308

  13. Criteria for greater confinement of radioactive wastes at arid western sites

    Energy Technology Data Exchange (ETDEWEB)

    Card, D.H.; Hunter, P.H.; Adam, J.A.; White, R.B.

    1981-05-01

    This document provides a set of criteria and standards for greater confinement disposal (CCD) of low-level waste as an alternative to shallow land burial or deep geologic disposal for certain types of waste. The criteria and standards are discussed relative to seven major areas: radiation exposure protection, characterization of waste, transportation and handling, site selection, engineering, general facility requirements, and administration. The document addresses the objectives or goals of burial at intermediate depths to provide greater confinement, and its advantages and disadvantages compared to shallow land burial. Additionally, the document describes a generic greater confinement disposal facility (GCDF), and discusses as well as evaluates the various interrelating factors which must be considered in the selection of a viable site and in the development of GCDF design and performance criteria. Methods are developed for evaluating and ranking the importance of the factors based on health and safety, their potential impact on cost, and the uncertainty and/or difficulty in measurement and control of the factors. It also provides the methodology and analysis used to determine the various site-specific waste concentration acceptance standards (in the form of area disposal concentration limits) as well as design and engineering standards. It also illustrates the methodology used to determine the optimal or preferred depth of disposal under expected arid site conditions and alternative wet or irrigated site conditions. In addition, an example calculation demonstrates the application of the waste area concentration limits at an arid or humid GDF in determining the allowable waste inventory capacity of a particular site and the loading capacity of a waste disposal cell.

  14. Environmental gradients across wetland vegetation groups in the arid slopes of Western Alborz Mountains, N. Iran

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    Asghar Kamrani

    2011-04-01

    Full Text Available Mountain wetlands are unique ecosystems in the arid southern slopes of Alborz range, the second largest range in Iran. The spatial distribution characteristics of wetland vegetation in the arid region of the Alborz and the main factors affecting their distributional patterns were studied. A classification of vegetation and ecological characteristics were carried out using data extracted from 430 relevés in 90 wetland sites. The data were analyzed using Two Way Indicator Species Analysis (TWINSPAN and detrended correspondence analysis (DCA. The wetland vegetation of Alborz Mountain was classified into four large groups. The first vegetation group was calcareous rich vegetation, mainly distributed in the river banks and characterized by helophytes such as Bolboschoenus affinis as indicator species. The second group was saline transitional vegetation, distributed in the ecotone areas and dominated by Phragmites australis. The third vegetation group is wet meadow vegetation which mainly consists of geophytes, endemic and Irano-Turanian species, distributed in the higher altitudes. This vegetation is mainly characterized by indicator species such as Carex orbicularis, high level concentration of Fe2+ and percentage of organic matter in the soil. The fourth vegetation group is aquatic vegetation, distributed in the lakeshores. The aquatic group species are mainly hydrophytic such as Batrachium trichophyllum. The TWINSPAN vegetation groups could be also recognized in the DCA graphs and ecologically differentiated by ANOVA of studied variables. Four vegetation groups can be differentiated on two first axes of indirect ordination. There is a gradient of pH, EC and organic matter associated with altitude on the DCA diagram. Correlation analysis between the axes of DCA and environmental factors shows that altitude, soil texture and other dependant environmental variables (e.g. pH are the main environmental factors affecting the distribution of wetland

  15. Criteria for greater confinement of radioactive wastes at arid western sites

    International Nuclear Information System (INIS)

    This document provides a set of criteria and standards for greater confinement disposal (CCD) of low-level waste as an alternative to shallow land burial or deep geologic disposal for certain types of waste. The criteria and standards are discussed relative to seven major areas: radiation exposure protection, characterization of waste, transportation and handling, site selection, engineering, general facility requirements, and administration. The document addresses the objectives or goals of burial at intermediate depths to provide greater confinement, and its advantages and disadvantages compared to shallow land burial. Additionally, the document describes a generic greater confinement disposal facility (GCDF), and discusses as well as evaluates the various interrelating factors which must be considered in the selection of a viable site and in the development of GCDF design and performance criteria. Methods are developed for evaluating and ranking the importance of the factors based on health and safety, their potential impact on cost, and the uncertainty and/or difficulty in measurement and control of the factors. It also provides the methodology and analysis used to determine the various site-specific waste concentration acceptance standards (in the form of area disposal concentration limits) as well as design and engineering standards. It also illustrates the methodology used to determine the optimal or preferred depth of disposal under expected arid site conditions and alternative wet or irrigated site conditions. In addition, an example calculation demonstrates the application of the waste area concentration limits at an arid or humid GDF in determining the allowable waste inventory capacity of a particular site and the loading capacity of a waste disposal cell

  16. ASSESSMENT OF THE PRESENCE OF Toxocara EGGS IN SOILS OF AN ARID AREA IN CENTRAL-WESTERN ARGENTINA

    Directory of Open Access Journals (Sweden)

    María Viviana Bojanich

    2015-02-01

    Full Text Available With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

  17. Improving seedling germination and emergence of legumes native to the semi-arid western USA

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    Basalt milkvetch (Astragalus filipes), western prairie clover (Dalea ornata), and Searl's prairie clover (Dalea searlsiae) are non-toxic to wildlife, have high forage quality, are adapted to climates with low rainfall (200-350mm), and have potential for agronomic seed production. However, these thr...

  18. Evolution of a Permian Arid Lake System, Upper Pedra de Fogo Formation, Western Border of the Parnaiba Basin

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    Luiz Saturnino de Andrade

    2014-12-01

    Full Text Available Stratigraphic and facies analysis in the Filadélfia region, TO, BR, at the western of the Parnaíba Basin, allowed redefine the paleoenvironment of the upper portion of the Pedra de Fogo Formation of Permian age. The studied deposits are a series of approximately 100 m thick, predominantly siliciclastic, with subordinate carbonates and evaporites, where were defined 21 sedimentary facies that could be grouped into six facies associations (AF: AF1 Lacustrine with ephemeral river deposits; AF2 Storm wave-influenced lake deposits; AF3 Continental sabkha deposits; AF4 Central lake deposits; AF5 Eolian dunes field deposits; and AF6 Lake/oasis deposits with inunditos. These associations indicate that during Permian, an extensive lacustrine arid system developed adjacent to eolian dunes fields and continental sabkha, as well as with contributions from ephemeral rivers. Fluvial incursions into lakes propitiated the formation of suspension lobes and sheet flows (AF1. Sabkha plains (AF3 were formed in the marginal portions of the lake that eventually were influenced by storms waves (AF2, while central zone were site of intense pelitic deposition (AF4. The low supply of eolian sand in this system resulted in the formation of restricted dune fields (AF5, with development of interdune lakes (oasis, where proliferating giant ferns, sporadically flooded by ephemeral rivers (AF6. The facies associations data, corroborated by the paleogeography of the region during the Late Permian, indicate that settling of the top part of the Pedra de Fogo Formation was laid during a hot and arid climate.

  19. Using trait-based approaches to study phytoplankton seasonal succession in a subtropical reservoir in arid central western Argentina.

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    Beamud, S G; León, J G; Kruk, C; Pedrozo, F; Diaz, M

    2015-05-01

    The application of trait-based approaches has become a widely applied tool to analyse community assembly processes and dynamics in phytoplankton communities. Its advantages include summarizing information of many species without losing essentials of the main driving processes. Here, we used trait-based approaches to study phytoplankton temporal succession in a subtropical reservoir. We applied a combined approach including morphological traits (i.e. volume, surface) and functional clustering of species (morphology-based functional groups (MBFG) and Reynolds' groups) and related the clustering of species with the environment. We found that this reservoir is characterized by a low richness and a bimodal distribution of phytoplankton biomass. Taxonomic and functional classifications were coincident, and the dominant species and groups biomasses were explained by the same group of variables. For instance, group X₂, MBFG V and Carteria sp. biomasses were explained by: pH, Secchi disk depth, N-NH₄; while group B, MBFG VI and Cyclotella ocellata biomasses were explained by stability of the water column, incident solar radiation, Secchi disk depth and N-NH4. From our results, we state that functional and taxonomic classifications are complementary rather than opposed approaches, and their specific uses depend exclusively on the aim of the study and the characteristics of the environment under evaluation. Our work is the first description of phytoplankton dynamics in a reservoir in the arid central western Argentina (Cuyo region). PMID:25893768

  20. Detection and prediction of land cover changes using Markov chain model in semi-arid rangeland in western Iran.

    Science.gov (United States)

    Fathizad, Hassan; Rostami, Noredin; Faramarzi, Marzban

    2015-10-01

    The study of changes and destruction rate in the previous years as well as the possibility of prediction of these changes in the following years has a key role in optimal planning, controlling, and restricting non-normative changes in the future. This research was approached to detecting land use/cover changes (1985-2007) and to forecast the changes in the future (2021) use of multitemporal satellite imagery in semi-arid area in western Iran. A supervised classification of multilayer perceptron (MLP) was applied for detecting land use changes. The study area was classified into five classes, those of forest, rangeland, agriculture, residential, and barren lands. The change detection analysis indicated a decreasing trend in forest cover by 30.42%, while other land uses were increased during 1985 to 2007. The land use changes were predicted using Markov chain model for 2021. The model was calibrated by comparing the simulated map with the real detected classes of land cover in 2007. Then, for further model processing, an acceptable accuracy at 83% was achieved between them. Finally, land use changes were predicted by using transition matrix derived from calibrated approach. The findings of this study demonstrate a rapid change in land use/cover for the coming years. Transforming the forest into other land uses especially rangeland and cropland is the main land cover changes in the future. Therefore, the planning of protection and restoration of forest cover should be an essential program for decision-makers in the study area. PMID:26373304

  1. Carbonaceous aerosol over semi-arid region of western India: Heterogeneity in sources and characteristics

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    Sudheer, A. K.; Aslam, M. Y.; Upadhyay, M.; Rengarajan, R.; Bhushan, R.; Rathore, J. S.; Singh, S. K.; Kumar, S.

    2016-09-01

    Carbonaceous species (elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC)) and water-soluble inorganic species (Na+, NH4+, K+, Ca2 +, Mg2 +, Cl-, NO3-, SO42 -) in PM10 and PM2.5 from Ahmedabad and Jodhpur (urban and semi-urban locations, respectively) in western India were measured during May-September, 2011. Stable isotope composition of carbonaceous aerosol (δ13C of TC) in PM10 samples was also determined. Average EC concentration in PM10 at Ahmedabad was 1 μg m- 3 (range: 0.34 to 3.4 μg m- 3), almost 80% of which remained in PM2.5. Similarly, 70% of EC in PM10 (average: 0.9 μg m- 3) resided in PM2.5 at Jodhpur. Average OC concentration at Ahmedabad was 6.4 μg m- 3 and ~ 52% of this was found in PM2.5. On the contrary, OC concentration at Jodhpur was 40 μg m- 3, 80% of which was found in coarse particles contributing substantially to aerosol mass. δ13C of TC (average: - 27.5‰, range: - 29.6 to - 25.8‰) along with WSOC/EC ratio shows an increasing trend at Jodhpur suggesting the possibility of aging of aerosol, since aging results in enrichment of heavier isotope. OC and WSOC show significant correlations with K+ and not with EC, indicating biogenic origin of OC. Different size distributions are also exhibited by WSOC at the two stations. On the other hand, δ13C exhibits an inverse trend with sea-salt constituents at Ahmedabad, indicating the influence of air masses transported from the western/south-western region on carbonaceous aerosol. These results suggest that a strong heterogeneity exists in the sources of carbonaceous aerosol over this region and potential sources of non-combustion emissions such as bio-aerosol that need further investigation.

  2. Absent otoacoustic emissions predict otitis media in young Aboriginal children: A birth cohort study in Aboriginal and non-Aboriginal children in an arid zone of Western Australia

    OpenAIRE

    Stokes Annette; Finucane Janine; Elsbury Dimity; Jacoby Peter; Weeks Sharon; Lehmann Deborah; Monck Ruth; Coates Harvey

    2008-01-01

    Abstract Background Otitis media (OM) is the most common paediatric illness for which antibiotics are prescribed. In Australian Aboriginal children OM is frequently asymptomatic and starts at a younger age, is more common and more likely to result in hearing loss than in non-Aboriginal children. Absent transient evoked otoacoustic emissions (TEOAEs) may predict subsequent risk of OM. Methods 100 Aboriginal and 180 non-Aboriginal children in a semi-arid zone of Western Australia were followed ...

  3. Non formal mechanisms for public water allocation and the ineffectiveness of law in arid western Argentina

    Directory of Open Access Journals (Sweden)

    Liber Martin

    2015-04-01

    Full Text Available This work analyzed the informal mechanisms of public water allocation and reallocation in western Argentina from a holistic conception of law. The paper refers to informal uses, its logical but ineffective repression and the continuous regularization processes from a non experimental observational method based on the use of qualitative strategies. The research work focused on the operation of water allocation mechanisms and management practices developed in the absence of law and against the law, at both the delivery and regulatory levels. The findings highlight the tensions and contradictions of these mechanisms under the formal legal system, demonstrating the crisis of both effectiveness and legitimacy of the law and the State in managing public waters.

  4. 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.

  5. 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.

  6. 10 CFR 905.22 - How does Western periodically evaluate customer actions?

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false How does Western periodically evaluate customer actions... Resource Planning § 905.22 How does Western periodically evaluate customer actions? (a) Periodic review of customer actions. Western will periodically evaluate customer actions to determine whether they...

  7. Vulnerability of riparian ecosystems to elevated CO2 and climate change in arid and semiarid western North America

    Science.gov (United States)

    Perry, Laura G.; Andersen, Douglas C.; Reynolds, Lindsay V.; Nelson, S. Mark; Shafroth, Patrick B.

    2012-01-01

    Riparian ecosystems, already greatly altered by water management, land development, and biological invasion, are being further altered by increasing atmospheric CO2 concentrations ([CO2]) and climate change, particularly in arid and semiarid (dryland) regions. In this literature review, we (1) summarize expected changes in [CO2], climate, hydrology, and water management in dryland western North America, (2) consider likely effects of those changes on riparian ecosystems, and (3) identify critical knowledge gaps. Temperatures in the region are rising and droughts are becoming more frequent and intense. Warmer temperatures in turn are altering river hydrology: advancing the timing of spring snow melt floods, altering flood magnitudes, and reducing summer and base flows. Direct effects of increased [CO2] and climate change on riparian ecosystems may be similar to effects in uplands, including increased heat and water stress, altered phenology and species geographic distributions, and disrupted trophic and symbiotic interactions. Indirect effects due to climate-driven changes in streamflow, however, may exacerbate the direct effects of warming and increase the relative importance of moisture and fluvial disturbance as drivers of riparian ecosystem response to global change. Together, climate change and climate-driven changes in streamflow are likely to reduce abundance of dominant, native, early-successional tree species, favor herbaceous species and both drought-tolerant and late-successional woody species (including many introduced species), reduce habitat quality for many riparian animals, and slow litter decomposition and nutrient cycling. Climate-driven changes in human water demand and associated water management may intensify these effects. On some regulated rivers, however, reservoir releases could be managed to protect riparian ecosystem. Immediate research priorities include determining riparian species' environmental requirements and monitoring riparian

  8. Patterns of glaciation and topographic hypsometry across semi-arid western Himalayan-Tibetan orogen (Invited)

    Science.gov (United States)

    Dortch, J.; Hughes, P.; Owen, L. A.; Murari, M. K.; Caffee, M. W.

    2013-12-01

    It has been hypothesized that the reduction of mountain glacier extent throughout late Quaternary glacial cycles may reflect adjustment of topographic hypsometry and lowering of accumulation area via glacial erosion. The Himalayan-Tibetan orogen represents a good test case due to high relief, fast rates of erosion, and recently developed regional glacial chronologies. In particular, analysis of all terrestrial cosmogenic nuclide ages of moraines in the drylands of the western Himalayan-Tibetan orogen show 16 regional glacial stages extending back >300 ka; stages older than the global Last Glacial Maximum (gLGM) broadly correlate with strong monsoons, while younger stages correlate with northern hemisphere climatic events. These patterns suggest that frequent glacial advances are driven by mid-latitude westerlies within each glacial cycle, but that each cycle is punctuated by more extensive advances driven by the monsoon. This raises the question of which style of glaciation has the greatest effect on the shaping and incision of topography: frequent, less-extensive variations in glaciation, or infrequent more-extensive advances (the latter being akin to punctuated equilibrium)? To investigate this question, changes in glacier position based on moraines and climatic proxies are used to model changes in equilibrium line altitude (ELA), which is then compared to topographic hypsometry in catchments were the glacial buzzsaw hypothesis has been previously invoked. The loss in resolution due to the decrease in moraine preservation through time must be accounted for. Thus, the MIS curve and monsoon index are combined to fit to the regional chronology with the view that ages represents the minimum age of deglaciation. A best fit curve is used as a proxy for glacial extent to estimate higher-frequency fluctuations for the pre-gLGM portion of the regional chronology. ELAs are then calculated for selected glaciers at various extents to enable the determination of the average

  9. Vegetation and climate history in arid western China during MIS2: New insights from pollen and grain-size data of the Balikun Lake, eastern Tien Shan

    Science.gov (United States)

    Zhao, Yongtao; An, Cheng-Bang; Mao, Limi; Zhao, Jiaju; Tang, Lingyu; Zhou, Aifeng; Li, Hu; Dong, Weimiao; Duan, Futao; Chen, Fahu

    2015-10-01

    Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use high-resolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during MIS2. Our results suggest that: 1) the regional vegetation around Balikun was mainly dominated by desert and/or desert-steppe, and Balikun Lake was relatively shallow and experienced high aeolian input during MIS2; 2) distinctive runoff from mountain glacial meltwater in the eastern parts of the Balikun basin caused a high relative abundance of Artemisia pollen during the LGM (26.5-19.2 cal kyr BP), while simultaneously the desert areas expanded as indicated by the high abundance of desert shrubs (e.g., Elaeagnaceae, Rhamnaceae, Hippophae). This cold and dry LGM climate triggered a substantial lowering of lake level; 3) an extremely cold and dry climate prevailing from 17.0 to 15.2 cal kyr BP, correlated with Heinrich event 1 (H1), would explain the low vegetation cover found then; and 4) the warm and humid Bølling/Allerød interstadial (BA: ca. 15-ca. 13 cal kyr BP) is clearly recorded in the Balikun region by the development of wetland herb communities (e.g., Poaceae, Cyperaceae, Typha), and the lake level rose due to increased runoff. Our results challenge the traditional view of cold and wet climatic conditions and high lake levels in arid western China during the LGM, and we propose that changes in local temperature modulated by July insolation was an indispensable factor in triggering vegetation evolution in the Balikun region during MIS2.

  10. Temporal limits to the archaeological record in arid western NSW, Australia : lessons from OSL and radiocarbon dating of hearths and sediments

    International Nuclear Information System (INIS)

    The Western NSW Archaeology Program (WNSWAP) has been investigating surface scatters of Aboriginal stone artefacts and associated heat-retainer hearths in arid northwestern NSW, Australia, since 1995. The research combines new methods for documenting and analysing stone artefact scatters with an understanding of geomorphic landscape dynamics to seek insights into spatial and temporal patterns of Aboriginal occupation of the arid margin of Australia during the Late Holocene. The temporal dimension is dealt with in two ways: by radiocarbon determinations on charcoal from the remains of heat-retainer hearths associated with the artefact scatters, and by using optically simulated luminescence (OSL) and radiocarbon determinations from valley fill sediments to develop a chronology of landscape evolution of the valleys in which the artefacts and hearths are found. The heat-retainer hearths produced a record of just less than 2000 years of activity within the valley of Stud Creek, a 30 square km catchment in Sturt National Park. However, the record is discontinuous, with a gap in heat-retainer hearth construction of 200-400 years occurring between about 800 and 1100 y BP. Examination of patterns of erosion and deposition at the places where the hearths were found, and Bayesian statistical analysis of the radiocarbon determinations, demonstrates that this gap is real and not an artefact of the survey protocol. A discontinuous record is also evident when the sediments that comprise the valley fill upon which the hearths and stone artefact scatters are currently lying are examined. Five major sedimentary units can be identified, providing a record of depositional episodes ranging from modern or post-European back to the Late Pleistocene (about 70,000 years). But, in contrast to the record from the remains of the heat-retainer hearths, erosion is the major determinant of the temporal pattern of landscape change that can be reconstructed from this record. Gaps of up to 10

  11. Potential of Native Shrubs Haloxylon salicornicum and Calligonum Polygonoides for Restoration of Degraded Lands in Arid Western Rajasthan, India

    Science.gov (United States)

    Rathore, V. S.; Singh, J. P.; Bhardwaj, S.; Nathawat, N. S.; Kumar, Mahesh; Roy, M. M.

    2015-01-01

    Shrub-induced soil property spatial heterogeneity is common in arid and semi-arid ecosystems and aids desertified land restoration. However, the effectiveness of this technique may rely on the plant species used and the habitat conditions present. To assess the degree to which planting two native species, Haloxylon salicornicum and Calligonum polygonoides, facilitates degraded land restoration, soil and herbaceous plant community properties were measured 7 years after planting. Soil samples were extracted at two depths (0-5 and 5-20 cm) from three sub-habitats, i.e., under the shrub canopy, from alleys between shrubs and from the open area. Shrub planting increased the quantity of silt + clay content (30-39 %); enhanced water holding capacities (24-30 %); increased the levels of organic carbon (48-69 %), available nitrogen (31-47 %), available phosphorus (32-41 %), and electrical conductivity (21-33 %); and decreased the pH (7-12 %) and bulk density levels (5-6 %) in the surface layer of soils beneath the canopy. Soil property changes were more significant at the surface (0-5 cm) than in the deeper layer (5-20 cm), and were more pronounced under H. salicornicum than under C. polygonoides. Furthermore, the density and biomass levels of herbaceous plants were 1.1 to 1.2 and 1.4 to 1.6 times greater, respectively, in the shrub alleys than in open area. H. salicornicum induced more robust soil amelioration and herbaceous plant facilitative properties than did C. polygonoides. Artificially planting these shrubs may thus be employed to restore degraded areas of arid regions.

  12. Contaminant migration at two low-level radioactive waste sites in arid western United States - a review

    International Nuclear Information System (INIS)

    Contamination of the unsaturated zone and ground water at the Beatty, Nevada and Richland, Washington low-level radioactive waste sites shows that pathways exist for rapid lateral and vertical migration of contaminants through unconsolidated clastic sediments that comprise the 100 m-thick unsaturated zones of those arid disposal sites. Disposal of liquid wastes at the Beatty site until 1975 may have contributed to rapid migration of contaminants, but negligible amounts of liquid wastes reportedly were disposed at the Richland LLRW site and similar problems of contaminant migration exist. Pathways for vertical migration in the unsaturated zone include fractures and, at Richland, clastic dikes; lateral migration pathways likely are facies-controlled. Disturbance of the disposal sites contributed to increased infiltration of the unlined waste trenches after closure; simulations that used Beatty sample data show dramatic increases in recharge with disturbances necessary to develop the site. Because neither and arid climate nor presence of a thick unsaturated zone offer effective barriers to ground-water contamination, reliance on those factors at proposed sites such as Ward Valley, California and elsewhere is unwarranted. (orig.)

  13. How Western Does Business: An Explanation of Western's Products and Services

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-01

    The mission of the Western Area Power Administration is to market and deliver reliable, renewable, cost-based hydroelectric power and related services. This guide provides an overview of Western’s history and how Western carries out that mission and provides electrical, transmission and ancillary services. It also discusses how we develop plans for marketing our most valuable resources—long-term firm capacity and energy.

  14. Environmental controls on soil organic carbon and nitrogen stocks in the high-altitude arid western Qinghai-Tibetan Plateau permafrost region

    Science.gov (United States)

    Wu, Xiaodong; Zhao, Lin; Fang, Hongbing; Zhao, Yuguo; Smoak, Joseph M.; Pang, Qiangqiang; Ding, Yongjian

    2016-01-01

    While permafrost in the circum-Artic has great influence on soil organic carbon (SOC) and total nitrogen (TN) stocks, this might not be the case in low-latitude arid permafrost regions. We test this hypothesis in the western Qinghai-Tibetan Plateau (QTP) permafrost region. Fifty-nine soil profiles were analyzed to examine the SOC and TN distribution and the controlling factors in western QTP, which is a desert steppe ecoregion. Mean stocks of SOC (5.29 kg m-2) and TN (0.56 kg m-2) for the top 200 cm in this area were lower than those of the east QTP and circum-Arctic regions. The SOC and TN stocks under vegetative cover with permafrost conditions were significantly higher than those of desert conditions. The SOC and TN stocks for the layers of different depths were related to the content of clay, silt, and moisture. Although the active layer thickness (ALT) had a significant negative correlation to soil moisture, the ALT explained little or no variance in the SOC and TN stocks. The results showed that in the vast permafrost regions of the western QTP, the SOC and TN stocks are very low, and the main controlling factors for the SOC and TN are soil texture, moisture, and vegetation type. The SOC pool in this area may not be as vulnerable to degradation associated with climate warming and thus not emit greenhouse gases at the same rate as other permafrost regions. The different response of the SOC in this region should be considered in carbon cycling models.

  15. Hydrological Connectivity and Science and Policy Integration Issues for Aquatic Resource Jurisdictional Determinations in a Semi-Arid Region of the Western U.S

    Science.gov (United States)

    Caruso, B. S.

    2012-12-01

    Rivers and streams are becoming increasingly stressed and degraded, and wetlands lost, due to human development and associated management policies and actions that are generally ineffective for aquatic resources protection and restoration. In the semi-arid western U.S., these issues are more severe due to the limited quantity of water and aquatic resources, the magnified role of their ecological services in drier landscapes, and increasing impacts from urbanization and energy development. However, a significant disconnect between policy and science exists that leads to continued degradation of surface waters. Supreme Court decisions and joint Federal agency guidance for determining jurisdiction as 'waters of the US' that can be protected under Clean Water Act Section 404 (permitting discharge of dredged and fill materials into wetlands and other waters) are good examples of this disconnect. The hydrological and ecological connectivity of intermittent and ephemeral streams and wetlands with downstream navigable waters is a critical issue that must be evaluated to determine jurisdiction, but this can be a complex endeavour in semi-arid regions. The hydrological connectivity and key science and policy integration issues for stream and wetland jurisdictional determinations (JDs) were evaluated for a semi-arid region of the western U.S. (Environmental Protection Agency [EPA] Region 8), including much of the Rocky Mountains, Great Plains and Colorado Plateau. The key scientific approaches recommended in the agency guidance were analyzed in detail. An evaluation was performed of a sample of JDs reviewed by EPA Region 8 and their outcomes in terms of aquatic resources that were considered non-jurisdictional. An analysis of stream types and characteristics across the region using available digital spatial analysis tools was performed. A subset of finalized JDs issued by COE was reviewed to analyze the scientific information used to evaluate connectivity to downstream waters

  16. Use of the subsurface thermal regime as a groundwater-flow tracer in the semi-arid western Nile Delta, Egypt

    Science.gov (United States)

    Salem, Zenhom E.; Bayumy, Dina A.

    2016-06-01

    Temperature profiles from 25 boreholes were used to understand the spatial and vertical groundwater flow systems in the Western Nile Delta region of Egypt, as a case study of a semi-arid region. The study area is located between the Nile River and Wadi El Natrun. The recharge areas, which are located in the northeastern and the northwestern parts of the study area, have low subsurface temperatures. The discharge areas, which are located in the western (Wadi El Natrun) and southern (Moghra aquifer) parts of the study area, have higher subsurface temperatures. In the deeper zones, the effects of faults and the recharge area in the northeastern direction disappear at 80 m below sea level. For that depth, one main recharge and one main discharge area are recognized. The recharge area is located to the north in the Quaternary aquifer, and the discharge area is located to the south in the Miocene aquifer. Two-dimensional groundwater-flow and heat-transport models reveal that the sealing faults are the major factor disturbing the regional subsurface thermal regime in the study area. Besides the main recharge and discharge areas, the low permeability of the faults creates local discharge areas in its up-throw side and local recharge areas in its down-throw side. The estimated average linear groundwater velocity in the recharge area is 0.9 mm/day to the eastern direction and 14 mm/day to the northwest. The average linear groundwater discharge velocities range from 0.4 to 0.9 mm/day in the southern part.

  17. Association between early bacterial carriage and otitis media in Aboriginal and non-Aboriginal children in a semi-arid area of Western Australia: a cohort study

    Directory of Open Access Journals (Sweden)

    Sun Wenxing

    2012-12-01

    Full Text Available Abstract Background Streptococcus pneumoniae (Pnc, nontypeable Haemophilus influenzae (NTHi and Moraxella catarrhalis (Mcat are the most important bacterial pathogens associated with otitis media (OM. Previous studies have suggested that early upper respiratory tract (URT bacterial carriage may increase risk of subsequent OM. We investigated associations between early onset of URT bacterial carriage and subsequent diagnosis of OM in Aboriginal and non-Aboriginal children living in the Kalgoorlie-Boulder region located in a semi-arid zone of Western Australia. Methods Aboriginal and non-Aboriginal children who had nasopharyngeal aspirates collected at age 1-  Results Carriage rates of Pnc, NTHi and Mcat at age 1-  Conclusion Early NTHi carriage in Aboriginal children and Mcat in non-Aboriginal children is associated with increased risk of OM independent of environmental factors. In addition to addressing environmental risk factors for carriage such as overcrowding and exposure to environmental tobacco smoke, early administration of pneumococcal-Haemophilus influenzae D protein conjugate vaccine to reduce bacterial carriage in infants, may be beneficial for Aboriginal children; such an approach is currently being evaluated in Australia.

  18. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical report on reference western arid low-level sites

    International Nuclear Information System (INIS)

    The purpose of the work reported here was to develop an order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid low-level waste site. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. These dose estimates are compared to dose estimates for the intruder-agricultural scenario reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by the findings presented in this report. These results indicate that biotic transport has the potential to influence low-level waste site performance. Through biotic transport, radionuclides may be moved to locations where they can enter exposure pathways to man

  19. The effects of a dry sand layer on groundwater recharge in extremely arid areas: field study in the western Hexi Corridor of northwestern China

    Science.gov (United States)

    Sun, Peng; Ma, Jinzhu; Qi, Shi; Zhao, Wei; Zhu, Gaofeng

    2016-04-01

    Evaporation capacity is an important factor that cannot be ignored when judging whether extreme precipitation events will produce groundwater recharge. The evaporation layer's role in groundwater recharge was evaluated using a lysimeter simulation experiment in the desert area of Dunhuang, in the western part of the Hexi Corridor in northwestern China's Gansu Province. The annual precipitation in the study area is extremely low, averaging 38.87 mm during the 60-year study period, and daily pan evaporation amounts to 2,486 mm. Three simulated precipitation regimes (normal, 10 mm; ordinary annual maximum, 21 mm; and extreme, 31 mm) were used in the lysimeter simulation to allow monitoring of water movement and weighing to detect evaporative losses. The differences in soil-water content to a depth of 50 cm in the soil profile significantly affected rainfall infiltration during the initial stages of rainfall events. It was found that the presence of a dry 50-cm-deep sand layer was the key factor for "potential recharge" after the three rainfall events. Daily precipitation events less than 20 mm did not produce groundwater recharge because of the barrier effect created by the dry sand. Infiltration totaled 0.68 mm and penetrated to a depth below 50 cm with 31 mm of rainfall, representing potential recharge equivalent to 1.7 % of the rainfall. This suggests that only extreme precipitation events offer the possibility of recharge of groundwater in this extremely arid area.

  20. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical report on reference western arid low-level sites

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1982-10-01

    The purpose of the work reported here was to develop an order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid low-level waste site. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. These dose estimates are compared to dose estimates for the intruder-agricultural scenario reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by the findings presented in this report. These results indicate that biotic transport has the potential to influence low-level waste site performance. Through biotic transport, radionuclides may be moved to locations where they can enter exposure pathways to man.

  1. Screening of efficient arbuscular mycorrhizal fungi for Azadirachta indica under nursery condition: a step towards afforestation of semi-arid region of western India

    Directory of Open Access Journals (Sweden)

    K. Banerjee

    2013-01-01

    Full Text Available To optimize nursery practices for efficient plant production procedures and to keep up to the ever growing demand of seedlings, identification of the most suitable species of arbuscular mycorrhizal fungi (AMF, specific for a given tree species, is clearly a necessary task. Sixty days old seedlings of Neem (Azadirachta indica A. Juss raised in root trainers were inoculated with six species of AMF and a mixed inoculum (consortia and kept in green house. Performances of the treatments on this tree species were evaluated in terms of growth parameters like plant height shoot collar diameter, biomass and phosphorous uptake capabilities. Significant and varied increase in the growth parameters and phosphorous uptake was observed for most of the AMF species against control. Consortia culture was found to be the best suited AMF treatment for A.indica, while Glomus intraradices and Glomus mosseae were the best performing single species cultures. It is the first time in the state of Gujarat that a wide variety of AMF species, isolated from the typical semi-arid region of western India, were tested for the best growth performance with one of the most important tree species for the concerned region.

  2. Preliminary assessment of aridity conditions in the Iberian Peninsula

    Science.gov (United States)

    Andrade, C.; Corte-Real, J. A.

    2016-06-01

    Aridity is one of the key elements characterizing the climate of a region, having a severe impact on human activities. Aiming at assessing aridity conditions in the Iberian Peninsula, the spatial distribution of the UNEP aridity index is analyzed during the period 1901-2012. Gridded precipitation and potential evapotranspiration datasets are used on a monthly basis. Results show that the southern half of Iberia is particularly vulnerable to water stress and hence to desertification processes. In particular, the UNEP aridity index reveals an increase and northward extension of the semi-arid regime in the Iberian Peninsula between 1901 and 2012. More than 50% of the north and western territory have experienced humid/sub-humid conditions, while the other regions underwent semi-arid settings. Results also reveal that climate was subjected to spatial and temporal variabilities with an overall statistically significant (at a 95% confidence level) trend to aridification in the south-easternmost and central regions. The remaining territory of the Iberian Peninsula does not reveal statistically significant trends.

  3. Absent otoacoustic emissions predict otitis media in young Aboriginal children: A birth cohort study in Aboriginal and non-Aboriginal children in an arid zone of Western Australia

    Directory of Open Access Journals (Sweden)

    Stokes Annette

    2008-08-01

    Full Text Available Abstract Background Otitis media (OM is the most common paediatric illness for which antibiotics are prescribed. In Australian Aboriginal children OM is frequently asymptomatic and starts at a younger age, is more common and more likely to result in hearing loss than in non-Aboriginal children. Absent transient evoked otoacoustic emissions (TEOAEs may predict subsequent risk of OM. Methods 100 Aboriginal and 180 non-Aboriginal children in a semi-arid zone of Western Australia were followed regularly from birth to age 2 years. Tympanometry was conducted at routine field follow-up from age 3 months. Routine clinical examination by an ENT specialist was to be done 3 times and hearing assessment by an audiologist twice. TEOAEs were measured at ages Results At routine ENT specialist clinics, OM was detected in 55% of 184 examinations in Aboriginal children and 26% of 392 examinations in non-Aboriginal children; peak prevalence was 72% at age 5–9 months in Aboriginal children and 40% at 10–14 months in non-Aboriginal children. Moderate-severe hearing loss was present in 32% of 47 Aboriginal children and 7% of 120 non-Aboriginal children aged 12 months or more. TEOAE responses were present in 90% (46/51 of Aboriginal children and 99% (120/121 of non-Aboriginal children aged Overall prevalence of type B tympanograms at field follow-up was 50% (n = 78 in Aboriginal children and 20% (n = 95 in non-Aboriginal children. Conclusion The burden of middle ear disease is high in all children, but particularly in Aboriginal children, one-third of whom suffer from moderate-severe hearing loss. In view of the frequently silent nature of OM, every opportunity must be taken to screen for OM. Measurement of TEOAEs at age 1–2 months to identify children at risk of developing OM should be evaluated in a routine health service setting.

  4. Hydrological and land-use controls of watershed exports of DOM and nutrients in a large arid river basin of Western China

    Science.gov (United States)

    Hu, Y.; Lu, Y.; Edmonds, J. W.; Zheng, C.; Wang, S.

    2014-12-01

    The Heihe River Basin (HRB) is the second largest inland river basin in arid Western China. The Heihe river has been significantly modified to make human settlements possible, particularly involving regulating water flow and extracting groundwater to support irrigated agriculture. It remains unknown how these engineered modifications alter transfers of carbon and nutrients from the watersheds to the river. We sampled surface water and groundwater in the middle reach of the HRB during contrasting hydrology regimes. In addition to DOM and nutrients (nitrate, nitrite, phosphate), a series of parameters (δ18O, δD, cation, and DIC) were analyzed to constrain water sources. Five DOM fluorescence components were identified, including two terrestrial humic-like components (C1 and C2), two protein-like components (C3 and C4), and one component (C5) indicative of resistant compounds persisting in deep groundwater. During the period of high discharge, high fluxes of DOM and nutrients were observed, and DOM was characterized by higher %C1, %C2 and %C5, lower %C3 and %C4, greater values of humification index, and lower values of fluorescence index (FI). This observation suggests that high riverine flow mobilized soil-derived OM and resistant OM into the river but suppressed the contributions of autochthonous, microbial OM. δ13C-DOC values fell in a general range indicative of the dominance of C3 plants but became more enriched in agricultural areas, indicating the influence of corn OM. A positive correlation between nutrient concentrations versus FI values during the period of low discharge suggests that irrigation return flow was an important source for both nutrients and humic DOM in the river. Our data demonstrate that watershed exports of nutrients and DOM were collectively controlled by hydrology and watershed land use, and the influence of land use was more evident during low discharge regimes.

  5. Evaluation of selected soil properties in semi-arid communal rangelands in the Western Bophirima district, South Africa / Abdoulaye Saley Moussa

    OpenAIRE

    Saley Moussa, Abdoulaye

    2007-01-01

    Concerns were raised over the past decades, on the degradation condition of arid and semi-arid rangelands in South Africa, mainly in areas under communal land management. Baseline information on soil quality is essential to monitor changes in land conditions and assess impacts of land uses and management over time. The objectives of this study, initiated within the framework of the Desert Margins Program, were to characterize and establish baseline indicators of soil quality he...

  6. Using U-series Isotopes To Determine Sources Of Pedogenic Carbonates: Comparison Of Natural And Agricultural Soils In The Semi-arid Southern New Mexico And Western Texas

    Science.gov (United States)

    Nyachoti, S. K.; Ma, L.; Borrok, D. M.; Jin, L.; Tweedie, C. E.

    2012-12-01

    Pedogenic carbonates commonly precipitate from infiltrating soil water in arid and semi-arid lands and are observed in soils of southern New Mexico and western Texas. These carbonates could form an impermeable layer in the soil horizons impairing water infiltration, thus affecting crop growth and yield. It is important to determine the source of C and Ca in these carbonates and to understand conditions favoring their formation, kinetics and precipitation rates. In this study, major elements and U-series isotopes in bulk calcic soils, and weak acid leachates and residues were measured from one irrigated alfalfa site in the Hueco basin near El Paso, TX and one natural shrubland site on the USDA Jornada experimental range in southern NM. The combined geochemical and isotopic results allow us to determine the formation ages of the carbonates; investigate the mobility of U, Th, and major elements in these soils; and infer for the effects of irrigation on carbonate formation in agricultural soils. Our results show distinctive U and Th isotope systems in the two soil profiles analyzed. For example, (234U/238U) ratios in the Jornada bulk soils decrease from ~1.01 to 0.96 towards the surface, consistent with a preferential loss of 234U over 238U during chemical weathering. At the Jornada site, (238U/232Th) ratios decrease while (230Th/238U) increase towards the surface, consistent with a general depletion of U and the immobility of Th in the natural soils. By contrast at the Alfalfa site, (234U/238U) ratios of bulk soils increase from ~ 0.97 to 1.02 towards the surface, suggesting an additional source of external uranium, most likely the irrigation water from Rio Grande which has a (234U/238U) ratio of ~ 1.5 near El Paso. The (238U/232Th) and (230Th/238U) ratios also imply leaching of U from shallower soils but precipitation in greater depths at Alfalfa site; suggests that partial dissolution and re-precipitation of younger carbonates occur. Calculated carbonate ages from U

  7. Carbon uptake and change in net primary productivity of oasis-desert ecosystem in arid western China with remote sensing technique%干旱生态系统净初级生产力估算及变化探测

    Institute of Scientific and Technical Information of China (English)

    张杰; 潘晓玲; 高志强

    2006-01-01

    Arid and semi-arid ecosystems exhibit a spatially complex biogeophysical structure.According to arid western special climate-vegetation characters, the fractional cover of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), bare soil and water are unmixed, using the remote sensing spectral mixture analysis. We try the method to unmix the canopy funation structure of arid land cover in order to avoid the differentiation of regional vegetation system and the disturbance of environmental background. We developed a modified production efficiency model NPP-PEM appropriate for the arid area at regional scale based on the concept of radiation use efficiency. This model refer to the GLO-PEM and CASA model was driven with remotely sensed observations, and calculates not just the conversion efficiency of absorbed photosynthetically active radiation but also the carbon fluxes that determine net primary productivity (NPP). We apply and validate the model in the Kaxger and Yarkant river basins in arid western China. The NPP of the study area in 1992 and 1998 was estimated based on the NPP-PEM model. The results show that the improved PEM model, considering the photosynthetical activation of heterogeneous functional vegetation, is in good agreement with field measurements and the existing literature. An accurate agreement (R2= 0.85, P<0.001) between the estimates and the ground-based measurement was obtained. The spatial distribution of mountain-oasis-desert ecosystem shows an obvious heterogeneous carbon uptake. The results are applicable to add ecosystem studies ranging from characterizing carbon cycle, carbon flux over arid areas to monitoring change in mountain-oasis-desert productivity, stress and management.

  8. Boreal spring precipitation variability in the cold arid western Himalaya during the last millennium, regional linkages, and socio-economic implications

    Science.gov (United States)

    Yadava, Akhilesh K.; Bräuning, Achim; Singh, Jayendra; Yadav, Ram R.

    2016-07-01

    Precipitation in the monsoon shadow zone of the western Himalayan region, largely under the influence of mid-latitude westerlies, is the dominant regional socioeconomic driver. Current knowledge of long-term regional precipitation variability is scarce due to spatially and temporally limited weather and high-resolution proxy climate records. We developed the first boreal spring precipitation reconstruction for the western Himalaya covering the last millennium (1030-2011 C.E.). The annually resolved reconstruction is based on a large tree-ring data set of Himalayan cedar (Cedrus deodara) and neoza pine (Pinus gerardiana) from 16 ecologically homogeneous moisture stressed settings in Kinnaur, western Indian Himalaya. The precipitation reconstruction revealed persistent long-term spring droughts from the 12th to early 16th century C.E. and pluvial from the late 16th century C.E. to recent decades. The late 15th and early 16th centuries (1490-1514 C.E.) displayed the driest episode, with precipitation being ∼15% lower than the long-term mean. The early 19th century (1820-1844 C.E.) was the wettest period of the past millennium, with mean precipitation ∼13% above the long-term mean. The reconstructed boreal spring precipitation from the western Himalaya revealed large-scale consistency with hydrological records from westerly dominated regions in Central Asia, indicating synoptic-scale changes in atmospheric circulation during the major part of the Medieval and Little Ice Age periods. Protracted droughts in Central Asia could have caused severe contraction of the regional economy, as indicated by striking coherence of reconstructed drought periods and historic social upheavals and invasions of India from Central and Western Asian invaders. Vulnerability to climatic extremes underpins the need to develop a better understanding of the temporal and spatial variability in regional hydroclimate in order to devise viable water resource management plans.

  9. Larvicidal potential of wild mustard (Cleome viscosa) and gokhru (Tribulus terrestris) against mosquito vectors in the semi-arid region of Western Rajasthan.

    Science.gov (United States)

    Bansal, S K; Singh, Karam V; Sharma, Sapna

    2014-03-01

    effective as compared to the fruit extracts of T. terrestris indicating that active larvicidal principle may be present in the fruits of this plant species. The studywould be of great importance while formulating the control strategy, for vectors of malaria, dengue and lymphatic filariasis, based on alternative plant based insecticides in this semi-arid region. PMID:24665757

  10. 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

  11. 西部干旱区农业野外科学观测试验台站发展现状%Current situation of the development of the agriculture field scientific observation test stations in western arid regions of China

    Institute of Scientific and Technical Information of China (English)

    高峰; 孟宪学; 张雨; 李宁; 王艳娜; 王琛

    2011-01-01

    阐述了野外科学观测试验台站的功能,界定了西部干旱区农业野外科学观测试验台站的内涵,通过对西部干旱区农业野外科学观测试验台站的学科领域分布、野外监(观)测和基础数据积累情况、观测人员结构、基础设施与条件平台、科研立项、研究成果以及人才培养等5方面的调查分析,提出了相关建议.%On the definition of the western arid areas, the paper uses ways of coordinate location and the field survey to select the agricultural field observation scientific test stations in to the western arid areas of China, and expounds the functional orientation, connotation and subject classification of the agricultural field observation scientific test stations in the western arid areas. Through the preliminary investigation analysis of the domanial distribution of the field scientific observations in western arid areas, field observation and the situation of the basic data accumulation, the structure of observers, infrastructure and condition platform, scientific research projects selection, research findings and personnel training, the paper draw a conclusion that the subject classification of the agricultural field observation scientific test stations in the western arid areas mainly are farmland ecological system field observation scientific test stations, up to 44% of all stations. Compared with department field stations and scientific research field stations, the number of scientific research personnel in national field stations is much larger. Personnel with doctor degree and with master degree increased 180% and 60% respectively. The percentage of doctor master and undergraduate changed from 1:1:2 in 2006 to 14; 8; 15 in 2010. The education background of scientific research personnel of the field stations in the western arid areas continued to increase. The scale of experimental observation area and living area of the agricultural field observation scientific test stations

  12. Does predation danger on southward migration curtail parental investment by female western sandpipers?

    NARCIS (Netherlands)

    Jamieson, S.E.; Ydenberg, R.C.; Lank, D.B.

    2014-01-01

    Theory predicts that if extending parental care delays migratory departure, and if later migration is more dangerous, then parental care should be curtailed to make an earlier departure. Adult western sandpipers (Calidris mauri) depart Alaska in July, and the presence of peregrine falcons (Falco per

  13. Dmbt1 does not affect a Western style diet-induced liver damage in mice

    DEFF Research Database (Denmark)

    Reichold, Astrid; Brenner, Sibylle A; Förster-Fromme, Karin;

    2013-01-01

    In the last three decades the prevalence of non-alcoholic fatty liver disease has markedly increased. Results from epidemiologic studies indicate that not only a general overnutrition but rather a diet rich in sugar, fat and cholesterol (= Western style diet) maybe a risk factor for the developme...

  14. Trace Metals in Groundwater and the Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

    International Nuclear Information System (INIS)

    Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Our facilitated approach, shown schematically in Figure 1, relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long-term. Another advantage of the ureolysis approach is that the ammonium ions produced by the reaction can exchange with radionuclides sorbed to subsurface minerals, thereby enhancing the availability of the radionuclides for re-capture in a more stable solid phase (co-precipitation rather than adsorption)

  15. Dmbt1 does not affect a Western style diet-induced liver damage in mice

    OpenAIRE

    Reichold, Astrid; Brenner, Sibylle A.; Förster-Fromme, Karin; BERGHEIM, INA; Mollenhauer, Jan; Stephan C Bischoff

    2013-01-01

    In the last three decades the prevalence of non-alcoholic fatty liver disease has markedly increased. Results from epidemiologic studies indicate that not only a general overnutrition but rather a diet rich in sugar, fat and cholesterol (= Western style diet) maybe a risk factor for the development of non-alcoholic fatty liver disease. Concerning liver diseases, it is known that Deleted in malignant brain tumors 1 is amongst others related to liver injury and repair. In addition Deleted in ma...

  16. The Malagarasi River Does Not Form an Absolute Barrier to Chimpanzee Movement in Western Tanzania

    OpenAIRE

    Piel, Alex K.; Stewart, Fiona A.; Lilian Pintea; Yingying Li; Miguel A Ramirez; Loy, Dorothy E.; Crystal, Patricia A.; Learn, Gerald H.; Knapp, Leslie A.; Paul M. Sharp; Hahn, Beatrice H.

    2013-01-01

    The Malagarasi River has long been thought to be a barrier to chimpanzee movements in western Tanzania. This potential geographic boundary could affect chimpanzee ranging behavior, population connectivity and pathogen transmission, and thus has implications for conservation strategies and government policy. Indeed, based on mitochondrial DNA sequence comparisons it was recently argued that chimpanzees from communities to the north and to the south of the Malagarasi are surprisingly distantly ...

