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Sample records for clear lake region

  1. Hydrogeochemical evaluation of conventional and hot dry rock geothermal resource potential in the Clear Lake region, California

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.

    1993-05-01

    Chemistry, stable isotope, and tritium contents of thermal/mineral waters in the Clear Lake region were used to evaluate conventional and hot dry rock (HDR) geothermal potential for electrical generation. Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connate types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connate (generic) end-members. The latter end-member has enriched {delta}D as well as enriched {delta}{sup 18}O, from typical high-temperature geothermal reservoir waters. Tritium data indicate most Clear Lake region waters are mixtures of old and young fluid components. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is {le}150{degree}C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures {le}150{degree}C (except for Sulphur Bank mine). HDR technologies are probably the best way to commercially exploit the known high-temperatures existing beneath the Clear Lake region particularly within and near the main Clear Lake volcanic field.

  2. Geochemistry of thermal/mineral waters in the Clear Lake region, California, and implications for hot dry rock geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.; Mansfield, J.

    1993-02-01

    Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connote types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast, ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connote end-members. The latter end-member has enriched [delta]D as well as enriched d[sup l8]O, very different from typical high-temperature geothermal reservoir waters. Tritium data and modeling of ages indicate most Clear Lake region waters are 500 to > 10,000 yr., although mixing of old and young components is implied by the data. The age of end-member connate water is probably > 10,000 yr. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is [le] 150[degrees]C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures [le] 150[degrees]C (except for Sulphur Bank Mine). Hot dry rock technologies are the best way to commercially exploit the known high temperatures existing beneath the Clear Lake region, particularly within the main Clear Lake volcanic field.

  3. Gravity and magnetic studies of the Geysers-Clear Lake geothermal region, California, USA

    Science.gov (United States)

    Isherwood, William F.

    1976-01-01

    Gravity and magnetic fields in The Geysers-Clear Lake region are interpreted in relation to the known geology and other available geophysical data. New gravity data provide additional detail with the area of geothermal steam production. Computer techniques were used for removal of the regional gravity field, anomaly enhancement, and modeling subsurface structures. The gravity field was separated into three components: (1) a regional field presumed to be due to deep crustal structure related to the continental margin; (2) a residual gravity low of approximately 30 mgal centered over Mount Hannah and having an approximate diameter of 20 km, which is caused, according to our model, by a magma chamber whose top lies within 10 km of the surface; and (3) a closed residual low over the original steam production field. This low is probably related to effects within 1.5 km of the surface and was modeled as a steam-saturated reservoir structure. Local magnetic highs correlate with surface outcrops of serpentinite and relief on the volcanic rocks. Upward continuation of the aeromagnetic data suggests that the serpentinite body along the Collayomi fault may extend to a depth of more than 3 km near Boggs Mountain, but that other serpentinite bodies are probably more shallow. A long-wavelength magnetic high (centered at ~39°03'N 122°33'W) and a magnetic low (centered at ~38°:43'N 122°47'W) give half-width depth estimates of about 10 km. The center of the Mount Hannah gravity low lies in an area between these features and appears devoid of deep magnetic expression.

  4. Carbon isotope systematics and CO2 sources in The Geysers-Clear Lake region, northern California, USA

    Science.gov (United States)

    Bergfeld, D.; Goff, F.; Janik, C.J.

    2001-01-01

    Carbon isotope analyses of calcite veins, organic carbon, CO2 and CH4 from 96 rock and 46 gas samples show that metamorphic calcite veins and disseminated, organically-derived carbon from Franciscan Complex and Great Valley Sequence rocks have provided a primary carbon source for geothermal fluids during past and present hydrothermal activity across The Geysers-Clear Lake region. The stable isotope compositions of calcite veins vary widely on a regional scale, but overall they document the presence of 13C-poor fluids in early subduction-related vein-precipitating events. ??13C values of calcite veins from the SB-15-D corehole within The Geysers steam field indicate that carbon-bearing fluids in the recent geothermal system have caused the original diverse ??13C values of the veins to be reset. Across The Geysers-Clear Lake region the carbon isotope composition of CO2 gas associated with individual geothermal reservoirs shows a general increasing trend in ??13C values from west to east. In contrast, ??13C values of CH4 do not exhibit any spatial trends. The results from this study indicate that regional variations in ??13C-CO2 values result from differences in the underlying lithologies. Regional CO2 contains significant amounts of carbon related to degradation of organic carbon and dissolution of calcite veins and is not related to equilibrium reactions involving CH4. CO2 from degassing of underlying magma chambers is not recognizable in this region. Published by Elsevier Science Ltd on behalf of CNR.