  17. A western perspective on Kautilya's 'Arthasastra': Does it provide a basis for economic science?

    OpenAIRE

    Clement A. Tisdell

    2003-01-01

    In Arthasastra, Kautilya shows a knowledge of basic economics that had no parallels in Western economic thought until the publication of Adam Smith’s Wealth of Nations in 1776. Although the king was at the centre of the body politic in Kautilya’s time, Kautilya makes it clear that the king is bound by an implicit social contract and that the ultimate objective of the king, in economic and other affairs, should be to benefit his subjects. Their happiness or welfare should be the prime objectiv...

  18. Does Western “Aid” Work?——Changing Discourses and Logics

    Institute of Scientific and Technical Information of China (English)

    Yuan Tingting

    2012-01-01

    International aid,always concerned as the Western aid,has been in decades'development after the Second World War.From the Post -colonial time to the era of globalisation,from Washington Consensus to the Post -Washington Consensus,there are various aid discourses,motives and the intervention logics.This paper explores the Western aid through a critical review to the history and the contemporary development of “aid”.It argues,despite these changes,the fundamental logic of aid,the logic of “catching up”,has not been changed.The related economic and political interventions,such as the aid conditionalities,are all working for this logic,and have caused a lot of criticisms.Aid has not been very successful within the changing agendas.While the foreign aid is moving from intervention to cooperation,to make a more effective “aid”,the traditional donors may learn lessons from the South -South relations.

  19. 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

  20. The malagarasi river does not form an absolute barrier to chimpanzee movement in Western Tanzania.

    Directory of Open Access Journals (Sweden)

    Alex K Piel

    Full Text Available The Malagarasi River has long been thought to be a barrier to chimpanzee movements in western Tanzania. This potential geographic boundary could affect chimpanzee ranging behavior, population connectivity and pathogen transmission, and thus has implications for conservation strategies and government policy. Indeed, based on mitochondrial DNA sequence comparisons it was recently argued that chimpanzees from communities to the north and to the south of the Malagarasi are surprisingly distantly related, suggesting that the river prevents gene flow. To investigate this, we conducted a survey along the Malagarasi River. We found a ford comprised of rocks that researchers could cross on foot. On a trail leading to this ford, we collected 13 fresh fecal samples containing chimpanzee DNA, two of which tested positive for SIVcpz. We also found chimpanzee feces within the riverbed. Taken together, this evidence suggests that the Malagarasi River is not an absolute barrier to chimpanzee movements and communities from the areas to the north and south should be considered a single population. These results have important consequences for our understanding of gene flow, disease dynamics and conservation management.

  1. Does the Loss of ARID1A (BAF-250a Expression in Endometrial Clear Cell Carcinomas Have Any Clinicopathologic Significance? A Pilot Assessment

    Directory of Open Access Journals (Sweden)

    Oluwole Fadare, Idris L. Renshaw, Sharon X. Liang

    2012-01-01

    Full Text Available SWI/SNF chromatin-modification complexes use the energy of ATP hydrolysis to remodel nucleosomes and to affect transcription and several cellular processes. Accordingly, their loss of function has been associated with malignant transformation. ARID1A (the expression of whose product, BAF250a, a key complex component, is lost when mutated has recently been identified as a tumor suppressor gene that is mutated in 46-57% of ovarian clear cell carcinoma (CCC. The purposes of this study are to assess the frequency of loss of BAF250a expression in endometrial CCC and whether this loss has any discernable clinicopathologic implications. 34 endometrial carcinomas with a CCC component (including 22 pure CCC, 8 mixed carcinomas with a 10% CCC component, and 4 carcinosarcomas with a CCC epithelial component, were evaluated by immunohistochemistry using a monoclonal antibody directed against the human BAF250a protein. 5 (22.7% of the 22 pure CCC were entirely BAF250a negative, whereas the remainder showed diffuse immunoreactivity. None of 4 carcinosarcomas and only 1 (12.5% of the 8 mixed carcinomas were BAF250a negative. There was no discernable relationship between BAF250a immunoreactivity status and tumor architectural patterns (solid, papillary or tubulocystic areas or cell type (flat, hobnail or polygonal. Of the 22 patients with pure CCC, 14, 2, 3, and 3 were International Federation of Gynecology and Obstetrics stages 1, II, III and IV respectively. Interestingly, all 5 BAF250a negative cases were late stage [stages III or IV] as compared with 1 of 17 BAF250a positive cases (p=0.0002. Thus, 83% (5/6 of all late stage cases were BAF250a [-], as compared with 0 (0% of the 16 early stage (I or II cases (p=.0002. BAF250a negative and positive cases did not show any statistically significant difference regarding patient age and frequency of lymphovascular invasion or myometrial invasion. As may be anticipated from the concentration of late stage cases in

  2. Effect of zero energy cool chamber and post-harvest treatments on shelf-life of fruits under semi-arid environment of Western India. Part 2. Indian gooseberry fruits

    OpenAIRE

    Singh, Sanjay; A. K. Singh; Joshi, H. K.; Bagle, B. G.; More, T. A.

    2010-01-01

    Effect of zero energy cool chamber (ZECC) along with post-harvest treatments including CaCl2, mustard oil and K2SO4 separately on shelf-life and fruit quality attributes of Indian gooseberry or aonla (Emblica officinalis Gaertn) during storage under semi-arid ecosystem of Gujarat was studied. Increase in physiological loss in weight (PLW), spoilage loss, total soluble solids, total sugar and reducing sugars, reduction in titratable acidity and ascorbic acid were observed during storage period...

  3. 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

  4. Effect of zero energy cool chamber and post-harvest treatments on shelf-life of fruits under semi-arid environment of Western India. Part 1. Ber fruits

    OpenAIRE

    Singh, Sanjay; A. K. Singh; Joshi, H. K.; Lata, K.; Bagle, B. G.; More, T. A.

    2010-01-01

    Effect of zero energy cool chamber (ZECC) along with post-harvest treatments (including CaCl2, mustard oil and K2SO4 separately) on shelf-life and fruit quality attributes of ber (Zizyphus mauritiana Lamk.) cv ‘Gola’ during storage under semi-arid ecosystem of Gujarat was studied. Increase in physiological loss in weight (PLW), spoilage loss, total soluble solids, total sugars, reducing sugar and reduction in titratable acidity, and ascorbic acid during storage were observed in all treatments...

  5. Loss of Nlrp3 Does Not Protect Mice from Western Diet-Induced Adipose Tissue Inflammation and Glucose Intolerance.

    Science.gov (United States)

    Ringling, Rebecca E; Gastecki, Michelle L; Woodford, Makenzie L; Lum-Naihe, Kelly J; Grant, Ryan W; Pulakat, Lakshmi; Vieira-Potter, Victoria J; Padilla, Jaume

    2016-01-01

    We tested the hypothesis that loss of Nlrp3 would protect mice from Western diet-induced adipose tissue (AT) inflammation and associated glucose intolerance and cardiovascular complications. Five-week old C57BL6J wild-type (WT) and Nlrp3 knockout (Nlrp3-/-) mice were randomized to either a control diet (10% kcal from fat) or Western diet (45% kcal from fat and 1% cholesterol) for 24 weeks (n = 8/group). Contrary to our hypothesis that obesity-mediated white AT inflammation is Nlrp3-dependent, we found that Western diet-induced expression of AT inflammatory markers (i.e., Cd68, Cd11c, Emr1, Itgam, Lgals, Il18, Mcp1, Tnf, Ccr2, Ccl5 mRNAs, and Mac-2 protein) were not accompanied by increased caspase-1 cleavage, a hallmark feature of NLRP3 inflammasome activation. Furthermore, Nlrp3 null mice were not protected from Western diet-induced white or brown AT inflammation. Although Western diet promoted glucose intolerance in both WT and Nlrp3-/- mice, Nlrp3-/- mice were protected from Western diet-induced aortic stiffening. Additionally, Nlrp3-/- mice exhibited smaller cardiomyocytes and reduced cardiac fibrosis, independent of diet. Collectively, these findings suggest that presence of the Nlrp3 gene is not required for Western diet-induced AT inflammation and/or glucose intolerance; yet Nlrp3 appears to play a role in potentiating arterial stiffening, cardiac hypertrophy and fibrosis. PMID:27583382

  6. How does land use link terrestrial and aquatic carbon in western North America?: Implications from an agricultural case study in central Montana

    Science.gov (United States)

    Ewing, S. A.; Sigler, W. A.

    2014-12-01

    The fate of soil organic matter with expanding human land use is of increasing concern for planetary health and ecological sustainability. In North American grasslands, cultivation has commonly resulted in loss of stored soil organic carbon to dissolved phases in groundwater and surface water, as well as to atmospheric CO2 via decomposition. In addition, cultivation has released nutrients stored in organic matter and facilitated water movement through soils to benefit crops, increasing groundwater recharge rates. This has altered groundwater chemistry both by changing biogeochemistry of the terrestrial-aquatic interface and by increasing addition of nutrients, herbicides, and pesticides to these systems. In this presentation, we consider the effects of food production practices on terrestrial-aquatic carbon linkages in former grassland ecosystems of western North America. Our data from an agricultural area in central Montana begin to reveal how elevated nitrate and pesticide levels in groundwater on an isolated landform reflect transformation over the last century of a temperate grassland ecosystem for wheat and cattle production. Rates and pathways of carbon and nitrogen loss are inferred from the concentration and isotopic character of both water and carbon and nitrogen over three years in soils, shallow groundwater, emergent springs and surface waters. In this semi-arid, non-irrigated context, the fate of soil organic matter is linked with redistribution of pedogenic carbonate as well as other soil and rock derived solutes. We consider implications for future trends in dissolved carbon and nitrogen in surface waters in the region.

  7. 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)

  8. Formation of Pedogenic Carbonates in the Semi-arid Rio Grande Valley: Insights from Carbon, Major elements, and U-series isotopes in Natural and Agricultural Soils of Southern New Mexico and Western Texas

    Science.gov (United States)

    Nyachoti, S. K.; Ma, L.; Jin, L.; Tweedie, C. E.

    2013-12-01

    Accumulation of pedogenic carbonates in arid and semi-arid soils affects soil porosity, water infiltration, and global carbon cycle. We investigate formation rates of these carbonates under different land uses in the semi-arid Rio Grande valley using mineralogy, concentrations of major elements (including C), and U-series isotopes. Our study sites include one alfalfa farm (Alfalfa) at El Paso, TX under frequent irrigation with saline water from the Rio Grande River, and one natural shrub field under natural rainfall conditions at the USDA Jornada Experimental Range (Jornada) in NM. Major minerals observed at Alfalfa and Jornada are calcite, quartz, and feldspars. Calcite/quartz ratios increase upward in the profile at Alfalfa, suggesting formation of carbonates in shallow soils. Consistently, total carbon increases toward the soil surface at Alfalfa, contributed by both soil organic carbon and soil inorganic carbon (pedogenic carbonates). Concentrations of major elements (e.g Ca, Mg, and Sr) also increase toward the surface at Alfalfa, suggesting surface addition. Alternating trends of enrichment and depletion are observed throughout the soil profiles. In contrast, calcite/quartz ratios decrease toward the surface at Jornada, indicative of leaching at shallow soils and redeposition of calcite at depth. This is in agreement with high soil inorganic carbon contents measured at depth. At Jornada however, the Ca, Mg and Sr concentrations decrease toward the surface, showing typical depletion profiles. (234U/238U) activity ratios in bulk soils increase upward at Alfalfa while at Jornada (234U/238U) ratios decrease toward the surface. (234U/238U) ratios at Alfalfa suggest surface addition of U onto shallow soils probably from irrigation water, which is known to have high (234U/238U) ratios. Jornada shows preferential loss of 234U upward. U-series disequilibrium in pedogenic carbonates enables calculation of their formation ages. At Alfalfa, carbonate ages range from 2

  9. GLDAS Land Surface Models based Aridity Indices

    Science.gov (United States)

    Pande, S.; Ghazanfari, S.

    2011-12-01

    Identification of dryland areas is crucial to guide policy aimed at intervening in water stressed areas and addressing its perennial livelihood or food insecurity. Aridity indices based on spatially relative soil moisture conditions such as NCEP aridity index allow cross comparison of dry conditions between sites. NCEP aridity index is based on the ratio of annual precipitation (supply) to annual potential evaporation (demand). Such an index ignores subannual scale competition between evaporation and drainage functions well as rainfall and temperature regimes. This determines partitioning of annual supply of precipitation into two competing (but met) evaporation and runoff demands. We here introduce aridity indices based on these additional considerations by using soil moisture time series for the past 3 decades from three Land Surface Models (LSM) models and compare it with NCEP index. We analyze global monthly soil moisture time series (385 months) at 1 x 1 degree spatial resolution as modeled by three GLDAS LSMs - VIC, MOSAIC and NOAH. The first eigen vector from Empirical Orthogonal Function (EOF) analysis, as it is the most dominant spatial template of global soil moisture conditions, is extracted. Frequency of nonexceedences of this dominant soil moisture mode for a location by other locations is calculated and is used as our proposed aridity index. An area is indexed drier (relative to other areas in the world) if its frequency of nonexceedence is lower. The EOF analysis reveals that their first eigen vector explains approximately 32%, 43% and 47% of variance explained by first 385 eigen vectors for VIC, MOSAIC and NOAH respectively. The temporal coefficients associated with it for all three LSMS show seasonality with a jump in trend around the year 1999 for NOAH and MOSAIC. The VIC aridity index displays a pattern most closely resembling that of NCEP though all LSM based indices isolate dominant dryland areas. However, all three LSMs identify some parts of

  10. 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

    Water resources scarcity plays an important role in socioeconomic aspect of livelihood pattern in dryland areas. Hydrological perspective of aridity is required for social and economic coping Strategies. Identification of dryland areas is crucial to guide policy aimed at intervening in water stressed areas and addressing its perennial livelihood or food insecurity. Yet, prevailing aridity indices are beset with methodological limitations that restrict their use in delineating drylands and, might be insuffient for decision making frameworks. Palmer's Drought Severity index (PDSI) reports relative soil moisture deviations from long term means, which does not allow cross comparisons, while UNEP's aridity index, the ratio of annual evaporative demand to rainfall supply, ignores site specific soil and vegetation characteristics that are needed for appropriate water balance assessment. We propose to refine UNEP's aridity index by accounting for site specific soil and vegetation to partition precipitation into competing demands of evaporation and runoff. We create three aridity indices at a 1 x 1 degree spatial resolution based on 3 decades of soil moisture time series from three GLDAS Land Surface Models (LSM's): VIC, MOSAIC and NOAH. We compare each LSM model aridity map with the UNEP aridity map which was created based on LSM data forcing. Our approach is to extract the first Eigen function from Empirical Orthogonal Function (EOF) analysis that represents the dominant spatial template of soil moisture conditions of the three LSM's. Frequency of non-exceedence of this dominant soil moisture mode for a location by all other locations is used as our proposed aridity index. The EOF analysis reveals that the first Eigen function explains, respectively, 33%, 43% and 47% of the VIC, NOAH and MOSAIC models. The temporal coefficients associated with the first OF (Orthogonal Function) for all three LSMS clearly show seasonality with a discrete jump in trend around the year 1999

  11. 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

  12. At which scales does landscape structure influence the spatial distribution of elephants in the Western Ghats (India) ?

    OpenAIRE

    Gaucherel, C.; Balasubramanian, M.; Karunakaran, P. V.; Ramesh, B.R.; Muthusankar, G.; Hely, C.; Couteron, Pierre

    2010-01-01

    In spatial ecology, detailed covariance analyses are useful for investigating the influences of landscape properties on fauna and/or flora species. Such ecological influences usually operate at multiple scales, involving biological levels from individual to group, population or community and spatial units from field to farms and regions. The aim of this work was to analyze possible multiscale influences of some landscape properties on elephant distribution in the Western Ghats, India, by appl...

  13. 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

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

    OpenAIRE

    Rebekah Downard; Joanna Endter-Wada; Kettenring, Karin M.

    2014-01-01

    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 a...

  15. Western Samoa.

    Science.gov (United States)

    1985-12-01

    This discussion of Western Samoa, which lies 2575 km northeast of Auckland, New Zealand, focuses on the following: geography; the people; history; government; political conditions; the economy; foreign relations; and relations the US. The population of Western Samoa, as of 1985, totals 163,000 with an annual growth rate of 0.9%. The infant mortality rate is 13/1000; life expectancy is 65 years. The main islands are formed ranges of extinct volcanoes. Volcanic activity last occurred in 1911. More than 2000 years age, waves of Polynesians migrated from Southeast Asia to the Samoan Islands. Samoans are the 2nd largest Polynesian group, after the Maoris of New Zealand, and speak a Polynesian dialect. Samoans have tended to retain their traditional ways despite exposure to European influence for more than 150 years. Most Samoans live within the traditional social system based on an extended family group, headed by a chief. Western Samoans are Christian. Education is free but not compulsory. In 1967, 95% of the children of primary school age attended school. From 1947 to 1961, a series of constitutional advances, assisted by visits from UN missions, brought Western Samoa from dependent status to self-government and finally to independence. The 1960 constitution is based on the British pattern of parliamentary democracy, modified to take Samoan customs into account. The present head of state holds his position for life. Future heads of state will be elected by the Legislative Assembly for 5-year terms. The Parliament consists of the Legislative Assembly and the head of state. The Supreme Court is the superior court of record and has full jurisdiction in civil, criminal, and constitutional matters. The "matai" of chief system still dominates the politics of Western Samoa, although several political parties have been formed and seem to be taking root. The "matai" system is a predominantly conservative force but does provide for change. Western Samoa is predominantly

  16. Microbial ecology of arid environments

    OpenAIRE

    夏江瀛; Ha, Kong-ying

    2013-01-01

    Deserts comprise the largest terrestrial biome, making up approximately one third of the Earth’s land mass. They are defined in terms of moisture deficit using the Aridity Index with values 18°C), cold (

  17. Does smoking status affect the likelihood of consulting a doctor about respiratory symptoms? A pilot survey in Western Australia

    Directory of Open Access Journals (Sweden)

    O'Connor Moira

    2009-02-01

    Full Text Available Abstract Background Smokers attribute respiratory symptoms, even when severe, to everyday causes and not as indicative of ill-health warranting medical attention. The aim of this pilot study was to conduct a structured vignette survey of people attending general practice to determine when they would advise a person with respiratory symptoms to consult a medical practitioner. Particular reference was made to smoking status and lung cancer. Methods Participants were recruited from two general practices in Western Australia. Respondents were invited to complete self-administered questionnaires containing nine vignettes chosen at random from a pool of sixty four vignettes, based on six clinical variables. Twenty eight vignettes described cases with at least 5% risk of cancer. For analysis these were dubbed 'cancer vignettes'. Respondents were asked if they would advise a significant other to consult a doctor with their respiratory symptoms. Logistic regression and non-parametric tests were used to analyse the data. Results Three hundred questionnaires were distributed and one hundred and forty completed responses were collected over six weeks. The majority (70.3% of respondents were female aged forty and older. A history of six weeks' of symptoms, weight loss, cough and breathlessness independently increased the odds of recommending a consultation with a medical practitioner by a factor of 11.8, 2.11, 1.40 and 4.77 respectively. A history of smoking independently increased the odds of the person being thought 'likely' or 'very likely' to have cancer by a factor of 2.46. However only 32% of cancer vignettes with a history of cigarette smoking were recognised as presentations of possible cancer. Conclusion Even though a history of cigarette smoking was more likely to lead to the suggestion that a symptomatic person may have cancer we did not confirm that smokers would be more likely to be advised to consult a doctor, even when presenting with common

  18. Does residing in urban or rural areas affect the incidence of polypharmacy among older adults in western China?

    Science.gov (United States)

    Yang, Ming; Lu, Jing; Hao, Qiukui; Luo, Li; Dong, Birong

    2015-01-01

    The aim of this study is to explore the differences among older adults who are rural or urban residents with respects to their socioeconomic position, chronic health conditions and medication use. This cross-sectional study included 887 community-dwelling older adults (≥60 years) from western China. Trained interviewers collected data from all of the study subjects through face-to-face interviews. Polypharmacy was defined as the concomitant use of five or more medications. A total of 717 participants were included in the study analyses. Compared with their urban counterparts, the older adults in rural China were more likely to have more chronic health conditions, and a lower education level, annual income and insurance coverage rate. In addition, the rural inhabitants were less likely to use medications (58.7% vs. 75.7%, ppolypharmacy was significantly lower in rural residents than urban residents (11.5% vs. 17.5%, p=0.021). Urban residence (odds ratios (OR) 1.89, 95% confidence intervals (CI) 1.03-3.48), number of chronic conditions (OR 1.95, 95% CI 1.16-3.30), diabetes (OR 4.14, 95% CI 2.33-7.37), and cardiovascular disease (CVD) (OR 2.09, 95% CI 1.25-3.51) were positively associated with polypharmacy, whereas good self-rated health (OR 0.32, 95% CI 0.16-0.65) was negatively associated with polypharmacy. In conclusion, urban residence is independently associated with polypharmacy in Chinese elders regardless of chronic health conditions and socioeconomic status. PMID:25440757

  19. Close-out report Fitzner-Eberhardt Arid Lands Ecology Reserve remedial action, Hanford, Washington

    International Nuclear Information System (INIS)

    The Fitzner-Eberhardt Arid Lands Ecology (ALE) Reserve consists of 312 km2 (120 mi2) of shrub-steppe land on the western edge of the Hanford Site. It is located south of Highway 240 and east of the point where the Yakima River borders the site. The land was set aside as a natural research area in 1967 by the Atomic Energy Commission. Historically tribal land, the area was homesteaded by pioneers before it was taken by the federal government in 1943 as a security buffer to protect the Hanford Site defense production facilities. One antiaircraft artillery battery (latter converted to a Nike missile site) was located on this land; plutonium production plants or storage facilities were never built there. A more complete account can be found in the Preliminary Assessment Screening (PAS) Report for the Arid Lands Ecology Reserve, Hanford. With the recent change in mission at the Hanford Site from plutonium production to environmental cleanup, much attention has been given to releasing clean tracts of land for other uses. The ALE Reserve is one such tract of land. The existing areas of contamination in the ALE Reserve were considered to be small. In March 1993, the U.S. Department of Energy (DOE), the Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) signed and Agreement in Principle in which they agreed to expedite cleanup of the ALE Reserve. Cleanup activities and a draft close-out report were to be completed by October 1994. Additionally, DOE proposed to mitigate hazards that may pose a physical threat to wildlife or humans

  20. Average Stand Age from Forest Inventory Plots Does Not Describe Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America.

    Science.gov (United States)

    Stevens, Jens T; Safford, Hugh D; North, Malcolm P; Fried, Jeremy S; Gray, Andrew N; Brown, Peter M; Dolanc, Christopher R; Dobrowski, Solomon Z; Falk, Donald A; Farris, Calvin A; Franklin, Jerry F; Fulé, Peter Z; Hagmann, R Keala; Knapp, Eric E; Miller, Jay D; Smith, Douglas F; Swetnam, Thomas W; Taylor, Alan H

    2016-01-01

    Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the "stand age" variable from the US Forest Service Forest Inventory and Analysis (FIA) program reflects the timing of historical high-severity (i.e. stand-replacing) fire in ponderosa pine and mixed-conifer forests. To test this assumption, we re-analyze the dataset used in a previous analysis, and compare information from fire history records with information from co-located FIA plots. We demonstrate that 1) the FIA stand age variable does not reflect the large range of individual tree ages in the FIA plots: older trees comprised more than 10% of pre-stand age basal area in 58% of plots analyzed and more than 30% of pre-stand age basal area in 32% of plots, and 2) recruitment events are not necessarily related to high-severity fire occurrence. Because the FIA stand age variable is estimated from a sample of tree ages within the tree size class containing a plurality of canopy trees in the plot, it does not necessarily include the oldest trees, especially in uneven-aged stands. Thus, the FIA stand age variable does not indicate whether the trees in the predominant size class established in response to severe fire, or established during the absence of fire. FIA stand age was not designed to measure the time since a stand-replacing disturbance. Quantification of historical "mixed-severity" fire regimes must be explicit about the spatial scale of high-severity fire effects, which is not possible using FIA stand age data. PMID:27196621

  1. Average Stand Age from Forest Inventory Plots Does Not Describe Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America.

    Directory of Open Access Journals (Sweden)

    Jens T Stevens

    Full Text Available Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the "stand age" variable from the US Forest Service Forest Inventory and Analysis (FIA program reflects the timing of historical high-severity (i.e. stand-replacing fire in ponderosa pine and mixed-conifer forests. To test this assumption, we re-analyze the dataset used in a previous analysis, and compare information from fire history records with information from co-located FIA plots. We demonstrate that 1 the FIA stand age variable does not reflect the large range of individual tree ages in the FIA plots: older trees comprised more than 10% of pre-stand age basal area in 58% of plots analyzed and more than 30% of pre-stand age basal area in 32% of plots, and 2 recruitment events are not necessarily related to high-severity fire occurrence. Because the FIA stand age variable is estimated from a sample of tree ages within the tree size class containing a plurality of canopy trees in the plot, it does not necessarily include the oldest trees, especially in uneven-aged stands. Thus, the FIA stand age variable does not indicate whether the trees in the predominant size class established in response to severe fire, or established during the absence of fire. FIA stand age was not designed to measure the time since a stand-replacing disturbance. Quantification of historical "mixed-severity" fire regimes must be explicit about the spatial scale of high-severity fire effects, which is not possible using FIA stand age data.

  2. Average Stand Age from Forest Inventory Plots Does Not Describe Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America

    Science.gov (United States)

    Stevens, Jens T.; Safford, Hugh D.; North, Malcolm P.; Fried, Jeremy S.; Gray, Andrew N.; Brown, Peter M.; Dolanc, Christopher R.; Dobrowski, Solomon Z.; Falk, Donald A.; Farris, Calvin A.; Franklin, Jerry F.; Fulé, Peter Z.; Hagmann, R. Keala; Knapp, Eric E.; Miller, Jay D.; Smith, Douglas F.; Swetnam, Thomas W.; Taylor, Alan H.

    2016-01-01

    Quantifying historical fire regimes provides important information for managing contemporary forests. Historical fire frequency and severity can be estimated using several methods; each method has strengths and weaknesses and presents challenges for interpretation and verification. Recent efforts to quantify the timing of historical high-severity fire events in forests of western North America have assumed that the “stand age” variable from the US Forest Service Forest Inventory and Analysis (FIA) program reflects the timing of historical high-severity (i.e. stand-replacing) fire in ponderosa pine and mixed-conifer forests. To test this assumption, we re-analyze the dataset used in a previous analysis, and compare information from fire history records with information from co-located FIA plots. We demonstrate that 1) the FIA stand age variable does not reflect the large range of individual tree ages in the FIA plots: older trees comprised more than 10% of pre-stand age basal area in 58% of plots analyzed and more than 30% of pre-stand age basal area in 32% of plots, and 2) recruitment events are not necessarily related to high-severity fire occurrence. Because the FIA stand age variable is estimated from a sample of tree ages within the tree size class containing a plurality of canopy trees in the plot, it does not necessarily include the oldest trees, especially in uneven-aged stands. Thus, the FIA stand age variable does not indicate whether the trees in the predominant size class established in response to severe fire, or established during the absence of fire. FIA stand age was not designed to measure the time since a stand-replacing disturbance. Quantification of historical “mixed-severity” fire regimes must be explicit about the spatial scale of high-severity fire effects, which is not possible using FIA stand age data. PMID:27196621

  3. Late Holocene subalpine lake sediments record a multi-proxy shift to increased aridity at 3.65 kyr BP, following a millennial-scale neopluvial interval in the Lake Tahoe watershed and western Great Basin, USA

    Science.gov (United States)

    Noble, Paula; Zimmerman, Susan; Ball, Ian; Adams, Kenneth; Maloney, Jillian; Smith, Shane

    2016-04-01

    lake-level rise beginning at some point after 5 kcal yr BP and reaching a highstand of about 1186 m between 3.8 - 4.1 kcal yr BP (Briggs et al., 2005), but new OSL ages on Holocene shorelines are pending. In the Walker, Mono, and Owens lake basins, the neopluvial shorelines represent the highest late Holocene shorelines (Stine, 1990; Adams et al., 2014). Collectively, these studies indicate that the neopluvial and subsequent aridification intervals preserved in Fallen Leaf Lake sediments were at least regional in scale, affecting the watersheds in the northern Sierra Nevada-western Great Basin

  4. 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...

  5. 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

  6. Enclosing the commons: reasons for the adoption and adaptation of enclosures in the arid and semi-arid rangelands of Chepareria, Kenya

    OpenAIRE

    Wairore, John N; Mureithi, Stephen M.; Wasonga, Oliver V; Nyberg, Gert

    2015-01-01

    The adoption and adaptation of enclosures in the arid and semi-arid rangelands of sub-Saharan Africa is driven and sustained by a combination of factors. However, reviews indicate that these factors cannot be generalized, as they tend to be case specific. A study was therefore conducted to explore the history and reasons for enclosure establishment in Chepareria, a formerly degraded communal rangeland in north-western Kenya. While Vi-Agroforestry Organization accounting for 52.5 % was the mai...

  7. 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.

  8. Soil carbon in the arid and semi-arid tropics

    International Nuclear Information System (INIS)

    Soils in the arid and semi-arid tropics are often poor in soil organic matter (SOM) contents. On the other hand, calcretes and soils with calcic or petrocalcic horizons have a world-wide distribution and are regarded as important carbon reservoirs. For this reason, knowledge on their formation processes and the carbon source-sink relationship is necessary. An evaluation is made of the major models of calcrete formation using stable isotope techniques, especially on Tunisian soils. Normally, calcretes do not act as carbon sinks unless at least part of the calcium originates from weathering. However, in some cases they can change to carbon sources under anthropogenically altered environmental conditions when acids are precipitated. Desert losses are quite rich in carbonates and can form fertile soils, but good management practices and conservation efforts are required. These soils are usually poor in SOM contents and their carbon source-sink relationship depends on the way in which the soil is managed. Vertisols play an important role in soils of the semi-arid tropics. Despite their dark colour, they generally contain little organic carbon. Using stable isotope and radiocarbon methods it has been shown that carbon fixation takes place even over a few decades. Research experiments carried out on Vertisols in India have shown that the SOM decomposition rates can be influenced by the soil management practices. (author). 3 figs

  9. The case of arid and semi-arid zones; Le cas des zones arides et semi-arides

    Energy Technology Data Exchange (ETDEWEB)

    Agoumi, A. [Ecole Hassania, Casablanca (Morocco); Stour, L. [Hassan Univ., Mohammedia (Morocco). Faculty of Sciences

    2009-07-15

    This article addressed issues regarding the conservation and sustainable use of biomass resources in arid and semi-arid zone ecosystems. Conservation strategies for climatic zones threatened by increased pressure from intensified land use, drought, and land degradation were discussed along with sustainable land use management practices. The strategies range from strict regulations for environmental protection to various forms of conservation easements, such as carbon credits. The article also supported the initiative to reduce emissions caused by deforestation and degradation (REDD). The REDD initiative proposes that future global climate agreements should first aim to reduce the total forested area lost in the tropics and then to eventually cease global deforestation. It was concluded that sustainable forestry at a global level is needed in order to achieve mitigation targets and to avoid the risk that forests may becomes a net carbon source rather than carbon sinks. 3 figs.

  10. How does forest thinning affect short- and long-term water partitioning in the semi-arid Santa Fe Municipal Watershed, and how do these changes compare to unmediated forest responses to climate change?

    Science.gov (United States)

    Dugger, A. L.; Tague, C.; Allen, C. D.; Ringler, T.

    2011-12-01

    In water-limited environments, water and vegetation systems are intrinsically linked. Vegetation exerts direct controls on water partitioning through transpiration and indirect controls on partitioning through radiation and precipitation interception, rooting effects on soil permeability, and litter effects on water capture and storage, among others. In semi-arid forest systems of the Southwest U.S. in particular, vegetation controls on water partitioning are often the most dominant after climate, so changes in vegetation structure, species type, and biomass can lead to large shifts in downstream water availability. We use a coupled ecologic-hydrologic, process-based model (RHESSys) to investigate how human- and nature-induced changes in vegetation biomass, structure, and spatial distribution affect the partitioning of water into evaporation (E), transpiration (T), groundwater recharge (GW), and streamflow (Q) in the Santa Fe Municipal Watershed in Northern New Mexico. Previous work at this site has shown that RHESSys can successfully capture observed seasonal streamflow patterns and inter-annual biomass dynamics (growth/mortality) in response to climate. In this study, we use sensitivity analysis of model vegetation parameterization to estimate the relative magnitude of responses in E, T, GW, and Q due to a range of different vegetation manipulation scenarios, including uniform changes in biomass, varying spatial patterns of vegetation thinning, increasing canopy cover gaps through thinning, and changes in litter and coarse woody debris. The dynamic vegetation model allows us to not only evaluate instantaneous changes in partitioning associated with these manipulations, but also how partitioning evolves over time. Finally, we compare model estimates of effects on water partitioning from forest treatment to effects from unmediated "natural" vegetation responses to climate warming.

  11. Protocol for VOC-Arid ID remediation performance characterization

    International Nuclear Information System (INIS)

    The Volatile Organic Compound-Arid Integrated Demonstration (VOC-Arid ID) is a technology development program sponsored by the US Department of Energy's Office of Technology Development that is targeted to acquire, develop, demonstrate, and deploy new technologies for the remediation of VOC contaminants in the soils and groundwaters of arid DOE sites. Technologies cannot be adequately evaluated unless sufficient site characterization and technology performance data have been collection and analyzed. The responsibility for identifying these data needs has been placed largely on the Principal Investigators (PIs) developing the remediation technology, who usually are not experts in site characterization or in identification of appropriate sampling, analysis, and monitoring techniques to support the field testing. This document provides a protocol for planning the collection of data before, during, and after a test of a new technology. This generic protocol provides the PIs and project managers with a set of steps to follow. The protocol is based on a data collection planning process called the Data Quality Objectives (DQO) process, which was originally developed by the US Environmental Protection Agency and has been expanded by DOE to support site cleanup decisions. The DQO process focuses on the quality and quantity of data required to make decision. Stakeholders to the decisions must negotiate such key inputs to the process as the decision rules that will be used and the acceptable probabilities of making decision errors

  12. Arid-zone groundwater recharge and palaeorecharge: insights from the radioisotope chlorine-36

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, G.; Wischusen, J. [Australian Geological Survey Organization (AGSO), Canberra, ACT (Australia). Geohazards, Land and Water Resources; Cresswell, R.; Fifield, K. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1998-11-01

    AGSO`s collaborative `Western water` study of groundwater resources in Aboriginal lands in the southwest Northern Territory arid zone, has applied the radioisotope {sup 36}CI and {sup 14}C to investigate the sustainability of community water supplies drawn from shallow aquifers in the Papunya-Kintore-Yuendumu area. The {sup 36}CI results have important implications for groundwater management throughout the arid zone, because substantial recharge occurs only during favourable, wet, interglacial climatic regimes. this has important implications for groundwater management in this area and elsewhere in central Australia, where most of the community water supplies depend on `old` stored groundwater 5 figs.

  13. Arid-zone groundwater recharge and palaeorecharge: insights from the radioisotope chlorine-36

    International Nuclear Information System (INIS)

    AGSO's collaborative 'Western water' study of groundwater resources in Aboriginal lands in the southwest Northern Territory arid zone, has applied the radioisotope 36CI and 14C to investigate the sustainability of community water supplies drawn from shallow aquifers in the Papunya-Kintore-Yuendumu area. The 36CI results have important implications for groundwater management throughout the arid zone, because substantial recharge occurs only during favourable, wet, interglacial climatic regimes. this has important implications for groundwater management in this area and elsewhere in central Australia, where most of the community water supplies depend on 'old' stored groundwater

  14. 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...

  15. Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya

    Directory of Open Access Journals (Sweden)

    Rusk Andria

    2012-08-01

    Full Text Available Abstract Background Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. Methods To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Results Most of the medicine retailers surveyed (65% were able to identify artemether-lumefantrine (AL as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Conclusion Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could

  16. 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.

  17. Precipitation and nitrogen interactions in arid ecosystems

    Science.gov (United States)

    Arid and semi-arid ecosystems are among the most impoverished terrestrial systems in terms of water and nitrogen (N) availability. Productivity (NPP) is generally low, soil N pools are small and N loss through percolation is assumed to be negligible. Increased water availability can stimulate both N...

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

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Lenhard, R.J.; Bjornstad, B.N.; Evans, J.C.; Roberson, K.R.; Spane, F.A.; Amonette, J.E.; Rockhold, M.L.

    1991-10-01

    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 (CCl{sub 4}) contamination located near the center of the Hanford Site. The movement of CCl{sub 4} 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.

  19. 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

  20. Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America

    Science.gov (United States)

    Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex ch...

  1. 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.

  2. Intermediate depth burial of classified transuranic wastes in arid alluvium

    International Nuclear Information System (INIS)

    Intermediate depth disposal operations were conducted by the US Department of Energy (DOE) at the DOE's Nevada Test Site (NTS) from 1984 through 1989. These operations emplaced high-specific activity low-level wastes (LLW) and limited quantities of classified transuranic (TRU) wastes in 37 m (120-ft) deep, Greater Confinement Disposal (GCD) boreholes. The GCD boreholes are 3 m (10 ft) in diameter and founded in a thick sequence of arid alluvium. The bottom 15 m (50 ft) of each borehole was used for waste emplacement and the upper 21 m (70 ft) was backfilled with native alluvium. The bottom of each GCD borehole is almost 200 m (650 ft) above the water table. The GCD boreholes are located in one of the most arid portions of the US, with an average precipitation of 13 cm (5 inches) per year. The limited precipitation, coupled with generally warm temperatures and low humidities results in a hydrologic system dominated by evapotranspiration. The US Environmental Protection Agency's (EPA's) 40 CFR 191 defines the requirements for protection of human health from disposed TRU wastes. This EPA standard sets a number of requirements, including probabilistic limits on the cumulative releases of radionuclides to the accessible environment for 10,000 years. The DOE Nevada Operations Office (DOE/NV) has contracted with Sandia National Laboratories (Sandia) to conduct a performance assessment (PA) to determine if the TRU wastes emplaced in the GCD boreholes complies with the EPA's 40 CFR 191 requirements. This paper describes DOE's actions undertaken to evaluate whether the TRU wastes in the GCD boreholes will, or will not, endanger human health. Based on preliminary modeling, the TRU wastes in the GCD boreholes meet the EPA's requirements, and are, therefore, protective of human health

  3. Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV)

    Energy Technology Data Exchange (ETDEWEB)

    Attalah, Said; Waller, Peter M.; Khawam, George; Ryan, Randy D.; Huesemann, Michael H.

    2015-06-03

    The original Algae Raceway Integrated Design (ARID) raceway was an effective method to increase algae culture temperature in open raceways. However, the energy input was high and flow mixing was poor. Thus, the High Velocity Algae Raceway Integrated Design (ARID-HV) raceway was developed to reduce energy input requirements and improve flow mixing in a serpentine flow path. A prototype ARID-HV system was installed in Tucson, Arizona. Based on algae growth simulation and hydraulic analysis, an optimal ARID-HV raceway was designed, and the electrical energy input requirement (kWh ha-1 d-1) was calculated. An algae growth model was used to compare the productivity of ARIDHV and conventional raceways. The model uses a pond surface energy balance to calculate water temperature as a function of environmental parameters. Algae growth and biomass loss are calculated based on rate constants during day and night, respectively. A 10 year simulation of DOE strain 1412 (Chlorella sorokiniana) showed that the ARID-HV raceway had significantly higher production than a conventional raceway for all months of the year in Tucson, Arizona. It should be noted that this difference is species and climate specific and is not observed in other climates and with other algae species. The algae growth model results and electrical energy input evaluation were used to compare the energy productivity (algae production rate/energy input) of the ARID-HV and conventional raceways for Chlorella sorokiniana in Tucson, Arizona. The energy productivity of the ARID-HV raceway was significantly greater than the energy productivity of a conventional raceway for all months of the year.

  4. Desertification of arid Rangelands in Morocco

    OpenAIRE

    Mahyou, Hamid; Tychon, Bernard; Paul, Roger; Balaghi, Riad; Mimouni, Jamal

    2011-01-01

    Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands. These areas represent livelihoods for thousands of people and protect the country from desertification. Despite the importance of the rangelands and the threat of desertification, it is surprising that up to date there is no comprehensive assessment of their condition ...

  5. Rainfall-runoff modeling in arid areas

    OpenAIRE

    Abushandi, Eyad

    2011-01-01

    The Wadi Dhuliel catchment/ North east Jordan, as any other arid area has distinctive hydrological features with limited water resources. The hydrological regime is characterized by high variability of temporal and spatial rainfall distributions, flash floods, absence of base flow, and high rates of evapotranspiration. The aim of this Ph.D. thesis was to apply lumped and distributed models to simulate stream flow in the Wadi Dhuliel arid catchment. Intensive research was done to estimate the ...

  6. 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

  7. The relationship between anthropogenic dust and population over global semi-arid regions

    Science.gov (United States)

    Guan, Xiaodan; Huang, Jianping; Zhang, Yanting; Xie, Yongkun; Liu, Jingjing

    2016-04-01

    Although anthropogenic dust has received more attention from the climate research community, its dominant role in the production process is still not identified. In this study, we analysed the relationship between anthropogenic dust and population density/change over global semi-arid regions and found that semi-arid regions are major source regions in producing anthropogenic dust. The results showed that the relationship between anthropogenic dust and population is more obvious in cropland than in other land cover types (crop mosaics, grassland, and urbanized regions) and that the production of anthropogenic dust increases as the population density grows to more than 90 persons km-2. Four selected semi-arid regions, namely East China, India, North America, and North Africa, were used to explore the relationship between anthropogenic dust production and regional population. The most significant relationship between anthropogenic dust and population occurred in an Indian semi-arid region that had a greater portion of cropland, and the high peak of anthropogenic dust probability appeared with 220 persons km-2 of population density and 60 persons km-2 of population change. These results suggest that the influence of population on production of anthropogenic dust in semi-arid regions is obvious in cropland regions. However, the impact does not always have a positive contribution to the production of anthropogenic dust, and overly excessive population will suppress the increase of anthropogenic dust. Moreover, radiative and climate effects of increasing anthropogenic dust need more investigation.

  8. Westerns fra hele verden

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2014-01-01

    Om den amerikanske western, spaghettiwesterns, kommunistiske westerns og danske westerns - i forbindelse med Kristian Levrings The Salvation (2014).......Om den amerikanske western, spaghettiwesterns, kommunistiske westerns og danske westerns - i forbindelse med Kristian Levrings The Salvation (2014)....

  9. 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

  10. Global and continental changes of arid areas using the FAO Aridity Index over the periods 1951-1980 and 1981-2010

    Science.gov (United States)

    Spinoni, Jonathan; Micale, Fabio; Carrao, Hugo; Naumann, Gustavo; Barbosa, Paulo; Vogt, Jürgen

    2013-04-01

    An increase in arid areas and progressing land degradation are two of the main consequences of global climate change. In the 2nd edition of the World Atlas of Desertification (WAD), published by the United Nation Environment Program (UNEP) in 1997, a global aridity map was presented. This map was based on the Food and Agriculture Organization (FAO) Aridity Index (AI) that takes into account the annual ratio between precipitation (RR) and Potential Evapo-Transpiration (PET). According to the long-term mean value of this ratio, climate is therefore classified in hyper-arid (0.65); a special case are cold climates, which occur if the mean annual PET is below 400 mm. In the framework of the 3rd edition of the WAD, we computed new global aridity maps to improve and update the old version that was based on a single dataset (CRU dataset, Climate Research Unit of University of East Anglia) related to the 1951-80 period only. We computed the AI on two different time intervals (1951-80 and 1981-2010) in order to account for shifts in classes between the two periods and we used two different datasets: PET from CRU (version 3.2), and precipitation from the global 0.5˚x0.5˚ gridded monthly precipitation of the Global Precipitation Climatology Center (GPCC) of the Deutscher Wetterdienst (DWD). We used the GPCC Full Data Reanalysis Version 6.0, which showed a high reliability during many quality checks and is based on more stations than the CRU's precipitation counterpart. The results show that the "arid areas" (i.e. AI Spain, the Southern Sahara and North-Eastern Kalahari deserts, Rajasthan and Madhya Pradesh (India), Mongolia, the Yang-Tze Basin (China), and the North-Eastern and South-Western Australian coasts. On the other hand, Central U.S., Paraguay and Northern Argentina, Scandinavia, Northern Australia, and Western China moved to a wetter climate in the last period. Due to the low data availability, we assumed that no changes took place in Antarctica, which is meant to

  11. Regional difference of aridity/humidity conditions changeover China during the last thirty years

    Institute of Scientific and Technical Information of China (English)

    YIN Yunhe; WU Shaohong; ZHENG Du; YANG Qingye

    2005-01-01

    The meteorological data of 616 stations in China were used to calculate the potential evapotranspiration and aridity/humidity index by applying the modified FAO-Penman-Monteith model. Regional difference of trends in precipitation, potential evapotranspiration and aridity/humidity index over China and their interdecadal variations were analyzed from 1971 to 2000. The results show that all the four climatic factors trends have obvious regional difference and interdecadal variations. Annual precipitation during the 30-year period shows an increasing trend over most regions of China, with decreasing trends in potential evapotranspiration and aridity/humidity index. Most regions in China become more humid, especially significant in northern Xinjiang, eastern Tibet, western Sichuan, and northern Yunnan. The average value over China would mask the regional difference of climate change because of the complex environmental condition in China. Therefore regional difference should be analyzed to further understand climate change and its impacts. Both water supply and demand need to be considered when attempting to study regional aridity/humidity conditions.

  12. Development of a three-dimensional groundwater flow model for Western Melton Valley: Application of P-FEM on a DOE waste site

    International Nuclear Information System (INIS)

    Modeling the movement of hazardous waste in groundwater was identified by the US Department of Energy (DOE) as one of the grand challenges in scientific computation. In recognition of this need, DOE has provided support for a group of scientists from several national laboratories and universities to conduct research and development in groundwater flow and contaminant transport modeling. This group is part of a larger consortium of researchers, collectively referred to as the Partnership in Computational Science (PICS), that has been charged with the task of applying high-performance computational tools and techniques to grand challenge areas identified by DOE. One of the goals of the PICS Groundwater Group is to develop a new three-dimensional groundwater flow and transport code that is optimized for massively parallel computers. An existing groundwater flow code, 3DFEMWATER, was parallelized in order to serve as a benchmark for these new models. The application of P-FEM, the parallelized version of 3DFEMWATER, to a real field site is the subject of this report

  13. 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.

  14. 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.

  15. Untangling a species complex of arid zone grasses (Triodia) reveals patterns congruent with co-occurring animals.

    Science.gov (United States)

    Anderson, Benjamin M; Barrett, Matthew D; Krauss, Siegfried L; Thiele, Kevin

    2016-08-01

    The vast Australian arid zone formed over the last 15million years, and gradual aridification as well as more extreme Pliocene and Pleistocene climate shifts have impacted the evolution of its biota. Understanding the evolutionary history of groups of organisms or regional biotas such as the Australian arid biota requires clear delimitation of the units of biodiversity (taxa). Here we integrate evidence from nuclear (ETS and ITS) and chloroplast (rps16-trnK spacer) regions and morphology to clarify taxonomic boundaries in a species complex of Australian hummock grasses (Triodia) to better understand the evolution of Australian arid zone plants and to evaluate congruence in distribution patterns with co-occurring organisms. We find evidence for multiple new taxa in the T. basedowii species complex, but also incongruence between data sets and indications of hybridization that complicate delimitation. We find that the T. basedowii complex has high lineage diversity and endemism in the biologically important Pilbara region of Western Australia, consistent with the region acting as a refugium. Taxa show strong geographic structure in the Pilbara, congruent with recent work on co-occurring animals and suggesting common evolutionary drivers across the biota. Our findings confirm recognition of the Pilbara as an important centre of biodiversity in the Australian arid zone, and provide a basis for future taxonomic revision of the T. basedowii complex and more detailed study of its evolutionary history and that of arid Australia. PMID:27179699

  16. 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

  17. 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.

  18. Who Engages in Water Scarcity Conflicts? A Field Experiment with Irrigators in Semi-arid Africa

    OpenAIRE

    D'Exelle, Ben; Lecoutere, Els; Van Campenhout, Bjorn

    2010-01-01

    Does water scarcity induce conflict? And who would engage in a water scarcity conflict? In this paper we look for evidence of the relation between water scarcity and conflictive behavior. With a framed field experiment conducted with smallholder irrigators from semi-arid Tanzania that replicates appropriation from an occasionally scarce common water flow we assess what type of water users is more inclined to react in conflictive way to scarcity. On average, water scarcity induces selfish appr...

  19. 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

  20. 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

  1. Contribution of Afforestation Practices to Changing Hydrology in Arid and Semi-arid Regions

    Science.gov (United States)

    Xie, X.; Meng, S.; Li, J.

    2014-12-01

    Arid and semi-arid regions are generally susceptible to land degeneration due to limited precipitation and high potential evapotranspiration (ET). Afforestation has been assumed to be a feasible strategy to conserve water and to improve ecological environment. For example, the Northern China, as a typical arid and semi-arid region has experienced large-scale and long-term afforestation practices since the early 1980s. The land cover has been altered to some degree as tree planting with increasing greenness. However, the effectiveness of afforestation might not be as expected due to the interference of climate change. In this study, we attempted to quantify the contribution of afforestation practices to the hydrological system in the Northern China. A macro-scale hydrological model, i.e., the Variable Infiltration Capacity (VIC), was employed to simulate ET, soil moisture and runoff for the period 1959 - 2009. Fractional simulation scenarios were designed regarding different conditions of land cover and climate changes. The results indicate that the land cover has minor impact on the variability of hydrological variables at regional scale, comparing with the climate change. Particularly, the decreasing precipitation plays a dominant role in shaping the trends of ET, soil moisture and runoff. The findings have significant implications for the implementation of the afforestation practices and for the management of water resources in arid and semi-arid regions.

  2. 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.

  3. 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

  4. Were Semi-Arid Areas Wetter or Drier during the Pliocene?

    Science.gov (United States)

    Feakins, S. J.; Liddy, H.; Tierney, J. E.

    2014-12-01

    Drying is projected for many semi-arid areas under global warming scenarios. The Pliocene provides a natural analog for global warmth, allowing us to test the terrestrial response to past warming. Today North East Africa (O to 12 N, 38 to 50 E) includes C3 shrubs in arid areas, C4 grasslands in semi-arid areas and C3 trees in the moister uplands. Here we take a biomarker approach to reconstructing terrestrial vegetation and hydrological changes in NE Africa during the Pliocene and develop complementary records of sea surface temperature (SST) changes in the Western Indian Ocean. We find the plant leaf wax carbon isotopic negative anomaly to be ambiguous. Woody cover interpretations suggest afforestation with C3 trees. But an alternative explanation, an increase of dry C3 shrublands, appears more likely based on drying evidence from hydrogen isotopes and pollen for an expansion of shrub taxa. Either change implies a contraction of the Miocene C4 grasslands. To explore the mechanisms for drying we look to the Western Indian Ocean and find biomarker trends show a coincident cooling (in contrast to Mg/Ca), providing a mechanism to reduce moisture supply to the continent. We are adding to the resolution and coverage of the d13C, dD, pollen and TEX86 records in order to assess whether this Pliocene scenario is robust. Specifically we are testing the hypothesis that a cooling trend in the Western Indian Ocean is coincident with a drying and C3 shrubland expansion. Our work to resolve these quite different scenarios (afforestation or aridification on land) is key, since model simulations have offered up both wetter and drier regional responses to Pliocene global warmth and questions about the direction of SST changes (warming or cooling Indian Ocean across the Pliocene) forms part of the larger present debate about the fidelity of Pliocene SST proxies.

  5. Production of hybrids between western gray wolves and western coyotes.

    Directory of Open Access Journals (Sweden)

    L David Mech

    Full Text Available Using artificial insemination we attempted to produce hybrids between captive, male, western, gray wolves (Canis lupus and female, western coyotes (Canis latrans to determine whether their gametes would be compatible and the coyotes could produce and nurture offspring. The results contribute new information to an ongoing controversy over whether the eastern wolf (Canis lycaon is a valid unique species that could be subject to the U. S. Endangered Species Act. Attempts with transcervically deposited wolf semen into nine coyotes over two breeding seasons yielded three coyote pregnancies. One coyote ate her pups, another produced a resorbed fetus and a dead fetus by C-section, and the third produced seven hybrids, six of which survived. These results show that, although it might be unlikely for male western wolves to successfully produce offspring with female western coyotes under natural conditions, western-gray-wolf sperm are compatible with western-coyote ova and that at least one coyote could produce and nurture hybrid offspring. This finding in turn demonstrates that gamete incompatibility would not have prevented western, gray wolves from inseminating western coyotes and thus producing hybrids with coyote mtDNA, a claim that counters the view that the eastern wolf is a separate species. However, some of the difficulties experienced by the other inseminated coyotes tend to temper that finding and suggest that more experimentation is needed, including determining the behavioral and physical compatibility of western gray wolves copulating with western coyotes. Thus although our study adds new information to the controversy, it does not settle it. Further study is needed to determine whether the putative Canis lycaon is indeed a unique species.

  6. Production of hybrids between western gray wolves and western coyotes

    Science.gov (United States)

    Mech, L. David; Christensen, Bruce W.; Asa, Cheryl S.; Callahan, Magaret; Young, Julie K.

    2014-01-01

    Using artificial insemination we attempted to produce hybrids between captive, male, western, gray wolves (Canis lupus) and female, western coyotes (Canis latrans) to determine whether their gametes would be compatible and the coyotes could produce and nurture offspring. The results contribute new information to an ongoing controversy over whether the eastern wolf (Canis lycaon) is a valid unique species that could be subject to the U. S. Endangered Species Act. Attempts with transcervically deposited wolf semen into nine coyotes over two breeding seasons yielded three coyote pregnancies. One coyote ate her pups, another produced a resorbed fetus and a dead fetus by C-section, and the third produced seven hybrids, six of which survived. These results show that, although it might be unlikely for male western wolves to successfully produce offspring with female western coyotes under natural conditions, western-gray-wolf sperm are compatible with western-coyote ova and that at least one coyote could produce and nurture hybrid offspring. This finding in turn demonstrates that gamete incompatibility would not have prevented western, gray wolves from inseminating western coyotes and thus producing hybrids with coyote mtDNA, a claim that counters the view that the eastern wolf is a separate species. However, some of the difficulties experienced by the other inseminated coyotes tend to temper that finding and suggest that more experimentation is needed, including determining the behavioral and physical compatibility of western gray wolves copulating with western coyotes. Thus although our study adds new information to the controversy, it does not settle it. Further study is needed to determine whether the putative Canis lycaon is indeed a unique species.

  7. Rainfall Characterization In An Arid Area

    OpenAIRE

    Bazaraa, A. S.; Ahmed, Shamim

    1991-01-01

    The objective of this work is to characterize the rainfall in Doha which lies in an arid region. The rainfall data included daily rainfall depth since 1962 and the hyetographs of the individual storms since 1976. The rainfall is characterized by high variability and severe thunderstorms which are of limited geographical extent. Four probability distributions were used to fit the maximum rainfall in 24 hours and the annual rainfall depth. The extreme value distribution was found to have the be...

  8. Comment on: “Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?” by Mary L. Leech, Earth and Planetary Science Letters 276 (2008) 314-322

    Science.gov (United States)

    Searle, M. P.; Phillips, R. J.

    2009-09-01

    Leech [Leech, M.L., 2008, Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya? Earth Planet. Sci. Lett., 276, 314-322.] proposed that (1) Himalayan granites are significantly more abundant east of the Karakoram fault termination (around Mount Kailas, in SW Tibet) than west of it in the Zanskar-Kumaon region, that (2) the fault may have created a barrier to southward flow of mid-crustal channel flow, and that (3) the fault acted as a vertical conduit for these melts. These inferences are based upon new U-Pb SHRIMP data from the Leo Pargil dome, NW India, and the analysis of published U-Pb ages from additional Himalayan domes. Here we point out the flaws in all these hypotheses and suggest a much closer comparison of granites along the Karakoram shear zone to the widespread Miocene crustal melt granites of the Baltoro Karakoram range in North Pakistan. Field relationships combined with U-(Th)-Pb dating of granites and metamorphic rocks clearly shows that the leucogranites exhumed along the Karakoram fault are related to regional metamorphic and melting events along the Baltoro Karakoram range of the Asian plate and not to Indian plate Himalayan leucogranites at all. We discuss individually the points raised.

  9. Cereals for the semi-arid tropics

    International Nuclear Information System (INIS)

    The region of semi-arid tropics is the most famine prone area of the world. This region with nearly one billion people extends across some 20 million square kilometres. Major domesticated cereals adapted to semi-arid regions are sorghum (Sorghum bicolor (L.) Moench), foxtail millet (Setaria italica (L.) P. Beauv.) and pearl millet (Pennisetum glaucum (L.) R. Br.). Several minor cereals are grown as speciality crops, or harvested in the wild in times of severe drought and scarcity. Important in the African Sahel are the fonios Digitaria iburua Stapf, D. exilis (Kapist) Stapf and Brachiaria deflexa (Schumach). C.E. Hubbard. These species are aggressive colonizers and are commonly encouraged as weeds in cultivated fields. Sown genotypes differ from their close wild relatives primarily in the lack of efficient natural seed dispersal. The fonios lend themselves to rapid domestication. Several wild cereals extend well beyond the limits of agriculture into the Sahara. Commonly harvested are the perennial Stipagrostis pungens and Panicum turgidum, and the annual Cenchrus biflorus (kram-kram). Kram-kram yields well under extreme heat and drought stress, and holds promise as a domesticated cereal. Sauwi millet (Panicum sonorum) is promising cereal in arid northwestern Mexico. (author). 31 refs

  10. Ecotoxicology for risk assessment in arid zones: some key issues.

    Science.gov (United States)

    Everts, J W

    1997-01-01

    In the hot arid zones of the world, ecotoxicological research is in statu nascendi. In these zones, the major sources of contamination by toxicants are: (1) plant protection and vector control in wet zones; (2) large-scale crop protection campaigns in dry and ephemeral wet zones; (3) refuse and obsolete pesticides in dry zones; and (4) mining. Economic development in many of these zones requires an adequate knowledge of certain basic principles, i.e., where extrapolating existing knowledge does not apply. The vulnerability of ecosystems to contaminants is closely related to water flow. In dry areas, species are susceptible to factors that interfere with the ecophysiological properties regulating water loss. Most hot arid areas are found at low latitudes where temperatures show striking extremes both in time and space. Living organisms are physiologically resistant and/or show adaptive behavior to these temperature extremes. Very little is known about the effects of toxicants on these key resistant and adaptive functions, although by extrapolation a few assumptions can be made. The effects of hyperthermia, for instance, can be aggravated by GSH depleting substances, and the temporary disabling effects characteristic of many pesticides may prove fatal under these circumstances. Most wet areas show a spatial concentration of both human activity and wildlife. In mesic zones, the contamination of water represents a health risk to both humans and other living organisms. The vast majority of aquatic communities are those inhabiting temporary pools and streams. Their populations are characterized by short reproductive cycles and/or long dormant stages. Toxicants affecting growth in these areas have been shown to have a deleterious effect. In a synthesis of existing knowledge the most prominent gaps are identified and priorities for further research are made. PMID:9002429

  11. HIC1 interacts with a specific subunit of SWI/SNF complexes, ARID1A/BAF250A

    International Nuclear Information System (INIS)

    HIC1, a tumor suppressor gene epigenetically silenced in many human cancers encodes a transcriptional repressor involved in regulatory loops modulating p53-dependent and E2F1-dependent cell survival and stress responses. HIC1 is also implicated in growth control since it recruits BRG1, one of the two alternative ATPases (BRM or BRG1) of SWI/SNF chromatin-remodeling complexes to repress transcription of E2F1 in quiescent fibroblasts. Here, through yeast two-hybrid screening, we identify ARID1A/BAF250A, as a new HIC1 partner. ARID1A/BAF250A is one of the two mutually exclusive ARID1-containing subunits of SWI/SNF complexes which define subsets of complexes endowed with anti-proliferative properties. Co-immunoprecipitation assays in WI38 fibroblasts and in BRG1-/- SW13 cells showed that endogenous HIC1 and ARID1A proteins interact in a BRG1-dependent manner. Furthermore, we demonstrate that HIC1 does not interact with BRM. Finally, sequential chromatin immunoprecipitation (ChIP-reChIP) experiments demonstrated that HIC1 represses E2F1 through the recruitment of anti-proliferative SWI/SNF complexes containing ARID1A.

  12. 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. PMID:11700659

  13. Algae Reefs in Shark Bay, Western Australia, Australia

    Science.gov (United States)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  14. 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...

  15. Evaluation of hydrological balance and its variability in arid and semi-arid regions of Eurasia from ECMWF 15 year reanalysis

    Science.gov (United States)

    Yatagai, Akiyo

    2003-10-01

    Hydrometeorological cycles over arid and semi-arid regions in mid-latitude Eurasia (the Silk Road region) were investigated using meteorological reanalysis data for the period 1979-93, available from the European Centre for Medium-range Weather Forecasts (ECMWF).Results show that seasonal changes of moisture balance in Turkey and central Asia, hereafter referred to as the western region, differ from those in the Taklimakan Desert and Loess Plateau, hereafter referred to as the eastern region. Here, we equate evaporation minus precipitation with the divergence field of the vertically integrated water vapour flux. In the western region, precipitation and positive convergence C of moisture primarily occurs during October-March. In contrast, the eastern region receives precipitation and has its positive C occurring during June-August. As a result, the eastern region has nearly simultaneous seasonal peaks in precipitation P and evapotranspiration E, whereas the western region has minimum P and maximum E in summer.The main annual moisture route for the Silk Road region is from the west to east; however, moisture also comes from the north in July. Over Turkey, moisture arrives from the west and south. In central Asia, however, most of the moisture comes from the west, the convergence peaks in March, and moisture from the south and west is also greater during this month. In the Loess Plateau, moisture enters from the west, the north, and the south, and exits to the east. In July, the peak precipitation and convergence season, all moisture flows are greater for the entire region, and a large influx of moisture from the south occurs during the summer season. The moisture from the south, the monsoonal flow, has a large interannual variability. Copyright

  16. 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.

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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 ...

  1. Simulation of multimedia transfer and fate of endosulfan in semi-arid area: A case study in Lanzhou, a valley-basin city in Western China%半干旱地区典型POPs硫丹环境多介质迁移归趋模拟研究——以兰州河谷盆地为例

    Institute of Scientific and Technical Information of China (English)

    田慧; 郭强; 方利江; 毛潇萱; 黄韬; 吴军年; 马建民; 高宏

    2013-01-01

    Taking Lanzhou as the study area, a level Ⅲ fugacity model was applied to simulate the concentration distribution of two endosulfan isoraers in five environmental compartments including air, water, soil, sediment and vegetation. Meanwhile, the transfer fluxes between different compartments were analyzed in order to identify main transfer process. In addition, the reliability of this model was studied by comparing modeling results with observational data. For the model uncertainty, twenty parameters of the model were tested and the key parameters were identified using sensitivity analysis, and the uncertainty of these key parameters was estimated. The study results showed that the soil, vegetation and sediment compartments were the main reservoirs of endosulfan in Lanzhou area. Furthermore, the main input sources of endosulfan in the study area were the air inflow and use of pesticides, while the soil degradation and air advection outflow were the major routes for endosulfan depletion in the study area. The study results also indicated that the physical and chemical properties of endosulfan, such as Henry's Law Constant and AOW , as well as the environmental parameters including organic carbon content of sediment and soil had a significant influence on the model sensitivity. The reliability of the model was verified by the agreement between calculated and measured concentrations with the log-scale differences within an order of magnitude. This case study showed that the developed model was suitable for simulating the multimedia transfer and fate of endosulfan in the semi-arid Lanzhou area.%以硫丹为研究对象,利用三级多介质逸度模型,对硫丹在半干旱的兰州河谷盆地大气、水体、土壤、沉积物和植物相中的浓度分布进行模拟研究;对硫丹在研究区环境多介质问的迁移通量进行分析,确定其在环境中的主要迁移过程;并结合实际监测数据,对模型的可靠性进行验证;

  2. 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...

  3. Thermal and water management in irrigating lands in the arid and semi-arid regions

    International Nuclear Information System (INIS)

    Excess heat and scarcity of water are the two major problems, which are usually encountered in irrigating lands especially in the arid and semi-arid regions. This paper introduces a technical approach of managing agricultural lands in the arid and semi arid regions through determination of daily water requirement and amount of heat the land is being exposed at various meteorological conditions. Through setting up a mathematical model consisting of basic heat and mass transfer equations and fluid properties, daily rate of water evaporation, different modes of heat transfer such as radiation, convection and heat transfer by evaporation at a wide range relative humidities are determined. Furthermore, the analyses are performed at two different scenarios at average air velocities of 1 and 5 m/s. Our findings showed that the volume of water evaporation at relative humidity and air temperature of phi=50% and T∞=20 deg. C is 22% higher than at phi=100% and T∞=20 deg. C. Moreover, at a specified phi and T∞, the total rate of heat transfer at air velocity of 5 m/s is at least 25% higher than the total rate of heat transfer at air velocity of 1 m/s

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

    Science.gov (United States)

    Beever, Erik

    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. New Technologies to Reclaim Arid Lands User's Manual

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler

    2002-10-01

    Approximately 70 percent of all U.S. military training lands are located in arid and semi-arid areas. Training activities in such areas frequently adversely affect vegetation, damaging plants and reducing the resilience of vegetation to recover once disturbed. Fugitive dust resulting from a loss of vegetation creates additional problems for human health, increasing accidents due to decreased visibility, and increasing maintenance costs for roads, vehicles, and equipment. Under conventional technologies to mitigate these impacts, it is estimated that up to 35 percent of revegetation projects in arid areas will fail due to unpredictable natural environmental conditions, such as drought, and reclamation techniques that were inadequate to restore vegetative cover in a timely and cost-effective manner. New reclamation and restoration techniques are needed in desert ranges to help mitigate the adverse effects of military training and other activities to arid-land environments. In 1999, a cooperative effort between the U.S. Department of Energy (DOE), the US. Department of Defense (DoD), and selected university scientists was undertaken to focus on mitigating military impacts in arid lands. As arid lands are impacted due to DoD and DOE activities, biological and soil resources are gradually lost and the habitat is altered. A conceptual model of that change in habitat quality is described for varying levels of disturbance in the Mojave Desert. As the habitat quality degrades and more biological and physical resources are lost from training areas, greater costs are required to return the land to sustainable levels. The purpose of this manual is to assist land managers in recognizing thresholds associated with habitat degradation and provide reclamation planning and techniques that can reduce the costs of mitigation for these impacted lands to ensure sustainable use of these lands. The importance of reclamation planning is described in this manual with suggestions about

  6. Demographic processes limiting seedling recruitment in arid grassland restoration

    Science.gov (United States)

    Seeding is commonly used in plant community restoration to overcome recruitment limitations. In arid systems, seeding is a particularly important management tool because plant community recovery following disturbance is slow and often inhibited by invasive species. While important in arid systems,...

  7. 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)

  8. Herbivore-plant interactions and desertification in arid lands

    Science.gov (United States)

    Arid lands around the world have experienced or are currently experiencing degradation that is known as desertification. Animal-plant interactions that have an effect on desertification are among the most important function of animals in arid ecosystems. Desertification has been defined as land de...

  9. 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 ...

  10. 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.

  11. Issues in water resources demand and supply in arid Xinjiang, China

    Science.gov (United States)

    He, Bingyu; Zhang, Yi

    2003-07-01

    In implementing China Western Development, there is no doubt that we should pay more attention to studying the sustainable development in arid north-west regions because those areas are backward in economy and hostile in natural environment, and have strategic positions to promote the real development of western regions. Of those regions, Xinjinag has even strong potentials to have a great impact on different factors of sustainable development because it is more inland than any other western region. Particularly, it is essential for us to take advantage of even more flexibility which dominates the means of adjustment and control of water resources utilisation and management, and to give a strong back-up in government decision-making. This paper focuses on Xinjiang water resource status to propose four characteristics in Xinjiang water resources and to point out relevant existing problems. According to the internal and external environments of China Western Development, the paper analyses the impact of developing trends in Xinjiang water resources on agriculture planting, manufacturing industry production, urbanisation, ecology evolution, and natural environment changes. In addition, this paper probes several problems on supply and demand of Xinjiang water resources. Lastly, the paper relies on the perspective of sustainable development as guidance, and on the perspective of water resources value as a basic theory to propose the relevant suggestions and countermeasures in the relationship of Xinjiang water resources development to societal and economic development.

  12. Bird migration patterns in the arid southwest-Final report

    Science.gov (United States)

    Ruth, Janet M.; Felix, Rodney K.; Dieh, Robert H.

    2010-01-01

    To ensure full life-cycle conservation, we need to understand migrant behavior en route and how migrating species use stopover and migration aerohabitats. In the Southwest, birds traverse arid and mountainous landscapes in migration. Migrants are known to use riparian stopover habitats; we know less about how migrant density varies across the Southwest seasonally and annually, and how migrants use other habitat types during migratory stopover. Furthermore, we lack information about migrant flight altitudes, speeds, and directions of travel, and how these patterns vary seasonally and annually across the Southwest. Using weather surveillance radar data, we identified targets likely dominated by nocturnally migrating birds and determined their flight altitudes, speeds, directions over ground, and variations in abundance. Migrating or foraging bats likely are present across the region in some of these data, particularly in central Texas. We found that migrants flew at significantly lower altitudes and significantly higher speeds in spring than in fall. In all seasons migrants maintained seasonally appropriate directions of movement. We detected significant differences in vertical structure of migrant densities that varied both geographically within seasons and seasonally within sites. We also found that in fall there was a greater and more variable passage of migrants through the central part of the borderlands (New Mexico and west Texas); in spring there was some suggestion of greater and more variable passage of migrants in the eastern borderlands (central and south Texas). Such patterns are consistent with the existence of at least two migration systems through western North America and the use of different migration routes in spring and fall for at least some species. Using radar data and satellite land cover data, we determined the habitats with which migrants are associated during migration stopover. There were significant differences in bird densities among

  13. Evaporative fraction as an indicator of moisture condition and water stress status in semi-arid rangeland ecosystems

    OpenAIRE

    Francesco Nutini; Mirco Boschetti; Gabriele Candiani; Stefano Bocchi; Pietro Alessandro Brivio

    2014-01-01

    Rangeland monitoring services require the capability to investigate vegetation condition and to assess biomass production, especially in areas where local livelihood depends on rangeland status. Remote sensing solutions are strongly recommended, where the systematic acquisition of field data is not feasible and does not guarantee properly describing the spatio-temporal dynamics of wide areas. Recent research on semi-arid rangelands has focused its attention on the evaporative fraction (EF), a...

  14. 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.

  15. 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.

  16. 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

  17. Revision of the water-holding frogs, Cyclorana platycephala (Anura: Hylidae), from arid Australia, including a description of a new species.

    Science.gov (United States)

    Anstis, Marion; Price, Luke C; Roberts, J Dale; Catalano, Sarah R; Hines, Harry B; Doughty, Paul; Donnellan, Stephen C

    2016-01-01

    The water-holding frog, Cyclorana platycephala, occurs in the Australian arid and semi-arid zones but not in the central Australian deserts. Recent inspection of morphological variation in adults and larvae suggests that the taxon comprises three regional populations: eastern, northern and western that may each represent separate species. To assess the systematic status of these populations, we documented phylogenetic relationships using mitochondrial and nuclear DNA markers, divergence in adult and larval morphology and male advertisement call. Our molecular genetic data demonstrates that the western population of C. platycephala is not the sister taxon of eastern and northern representatives of this nominate species, as the latter two are more closely related to another morphologically distinct species, C. verrucosa. Discriminant Function Analysis of 14 morphological traits in adults and 15 in larvae showed a high degree of morphological differentiation of western versus eastern/northern C. platycephala. Calls of eastern and western populations differed in duration, pulse rate, frequency and especially in amplitude modulation pattern across the call duration. We describe the western population as a new species, whose range is contained entirely within Western Australia. In addition, we redescribe Cyclorana platycephala, quantify morphological and genetic differences between the eastern and northern populations, and conclude that these data support recognition of a single species, Cyclorana platycephala, for populations found in New South Wales, the Barkly Tablelands and south-eastern Northern Territory, Queensland and South Australia. PMID:27395600

  18. 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.

  19. Ebeling: Handbook of Indian Foods and Fibers of Arid America

    OpenAIRE

    Sutton, Mark Q

    1987-01-01

    Handbook of Indian Foods and Fibers of Arid America Walter Ebeling. Berkeley: University of California Press, 1986, 971 pp., 73 figures, 50 plates, 12 tables. Appendix, Glossary, Index, References, $65.00 (hardcover).

  20. 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)

  1. Isotopic evidence for ground water contributions to rare floods in arid zone Ephemeral Rivers

    International Nuclear Information System (INIS)

    Full text: Isotope data has shown that the ground water component ('old' water) feeding rivers during rainfall events can be more important than surface runoff. This has been established for rivers in temperate climates with perennial base flow. We report here on possibly unique isotopic and chemical evidence of ground water contributions to flood periods in major ephemeral water courses in the arid/semi-arid western Kalahari of Namibia. In the framework of a major ground water resource investigation in the area numerous samples were analysed for their isotope and chemical content. It was established that especially the shallow aquifer in the largely unconsolidated Kalahari formation which blankets the area shows clear evidence of kinetic evaporation. This evaporation signal is observed also in parts of the deeper sedimentary aquifers. During the period of this project the exceptional rainfall of the 1999-2000 season, experienced by many southern African countries, produced rare flood events in the ephemeral river system of the area of study. Flow rates in the rivers could only be estimated from water depth measurements. However, in some cases daily river water samples were collected for isotope analysis. Stable isotope, tritium and certain chemical parameters measured on these samples are presented and placed in context of available ground water data. The results suggest that a substantial proportion of the flow in the river was derived from perched ground water. This conclusion is strengthened by the fact that the river again flooded during the more normal 2000-2001 rainy period. (author)

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

    Science.gov (United States)

    Gao, Yanhong; Li, Xia; Leung, L. Ruby; Chen, Deliang; Xu, Jianwei

    2015-03-01

    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.

  3. 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)

  4. Analysis of aridity indicators in the Deliblato Sands

    Directory of Open Access Journals (Sweden)

    Kadović Ratko

    2014-01-01

    Full Text Available Deliblato Sands are located in the southern part of Banat region in Vojvodina province. According to the estimated changes of basic climate parameters in this part of the Republic of Serbia during past decades very strong rise in annual air temperatures (T was registered, an average of 0.52°C per decade. This rise in temperature increased the potential evapotranspiration (PET, which together with precipitation can increase the degree of aridity of climate in the study area. However, in the same period an increase in annual precipitation sum (P was observed, an average of about 35 mm per decade, which may somewhat slow the aridisation of desert sands. Considering the nature, origin and significance of Deliblato Sands ecosystem, the main goal of this paper is to analyse the drought and aridity index (AI = P / PET, analyse the trend of aridisation process and its possible impact on ecosystems of this special nature reserve. Aridity index analyses were performed in meteorological stations Banatski Karlovac, Vrsac and Bela Crkva for the period 1981 - 2010 at the annual values and for the growing season. Results showed that Deliblato desert sands (Banatski Karlovac stand at a higher frequency of arid years (AI < 0.65 compared to locations of Vrsac and Bela Crkva. On the other hand, the level of aridity has considerably increased during the vegetation period in desert sands as well in its surroundings. This intensified aridity is the result of considerable increase of potential evapotranspiration (PET connected to season precipitation.

  5. Monitoring restoration impacts to endemic plant communities in soil inclusions of arid environments

    Science.gov (United States)

    Louhaichi, Mounir; Pyke, David A.; Shaff, Scott E.; Johnson, Douglas E.

    2013-01-01

    Soil inclusions are small patches of soil with different properties than the surrounding, dominant soil. In arid areas of western North America, soil inclusions called slickspot soils are saltier than adjacent soil and support different types of native vegetation. Traditional sagebrush restoration efforts, such as using drills to plant seeds or herbicides to control invasive vegetation, may damage sensitive slickspot soil and supporting vegetation. USGS scientists David Pyke and Scott Shaff and collaborators monitored slickspot size and cover of endangered slickspot peppergrass for two years to see if they were affected by the application of the herbicide glyphosate or by a minimum-till drill in the Snake River Plain, ID. The researchers examined the use of aerial photographs versus on-the-ground measurements and concluded that slickspot sizes were not affected by these treatments. Remote sensing using aerial photographs proved a useful method for mapping slickspot soils.

  6. Two thousand wind pumps in the arid region of Brazil

    International Nuclear Information System (INIS)

    The North-East part of Brazil is an arid region where water pumping is of vital importance. The main strategy of the Wind Energy Group (Eolica) at the University of Pernambuco is to act as a 'catalyst' between the Brazilian government and the companies involved in wind energy. The company CONESP is a drilling company that is also responsible for choosing the appropriate pumping system and providing maintenance. CONESP already has drilled about 6,000 wells and installed 2,000 conventional windmills with piston pumps. Most of the wells have a very low capacity; thus wind pumps, having a relatively low water pumping capacity, are a suitable solution. However, one of the problems with the installed conventional wind pumps is that the drilled tube wells are not perfectly vertical, resulting in wear of the pump rod. Besides, the maintenance or replacement of the piston pump is time consuming and consequently costly. To reduce operation and maintenance costs, windmills coupled to pneumatic pumps have been developed. Examples are given of air-lift pumps and barc pumps, both using commercially available compressors. The main advantage is that there are no moving parts situated below ground level. Moreover, the windmill does not necessarily have to be placed above the well. Well and windmill can be situated up to 100 metres from each other. The starting torque of this system is also lower than the conventional wind pump. It is concluded that windmills with pneumatic pumps have a relatively low efficiency and higher investment costs compared with windmills coupled to piston pumps. However, CONESP's effort is to optimize the total performance of the pumping system. Due to the lower maintenance costs, pneumatic pumps seem to be a viable alternative to piston pumps. 7 figs., 3 refs

  7. VOCs in Non-Arid Soils Integrated Demonstration: Technology summary

    International Nuclear Information System (INIS)

    The Volatile Organic Compounds (VOCs) in Non-Arid Soils Integrated Demonstration (ID) was initiated in 1989. Objectives for the ID were to test the integrated demonstration concept, demonstrate and evaluate innovative technologies/systems for the remediation of VOC contamination in soils and groundwater, and to transfer technologies and systems to internal and external customers for use in fullscale remediation programs. The demonstration brought together technologies from DOE laboratories, other government agencies, and industry for demonstration at a single test bed. The Savannah River Site was chosen as the location for this ID as the result of having soil and groundwater contaminated with VOCS. The primary contaminants, trichlorethylene and tetrachloroethylene, originated from an underground process sewer line servicing a metal fabrication facility at the M-Area. Some of the major technical accomplishments for the ID include the successful demonstration of the following: In situ air stripping coupled with horizontal wells to remediate sites through air injection and vacuum extraction; Crosshole geophysical tomography for mapping moisture content and lithologic properties of the contaminated media; In situ radio frequency and ohmic heating to increase mobility, of the contaminants, thereby speeding recovery and the remedial process; High-energy corona destruction of VOCs in the off-gas of vapor recovery wells; Application of a Brayton cycle heat pump to regenerate carbon adsorption media used to trap VOCs from the offgas of recovery wells; In situ permeable flow sensors and the colloidal borescope to determine groundwater flow; Chemical sensors to rapidly quantify chlorinated solvent contamination in the subsurface; In situ bioremediation through methane/nutrient injection to enhance degradation of contaminants by methanotrophic bateria

  8. VOCs in Non-Arid Soils Integrated Demonstration: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The Volatile Organic Compounds (VOCs) in Non-Arid Soils Integrated Demonstration (ID) was initiated in 1989. Objectives for the ID were to test the integrated demonstration concept, demonstrate and evaluate innovative technologies/systems for the remediation of VOC contamination in soils and groundwater, and to transfer technologies and systems to internal and external customers for use in fullscale remediation programs. The demonstration brought together technologies from DOE laboratories, other government agencies, and industry for demonstration at a single test bed. The Savannah River Site was chosen as the location for this ID as the result of having soil and groundwater contaminated with VOCS. The primary contaminants, trichlorethylene and tetrachloroethylene, originated from an underground process sewer line servicing a metal fabrication facility at the M-Area. Some of the major technical accomplishments for the ID include the successful demonstration of the following: In situ air stripping coupled with horizontal wells to remediate sites through air injection and vacuum extraction; Crosshole geophysical tomography for mapping moisture content and lithologic properties of the contaminated media; In situ radio frequency and ohmic heating to increase mobility, of the contaminants, thereby speeding recovery and the remedial process; High-energy corona destruction of VOCs in the off-gas of vapor recovery wells; Application of a Brayton cycle heat pump to regenerate carbon adsorption media used to trap VOCs from the offgas of recovery wells; In situ permeable flow sensors and the colloidal borescope to determine groundwater flow; Chemical sensors to rapidly quantify chlorinated solvent contamination in the subsurface; In situ bioremediation through methane/nutrient injection to enhance degradation of contaminants by methanotrophic bateria.

  9. 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.

  10. 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)

  11. 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.

  12. Forecasting the Depletion of Transboundary Groundwater Resources in Hyper-Arid Environments

    Science.gov (United States)

    Mazzoni, A.; Heggy, E.

    2014-12-01

    The increase in awareness about the overexploitation of transboundary groundwater resources in hyper-arid environments that occurred in the last decades has highlighted the need to better map, monitor and manage these resources. Climate change, economic and population growth are driving forces that put more pressure on these fragile but fundamental resources. The aim of our approach is to address the question of whether or not groundwater resources, especially non-renewable, could serve as "backstop" water resource during water shortage periods that would probably affect the drylands in the upcoming 100 years. The high dependence of arid regions on these resources requires prudent management to be able to preserve their fossil aquifers and exploit them in a more sustainable way. We use the NetLogo environment with the FAO Aquastat Database to evaluate if the actual trends of extraction, consumption and use of non-renewable groundwater resources would remain feasible with the future climate change impacts and the population growth scenarios. The case studies selected are three: the Nubian Sandstone Aquifer System, shared between Egypt, Libya, Sudan and Chad; the North Western Sahara Aquifer System, with Algeria, Tunisia and Libya and the Umm Radhuma Dammam Aquifer, in its central part, shared between Saudi Arabia, Qatar and Bahrain. The reason these three fossil aquifers were selected are manifold. First, they represent properly transboundary non-renewable groundwater resources, with all the implications that derive from this, i.e. the necessity of scientific and socio-political cooperation among riparians, the importance of monitoring the status of shared resources and the need to elaborate a shared management policy. Furthermore, each country is characterized by hyper-arid climatic conditions, which will be exacerbated in the next century by climate change and lead to probable severe water shortage periods. Together with climate change, the rate of population

  13. Diagnosis of GLDAS LSM based aridity index and dryland identification.

    Science.gov (United States)

    Ghazanfari, Sadegh; Pande, Saket; Hashemy, Mehdy; Sonneveld, Ben

    2013-04-15

    The identification of dryland areas is crucial for guiding policy aimed at intervening in water-stressed areas and addressing the perennial livelihood or food insecurity of these areas. However, the prevailing aridity indices (such as UNEP aridity index) have methodological limitations that restrict their use in delineating drylands and may be insufficient for decision-making frameworks. In this study, we propose a new aridity index based on based on 3 decades of soil moisture time series by accounting for site-specific soil and vegetation that partitions precipitation into the competing demands of evaporation and runoff. Our proposed aridity index is the frequency at which the dominant soil moisture value at a location is not exceeded by the dominant soil moisture values in all of the other locations. To represent the dominant spatial template of the soil moisture conditions, we extract the first eigenfunction from the empirical orthogonal function (EOF) analysis from 3 GLDAS land surface models (LSMs): VIC, MOSAIC and NOAH at 1 × 1 degree spatial resolution. The EOF analysis reveals that the first eigenfunction explains 33%, 43% and 47% of the VIC, NOAH and MOSAIC models, respectively. We compare each LSM aridity indices with the UNEP aridity index, which is created based on LSM data forcings. The VIC aridity index displays a pattern most closely resembling that of UNEP, although all of the LSM-based indices accurately isolate the dominant dryland areas. The UNEP classification identifies portions of south-central Africa, southeastern United States and eastern India as drier than predicted by all of the LSMs. The NOAH and MOSAIC LSMs categorize portions of southwestern Africa as drier than the other two classifications, while all of the LSMs classify portions of central India as wetter than the UNEP classification. We compare all aridity maps with the long-term average NDVI values. Results show that vegetation cover in areas that the UNEP index classifies as

  14. Ant-nest ichnofossils in honeycomb calcretes, Neogene Ogallala Formation, High Plains region of western Kansas, U.S.A.

    Science.gov (United States)

    Smith, J.J.; Platt, B.F.; Ludvigson, Greg A.; Thomasson, J.R.

    2011-01-01

    Two new ant-nest trace fossils are described from calcic sandy paleosols of the Neogene Ogallala Formation in western Kansas. The ichnofossils are preserved within and below calcrete beds weathering in positive relief as carbonate-filled casts or as cavities in negative relief. Daimoniobarax ichnogenus nov. is established for burrow systems composed of vertically tiered, horizontally oriented pancake-shaped chambers connected by predominantly vertical and cylindrical shafts ~. 0.8. cm in diameter. Ichnospecies of Daimoniobarax are differentiated based on differences in the plan view outline of chambers, shaft orientation, and junctions between chambers and shafts.Daimoniobarax nephroides ichnospecies nov. is composed of an ~. 24-76. cm long vertical sequence of distinctly lobed chambers (~. 2-20. cm wide and ~. 1. cm high) arranged along sinuous to helical shafts. Chamber shape in plan view ranges from small teardrops to larger kidney- and U-shaped forms. Shafts intersect at chamber edges such that chambers appear to bud from the central shafts. Daimoniobarax nephroides is most similar to the nests of extant seed-harvester ants of the New World genus Pogonomyrmex. Such ants are specialized granivores and prefer sandy soils in arid to semi-arid grassland and desert regions.Daimoniobarax tschinkeli ichnospecies nov. is ~. 30-80. cm in vertical extent. Chambers (~. 2-30. cm wide and ~. 1. cm high) are circular to elongate or pseudopodial in plan view. Vertical shafts are straight to slightly sinuous and intersect most often toward the center of the chambers. The generalized architecture of D. tschinkeli is similar to that of the nests or nest portions of several extant ant genera, though it does not closely resemble any known modern nest.Ant ichnofossils provide valuable information on hidden biodiversity, paleohydrologic regimes, paleopedogenic processes, and paleoclimate during the time of nest occupation. Depth-related changes in chamber size and vertical spacing

  15. Prioritization of sub-watersheds in semi arid region, Western Maharashtra, India using Geographical Information System

    Directory of Open Access Journals (Sweden)

    Abhijit M.Zende

    2013-10-01

    Full Text Available - The study area is one of the sub-river basin of Krishna river, covering an area of 3035 km² and lies in west part of Maharashtra state bounded by Latitude 16055’ to 17028’ N and Longitude 74020’ to 74040’ E. Poor soil cover, sparse vegetation, erratic rainfall and lack of soil moisture characterize the study area for most part of the year. Due to unavailability/poor managed of surface water storage structures, more than 50% area depends upon groundwater for their daily needs. Recurring drought coupled with increase in ground water exploitation results in decline in the ground water level. So the entire study area has been further divided into 9 sub-watersheds named SWS1 to SWS9, ranging in geographical area from 76 km² to 492 km² and has been taken up for prioritization based on morphometric analysis using Geographical information system (GIS and remote sensing techniques. The drainage density of sub-watersheds varies between 2.07 to 3.26 km/km² and low drainage density values of sub-watershed SWS5 indicates that it has highly resistant, impermeable subsoil material with dense vegetative cover and low relief. The elongation ratio varies from 0.2 to 0.35 which indicates low relief and gentle ground slope. The high value of circularity ratio for SWS 8 sub-watershed 0.6 indicates the late maturity stage of topography. This anomaly is due to diversity of slope, relief and structural conditions prevailing in this sub-watershed. The compound parameter values are calculated and the sub-watershed with the lowest compound parameter is given the highest priority. The sub-watershed SWS3 has a minimum compound parameter value of 1.68 and SWS 8 has a maximum compound parameter 3.08. Hence it should be provided with immediate soil conservation measures because sedimentation is the major problem for surface water storage structures.

  16. Environmental isotope studies in the arid regions of Western Rajasthan, India

    International Nuclear Information System (INIS)

    An environmental isotope study carried out along an 'identified' buried river course in Jaisalmer showed that its expected head water connection with present day Himalayan sources to be very remote. The groundwater along the course is old as indicated by absence of tritium and low carbon-14 values. In an effort to understand the contribution of canal waters and return flow of irrigation waters to the groundwater and related problems in the command area of a large irrigation project, the area affected by canal water could be delineated. The ground water salinity is attributed both to the uplift of local saline groundwaters caused by water logging in the area as well as to evaporation from shallow groundwaters. Deep fresh groundwater is available in many parts in the desert region, which have been identified as palaeowaters: over exploitation of these old waters in some areas is indicated by their mixing with shallow groundwaters. Modem recharge is possible in the southern part of the state where comparatively higher precipitation is received. (author)

  17. Enclosing the commons: reasons for the adoption and adaptation of enclosures in the arid and semi-arid rangelands of Chepareria, Kenya.

    Science.gov (United States)

    Wairore, John N; Mureithi, Stephen M; Wasonga, Oliver V; Nyberg, Gert

    2015-01-01

    The adoption and adaptation of enclosures in the arid and semi-arid rangelands of sub-Saharan Africa is driven and sustained by a combination of factors. However, reviews indicate that these factors cannot be generalized, as they tend to be case specific. A study was therefore conducted to explore the history and reasons for enclosure establishment in Chepareria, a formerly degraded communal rangeland in north-western Kenya. While Vi-Agroforestry Organization accounting for 52.5 % was the main source of knowledge on enclosure establishment; it has now emerged that rangeland enclosures among the Pokot pastoral community existed prior to land management interventions by Vi- Agroforestry. Results indicated that there are three categories of enclosures which were established for boundary demarcation, provide grazing reserves, enable proper land management, facilitate crop cultivation in a pastoral setup and to curb land degradation. The role of self-trigger [accounting for most of the spontaneous enclosures (73.5 %)] indicates the continued establishment and expansion of areas under enclosure management as private land ownership accounting for 51.7 % of enclosure tenure continues to gain momentum in Chepareria. While rangeland enclosures in Chepareria were mainly established for boundary demarcation, to alleviate pasture scarcity and enable proper management of formerly degraded areas; they have facilitated land restoration and rehabilitation by increasing flexibility in land, fodder and livestock management amongst agro-pastoralists in Chepareria over the last three decades. To ensure that rehabilitated areas do not revert to their previously degraded state; technical interventions are needed to allow for a more intensive use of rangeland resources within enclosed areas. PMID:26543730

  18. 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)

  19. Predicted performance of clay-barrier landfill covers in arid and semi-arid environments.

    Science.gov (United States)

    Sadek, S; Ghanimeh, S; El-Fadel, M

    2007-01-01

    Conventional landfill cover systems for municipal solid waste include low-permeability compacted clay barriers to minimize infiltration into the landfilled waste. Such layers are vulnerable in climates where arid to semi-arid conditions prevail, whereby the clay cover tends to desiccate and crack, resulting in drastically higher infiltration, i.e., lower cover efficiency. To date, this phenomenon, which has been reported in field observations, has not been adequately assessed. In this paper, the performance of a cover system solely relying on a clay barrier was simulated using a numerical finite element formulation to capture changes in the clay layer and the corresponding modified hydraulic characteristics. The cover system was guided by USEPA Subtitle-D minimum requirements and consisted of a clay layer underlying a protective vegetated soil. The intrinsic characteristics of the clay barrier and vegetative soil cover, including their saturated hydraulic conductivities and their soil-water characteristic curves, were varied as warranted to simulate intact or "cracked" conditions as determined through the numerical analyses within the proposed methodology. The results indicate that the levels of percolation through the compromised or cracked cover were up to two times greater than those obtained for intact covers, starting with an intact clay hydraulic conductivity of 10(-5)cm/s. PMID:16987648

  20. 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

  1. Non-isothermal water flow in the vadose zone of arid and semi-arid environments

    Science.gov (United States)

    Mallants, Dirk; Gerke, Kirill; Cook, Peter

    2013-04-01

    In desert environments thermally-driven vapour flow can be an important component of the total water flux in soils. As such, vapour flow can have considerable impact on recharge estimation, with small errors in soil water flow rates resulting in relatively larger errors in the recharge estimates since recharge is a very small fraction of rainfall. The additional effects of vegetation and temperature contributions may also impact soil water movement and thus calculated recharge rates in arid and semi-arid vadose zones. Currently most methods for estimating large-scale recharge rates do not consider these various processes, which adds an unknown degree of uncertainty to recharge estimation. The HYDRUS-1D numerical simulator was used to simulate coupled isothermal liquid, isothermal vapour, non-isothermal liquid and vapour flow, and heat flow in deep variably saturated vadose zones. The considered climatic conditions are characteristic of central Australia with approximate mean annual precipitation and potential evapotranspiration rates of 300 and 3000 mm, respectively. A time series of 130 years of daily climate data provides the upper boundary conditions. Groundwater recharge under highly erratic rainfall conditions is hypothesized to be primarily episodic and linked to flood events which may be significant only once every few years. The combined effect of vegetation and temperature on water flow and soil water redistribution is discussed for both vegetated and bare soils.

  2. Seed viability and germination success of Acacia tortilis along land-use and aridity gradients in the Eastern Sahara.

    Science.gov (United States)

    Andersen, Gidske Leknæs; Krzywinski, Knut; Gjessing, Håkon K; Pierce, Richard Holton

    2016-01-01

    Our study focuses on the keystone species Acacia tortilis and is the first to investigate the effect of domestic ungulates and aridity on seed viability and germination over an extensive part of the Eastern Sahara. Bruchids infest its seeds and reduce their viability and germination, but ingestion by ruminant herbivores diminishes infestation levels and enhances/promotes seed viability and germination. The degree of these effects seems to be correlated with animal body mass. Significantly reduced numbers of wild ruminant ungulates have increased the potential importance of domestic animals and pastoral nomadism for the functionality of arid North African and Middle Eastern ecosystems. We sampled seeds (16,543) from A. tortilis in eight areas in three regions with different aridity and land use. We tested the effect of geography and sampling context on seed infestation using random effects logistic regressions. We did a randomized and balanced germination experiment including 1193 seeds, treated with different manure. Germination time and rates across geography, sampling context, and infestation status were analyzed using time-to-event analyses, Kaplan-Meier curves and proportional hazards Cox regressions. Bruchid infestation is very high (80%), and the effects of context are significant. Neither partial infestation nor adding manure had a positive effect on germination. There is a strong indication that intact, uningested seeds from acacia populations in the extremely arid Western Desert germinate more slowly and have a higher fraction of hard seeds than in the Eastern Desert and the Red Sea Hills. For ingested seeds in the pastoralist areas we find that intact seeds from goat dung germinate significantly better than those from camel dung. This is contrary to the expected body-mass effect. There is no effect of site or variation in tribal management. PMID:26811790

  3. Western Nuclear Science Alliance

    International Nuclear Information System (INIS)

    The Western Nuclear Science Alliance (WNSA) was formed at Oregon State University (OSU) under the DOE Innovations in Nuclear Infrastructure and Education (INIE) program in 2002. The primary objective of the INIE program is to strengthen nuclear science and engineering programs at the member institutions and to address the long term goal of the University Reactor Infrastructure and Education Assistance Program. WNSA has been very effective in meeting these goals. The infrastructure at several of the WNSA university nuclear reactors has been upgraded significantly, as have classroom and laboratory facilities for Nuclear Engineering, Health Physics, and Radiochemistry students and faculty. Major nuclear-related education programs have been inaugurated, including considerable assistance by WNSA universities to other university nuclear programs. Research has also been enhanced under WNSA, as has outreach to pre-college and college students and faculty. The INIE program under WNSA has been an exceptional boost to the nuclear programs at the eight funded WNSA universities. In subsequent years under INIE these programs have expanded even further in terms of new research facilities, research reactor renovations, expanded educational opportunities, and extended cooperation and collaboration between universities, national laboratories, and nuclear utilities.

  4. 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.

  5. Arid Climate Landscape Evolution and the Pediment Problem

    Science.gov (United States)

    Strudley, M. W.; Murray, A. B.; Haff, P. K.