  5. Field Trip Guide to Serpentinite, Silica-Carbonate Alteration, and Related Hydrothermal Activity in the Clear Lake Region, California

    Energy Technology Data Exchange (ETDEWEB)

    Fraser Goff; George Guthrie

    1999-06-01

    This guide is designed to familiarize scientists with the geology, structure, alteration, and fluids typical of California serpentinites for purposes of carbon dioxide sequestration (Lackner et al., 1995). Goff et al. (1997) and Goff and Lackner (1998) describe the geology and geochemistry of some of the serpentinites from this area. Mechanisms of silica-carbonate alteration were outlined by Barnes et al. (1973). Donnelly-Nolan et al. (1993) most recently reviewed relations between regional hydrothermal alteration and Quarternary volcanic activity. Stanley et al. (1998) summarized geophysical characteristics of the region.

  6. A Mass balance mercury budget for a mine-dominated lake: Clear Lake, California

    Science.gov (United States)

    Suchanek, T.H.; Cooke, J.; Keller, K.; Jorgensen, S.; Richerson, P.J.; Eagles-Smith, C. A.; Harner, E.J.; Adam, D.P.

    2009-01-01

    The Sulphur Bank Mercury Mine (SBMM), active intermittently from 1873-1957 and now a USEPA Superfund site, was previously estimated to have contributed at least 100 metric tons (105 kg) of mercury (Hg) into the Clear Lake aquatic ecosystem. We have confirmed this minimum estimate. To better quantify the contribution of the mine in relation to other sources of Hg loading into Clear Lake and provide data that might help reduce that loading, we analyzed Inputs and Outputs of Hg to Clear Lake and Storage of Hg in lakebed sediments using a mass balance approach. We evaluated Inputs from (1) wet and dry atmospheric deposition from both global/regional and local sources, (2) watershed tributaries, (3) groundwater inflows, (4) lakebed springs and (5) the mine. Outputs were quantified from (1) efflux (volatilization) of Hg from the lake surface to the atmosphere, (2) municipal and agricultural water diversions, (3) losses from out-flowing drainage of Cache Creek that feeds into the California Central Valley and (4) biotic Hg removal by humans and wildlife. Storage estimates include (1) sediment burial from historic and prehistoric periods (over the past 150-3,000 years) from sediment cores to ca. 2.5m depth dated using dichloro diphenyl dichloroethane (DDD), 210Pb and 14C and (2) recent Hg deposition in surficial sediments. Surficial sediments collected in October 2003 (11 years after mine site remediation) indicate no reduction (but a possible increase) in sediment Hg concentrations over that time and suggest that remediation has not significantly reduced overall Hg loading to the lake. Currently, the mine is believed to contribute ca. 322-331 kg of Hg annually to Clear Lake, which represents ca. 86-99% of the total Hg loading to the lake. We estimate that natural sedimentation would cover the existing contaminated sediments within ca. 150-300 years. ?? 2008 Springer Science+Business Media B.V.

  7. Global Lakes Sentinel Services: Evaluation of Chl-a Trends in Deep Clear Lakes

    Science.gov (United States)

    Cazzaniga, Ilaria; Giardino, Claudia; Bresciani, Mariano; Poser, Kathrin; Peters, Steef; Hommersom, Annelies; Schenk, Karin; Heege, Thomas; Philipson, Petra; Ruescas, Ana; Bottcher, Martin; Stelzer, Kerstin