    2003-12-01

    Although widely disseminated throughout many different climatic environments, pediments, or gently sloping, laterally extensive surfaces characterized by a thin veneer of alluvium covering bedrock, are particularly well developed in granitic desert locales such as the Mojave and Colorado Deserts in southern California and the Sonoran Desert in western Arizona. These features form a transitional zone within the piedmont of many exposed batholithic mountainous bodies, separating a zone of bare bedrock erosion in the steep mountain mass from a depositional zone in the alluvial basin. Well developed pediments in granitic environments commonly contain bedrock outcroppings (tors or inselbergs) that may remain uncovered indefinitely and sharp slope discontinuities at the piedmont junction separating the pediment surface from the mountain mass. Pediments have been the focus of debate in geomorphic circles for over half a century. While some geomorphologists have proposed that pediments and their associated tor fields represent unearthed relict landforms, others propose unique modes of sediment transport that form and maintain the beveled form of pediment surfaces. We hypothesize that a simple relationship between bedrock weathering and alluvial thickness could explain this range of enigmatic features and phenomena, a relationship that Anderson (2002) incorporates in his proposed explanation for high alpine surfaces and tors. Field observations suggest that the transformation of bedrock to regolith is most rapid with a finite covering of regolith. This weathering rule, combined with a simple set of sediment transport rules provides a mechanism through which pediment surfaces are produced. We examine the development of pediment surfaces and associated features using a 3D numerical, distributed-parameter landscape evolution model incorporating the most pertinent landscape development processes acting in arid regions. Temporally and spatially variable rainfall (storm size

  6. Supply Chain Management of Fresh Produce: Melons in Western China

    OpenAIRE

    Zhang, Yanrong; Wei, Sherrie; Qiao, Zhixia

    2006-01-01

    The western part of China has a long history and reputation of growing a variety of quality melons largely due to its semi arid agronomic environment. In the past decade, the industry suffered from the interrelated issues of unreliable quality and intense price competition. Even though both the government and supply chain stakeholders are aware of the problems, there is a need to look at the issues from a supply chain perspective and new ways of managing the melon supply chains are to be expl...

  7. 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

  8. Preparation for upgrading western subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, R.W.; Cha, C.Y.; Sheesley, D.C.

    1990-11-01

    The objective of this project was to establish the physical and chemical characteristics of western coal and determine the best preparation technologies for upgrading this resource. Western coal was characterized as an abundant, easily mineable, clean, low-sulfur coal with low heating value, high moisture, susceptibility to spontaneous ignition, and considerable transit distances from major markets. Project support was provided by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The research was conducted by the Western Research Institute, (WRI) in Laramie, Wyoming. The project scope of work required the completion of four tasks: (1) project planning, (2) literature searches and verbal contacts with consumers and producers of western coal, (3) selection of the best technologies to upgrade western coal, and (4) identification of research needed to develop the best technologies for upgrading western coals. The results of this research suggest that thermal drying is the best technology for upgrading western coals. There is a significant need for further research in areas involving physical and chemical stabilization of the dried coal product. Excessive particle-size degradation and resulting dustiness, moisture reabsorption, and high susceptibility to spontaneous combustion are key areas requiring further research. Improved testing methods for the determination of equilibrium moisture and susceptibility to spontaneous ignition under various ambient conditions are recommended.

  9. Dry-Matter Production in Irrigated Crops in the Arid Mediterranean Zone

    International Nuclear Information System (INIS)

    The water balance equation for crops is applied to research on the water requirements of crops in the arid Mediterranean zone and the effectiveness of the water according to the season. The neutron probe is used to determine variations in the groundwater reserve. The method used results in an error in estimation of the term ΔR (variations in groundwater reserves in the zone penetrated by the roots) not exceeding 10 mm of water. For fodder crops which undergo successive cuttings (sorghum, lucerne) the method used disclosed some outstanding facts, which may be confirmed by theoretical study of the equation for the production of dry matter. These results show in particular that: There is in fact a simple relationship between the yield and the ETR water consumption (true evapotranspiration) > Nevertheless, for a given quantity of water added to the soil (rainfall + drainage), the demand made by the crop on the groundwater reserves varies in particular with the level of these reserves and with the root development; An important finding is that the maximum yield, obtained when ETR= ETP (potential evapotranspiration) , decreases as the ETP values increase. For large ETP values, when the light factor does not limit photosynthesis, the product (ETP x yield) is relatively constant. Therefore, high potential evapotranspiration values appear to be an important limiting factor in the production of dry matter in the arid Mediterranean zone. The paper concludes by suggesting a number of agronomic solutions. (author)

  10. 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.

  11. 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)

  12. 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.

  13. Mediterranean semi-arid systems-sensitivity and adaptation

    International Nuclear Information System (INIS)

    The semi-arid areas of the Mediterranean are sensitive to climate change as they are located. In many cases, between two different systems, the arid system and the Mediterranean sub-humid system. A number of quick response ecogeomorphological variables were monitored along a climatic transect in Israel, running from west to east, covering an annual rainfall range of 700-100mm. The relationships of climatic conditions-available water soil properties overland flow erosion, were investigates. Soil samples were taken from open areas between shrubs and overland flow was monitored in posts of 7, 14 and 21 m in length (3m width). (Author)

  14. Precambrian-Cambrian Sedimentology, Stratigraphy, and Paleontology in the Great Basin (Western United States)

    OpenAIRE

    Sappenfield, Aaron Dale

    2015-01-01

    Thick accumulations of Neoproterozoic and early Phanerozoic strata are distributed throughout much of the arid continental interior of western North America, providing an expansive and well-exposed archive of this important time in Earth’s history. The information presented herein supplements evaluations regarding the utility and limitations of this archive by providing an integrated sedimentological, paleontological, and geochronological description for Precambrian-Cambrian strata exposed i...

  15. Environmental implications of slope deposits in humid tropical africa : evidence from southern cameroon and western kenya

    OpenAIRE

    Kadomura, Hiroshi; Hori, Nobuyuki

    1990-01-01

    Radiocarbon-dated stratigraphic sequence of slope deposits in the humid, now and formerly forested areas of Southern Cameroon and similar stratigraphy in Western Kenya suggest following environmental history: 1) widespread savannization or steppization of closed forests during the Last Glacial Maximum arid phase in the low latitudes; 2) return of humid climates followed by forest reestablishment in the early to middle Holocene (>8,500-3,000 yr B.P.), and 3) anthropogenic transformation of upp...

  16. 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

  17. 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

  18. Effects of environmental conditions on soil salinity and arid region in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Ben Ahmed, C.; Ben Rouina, B.; Boukhris, M.

    2009-07-01

    The shortage of water resources of good water quality is becoming an issue in the arid and semi arid regions. for this reason, the use of water resources of marginal quality such as treated wastewater and saline groundwater has become and important consideration, particularly in arid region in Tunisia, where large quantities of saline water are used for irrigation. (Author)

  19. Population of goats related to climate in western India: an ecological assessment

    Science.gov (United States)

    Pandeya, S. C.; Solanki, G. S.

    1991-12-01

    Western India experiences arid to dry subhumid ecoclimate. Aridity increases from east to west to the Great Indian Desert or Thar Desert. The desert economy is animal based and goats are the most common livestock; density of goats increases with increase in aridity. There are large morphological variations in goats warranting the recognition of population differences throughout the region. The present investigations were therefore undertaken to see whether there are population differences and, if so, to establish the populations on a sound ecological basis. Eleven physical measurements of the animals were made in the fields of western India in a total of 518 animals (255 adults). Five populations were initially segregated by means of a scatter diagram. Population differences were confirmed by mathematical treatments using analysis of variance (one-way and two-way) and Students-Newman-Keuls test, which yields a critical comparison among means. Discriminant analysis was used to determine whether the goat populations differed significantly between the five climo-edaphic-vegetational zones. Each population was designated according to the locality having the greatest density as: POP1Ku, POP2Sa, POP3Jh, POP4Ga, POP5Pa. The five populations occurring in distinct climo-edaphic-vegetational zones or ecological niches in western India may be referred to as ecotypes.

  20. 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 ...

  1. What Is Western Civilization?

    Science.gov (United States)

    Birken, Lawrence

    1992-01-01

    Discusses opposing tendencies in the interpretation of Western Civilization. Describes the expanded definition that includes Byzantine and Islamic cultures as heirs of the Greco-Roman cultures. Suggests that a limited definition of Western culture will facilitate a problems approach, emphasize diversity among cultures, and integrate the classical…

  2. Vegetation mosaics in arid Australia: linked roles for climate and soils

    Science.gov (United States)

    Dunkerley, D.

    2012-04-01

    It is widely considered that quasi-regular patterns in dryland soils and vegetation reflect a process of self-organisation. In such a view, the spatial patterns emerge from multiple interactions and feedbacks among the elements of the ecogeomorphic system. In arid western NSW, Australia, key elements affecting the self-organisation of strongly banded vegetation appear to include the extreme climatic variability (related to ENSO and other global climate phenomena) and the geomorphic history of the landscape, which involves major glacial-period accessions of exotic aeolian clays of the illite family, which exhibit very marked shrink-swell behaviour. The latter may be a prerequisite for pattern emergence, and the former a key driver of emergence. A cellular model of pattern emergence was driven by a timeseries of annual rainfalls exhibiting occasional marked wet La Niña years and also multi-year El Niño droughts, in order to explore how this climatic driver affects pattern emergence. Importantly, the model incorporated the effects of drying and contraction of the deeper subsoils during multi-year droughts. In the field, extreme soil desiccation is seen to result in widespread tension cracking and collapse of the surface soils into voids in the more clay rich, and more strongly contracted, subsoil. The collapse features maintain the water trapping efficiency of the vegetation groves even when the plant cover has declined greatly. Trapping efficiency remains low within intergroves, because the subsoils there are always relatively dry, owing to their impermeable soil surfaces. Modelling excluding soil collapse during drought showed much greater loss of groves and resultant changes in grove spacing that is not seen in long-term field monitoring data. This suggests that the variability of annual rainfalls (and not just the average climatic aridity) may actually confer stability on the banded vegetation communities via a little-explored linkage of soil and climatic

  3. Relative importance of evapotranspiration variability in a semi-arid urban environment

    Science.gov (United States)

    Shields, C. A.; Tage, C. L.; Beighley, R. E.

    2008-12-01

    In semi-arid ecosystems, evapotranspiration (ET) is a significant portion of the water balance, sometimes accounting for over 70 percent of the annual water balance. In these water limited systems, spatial and temporal patterns of ET have large impacts on streamflow variability and storm response. In the western U.S., increasing human populations are resulting in an expansion of urban land uses in semi-arid areas. Urbanization may affect the local water balance in several ways. Replacing vegetation with impervious surface may decrease ET, as well as increasing storm runoff and annual streamflow. At the same time, importation of water from outside a drainage basin may increase opportunities for ET within the drainage area if this water is used to water lawns or other outdoor vegetation. Given the highly heterogeneous and fragmented nature of urban environments, these changes in ET are expected to show a high level of both spatial and temporal variability. We use the Regional Hydrologic Simulation System (RHESSys) to simulate ET and streamflow in the Mission Creek catchment in Santa Barbara, CA. This modeling relied heavily on input data collected through the Santa Barbara Coastal (SBC) LTER site. We consider a range of different urban development and climate scenarios to estimate how urbanization may alter ET and its impacts on streamflow. Results show that ET is highly variable on both an interannual and seasonal basis and its influence on storm flow response varies on both these scales. Results also show that urbanization is likely to significantly alter ET, with consequences for streamflow. The effect of urbanization is spatially variable and emphasizes the relative importance of different regions of the catchment, such as the riparian zone.

  4. Isotopic evidence for ground water contributions to rare floods in arid zone ephemeral rivers

    International Nuclear Information System (INIS)

    Full text: Isotope data has shown that the ground water component ('old' water) feeding rivers during rainfall events can be more important than surface runoff (Sklash et al. 1976). This has been established for rivers in temperate climates with perennial base flow. We report here on possibly unique isotopic and chemical evidence of ground water contributions to flood periods in major ephemeral water courses in the arid/semi-arid western Kalahari of Namibia. In the framework of a major ground water resource investigation in the area numerous samples were analysed for their isotope and chemical content. It was established that especially the shallow aquifer in the largely unconsolidated Kalahari formation which blankets the area shows clear evidence of kinetic evaporation. This evaporation signal is observed also in parts of the deeper sedimentary aquifers. During the period of this project the exceptional rainfall of the 1999-2000 season, experienced by many southern African countries, produced rare flood events in the ephemeral river system of the area of study. Flow rates in the rivers could only be estimated from water depth measurements. However, in some cases daily river water samples were collected for isotope analysis. Stable isotope, tritium and certain chemical parameters measured on these samples are presented and placed in context of available ground water data. The results suggest that a substantial proportion of the flow in the river was derived from perched ground water. This conclusion is strengthened by the fact that the river again flooded during the more normal 2000-2001 rainy period. (author)

  5. Rain and channel flow supplements to subsurface water beneath hyper-arid ephemeral stream channels

    Science.gov (United States)

    Kampf, Stephanie K.; Faulconer, Joshua; Shaw, Jeremy R.; Sutfin, Nicholas A.; Cooper, David J.

    2016-05-01

    In hyper-arid regions, ephemeral stream channels are important sources of subsurface recharge and water supply for riparian vegetation, but few studies have documented the subsurface water content dynamics of these systems. This study examines ephemeral channels in the hyper-arid western Sonoran Desert, USA to determine how frequently water recharges the alluvial fill and identify variables that affect the depth and persistence of recharge. Precipitation, stream stage, and subsurface water content measurements were collected over a three-year study at six channels with varying contributing areas and thicknesses of alluvial fill. All channels contain coarse alluvium composed primarily of sands and gravels, and some locations also have localized layers of fine sediment at 2-3 m depth. Rain alone contributed 300-400 mm of water input to these channels over three years, but water content responses were only detected for 36% of the rain events at 10 cm depth, indicating that much of the rain water was either quickly evaporated or taken up by plants. Pulses of water from rain events were detected only in the top meter of alluvium. The sites each experienced ⩽5 brief flow events, which caused transient saturation that usually lasted only a few hours longer than flow. These events were the only apparent source of water to depths >1 m, and water from flow events quickly percolated past the deepest measurement depths (0.5-3 m). Sustained saturation in the shallow subsurface only developed where there was a near-surface layer of finer consolidated sediments that impeded deep percolation.

  6. 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.

  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. 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.

  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. 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

  11. 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

  12. 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

  13. 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

  14. Causes of early Holocene desertification in arid central Asia

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Liya [Lanzhou University, Key Laboratory of Western China' s Environmental System, Lanzhou, Gansu (China); University of Kiel, Institute of Geosciences, Kiel (Germany); Chen, Fahu [Lanzhou University, Key Laboratory of Western China' s Environmental System, Lanzhou, Gansu (China); Morrill, Carrie [University of Colorado, Cooperative Institute for Research in Environmental Sciences, Boulder, CO (United States); NOAA' s National Climatic Data Center, Paleoclimatology Branch, Boulder, CO (United States); Otto-Bliesner, Bette L.; Rosenbloom, Nan [National Center for Atmospheric Research, Climate and Global Dynamics Division, Boulder, CO (United States)

    2012-04-15

    Paleoclimate records of effective moisture (precipitation minus evaporation, or P-E) show a dry (low effective moisture) period in mid-latitude arid/semi-arid central Asia during the early Holocene (11,000-8,000 years ago) relative to the middle and late Holocene, in contrast to evidence for greater-than-present precipitation at the same time in the south and east Asian monsoonal areas. To investigate the spatial differences in climate response over mid-latitude central Asia and monsoonal Asia we conducted a series of simulations with the Community Climate System Model version 3 coupled climate model for the early, middle and late Holocene. The simulations test the climatic impact of all important forcings for the early Holocene, including changes in orbital parameters, the presence of the remnant Laurentide ice sheet and deglacial freshening of the North Atlantic. Model results clearly show the early Holocene patterns indicated by proxy records, including both the decreased effective moisture in arid central Asia, which occurs in the model primarily during the winter months, and the increase in summer monsoon precipitation in south and east Asia. The model results suggest that dry conditions in the early Holocene in central Asia are closely related to decreased water vapor advection due to reduced westerly wind speed and less evaporation upstream from the Mediterranean, Black, and Caspian Seas in boreal winter. As an extra forcing to the early Holocene climate system, the Laurentide ice sheet and meltwater fluxes have a substantial cooling effect over high latitudes, especially just over and downstream of the ice sheets, but contribute only to a small degree to the early Holocene aridity in central Asia. Instead, most of the effective moisture signal can be explained by orbital forcing decreasing the early Holocene latitudinal temperature gradient and wintertime surface temperature. We find little evidence for regional subsidence related to a stronger summer Asian

  15. New data on the “silver-bell cricket” (Orthoptera, Gryllidae), a forgotten and overlooked cricket subject to a high risk of extinction in western Europe

    OpenAIRE

    Cordero, P.J.; Llorente, V.

    2008-01-01

    Gryllodinus kerkennensis (Finot, 1893) presents a disjunct distribution in the Southern part of the Western Palearctic from North Africa up to Central Asia inhabiting arid, semidesert or desert land mostly associated with saline soils near water sources of lagoons or river beds depressions. The species was not recorded in Western Europe (Iberian Peninsula) since 1936 and up to now it is currently excluded from all red list books for Orthopteran conservation. In this paper w...

  16. 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)

  17. 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

  18. 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.

  19. 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.

  20. Global patterns and environmental controls of perchlorate and nitrate co-occurrence in arid and semi-arid environments

    Science.gov (United States)

    Jackson, W. Andrew; Böhlke, J. K.; Andraski, Brian J.; Fahlquist, Lynne; Bexfield, Laura; Eckardt, Frank D.; Gates, John B.; Davila, Alfonso F.; McKay, Christopher P.; Rao, Balaji; Sevanthi, Ritesh; Rajagopalan, Srinath; Estrada, Nubia; Sturchio, Neil; Hatzinger, Paul B.; Anderson, Todd A.; Orris, Greta; Betancourt, Julio; Stonestrom, David; Latorre, Claudio; Li, Yanhe; Harvey, Gregory J.

    2015-09-01

    Natural perchlorate (ClO4-) is of increasing interest due to its wide-spread occurrence on Earth and Mars, yet little information exists on the relative abundance of ClO4- compared to other major anions, its stability, or long-term variations in production that may impact the observed distributions. Our objectives were to evaluate the occurrence and fate of ClO4- in groundwater and soils/caliche in arid and semi-arid environments (southwestern United States, southern Africa, United Arab Emirates, China, Antarctica, and Chile) and the relationship of ClO4- to the more well-studied atmospherically deposited anions NO3- and Cl- as a means to understand the prevalent processes that affect the accumulation of these species over various time scales. ClO4- is globally distributed in soil and groundwater in arid and semi-arid regions on Earth at concentrations ranging from 10-1 to 106 μg/kg. Generally, the ClO4- concentration in these regions increases with aridity index, but also depends on the duration of arid conditions. In many arid and semi-arid areas, NO3- and ClO4- co-occur at molar ratios (NO3-/ClO4-) that vary between ∼104 and 105. We hypothesize that atmospheric deposition ratios are largely preserved in hyper-arid areas that support little or no biological activity (e.g. plants or bacteria), but can be altered in areas with more active biological processes including N2 fixation, N mineralization, nitrification, denitrification, and microbial ClO4- reduction, as indicated in part by NO3- isotope data. In contrast, much larger ranges of Cl-/ClO4- and Cl-/NO3- ratios indicate Cl- varies independently from both ClO4- and NO3-. The general lack of correlation between Cl- and ClO4- or NO3- implies that Cl- is not a good indicator of co-deposition and should be used with care when interpreting oxyanion cycling in arid systems. The Atacama Desert appears to be unique compared to all other terrestrial locations having a NO3-/ClO4- molar ratio ∼103. The relative

  1. 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. 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 model approach within a value chain analysis process to evaluate program effectiveness and impacts at

  2. Climate Warming Threatens Semi-arid Forests in Inner Asia

    Science.gov (United States)

    WU, X.; Liu, H.; Qi, Z.; Li, X.

    2014-12-01

    A line of evidences reveal an increasing tree growth decline and tree mortality mainly attributable to climate warming and the warming-mediated changes in drought and other processes (such as fire and insect dynamics) in many parts of world tropical, temperate and boreal forests. However, the growth responses to climate change of the widely distributed semi-arid forests are unclear. Here, we synthetically investigate the tree growth patterns during past decades and its interannual response to climate variations in Inner Asia combining the ground truth field survey and samplings, remote sensing observations and climate data. We identified a pervasive tree growth decline since mid-1990s in semi-arid forests in Inner Asia. The widely observed tree growth decline is dominantly attributable to warming-induced water stress during pre- and early growing season. Tree growth of semi-arid forests in Inner Asia is particularly susceptible to spring warming and has been suffering a prolonged growth limitation in recent decades due to spring warming-mediated water conditions. Additionally, we identified a much slower growth rate in younger trees and a lack of tree regeneration in these semi-arid forests. The widely observed forest growth reduction and lack of tree regeneration over semi-arid forests in Inner Asia could predictably exert great effects on forest structure, regionally/globally biophysical and biochemical processes and the feedbacks between biosphere and atmosphere. Notably, further increases in forest stress and tree mortality could be reasonably expected, especially in context of the increase frequency and severity of high temperature and heat waves and changes in forest disturbances, potentially driving the eventual regional loss of current semi-arid forests. Given the potential risks of climate induced forest dieback, increased management attention to adaptation options for enhancing forest resistance and resilience to projected climate stress can be expected

  3. Computer Simulation Western

    International Nuclear Information System (INIS)

    Computer Simulation Western is a unit within the Department of Applied Mathematics at the University of Western Ontario. Its purpose is the development of computational and mathematical methods for practical problems in industry and engineering and the application and marketing of such methods. We describe the unit and our efforts at obtaining research and development grants. Some representative projects will be presented and future plans discussed. (author)

  4. Embracing Western Ways While Cleaving to Tradition

    Institute of Scientific and Technical Information of China (English)

    LuRucai

    2005-01-01

    Colorfully coiffured Chinese youth dressed in up-to-the-minute grunge listening to rock music as they walk,or sitting in a group discussing last night's NBA league match are common sights in Chind's large cities,Western,particularly stateside,youth culture is rapidly incorporating itself into everyday urban Chinese life,What does the country's youth and society in general think about this cultural omslaught?

  5. Development and use of bioenergy feedstocks for semi-arid and arid lands.

    Science.gov (United States)

    Cushman, John C; Davis, Sarah C; Yang, Xiaohan; Borland, Anne M

    2015-07-01

    Global climate change is predicted to increase heat, drought, and soil-drying conditions, and thereby increase crop sensitivity to water vapour pressure deficit, resulting in productivity losses. Increasing competition between agricultural freshwater use and municipal or industrial uses suggest that crops with greater heat and drought durability and greater water-use efficiency will be crucial for sustainable biomass production systems in the future. Agave (Agavaceae) and Opuntia (Cactaceae) represent highly water-use efficient bioenergy crops that could diversify bioenergy feedstock supply yet preserve or expand feedstock production into semi-arid, abandoned, or degraded agricultural lands, and reclaim drylands. Agave and Opuntia are crassulacean acid metabolism species that can achieve high water-use efficiencies and grow in water-limited areas with insufficient precipitation to support traditional C3 or C4 bioenergy crops. Both Agave and Opuntia have the potential to produce above-ground biomass rivalling that of C3 and C4 crops under optimal growing conditions. The low lignin and high amorphous cellulose contents of Agave and Opuntia lignocellulosic biomass will be less recalcitrant to deconstruction than traditional feedstocks, as confirmed by pretreatments that improve saccharification of Agave. Refined environmental productivity indices and geographical information systems modelling have provided estimates of Agave and Opuntia biomass productivity and terrestrial sequestration of atmospheric CO2; however, the accuracy of such modelling efforts can be improved through the expansion of field trials in diverse geographical settings. Lastly, life cycle analysis indicates that Agave would have productivity, life cycle energy, and greenhouse gas balances comparable or superior to those of traditional bioenergy feedstocks, but would be far more water-use efficient. PMID:25873672

  6. 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.

  7. Désertification des parcours arides au Maroc

    OpenAIRE

    Mahyou, H.; B. Tychon; Balaghi, R.; Mimouni, J.; Paul, R.

    2010-01-01

    Les terres de parcours naturels arides du Maroc sont des écosystèmes avec une végétation naturelle ou semi naturelle composée de steppes, d’arbustes et de prairies. Elles représentent 82% de la superficie des terres arides marocaines. Ces terres offrent des moyens de subsistance à des milliers de personnes et protègent le pays d’une désertification rapide. Malgré l’importance de ces zones fragiles, il est étonnant qu’il n’y ait, à ce jour, aucune évaluation globale de leur état et de leur ...

  8. 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.

  9. 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.

  10. Estimating large-scale evapotranspiration in arid and semi-arid systems: A multi-site study linking MODIS and Ameriflux data

    Science.gov (United States)

    A common goal for water resource managers is to ensure long-term water sustainability for increasing human populations in the arid and semi-arid southwestern United States. In these areas, estimating evapotranspiration (ET) at watershed or river-reach scales is critical in determining an amount of w...

  11. Climate risk management for water in semi–arid regions

    OpenAIRE

    Robertson, Andrew W.; Baethgen, Walter; Block, Paul; Lall, Upmanu; Sankarasubramanian, Arumugam; de Assis de Souza Filho, Francisco; Verbist, Koen

    2014-01-01

    Background: New sources of hydroclimate information based on forecast models and observational data have the potential to greatly improve the management of water resources in semi-arid regions prone to drought. Better management of climate-related risks and opportunities requires both new methods to develop forecasts of drought indicators and river flow, as well as better strategies to incorporate these forecasts into drought, river or reservoir management systems. In each case the existing i...

  12. 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

  13. 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...

  14. Désertification des parcours arides au Maroc

    Directory of Open Access Journals (Sweden)

    Mahyou, H.

    2010-01-01

    Full Text Available Desertification of Arid Rangelands in Morocco. Rangeland or natural arid pastures of Morocco are ecosystems where there is a natural or seminatural vegetation composed of steppes, shrubs and grassland. They cover about 82% of the Moroccan arid lands. These areas represent livelihoods for thousands of people and protect the country from desertification. Despite the importance of the rangelands and the threat of desertification, it is surprising that up to date there is no comprehensive assessment of their condition and their evolution, hindering any plan for desertification alleviation. However, the available information on selected pilot areas shows that these rangelands are threatened by desertification. It's associated with biodiversity loss and contributes to climate change. The leading causes of land degradation are the human actions combined with climate. The establishment of a comprehensive surveillance system based on remote sensing, biophysics and socio-economic data must be envisaged to provide policymakers with an operational tool adapted to the spatio-temporal monitoring of desertification.

  15. 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.

  16. Mutations in ARID2 are associated with intellectual disabilities.

    Science.gov (United States)

    Shang, Linshan; Cho, Megan T; Retterer, Kyle; Folk, Leandra; Humberson, Jennifer; Rohena, Luis; Sidhu, Alpa; Saliganan, Sheila; Iglesias, Alejandro; Vitazka, Patrik; Juusola, Jane; O'Donnell-Luria, Anne H; Shen, Yufeng; Chung, Wendy K

    2015-10-01

    The etiology of intellectual disabilities (ID) remains unknown for the majority of patients. Due to reduced reproductive fitness in many individuals with ID, de novo mutations account for a significant portion of severe ID. The ATP-dependent SWI/SNF chromatin modifier has been linked with neurodevelopmental disorders including ID and autism. ARID2 is an intrinsic component of polybromo-associated BAF (PBAF), the SWI/SNF subcomplex. In this study, we used clinical whole exome sequencing (WES) in proband-parent-trios to identify the etiology of ID. We identified four independent, novel, loss of function variants in ARID2 gene in four patients, three of which were confirmed to be de novo. The patients all have ID and share other clinical characteristics including attention deficit hyperactivity disorder, short stature, dysmorphic facial features, and Wormian bones. All four novel variants are predicted to lead to a premature termination with the loss of the two conservative zinc finger motifs. This is the first report of mutations in ARID2 associated with developmental delay and ID. PMID:26238514

  17. Optimum contracted-for water supply for hotels in arid coastal regions.

    Science.gov (United States)

    Lamei, A; von Münch, E; van der Zaag, P; Imam, E

    2009-01-01

    Hotels in arid coastal areas use mainly desalinated water for their domestic water demands, and treated wastewater for irrigating green areas. Private water companies supply these hotels with their domestic water needs. There is normally a contractual agreement stating a minimum requirement that has to be supplied by the water company and that the hotel management has to pay for regardless of its actual consumption ("contracted-for water supply"). This paper describes a model to determine what value a hotel should choose for its contracted-for water supply in order to minimize its total annual water costs. An example from an arid coastal tourism-dominated city is presented: Sharm El Sheikh, Egypt.The managers of hotels with expected high occupancy rates (74% and above) can contract for more than 80%. On the other hand, hotels with expected lower occupancy rates (60% and less) can contract for less than 70% of the peak daily domestic water demand. With a green area ratio of 40 m(2)/room or less, an on-site wastewater treatment plant can satisfy the required irrigation demand for an occupancy rate as low as 42%. Increasing the ratio of green irrigated area to 100 m(2)/room does not affect the contracted-for water supply at occupancy rates above 72%; at lower occupancy rates, however, on-site treated wastewater is insufficient for irrigating the green areas. Increasing the green irrigated area to 120 m(2)/room increases the need for additional water, either from externally sourced treated wastewater or potable water. The cost of the former is much lower than the latter (0.58 versus 1.52 to 2.14 US$/m(3) in the case study area). PMID:19403967

  18. 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

  19. Tree ring imprints of long-term changes in climate in western Himalaya, Indi

    Indian Academy of Sciences (India)

    R R Yadav

    2009-11-01

    Tree-ring analyses from semi-arid to arid regions in western Himalaya show immense potential for developing millennia long climate records. Millennium and longer ring-width chronologies of Himalayan pencil juniper (Juniperus polycarpos), Himalayan pencil cedar (Cedrus deodara) and Chilgoza pine (Pinus gerardiana) have been developed from different sites in western Himalaya. Studies conducted so far on various conifer species indicate strong precipitation signatures in ring-width measurement series. The paucity of weather records from stations close to tree-ring sampling sites poses difficulty in calibrating tree-ring data against climate data especially precipitation for its strong spatial variability in mountain regions. However, for the existence of strong coherence in temperature, even in data from distant stations, more robust temperature reconstructions representing regional and hemispheric signatures have been developed. Tree-ring records from the region indicate multi-century warm and cool anomalies consistent with the Medieval Warm Period and Little Ice Age anomalies. Significant relationships noted between mean premonsoon temperature over the western Himalaya and ENSO features endorse utility of climate records from western Himalayan region in understanding long-term climate variability and attribution of anthropogenic impact.

  20. Emergence and extinction of Dipterocarpaceae in western India with reference to climate change: Fossil wood evidences

    Indian Academy of Sciences (India)

    Anumeha Shukla; R C Mehrotra; J S Guleria

    2013-10-01

    Climate has played a crucial role in assigning a different kind of topography to Rajasthan and Gujarat since the Cenozoic time. Evidently, three genera, namely, Dipterocarpus Gaert. f., Hopea Roxb. And Shorea Roxb. of the Dipterocarpaceae are described from the Neogene sediments of western India (Rajasthan and Gujarat). These taxa are marked by their complete absence in the region today. The presence of Dipterocarpaceae in western India has been noticed from the Early Eocene up to the Plio-Pleistocene in deep time. The family is usually a dominant component of the humid tropical and subtropical flora of the Indo-Malayan region and its discovery, along with earlier described fossils from western India indicates existence of ancient tropical rain forests in western India. A change in the climate affected warm and humid conditions occurring there during the Cenozoic resulting in arid to semi-arid climate at present which is responsible for the ultimate extinction of Dipterocarpaceae in the region. In addition, the palaeobiogeography of Dipterocarpaceae is reviewed.

  1. The World Revolution of Westernization.

    Science.gov (United States)

    Von Laue, Theodore H.

    1987-01-01

    Discusses the history of westernization from a global perspective. Analyzes the reasons for perceived Western "superiority," how these reasons contributed to the buildup of western power, and its attractiveness to non-Western cultures. Indicates the necessity for a trans-national, culturally non-specific view of history to meet this age of global…

  2. 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.

  3. Quantitative Prediction Study of Climate-sensitive Potassium with Hyperspectrum in Arid and Semi-arid Region of Northwestern China

    International Nuclear Information System (INIS)

    Soil potassium content in arid and semi-arid region can reflect the conditions of the paleoclimate and it can be inverted by soil spectra. The relationship between soil spectra and soil potassium content was discussed in this research. Based on four reflectance transformations, single-variance analysis and multi-variances inversion model were built to invert potassium content. The results of single-wavelength inversions were very significant except for the reflectance model. The multi-variances models were good and accurately (R2 (determination coefficient) >0.674 and RMSE (root-mean-square error) <0.09). Then, the sensitive wavelengths of the potassium were chosen by using the higher correlation coefficients. The results of this study showed that both methods have a great potential for predicting soil potassium content. The sensitive wavelengths of the potassium content were at 2200–2300 nm which could be illustrated by the potassium-bearing minerals spectral absorption features

  4. Refugia, colonization and diversification of an arid-adapted bird: coincident patterns between genetic data and ecological niche modelling.

    Science.gov (United States)

    Barrientos, Rafael; Kvist, Laura; Barbosa, Andrés; Valera, Francisco; Khoury, Fares; Varela, Sara; Moreno, Eulalia

    2014-02-01

    Phylogeographical studies are common in boreal and temperate species from the Palaearctic, but scarce in arid-adapted species. We used nuclear and mitochondrial markers to investigate phylogeography and to estimate chronology of colonization events of the trumpeter finch Bucanetes githagineus, an arid-adapted bird. We used 271 samples from 16 populations, most of which were fresh samples but including some museum specimens. Microsatellite data showed no clear grouping according to the sampling locations. Microsatellite and mitochondrial data showed the clearest differentiation between Maghreb and Canary Islands and between Maghreb and Western Sahara. Mitochondrial data suggest differentiation between different Maghreb populations and among Maghreb and Near East populations, between Iberian Peninsula and Canary Islands, as well as between Western Sahara and Maghreb. Our coalescence analyses indicate that the trumpeter finch colonized North Africa during the humid Marine Isotope Stage 5 (MIS5) period of the Sahara region 125 000 years ago. We constructed an ecological niche model (ENM) to estimate the geographical distribution of climatically suitable habitats for the trumpeter finch. We tested whether changes in the species range in relation to glacial-interglacial cycles could be responsible for observed patterns of genetic diversity and structure. Modelling results matched with those from genetic data as the species' potential range increases in interglacial scenarios (in the present climatic scenario and during MIS5) and decreases in glacial climates (during the last glacial maximum, LGM, 21 000 years ago). Our results suggest that the trumpeter finch responded to Pleistocene climatic changes by expanding and contracting its range. PMID:24215522

  5. Pacific Northwest Laboratory annual report for 1983 to the DOE Office of Energy Research. Part 2. Ecological sciences

    International Nuclear Information System (INIS)

    The 1983 annual report highlights research in five areas funded by the Ecological Sciences Division of the Office of Energy Research. The five areas include: western semi-arid ecosystems; marine sciences; mobilization fate and effects of chemical wastes; radionuclide fate and effects; and statistical and quantitative research. The work was accomplished under 19 individual projects. Individual projects are indexed separately

  6. Pacific Northwest Laboratory annual report for 1983 to the DOE Office of Energy Research. Part 2. Ecological sciences

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, B.E.

    1984-02-01

    The 1983 annual report highlights research in five areas funded by the Ecological Sciences Division of the Office of Energy Research. The five areas include: western semi-arid ecosystems; marine sciences; mobilization fate and effects of chemical wastes; radionuclide fate and effects; and statistical and quantitative research. The work was accomplished under 19 individual projects. Individual projects are indexed separately.

  7. Late Pleistocene-Holocene morphosedimentary architecture, Spiti River, arid higher Himalaya

    Science.gov (United States)

    Srivastava, Pradeep; Ray, Yogesh; Phartiyal, Binita; Sharma, Anupam

    2013-03-01

    The Spiti River drains the rain shadow zone of western Himalaya. In the present study, the fluvial sedimentary record of Spiti valley was studied to understand its responses to tectonics and climate. Geomorphic changes along the river enable to divide the river into two segments: (i) upper valley with a broad, braided channel where relict sedimentary sequences rise 15-50 m high from the riverbed and (ii) lower valley with a narrow, meandering channel that incises into bedrock, and here, the fluvio-lacustrine sediments reside on a bedrock bench located above the riverbed. The transition between these geomorphic segments lies along the river between Seko-Nasung and Lingti villages (within Tethyan Himalaya). Lithofacies analyses of the sedimentary sequences show six different lithofacies. These can be grouped into three facies associations, viz. (A) a glacial outwash; (B) sedimentation in a channel and in an accreting bar under braided conditions; and (C) formation of lake due to channel blockage by landslide activities. Seventeen optically stimulated luminescence ages derived from ten sections bracketed the phases of river valley aggradation between 14-8 and 50-30 ka. These aggradation phases witnessed mass wasting, channel damming and lake formation events. Our record, when compared with SW monsoon archives, suggests that the aggradation occurred during intensified monsoon phase of MIS 3/4 and that proceeded the Last Glacial Maxima. Thus, the study reports monsoon modulated valley aggradation in the NW arid Himalaya.

  8. Flood monitoring in a semi-arid environment using spatially high resolution radar and optical data.

    Science.gov (United States)

    Seiler, Ralf; Schmidt, Jana; Diallo, Ousmane; Csaplovics, Elmar

    2009-05-01

    The geographic term "Niger Inland Delta" stands for a vast plain of approximately 40,000 km(2), which is situated in the western Sahel (Republic of Mali). The Inland Delta is affected by yearly inundation through the variable water levels of the Niger-Bani river system. Due to a good availability of (surface) water, the ecosystem at the Niger Inland Delta serves as resting place stop-over for many migrating birds and other wildlife species as well as economic base for farmers and pastoral people. To foster the sustainable usage of its natural resources and to protect this natural heritage, the entire Niger Inland Delta became RAMSAR site in 2004. This paper aims to test to which extent texture analysis can improve the quality of flood monitoring in a semi-arid environment using spatially high resolution ASAR imaging mode data. We found the Gray Level Dependence Method (GLDM) was most suitable proceeding for our data. Several statistical parameters were calculated via co-occurrence matrices and were used to classify the images in different gradation of soil moisture classes. In a second step we used additional information from spatially high resolution optical data (ASTER) to improve the separability of open water areas from moisture/vegetated areas. PMID:18554774

  9. Fishery Resources in Arid Zone Mangroves in Gulf of Kachchh, Gujarat, Northwest Coast of India

    Institute of Scientific and Technical Information of China (English)

    A. Saravanakumar; M. Rajkumar; J. Sesh Serebiah; G. A. Thivakaran

    2009-01-01

    The finfish and shellfish resources were assessed quantitatively and qualitatively in regard to their abundance in creek waters at three sites within a period of two years, from January 1999 to December 2000, in the western mangrove areas of Kachchh.The catch rate varied from 0.69 to 6.99 kg h-1. It was low during monsoon (July to October), which could be due to the freshwater-flow-induced salinity reduction in all the sites. Among 38 species recorded, 5 were shellfish and 33 were finfish. The spawning period of fishes was found to be during summer and early monsoon period (May to August). Surface water temperatures varied from 17 ℃ to 37 ℃. Salinity values varied from 34 to 44 and the pH ranged between 7 and 8.9. Variation in dissolved oxygen content was from 3.42 to 5.85 mLL-1. The high fishery densities in these semi arid mangrove creek areas were recorded during monsoon and early winter season.

  10. Rings dominate western Gulf

    Science.gov (United States)

    Vidal L., Francisco V.; Vidal L., Victor M. V.; Molero, José María Pérez

    Surface and deep circulation of the central and western Gulf of Mexico is controlled by interactions of rings of water pinched from the gulf's Loop Current. The discovery was made by Mexican oceanographers who are preparing a full-color, 8-volume oceanographic atlas of the gulf.Anticyclonic warm-core rings pinch off the Loop Current at a rate of about one to two per year, the scientists of the Grupo de Estudios Oceanográficos of the Instituto de Investigaciones Eléctricas (GEO-IIE) found. The rings migrate west until they collide with the continental shelf break of the western gulf, almost always between 22° and 23°N latitude. On their westward travel they transfer angular momentum and vorticity to the surrounding water, generating cyclonic circulations and vortex pairs that completely dominate the entire surface and deep circulation of the central and western gulf.

  11. 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.

  12. Local Population Structure and Patterns of Western Hemisphere Dispersal for Coccidioides spp., the Fungal Cause of Valley Fever

    OpenAIRE

    Engelthaler, David M.; Roe, Chandler C.; Hepp, Crystal M.; Teixeira, Marcus; Driebe, Elizabeth M; Schupp, James M.; Gade, Lalitha; Waddell, Victor; Komatsu, Kenneth; Arathoon, Eduardo; Logemann, Heidi; Thompson, George R; Chiller, Tom; Barker, Bridget; Keim, Paul

    2016-01-01

    ABSTRACT Coccidioidomycosis (or valley fever) is a fungal disease with high morbidity and mortality that affects tens of thousands of people each year. This infection is caused by two sibling species, Coccidioides immitis and C. posadasii, which are endemic to specific arid locales throughout the Western Hemisphere, particularly the desert southwest of the United States. Recent epidemiological and population genetic data suggest that the geographic range of coccidioidomycosis is expanding, as...

  13. Performance and effects of land cover type on synthetic surface reflectance data and NDVI estimates for assessment and monitoring of semi-arid rangeland

    Science.gov (United States)

    Olexa, Edward M.; Lawrence, Rick L.

    2014-08-01

    Federal land management agencies provide stewardship over much of the rangelands in the arid and semi-arid western United States, but they often lack data of the proper spatiotemporal resolution and extent needed to assess range conditions and monitor trends. Recent advances in the blending of complementary, remotely sensed data could provide public lands managers with the needed information. We applied the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) to five Landsat TM and concurrent Terra MODIS scenes, and used pixel-based regression and difference image analyses to evaluate the quality of synthetic reflectance and NDVI products associated with semi-arid rangeland. Predicted red reflectance data consistently demonstrated higher accuracy, less bias, and stronger correlation with observed data than did analogous near-infrared (NIR) data. The accuracy of both bands tended to decline as the lag between base and prediction dates increased; however, mean absolute errors (MAE) were typically ≤10%. The quality of area-wide NDVI estimates was less consistent than either spectral band, although the MAE of estimates predicted using early season base pairs were ≤10% throughout the growing season. Correlation between known and predicted NDVI values and agreement with the 1:1 regression line tended to decline as the prediction lag increased. Further analyses of NDVI predictions, based on a 22 June base pair and stratified by land cover/land use (LCLU), revealed accurate estimates through the growing season; however, inter-class performance varied. This work demonstrates the successful application of the STARFM algorithm to semi-arid rangeland; however, we encourage evaluation of STARFM's performance on a per product basis, stratified by LCLU, with attention given to the influence of base pair selection and the impact of the time lag.

  14. Feeding corn during the last 12 days of gestation improved colostrum production and neonatal activity in goats grazing subtropical semi-arid rangeland.

    Science.gov (United States)

    Ramírez-Vera, S; Terrazas, A; Delgadillo, J A; Serafín, N; Flores, J A; Elizundia, J M; Hernández, H

    2012-07-01

    The objectives were to investigate if partial substitution of a grazing diet with a supplemental high-starch feed during the last 12 d of gestation improved colostrum yield and neonatal activity in goat does grazing semi-arid rangeland. For the first objective, 25 pregnant does were randomly assigned to 1 of 2 treatments: 1) grazing only (control; n = 11), and 2) grazing plus 0.6 kg/d of supplemental corn (as fed), a high starch feed, during the last 12 ± 1.0 d before parturition (SC; n = 14). Colostrum was collected at parturition and again at 1, 3, 6, and 10 h postpartum for yield and composition. In all goats, blood concentrations of glucose and plasma progesterone were determined. Total colostrum yield/10 h was greater (P = 0.002) in the SC does (1,102 ± 144 g) than in control does (405 ± 50 g). From 6 to 10 h postpartum, contents of colostrum protein and solids not fat were less (P ≤ 0.012) whereas lactose contents were greater (P = 0.035) in the SC does than in control does. Concentration of glucose in the blood at parturition was greater (P = 0.037) in the SC does (160 ± 13 mg/dL) than in control does (115 ± 12 mg/dL). A significant decrease (P = 0.001) in plasma progesterone concentrations occurred 1 d before parturition in control does, whereas the decrease (P = 0.008) occurred 3 d before parturition in SC does. For the second objective, 20 does (10 per group) and their single kids were randomly assigned to the same treatments as above for evaluation of dietary treatment on neonatal activity. Kid activity was assessed using videos recorded during the first 90 min after birth. Frequency of low-pitched bleats was greater (P kids of SC does than in kids of controls. Frequencies and durations of teat seeking from 30 to 90 min after birth and of suckling activity were greater (P ≤ 0.015) in kids of SC does than in kids of controls. Duration of parturition was longer (P = 0.001) in control does (58 ± 10.2 min) than in SC does (21 ± 2.8 min). Finally

  15. 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...

  16. 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...

  17. 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

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. Seeking common ground: Western governors and the WIPP transport campaign

    International Nuclear Information System (INIS)

    Nine Western States have engaged the US DOE to prepare for shipments of nuclear weapons waste. These are shipments of transuranic (TRU) wastes from nuclear weapons production facilities to the Waste Isolation Pilot Plant (WIPP). Western governors convinced the US Secretary of Energy that federal, state, and local governments must work together for safety and public acceptance of these shipments. The Secretary agreed to fund state preparedness. Through the Western Governors Association, seven states and USDOE are developing complementary safety programs. This project will identify lessons learned for eventual shipments of high level radioactive waste

  4. China's Western Priority

    Institute of Scientific and Technical Information of China (English)

    YU SHUJUN

    2010-01-01

    @@ "Western Development" has become a buzzword in China over the past decade. It has appeared almost everywhere: in government docu-ments, media reports and even ordinary people's conversations. It has become a national campaign in the new century, with a wide variety of resources--human, financial and material-- flowing to the westem part of the country.

  5. 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

  6. 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

  7. Sustainable Small-Scale Agriculture in Semi-Arid Environments

    OpenAIRE

    Scott Ingram; Margaret Nelson; Katherine A. Spielmann; Peeples, Matthew A.

    2011-01-01

    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. W...

  8. New Discovery of Coral Rubbings in the North-Western Gulf of Kachchh, Gujarat, Western India-GIS Based Evaluation

    Institute of Scientific and Technical Information of China (English)

    J. Sesh Serebiah; M. Rajkumar; SUN Jun; B. A. Venmathi Maran; A. Saravanakumar; G. A. Thivakaran

    2011-01-01

    The Gulf of Kachchh in western India, with its arid climate, large semi-diurnal tidal amplitudes, negative water balance and near-pristine water quality, is being extensively developed as oil importing bases for economic reasons in connection with its proximity to the oil exporting countries of the Middle East. Besides, new coral robbings were sighted in Jakhau, north-western Gulf of Kachchh. Dredging in Mandvi of the north Gulf covering 3.5 km2 revealed a similar assortment of live corals with their associated flora and fauna. These pioneering observations demonstrate that there exist live corals of young polyps-colony of Favia sp. belonging to the family Faviidae in the north-western Gulf of Kachchh. The environmental parameters there were carefully recorded as: surface water temperature (℃) varying from 29 to 31.8, salinity (ppt), pH, dissolved oxygen (mgL-l)and total suspended solids (mgL-1) in the ranges of 37- 43.5, 7.7- 8.45, 5.4 - 6.8 and 11- 31, respectively.

  9. 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

  10. Environmental Effects of Irrigation in Arid and Semi-Arid Regions Efectos Ambientales del Riego en Regiones Áridas y Semi-Áridas en América Latina

    OpenAIRE

    Alicia Fernández Cirelli; José Luis Arumí; Diego Rivera; Peter  W Boochs

    2009-01-01

    This article reviews the state of the art with respect to the environmental effects of irrigated agriculture on water and soil quality in arid and semi-arid regions on a field scale. Information is scarce and fragmentary. Examples in selected areas of other arid and semi-arid regions in the world clearly show the importance of studying the environmental impact of irrigation practices on water and soil quality. Studies mainly refer to waterlogging and salinization. As regards agrochemicals, fe...

  11. Internal globalization of Western Balkan

    Directory of Open Access Journals (Sweden)

    Vukotić Veselin

    2006-01-01

    Full Text Available What are potential and real effects of the globalization process on the economic connection between Western Balkan countries? What is the crucial change in relations between Western Balkan countries and its economies inexorably brought by globalization? What are the elements of political economy of Western Balkan globalization? What are reflections of the conflict between political and economic areas of Western Balkan? These are some of the issues discuses in this paper.

  12. Internal Globalization of Western Balkan

    OpenAIRE

    Vukotić Veselin

    2006-01-01

    What are potential and real effects of the globalization process on the economic connection between Western Balkan countries? What is the crucial change in relations between Western Balkan countries and its economies inexorably brought by globalization? What are the elements of political economy of Western Balkan globalization? What are reflections of the conflict between political and economic areas of Western Balkan? These are some of the issues discuses in this paper.

  13. 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

  14. 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

  15. 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

  16. The Potential Contribution of Subsurface Drip Irrigation to Water-Saving Agriculture in the Western USA

    Institute of Scientific and Technical Information of China (English)

    T L Thompson; PANG Huan-cheng; LI Yu-yi

    2009-01-01

    Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation (SDI) provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics (i.e., paying for the SDI system), including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.

  17. Estimation of vegetation fraction in arid areas using ALOS imagery

    Science.gov (United States)

    Matkan, A. A.; Darvishzadeh, R.; Hosseiniasl, A.; Ebrahimi, M.

    2010-10-01

    Fraction of vegetation (Fv) plays an important role in ecosystems. Estimation of Fv is essential for drought monitoring, natural resources studies, estimation of soil erosion volume etc. The aim of this study is to estimate Fv in an arid area in Iran using ALOS Imagery (June 2008). In order to find the best index for estimation of Fv, Seventeen vegetation indices (ARVI, DVI, EVI, GEMI, IPVI, MSAVI1, MSAVI2, NDVI, PVI, SAVI, SARVI, SARVI2, SR, TSAVI, WDVI) were used. The canopy cover percentage of 52 sample plots (50m by 50m) was measured in the field in June 2009. Regression models were used to assess the relationships between the field data and the calculated Fv. The 52 sample plots were randomly divided two times to 30 calibrations and 22 validations, and to 35 and 17 samples. Results revealed that selecting the calibration and validation data randomly leads to different results. Therefore, cross-validation method was used to reduce random division effect. Results indicated that, among all indices, vegetation indices such as MSAVI1, PVI, WDVI and TSAVI which are based on soil line have higher R2 and lower RMSE (R2 > 0.63, RMSE ~ 3%). The results confirm the dominant effect of soil reflectance in arid areas.

  18. 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.

  19. 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.

  20. Uranium isotopes in carbonate aquifers of arid region setting

    International Nuclear Information System (INIS)

    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 238U at 3-39 ng L-1 (average: 18 ng L-1) and 429-5,293 ng L-1 (average: 2,508 ng L-1) respectively. These uranium concentrations are below the higher permissible WHO limit for drinking water and also comparable to averages found in groundwater from similar aquifers in Florida and Tunisia. Negative correlation between rainfall and uranium concentrations suggests that in lithologically comparable aquifers, climate may influence the concentration of uranium in subtropical to arid regions. (author)

  1. 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.

  2. 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.

  3. 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.

  4. An Evaluation of Unsaturated Flow Models in an Arid Climate

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. Physicochemical and biochemical properties of honeys from arid regions.

    Science.gov (United States)

    Habib, Hosam M; Al Meqbali, Fatima T; Kamal, Hina; Souka, Usama D; Ibrahim, Wissam H

    2014-06-15

    This study was conducted to evaluate the quality of 11 honeys from arid regions for first time, and compare it with 5 different honeys from non-arid regions. Mean values obtained for physicochemical parameters were: pH 4.76 ± 0.55; 17.32 ± 1.8% moisture; 80.95 ± 1.60 °Brix sugar; 69.05 ± 4.41% total sugar; 413.81 ± 178.48 μS cm(-1) electrical conductivity; 17.58 ± 7.68 meq/kg free acidity; 11.05 ± 3.18 meq/kg lactonic acidity; 28.63 ± 9.6 meq/kg total acidity; 12.66 ± 20.39 mg/kg HMF; 0.58 ± 0.03 water activity; and 0.98 ± 0.62 colour intensity. Potassium was the major mineral (1760.54 ± 685.24 mg/kg). All the samples showed considerable significant variations with reference to their physicochemical and biochemical properties, moreover, the total free amino acids and total carotenoids were 61.13 ± 63.16 mg/100g and 4.07 ± 10.05 μg/100g respectively. Acrylamide was detected only in one sample at 2.39 ± 0.22 μg/kg. PMID:24491697

  7. 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.

  8. Isotope hydrology applied to evaluation of groundwater in arid areas

    International Nuclear Information System (INIS)

    Capture of underground water in arid or semi-arid areas in developing countries is essential to safeguarding life. In order to realize in time, or to prevent, endangerment of exploitable groundwater resources due to pollution or excess exploitation, isotope hydrology offers low-cost methods that are applied along with other methods. Their results contribute to determine the origin, mixing, residence time (or age), and pollution of endangered groundwater resources. The research report in hand uses the results of hydrochemical analyses and isotope hydrological data from hydrogeological studies made over some years by the Bundesanstalt fuer Geowissenschaften und Rohstoffe in six selected countries: Jordan, Cyprus, Brazil, Sudan, Djibouti, Senegal. It also uses data of recent analyses of the years 1985 and 1986. Data evaluation is done applying modern, qualitative and quantitative methods of interpretation. The available long-term series of isotopic data are scanned for any early information on water quality deterioration that is not otherwise detected. The information thus obtained is a prerequisite of urgently needed measures for protecting the groundwater reserves. (orig./HP)

  9. WATER MANAGEMENT AND EXTERNALITIES IN TROPICAL ARID- AND SEMI-ARID AGRICULTURE: AN ECONOMIC APPROACH BASED ON EXAMPLES OF NITRATE LOSSES AND SALINIZATION

    OpenAIRE

    Baird, Kathrine E.

    1989-01-01

    This paper summarized the theory of welfare economics and natural resource allocation, and illustrated how application of this theory can lead to Pareto improvements in the design of irrigation systems in tropical arid- and semi-arid agricultural systems. Drawing on the two examples of nitrate losses and salinization, the paper concludes that economic analysis can help design policies to conserve natural resource stocks, but that such analysis is limited by insufficient data, methodological d...

  10. 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...

  11. A Two-source Energy Balance Model for estimating evapotranspiration over an olive orchard in a semi-arid region of Morocco

    Science.gov (United States)

    Ezzahar, Jamal; Chehbouni, Abdelghani; Er-Raki, Salah; Aouade, Ghizlane; Khabba, Said; Merlin, Olivier; Boulet, Gilles; Jarlan, Lionel

    2016-04-01

    In arid and semi-arid regions, about 85% of the available water is used for irrigated agriculture, and therefore a sound and efficient irrigation practice is an important step towards achieving sustainable management of water resources in these regions. In this regard, a better understanding of the water balance is essential for exploring water-saving techniques. One of the most important components of the water balance in semi-arid areas is the evapotranspiration (ET). Therefore, a precise estimation evapotranspiration is of crucial importance for agricultural water management. In this work, a two source energy balance model (TSEB) is used to estimate ET over an irrigated olive orchard located near located near to the Marrakech city (Centre of Morocco). In addition to its simplicity, TSEB does not require a large number of input parameters that are not readily available. Evapotranspiration and micrometeorological parameters were continuously measured during the year 2003 in order to evaluate the performance of TSEB estimates. The comparison between daily estimated and measured evapotranspiration yielded a good agreement although the complexity of the study surface with a correlation coefficient of 0.78 and a root mean square of 61.9wm-².

  12. 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)

  13. 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)

  14. 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.

  15. The limitations of seedling growth and drought tolerance to novel soil substrates in arid systems: Implications for restoration success

    Science.gov (United States)

    Bateman, Amber; Lewandrowski, Wolfgang; Stevens, Jason; Muñoz-Rojas, Miriam

    2016-04-01

    Introduction With the limited knowledge available regarding the impact of drought on seedling growth, an understanding of seedling tolerance to arid conditions is crucial for restoration success (James et al., 2013; Muñoz-Rojas et al., 2014). However, restoration in semi-arid areas faces the challenge of re-establishing plant communities on altered soil substrates (Muñoz-Rojas et al., 2015). These substrates are a result of anthropogenic disturbances such as mining which have altered the plant-soil-water dynamics of the ecosystem (Machado et al., 2013). The aim of this study was to assess the impact of mining on the plant-soil-water dynamics of an arid ecosystem of Western Australia (Pilbara region, North Western Australia) and the implications these altered relationships have on seedling growth and their responses to drought. Methods Drought responses of native plant species were assessed through a series of glasshouse experiments. Firstly, 21 species dominant to the Pilbara region were subjected to drought in a topsoil growth media to assess variation in responses (leaf water potential at the time of stomatal closure) across species and identify traits associated with drought tolerance. Secondly, four species ranging in their drought tolerance identified previously, were grown to two leaf stages (second and fourth leaf stage) in three mining substrates (topsoil, a topsoil and waste mix and waste) to assess seedling drought responses to various potential restoration substrates and how that varied with plant development stage. Results and discussion Four morphological traits were found to be significantly associated with drought indicators (leaf mass ratio, stem area, stem length, stem weight), however, these were weak correlations. Waste substrate and its addition to topsoil reduced plant total biomass but did not alter species responses to drought. However, the soil physical properties of the waste reduced water retention and water availability for plant uptake

  16. Precipitation pulses and carbon fluxes in semiarid and arid ecosystems.

    Science.gov (United States)

    Huxman, Travis E; Snyder, Keirith A; Tissue, David; Leffler, A Joshua; Ogle, Kiona; Pockman, William T; Sandquist, Darren R; Potts, Daniel L; Schwinning, Susan

    2004-10-01

    In the arid and semiarid regions of North America, discrete precipitation pulses are important triggers for biological activity. The timing and magnitude of these pulses may differentially affect the activity of plants and microbes, combining to influence the C balance of desert ecosystems. Here, we evaluate how a "pulse" of water influences physiological activity in plants, soils and ecosystems, and how characteristics, such as precipitation pulse size and frequency are important controllers of biological and physical processes in arid land ecosystems. We show that pulse size regulates C balance by determining the temporal duration of activity for different components of the biota. Microbial respiration responds to very small events, but the relationship between pulse size and duration of activity likely saturates at moderate event sizes. Photosynthetic activity of vascular plants generally increases following relatively larger pulses or a series of small pulses. In this case, the duration of physiological activity is an increasing function of pulse size up to events that are infrequent in these hydroclimatological regions. This differential responsiveness of photosynthesis and respiration results in arid ecosystems acting as immediate C sources to the atmosphere following rainfall, with subsequent periods of C accumulation should pulse size be sufficient to initiate vascular plant activity. Using the average pulse size distributions in the North American deserts, a simple modeling exercise shows that net ecosystem exchange of CO2 is sensitive to changes in the event size distribution representative of wet and dry years. An important regulator of the pulse response is initial soil and canopy conditions and the physical structuring of bare soil and beneath canopy patches on the landscape. Initial condition influences responses to pulses of varying magnitude, while bare soil/beneath canopy patches interact to introduce nonlinearity in the relationship between pulse

  17. 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

  18. Understanding environmental drivers in the regulation of soil respiration dynamics after fire in semi-arid ecosystems

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Lewandrowski, Wolfgang; Erickson, Todd E.; Dixon, Kingsley W.; Merritt, David J.

    2016-04-01

    Keywords: Pilbara, soil CO2 efflux, soil C, soil moisture, soil temperature Introduction Soil respiration (Rs) has become a major research focus given the increase in atmospheric CO2 emissions and the large contribution of these CO2 fluxes from soils (Van Groenigen et al., 2014). In addition to its importance in the global C cycle, Rs is a fundamental indicator of soil health and quality that reflects the level of microbial activity and provides an indication of the ability of soils to support plant growth (Oyonarte et al., 2012; Munoz-Rojas et al., 2015). Wildfires can have a significant impact on Rs rates, with the scale of the impact depending on environmental factors such as temperature and moisture, and organic C content in the soil. Vegetation cover can have a significant effect on regulating organic C contents; and while advances are made into understanding the effects of fire on organic C contents and CO2 fluxes (Granged et al., 2011; Willaarts et al., 2015; Muñoz-Rojas et al., 2016), there is limited knowledge of the variability of Rs across ecosystem types, vegetation communities, and responses to fire. In this research we aimed to assess the impacts of a wildfire on the soil CO2 fluxes and soil respiration in a semi-arid ecosystem of Western Australia (Pilbara biogeographical region), and to understand the main environmental drivers controlling these fluxes in different vegetation types. The study has application for other arid and semi-arid regions of the world. Methods The study area was selected following a wildfire that affected 25 ha in February 2014. Twelve plots were established in the burnt site (B) within a 400 m2 area, and 12 plots in an adjacent unburnt control site. At each site, three plots were installed below the canopy of each of the most representative vegetation types of the areas: Eucalyptus trees, Acacia shrubs and Triodia grasses, and three on bare soil. Soil sampling and measurement of soil CO2 efflux, temperature and moisture were

  19. Cheatgrass is favored by warming but not CO2 enrichment in a semi-arid grassland.

    Science.gov (United States)

    Blumenthal, Dana M; Kray, Julie A; Ortmans, William; Ziska, Lewis H; Pendall, Elise

    2016-09-01

    Elevated CO2 and warming may alter terrestrial ecosystems by promoting invasive plants with strong community and ecosystem impacts. Invasive plant responses to elevated CO2 and warming are difficult to predict, however, because of the many mechanisms involved, including modification of phenology, physiology, and cycling of nitrogen and water. Understanding the relative and interactive importance of these processes requires multifactor experiments under realistic field conditions. Here, we test how free-air CO2 enrichment (to 600 ppmv) and infrared warming (+1.5 °C day/3 °C night) influence a functionally and phenologically distinct invasive plant in semi-arid mixed-grass prairie. Bromus tectorum (cheatgrass), a fast-growing Eurasian winter annual grass, increases fire frequency and reduces biological diversity across millions of hectares in western North America. Across 2 years, we found that warming more than tripled B. tectorum biomass and seed production, due to a combination of increased recruitment and increased growth. These results were observed with and without competition from native species, under wet and dry conditions (corresponding with tenfold differences in B. tectorum biomass), and despite the fact that warming reduced soil water. In contrast, elevated CO2 had little effect on B. tectorum invasion or soil water, while reducing soil and plant nitrogen (N). We conclude that (1) warming may expand B. tectorum's phenological niche, allowing it to more successfully colonize the extensive, invasion-resistant northern mixed-grass prairie, and (2) in ecosystems where elevated CO2 decreases N availability, CO2 may have limited effects on B. tectorum and other nitrophilic invasive species. PMID:27090757

  20. Trends of precipitation extreme indices over a subtropical semi-arid area using PERSIANN-CDR

    Science.gov (United States)

    Katiraie-Boroujerdy, Pari-Sima; Ashouri, Hamed; Hsu, Kuo-lin; Sorooshian, Soroosh

    2016-08-01

    In this study, satellite-based daily precipitation estimation data from precipitation estimation from remotely sensed information using artificial neural networks (PERSIANN)-climate data record (CDR) are being evaluated in Iran. This dataset (0.25°, daily), which covers over three decades of continuous observation beginning in 1983, is evaluated using rain-gauge data for the period of 1998-2007. In addition to categorical statistics and mean annual amount and number of rainy days, ten standard extreme indices were calculated to observe the behavior of daily extremes. The results show that PERSIANN-CDR exhibits reasonable performance associated with the probability of detection and false-alarm ratio, but it overestimates precipitation in the area. Although PERSIANN-CDR mostly underestimates extreme indices, it shows relatively high correlations (between 0.6316-0.7797) for intensity indices. PERSIANN-CDR data are also used to calculate the trend in annual amounts of precipitation, the number of rainy days, and precipitation extremes over Iran covering the period of 1983-2012. Our analysis shows that, although annual precipitation decreased in the western and eastern regions of Iran, the annual number of rainy days increased in the northern and northwestern areas. Statistically significant negative trends are identified in the 90th percentile daily precipitation, as well as the mean daily precipitation from wet days in the northern part of the study area. The positive trends of the maximum annual number of consecutive dry days in the eastern regions indicate that the dry periods became longer in these arid areas.

  1. 78 FR 61621 - Endangered and Threatened Wildlife and Plants; Proposed Threatened Status for the Western...

    Science.gov (United States)

    2013-10-03

    ... higher egg water loss in the hotter, drier conditions of western North America (Hamilton and Hamilton... yellow-billed cuckoos in western North America, and those on the Pecos River in Texas and eastern Mexico... recognition of DPSs (61 FR 4721; February 7, 1996). What does this rule consist of and what is the...

  2. Why Chinese People Play Western Classical Music: Transcultural Roots of Music Philosophy

    Science.gov (United States)

    Huang, Hao

    2012-01-01

    This paper addresses the complex relationship between Confucian values and music education in East Asia, particularly its history in China. How does one account for the present "cultural fever" of Western classical music that has infected more than 100 million Chinese practitioners? It is proposed that Western classical music finds transcultural…

  3. 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)

  4. 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.

  5. Dynamic modeling of vegetation change in arid lands

    Science.gov (United States)

    Robinson, V. B.; Coiner, J. C.; Barringer, T. H.

    1982-01-01

    A general framework for a digital desertification monitoring system (DDMS) for assessing the worldwide desertification growth rate is presented. The system relies on the development of Landsat derived indicators to identify local processes signalling the growth of arid regions. A study area consisting of the eastern edge of the Niger River delta in Mali was used to characterize three indicators in terms of the covariance of the multispectral scanner (MSS) bands 2 and 4, the correlation of the two bands, and the percent variance expressed by the first eigenvalue. The scenes are imaged multitemporallly in a 400 x 400 pixel array to detect vegetation cover changes. Criteria were defined which characterized the decrease or increase of vegetation. It was determined that the correlation coefficients are the best indicators, and are easily computed.

  6. 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

  7. 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.)

  8. Diversity and activity of denitrifiers of Chilean arid soil ecosystems

    Directory of Open Access Journals (Sweden)

    GescheBraker

    2012-04-01

    Full Text Available The Chilean sclerophyllous matorral is a Mediterranean semiarid ecosystem affected by erosion, with low soil fertility and limited by nitrogen. However, limitation of resources is even more severe for desert soils such as from the Atacama Desert, one of the most extreme arid deserts on Earth. Topsoil organic matter, nitrogen and moisture content were significantly higher in the semiarid soil compared to the desert soil. Although the most significant loss of biologically preferred nitrogen from terrestrial ecosystems occurs via denitrification, virtually nothing is known on the activity and composition of denitrifier communities thriving in arid soils. In this study, we explored denitrifier communities from two soils with profoundly distinct edaphic factors. While denitrification activity in the desert soil was below detection limit, the semiarid soil sustained denitrification activity. To elucidate the genetic potential of the soils to sustain denitrification processes we performed community analysis of denitrifiers based on nitrite reductase (nirK and nirS genes as functional marker genes for this physiological group. Presence of nirK-type denitrifiers in both soils was demonstrated but failure to amplify nirS from the desert soil suggests very low abundance of nirS-type denitrifiers shedding light on the lack of denitrification activity. Phylogenetic analysis showed a very low diversity of nirK with only three distinct genotypes in the desert soil which conditions presumably exert a high selection pressure. While nirK diversity was also limited to only few, albeit distinct genotypes, the semiarid matorral soil showed a surprisingly broad genetic variability of the nirS gene. The Chilean matorral is a shrub land plant community which form vegetational patches stabilizing the soil and increasing its nitrogen and carbon content. These islands of fertility may sustain the development and activity of the overall microbial community and of

  9. 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.

  10. Isotopic evidence of the origin of groundwater in arid zones

    International Nuclear Information System (INIS)

    The contribution of different pathways of recharge to the groundwater in the Negev desert, the southern arid part of Israel, is examined by means of isotope and chemical signatures which are imprinted on the waters. In regions covered by sand dunes, with no perennial vegetation cover, it was found that evaporation amounts to about 30%, while 70% of the rain water infiltrates into the subsurface. In dune areas covered by deep-rooted vegetation, all water flowing into the subsurface may be transpired by the vegetation. In limestone areas, recharge to groundwater is of the order of 2% and is mainly through gravel-filled river beds by flood water. The water from springs and wells in the Eocene limestone terrain conserves the mean isotopic composition of rainfall, with a tendency for enrichment in the heavy isotopes. The salinity of the groundwater is a function of rock dissolution rather than of evaporation. In chalk-built terrains the water flows in solution channels developed along joints in the vicinity of river beds. The tritium content of the water points towards a 'piston-action' model of recharge by floods. A preliminary study of the isotope salinity relations in the runoff from a small watershed has shown that rains which do not pass a certain threshold (2 mm) evaporate totally. Evaporation from surface flows produced by stronger rains is small. Salinity is increased by a factor of two as a result of flushing of salts left behind by previous, totally evaporated rains. All data lead to the conclusion that in arid regions the total quantity of water in local basins is limited. However, base-level basins, such as inter-mountain basins, rift valleys, etc., form a sink into which relatively small quantities from local watersheds flow which may accumulate to substantial quantities that could be used for regional development projects. The Arava rift valley is discussed as a case study. (author)

  11. The Last Western Flyer: The Western Auto Century

    OpenAIRE

    Marchman, James

    2004-01-01

    A treasure trove of pictures and history, The Last Western Flyer chronicles one of the most successful small town franchise operations in 20th Century America, Western Auto. It grew from humble beginnings as a penny mailer sent from the kitchen of a Kansas City home to over 5,000 retail outlets under its Circle Arrow signs. Western Auto brought everything from tires, spark plugs, socks, vitamin pills, fishing lures, radios and more, including its famous Western Flyer bikes to America’s major ...

  12. Monitoring variations of inland lakes in the arid region of Central Asia

    Institute of Scientific and Technical Information of China (English)

    Jie BAI; Xi CHEN; Liao YANG; Hui FANG

    2012-01-01

    Inland lakes are the major surface water resource in the arid regions of Central Asia.Therefore,the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activities,and have often been the focus of ecological and environmental research.This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period.The water body was extracted from MSS images from the mid-1970s,TM images from the early 1990s,ETM + images in the late 1990s,and TM images in 2007.The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area,from 91402.06 km2 in 1975 to 46049.23 km2 in 2007.As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part,the shrinking trend of lake area was more significant in the west than in the east.There was a varied reduction of closed lakes in flat regions.The most substantial decrease was in the surface area of closed lakes in flat regions.Most significantly,the area of the Aral Sea was reduced by 75.7% from its original area in 1975.The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007.The area change in opened lakes with outlets was notably different from the other two types.The area of Zaysan had increased sharply by 5.85%,and that of Bosten had decreased by 9.1%.Sasykkol had hardly any changes in this period.Due to global climate warming,vapor transfer to the south via westerly winds had been blocked,resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan,Uzbekistan,and Kazakhstan between 1970 and 2000.The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of river runoff.Consequently,the area of inland lakes in Central Asia shrank over the past 32 years.

  13. 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.

  14. 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

  15. 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.

  16. Carbon tetrachloride contamination, 200 West Area, Hanford Site: Arid Site Integrated Demonstration for remediation of volatile organic compounds

    International Nuclear Information System (INIS)

    The Arid State Integrated Demonstration is a US Department of Energy (DOE) program targeted at the acquisition, development, demonstration, and deployment of technologies for evaluation and cleanup of volatile organic and associated contaminants in soils and ground waters. Several DOE laboratories, universities, and industry will participate in the program. Candidate technologies will be demonstrated in the areas of site characterization; performance prediction, monitoring, and evaluations; contaminant extraction and ex situ treatment; in situ remediations; and site closure and monitoring. The performance of these demonstrated technologies will be compared to baseline technologies and documented to promote the transfer of new technologies to industry for use at DOE facilities. The initial host site is the Hanford Site's 200 West Area. The location of the demonstration contains primarily carbon tetrachloride (CCl4), chloroform, and a variety of associated mixed waste contaminants. Chemical processes used to recover and purify plutonium at Hanford's plutonium finishing plant (Z Plant) resulted in the production of actinide-bearing waste liquid. Both aqueous and organic liquid wastes were generated, and were routinely discharged to subsurface disposal facilities. The primary radionuclide in the waste streams was plutonium, and the primary organic was CCl4. This paper contains brief descriptions of the principal CCl4 waste disposal facilities in Hanford's 200 West Area, associated hydrogeology, existing information on the extent of soil and ground-water contamination, and a conceptual outline of suspected subsurface CCl4 distributions

  17. Western Parenting: A Personal Perspective

    Institute of Scientific and Technical Information of China (English)

    Paul Ward

    2011-01-01

    Bonding: Western fathers are keen to take an equal role in parenting. They recognise their responsibility as a new dad, and are committed early to sharing every family task with the mother. It is common to see a proud western father walking outside, on their own, with their tiny baby. Western dad's know that this time is special, and the mother needs to relax and feel confident to trust the dad with the baby.

  18. Modeling a Sustainable Salt Tolerant Grass-Livestock Production System under Saline Conditions in the Western San Joaquin Valley of California

    OpenAIRE

    Stephen R. Kaffka; John Maas; James D. Oster; Máximo F. Alonso; Dennis L. Corwin

    2013-01-01

    Salinity and trace mineral accumulation threaten the sustainability of crop production in many semi-arid parts of the world, including California’s western San Joaquin Valley (WSJV). We used data from a multi-year field-scale trial in Kings County and related container trials to simulate a forage-grazing system under saline conditions. The model uses rainfall and irrigation water amounts, irrigation water quality, soil, plant, and atmospheric variables to predict Bermuda grass ( Cynodon dac...

  19. Western Canada uranium perspective

    International Nuclear Information System (INIS)

    The current situation in the exploration for uranium in British Columbia, the Yukon, the Northwest Territories, and Saskatchewan is reviewed. A moratorium on exploration has been in effect in British Columbia since 1980; it is due to expire in 1987. Only the Blizzard deposit appears to have any economic potential. The Lone Gull discovery in the Thelon Basin of the Northwest Territories has proven reserves of more than 35 million pounds U3O8 grading 0.4%. Potentially prospective areas of the northern Thelon Basin lie within a game sanctuary and cannot be explored. Exploration activity in Saskatchewan continues to decline from the peak in 1980. Three major deposits - Cluff Lake, Rabbit Lake and Key Lake - are in production. By 1985 Saskatchewan will produce 58% of Canada's uranium, and over 13% of the western world's output. (L.L.) (3 figs, 2 tabs.)

  20. Ecotoxicology of organisms adapted to life in temporary freshwater ponds in arid and semi-arid regions.

    Science.gov (United States)

    Lahr, J

    1997-01-01

    Hot arid and semi-arid zones are characterized by an abundance of temporary ponds. Most of these depend on rain for their existence. These habitats are distinguished by fluctuating and unpredictable changes in their hydrological regime and of physical and chemical conditions.They contain a uniquely-adapted fauna that copes in different ways with changing and often extreme temperatures, oxygen levels, pH, salinity and turbidity. A classification is presented of the most distinctive adaptations,the various tactics that organisms apply to survive dry periods. The main strategies are dormancy (escape in time) and dispersal (escape in space). These adaptations may affect the impact of toxicants on individuals, populations and communities of temporary ponds. The physiological adaptations of species found in temporary ponds are likely to alter the sensitivity to pollutants of characteristic species. Results from laboratory experiments,for example, suggest that fairy shrimp (Branchiopoda, Anostraca) may react differently to heavy metals and pesticides as the standard test species Daphnia. Life history strategies influence recovery rates of populations after exposure to acutely toxic substances such as pesticides. It is also suggested that slow growth and decreased reproductive capacity of organisms caused by toxicants may, in ephemeral ponds, result in the failure of annual recruitment. Whether assemblages of organisms in temporary ponds are generally more vulnerable or more resilient than those in permanent waters or temperate regions could not be determined conclusively with the limited data available. Ecological concepts for studying the habitat and the development of risk assessment methods for temporary ponds are briefly discussed. PMID:9002434

  1. 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.

  2. The history and fate of the Nubian Sandstone Aquifer springs in the oasis depressions of the Western Desert, Egypt

    Science.gov (United States)

    Powell, Owen; Fensham, Rod

    2016-03-01

    Extraction of groundwater for agriculture has resulted in the loss of springs across arid regions of the globe. The history and fate are recorded of the artesian springs of Egypt's Western Desert, from ancient times to the present, spanning the rise and fall of the great civilisations from the Pharoanic dynasties to Persian, Greek and Roman conquests. The study area includes oases Kharga, Dakhla, Bahriya, Farafra and Siwa, and several outer and small oases around Siwa and the edge of the Qattara Depression. The region is hyper-arid, receiving 10 mm or less average annual precipitation and evaporation rates are in the vicinity of 3,000 mm/a. Groundwater in the oases is largely derived from bores discharging from the Nubian Sandstone Aquifer. Based on an extensive survey, conducted for the first time, attention is drawn to the rapid demise of springs as a result of modern irrigation schemes which continue to deplete groundwater supplies.

  3. Western values and the Russian energy weapon

    Science.gov (United States)

    Domingues, Bennett K.

    This thesis explores the competition between Russia and the West for the oil and gas resources of the Caspian Sea region, an area where far more is at stake than simply acquisition of new energy supplies. Ultimately, the "winner" of the competition for Caspian Sea energy resources will determine whether Russia will become the primary energy supplier for Europe in the future, or whether there will be alternative, non-Russian energy routes from East to West. The thesis uses a qualitative approach, drawing on scholarly books and articles, current affairs publications, energy firm websites, and other sources to compare the ethical aspects of the strategies used by Russia and the West, to determine whose strategy has been more successful, and to analyze what this means for the political, economic, and security future of Europe. As this thesis demonstrates, Russia recognizes the importance of energy as both an economic and foreign policy tool. To secure access to the resources of the Caspian Sea region, Russia has used bribery and strongman tactics to secure arrangements and contracts favorable to Russian interests. When a country does not capitulate to these tactics, Russia applies other measures to influence these countries' policies. This thesis draws on two recent examples, Ukraine and Georgia, to demonstrate how Russia has used its position as a supplier of energy resources to influence countries to adopt policies complementary to Russian interests, or to punish them for failing to do so. The effectiveness of these Russian tactics is an important precedent for the countries of the Caspian Sea region to keep in mind as they make decisions that will determine their economic and political future for decades to come. In contrast, the western strategy of promoting quality products and services, while ensuring safety and conducting business according to western ethical norms, has been less successful than western firms originally envisioned. Undoubtedly western firms have

  4. 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.

  5. 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...

  6. 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...

  7. 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

  8. 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.

  9. Assessment of Environment Control in Arid Area Green house coupled with Earth Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Kamlesh R. Jethva

    2016-04-01

    Full Text Available In hot arid regions, yields are low and unstable, growing season limited to one. Greenhouses can stabilize and improve yields and extend seasons. But their adoption is impeded by the requirement of large amount of water for (evaporative cooling. Arid Area Greenhouse (AAG is developed to reduce or eliminate this need by employing earth-tube-heat-exchanger (ETHE. ETHE was able to heat the greenhouse from 9°C to 22-23°C in 30 minutes in the cold winter nights. Static ventilation along with shading was effective for day time to control till early March. Subsequently ETHE was also operated. Yield of tomato in Arid Area Greenhouse was 1.5 to 2 times and water saving in AAG was 44% of that in open-field condition. ETHE and natural ventilation hold promise as environmental control devices for greenhouses in hot arid regions

  10. Survey on the construction of realization scenario of large-scale revegetation of arid regions; Daikibo ryokuka no jitsugenka scenario sakusei ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    In order to fix carbon dioxide as a measure to mitigate global warming, research of large-scale revegetation of arid regions has been conducted toward the ultimate goals of systematizing revegetation technologies centered on securing and using water resources, evaluating the feasibility of arid revegetation by extending the viewpoint to examine even rainfall increase by artificial means, and establishing a strategic program for large-scale revegetation. A trial revegetation feasibility map was made for a selected target region in Western Australia, and rough revegetation steps were formulated. Selection of proper region, introduction of technology, and planning were conducted by grasping environment of the target revegetation region. As a result, it was found that growth of plants is vigorous at the catchment areas due to the surface water transfer along the topography of surface in spite of poor rainfall. Obstruction of plant growth is partly caused by the corrosion of soil and accumulation of salt, but mainly caused by the shortage of water. Based on these data, ranking of proper regions was evaluated. When the technology is introduced in the region with A-rank, several times of water can be collected. 60 refs., 61 figs., 30 tabs.

  11. 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.

  12. Speleothem records of western Mediterranean. Hydrological variability along the Last Interglacial Period and marine linkages

    Science.gov (United States)

    Torner, Judit; Cacho, Isabel; Moreno, Ana; Stoll, Heather; Belmonte, Anchel; Sierro, Francisco J.; Frigola, Jaime; Martrat, Belen; Fornós, Joan; Arnau Fernández, Pedro; Hellstrom, John; Cheng, Hai; Edwards, R. Lawrence

    2016-04-01

    This study aims to identify and characterize regional hydrological variability in the western Mediterranean region in base to different geochemical parameters (δ18O, δ13C, and Mg/Ca ratios). Speleothems have been recovered from several caves located in southern central Pyrenees one and the others form the Balearic Islands. Their chronologies have been constructed in base on U/Th absolute dating and indicate that the speleothem sequences cover the end of the last interglacial and the glacial inception. One of the most remarkable features of the records is the intense and abrupt shift toward more arid conditions that marks the end of the last interglacial (MIS 5e). Furthermore, our speleothem records also show relatively humid but highly variable hydrological conditions during the interstadial periods from MIS 5c to 5a. These speleothem records have been compared with new generated western Mediterranean marine records from the Balearic Sea (MD99-2343) and Alboran Sea (OPD-977). Marine records include (1) proxies of sea surface temperature and changes in evaporation-precipitation rates based on pair analysis of δ18O and the Mg/Ca ratios in planktonic foraminifera Globigerina bulloides; (2) proxies of deep-water currents associated with the Western Mediterranean Deep Water (WMDW) based on grain size analyses. The results reveal that arid conditions on land were coeval with cold sea surface sub-stages (MIS 5b and 5d), and also with increases in the intensity of the WMDW-related currents. By contrast, humid and hydrological unstable atmosphere conditions were synchronous with sea surface warm sub-stages, and lower WMDW-related currents intensities (MIS 5a, c and e). Consequently, our results highly evidence a strong atmospheric-oceanic coupling, involving parallel changes in both surface but also deep western Mediterranean Sea conditions during the last interglacial period and the glacial inception.

  13. The Late Quaternary biogeographic histories of some Great Basin mammals (western USA)

    Science.gov (United States)

    Grayson, Donald K.

    2006-11-01

    The Great Basin of arid western North America provides one of the most detailed late Pleistocene and Holocene mammal records available for any part of the world, though the record is by far strongest for small mammals. Of the 35 genera of now-extinct North American Pleistocene mammals, 19 are known to have occurred in the Great Basin, a list that is likely to be complete or nearly so. Of these 19, seven can be shown to have survived beyond 12,000 radiocarbon years ago, a proportion similar to that for North America as a whole. Horses, camels, mammoth, and helmeted musk-oxen appear to have been the most abundant of these genera. Pygmy rabbits ( Brachylagus idahoensis), yellow-bellied marmots ( Marmota flaviventris), and bushy-tailed woodrats ( Neotoma cinerea) declined in abundance at the end of the Pleistocene, at about the same time as populations south of their current arid western distributional boundary were extirpated. Subsequent declines occurred during the hot/dry middle Holocene. Pygmy rabbits also declined as modern pinyon-juniper woodlands developed across the Great Basin. The Snake Range of eastern Nevada has seen the late Pleistocene or Holocene extinction of both northern pocket gophers ( Thomomys talpoides) and pikas ( Ochotona princeps). Coupled with the rarity of yellow-bellied marmots here, these histories make the Snake Range a biogeographic oddity. These and other Great Basin mammal histories provide significant insights into the possible responses of Great Basin small mammals to global warming.

  14. Western Gas Sands Project status report

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, C.H.

    1978-06-30

    A summary is presented of the progress of government sponsored projects undertaken to increase gas production from low permeability gas sands of the western United States during May, 1978. Background information is given in the September 1977 Status Report, NVO/0655-100. The Department of Energy's (DOE) Nevada Operations Office (NVO), is finalizing a Request for Proposal (RFP) covering Technical and Administrative Support for the Project Manager for FY79. C. H. Atkinson, the Western Gas Sands Project (WGSP) Manager, was an observer of the third MHF treatment of Mobil Research and Development Corporation's well No. F-31-136. The fracture was performed on May 10, 1978. R. L. Mann of CER Corporation, met with Dr. Steve Holditch of Texas A and M University to discuss the utilization of the PDP 11/10 computer to be installed in the Mobile Well Test Facility. The USGS is continuing geological and geophysical studies in the four primary study areas. Two flights were made in preparation for low-level olique photography. The Bartlesville Energy Research Center (BERC) and participating National Laboratories, funded by DOE, are continuing their work in the area of research and development. The emphasis is on the development of new tools and instrumentation systems, rock mechanics, mathematical modeling, and data analysis. Mitchell Energy Corporation, Houston, Texas was awarded DOE Contract EF-78-C-08-1547 on March 15, 1978. Field work under this contract is scheduled to begin in July, 1978, with the drilling of a new well.

  15. Competitive edge of western coal

    International Nuclear Information System (INIS)

    This paper expresses views on the competitive advantages of one of the nation's most remarkable energy resources--Western coal. It covers utilization of Western coal, and its advantages. The Arkansas Power and Light Company and its demand for coal are also covered

  16. Ele não quer com camisinha e eu quero me prevenir: exposição de adolescentes do sexo feminino às DST/aids no semi-árido nordestino He does not want it with condom and I want to protect myself: exposure of female adolescents to STD/AIDS in the semi-arid region of the Brazilian northeast

    Directory of Open Access Journals (Sweden)

    Juliana Sampaio

    2011-03-01

    semi-arid region located in the Northeast of Brazil. The applied methodology was supported by the qualitative approach in health, and Discursive Practices and Production of Meaning (Spink, 2004; Medrado and Spink, 1999 were used as the theoretical and methodological model. Three methodological strategies were used for data collection: 1,024 hours of participant observation, 72 semi-structured interviews and 36 focus groups, comprising two groups of actors: 72 professionals of 8 health teams and 360 adolescents of both sexes. From the analysis of results it was possible to verify that the Northeastern reality is permeated by characteristics that make the women vulnerable to STD / AIDS, such as: a low educational levels; b unequal gender relations; c absence of a prevention policy targeted at teenagers; d lack of bonds between health professionals and the population; e the frequent understanding of health services as a space exclusively for women. In light of this context, we point to the need of policies of integral health care to adolescents that approach the sexual and reproductive rights in a gender perspective for the effective prevention of STD / AIDS, exerting a direct impact on improving the quality of their lives.

  17. 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...

  18. 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...

  19. 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...

  20. Deletion of Arid1a in Reproductive Tract Mesenchymal Cells Reduces Fertility in Female Mice.

    Science.gov (United States)

    Wang, Xiyin; Khatri, Shikha; Broaddus, Russell; Wang, Zhong; Hawkins, Shannon M

    2016-04-01

    Women with endometriosis can suffer from decreased fecundity or complete infertility via abnormal oocyte function or impaired placental-uterine interactions required for normal pregnancy establishment and maintenance. Although AT-rich interactive domain 1A (SWI-like) (ARID1A) is a putative tumor suppressor in human endometrial cancers and endometriosis-associated ovarian cancers, little is known about its role in normal uterine function. To study the potential function of ARID1A in the female reproductive tract, we generated mice with a conditional knockout of Arid1a using anti-Müllerian hormone receptor 2-Cre Female Arid1a conditional knockout mice exhibited a progressive decrease in number of pups per litter, with a precipitous decline after the second litter. We observed no tumors in virgin mice, although one knockout mouse developed a uterine tumor after pregnancy. Unstimulated virgin female knockout mice showed normal oviductal, ovarian, and uterine histology. Uteri of Arid1a knockout mice showed a normal decidualization response and appropriate responses to estradiol and progesterone stimulation. In vitro studies using primary cultures of human endometrial stromal fibroblasts revealed that small interfering RNA knockdown of ARID1A did not affect decidualization in vitro. Timed pregnancy studies revealed the significant resorption of embryos at Embryonic Day 16.5 in knockout mice in the third pregnancy. In addition to evidence of implantation site hemorrhage, pregnant Arid1a knockout mice showed abnormal placental morphology. These results suggest that Arid1a supports successful pregnancy through its role in placental function. PMID:26962117

  1. Optical satellite pictures - The up to date source for discharge determination in arid countries

    OpenAIRE

    Mett, Michael; Aufleger, Markus

    2009-01-01

    Many arid countries suffer severe water scarcity. Often lacking knowledge about hydrologic features like discharge prohibits the utilisation of valuable water resources. In this paper the basic approach is described to derive information about runoff water in arid landscapes by using optical satellite images. Wadi systems are highly sensitive regarding fluviomorphologic changes which are induced by rare flood events. Changes of river pattern, river width, sinuosity and so on correspond to dur...

  2. Archipelago of endolithic microbial life in the hyper arid core of the Atacama Desert

    OpenAIRE

    Wierzchos, Jacek; Davila, Alfonso F.; Diruggiero, J.; Ríos, Asunción de los; Valea, Sergio; Cámara Gallego, Beatriz; Artieda, Octavio; Speranza, Mariela; Robinson, Courtney K; Souterre, T.; Souza Egipsy, Virginia; Ascaso, Carmen

    2012-01-01

    The hyper-arid core of the Atacama Desert is considered the driest and most life-limited place on Earth. As such, this desert is an ideal environment to study the survival and biological adaptation strategies of microorganisms to this extremely dry environment. The extreme aridity of the Atacama Desert allows us to address questions such as the potential for life in extraterrestrial environments such as the surface of Mars. Our results over the last six years of searching for micr...

  3. Groundwater prospecting, drilling and well construction in hard rocks in semi-arid regions: an overview

    OpenAIRE

    Chambel, António

    2012-01-01

    In semi-arid and arid areas rock weathering is normally much less deep that in rainy areas. So, rocks tend to be more near the topographic surface. These climatic conditions also generate much less vegetation, which in all the cases clearly favours a direct observation of rock condition, fracturing or weathering. By other side, aquifers in hard rocks present specificities in relation to water presence and movement that implies a different approach when dealing with groundwater prospecting....

  4. 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...

  5. 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. ...

  6. Distribution of Actual Evapotranspiration over Qaidam Basin, an Arid Area in China

    OpenAIRE

    Xiaomei Jin; Renhong Guo; Wei Xia

    2013-01-01

    Evapotranspiration is a major loss flux of the water balance in arid and semi-arid areas. The estimation of actual evapotranspiration has significance for hydrological and environmental purposes. The Surface Energy Balance System (SEBS) algorithm was applied to estimate actual evapotranspiration in the Qaidam Basin and its eight hydrological sub-regions, Northwest China. There were 3,036 cloud-free and atmospherically corrected MODIS satellite images from 2001 to 2011 used in the SEBS algorit...

  7. Spatial-Temporal Variation of Aridity Index of China during 1960–2013

    OpenAIRE

    Huiping Huang; Yuping Han; Mingming Cao; Jinxi Song; Heng Xiao

    2016-01-01

    Aridity index, as the ration of potential evapotranspiration and precipitation, is an important indicator of regional climate. GIS technology, Morlet wavelet, Mann-Kendall test, and principal component analysis are utilized to investigate the spatial-temporal variation of aridity index and its impacting factors in China on basis of climate data from 599 stations during 1960–2013. Results show the following. (1) Boundaries between humid and semihumid region, and semihumid and semiarid region c...

  8. 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...

  9. 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.

  10. Uranium in western Europe

    International Nuclear Information System (INIS)

    Uranium has been in use in Europe since the Middle Ages, and working of uraniferous minerals on an industrial scale for the production of radium began in Portugal and Czechoslovakai in 1904. Mining began soon after World War II for the production of fissile material. Western Europe's uranium resources represent about a tenth of the world's resources, of 486 950 tonnes recoverable at $130 per kg or less. Production in 1978 was 2 513 tonnes of uranium. The principal producing countries were the Federal Republic of Germany, Spain, France, and Portugal. Uraniferous vein deposits occur in the Moldanubian granites, the Iberian Meseta, the Armorican massif, the Massif Central, and the Black Forest. Deposits associated with sedimentary rocks occur in the Cambrian shales of Ranstad, the Permian lutites and silts of Lodeve, and in grits and sandstones elsewhere. Volcanic deposits are present in Alpine areas. The current rate of exploration must be maintained if the energy needs of Europe predicted for the year 2000 are to be met. (L.L.)

  11. Understanding the erosion of semi-arid landscapes subject to vegetation change: a combined approach using monitoring, isotope and 14c analysis

    International Nuclear Information System (INIS)

    The degradation of grasslands is a common problem across semi-arid areas worldwide.over the last 150 years much of the south-Western USA has experienced significant land degradation, with desert grasslands becoming dominated by shrubs and concurrent changes in runoff and erosion which are thought to propagate further the process of degradation. Field-based experiments were carried out to determine how runoff and erosion vary at stages over a transition from a black grama (Bouteloua eriopoda) grassland to creosote bush (Larrea tridentata) shrub land at the Sevilleta NWR LTER site in New Mexico. δ13 C and δ15 N analyses were carried out to investigate the age and potential provenance of eroded sediment. (Author) 4 refs.

  12. Sources and transport of nitrogen in arid urban watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Rebecca L.; Turnbull, Laura; Earl, Stevan; Grimm, Nancy B.; Riha, Krystin M.; Michalski, Greg; Lohse, Kathleen; Childers, Daniel L.

    2014-06-03

    Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3–) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3– (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3– during storms from 10 nested arid urban watersheds that varied in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover—retention basins, pipes, and grass cover—dictated the sourcing of NO3– in runoff. Urban watersheds can be strong sinks or sources of N to stormwater depending on the proportion of rainfall that leaves the watershed as runoff, but we found no evidence that denitrification occurred during storms. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the timescale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.

  13. 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.

  14. Object-based classification of semi-arid wetlands

    Science.gov (United States)

    Halabisky, Meghan; Moskal, L. Monika; Hall, Sonia A.

    2011-01-01

    Wetlands are valuable ecosystems that benefit society. However, throughout history wetlands have been converted to other land uses. For this reason, timely wetland maps are necessary for developing strategies to protect wetland habitat. The goal of this research was to develop a time-efficient, automated, low-cost method to map wetlands in a semi-arid landscape that could be scaled up for use at a county or state level, and could lay the groundwork for expanding to forested areas. Therefore, it was critical that the research project contain two components: accurate automated feature extraction and the use of low-cost imagery. For that reason, we tested the effectiveness of geographic object-based image analysis (GEOBIA) to delineate and classify wetlands using freely available true color aerial photographs provided through the National Agriculture Inventory Program. The GEOBIA method produced an overall accuracy of 89% (khat = 0.81), despite the absence of infrared spectral data. GEOBIA provides the automation that can save significant resources when scaled up while still providing sufficient spatial resolution and accuracy to be useful to state and local resource managers and policymakers.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. Modeling Episodic Surface Runoff in an Arid Environment

    Science.gov (United States)

    Waichler, S. R.; Wigmosta, M. S.

    2003-12-01

    Methods were developed for estimating episodic surface runoff in arid eastern Washington, USA. Small (1--10 km2) catchments in this region with mean annual precipitation around 180 mm produce runoff in about half the years, and such events usually occur during winter when a widespread cold snap and possible snow accumulation is followed by warmer temperatures and rainfall. Existence of frozen soil appears to be a key factor, and a moving average of air temperature is an effective predictor of soil temperature. The watershed model DHSVM simulates snow accumulation and ablation reasonably well at a monitoring location, but the same model applied in distributed mode across a 850 km2 basin overpredicts runoff. Inadequate definition of local meteorology appears to limit the accuracy of runoff predictions. However, runoff estimates of sufficient quality to support modeling of long-term groundwater recharge and sediment transport may be found in focusing on recurrence intervals and volumes rather than hydrographs. Usefulness of upland watershed modeling to environmental management of the Hanford Site and an adjacent military reservation will likely improve through sensitivity analysis of basic assumptions about upland water balance.

  2. Agronomic evaluation of barley mutants under semi-arid conditions

    International Nuclear Information System (INIS)

    A mutant line, Cyp M9, selected from a population of the barley variety Attiki treated with gamma rays, was evaluated against commercial varieties for the grain yield, yield components, and the protein content and yield in 15 trials. The grain yield of Cyp M9 was 14% higher than that of its mother variety, Attiki, and similar to those of the best commercial varieties, Athenais and Kantara. The protein yield of the mutant line (711 kg/ha) was higher than those of the commercial varieties. Regression analyses of the varietal grain yield and the environmental mean showed that the response of Cyp M9 to improved environmental conditions was greater than those of the commercial varieties. Furthermore, Cyp M9 showed a better response to higher rainfall conditions than Kantara. In general, the mutant Cyp M9 responded to environmental changes in the semi-arid environment in a manner similar to, or better than, those of the commercial varieties. (author). 5 refs, 1 fig., 1 tab

  3. 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.