    2016-08-01

    The aim of this study is the analysis of trend in the trophic level evolution in clear deep lakes which, being characterised by good quality state, are important socio- economic resources for their regions. The selected lakes are situated in Europe (Garda, Maggiore, Constance and Vättern), North America (Michigan) and Africa (Malawi and Tanganyika) and cover a range of eco- regions (continental, perialpine, boreal, rift valley) distributed globally.To evaluate trophic level tendency we mainly focused on chlorophyll-a concentrations (chl-a) which is a direct proxy of trophic status. The chl-a concentrations were obtained from 5216 cloud-free MERIS imagery from 2002 to 2012.The 'GLaSS RoIStats tool' available within the GLaSS project was used to extract chl-a in a number of region of interests (ROI) located in pelagic waters as well as some few other stations depending on lakes morphology. For producing the time-series trend, these extracted data were analysed with the Seasonal Kendall test.The results overall show almost stable conditions with a slight increase in concentration for lakes Maggiore, Constance, and the Green Bay of Lake Michigan; a slight decrease for lakes Garda and Tanganyika and absolutely stable conditions for lakes Vättern and Malawi.The results presented in this work show the great capability of MERIS to perform trend tests analysis on trophic status with focus on chl-a concentration. Being chl-a also a key parameter in water quality monitoring plans, this study also supports the managing practices implemented worldwide for using the water of the lakes.

  8. Clearing lakes. An ecosystem approach to the restoration and management of shallow lakes in the Netherlands.

    NARCIS (Netherlands)

    Hosper, H.

    1997-01-01

    In the 1950 s and 1960 s, most shallow lakes in the Netherlands shifted from macrophyte-dominated clear water lakes, towards algae-dominated turbid water lakes. Eutrophication, i.e. increased nutrient loading, is the main cause of the deterioration of the lake ecosystems. Other perturbations, such a

  9. Direct heat applications of geothermal energy in The Geysers/Clear Lake region. Volume I. Geotechnical assessment, agribusiness applications, socioeconomic assessment, engineering assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Discussion is presented under the following section headings: background and some technical characteristics of geothermal resources; geology and geohydrology, geophysics, and, conclusions regarding availability of geothermal energy for nonelectric uses; agricultural assessment of Lake County, site assessment for potential agricultural development, analysis of potential agricultural applications, special application of low cost geothermal energy to algae harvesting, development of an integrated agribusiness, geothermal complex in Lake County, analysis of individual enterprises, and, recommendations for subsequent work; demographic characteristics, economic condition and perspective of Lake County, economic impact of geothermal in Lake County, social and economic factors related to geothermal resource development, socioeconomic impact of nonelectric uses of geothermal energy, and, identification of direct heat applications of geothermal energy for Lake County based on selected interviews; cost estimate procedure, example, justification of procedure, and, typical costs and conclusions; and, recommended prefeasibility and feasibility studies related to construction of facilities for nonelectric applications of geothermal resource utilization. (JGB)

  10. Great Lakes' regional climate regimes

    Science.gov (United States)

    Kravtsov, Sergey; Sugiyama, Noriyuki; Roebber, Paul

    2016-04-01

    We simulate the seasonal cycle of the Great Lakes' water temperature and lake ice using an idealized coupled lake-atmosphere-ice model. Under identical seasonally varying boundary conditions, this model exhibits more than one seasonally varying equilibrium solutions, which we associate with distinct regional climate regimes. Colder/warmer regimes are characterized by abundant/scarce amounts of wintertime ice and cooler/warmer summer temperatures, respectively. These regimes are also evident in the observations of the Great Lakes' climate variability over recent few decades, and are found to be most pronounced for Lake Superior, the deepest of the Great Lakes, consistent with model predictions. Multiple climate regimes of the Great Lakes also play a crucial role in the accelerated warming of the lakes relative to the surrounding land regions in response to larger-scale global warming. We discuss the physical origin and characteristics of multiple climate regimes over the lakes, as well as their implications for a longer-term regional climate variability.

  11. Use of clear lake as standard reflectors for atmospheric measurement

    Science.gov (United States)

    Ahern, F. J.; Goodenough, D. G.; Jain, S. C.; Rao, V. R.; Rochon, G.

    1977-01-01

    A method is proposed for using clear lakes as dark backgrounds against which the atmospheric path radiance can be determined from satellite observations. If the path radiance can be determined to sufficient accuracy, the atmospheric extinction can be inferred with suitable radiative transfer models. An extensive program of observation was made to determine the magnitude and variability of the various contributors to the total radiance observed by a satellite. It is shown that the volume and surface reflectance contributions (in the absence of sunglint) are small, constant, and can be modeled accurately enough to make these an insignificant source of error. The sunglint radiance observed in this investigation may be a significant source of error. It is shown that atmospheric extinction can be inferred from the path radiance observation after systematic differences between the model and observations are removed.