  4. 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.

  5. Western Disturbances: A review

    Science.gov (United States)

    Dimri, A. P.; Niyogi, D.; Barros, A. P.; Ridley, J.; Mohanty, U. C.; Yasunari, T.; Sikka, D. R.

    2015-06-01

    Cyclonic storms associated with the midlatitude Subtropical Westerly Jet (SWJ), referred to as Western Disturbances (WDs), play a critical role in the meteorology of the Indian subcontinent. WDs embedded in the southward propagating SWJ produce extreme precipitation over northern India and are further enhanced over the Himalayas due to orographic land-atmosphere interactions. During December, January, and February, WD snowfall is the dominant precipitation input to establish and sustain regional snowpack, replenishing regional water resources. Spring melt is the major source of runoff to northern Indian rivers and can be linked to important hydrologic processes from aquifer recharge to flashfloods. Understanding the dynamical structure, evolution-decay, and interaction of WDs with the Himalayas is therefore necessary to improve knowledge which has wide ranging socioeconomic implications beyond short-term disaster response including cold season agricultural activities, management of water resources, and development of vulnerability-adaptive measures. In addition, WD wintertime precipitation provides critical mass input to existing glaciers and modulates the albedo characteristics of the Himalayas and Tibetan Plateau, affecting large-scale circulation and the onset of the succeeding Indian Summer Monsoon. Assessing the impacts of climate variability and change on the Indian subcontinent requires fundamental understanding of the dynamics of WDs. In particular, projected changes in the structure of the SWJ will influence evolution-decay processes of the WDs and impact Himalayan regional water availability. This review synthesizes past research on WDs with a perspective to provide a comprehensive assessment of the state of knowledge to assist both researchers and policymakers, and context for future research.

  6. IN WESTERN SIBERIA

    Directory of Open Access Journals (Sweden)

    Chizhikov Il'ja Aleksandrovich

    2012-10-01

    along the oil transportation route that connected three Salym oil fields in Western Siberia.

  7. Decommissioning in western Europe

    International Nuclear Information System (INIS)

    This report gives an overview of the situation in Western Europe. The original aim was to focus on organisational and human issues with regard to nuclear reactor decommissioning, but very few articles were found. This is in sharp contrast to the substantial literature on technical issues. While most of the reports on decommissioning have a technical focus, several provide information on regulatory issues, strategies and 'state of the art'. The importance of the human and organizational perspective is however discovered, when reading between the lines of the technical publications, and especially when project managers summarize lessons learned. The results are to a large extent based on studies of articles and reports, mainly collected from the INIS database. Decommissioning of nuclear facilities started already in the sixties, but then mainly research and experimental facilities were concerned. Until now about 70 reactors have been shutdown world-wide. Over the years there have been plenty of conferences for exchanging experiences mostly about technical matters. Waste Management is a big issue. In the 2000s there will be a wave of decommissioning when an increasing amount of reactors will reach the end of their calculated lifetime (40 years, a figure now being challenged by both life-extension and pre-shutdown projects). Several reactors have been shut-down for economical reasons. Shutdown and decommissioning is however not identical. A long period of time can sometimes pass before an owner decides to decommission and dismantle a facility. The conditions will also differ depending on the strategy, 'immediate dismantling' or 'safe enclosure'. If immediate dismantling is chosen the site can reach 'green-field status' in less than ten years. 'Safe enclosure', however, seems to be the most common strategy. There are several pathways, but in general a safe store is constructed, enabling the active parts to remain in safe and waterproof conditions for a longer period of

  8. Using multiple environmental methods to estimate groundwater discharge into an arid lake (Dakebo Lake, Inner Mongolia, China)

    Science.gov (United States)

    Su, Xiaosi; Cui, Geng; Du, Shanghai; Yuan, Wenzhen; Wang, Huang

    2016-06-01

    It is important to have both a qualitative and quantitative understanding of the hydraulic exchange between groundwater and surface water to support the development of effective management plans for sustainable use of water resources. Groundwater is a major source of surface-water recharge and plays an important role in maintaining the integrity of ecosystems, especially within wetlands in semi-arid regions. The Ordos Desert Plateau of Inner Mongolia (China) is a vulnerable ecosystem that suffers from an extreme lack of water. The hydraulic exchange between groundwater and lake water in Dakebo Lake (the largest of hundreds of lakes on the Ordos Desert Plateau) was evaluated using multiple environmental methods. Continuous monitoring of the groundwater and lake-water levels indicated that the lake was recharged vertically by groundwater. Application of hydrodynamic and temperature tracing methods to the western side of the lake indicated that the rate of groundwater discharge to the lake was about 2 × 10-6 to 3 × 10-6 m/s in spring, summer, and autumn, but that there was no recharge in winter because the hypolentic zone (HZ) was frozen. Mixing ratios of groundwater and lake water in the HZ, estimated from the 18O and 2H ratios, showed that there were spatial variations in the hydrodynamic exchange between groundwater and lake water within the HZ.

  9. Long-term spatio-temporal precipitation variability in arid-zone Australia and implications for groundwater recharge

    Science.gov (United States)

    Acworth, R. Ian; Rau, Gabriel C.; Cuthbert, Mark O.; Jensen, Evan; Leggett, Keith

    2016-01-01

    Quantifying dryland groundwater recharge as a function of climate variability is becoming increasingly important in the face of a globally depleted resource, yet this remains a major challenge due to lack of adequate monitoring and the complexity of processes involved. A previously unpublished and unique dataset of high density and frequency rainfall measurements is presented, from the Fowlers Gap Arid Zone Research Station in western New South Wales (Australia). The dataset confirms extreme spatial and temporal variability in rainfall distribution which has been observed in other dryland areas and is generally explained by the dominance of individual storm cells. Contrary to previous observations, however, this dataset contains only a few localised storm cells despite the variability. The implications of spatiotemporal rainfall variability on the estimation of groundwater recharge is assessed and show that the most likely recharge mechanism is through indirect and localised, rather than direct, recharge. Examples of rainfall and stream gauge height illustrate runoff generation when a spatially averaged threshold of 15-25 mm (depending on the antecedent moisture conditions) is exceeded. Preliminary assessment of groundwater levels illustrates that the regional water table is much deeper than anticipated, especially considering the expected magnitude of indirect and localised recharge. A possible explanation is that pathways for indirect and localised recharge are inhibited by the large quantities of Aeolian dust observed at the site. Runoff readily occurs with water collecting in surface lakes which slowly dry and disappear. Assuming direct groundwater recharge under these conditions will significantly overestimate actual recharge.

  10. Production of Hybrids between Western Gray Wolves and Western Coyotes

    OpenAIRE

    Young, Julie K; Mech, L. David; Christensen, Bruce W.

    2014-01-01

    Using artificial insemination we attempted to produce hybrids between captive, male, western, gray wolves (Canis lupus) and female, western coyotes (Canis latrans) to determine whether their gametes would be compatible and the coyotes could produce and nurture offspring. The results contribute new information to an ongoing controversy over whether the eastern wolf (Canis lycaon) is a valid unique species that could be subject to the U. S. Endangered Species Act. Attempts with transcervically ...

  11. 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.

  12. Some cirad activities and perspectives in water and nutrient management in arid and semi-arid regions using nuclear techniques

    International Nuclear Information System (INIS)

    The Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement has conducted collaborative research with national agricultural research services in several semi-arid regions that has led to a general understanding of the relationship between water consumption and growth, and crop responses to fertilizers. However, farmers' adoption of practices arising from the research has been minimal. Current effort is directed at overcoming limits to adoption, firstly by understanding the interaction of fertilizer response and water supply, especially through modelling, in order to quantify risk criteria from the farmer's point of view. Secondly, research now takes account of the whole cropping system, including labour availability, access to credit, livestock management, etc., with a multidisciplinary approach. Approaches that offer sustainability are improved intercropping systems, retention of crop residues, increased plant cover, and agroforestry. There are important technical gaps in understanding of how these systems should operate. The allocation of nutrients and water among the components of intercropped or agroforestry systems is not understood and solutions could lead to improved spatial arrangements. The integrated effects of residues on runoff, soil evaporation, crop transpiration and N mineralization are not quantified. In these and other problems, the full range of risks as well as benefits need to be evaluated. (author)

  13. Western water and climate change.

    Science.gov (United States)

    Dettinger, Michael; Udall, Bradley; Georgakakos, Aris

    2015-12-01

    The western United States is a region long defined by water challenges. Climate change adds to those historical challenges, but does not, for the most part, introduce entirely new challenges; rather climate change is likely to stress water supplies and resources already in many cases stretched to, or beyond, natural limits. Projections are for continued and, likely, increased warming trends across the region, with a near certainty of continuing changes in seasonality of snowmelt and streamflows, and a strong potential for attendant increases in evaporative demands. Projections of future precipitation are less conclusive, although likely the northern-most West will see precipitation increases while the southernmost West sees declines. However, most of the region lies in a broad area where some climate models project precipitation increases while others project declines, so that only increases in precipitation uncertainties can be projected with any confidence. Changes in annual and seasonal hydrographs are likely to challenge water managers, users, and attempts to protect or restore environmental flows, even where annual volumes change little. Other impacts from climate change (e.g., floods and water-quality changes) are poorly understood and will likely be location dependent. In this context, four iconic river basins offer glimpses into specific challenges that climate change may bring to the West. The Colorado River is a system in which overuse and growing demands are projected to be even more challenging than climate-change-induced flow reductions. The Rio Grande offers the best example of how climate-change-induced flow declines might sink a major system into permanent drought. The Klamath is currently projected to face the more benign precipitation future, but fisheries and irrigation management may face dire straits due to warming air temperatures, rising irrigation demands, and warming waters in a basin already hobbled by tensions between endangered fisheries

  14. Analyzing and modelling of flow transmission processes in river-systems with a focus on semi-arid conditions

    OpenAIRE

    Cunha Costa, Alexandre

    2012-01-01

    One of the major problems for the implementation of water resources planning and management in arid and semi-arid environments is the scarcity of hydrological data and, consequently, research studies. In this thesis, the hydrology of dryland river systems was analyzed and a semi-distributed hydrological model and a forecasting approach were developed for flow transmission processes in river-systems with a focus on semi-arid conditions. Three different sources of hydrological data (streamflow ...

  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. Pioneer dendroclimatological research in the Western Turkmenistan

    Science.gov (United States)

    Berdnikova, Alina; Matskovsky, Vladimir; Kurbanov, Redzhep

    2016-04-01

    Turkmenistan is a very special region in Central Asia where the desert covers 80% of the territory. Water supply is a subject of state importance in Turkmenistan. To understand the mechanisms that affect the amount of precipitation in the region on decadal and centennial time scales long records of atmospheric precipitation are necessary. Unfortunately such records are sparse and short in the region. Tree rings are natural archive that store information about environmental conditions of the past. Previously tree rings have been successfully used for hydroclimate reconstructions covering the last millennium. Such reconstructions uncovered possible climatic causes of many social cataclysms in human history. In arid regions tree rings are especially useful for hydroclimate reconstructions, explaining around 60-80% of variability of instrumental records. Paleogeographic reconstructions for the Late Holocene based on dendroclimatology can reveal the climatic characteristics of periods when Aral Sea basin was connected with the Caspian sea. The other possible perspective of our research is revealing the paleoclimate characteristics for Western Turkmenistan describing evaporation and precipitation - the basic indicators for understanding Caspian sea-level change. The aim of this study was to assess the potential of dendroclimatological method in Turkmenistan for the purpose of hydroclimatological reconstructions. These reconstructions may significantly extend the existing instrumental records of atmospheric precipitation in the region. Study region is situated along the southwestern border of the Turkmenistan, in northern piedmont of the Kopetdag range. We sampled several species: turkman juniper (Juniperus turcomanica), black pine (Pinus nigra), oriental plane (Platanus orientalis), paper mulberry (Broussonetia papyrifera) and osage orange (Maclura pomifera), but only juniper chronology has been constructed and analyzed so far. Although old trees are rare in Turkmenistan

  17. 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

  18. Experiencias en Western Australia

    Directory of Open Access Journals (Sweden)

    M.A. Pérez Fernández

    2008-01-01

    Full Text Available Décadas de uso inadecuado de los recursos naturales en Australia han llevado a la extinción de numerosas especies autóctonas. Aprendiendo de sus propios errores, se han inicido recientemente diferentes proyectos de conservación en los que participan diversos agentes interesados. La Región de los Central Ranges, en el Desierto de Gibson, pertenece al pueblo aborigen Ngaanyatjarra. En los años 90 se llevó a cabo una campaña de recolección de organismos, patrocinada por el Museo de Western Australia y el Departamento de Conservación Ambiental (DEC, en la que participaron miembros de la comunidad Ngaanyatjarra, conocedores y cuidadores del territorio. El resultado científico se tradujo en la identificación de dos nuevas especies, así como numerosas nuevas citas de plantas y animales para el territorio. La minería es una de las actividades más impactantes en Australia, pero la concienciación social ha llevado a que las compañías desarrollen importantes campañas de protección de especies. El mulgara (Dasycercus cristicaula ocupaba zonas que hoy en día se dedican a la minería, y de las que prácticamente ha desaparecido. Un programa de investigación financiado por la empresa Resolute Resources y dirigido por el Departamento de Conservación y Manejo del Territorio (CALM ha permitido identificar poblaciones de este marsupial carnívoro y diseñar un programa de manejo cuyo objetivo es evitar actuaciones incompatibles con su actividad biológica. El resultado más relevante en ambas iniciativas ha sido la colaboración entre diferentes agentes implicados, con intercambio de conocimientos y experiencias. Especialmente importante ha sido la posibilidad de diseñar planes de manejo y actuación sobre el territorio, orientados a la preservación de valores naturales y culturales antiguos.

  19. Western Pacific Typhoon Aircraft Fixes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Western Pacific typhoon aircraft reconnaissance data from the years 1946 - 1965 and 1978, excluding 1952, were transcribed from original documents, or copy of...

  20. The Evolution of a Freshwater Wetland in a Semi-arid Environment, Loboi Swamp, Kenya

    Science.gov (United States)

    Ashley, G. M.; Driese, S. G.; Mworia, J. M.; Muasya, A. M.; Hover, V. C.; Owen, R. B.; Goman, M. F.

    2002-12-01

    Loboi Swamp is situated near the equator on the western fault-bounded margin of an asymmetric half-graben within the East African Rift valley. The freshwater wetland is ~ 3km2 and developed during mid to late Holocene on the low relief floodplain of the axial Loboi River. The swamp is groundwater-fed by several springs and seeps associated with the border fault system. Spring waters are ~35°C, with pH ~6.4-6.9 and the water compositions suggest that the sources are shallow, and dominated by meteoric water with little contributed by deep re-circulating fluids. The climate is semi-arid. P is ~700 mm/yr on the valley bottom and 1200mm/yr in the adjacent highlands; ET is estimated to be ~2500 mm/yr. Variation in precipitation occurs on a range of time scales: semi-annual monsoonal rains in Nov. and April; El Nino and La Nina periods every 5-7 years; and long term variations in climate are also likely, such as, orbitally-forced Precession cycles (~20ka). The modern swamp is dominated by Typha domingensis Pers. (~80%) and Cyperus papyrus L. (20%), a crocodile habitat. The stratigraphy revealed in a soil pit and 8 piston cores (1.5-4 m long) records the formation, evolution and maybe the beginning of the demise of the wetland. Basal sediments are floodplain (sandy silts) that fine upward to f. silt and clay and are capped with organic-rich sediment (peat). Subparallel siderite concretion horizons in the silts indicate that Fe-reducing conditions developed as the basal sediments were flooded by the developing wetland. The peat is thickest (1.5 m) in the spring-proximal area near the fault and thins to 0.30m in the spring-distal areas. The appearance and expansion of peat indicates moister climate, however preliminary pollen analyses reveals that Cyperaceae and Tpyha are less abundant now than earlier suggesting a change from moister to drier conditions after the development of the swamp. Surface and porewater compositions in the swamp are modified by processes of

  1. Trends in feed supply of three browse species in a semi-arid environment of Nigeria

    International Nuclear Information System (INIS)

    The feed supply trends of three important browse species, Anogeissus leiocarpus, Balanites aegyptiaca and Sclerocarya birrea was monitored in the Zamfara reserve of north-western Nigeria (6 deg. 45' - 7 deg. 10' E and 12 deg. 00' - 13 deg. 10'N), between peak period of production (September) and peak period of the dry season (April). 36 trees, 12 of each species were randomly selected and marked on a 3000 x 500 m transect. On each tree 12 twigs of one centimeter diameter thick were randomly selected and their leaves harvested and weighed fresh. After weighing, samples from each species were thoroughly mixed and 100 g sub samples were collected for oven drying and dry matter (DM) determination. This procedure was repeated at an interval of five weeks between 2002 and 2003. The experiment was laid as a Randomized Complete Block Design. Data were subjected to analysis of variance (ANOVA), where there were significant differences between treatment means, Duncan Multiple Range Test method was used for comparison. Results were presented of the DM production of the different browse species at the different time intervals. Anogeissus leiocarpus produced the highest (P < 0.001) amount of DM at all the periods, except in the month of March. Dry matter yield of the specie declined progressively from September (33.0 g) to March (9.0 g). Dry matter yield of Balanites aegyptiaca and Sclerocarya birrea was not consistent throughout the study period, however the former produced more yield (P < 0.001) than the latter (13.3 vs. 8.4 g, respectively). In the month of March, Sclerocarya birrea produced no leaves at all. On the overall, the mean DM yield of all the species was highest in November (23.3g) and lowest in March (6.3 g). The decline in the DM yield of all the species during this period could be due to physiological stress resulting from lack of moisture. It could also be due to competition of the grazing animals that switch from grazing to browsing during this period, which

  2. let-7 Modulates Chromatin Configuration and Target Gene Repression through Regulation of the ARID3B Complex

    Directory of Open Access Journals (Sweden)

    Tsai-Tsen Liao

    2016-01-01

    Full Text Available Let-7 is crucial for both stem cell differentiation and tumor suppression. Here, we demonstrate a chromatin-dependent mechanism of let-7 in regulating target gene expression in cancer cells. Let-7 directly represses the expression of AT-rich interacting domain 3B (ARID3B, ARID3A, and importin-9. In the absence of let-7, importin-9 facilitates the nuclear import of ARID3A, which then forms a complex with ARID3B. The nuclear ARID3B complex recruits histone demethylase 4C to reduce histone 3 lysine 9 trimethylation and promotes the transcription of stemness factors. Functionally, expression of ARID3B is critical for the tumor initiation in let-7-depleted cancer cells. An inverse association between let-7 and ARID3A/ARID3B and prognostic significance is demonstrated in head and neck cancer patients. These results highlight a chromatin-dependent mechanism where let-7 regulates cancer stemness through ARID3B.

  3. The Western Environmental Technology Office (WETO), Butte, Montana, technology summary

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This document has been prepared by the DOE Environmental Management (EM) Office of Technology Development (OTD) to highlight its research, development, demonstration, testing, and evaluation activities funded through the Western Environmental Technology Office (WETO) in Butte, Montana. Technologies and processes described have the potential to enhance DOE`s cleanup and waste management efforts, as well as improve US industry`s competitiveness in global environmental markets. WETO`s environmental technology research and testing activities focus on the recovery of useable resources from waste. Environmental technology development and commercialization activities will focus on mine cleanup, waste treatment, resource recovery, and water resource management. Since the site has no record of radioactive material use and no history of environmental contamination/remediation activities, DOE-EM can concentrate on performing developmental and demonstration activities without the demands of regulatory requirements and schedules. Thus, WETO will serve as a national resource for the development of new and innovative environmental technologies.

  4. Western economics versus Buddhist economics

    OpenAIRE

    Laszlo Zsolnai

    2007-01-01

    The paper explores Buddhist economics as a major alternative to the Western economic mindset. Buddhism is centred on want negation and purification of the human character. Buddhist economics, developed by Schumacher, Payutto, Welford and others, challenges the basic principles of modern Western economics: (1) profit-maximisation, (2) cultivating desires, (3) introducing markets, (4) instrumental use of the world, and (5) self-interest-based ethics. Buddhist economics proposes alternative prin...

  5. Modeling and Managing Regional Aquifers in Arid Countries

    Science.gov (United States)

    Schüth, C.; Rausch, R.

    2009-12-01

    Most of the regional aquifers in arid countries were recharged many thousand years ago when the climate was much wetter than today. Therefore, most of the groundwater stored in the aquifers is fossil water. The aquifers are in a state of constant depletion as recent groundwater recharge is much smaller than the outflow. A prerequisite for the smart management of such groundwater resources is a sound understanding of the aquifer system based on reliable data and robust simulation models. Mathematical groundwater models are one of the tools available that can consider a complex array of aquifer variables and allow these variables to interact with themselves. Exploring these interactions with a model can reveal how an aquifer behaves. Once a model is working properly, it can be used to make predictions for managing groundwater resources, such as predicting how groundwater levels might respond to increased pumping or drought, testing different management scenarios etc. Furthermore, groundwater models describing regional aquifers in arid regions must be considered to be in a transient state and consider the entire extent of the aquifer. The introduction of artificial boundaries is not possible and lead to wrong estimations. Within the modeling process the reduction and estimation of uncertainties is required, which leads to the “inverse problem” in groundwater modeling. Strategies for the reduction and estimation of uncertainties are needed. Problems are (1) the ill-posedness of parameter estimation, (2) that no unique solution may exist, and (3) that measurement errors make the results unreliable. Ways out are the reduction of degrees of freedom by introducing geological ‘a priori’ knowledge as well as the joint use of head, flow and/or concentration measurements, and the estimation of uncertainty. This concept is demonstrated by examples of model development for regional aquifers on the Arabian Peninsula, e.g. ‘a priori’ knowledge is introduced into the

  6. Western Wind and Solar Integration Study: Hydropower Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Acker, T.; Pete, C.

    2012-03-01

    The U.S. Department of Energy's (DOE) study of 20% Wind Energy by 2030 was conducted to consider the benefits, challenges, and costs associated with sourcing 20% of U.S. energy consumption from wind power by 2030. This study found that with proactive measures, no insurmountable barriers were identified to meet the 20% goal. Following this study, DOE and the National Renewable Energy Laboratory (NREL) conducted two more studies: the Eastern Wind Integration and Transmission Study (EWITS) covering the eastern portion of the U.S., and the Western Wind and Solar Integration Study (WWSIS) covering the western portion of the United States. The WWSIS was conducted by NREL and research partner General Electric (GE) in order to provide insight into the costs, technical or physical barriers, and operational impacts caused by the variability and uncertainty of wind, photovoltaic, and concentrated solar power when employed to serve up to 35% of the load energy in the WestConnect region (Arizona, Colorado, Nevada, New Mexico, and Wyoming). WestConnect is composed of several utility companies working collaboratively to assess stakeholder and market needs to and develop cost-effective improvements to the western wholesale electricity market. Participants include the Arizona Public Service, El Paso Electric Company, NV Energy, Public Service of New Mexico, Salt River Project, Tri-State Generation and Transmission Cooperative, Tucson Electric Power, Xcel Energy and the Western Area Power Administration.

  7. Use of isotopes for the study of pollutant behaviour in the unsaturated zone at three semi-arid sites in the USA

    International Nuclear Information System (INIS)

    As part of the International Atomic Energy Agency CRP on movement of pollutants through the unsaturated zone, three areas were examined in the United States. The three areas were: 1. A radioactive waste disposal site near Beatty Nevada. 2. The Upper Mojave Desert in Southern California. 3. The High Plains Aquifer (HPA) in the mid-continental area of the country. All sites were in arid to semi-arid locations with deep (>30 meters) unsaturated zones. Tritium results from all three sites indicate that recharge is focused and not an areal phenomena. Typically, in arid sites, ephemeral streams seem to be locations of focused recharge. It is also evident that lateral movement is an important part of movement of liquid, solutes, and gasses through the unsaturated zone. Models should be at least two dimensional to correctly represent this movement. The use of CFCs in the unsaturated zone can help in constructing these models. The studies in the HPA have shown that the onset of irrigation has mobilized naturally-occurring salts and moved them toward the water table. Due to the depth to the water table in the HPA, these salts have not yet entered the groundwater in most locations. At present, large quantities of both natural and agricultural chemicals are stored in the unsaturated zone and the potential exists for increased contamination from these chemicals in future years if this movement continues. In the case of the HPA, the switch from flood to sprinkler irrigation has slowed the movement of these contaminants. There is very little evidence of mitigation of agricultural contaminants below the root zone. Some reactions may occur at the saturated/unsaturated zone interface but it does not seem to have a major impact on chemical concentrations. (author)

  8. Managing soil moisture on waste burial sites in arid regions

    International Nuclear Information System (INIS)

    In semiarid regions, where potential evapotranspiration greatly exceeds precipitation, it is theoretically possible to preclude water form reaching interred wastes by (i) providing a sufficient cap of soil to store precipitation that falls while plants are dormant and (ii) establishing sufficient plant cover to deplete soil moisture during the growing season, thereby emptying the water storage reservoir of the soil. Here the authors discuss the theory and rationale for such an approach and then present the results of a field study to test its efficacy at the Idaho National Engineering Laboratory (INEL). They examined the capacity of four species of perennial plants to deplete soil moisture on simulated waste trenches and determined the effective water storage capacity of the soil. Those data enabled them to estimate the minimum depth of fill soil required to prevent deep drainage. Any of the species studied can use all of the plant-available soil water, even during a very wet growing season. The water storage capacity of the soil studied is 17% by volume, so a trench cap of 1.6 m of soil should be adequate to store precipitation received at the INEL while plants are dormant. They recommend a fill soil depth of 2 m to provide a margin of safety in case water accumulates in local areas as a result of heavy snow accumulation, subsidence, or runoff. Fill soil requirements and choice of plant species will vary, but the concepts and general approach are applicable to other shallow land burial sites in arid or semiarid regions. 23 refs., 5 figs

  9. 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.

  10. Assessing the Impact of Western Psychology in Hong Kong

    OpenAIRE

    Blowers, GH

    1991-01-01

    The impact of Western psychology in Hong Kong can be seen in its institutions and practices- Local students however acquire their knowledge of psychology through the medium of at least two foreign languages; English (the medium of instruction) and the technical language of its subject matter, which does not find ready equivalents in Chinese. Some examples of psychological terms in Chinese and English are presented to support this. Problems of translation and of the models implicit in much of ...

  11. Latent heat loss of dairy cows in an equatorial semi-arid environment

    Science.gov (United States)

    da Silva, Roberto Gomes; Maia, Alex Sandro Campos; de Macedo Costa, Leonardo Lelis; de Queiroz, João Paulo A. Fernandes

    2012-09-01

    The present study aimed to evaluate evaporative heat transfer of dairy cows bred in a hot semi-arid environment. Cutaneous ( E S) and respiratory ( E R) evaporation were measured (810 observations) in 177 purebred and crossbred Holstein cows from five herds located in the equatorial semi-arid region, and one herd in the subtropical region of Brazil. Rectal temperature ( T R), hair coat surface temperature ( T S) and respiratory rate ( F R) were also measured. Observations were made in the subtropical region from August to December, and in the semi-arid region from April to July. Measurements were done from 1100 to 1600 hours, after cows remained in a pen exposed to the sun. Environmental variables measured in the same locations as the animals were black globe temperature ( T G), air temperature ( T A), wind speed ( U), and partial air vapour pressure ( P V). Data were analysed by mixed models, using the least squares method. Results showed that average E S and E R were higher in the semi-arid region (117.2 W m-2 and 44.0 W m-2, respectively) than in the subtropical region (85.2 W m-2 and 30.2 W m-2, respectively). Herds and individual cows were significant effects ( P < 0.01) for all traits in the semi-arid region. Body parts did not affect T S and E S in the subtropical region, but was a significant effect ( P < 0.01) in the semi-arid region. The average flank T S (42.8°C) was higher than that of the neck and hindquarters (39.8°C and 41.6°C, respectively). Average E S was higher in the neck (133.3 W m-2) than in the flank (116.2 W m-2) and hindquarters (98.6 W m-2). Coat colour affected significantly both T S and E S ( P < 0.01). Black coats had higher T S and E S in the semi-arid region (41.7°C and 117.2 W m-2, respectively) than white coats (37.2°C and 106.7 W m-2, respectively). Rectal temperatures were almost the same in both subtropical and semi-arid regions. The results highlight the need for improved management methods specific for semi-arid regions.

  12. Western Hemisphere Knowledge Partnerships

    Science.gov (United States)

    Malone, T. F.

    2001-05-01

    , and application of knowledge concerning the nature of -- and interaction among -- matter, living organisms, energy, information, and human behavior. This strategy calls for innovative partnerships among the physical, biological, health, and social sciences, engineering, and the humanities. New kinds of partnership must also be forged among academia, business and industry, governments, and nongovernmental organizations. Geophysicists can play an important role in these partnerships. A focus for these partnerships is to manage the individual economic productivity that drives both human development and global change. As world population approaches stability during the twenty-first century, individual economic productivity will be the critical link between the human and the natural systems on planet Earth. AGU is among a core group of individuals and institutions proposing Western Hemisphere Knowledge Partnerships (WHKP) to test the hypothesis that knowledge, broadly construed, is an important organizing principle in choosing a path into the future. The WHKP agenda includes: (1) life-long learning, (2) the health and resilience of natural ecosystems, (3) eco-efficiency in economic production and consumption, (4) extension of national income accounts, (5) environmentally benign sources of energy, (6) delivery of health care, (7) intellectual property rights, and (8) networks for action by local communities.Collaboratories and distance education technologies will be major tools. A panel of experts will explore this proposal.

  13. Biocrust-forming mosses mitigate the negative impacts of increasing aridity on ecosystem multifunctionality in drylands.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T; Eldridge, David J; Bowker, Matthew A; Ochoa, Victoria; Gozalo, Beatriz; Berdugo, Miguel; Val, James; Singh, Brajesh K

    2016-03-01

    The increase in aridity predicted with climate change will have a negative impact on the multiple functions and services (multifunctionality) provided by dryland ecosystems worldwide. In these ecosystems, soil communities dominated by mosses, lichens and cyanobacteria (biocrusts) play a key role in supporting multifunctionality. However, whether biocrusts can buffer the negative impacts of aridity on important biogeochemical processes controlling carbon (C), nitrogen (N), and phosphorus (P) pools and fluxes remains largely unknown. Here, we conducted an empirical study, using samples from three continents (North America, Europe and Australia), to evaluate how the increase in aridity predicted by climate change will alter the capacity of biocrust-forming mosses to modulate multiple ecosystem processes related to C, N and P cycles. Compared with soil surfaces lacking biocrusts, biocrust-forming mosses enhanced multiple functions related to C, N and P cycling and storage in semiarid and arid, but not in humid and dry-subhumid, environments. Most importantly, we found that the relative positive effects of biocrust-forming mosses on multifunctionality compared with bare soil increased with increasing aridity. These results were mediated by plant cover and the positive effects exerted by biocrust-forming mosses on the abundance of soil bacteria and fungi. Our findings provide strong evidence that the maintenance of biocrusts is crucial to buffer negative effects of climate change on multifunctionality in global drylands. PMID:26452175

  14. Heavy metal contamination and source in arid agricultural soil in central Gansu Province, China

    Institute of Scientific and Technical Information of China (English)

    LI Yu; GOU Xin; WANG Gang; ZHANG Qiang; SU Qiong; XIAO Guoju

    2008-01-01

    Concentrations of copper (Cu), lead (Pb), chromium (Cr), mercury (Hg), and arsenic (As) were measured in arid agricultural and irrigated agricultural soils collected in Daba Village, Shajiawuan Village, Gangou Village and Sifangwu Village, located in central Gansu Province, China. Concentrations except Hg and Pb were lower than the background values in grey calcareous soil in the selected arid agricultural soils. Pb concentration exceeded the threshold of arid agricultural soils in China by 72. 46%. These results showed that there was indeed serious pollution with Pb, a slight pollution problem for other selected metals in the irrigated agricultural soils in Daba Village. Principal component analysis (PCA) was used to assess the soil data, applying varimax rotation with Kaiser Normalization. The result showed that the irrigated factor, agricultural factor and anthropogenic factor all contributed to the relations between selected chemical properties. The main factor of accumulation of Cu, Pb, Cr, Hg and As was lithological factor in arid agricultural areas. There is a striking dissimilarity of origin of Cu, Pb, Cr, Hg and As in agricultural soil between the irrigate agriculture and arid agriculture.

  15. 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 %5Cnodes%22 which can be left in the eld for many months. Embedded software would then increase sampling frequency during periods of rainfall. We hypothesized that this contrast between no-volume ow in karst passageways dur- ing dry periods and partial- or saturated-volume ow during a rain event is detectable by these Wireless Sensor Network (WSN) geophysical nodes, we call this a Wireless Resistivity Network (WRN). The development of new methodologies to characterize semi-arid karst hydrology is intended to augment Sandia National Laboratorys mission to lead e orts in energy technologies, waste disposal and climate security by helping to identify safe and secure regions and those that are at risk. Development and initial eld testing identi ed technological barriers to using WRNs for identifying semi-arid karst, exposing R&D which can be targeted in the future. Gravity, seismic, and resis- tivity surveys elucidated how each technique might e ectively be used to characterize semi-arid karst. This research brings to light the importance and challenges with char- acterizing semi-arid karst through a multi-method geophysical study. As there have been very few studies with this emphasis, this study has expanded the body of practical experience needed to protect the nations water and energy security interests.

  16. On the Role of Hyper-arid Regions within the Virtual Water Trade Network

    Science.gov (United States)

    Aggrey, James; Alshamsi, Aamena; Molini, Annalisa

    2016-04-01

    Climate change, economic development, and population growth are bound to increasingly impact global water resources, posing a significant threat to the sustainable development of arid regions, where water consumption highly exceeds the natural carrying capacity, population growth rate is high, and climate variability is going to impact both water consumption and availability. Virtual Water Trade (VWT) - i.e. the international trade network of water-intensive products - has been proposed as a possible solution to optimize the allocation of water resources on the global scale. By increasing food availability and lowering food prices it may in fact help the rapid development of water-scarce regions. The structure of the VWT network has been analyzed by a number of authors both in connection with trade policies, socioeconomic constrains and agricultural efficiency. However a systematic analysis of the structure and the dynamics of the VWT network conditional to aridity, climatic forcing and energy availability, is still missing. Our goal is hence to analyze the role of arid and hyper-arid regions within the VWN under diverse climatic, demographic, and energy constraints with an aim to contribute to the ongoing Energy-Water-Food nexus discussion. In particular, we focus on the hyper-arid lands of the Arabian Peninsula, the role they play in the global network and the assessment of their specific criticalities, as reflected in the VWN resilience.

  17. An Overview of the Semi-arid Climate and Environment Research Observatory over the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    HUANG Jianping; ZHANG Seidou; WANG Guoyin; FENG Guanghong; YUAN Jiuyi; ZHANG Lei; ZUO Hongchao; WANG Shigong; FU Congbin; CHOU Jifan; ZHANG Wu; ZUO Jinqing; BI Jianrong; SHI Jinsen; WANG Xin; CHANG Zhoulin; HUANG Zhongwei; YANG Su

    2008-01-01

    Arid and semi-arid areas comprise about 30% of the earth's surface. Changes in climate and climate variability will likely have a significant impact on these regions. The Loess Plateau over Northwest China is a special semi-arid land surface and part of a dust aerosol source. To improve understanding and capture the direct evidence of the impact of human activity on the semi-arid climate over the Loess Plateau, the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) was established in 2005. SACOL consists of a large set of instruments and focuses on: (1) monitoring of long term tendencies in semiarid climate changes; (2) monitoring of the aerosol effect on the water cycle; (3) studies of interaction between land surface and the atmosphere; (4) improving the land surface and climate models; and (5) validation of space-borne observations. This paper presents a description of SACOL objectives, measurements, and sampling strategies. Preliminary observation results are also reviewed in this paper.

  18. Spatial-Temporal Variation of Aridity Index of China during 1960–2013

    Directory of Open Access Journals (Sweden)

    Huiping Huang

    2016-01-01

    Full Text Available Aridity index, as the ration of potential evapotranspiration and precipitation, is an important indicator of regional climate. GIS technology, Morlet wavelet, Mann-Kendall test, and principal component analysis are utilized to investigate the spatial-temporal variation of aridity index and its impacting factors in China on basis of climate data from 599 stations during 1960–2013. Results show the following. (1 Boundaries between humid and semihumid region, and semihumid and semiarid region coincide with 400 mm and 800 mm precipitation contour lines. (2 Average annual aridity index is between 3.4 and 7.5 and shows decrease trend with a tendency of –0.236 per decade at 99% confidence level. (3 The driest and wettest month appear in December and July, respectively, in one year. (4 Periods of longitudinal and latitudinal shift of aridity index 1, 1.5, and 4 contours coordinate are 10 and 25 years, 6 and 26 years, and 5 and 25 years, respectively. (5 Four principal components which affect aridity index are thermodynamic factors, water and radiation factors, geographical and air dynamic factors, and evaluation factor, respectively.

  19. Western Pacific Air-Sea Interaction Study (W-PASS), Introduction and Highlights (Invited)

    Science.gov (United States)

    Tsuda, A.

    2010-12-01

    Western Pacific Air-Sea Interaction Study (W-PASS), Introduction and Highlights Atsushi Tsuda Atmosphere and Ocean Research Institute, The University of Tokyo In the western Pacific (WESTPAC) region, dust originating from Asian and Australian arid regions to the North and South Pacific, biomass burning emissions from the Southeast Asia to sub-tropical Pacific, and other anthropogenic substances are transported regionally and globally to affect cloud and rainfall patterns, air quality, and radiative budgets downwind. Deposition of these compounds into the Asian marginal seas and onto the Pacific Ocean influence surface primary productivity and species composition. In the WESTPAC region, subarctic, subtropical oceans and marginal seas are located relatively narrow latitudinal range and these areas are influenced by the dust and anthropogenic inputs. Moreover, anthropogenic emission areas are located between the arid region and the oceans. The W-PASS (Western Pacific Air-Sea interaction Study) project has been funded for 5 years as a part of SOLAS-Japan activity in the summer of 2006. We aim to resolve air-sea interaction through field observation studies mainly using research vessels and island observatories over the western Pacific. We have carried out 5 cruises to the western North Pacific focusing on air-sea interactions. Also, an intensive marine atmospheric observation including direct atmospheric deposition measurement was accomplished by a dozen W-PASS research groups at the NIES Atmospheric and Aerosol Monitoring Station of Cape Hedo in the northernmost tip of the Okinawa main Island facing the East China Sea in the spring 2008. A few weak Kosa (dust) events, anthropogenic air outflows, typical local air and occupation of marine background air were identified during the campaign period. The W-PASS has four research groups mainly focusing on VOC emissions, air-sea gas exchange processes, biogeochemical responses to dust depositions and its modeling. We also

  20. Evidence of moisture control on the methylation of branched glycerol dialkyl glycerol tetraethers in semi-arid and arid soils

    Science.gov (United States)

    Dang, Xinyue; Yang, Huan; Naafs, B. David A.; Pancost, Richard D.; Xie, Shucheng

    2016-09-01

    The distribution of bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs) is influenced by growth temperature and pH. This results in the widespread application of the brGDGT-based MBT(‧)/CBT proxy (MBT - methylation of branched tetraethers, CBT - cyclization of branched tetraethers) in terrestrial paleo-environmental reconstructions. Recently, it was shown that the amount of precipitation could also have an impact on CBT, as well as the abundance of brGDGTs relative to that of archaeal isoprenoidal (iso)GDGTs (Ri/b) and the absolute abundance of brGDGTs, potentially complicating the use of MBT/CBT as paleothermometer. However, the full influence of hydrology, and in particular soil water content (SWC), on GDGT distributions remains unclear. Here we investigated variations in the GDGT distribution across a SWC gradient (0-61%) around Qinghai Lake in the Tibetan Plateau, an arid to semiarid region in China. Our results demonstrate that SWC affects the brGDGT distribution. In particular, we show that SWC has a clear impact on the degree of methylation of C6-methylated brGDGTs, whereas C5-methylated brGDGTs are more impacted by temperature. This results in a combined SWC and temperature control on MBT‧. In this context we propose a diagnostic parameter, the IR6ME (relative abundance of C6-methylated GDGTs) index, to evaluate the applicability of brGDGT-based paleotemperature reconstructions. Using the global dataset, expanded with our own data, MBT‧ has a significant correlation with mean annual air temperature when IR6ME precipitation (i.e., a substantial reflection of SWC impact) when IR6ME > 0.5, implying that MBT‧ may respond to hydrological change in these regions and can be used as a proxy for MAP.

  1. Revegetation Plan for Areas of the Fitzner-Eberhardt Arid Lands Ecology Reserve Affected by Decommissioning of Buildings and Infrastructure and Debris Clean-up Actions

    Energy Technology Data Exchange (ETDEWEB)

    Downs, Janelle L.; Durham, Robin E.; Larson, Kyle B.

    2011-01-01

    The U.S. Department of Energy (DOE), Richland Operations Office is working to remove a number of facilities on the Fitzner Eberhardt Arid Lands Ecology Reserve (ALE), which is part of the Hanford Reach National Monument. Decommissioning and removal of buildings and debris on ALE will leave bare soils and excavated areas that need to be revegetated to prevent erosion and weed invasion. Four main areas within ALE are affected by these activities (DOE 2009;DOE/EA-1660F): 1) facilities along the ridgeline of Rattlesnake Mountain, 2) the former Nike missile base and ALE HQ laboratory buildings, 3) the aquatic research laboratory at Rattlesnake Springs area, and 4) a number of small sites across ALE where various types of debris remain from previous uses. This revegetation plan addresses the revegetation and restoration of those land areas disturbed by decommissioning and removal of buildings, facilities and associated infrastructure or debris removal. The primary objective of the revegetation efforts on ALE is to establish native vegetation at each of the sites that will enhance and accelerate the recovery of the native plant community that naturally persists at that location. Revegetation is intended to meet the direction specified by the Environmental Assessment (DOE 2009; DOE/EA-1660F) and by Stipulation C.7 of the Memorandum of Agreement (MOA) for the Rattlesnake Mountain Combined Community Communication Facility and InfrastructureCleanup on the Fitzner/Eberhardt Arid Lands Ecology Reserve, Hanford Site, Richland Washington(DOE 2009; Appendix B). Pacific Northwest National Laboratory (PNNL) under contract with CH2M Hill Plateau Remediation Company (CPRC) and in consultation with the tribes and DOE-RL developed a site-specific strategy for each of the revegetation units identified within this document. The strategy and implementation approach for each revegetation unit identifies an appropriate native species mix and outlines the necessary site preparation activities

  2. 76 FR 1429 - Loveland Area Projects/Western Area Colorado Missouri Balancing Authority-Rate Order No. WAPA-154

    Science.gov (United States)

    2011-01-10

    ... Area Power Administration Loveland Area Projects/Western Area Colorado Missouri Balancing Authority--Rate Order No. WAPA-154 AGENCY: Western Area Power Administration, DOE. ACTION: Notice of Rate Order... through February 28, 2011. 73 FR 48382, August 19, 2008. \\3\\ WAPA-118 was approved by FERC on a...

  3. Water balance of two earthen landfill caps in a semi-arid climate

    Energy Technology Data Exchange (ETDEWEB)

    Khire, M.V. [GeoSyntec Consultants, Boca Raton, FL (United States); Benson, C.H.; Bosscher, P.J. [Univ. of Wisconsin, Madison, WI (United States)

    1997-12-31

    Water balance data are presented that were obtained from two earthen cap test sections located in a semi-arid region. The test sections were constructed on a municipal solid waste landfill in East Wenatchee, Washington, USA. One test section represents a traditional resistive barrier, and is constructed with a compacted silty clay barrier 60 cm thick and a vegetated silty clay surface layer 15 cm thick. The other test section represents a capillary barrier and has a sand layer 75 cm thick overlain by a 15-cm-thick vegetated surface layer of silt. Extensive hydrological and meteorological data have been collected since November 1992. Unsaturated hydraulic properties of soils, hydrologic parameters, and vegetation have been extensively characterized. Results of the study show that capillary barriers can be effective caps in semi-arid and arid regions. They are also cheaper to construct and can perform better than traditional resistive barriers.

  4. Landscaping and performance of some aesthetic plant species in hot,arid conditions of India

    Institute of Scientific and Technical Information of China (English)

    Rajesh Kumar Gupta; Pradeep Chaudhry; Rameshwar Lal Srivastava

    2012-01-01

    Abstract:Establishment of ornamental and aesthetic plants in hot,arid conditions of India is difficult due to the prevailing climatic,edaphic and biotic factors.Effect of turfgrass on the growth of ornamental plants in hot arid conditions has not been studied so far anywhere in the world.A study was conducted on the campus of Arid Forest Research Institute,Jodhpur,India to assess the performance of a few ornamental plant species in combination with turfgrass and without turfgrass with respect to different soil tilling intervals.Growth of plants was better with turfgrass than without turfgrass.We suggest adopting a soil tilling interval of 30 days to achieve optimum growth of ornamental plant species in terms of height and crown diameter.Our results can help reduce labor costs and achieving better landscapes in fewer days in hot urban conditions of Indian sub continent.

  5. REUSE OF TREATED WASTEWATER IN AGRICULTURE: SOLVING WATER DEFICIT PROBLEMS IN ARID AREAS (REVIEW

    Directory of Open Access Journals (Sweden)

    Faissal AZIZ

    2014-12-01

    Full Text Available 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. In this context, the present work is a review focusing the reuse of treated wastewater in agriculture as an important strategy for solving water deficit problems in arid areas. Much information concerning the wastewater reuse in different regions of the world and in Morocco, the different wastewater treatment technologies existing in Morocco were discussed. The review focused also the fertilizing potential of wastewater in agriculture, the role of nutrients and their concentrations in wastewater and their advantages effects on plant growth and yield.

  6. A multiscale, hierarchical model of pulse dynamics in arid-land ecosystems

    Science.gov (United States)

    Collins, Scott L.; Belnap, Jayne; Grimm, N. B.; Rudgers, J. A.; Dahm, C. N.; D'Odorico, P.; Litvak, M.; Natvig, D. O.; Peters, Douglas C.; Pockman, W. T.; Sinsabaugh, R. L.; Wolf, B. O.

    2014-01-01

    Ecological processes in arid lands are often described by the pulse-reserve paradigm, in which rain events drive biological activity until moisture is depleted, leaving a reserve. This paradigm is frequently applied to processes stimulated by one or a few precipitation events within a growing season. Here we expand the original framework in time and space and include other pulses that interact with rainfall. This new hierarchical pulse-dynamics framework integrates space and time through pulse-driven exchanges, interactions, transitions, and transfers that occur across individual to multiple pulses extending from micro to watershed scales. Climate change will likely alter the size, frequency, and intensity of precipitation pulses in the future, and arid-land ecosystems are known to be highly sensitive to climate variability. Thus, a more comprehensive understanding of arid-land pulse dynamics is needed to determine how these ecosystems will respond to, and be shaped by, increased climate variability.

  7. Metagenomic characterization of biodiversity in the extremely arid desert soils of Kazakhstan

    Science.gov (United States)

    Kutovaya, O. V.; Lebedeva, M. P.; Tkhakakhova, A. K.; Ivanova, E. A.; Andronov, E. E.

    2015-05-01

    For the first time, the composition of microbiomes in the biological crust (AKL) horizons of extremely arid desert soils (Aridic Calcisols) developed from saline and nonsaline alluvial deposits in the Ili Depression (eastern Kazakhstan) was analyzed. To describe the diversity of microorganisms in the soil samples, a novel method of pyrosequencing (Roche/454 Life Sciences) was applied. It was shown that bacteria from the Proteobacteria, Actinobacteria, Firmicutes, Verrucomicrobia, Acidobacteria, and Bacteroidetes phyla predominate in all the samples; these are typical representatives of the microbiome of soil crusts. A distinctive feature of the extremely arid soils is the high contribution of cyanobacteria (25-30%) to the total DNA. In the soils developed from saline sediments, representatives from the Rubrobacteraceae, Streptococcaceae, and Caulobacteraceae families and from the Firmicutes phylum predominated. In the soils developed from nonsaline gypsiferous deposits, bacteria from the class of Acidobacteria, subgroup Gp3, of the Methylobacteriaceae family and the class of Subdivision 3 from the Verrucomicrobia phylum predominated.

  8. Large-scale hydrological modelling in the semi-arid north-east of Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Guentner, A.

    2002-09-01

    Semi-arid areas are characterized by small water resources. An increasing water demand due to population growth and economic development as well as a possible decreasing water availability in the course of climate change may aggravate water scarcity in future in these areas. The quantitative assessment of the water resources is a prerequisite for the development of sustainable measures of water management. For this task, hydrological models within a dynamic integrated framework are indispensable tools. The main objective of this study is to develop a hydrological model for the quantification of water availability over a large geographic domain of semi-arid environments. The study area is the Federal State of Ceara in the semi-arid north-east of Brazil. Surface water from reservoirs provides the largest part of water supply. The area has recurrently been affected by droughts which caused serious economic losses and social impacts like migration from the rural regions. (orig.)

  9. Biology and invasive species in the western U.S

    Science.gov (United States)

    U.S. Geological Survey

    2005-01-01

    The diversity of environments that characterizes the West is responsible for the region's rich biological heritage. This ecological diversity also means that opportunities for invasive species are many, varied, and complex. Island ecosystems are notoriously vulnerable to invaders as demonstrated in Hawaii and West Coast offshore islands. Aquatic invaders impose high economic and environmental costs in systems as varied as San Francisco Bay and desert springs in the Great Basin. Although the West's arid and montane ecosystems may seem resistant to plant and animal invaders, we now know that ex-otic species have altered physical processes related to fire and hydrology in a manner favoring further expansion and persis-tence of invaders. Natural resource managers value analytical, mapping, and genetics tools developed by USGS scientists to monitor invasive species and help conserve biological systems. USGS biologists conduct research to assist land and water managers' efforts to control invasive species and restore natural systems. Throughout the West, the USGS carries out studies for early detection and rapid assessment of invaders. The following are some examples of how the USGS is making a difference in the western United States.

  10. On predicting debris flows in arid mountain belts

    Science.gov (United States)

    Stolle, Amelie; Langer, Maria; Blöthe, Jan Henrik; Korup, Oliver

    2015-03-01

    The use of topographic metrics for estimating the susceptibility to, and reconstructing the characteristics of, debris flows has a long research tradition, although largely devoted to humid mountainous terrain. The exceptional 2010 monsoonal rainstorms in the high-altitude mountain desert of Ladakh and Zanskar, NW India, were a painful reminder of how susceptible arid regions are to rainfall-triggered flash floods, landslides, and debris flows. The rainstorms of August 4-6 triggered numerous debris flows, killing 182 people, devastating 607 houses, and more than 10 bridges around Ladakh's capital of Leh. The lessons from this disaster motivated us to revisit methods of predicting (a) flow parameters such as peak discharge and maximum velocity from field and remote sensing data, and (b) the susceptibility to debris flows from catchment morphometry. We focus on quantifying uncertainties tied to these approaches. Comparison of high-resolution satellite images pre- and post-dating the 2010 rainstorm reveals the extent of damage and catastrophic channel widening. Computations based on these geomorphic markers indicate maximum flow velocities of 1.6-6.7 m s- 1 with runout of up to ~ 10 km on several alluvial fans that sustain most of the region's settlements. We estimate median peak discharges of 310-610 m3 s- 1, which are largely consistent with previous estimates. Monte Carlo-based error propagation for a single given flow-reconstruction method returns a variance in discharge similar to one derived from juxtaposing several different flow reconstruction methods. We further compare discriminant analysis, classification tree modelling, and Bayesian logistic regression to predict debris-flow susceptibility from morphometric variables of 171 catchments in the Ladakh Range. These methods distinguish between fluvial and debris flow-prone catchments at similar success rates, but Bayesian logistic regression allows quantifying uncertainties and relationships between potential

  11. Contaminants at DOE sites and their susceptibility to bioremediation

    International Nuclear Information System (INIS)

    Contaminants at DOE sites encompass a range of common industrial pollutants. However, the prevalence of contaminant mixtures including organics, metals, and radionuclides is relatively unique to DOE's facilities. Bioremediation has been shown to be effective for destruction of many of the organic pollutants. The technology also has promise for application to many of the metals and radionuclides; however, field demonstrations for these applications have not yet been attempted. Because of the complexity of biodegradation of even a single-compound class, little has been done to develop or demonstrate in situ bioremediation technologies for multicompound combinations. The current bioremediation demonstration on CCl4 and nitrates within the VOC-Arid Integrated Demonstration is one the first efforts to address inorganic and organic co-contaminants simultaneously. Additional research, technology development, and field demonstrations are needed to evaluate the applicability of in situ bioremediation to DOE's most common contaminant mixtures

  12. Great Basin semi-arid woodland dynamics during the late quaternary

    Energy Technology Data Exchange (ETDEWEB)

    Wigand, P.E.; Hemphill, M.L.; Sharpe, S.E. [Univ. and Community College System of Nevada, Reno, NV (United States)] [and others

    1995-09-01

    Semi-arid woodlands have dominated the middle elevations of Great Basin mountain ranges during the Holocene where subalpine woodlands prevailed during the Pleistocene. Ancient woodrat middens, and in a few cases pollen records indicate in the late Pleistocene and early Holocene woodland history lowered elevation of subalpine woodland species. After a middle Holocene retrenchment at elevations in excess of 500 meters above today, Juniper-dominated semi-arid woodland reached its late Holocene maximum areal extent during the Neoglacial (2 to 4 ka). These records, along with others indicate contracting semi-arid woodland after the Neoglacial about 1.9 ka. Desert shrub community expansion coupled with increased precariousness of wetland areas in the southern Great Basin between 1.9 and 1.5 ka coincide with shrinking wet-lands in the west-central and northern Great Basin. Coincident greater grass abundance in northern Great Basin sagebrush steppe, reaching its maximum between 1.5 and 1.2 ka, corresponds to dramatic increases in bison remains in the archaeological sites of the northern Intermontane West. Pollen and woodrat midden records indicate that this drought ended about 1.5 ka. Succeeding ameliorating conditions resulted in the sudden northward and downward expansion of pinon into areas that had been dominated by juniper during the Neoglacial. Maximum areal extent of pinon dominated semi-arid woodland in west-central Nevada was centered at 1.2 ka. This followed by 100 years the shift in dominance from juniper to pinon in southern Nevada semi-arid woodlands. Great Basin woodlands suffered from renewed severe droughts between .5 to .6 ka. Effectively wetter conditions during the {open_quotes}Little Ice Age{close_quotes} resulted in re-expansion of semi-arid woodland. Activities related to European settlement in the Great Basin have modified prehistoric factors or imposed new ones that are affecting woodland response to climate.

  13. An Overview of Biodegradation of LNAPLs in Coastal (Semi)-arid Environment.

    Science.gov (United States)

    Yadav, Brijesh Kumar; Hassanizadeh, S Majid

    2011-09-01

    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 organic contaminated resources is receiving increasing interests and where applicable, can serve as a cost-effective remediation alternative. The success of bioremediation greatly depends on the prevailing environmental variables, and their remediation favoring customization requires a sound understanding of their integrated behavior on fate and transport of LNAPLs under site-specific conditions. The arid and semi-arid coastal sites are characterized by specific environmental extremes; primarily, varying low and high temperatures, high salinity, water table dynamics, and fluctuating soil moisture content. An understanding of the behavior of these environmental variables on biological interactions with LNAPLs would be helpful in customizing the bioremediation for restoring problematic sites in these regions. Therefore, this paper reviews the microbial degradation of LNAPLs in soil-water, considering the influences of prevailing environmental parameters of arid and semi-arid coastal regions. First, the mechanism of biodegradation of LNAPLs is discussed briefly, followed by a summary of popular kinetic models used by researchers for describing the degradation rate of these hydrocarbons. Next, the impact of soil moisture content, water table dynamics, and soil-water temperature on the fate and transport of LNAPLs are discussed, including an overview of the studies conducted so far. Finally, based on the reviewed information, a general conclusion is presented with recommendations for future research subjects on optimizing the bioremediation technique in the field under the aforesaid environmental conditions. The present review will be useful to better understand the

  14. An Overview of Biodegradation of LNAPLs in Coastal (Semi)-arid Environment.

    KAUST Repository

    Yadav, Brijesh Kumar

    2011-02-22

    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 organic contaminated resources is receiving increasing interests and where applicable, can serve as a cost-effective remediation alternative. The success of bioremediation greatly depends on the prevailing environmental variables, and their remediation favoring customization requires a sound understanding of their integrated behavior on fate and transport of LNAPLs under site-specific conditions. The arid and semi-arid coastal sites are characterized by specific environmental extremes; primarily, varying low and high temperatures, high salinity, water table dynamics, and fluctuating soil moisture content. An understanding of the behavior of these environmental variables on biological interactions with LNAPLs would be helpful in customizing the bioremediation for restoring problematic sites in these regions. Therefore, this paper reviews the microbial degradation of LNAPLs in soil-water, considering the influences of prevailing environmental parameters of arid and semi-arid coastal regions. First, the mechanism of biodegradation of LNAPLs is discussed briefly, followed by a summary of popular kinetic models used by researchers for describing the degradation rate of these hydrocarbons. Next, the impact of soil moisture content, water table dynamics, and soil-water temperature on the fate and transport of LNAPLs are discussed, including an overview of the studies conducted so far. Finally, based on the reviewed information, a general conclusion is presented with recommendations for future research subjects on optimizing the bioremediation technique in the field under the aforesaid environmental conditions. The present review will be useful to better understand the

  15. 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.

  16. Theoretical critical value curve and driving force formation of ecological migration in the arid land

    Institute of Scientific and Technical Information of China (English)

    ZHU Zi'an; ZHANG Xiaolei

    2006-01-01

    The features of the fragile eco-environment of the arid land decide that its capacity of disturbance-resistance is lower. The natural desert oases in the arid land are in mosaic patches distributed in a wide Gobi desert. The population distribution is greatly dependent on water resources. The population is characterized with dispersed distribution, simple production and living style, and poverty and remoteness. The reason why the ecological migrations are carried out lies in the ecological problems. "Ecological degradation" is the main driving force of the ecological migration. Then, the strength of the driving force depends on the degree of ecological degradation. Hence, whether to carry out ecological migration depends on the extent of ecological degradation.Theoretically, the critical value curve for calculating ecological migration in the arid land is put forward through comprehensive research of relative problems of ecology, economics etc., combined with the ecological migration experience in the arid land, and based on the features of the arid environment. In this article, with this curve, the theoretical research and some practice of the ecological migration have been done from the perspective of natural behavior and governmental behavior of the driving force formation of ecological migration. It analyses the active driving force (factors) and negative forces (factors), and points out the timing and steps of implementing the ecological migration in the arid land. The theoretical curve embodies certain originality and applicability,which provides a quantitative method for evaluating 196the degree of ecological degradation and the theoretical base for implementing ecological migration projects.

  17. Plant functional traits and phylogenetic relatedness explain variation in associations with root fungal endophytes in an extreme arid environment

    Science.gov (United States)

    Since root endophytes may ameliorate drought stress, understanding which plants associate with endophytes is important, especially in arid ecosystems. Here we characterized the root endophytes of 42 plants from an arid region of Argentina. We related colonization by arbuscular mycorrhizal fungi (AMF...

  18. Oviposition-site selection by Phyllomedusa sauvagii (Anura: Hylidae): An arboreal nester inhabiting arid environments

    Science.gov (United States)

    García, Cecilia G.; Lescano, Julián N.; Leynaud, Gerardo C.

    2013-08-01

    Breeding biology in Phyllomedusa sauvagii is related to vegetation since the species encloses its eggs in leaves above water. Considering that arid environments may represent high risks of death by desiccation for amphibians with this reproductive mode, we evaluated plant characteristics associated with sites used for oviposition in semi-permanent ponds in the Arid Chaco region of Argentina. Plant characteristics were used to fit a statistical habitat selection model that allows the prediction of nest presence. Our results show that P. sauvagii needs substrate with specific features for oviposition that would help to reduce the probability of eggs and tadpoles desiccation.

  19. New crops for arid lands. [Bladderpod, gumweed, guayule, jojoba, and buffalo gourd

    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 or 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. 20 references.

  20. The Exploration of Mars and the Improvement of Living Conditions in Western Asian Countries

    Science.gov (United States)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    Space is the new frontier. The exploration of a new world, Mars, has been giving people on Earth valuable comparative information about climatic and geological processes occurring here on our home planet. With the Viking 1 and 2, Mars Global Surveyor, Mars Odyssey, Mars Reconnaissance Orbiter, Sojourner, Spirit, Opportunity, Curiosity, etc., spacecrafts, which explored the Red Planet we obtained a great deal information about the extremely arid soil and dry air of Mars in the present, and its watery condition in the distant past. Now there is a decade-long, program of robotic exploration of the martian atmosphere and soil - the 'Mars Surveyor Program', which is a series of small, cheap and fast spacecrafts, carrying very few scientific instruments, to be launched about every two years. Here in this paper, under the principles in the United Nations' Agenda 21, we comment on this new phase of Mars exploration under development, which began in 1996, and its benefits to living conditions in developing countries with desert regions. A peaceful regular research of the arid Mars, will help us to understand much better the dynamics of formation of dry regions here on Earth. We suggest that, if the developing countries participate in that program, they will achieve the scientific understanding to create a practical technology, with which they will acquire ways to future transform their arid areas into a more humid places, and to slow the process of desertification of other regions. This, using their own natural resources and own scientific personnel. That would strongly benefit the living conditions in Western Asian countries, which have many desert regions.

  1. Remotely-Sensed Regional-Scale Evapotranspiration of a Semi-Arid Great Basin Desert and its Relationship to Geomorphology, Soils, and Vegetation

    Science.gov (United States)

    Laymon, C.; Quattrochi, D.; Malek, E.; Hipps, L.; Boettinger, J.; McCurdy, G.

    1998-01-01

    Landsat thematic mapper data are used to estimate instantaneous regional-scale surface water and energy fluxes in a semi-arid Great Basin desert of the western United States. Results suggest that it is possible to scale from point measurements of environmental state variables to regional estimates of water and energy exchange. This research characterizes the unifying thread in the classical climate-topography-soil-vegetation relation -the surface water and energy balance-through maps of the partitioning of energy throughout the landscape. The study was conducted in Goshute Valley of northeastern Nevada, which is characteristic of most faulted graben valleys of the Basin and Range Province of the western United States. The valley comprises a central playa and lake plain bordered by alluvial fans emanating from the surrounding mountains. The distribution of evapotranspiration (ET) is lowest in the middle reaches of the fans where the water table is deep and plants are small, resulting in low evaporation and transpiration. Highest ET occurs in the center of the valley, particularly in the playa, where limited to no vegetation occurs, but evaporation is relatively high because of a shallow water table and silty clay soil capable of large capillary movement. Intermediate values of ET are associated with large shrubs and is dominated by transpiration.

  2. Comparison of satellite microwave backscattering (ASCAT and visible/near-infrared reflectances (PARASOL for the estimation of aeolian aerodynamic roughness length in arid and semi-arid regions

    Directory of Open Access Journals (Sweden)

    C. Prigent

    2012-04-01

    Full Text Available Previous studies examined the possibility to estimate the aeolian aerodynamic roughness length from satellites, either from visible/near-infrared observations or from microwave backscattering measurements. Here we compare the potential of the two approaches and propose to merge the two sources of information to benefit from their complementary aspects, i.e. the high spatial resolution of the visible/near-infrared (PARASOL part of the A-Train and the independence from atmospheric contamination of the active microwaves (ASCAT on board MetOp. A global map of the aeolian aerodynamic roughness length at 6 km resolution is derived, for arid and semi-arid regions. It shows very good consistency with the existing information on the properties of these surfaces. The dataset is available to the community, for use in atmospheric dust transport models.

  3. Comparison of satellite microwave backscattering (ASCAT and visible/near-infrared reflectances (PARASOL for the estimation of aeolian aerodynamic roughness length in arid and semi-arid regions

    Directory of Open Access Journals (Sweden)

    C. Prigent

    2012-11-01

    Full Text Available Previous studies examined the possibility to estimate the aeolian aerodynamic roughness length from satellites, either from visible/near-infrared observations or from microwave backscattering measurements. Here we compare the potential of the two approaches and propose to merge the two sources of information to benefit from their complementary aspects, i.e. the high spatial resolution of the visible/near-infrared (6 km for PARASOL that is part of the A-Train and the independence from atmospheric contamination of the active microwaves (ASCAT on board MetOp with a lower spatial resolution of 25 km. A global map of the aeolian aerodynamic roughness length at 6 km resolution is derived, for arid and semi-arid regions. It shows very good consistency with the existing information on the properties of these surfaces. The dataset is available to the community, for use in atmospheric dust transport models.

  4. Impacts of Present and Future Climate Variability and Change on Agriculture and Forestry in the Arid and Semi-Arid Tropics

    International Nuclear Information System (INIS)

    The arid and semi-arid regions account for approximately 30% of the world total area and are inhabited by approximately 20% of the total world population. Issues of present and future climate variability and change on agriculture and forestry in the arid and semi-arid tropics of the world were examined and discussion under each of these issues had been presented separately for Asia, Africa and Latin America. Several countries in tropical Asia have reported increasing surface temperature trends in recent decades. Although, there is no definite trend discernible in the long-term mean for precipitation for the tropical Asian region, many countries have shown a decreasing trend in rainfall in the past three decades. African rainfall has changed substantially over the last 60 yr and a number of theoretical, modelling and empirical analyses have suggested that noticeable changes in the frequency and intensity of extreme events, including floods may occur when there are only small changes in climate. Climate in Latin America is affected by the El Nino-southern oscillation (ENSO) phases and there is a close relationship between the increase and decrease of rainfall depending upon the warm or cold phases of the phenomenon. Over land regions of Asia, the projected area-averaged annual mean warming is likely to be 1.6 ± 0.2C in the 2020s, 3.1 ± 0.3C in the 2050s, and 4.6 ± 0.4C in the 2080s and the models show high uncertainty in projections of future winter and summer precipitation. Future annual warming across Africa is projected to range from 0.2C per decade to more than 0.5C per decade, while future changes in mean seasonal rainfall in Africa are less well defined. In Latin America, projections indicate a slight increase in temperature and changes in precipitation. Impacts of climate variability and changes are discussed with suitable examples. Agricultural productivity in tropical Asia is sensitive not only to temperature increases, but also to changes in the nature

  5. Western Canada Sedimentary Basin competitiveness

    International Nuclear Information System (INIS)

    Recent dramatic expansion of the natural gas industry in the Western Canada Sedimentary Basin provided ample proof of the potential of this area for further development of natural gas supply. However, the inherent competitive advantages provided by the Western Canada Sedimentary Basin were said to have been offset by low netback prices resulting in poor producer economics when competitiveness is measured by availability of opportunities to find and develop gas supply at costs low enough to ensure attractive returns. Technology was identified as one of the key elements in improving basin competitiveness, but the greatest potential lies in reduced transportation costs and increased access to North American market centres. 8 figs

  6. Renewable energy and sustainable urban development in hot arid regions - case of Egypt : development concepts and implementation strategies for new settlements

    OpenAIRE

    Abd-Elaal; Mohammad Refaat Mohammad

    2008-01-01

    The main objective of this research is to make a connection between the hot arid regions urban development and renewable energy e.g. photovoltaics (PV), to delineate urban integrated renewable energy e.g. Urban Integrated Photovoltaics (UIPV) as a new approach for building new sustainable settlements in hot arid regions. The study assumes that applying this approach can play a major role in developing communities of the hot arid regions. Furthermore, the study claimed that developing arid re...

  7. Drought-tolerant Streptomyces pactum Act12 assist phytoremediation of cadmium-contaminated soil by Amaranthus hypochondriacus: great potential application in arid/semi-arid areas.

    Science.gov (United States)

    Cao, Shumiao; Wang, Wenke; Wang, Fei; Zhang, Jun; Wang, Zhoufeng; Yang, Shenke; Xue, Quanhong

    2016-08-01

    Microbe-assisted phytoremediation provides an effective approach to clean up heavy metal-contaminated soils. However, severe drought may affect the function of microbes in arid/semi-arid areas. Streptomyces pactum Act12 is a drought-tolerant soil actinomycete strain isolated from an extreme environment on the Qinghai-Tibet Plateau, China. In this study, pot experiments were conducted to assess the effect of Act12 on Cd tolerance, uptake, and accumulation in amaranth (Amaranthus hypochondriacus) under water deficit. Inoculated plants had higher Cd concentrations (root 8.7-33.9 %; shoot 53.2-102.1 %) and uptake (root 19.9-95.3 %; shoot 110.6-170.1 %) than non-inoculated controls in Cd-treated soil. The translocation factor of Cd from roots to shoots was increased by 14.2-75 % in inoculated plants, while the bioconcentration factor of Cd in roots and shoots was increased by 10.2-64.4 and 53.9-114.8 %, respectively. Moreover, inoculation with Act12 increased plant height, root length, and shoot biomass of amaranth in Cd-treated soil compared to non-inoculated controls. Physiochemical analysis revealed that Act12 enhanced Cd tolerance in the plants by increasing glutathione, elevating superoxide dismutase and catalase activities, as well as reducing malondialdehyde content in the leaves. The drought-tolerant actinomycete strain Act12 can enhance the phytoremediation efficiency of amaranth for Cd-contaminated soils under water deficit, exhibiting potential for application in arid and semi-arid areas. PMID:27072036

  8. ESTIMATION OF EXTRACELLULAR LIPOLYTIC ENZYME ACTIVITY BY THERMOPHILIC BACILLUS SP. ISOLATED FROM ARID AND SEMI-ARID REGION OF RAJASTHAN, INDIA

    Directory of Open Access Journals (Sweden)

    Deeksha Gaur

    2012-10-01

    Full Text Available Thermophilic organisms can be defined as, micro-organisms which are adapted to survive at high temperatures. The enzymes secreted by thermophilic bacteria are capable of catalyzing biochemical reactions at high temperatures. Thermophilic bacteria are able to produce thermostable lipolytic enzymes (capable of degradation of lipid at temperatures higher than mesophilic bacteria. Therefore, the isolation of thermophilic bacteria from natural sources and their identification are quite beneficial in terms of discovering thermostable lipase enzymes. Due to great temperature fluctuation in hot arid and semi-arid region of Rajasthan, this area could serve as a good source for new thermophilic lipase producing bacteria with novel industrially important properties. The main objective of this research is the isolation and estimation of industrially important thermophilic lipase enzyme produced by thermophilic bacteria, isolated from arid and semi-arid region of Rajasthan. For this research purpose soil samples were collected from Churu, Sikar and Jhunjunu regions of Rajasthan. Total 16 bacterial strains were isolated and among only 2 thermostable lipolytic enzyme producing bacteria were charcterized. The thermostable lipolytic enzyme was estimated by qualitative and quantitative experiments. The isolates were identified as Bacillus sp. by microscopic, biochemical and molecular characterization. The optimum enzyme activity was observed at pH 8, temperature 60°C and 6% salt concentrations at 24 hrs time duration. Lipolytic enzyme find useful in a variety of biotechnological fields such as food and dairy (cheese ripening, flavour development, detergent, pharmaceutical (naproxen, ibuprofen, agrochemical (insecticide, pesticide and oleochemical (fat and oil hydrolysis, biosurfactant synthesis industries. Lipolytic enzyme can be further used in many newer areas where they can serve as potential biocatalysts.

  9. Paradoxes of western energy development: how can we maintain the land and the people if we develop

    Energy Technology Data Exchange (ETDEWEB)

    McKell, C.M.; Browne, D.G.; Cruze, E.C.; Freudenburg, W.R.; Perrine, R.L.; Roach, F. (eds.)

    1984-01-01

    The 27 authors of this book evaluate western energy resources, then discuss the consequences of development on the region's physical and social environments. Among the questions they consider are the distribution of environmental costs and economic benefits of development; the effects on the environment, the social structure, and the quality of life; whether open spaces should be regarded as a national treasure in their present form or as space available for development; the unique demands of reclamation in the arid west; and the impact of new federal and state policies on resource management, given the recent trend of western states-rights militancy and population shifts to the southwest. Separate abstracts were prepared for 12 papers selected for the Energy Data Base (EDB) and Energy Abstracts for Policy Analysis (EAPA). Two papers were processed earlier.

  10. Estimate of shallow groundwater recharge in the Hadejia-Nguru Wetlands, semi-arid northeastern Nigeria

    Science.gov (United States)

    Goes, B. J. M.

    1999-06-01

    The Hadejia-Nguru Wetlands are annually inundated flood plains in semi-arid northeastern Nigeria. The area has a unique ecosystem that forms a natural barrier against the encroachment of the Sahara desert. Both the rich wetland vegetation and local farmers using shallow tube wells depend on a groundwater mound (with a water table less than 6 m below the surface) that is present in the unconfined aquifer under the flood-plain area. Using well records (1991-97) and a hydrogeologic profile based on piezometers that were monitored for two years, it is shown that recharge through the annually inundated flood plains is the source of the groundwater mound. Maintenance of the groundwater-recharge function of the flood plains depends on wet-season releases from two large upstream dams. On the basis of a water-budget method, the mean (1991-97) wet-season unconfined groundwater recharge in the flood-plain area between Hadejia and Nguru and in the immediate vicinity (1250 km2) is estimated to be 132 mm (range, 73-197 mm). Outflow from the unconfined flood-plain aquifer to the unconfined upland aquifer is approximately 10% of the wet-season flood-plain recharge. The unconfined groundwater outflow from the flood-plain area can provide a significant contribution to the present-day rural water supply in the surrounding uplands, but it does not offer much potential for additional groundwater abstraction. In addition to outflow to the upland aquifer (˜14 mm), the distribution of the annually recharged water volume of the shallow flood-plain aquifer is (1) domestic uses (3 mm), (2) small-scale irrigation (˜15 mm), and (3) evapotranspiration ( 1 100 mm). Along the hydrogeologic profile, the recharge in the upland (i.e., outflow from the unconfined flood-plain aquifer and possibly diffuse rain-fed recharge) is in balance with the water uses (i.e., domestic uses, groundwater outflow, and evapotranspiration). The absence of a seasonal water-level trend in the two piezometers in the

  11. Is There a Place for Integrated Medicine in the Western World ? Why not?

    Institute of Scientific and Technical Information of China (English)

    郭宣和

    2001-01-01

    @@The title of my paper questions whether there is room available in the western world for a combination of traditional Chinese medicine (CM) and western orthodox medicine (WM) to become an integrated whole or at least, whether the two medicines can work peacefully hand-in-hand along the clinical and scientific lines? The question is not coming out of the blue, since it does presuppose many arising problems across the road of the process making. The question also implicitly refers to another question: what is the big difference between the Chinese and the western discourses in this context?

  12. Impact of Direct Soil Moisture and Revised Soil Moisture Index Methods on Hydrologic Predictions in an Arid Climate

    Directory of Open Access Journals (Sweden)

    Milad Jajarmizadeh

    2014-01-01

    Full Text Available The soil and water assessment tool (SWAT is a physically based model that is used extensively to simulate hydrologic processes in a wide range of climates around the world. SWAT uses spatial hydrometeorological data to simulate runoff through the computation of a retention curve number. The objective of the present study was to compare the performance of two approaches used for the calculation of curve numbers in SWAT, that is, the Revised Soil Moisture Index (SMI, which is based on previous meteorological conditions, and the Soil Moisture Condition II (SMCII, which is based on soil features for the prediction of flow. The results showed that the sensitive parameters for the SMI method are land-use and land-cover features. However, for the SMCII method, the soil and the channel are the sensitive parameters. The performances of the SMI and SMCII methods were analyzed using various indices. We concluded that the fair performance of the SMI method in an arid region may be due to the inherent characteristics of the method since it relies mostly on previous meteorological conditions and does not account for the soil features of the catchment.

  13. Season mediates herbivore effects on litter and soil microbial abundance and activity in a semi-arid woodland

    Energy Technology Data Exchange (ETDEWEB)

    Classen, Aimee T [ORNL; Overby, Stephen [USFS; Hart, Stephen C [Northern Arizona University; Koch, George W [Northern Arizona University; Whitham, Thomas G [Northern Arizona University

    2007-01-01

    Herbivores can directly impact ecosystem function by altering litter quality entering an ecosystem or indirectly by affecting a shift in the microbial community that mediate nutrient processes. We examine herbivore susceptibility and resistance effects on litter microarthropod and soil microbial communities to test the general hypothesis that herbivore driven changes in litter inputs will feedback to the microbial community. Our study population consisted of individual trees that are susceptible or resistant to the stem-boring moth (Dioryctria albovittella) and trees that herbivores have been manually removed since 1982. Moth herbivory increased pi on litter nitrogen concentrations (16%) and canopy precipitation infiltration (28%), both significant factors influencing litter and soil microbial populations. Our research resulted in three major conclusions: 1) In spite of an increase in litter quality, herbivory does not change litter microarthropod abundance or species richness. 2) Herbivore susceptibility alters bulk soil microbial communities, but not soil properties. 3) Season has a strong influence on microbial communities, and their response to herbivore inputs, in this semi-arid ecosystem.

  14. Chemical composition and antibacterial activity of essential oil of Launaea lanifera Pau grown in Algerian arid steppes

    Institute of Scientific and Technical Information of China (English)

    Tarek; Benmeddour; Hocine; Laouer; Salah; Akkal; Guido; Flamini

    2015-01-01

    Objective: To evaluate the essential oil composition and the antibacterial activity of an Algerian endemic plant, Launaea lanifera Pau(L. lanifera), grown in arid steppe regions.Methods: L. lanifera essential oil was isolated from aerial parts by steam distillation and its chemical composition was evaluated by gas chromatographyflame ionization detector and gas chromatography with electron impact mass spectrometry. Furthermore, its in vitro antibacterial activity against four bacterial strains was tested following the agar disk diffusion method.Results: This species had a very low essential oil yield(0.005%). Twenty-four(92.6%)individual components were identified. The main constituents were hexahydrofarnesyl acetone(31.6%),(E)-b-ionone(8.5%),(E)-b-damascenone(7.0%), 2-methyltetradecane(3.8%), n-heptadecane(3.8%), limonene(2.8%) and b-caryophyllene(2.8%). No noteworthy antimicrobial activity was observed on the tested bacteria, neither Gram negative nor Gram positive.Conclusions: This is the first report on the volatile constituents and antibacterial activity of L. lanifera. The studied essential oil does not possess significant activity against the tested microorganisms.

  15. 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.

  16. The Western Environmental Technology Office (WETO), Butte, Montana, technology summary

    International Nuclear Information System (INIS)

    This document has been prepared by the DOE Environmental Management (EM) Office of Technology Development (OTD) to highlight its research, development, demonstration, testing, and evaluation activities funded through the Western Environmental Technology Office (WETO) in Butte, Montana. Technologies and processes described have the potential to enhance DOE's cleanup and waste management efforts, as well as improve US industry's competitiveness in global environmental markets. WETO's environmental technology research and testing activities focus on the recovery of useable resources from waste. Environmental technology development and commercialization activities will focus on mine cleanup, waste treatment, resource recovery, and water resource management. Since the site has no record of radioactive material use and no history of environmental contamination/remediation activities, DOE-EM can concentrate on performing developmental and demonstration activities without the demands of regulatory requirements and schedules. Thus, WETO will serve as a national resource for the development of new and innovative environmental technologies

  17. Climatic information of Western Sahel (1535–1793 AD in original documentary sources

    Directory of Open Access Journals (Sweden)

    V. Millán

    2014-09-01

    Full Text Available The Sahel is the semi-arid transition zone between arid Sahara and humid tropical Africa, extending approximately 10–20° N from Mauritania in the West to Sudan in the East. The African continent, one of the most vulnerable regions to climate change, is subject to frequent droughts and famine. One climate challenge research is to isolate those aspects of climate variability that are natural from those that are related to human influences. Therefore, the study of climatic conditions before mid-19th century, when anthropogenic influence was of minor importance, is very interesting. In this work the frequency of extreme events, such as droughts and floods, in Western Sahel from the 16th to 18th centuries is investigated using documentary data. Original manuscripts with historical chronicles from Walata and Nema (Mauritania, Timbuktu and Arawan (Mali, and Agadez (Niger have been analyzed. Information on droughts, intense rainfall, storms and floods, as well as socioeconomic aspects (famines, pests, scarcity, prosperity has been codified in an ordinal scale ranging from −2 (drought and famines to +2 (floods to obtain a numerical index of the annual rainfall in the region. Results show wet conditions in the 17th century, as well as dry conditions in the 18th century (interrupted by a short wet period in the 1730s decade.

  18. Wallace Stegner and the Western Environment: Hydraulics, Placelessness, and (Lack of Identity

    Directory of Open Access Journals (Sweden)

    Fredrik Chr. Brøgger

    2011-09-01

    Full Text Available This article is chiefly concerned with Wallace Stegner’s ideas of aridity as the key to the understanding of the history and culture of the American West. It first examines the arguments of some major books published in the 1980s that helped strengthen Stegner’s conviction that the West was heading towards environmental disaster due to the rapidly increasing depletion of its rivers and aquifers, a projected ecological crisis that has grown even more acute at the beginning of the 21st century. The subsequent focus of this article, however, is on Stegner’s predominant proposition that the abuse of the arid nature of the West – the rampant disregard of its environmental limitations – is a product of a mindset and a culture that he finds particularly Western. In the course of his analysis, Stegner sees the rootlessness that typified his own family history as a direct reflection of the transientness characteristic of the collective history of the American West, which served to hamper the evolution of a sense of place that in his view is the prerequisite for a genuine stewardship of the land.

  19. Environmental isotope application for determination artificial recharge efficiency, cases from arid and semi-arid areas of Jordan

    International Nuclear Information System (INIS)

    Full text: Jordan is one of the arid and semi arid regions where 90% of the country receives less than 200 mm of annual precipitation. Artificial recharge and surface water harvesting has been given an importance and priorities in the last years. Four dams have been taken under study of environmental isotope hydrology to define the efficiency of the artificial recharge to the groundwater, two dams are located in the highland areas (altitude ∼ 740m above see level) and the other two dams at the main escarpment of the Jordan Valley graben (altitude is around -150m below sea level). Monthly and several sampling campaigns from the dams and the surrounding wells of the stable isotopes oxygen-18 (18O), Deuterium (2H) and radioactive tritium (3H) including complete chemical have been sampled and analyzed within the period 1995-2001. This has existed within the framework of technical cooperation projects with the IAEA, RER/8/002 and RAW/8/007. The aquifer, which is outcropping at upper dams, is formed from chert and limestone of campanian and turonian age as Siwaqa dam and overlies by Basalt at Khlidiya dam (upland areas) where the aquifer is formed from sandstone aquifer at Kafrain and Shueib dams at the Jordan valley. The diagrams of 18O and 2H of Siwaqa and Khadiya dams and some selected surrounding wells indicates that there is significant enrichment of the stable isotopes in the groundwater wells near the dams especially at the first years of dams operation which indicates a natural recharge of the enriched water from both lakes. The significant accumulations of silts and sediments at the bottom of both dams makes clogging and reduce the recharge, unless infiltration to the groundwater could occur through dam's escarpment after flooding and water rising. The regression line of the diagram of 18O and deuterium (2H) of the four wells mentioned above including the dam water for the period 1995-2001 has high correlation coefficient, this is represented by the following

  20. The Shape of a Western

    DEFF Research Database (Denmark)

    Nielsen, Jakob Isak

    2007-01-01

    The article is written for an issue on the Western genre. By means of a comparative analysis of Winchester '73 (Anthony Mann, 1950) and The Man from Laramie (Anthony Mann, 1955) the article accounts for stylistic, narrative, generic and theoretical implications of the transition from Academy ratio...

  1. Western Transitology and Chinese Reality

    DEFF Research Database (Denmark)

    Brødsgaard, Kjeld Erik

    It is the object of considerable debate in Western scholarship whether an authoritarian political order dominated by a strong communist party can continue to exist in China given the many challenges stemming from internal reform and the impact of globalization. Will China eventually turn democratic...

  2. Marketing hotelu Best Western Kampa

    OpenAIRE

    Bubla, Ladislav

    2009-01-01

    The bachelor thesis deals with the development of tourist's accommodation in Prague with the focus on the competition of the hotel Best Western Kampa. The thesis also analyses currently used components of the marketing mix of selected hotel and proceeds its SWOT-analyse. On the basis of synthesis of ascertained information it suggests the conceivable recommendations.

  3. ALIENS IN WESTERN STREAM ECOSYSTEMS

    Science.gov (United States)

    The USEPA's Environmental Monitoring and Assessment Program conducted a five year probability sample of permanent mapped streams in 12 western US states. The study design enables us to determine the extent of selected riparian invasive plants, alien aquatic vertebrates, and some ...

  4. Gendering Citizenship in Western Europe

    DEFF Research Database (Denmark)

    Siim, Birte; Lister, Ruth; Williams, Fiona;

    The first part of the book clarifies the ways that the concept of citizenship has developed historically and is understood today in a range of Western European welfare states. It elaborates on the contempory framing of debates and struggles around citizenship. This provides a framework for thee...

  5. Global synthesis of groundwater recharge in semiarid and arid regions

    Science.gov (United States)

    Scanlon, Bridget R.; Keese, Kelley E.; Flint, Alan L.; Flint, Lorraine E.; Gaye, Cheikh B.; Edmunds, W. Michael; Simmers, Ian

    2006-10-01

    Global synthesis of the findings from 140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40-374 000 km2) range from 0.2 to 35 mm year-1, representing 0.1-5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to 720 m year-1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Niño Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Niños (1977-1998) relative to periods dominated by La Niñas (1941-1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year-1 during the Sahel drought (1970-1986) to 150 mm year-1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in the SW US. The impact of LU

  6. Ecosystem Services Evaluation and Its Spatial Characteristics in Central Asia’s Arid Regions: A Case Study in Altay Prefecture, China

    Directory of Open Access Journals (Sweden)

    Qi Fu

    2015-06-01

    Full Text Available Ecosystem services are important foundations to realize the sustainable development of economy and society. The question of how to quantitatively evaluate ecosystem services in a scientific way is a hot topic among international researchers. Studying the spatial characteristics of ecosystem services in arid regions can provide the theoretical and practical basis for coordinating a sustainable man-land relationship. Altay Prefecture of China, a typical arid region in Central Asia, was taken as the study area. It is on the Silk Road economic belt, which is a key region in the program of developing Western China. Three ecosystem services: water yield, soil conservation, and net primary productivity were quantitatively evaluated. The results show that (1 the spatial distribution pattern has a distinct characteristic of zonality; (2 mountain zone and mountain-oasis ecotone are the hotspots of ecosystem services; and (3 the correlation between water yield and net primary productivity shows a gradual increasing trend as altitude decreases. Objective analysis from the aspect of mechanism is given by discussing the causes of this particular pattern. It is found that altitude and slope have great influence on spatial distributions of ecosystem services, zones with the most amount of services are distributed in 1.5–2 km-altitude and 15–25°-slope. Different human activities in different regions and spatial distance decay of ecosystem services also contribute to the formation of spatial pattern. Thus, overgrazing, logging and mining are prohibited in mountain zones and mountain-oasis ecotones. Scholars are encouraged to focus on desert-ecosystem services in the future.

  7. Modelling forest lines and forest distribution patterns with remote sensing data in a mountainous region of semi-arid Central Asia

    Directory of Open Access Journals (Sweden)

    M. Klinge

    2014-10-01

    Full Text Available Satellite images and digital elevation models provide an excellent database to analyse forest distribution patterns and forest limits in the mountain regions of semi-arid Central Asia at the regional scale. For the investigation area in the northern Tien Shan a strong relation between forest distribution and climate conditions could be found. Additionally areas of potential human impact on forested areas are identified at lower elevations near the mountain border based on an analysis of the differences of climatic preconditions and present occurrence of forest stands. The distribution of spruce (Picea schrenkiana forests is hydrologically limited by a minimum annual precipitation of 250 mm and thermally by a minimum monthly mean temperature of 5 °C during the growing season. While the actual lower forest limit increases from 1600 m a.s.l. in the northwest to 2600 m a.s.l. in the southeast, the upper forest limit takes the same course from 1800 to 2900 m a.s.l. In accordance with the main wind directions, the steepest gradient of both forest lines and the greatest local vertical extent of the forest belt of 500 to 600 m and maximum 900 m occur at the northern and western mountain fronts. The forests in the investigation area are strongly restricted to north facing-slopes, which is a common feature in semi-arid Central Asia. Based on the presumption that variations in local climate conditions are a function of topography, the potential forest extent was analysed with regard to the parameters slope, aspect, solar radiation input and elevation. All four parameters showed a strong relationship to forest distribution, yielding a total potential forest area that is 3.5 times larger than the present forest remains of 502 km2.

  8. Modelling forest lines and forest distribution patterns with remote sensing data in a mountainous region of semi-arid Central Asia

    Science.gov (United States)

    Klinge, M.; Böhner, J.; Erasmi, S.

    2014-10-01

    Satellite images and digital elevation models provide an excellent database to analyse forest distribution patterns and forest limits in the mountain regions of semi-arid Central Asia at the regional scale. For the investigation area in the northern Tien Shan a strong relation between forest distribution and climate conditions could be found. Additionally areas of potential human impact on forested areas are identified at lower elevations near the mountain border based on an analysis of the differences of climatic preconditions and present occurrence of forest stands. The distribution of spruce (Picea schrenkiana) forests is hydrologically limited by a minimum annual precipitation of 250 mm and thermally by a minimum monthly mean temperature of 5 °C during the growing season. While the actual lower forest limit increases from 1600 m a.s.l. in the northwest to 2600 m a.s.l. in the southeast, the upper forest limit takes the same course from 1800 to 2900 m a.s.l. In accordance with the main wind directions, the steepest gradient of both forest lines and the greatest local vertical extent of the forest belt of 500 to 600 m and maximum 900 m occur at the northern and western mountain fronts. The forests in the investigation area are strongly restricted to north facing-slopes, which is a common feature in semi-arid Central Asia. Based on the presumption that variations in local climate conditions are a function of topography, the potential forest extent was analysed with regard to the parameters slope, aspect, solar radiation input and elevation. All four parameters showed a strong relationship to forest distribution, yielding a total potential forest area that is 3.5 times larger than the present forest remains of 502 km2.

  9. Long-term water balance and conceptual model of a semi-arid mountainous catchment

    Science.gov (United States)

    Long-term water balance investigations are needed to better understand hydrologic systems, especially semi-arid mountainous catchments. These systems exhibit considerable interannual variability in precipitation as well as spatial variation in snow accumulation, soils, and vegetation. This study e...

  10. Insertional Mutagenesis Identifies a STAT3/Arid1b/β-catenin Pathway Driving Neurofibroma Initiation

    Directory of Open Access Journals (Sweden)

    Jianqiang Wu

    2016-03-01

    Full Text Available To identify genes and signaling pathways that initiate Neurofibromatosis type 1 (NF1 neurofibromas, we used unbiased insertional mutagenesis screening, mouse models, and molecular analyses. We mapped an Nf1-Stat3-Arid1b/β-catenin pathway that becomes active in the context of Nf1 loss. Genetic deletion of Stat3 in Schwann cell progenitors (SCPs and Schwann cells (SCs prevents neurofibroma formation, decreasing SCP self-renewal and β-catenin activity. β-catenin expression rescues effects of Stat3 loss in SCPs. Importantly, P-STAT3 and β-catenin expression correlate in human neurofibromas. Mechanistically, P-Stat3 represses Gsk3β and the SWI/SNF gene Arid1b to increase β-catenin. Knockdown of Arid1b or Gsk3β in Stat3fl/fl;Nf1fl/fl;DhhCre SCPs rescues neurofibroma formation after in vivo transplantation. Stat3 represses Arid1b through histone modification in a Brg1-dependent manner, indicating that epigenetic modification plays a role in early tumorigenesis. Our data map a neural tumorigenesis pathway and support testing JAK/STAT and Wnt/β-catenin pathway inhibitors in neurofibroma therapeutic trials.

  11. Insertional Mutagenesis Identifies a STAT3/Arid1b/β-catenin Pathway Driving Neurofibroma Initiation.

    Science.gov (United States)

    Wu, Jianqiang; Keng, Vincent W; Patmore, Deanna M; Kendall, Jed J; Patel, Ami V; Jousma, Edwin; Jessen, Walter J; Choi, Kwangmin; Tschida, Barbara R; Silverstein, Kevin A T; Fan, Danhua; Schwartz, Eric B; Fuchs, James R; Zou, Yuanshu; Kim, Mi-Ok; Dombi, Eva; Levy, David E; Huang, Gang; Cancelas, Jose A; Stemmer-Rachamimov, Anat O; Spinner, Robert J; Largaespada, David A; Ratner, Nancy

    2016-03-01

    To identify genes and signaling pathways that initiate Neurofibromatosis type 1 (NF1) neurofibromas, we used unbiased insertional mutagenesis screening, mouse models, and molecular analyses. We mapped an Nf1-Stat3-Arid1b/β-catenin pathway that becomes active in the context of Nf1 loss. Genetic deletion of Stat3 in Schwann cell progenitors (SCPs) and Schwann cells (SCs) prevents neurofibroma formation, decreasing SCP self-renewal and β-catenin activity. β-catenin expression rescues effects of Stat3 loss in SCPs. Importantly, P-STAT3 and β-catenin expression correlate in human neurofibromas. Mechanistically, P-Stat3 represses Gsk3β and the SWI/SNF gene Arid1b to increase β-catenin. Knockdown of Arid1b or Gsk3β in Stat3(fl/fl);Nf1(fl/fl);DhhCre SCPs rescues neurofibroma formation after in vivo transplantation. Stat3 represses Arid1b through histone modification in a Brg1-dependent manner, indicating that epigenetic modification plays a role in early tumorigenesis. Our data map a neural tumorigenesis pathway and support testing JAK/STAT and Wnt/β-catenin pathway inhibitors in neurofibroma therapeutic trials. PMID:26904939

  12. Polyacrylamide Molecular Weight and Phosphogypsum Effects on Infiltration and Erosion in Semi-Arid Soils

    Science.gov (United States)

    Seal formation at the surface of semi-arid soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  13. On water repellency, humidity, fire, and wind erosion in arid landscapes

    Science.gov (United States)

    Studies of water repellent soils have usually focused on their effect on infiltration and runoff. In arid regions, however, the landscape is often shaped more by wind than by water, with important implications for ecology and land management. In a series of field, laboratory, and theoretical experim...

  14. TIME SERIES MODELING OF MONTHLY RAINFALL IN ARID AREAS: CASE STUDY FOR SAUDI ARABIA

    Directory of Open Access Journals (Sweden)

    Nidhal Saada

    2014-01-01

    Full Text Available Stochastic techniques are essential in planning and management of water resources systems especially in arid and semi-arid areas where water is scarce. The forecasting of future events requires identifying proper stochastic models to be used in this process. For this purpose, a Periodic ARMA (PARMA model and a temporal disaggregation models were used in this study to investigate weather they are appropriate for modeling the monthly rainfall data in Saudi Arabia. Results showed PARMA and temporal disaggregation models performed well in modeling the monthly rainfalls in Saudi Arabia. These models were able to preserve the basic seasonal statistics of the observed data well as preserving the seasonal correlation structure observed in the historical data. However, the PARMA model did not perform well at the annual level. In contrast, the disaggregation model performed well in preserving the correlation structure of the historical data at the annual level. Thus, these models can be used in modeling and forecasting of monthly rainfall in Arid and semi-arid areas.