  12. Restoring lakes by using artificial plant beds: habitat selection of zooplankton in a clear and a turbid shallow lake

    DEFF Research Database (Denmark)

    Schou, Majbritt Overgård; Risholt, Casper; Lauridsen, Torben L.;

    2009-01-01

    1. Return of large-bodied zooplankton populations is of key importance for creating a shift from a turbid to a clear-water state in shallow lakes after a nutrient loading reduction. In temperate lakes, recovery is promoted by submerged macrophytes which function as a daytime refuge for large...... in lake restoration, we followed the day–night habitat choices of zooplankton throughout summer in a clear and a turbid lake. Observations were made in the pelagic and littoral zones and in APB in the littoral representing three different plant densities (coverage 0%, 40% and 80%). 3. In the clear lake...... overall more equally distributed between the five habitats. Ceriodaphnia was proportionally more abundant in the APB during most of the season. Cyclopoids were more abundant in the high APB during day but were equally distributed between the five habitats during night. 4. In the turbid lake, however...

  13. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    Science.gov (United States)

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

    2016-01-01

    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  14. Clear Lake National Wildlife Refuge : Klamath Basin National Wildlife Refuges : Annual Narrative Report : Calendar Year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Clear Lake National Wildlife Refuge outlines Refuge accomplishments during the 1981 calendar year. The report begins with a summary...

  15. The Life Cycle of Mercury Within the Clear Lake Aquatic Ecosystem: From Ore to Organism

    Science.gov (United States)

    Suchanek, T. H.; Suchanek, T. H.; Nelson, D. C.; Nelson, D. C.; Zierenberg, R. A.; King, P.; King, P.; McElroy, K.; McElroy, K.

    2001-12-01

    Clear Lake (Lake County) is located in the geologically active Clear Lake volcanics mercury (Hg) bearing Franciscan formation within the Coast Range of California, which includes over 300 abandoned Hg mines and prospects. Intermittent mining at the Sulphur Bank Mercury Mine (from 1872-1957), now a USEPA SuperFund site, has resulted in approximately 100 metric tonnes of Hg being deposited into the aquatic ecosystem of Clear Lake, with sediment concentrations of total-Hg as high as 650 mg/kg (parts per million = ppm) near the mine, making Clear Lake one of the most Hg contaminated lakes in the world. As a result, largemouth bass and other top predatory fish species often exceed both the Federal USFDA recommended maximum recommended concentrations of 1.0 ppm and the State of California level of 0.5 ppm. Acid rock drainage leaches Hg and high concentrations of sulfate from the mine site through wasterock and subsurface conduits through subsediment advection and eventually upward diffusion into lake sediments and water. When mineral-laden pH 3 fluids from the mine mix with Clear Lake water (pH 8), an alumino-silicate precipitate (floc) is produced that promotes the localized production of toxic methyl Hg. Floc "hot spots" in sediments near the mine exhibit low pH, high sulfate, anoxia and high organic loading which create conditions that promote Hg methylation by microbial activity, especially in late summer and fall. Wind-driven currents transport methyl-Hg laden floc particles throughout Clear Lake, where they are consumed by plankton and benthic invertebrates and bioaccumulated throughout the food web. While Clear Lake biota have elevated concentrations of methyl-Hg, they are not as elevated as might be expected based on the total Hg loading into the lake. A science-based management approach, utilizing over 10 years of data collected on Hg cycling within the physical and biological compartments of Clear Lake, is necessary to affect a sensible remediation plan.

  16. Thermal modeling of the Clear Lake magmatic system, California: Implications for conventional and hot dry rock geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Stimac, J.; Goff, F.; Wohletz, K.

    1997-06-01

    The combination of recent volcanism, high heat flow ({ge} HFU or 167 mW/m{sup 2}), and high conductive geothermal gradient (up to 120{degree} C/km) makes the Clear Lake region of northern California one of the best prospects for hot dry rock (HDR) geothermal development in the US. The lack of permeability in exploration wells and lack of evidence for widespread geothermal reservoirs north of the Collayomi fault zone are not reassuring indications for conventional geothermal development. This report summarizes results of thermal modeling of the Clear Lake magmatic system, and discusses implications for HDR site selection in the region. The thermal models incorporate a wide range of constraints including the distribution and nature of volcanism in time and space, water and gas geochemistry, well data, and geophysical surveys. The nature of upper crustal magma bodies at Clear Lake is inferred from studying sequences of related silicic lavas, which tell a story of multistage mixing of silicic and mafic magma in clusters of small upper crustal chambers. Thermobarometry on metamorphic xenoliths yield temperature and pressure estimates of {approximately}780--900 C and 4--6 kb respectively, indicating that at least a portion of the deep magma system resided at depths from 14 to 21 km (9 to 12 mi). The results of thermal modeling support previous assessments of the high HDR potential of the area, and suggest the possibility that granitic bodies similar to The Geysers felsite may underlie much of the Clear Lake region at depths as little as 3--6 km. This is significant because future HDR reservoirs could potentially be sited in relatively shallow granitoid plutons rather than in structurally complex Franciscan basement rocks.