  15. Water sources accessed by arid zone riparian trees in highly saline environments, Australia.

    Science.gov (United States)

    Costelloe, Justin F; Payne, Emily; Woodrow, Ian E; Irvine, Elizabeth C; Western, Andrew W; Leaney, Fred W

    2008-05-01

    The flow regimes of arid zone rivers are often highly variable, and shallow groundwater in the alluvial aquifers can be very saline, thus constraining the availability and quality of the major water sources available to riparian trees-soil water, shallow groundwater and stream water. We have identified water sources and strategies used by riparian trees in more highly saline and arid conditions than previously studied for riparian trees of arid zone rivers. Our research focused on the riparian species Eucalyptus coolabah, one of the major riparian trees of ephemeral arid zone rivers in Australia. The water sources available to this riparian tree were examined using delta(18)O isotope data from xylem, soil water, groundwater and surface water. Additionally, soil chloride and matric potential data were used to infer zones of water availability for root uptake. Despite the saline conditions, the trees used a mixture of soil water and groundwater sources, but they did not use surface water directly. The study identified three strategies used to cope with typically high groundwater and soil water salinities. Firstly, the trees preferentially grow in zones of most frequent flushing by infiltrating streamflow, such as the bank-tops of channels. Secondly, the trees limit water use by having low transpiration rates. Thirdly, the trees are able to extract water at very low osmotic potentials, with water uptake continuing at chloride concentrations of at least 20,000-30,000 mg L(-1). PMID:18270743

  16. Effects of climate on the productivity of desert truffles beneath hyper-arid conditions.

    Science.gov (United States)

    Bradai, Lyès; Bissati, Samia; Chenchouni, Haroun; Amrani, Khaled

    2015-07-01

    Desert truffles are edible hypogenous fungi that are very well adapted to conditions of aridity in arid and semi-arid regions. This study aims to highlight the influence of climatic factors on the productivity of desert truffles under hyper-arid climatic conditions of the Sahara Desert in Algeria, with assumptions that the more varying climatic factors, mainly rainfall, are more crucial for the development and production of desert truffles. At seven separate sites, desert truffles were collected by systematic sampling between 2006 and 2012. The effects of climate parameters of each site on the productivities (g/ha/year) of desert truffle species were tested using generalized linear models (GLMs). The annual mean of the total production recorded for all three harvested species (Terfezia arenaria, Terfezia claveryi, and Tirmania nivea) was 785.43 ± 743.39 g/ha. Tirmania nivea was commonly present over the sampled sites with an occurrence of 70 ± 10.1%. GLMs revealed that total and specific productivities were closely positively related to autumnal precipitations occurring during October-December, which is the critical pre-breeding period for both desert truffles and host plant species. The other climatic parameters have statistically no effect on the annual variation of desert truffle productivity. PMID:25164975

  17. Plant-associated microbiomes in arid lands: diversity, ecology and biotechnological potential

    KAUST Repository

    Soussi, Asma

    2015-08-28

    Background: Aridification is a worldwide serious threat directly affecting agriculture and crop production. In arid and desert areas, it has been found that microbial diversity is huge, built of microorganisms able to cope with the environmental harsh conditions by developing adaptation strategies. Plants growing in arid lands or regions facing prolonged abiotic stresses such as water limitation and salt accumulation have also developed specific physiological and molecular stress responses allowing them to thrive under normally unfavorable conditions. Scope: Under such extreme selection pressures, special root-associated bacterial assemblages, endowed with capabilities of plant growth promotion (PGP) and extremophile traits, are selected by the plants. In this review, we provide a general overview on the microbial diversity in arid lands and deserts versus specific microbial assemblages associated with plants. The ecological drivers that shape this diversity, how plant-associated microbiomes are selected, and their biotechnological potential are discussed. Conclusions: Selection and recruitment of the plant associated bacterial assemblages is mediated by the combination of the bio-pedo-agroclimatic conditions and the plant species or varieties. Diversity and functional redundancy of these associated PGPR makes them very active in supporting plant improvement, health and resistance to drought, salt and related stresses. Implementing proper biotechnological applications of the arid and desert-adapted PGPR constitute the challenge to be raised.

  18. Canola integration into semi-arid wheat cropping systems of the inland Pacific Northwestern USA

    Science.gov (United States)

    The inland Pacific Northwestern USA (iPNW) wheat-producing region has a diversity of environments and soils, yet it lacks crop diversity and is one of the few semi-arid wheat-growing regions without significant integration of oilseeds. Four major agroecological zones, primarily characterised by wate...

  19. Isotopic composition of rainfall and runoff in a small arid basin with implications for deep percolation

    International Nuclear Information System (INIS)

    The aim of this work was to characterize the isotopic composition of potential recharge in an arid rocky watershed. Unique field observations were obtained from an arid watershed in the Negev Highlands, Israel, through utilization of the dynamic variations in the isotopic composition of rainfall and runoff. The hydrological system's inputs are rainfall and its isotopic composition. Rainfall and runoff were sampled in eight storms. High variability in the isotopic composition of rainfall was observed during any single rainstorm. The isotopic distribution in the runoff at the outlet of the basin appeared often not to be correlated to the isotopic patterns of the associated rain storm. A new mathematical model was developed to describe these physical processes. The model called A Double-Component Kinematic Wave Flow and Transport Approach, was designated to assess the dynamic isotopic distribution in arid rain storms and runoff. This model simulates the transport of rainfall into overland flow and runoff in an arid rocky watershed with uniformly distributed shallow depression storage. A numerical solution for the problem was developed, to estimate the depression storage parameters. The model also reflects the isotopic memory effect due to the depression storage between sequential rain showers. A good agreement between the observed and computed hydrograph and the change of the δ18O values in runoff in time confirms the validity of the model. (author) 138 figs., 125 refs

  20. Life at the hyperarid margin: novel bacterial diversity in arid soils of the Atacama Desert, Chile

    Science.gov (United States)

    Neilson, Julia W.; Quade, Jay; Ortiz, Marianyoly; Nelson, William M.; Legatzki, Antje; Tian, Fei; LaComb, Michelle; Betancourt, Julio L.; Wing, Rod A.; Soderlund, Carol A.; Maier, Raina M.

    2012-01-01

    Nearly half the earth's surface is occupied by dryland ecosystems, regions susceptible to reduced states of biological productivity caused by climate fluctuations. Of these regions, arid zones located at the interface between vegetated semiarid regions and biologically unproductive hyperarid zones are considered most vulnerable. The objective of this study was to conduct a deep diversity analysis of bacterial communities in unvegetated arid soils of the Atacama Desert, to characterize community structure and infer the functional potential of these communities based on observed phylogenetic associations. A 454-pyrotag analysis was conducted of three unvegetated arid sites located at the hyperarid-arid margin. The analysis revealed communities with unique bacterial diversity marked by high abundances of novel Actinobacteria and Chloroflexi and low levels of Acidobacteria and Proteobacteria, phyla that are dominant in many biomes. A 16S rRNA gene library of one site revealed the presence of clones with phylogenetic associations to chemoautotrophic taxa able to obtain energy through oxidation of nitrite, carbon monoxide, iron, or sulfur. Thus, soils at the hyperarid margin were found to harbor a wealth of novel bacteria and to support potentially viable communities with phylogenetic associations to non-phototrophic primary producers and bacteria capable of biogeochemical cycling.

  1. Carbon accumulation in arid croplands of northwest China: pedogenic carbonate exceeding organic carbon

    Science.gov (United States)

    Wang, Xiujun; Wang, Jiaping; Xu, Minggang; Zhang, Wenju; Fan, Tinglu; Zhang, Juan

    2015-06-01

    Soil carbonate (SIC) exceeds organic carbon (SOC) greatly in arid lands, thus may be important for carbon sequestration. However, field data for quantifying carbonate accumulation have been lacking. This study aims to improve our understanding of SIC dynamics and its role in carbon sequestration. We analyzed two datasets of SOC and SIC and their 13C compositions , one with over 100 soil samples collected recently from various land uses in the Yanqi Basin, Xinjiang, and the other with 18 archived soil samples from a long-term experiment (LTE) in Pingliang, Gansu. The data from the Yanqi Basin showed that SOC had a significant relationship with SIC and pedogenic carbonate (PIC); converting shrub land to cropland increased PIC stock by 5.2 kg C m-2, which was 3.6 times of that in SOC stock. The data from the LTE showed greater accumulation of PIC (21-49 g C m-2 year-1) than SOC (10-39 g C m-2 year-1) over 0-20 cm. Our study points out that intensive cropping in the arid and semi-arid regions leads to an increase in both SOC and PIC. Increasing SOC through straw organic amendments enhances PIC accumulation in the arid cropland of northwestern China.

  2. Spatio-Temporal Analysis of Droughts in Semi-Arid Regions by Using Meteorological Drought Indices

    Czech Academy of Sciences Publication Activity Database

    Shahabfar, A.; Eitzinger, Josef

    2013-01-01

    Roč. 4, č. 2 (2013), s. 94-112. ISSN 2073-4433 Institutional support: RVO:67179843 Keywords : drought monitoring * drought index * standardized precipitation index * semi-arid region * Iran Subject RIV: EH - Ecology, Behaviour Impact factor: 1.048, year: 2013

  3. Energetics of the green iguana (Iguana iguana) in a semi-arid environment

    OpenAIRE

    van Marken Lichtenbelt, Wouter David

    1991-01-01

    Energy budgets in the herbivorous green iguana (Iguana Iguana) were studied from April 1985-October 1988 in a strongly seasonal environment on the semi-arid island Curacao (Netherlands Antilles) under the auspices of the CARMABI Foundation in cooperation with the State University of Groningen (The Netherlands). ... Zie: Summary

  4. Extensive Green Roof Species and Soilless Media Evaluations in Semi-arid Colorado

    Science.gov (United States)

    In the high elevation, semi-arid climate of Colorado, green roofs have not been scientifically tested. This research examined alternative plant species, soilless media blends and plant interactions on an existing, modular-extensive (shallow, 10 cm deep) green roof in Denver, Colo...

  5. The first Editorial Board meeting of Journal of Arid Land in 2010 was held in Urumqi

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On Sep. 5, 2010, the first Editorial Board meeting of Journal of Arid Land (JAL) was held in Urumqi. The director of Xinjiang Institute of Ecology and Geography (XIEG), Chinese Academy of Sciences (CAS) and the editor-in-chief of JAL, Professor Chen Xi, another editor-in-chief, Professor Li Bailian, University of California,

  6. Potential methanotrophic and methanogenic activity of soil crusts in semi-arid Tabernas region

    Czech Academy of Sciences Publication Activity Database

    Macková, Jana; Macek, P.; Pugnaire, F.I.; Šimek, Miloslav

    Dijon : INRA, 2014. s. 484. [Global Soil Biodiversity Conference. Assessing soil biodiversity and its role for ecosystem services /1./. 02.12.2014-05.12.2014, Dijon] Institutional support: RVO:60077344 Keywords : methane oxidation and production * soil crusts * semi-arid zone * nutrient content Subject RIV: EH - Ecology, Behaviour

  7. Infiltration and planting pits for improved water management and maize yield in semi-arid Zimbabwe

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.; Nyagumbo, I.

    2014-01-01

    Realising that rainwater harvesting (RWH) improves crop productivity, smallholder farmers in semi-arid Zimbabwe modified contour ridges traditionally used for rainwater management by digging infiltration pits inside contour ridge channels in order to retain more water in crop fields. However, scient

  8. The ecohydrology of the soil-vegetation system restoration in arid zones: a review

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Arid zones, which cover approximately 40 percent of the earth’s land surface, support complicated and widely varied ecological systems. As such, arid zones are an important composition of the global terrestrial ecosystem, and water is the key and abiotic lim-ited factor in ecosystem-driven processes in these areas. Ecohydrology is a new cross discipline that provides, in an objective and comprehensive manner, novel ideas and approaches to the evaluation of the interaction and feedback mechanisms involved in the soil-vegetation systems in arid zones. In addition, ecohydrology provides a theoretical basis of ecological restoration that is cen-tered on vegetation construction. In this paper, long-term monitoring and local observations in the transitional belt between a de-sertified steppe and a steppified desert at the Shapotou Desert Research and Experiment Station, Tengger Desert, in northern China, were evaluated. The primary achievements and related research progress regarding ecohydrology in arid zones were analyzed and summarized, as a keystone, and the response of soil ecohydrological processes to the changes in the species composition, structure, and function of sandland vegetation was discussed. Meanwhile, the long-term ecological effects and mechanism of regulation of vegetation on soil habitat and on water-cycling were considered. As a vital participant in the ecohydrological processes of soil-vegetation systems, the studies on biological soil crusts was also summarized, and related theoretical models of restoration based on the water balance was reviewed.

  9. Functional group and species responses to spring precipitation in three semi-arid rangeland ecosystems

    Science.gov (United States)

    Determining if precipitation-induced changes to forage production and basal and foliar cover in semi-arid rangelands are species-specific, functional group-specific or ubiquitous across species and functional groups will enhance decision making among producers and increase precision of forage produc...

  10. Long-term runoff and sediment yields from small semi-arid watersheds in southern Arizona

    Science.gov (United States)

    This study presents analysis of 34 years of precipitation, runoff and sediment data collected from 8 small (1.1 to 4.0 ha) semi-arid rangeland watersheds in southern Arizona, USA. Average annual precipitation ranged between 354 mm and 458 mm with 53% of the total rainfall occurring from July throug...

  11. Organic matter and water addition enhance soil respiration in an arid region.

    Directory of Open Access Journals (Sweden)

    Liming Lai

    Full Text Available 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 parameters. It was found that both fresh organic matter and water enhanced soil respiration, and there was a synergistic effect of these two treatments on soil respiration increase. Water addition not only enhanced soil C emission, but also regulated soil C sequestration by fresh organic matter addition. The results indicated that the soil CO2 flux of the shrubland is likely to increase with climate change, and precipitation played a dominant role in regulating soil C balance in the shrubland of an arid region.

  12. Analysis of the temporal variation of radiation balance components in arid rice (Oryza sativa L.) culture

    International Nuclear Information System (INIS)

    The time variation of measured radiation balance components in a cultived rice area (Oryza sativa L.) under arid conditions in the Brazil central-west region was analysed. The relation between global solar radiation, radiation balance, reflected radiation and terrestrial effective radiation in three different stages of the culture development: vegetative stage; blooming and maturation, was determined. (M.C.K.)

  13. Study on the glacier variation and its runoff responses in the arid region of Northwest China

    Institute of Scientific and Technical Information of China (English)

    刘潮海; 康尔泗; 刘时银; 陈建明; 刘宗香

    1999-01-01

    The glaciers in the arid region of Northwest China are viewed as an independent system, and glacier variation and mass balance fluctuation since the Little Ice Age and in the recent decades are estimated. Based on the estimation, the threshold time of glacier runoff against the backgrounds of the current and future varying climate conditions is simulated.

  14. Land Use and Environmental Variability Impacts on the Phenology of Arid Agro-Ecosystems

    Science.gov (United States)

    Romo-Leon, Jose Raul; van Leeuwen, Willem J. D.; Castellanos-Villegas, Alejandro

    2016-02-01

    The overexploitation of water resources in arid environments often results in abandonment of large extensions of agricultural lands, which may (1) modify phenological trends, and (2) alter the sensitivity of specific phenophases to environmental triggers. In Mexico, current governmental policies subsidize restoration efforts, to address ecological degradation caused by abandonments; however, there is a need for new approaches to assess their effectiveness. Addressing this, we explore a method to monitor and assess (1) land surface phenology trends in arid agro-ecosystems, and (2) the effect of climatic factors and restoration treatments on the phenology of abandoned agricultural fields. We used 16-day normalized difference vegetation index composites from the moderate resolution imaging spectroradiometer from 2000 to 2009 to derive seasonal phenometrics. We then derived phenoclimatic variables and land cover thematic maps, to serve as a set of independent factors that influence vegetation phenology. We conducted a multivariate analysis of variance to analyze phenological trends among land cover types, and developed multiple linear regression models to assess influential climatic factors driving phenology per land cover analyzed. Our results suggest that the start and length of the growing season had different responses to environmental factors depending on land cover type. Our analysis also suggests possible establishment of arid adapted species (from surrounding ecosystems) in abandoned fields with longer times since abandonment. Using this approach, we were able increase our understanding on how climatic factors influence phenology on degraded arid agro-ecosystems, and how this systems evolve after disturbance.

  15. Camelina water use and seed yield response to irrigation scheduling in an arid environment

    Science.gov (United States)

    Camelina sativa (L.) Crantz is a promising, biodiesel-producing oilseed that could potentially be implemented as a low-input alternative crop for production in the arid southwestern USA. However, little is known about camelina’s water use, irrigation management, and agronomic characteristics in this...

  16. Contour hedgerows and grass strips in erosion and runoff control in semi-arid Kenya

    NARCIS (Netherlands)

    Kinama, J.M.; Stigter, C.J.; Ong, C.K.; Ng'ang'a, J.K.; Gichuki, F.N.

    2007-01-01

    Most early alley cropping studies in semi-arid Kenya were on fairly flat land while there is an increase in cultivated sloping land. The effectiveness of aging contour hedgerows and grass strips for erosion control on an about 15% slope of an Alfisol was compared. The five treatments were Senna siam

  17. Monitoring species richness and abundance of shorebirds in the western Great Basin

    Science.gov (United States)

    Warnock, N.; Haig, Susan M.; Oring, L.W.

    1998-01-01

    Broad-scale avian surveys have been attempted within North America with mixed results. Arid regions, such as the Great Basin, are often poorly sampled because of the vastness of the region, inaccessibility of sites, and few ornithologists. In addition, extreme variability in wetland habitat conditions present special problems for conducting censuses of species inhabiting these areas. We examined these issues in assessing multi-scale shorebird (order: Charadriiformes) censuses conducted in the western Great Basin from 1992-1997. On ground surveys, we recorded 31 species of shorebirds, but were unable to accurately estimate population size. Conversely, on aerial surveys we were able to estimate regional abundance of some shorebirds, but were unable to determine species diversity. Aerial surveys of three large alkali lakes in Oregon (Goose, Summer, and Abert Lakes) revealed > 300,000 shorebirds in one year of this study, of which 67% were American Avocets (Recurvirostra americana) and 30% phalaropes (Phalaropus spp.). These lakes clearly meet Western Hemisphere Shorebird Reserve Network guidelines for designation as important shorebird sites. Based upon simulations of our monitoring effort and the magnitude and variation of numbers of American Avocets, detection of S-10% negative declines in populations of these birds would take a minimum of 7-23 years of comparable effort. We conclude that a combination of ground and aerial surveys must be conducted at multiple sites and years and over a large region to obtain an accurate picture of the diversity, abundance, and trends of shorebirds in the western Great Basin.

  18. Joint meteorological and hydrological drought model: a management tool for proactive water resources planning of semi-arid regions

    Science.gov (United States)

    Modaresi Rad, Arash; Ahmadi Ardakani, Samira; Ghahremani, Zahra; Ghahreman, Bijan; Khalili, Davar

    2016-04-01

    Conventionally drought analysis has been limited to single drought category. Utilization of models incorporating multiple drought categories, can relax this limitation. A copula-based model is proposed, which uses meteorological and hydrological drought indices to assess drought events for ultimate management of water resources, at small scales, i.e., sub-watersheds. The study area is a sub basin located at Karkheh watershed (western Iran), utilizing 41-year data of 4 raingauge stations and one hydrometric station located upstream and at the outlet respectively. Prior to drought analysis, time series of precipitation and streamflow records are investigated for possible dependency/significant trend. Considering the semi-arid nature of the study area, boxplots are utilized to graphically capture the rainy months, which used to evaluate the degree of correlation between streamflow and precipitation records via nonparametric correlations and bivariate tail dependence. Time scales of 3- and 12-month are considered, which are used to study vulnerability of early vegetation establishment and long-term ecosystem resilience, respectively. Among four common goodness of fit tests, the Cramér-von-Mises is found preferable for defining copula distribution functions through Akaike & Bayesian information criteria and coefficient of determination. Furthermore the uncertainty associated with different copula models is measured using the concept of entropy. A new bivariate drought modeling approach is proposed through copulas. The proposed index, named standardized precipitation-streamflow index (SPSI) is compared with two separate indices of streamflow drought index (SDI) and standardized precipitation index (SPI). According to results, the SPSI could detect onset of droughts dominated by precipitation as is similarly indicated by SPI index. It also captures discordant case of normal period precipitation with dry period streamflow and vice versa. Finally, combination of severity

  19. Changes in terrestrial aridity for the period 850-2080 from the Community Earth System Model

    Science.gov (United States)

    Fu, Qiang; Lin, Lei; Huang, Jianping; Feng, Song; Gettelman, Andrew

    2016-03-01

    This study examines changes in terrestrial aridity due to both natural and anthropogenic forcing for the period 850-2080 by analyzing the Community Earth System Model (CESM) Last Millennium Ensemble simulations for 850-2005 and the CESM Large Ensemble simulations for 1920-2080. We compare terrestrial aridity in the Medieval Warm Period (MWP) (950-1250) with that in the Little Ice Age (LIA) (1550-1850), present day (PD) (1950-2005) with the last millennium (LM) (850-1850), and the future (F8.5) (2050-2080) with the LM, to place anthropogenic changes in the context of changes due to natural forcings. The aridity index defined as the ratio of annual precipitation to potential evapotranspiration, averaged over land, becomes smaller (i.e., a drier terrestrial climate) by 0.34% for MWP versus LIA (MWP-LIA), 1.4% for PD versus LM (PD-LM), and 7.8% for F8.5 versus LM (F8.5-LM). The change of terrestrial-mean aridity in PD-LM and F8.5-LM due to anthropogenic forcing is thus 4 and 20 times of that from MWP-LIA due to natural forcing, respectively. It is shown that a drier climate in PD than LM is largely due to a decrease of precipitation while a drier climate in F8.5 than LM, and MWP than LIA, is mainly caused by an increase of temperature. The terrestrial-mean aridity change in PD-LM is, however, largely driven by greenhouse gas increases as in F8.5-LM. This is because anthropogenic aerosols have a small effect on terrestrial-mean aridity but at the same time they totally alter the attributions of aridity changes to meteorological variables by causing large negative anomalies in surface air temperature, available energy, and precipitation. Different from MWP-LIA and F8.5-LM, there are large spatial inhomogeneities in P/PET changes for PD-LM in both magnitudes and signs, caused by anthropogenic aerosols, greenhouse gases, and land surface changes. The changes of terrestrial-mean P and P - E (precipitation minus evaporation) for 850-2080 are also examined. The relative

  20. Microsite Differentiation Drives the Abundance of Soil Ammonia Oxidizing Bacteria along Aridity Gradients.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T; Eldridge, David J; Singh, Brajesh K

    2016-01-01

    Soil ammonia oxidizing bacteria (AOB) and archaea (AOA) are responsible for nitrification in terrestrial ecosystems, and play important roles in ecosystem functioning by modulating the rates of N losses to ground water and the atmosphere. Vascular plants have been shown to modulate the abundance of AOA and AOB in drylands, the largest biome on Earth. Like plants, biotic and abiotic features such as insect nests and biological soil crusts (biocrusts) have unique biogeochemical attributes (e.g., nutrient availability) that may modify the local abundance of AOA and AOB. However, little is known about how these biotic and abiotic features and their interactions modulate the abundance of AOA and AOB in drylands. Here, we evaluate the abundance of amoA genes from AOB and AOA within six microsites commonly found in drylands (open areas, biocrusts, ant nests, grasses, nitrogen-fixing shrubs, and trees) at 21 sites from eastern Australia, including arid and mesic ecosystems that are threatened by predicted increases in aridity. Our results from structural equation modeling suggest that soil microsite differentiation alters the abundance of AOB (but not AOA) in both arid and mesic ecosystems. While the abundance of AOA sharply increased with increasing aridity in all microsites, the response of AOB abundance was microsite-dependent, with increases (nitrogen-fixing shrubs, ant nests), decreases (open areas) or no changes (grasses, biocrusts, trees) in abundance with increasing aridity. Microsites supporting the highest abundance of AOB were trees, nitrogen-fixing shrubs, and ant nests. These results are linked to particular soil characteristics (e.g., total carbon and ammonium) under these microsites. Our findings advance our understanding of key drivers of functionally important microbial communities and N availability in highly heterogeneous ecosystems such as drylands, which may be obscured when different soil microsites are not explicitly considered. PMID:27148194

  1. Microsite Differentiation Drives the Abundance of Soil Ammonia Oxidizing Bacteria along Aridity Gradients

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T.; Eldridge, David J.; Singh, Brajesh K.

    2016-01-01

    Soil ammonia oxidizing bacteria (AOB) and archaea (AOA) are responsible for nitrification in terrestrial ecosystems, and play important roles in ecosystem functioning by modulating the rates of N losses to ground water and the atmosphere. Vascular plants have been shown to modulate the abundance of AOA and AOB in drylands, the largest biome on Earth. Like plants, biotic and abiotic features such as insect nests and biological soil crusts (biocrusts) have unique biogeochemical attributes (e.g., nutrient availability) that may modify the local abundance of AOA and AOB. However, little is known about how these biotic and abiotic features and their interactions modulate the abundance of AOA and AOB in drylands. Here, we evaluate the abundance of amoA genes from AOB and AOA within six microsites commonly found in drylands (open areas, biocrusts, ant nests, grasses, nitrogen-fixing shrubs, and trees) at 21 sites from eastern Australia, including arid and mesic ecosystems that are threatened by predicted increases in aridity. Our results from structural equation modeling suggest that soil microsite differentiation alters the abundance of AOB (but not AOA) in both arid and mesic ecosystems. While the abundance of AOA sharply increased with increasing aridity in all microsites, the response of AOB abundance was microsite-dependent, with increases (nitrogen-fixing shrubs, ant nests), decreases (open areas) or no changes (grasses, biocrusts, trees) in abundance with increasing aridity. Microsites supporting the highest abundance of AOB were trees, nitrogen-fixing shrubs, and ant nests. These results are linked to particular soil characteristics (e.g., total carbon and ammonium) under these microsites. Our findings advance our understanding of key drivers of functionally important microbial communities and N availability in highly heterogeneous ecosystems such as drylands, which may be obscured when different soil microsites are not explicitly considered. PMID:27148194

  2. Applying soil science for restoration of post mining degraded landscapes in semi-arid Australia: challenges and opportunities

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Martini, Dylan; Erickson, Todd; Merritt, David; Dixon, Kingsley

    2015-04-01

    Introduction Current challenges in ecological restoration of post mining environments include the deficit of original topsoil which is frequently lost or damaged, and the lack of soil forming materials. A comprehensive knowledge of soil properties and processes and an adequate management of soil resources are critical to improve the restoration success of these degraded areas. In particular, understanding soil physical, chemical and biological parameters is decisive in environments where water is a limiting factor for seedling establishment and plant survival. To improve the restoration success of biodiverse semi-arid areas disturbed by mining activities (Pilbara region, Western Australia), we conducted experiments to (i) analyse changes in soil physico-chemical properties and soil microbial activity of topsoil stockpiles to optimise its handling and minimise deterioration of nutrients and soil biota, (ii) test climate effects on seedling emergence of native plant species and (iii) assess the potential of mine waste materials as a suitable growth medium for seedling emergence of native plant species under various water regimes. Methods The experimental studies were conducted in controlled environment facilities where air temperature, relative humidity and soil moisture were monitored routinely. Watering regimes were selected to represent rainfall patterns of the area. As a growth media we used material obtained from topsoil stockpiles and waste materials from an active mine site, which were mixed at different ratios. Samples were collected from different parts of the topsoil stockpiles and analysed to determine physical, chemical and biological properties. Results No large discrepancies in physical and chemical values were detected at different positions of the stockpiles. However, microbial activity was highly variable, particularly inside the stockpiles. Seedling emergence on topsoil growth media was highly dependent on climate factors with emergence rates

  3. miR-208-3p promotes hepatocellular carcinoma cell proliferation and invasion through regulating ARID2 expression

    International Nuclear Information System (INIS)

    MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at post-transcriptional level. miRNA dysregulation plays a causal role in cancer progression. In this study, miR-208-3p was highly expressed and directly repressed ARID2 expression. As a result, ARID2 expression in hepatocellular carcinoma (HCC) was decreased. In vitro, miR-208-3p down-regulation and ARID2 over-expression elicited similar inhibitory effects on HCC cell proliferation and invasion. In vivo test results revealed that miR-208-3p down-regulation inhibited HCC tumorigenesis in Hep3B cells. Moreover, ARID2 was possibly a downstream element of transforming growth factor beta1 (TGFβ1)/miR-208-3p/ARID2 regulatory pathway. These findings suggested that miR-208-3p up-regulation is associated with HCC cell progression and may provide a new target for liver cancer treatment. - Highlights: • miR-208-3p was highly expressed and directly repressed the expression of ARID2 in HCC. • miR-208-3p contributed to HCC cell progression both in vitro and in vivo. • Over-expression of ARID2 inhibited the HCC cell proliferation and invasion. • Restoration of ARID2 partly reversed the the effect of miR-208-3p down-regulation on HCC cells. • Newly regulatory pathway: miR-208-3p mediated the repression of ARID2 by TGFβ1 in HCC cells

  4. miR-208-3p promotes hepatocellular carcinoma cell proliferation and invasion through regulating ARID2 expression

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Peng; Wu, Dingguo; You, Yu; Sun, Jing; Lu, Lele; Tan, Jiaxing; Bie, Ping, E-mail: bieping2010@163.com

    2015-08-15

    MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at post-transcriptional level. miRNA dysregulation plays a causal role in cancer progression. In this study, miR-208-3p was highly expressed and directly repressed ARID2 expression. As a result, ARID2 expression in hepatocellular carcinoma (HCC) was decreased. In vitro, miR-208-3p down-regulation and ARID2 over-expression elicited similar inhibitory effects on HCC cell proliferation and invasion. In vivo test results revealed that miR-208-3p down-regulation inhibited HCC tumorigenesis in Hep3B cells. Moreover, ARID2 was possibly a downstream element of transforming growth factor beta1 (TGFβ1)/miR-208-3p/ARID2 regulatory pathway. These findings suggested that miR-208-3p up-regulation is associated with HCC cell progression and may provide a new target for liver cancer treatment. - Highlights: • miR-208-3p was highly expressed and directly repressed the expression of ARID2 in HCC. • miR-208-3p contributed to HCC cell progression both in vitro and in vivo. • Over-expression of ARID2 inhibited the HCC cell proliferation and invasion. • Restoration of ARID2 partly reversed the the effect of miR-208-3p down-regulation on HCC cells. • Newly regulatory pathway: miR-208-3p mediated the repression of ARID2 by TGFβ1 in HCC cells.

  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., Jr.

    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. Energy use pattern in production agriculture of a typical village in arid zone - Part III

    Energy Technology Data Exchange (ETDEWEB)

    Singh, H. E-mail: hsingh11@rediffmail.com; Mishra, D.; Nahar, N.M

    2004-09-01

    India has 31.71 Mha of hot arid areas, of which 61.8% is in Western Rajasthan, commonly known as the 'Thar Desert'. A detailed study of the energy use pattern in production agriculture for a representative village, Pemasar, district Bikaner of zone II (200 mm/yr {<=} annual rainfall < 300 mm/yr) has been conducted. Out of the total geographical area (945.7 ha) of the village, 693.6 ha is cultivable land. The main crops grown in the village are cluster bean, moth bean, groundnut, green gram (Kharif), wheat, mustard, gram, barley and rocket salad (Rabi). In general, Kharif crops are grown as rain fed crops, but due to low rainfall in the zone and the presence of the Indira Gandhi Canal, even Kharif crops are raised under irrigated conditions. However, the area covered under irrigation is meagre as the availability of canal water is very much limited and uncertain. Operation wise, the total energy consumed for rain fed Kharif crops is minimum (1187.6 MJ/ha) for moth bean and maximum (1261.9 MJ/ha) for cluster bean, while for irrigated crops, it is minimum (2847.3 MJ/ha) for moth bean, and maximum (12,809.6 MJ/ha) for groundnut. The average specific energy for cultivation of cluster bean (rain fed), cluster bean (irrigated), moth bean (rain fed), moth bean (irrigated) and groundnut were 11.7, 7.5, 7.7, 7.4 and 11.2 MJ/ha, respectively. Operation wise, the energy consumed for Rabi crops is minimum (3855.6 MJ/ha) for rocket salad followed by 4779.4 MJ/ha for mustard, 4845.2 MJ/ha for gram and maximum (7953.2 MJ/ha) for wheat. The average specific energy for cultivation of wheat, gram, mustard and rocket salad were 11.4, 16.5, 13.2 and 13.7 MJ/ha, respectively. The average values of estimated energy ratio for cluster bean (rain fed), cluster bean (irrigated), moth bean (rain fed), moth bean (irrigated) and groundnut were 2.1, 0.5, 3.4, 3.5 and 3.0, respectively. This suggests that the moth bean crop is more remunerating to the farmers in Kharif as compared to

  7. Energy use pattern in production agriculture of a typical village in arid zone - Part III

    International Nuclear Information System (INIS)

    India has 31.71 Mha of hot arid areas, of which 61.8% is in Western Rajasthan, commonly known as the 'Thar Desert'. A detailed study of the energy use pattern in production agriculture for a representative village, Pemasar, district Bikaner of zone II (200 mm/yr ≤ annual rainfall < 300 mm/yr) has been conducted. Out of the total geographical area (945.7 ha) of the village, 693.6 ha is cultivable land. The main crops grown in the village are cluster bean, moth bean, groundnut, green gram (Kharif), wheat, mustard, gram, barley and rocket salad (Rabi). In general, Kharif crops are grown as rain fed crops, but due to low rainfall in the zone and the presence of the Indira Gandhi Canal, even Kharif crops are raised under irrigated conditions. However, the area covered under irrigation is meagre as the availability of canal water is very much limited and uncertain. Operation wise, the total energy consumed for rain fed Kharif crops is minimum (1187.6 MJ/ha) for moth bean and maximum (1261.9 MJ/ha) for cluster bean, while for irrigated crops, it is minimum (2847.3 MJ/ha) for moth bean, and maximum (12,809.6 MJ/ha) for groundnut. The average specific energy for cultivation of cluster bean (rain fed), cluster bean (irrigated), moth bean (rain fed), moth bean (irrigated) and groundnut were 11.7, 7.5, 7.7, 7.4 and 11.2 MJ/ha, respectively. Operation wise, the energy consumed for Rabi crops is minimum (3855.6 MJ/ha) for rocket salad followed by 4779.4 MJ/ha for mustard, 4845.2 MJ/ha for gram and maximum (7953.2 MJ/ha) for wheat. The average specific energy for cultivation of wheat, gram, mustard and rocket salad were 11.4, 16.5, 13.2 and 13.7 MJ/ha, respectively. The average values of estimated energy ratio for cluster bean (rain fed), cluster bean (irrigated), moth bean (rain fed), moth bean (irrigated) and groundnut were 2.1, 0.5, 3.4, 3.5 and 3.0, respectively. This suggests that the moth bean crop is more remunerating to the farmers in Kharif as compared to cluster bean

  8. Iodine-123 in Western Europe

    International Nuclear Information System (INIS)

    The major object of this panel was to obtain information on the state of art of Iodine-123 production in Western Europe. Technical, medical and organizational problems were discussed extensively during the one-day meeting and a stimulating exchange of information between the various 123I-producers and users has been initiated. Some specific examples of medical application were also included in order to get a feeling of the degree of acceptance by the medical community and the demand for this isotope. The meeting clearly demonstrated the great demand for this isotope but it also showed that the present rate of production is well below the demand. In order to fill this gap, not only further technical development is needed but also the organizational question of distribution has to be solved, perhaps within a network of collaborating cyclotrons, a task which is considerably more difficult in Western Europe than in the USA. (orig./HP)

  9. Pottery ethnoarchaeology in Western Ethiopia

    OpenAIRE

    González Ruibal, Alfredo

    2005-01-01

    The results of three ethnoarchaeological field seasons carried out among the Berta, Gumuz, Mao and Kwama of western Ethiopia are presented here. Fieldwork focused on the gathering of general data on the material culture of Benishangul- Gumuz, and particularly on pottery and vernacular architecture. The data relating to production, distribution and consumption of pottery are addressed in this article. The peoples studied are organised on egalitarian lines and practise a slash-and-burn agricult...

  10. Fire in Western Forest Ecosystems

    OpenAIRE

    Arno, Stephen F

    2000-01-01

    Major forest types that are characterized by nonlethal understory fire regimes include those where ponderosa pine or Jeffrey pine has been a major component either as a fire-maintained seral type or as the self-perpetuating climax (table 5-1). This includes extensive areas throughout the Western United States from northern Mexico to southern British Columbia, Canada (Little 1971). Also, sizeable areas of open woodlands dominated by Oregon white oak, California black oak, blue oak, or Digger p...

  11. Landcover classification: western Kenya, 2010.

    OpenAIRE

    Wardrop, Nicola A.

    2015-01-01

    Landcover classifications were produced for an area of western Kenya based on ASTER (15m spatial resolution) and Landsat (30m spatial resolution) imagery from 2010 and 2011. The land cover classification was carried out in a hierarchical manner, resulting in two overarching classes (a) vegetated land (versus built up and bare ground) and (b) flooding land (versus non-flooding land); and five lower level classes (c) agricultural land and grassland, (d) swamp, (e) trees and shrubs, (f) rice and...

  12. Comparative characteristics of anatomical and morphological adaptations of plants of two subgenera Haworthia Duval to arid environmental conditions

    Directory of Open Access Journals (Sweden)

    Nataliya Volodymyrivna Nuzhyna

    2015-03-01

    Full Text Available This paper presents the comparative anatomical and morphological characteristics of plants of two subgenera: Haworthia and Hexangularis. The study revealed two different strategies of adaptation to arid conditions of the growth of different subgenera of the genus Haworthia. Plants of the subgenus Haworthia adapted to arid conditions by increasing the accumulation of water, the presence of “windows”, a smaller stoma size, and a thinner outer wall of the epidermis cells. On the other hand, plants of the subgenus Hexangularis adapted to arid conditions by reducing overheating and transpiration as well as by the presence of papillae and a thickened outer wall of the epidermis cells.

  13. Hydrocarbon prospectivity in Western Greece

    Energy Technology Data Exchange (ETDEWEB)

    Maravelis, Angelos; Makrodimitras, George; Zelilidis, Avraam [Patras Univ. (Greece). Lab. of Sedimentology

    2012-06-15

    The geology of Western Greece is dominated by the most external zones of the Hellenide fold-and-thrust belt, namely the Pre-Apulian (or Paxoi) and Ionian zones. With Western Greece and Albania having undergone, in broad terms, similar geological histories, also the hydrocarbon potentials of both areas may be compared. Likewise, the hydrocarbon potential of Italy's Apulian Platform, adjoining in the westerly offshore, may serve as an analogue. Three basin types within Western Greece that deserve hydrocarbon exploration have been examined and are grouped, correlated to major tectonic features, namely foreland (Ionian thrusts' foreland basin), piggy-back (Ionian thrusts' back-arc basin) and strike-slip basins. Additionally, strike-slip basins are further subdivided into the basin north of the Borsh-Khardhiqit strike-slip fault and the Preveza basin, north of Cephalonia transfer fault. Their filling histories suggest the occurrence of Mesozoic carbonate plays and Oligocene/Miocene sandstone plays both for oil and gas.

  14. Buddha philosophy and western psychology.

    Science.gov (United States)

    Aich, Tapas Kumar

    2013-01-01

    Four noble truths as preached by Buddha are that the life is full of suffering (Duhkha), that there is a cause of this suffering (Duhkha-samudaya), it is possible to stop suffering (Duhkha-nirodha), and there is a way to extinguish suffering (Duhkha-nirodha-marga). Eight fold Path (astangika-marga) as advocated by Buddha as a way to extinguish the sufferings are right views, right resolve/aspiration, right speech, right action/conduct, right livelihood, right effort right mindfulness and right concentration. Mid-twentieth century saw the collaborations between many psychoanalysts and Buddhist scholars as a meeting between "two of the most powerful forces" operating in the Western mind. Buddhism and Western Psychology overlap in theory and in practice. Over the last century, experts have written on many commonalities between Buddhism and various branches of modern western psychology like phenomenological psychology, psychoanalytical psychotherapy, humanistic psychology, cognitive psychology and existential psychology. Orientalist Alan Watts wrote 'if we look deeply into such ways of life as Buddhism, we do not find either philosophy or religion as these are understood in the West. We find something more nearly resembling psychotherapy'. Buddha was a unique psychotherapist. His therapeutic methods helped millions of people throughout the centuries. This essay is just an expression of what little the current author has understood on Buddha philosophy and an opportunity to offer his deep tribute to one of the greatest psychotherapists the world has ever produced! PMID:23858249

  15. Western Transbaikalia (South East Siberia): desertification from the past towards present

    Science.gov (United States)

    Alexeeva, Nadezhda; Erbajeva, Margarita A.; Khenzykhenova, Fedora I.

    2010-05-01

    laguriforme, appearance of the genus Equus. The Middle Pleistocene of the Western Transbaikalia is characterized by further changing of the climate towards arid. Significant changes in small mammal associations took place. The typical inhabitants of semideserts and deserts such as Meriones and Ellobius appeared in the fauna. This evidence as well as an increasing of frequency of Eolagurus and Allactaga and decrease of ochotonids and ground squirrels have indicating the strengthening of the climate aridization. In the region dry steppes, semideserts and deserts wide spread at that time which is evidenced as well by the data of plant community. The Transbaikalian faunas of that time with the predominance of the Central Asian elements and vegetation resembled the recent condition of south Mongolia. To the Late Pleistocene the paleoenvironment of studied region have changed towards more or less periglacial. Dry steppes with the dominance of wormwood plants widely expanded in the region. The following intensive cooling of the climate led to the further reorganization of the mammal community and vegetation. The fauna is represented by the modern species however the distribution area of some of them were extended far to the North-East, far beyond their present limits. During whole Late Pleistocene the territory of Western Transbaikalia were occupied by open landscapes dwellers. Because of arid climate and environment was predominant in Transbaikalia the species composition of the faunas of cold and warm periods in total are almost common? They differ mainly by the quantity ratio of taxa. By contrast the adjacent contemporaneous Prebaikalian fauna included the taxa which were ecologically mixed and this fauna is named as non-analogue,, or tundra-forest-steppe, or mammoth fauna. The comparison of mammal faunas of these two regions show that they differ each other by the predominance of the Central-Asian elements in Transbaiaklian faunas and European-Siberian one in Prebaikalian.

  16. The Western Denmark Cardiac Computed Tomography Registry

    DEFF Research Database (Denmark)

    Nielsen, Lene Hüche; Nørgaard, Bjarne Linde; Tilsted, Hans Henrik;

    2015-01-01

    BACKGROUND: As a subregistry to the Western Denmark Heart Registry (WDHR), the Western Denmark Cardiac Computed Tomography Registry (WDHR-CCTR) is a clinical database established in 2008 to monitor and improve the quality of cardiac computed tomography (CT) in Western Denmark. OBJECTIVE: We...

  17. Genetic and environmental characterization of Abies alba Mill. populations at its western rear edge

    Directory of Open Access Journals (Sweden)

    Sancho-Knapik, D.

    2014-12-01

    Full Text Available The genetic structure of ten Abies alba populations at the western rear edge in the Spanish Pyrenees was characterized and compared with two German populations, looking for the role of climatic factors in the fir decline. Growth, defoliation, aridity and cumulative summer water deficit summer were also characterized. Spanish populations show a lower genetic diversity and a high genetic differentiation than German ones, mainly established by an East (higher diversity-West (lower diversity gradient. The three defoliated populations are the western ones, with higher summer aridity. Contrastingly, the southern population (Guara shows climatic variables close to western sites but without defoliation and with a higher genetic diversity, indicating a possible adaptation to the sub-Mediterranean conditions. Silver fir in the Spanish Pyrenees constitutes a “stable” rear edge because of their isolation, small sized and small genetic diversity. Western Pyrenean sites subjected to dryer conditions and presenting lower genetic diversity are prone to drought-induced mortality in the context of global warming.Se ha caracterizado la estructura genética de diez poblaciones de Abies alba en la retaguardia occidental de su distribución en el Pirineo español en comparación con dos poblaciones de Alemania, buscando la influencia de factores climáticos en el decaimiento del abeto. También se caracterizó crecimiento, defoliación, aridez y déficit acumulado de agua durante el verano. Las poblaciones españolas mostraron una menor diversidad genética y una mayor diferenciación genética que las poblaciones alemanas, establecida principalmente a través de un eje Este (mayor diversidad-Oeste (menor diversidad. Las tres poblaciones con defoliación son las del suroeste, con mayor aridez estival. Por el contrario, la población más meridional (Guara muestra variables climáticas cercanas a estas poblaciones del suroeste pero sin defoliación y con mayor

  18. Rainfall simulations as a tool for quantification of soil erosion processes caused by the trampling of sheep and goats in semi-arid and arid landscapes

    Science.gov (United States)

    Ruthenberg, Jonas; Tumbrink, Jonas; Wilms, Tobias; Peter, Klaus Daniel; Wirtz, Stefan; Ries, Johannes B.

    2015-04-01

    As there is a massive increase of livestock husbandry in semi-arid and arid landscapes, the investigation of trampling-induced soil erosion has become indispensable for a better understanding of erosive processes such as loosening and translocation of sediment, as well as the genesis of rill erosion and gully systems. Our work will support other studies focusing on desertification and land-use changes in the investigated landscapes. Up to this date, research on livestock-induced soil erosion, even in relation to other erosion processes such as aeolian and fluvial/pluvial sediment translocation, is very scarcely found in literature. The presented study on trampling-induced soil erosion by sheep and goats in arid and semi-arid landscapes aims to create a general understanding, an estimation and quantification of the influencing factors of these erosive processes. Within this study, we present the first results of several field rainfall experiments on rock fragment translocation as well as loosening and transportation of coarse and fine sediment depending on the motion sequence and the individual weight, size, and hoof beat of the animals. Furthermore, we conducted additional experiments to investigate the trampling-induced erosion processes for various other sediments, especially those in the range of clay, silt, and sand. To do so, we used a specially designed test plot, equipped with sediment traps on each side. For a clear and reliable analysis of the measured parameters, univariate as well as multivariate statistical methods have been used. For all field methods, we developed relevant statements concerning flock size. The rock fragment translocation experiments done so fare have shown that a flock of 45 sheep or goats moved 87 % of 320 spread out rock fragments with a mean translocation distance of 0.123 m when trampling across a test plot of 3.2 m^2. Besides that we found out that the soil surface was worked up in a way that the loosened fine sediment proved to

  19. Nutrient and water management practices for increasing crop production in rainfed arid/semi-arid areas. Proceedings of a coordinated research project

    International Nuclear Information System (INIS)

    The world's population is expected to reach eight billion by the year 2025, putting greater pressure on world food security, especially in developing countries where major population increases is expected to occur. In meeting the increasing demand for food, rainfed agriculture will continue to play a major role. More than 65% of cereal croplands worldwide are rainfed, accounting for 58% of world cereal production. Moreover, with the decreasing availability of irrigation water for agriculture, there is an increased need for enhancing crop productivity under rainfed conditions. Currently, irrigation accounts for around 70% of water withdrawals worldwide and 90% in low-income developing countries, but due to rapidly increasing domestic and industrial demands for water in many developing countries, serious limitations to irrigated agriculture are foreseen. Increasing crop productivity in arid and semi-arid areas is widely recognized as difficult. This is mainly due to highly erratic and low rainfall as well as degraded soils deficient in plant nutrients. To meet the increasing demand for food, farmers in many developing countries have expanded rainfed agriculture into marginal lands that are susceptible to environmental degradation, particularly soil erosion. Nutrient mining is a common application of adequate amounts of fertilizers to replenish nutrient uptake by crops and losses but is not a viable option for most resource-poor farmers in these regions. As a result, crop productivity of rainfed regions is low. For example, cereal yields in rainfed areas of developing countries rarely exceed 1.5 t ha-1, less than half those of rainfed cereals in developed countries. Nevertheless, there is some evidence that crop yields in these regions can be profitably increased and yield variation decreased with a combination of careful management of natural resources and low inputs of chemical fertilizers. Since nearly two-thirds of the rural population of developing countries live

  20. Facies-architecture of fossil arid siliciclastic depositional systems as outcrop analogue for Rotliegend reservoirs. Literature study; Faziesarchitektur fossiler arid-klastischer Ablagerungsraeume als Rotliegend-Reservoiranalog. Literaturstudie

    Energy Technology Data Exchange (ETDEWEB)

    Irmen, A.

    1999-08-01

    In this project a literature-based study was carried out in order to document the facies-architecture of siliciclastic sediments from arid environments and to investigate their suitability as outcrop-analogues for the strata of the Southern Permian Basin. The report resulting from this investigation presents possible analogues and case-studies. Three Formations (Flechtingen Sandstone, Corrie Sandstone and Cedar Mesa Sandstone of the Cutler Group) are especially well suited to serve as outcrop analogue for the 'Rotliegend' Sediments of the Southern Permian Basin. Possible analogues are documented at various scales, ranging from bed-scale to formation scale. Also, special attention was paid to general trends and what factors control them. To make a comparison of Formations from different settings possible, criteria were elaborated to qualify the relevant controlling factors. The catalog itself is preceded by a comprehensive preface, that introduces to the subject and points out the connection between the primary sediment fabric and its petrophysical properties. (orig.) [German] Im Rahmen dieses DGMK Forschungsvorhabens wurde eine Literaturstudie durchgefuehrt, welche die Faziesarchitektur fossiler arid-klastischer Sedimente darstellt und auf ihre Eignung als Rotliegend-Reservoiranalog untersucht. Die vorliegende Dokumentation stellt verschiedene moegliche Analoge und Fallbeispiele dar, wobei drei Abfolgen als besonders geeignet erscheinen. Es wurden Kriterien erarbeitet, die relevante Kontrollfaktoren qualifizieren, um einen Vergleich verschiedener arid-klastischer Sedimentationsraeume zu ermoeglichen. Die Bandbreite der Darstellung moeglicher Analoge umfasst das gesamte Spektrum vom Gefuegemassstab bis hin zu genetischen Einheiten und beleuchtet die jeweiligen Steuerungsfaktoren der Ablagerung. Der eigentlichen Dokumentation wurde eine umfassende Einleitung vorangestellt, welche in die Thematik einfuehrt und Zusammenhaenge zwischen primaerem