  17. Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes.

    Science.gov (United States)

    Mladenov, N; Sommaruga, R; Morales-Baquero, R; Laurion, I; Camarero, L; Diéguez, M C; Camacho, A; Delgado, A; Torres, O; Chen, Z; Felip, M; Reche, I

    2011-01-01

    Remote lakes are usually unaffected by direct human influence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may influence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this influence, we evaluate factors related to aerosol deposition, climate, catchment properties, and microbial constituents in a global dataset of 86 alpine and polar lakes. We show significant latitudinal trends in dissolved organic matter quantity and quality, and uncover new evidence that this geographic pattern is influenced by dust deposition, flux of incident ultraviolet radiation, and bacterial processing. Our results suggest that changes in land use and climate that result in increasing dust flux, ultraviolet radiation, and air temperature may act to shift the optical quality of dissolved organic matter in clear, alpine lakes.

  18. The Great Lakes Regional Stroke Network Experience

    OpenAIRE

    Bray Hedworth, Angela; Smith, Cassidy S

    2006-01-01

    Stroke is a leading cause of disability and the third leading cause of death among adults in the United States and in the Great Lakes states of Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin. The Great Lakes Regional Stroke Network was created to enhance collaboration and coordination among the Great Lakes states to reduce the burden of stroke and stroke-related disparities associated with race, sex, and geography. Three priorities were identified for reducing the effects of stro...

  19. Do zooplankton contribute to an ultraviolet clear-water phase in lakes?

    NARCIS (Netherlands)

    Williamson, C.E.; Lange, de H.J.; Leech, D.M.

    2007-01-01

    Seasonal increases in the ultraviolet (UV) transparency of the surface waters of an oligotrophic lake in Pennsylvania suggest that clear-water phase (CWP) events similar to those previously observed for visible light also exist for the potentially damaging UV wavelengths. Seasonal increases in zoopl

  20. Characterizing seasonal and diel vertical movement and habitat use of lake whitefish (Coregonus clupeaformis) in Clear Lake, Maine

    Science.gov (United States)

    Zydlewski, Joseph; Gorsky, Dimitry; Balsey, David

    2016-01-01

    Seasonal and daily vertical activity of lake whitefish Coregonus clupeaformis was studied in Clear Lake, Maine (253 ha), using acoustic telemetry from November 2004 to June 2009. Twenty adult lake whitefish were tagged with acoustic tags that had either a depth sensor or both depth and temperature sensors to assess vertical habitat use at a seasonal and daily resolution. Vertical habitat selection varied seasonally and was strongly influenced by temperature. Between December and April, when the lake was covered with ice, surface temperature was below 2°C and tagged individuals occupied deep areas of the lake (∼15 m). After ice-out, fish ascended into shallow waters (∼5 m), responding to increased water temperature and possibly to greater foraging opportunity. When surface water temperatures exceeded 20°C, fish descended below the developing thermocline (∼9 m), where they remained until surface temperatures fell below 20°C; fish then ascended into shallower depths, presumably for feeding and spawning. Through the winter, fish remained in thermal habitats that were warmer than the surface temperatures; in the summer, they selected depths with thermal habitats below 15°C. Though the amplitude varied greatly across seasons, lake whitefish displayed a strong diurnal pattern of activity as measured by vertical velocities. Fish were twofold more active during spring, summer, and fall than during winter. Lake whitefish exhibited diel vertical migrations, rising in the water column during nighttime and occupying deeper waters during the day. This pattern was more pronounced in the spring and fall and far less prominent during winter and summer. The strong linkage between temperature and habitat use may limit the current range of lake whitefish and may be directly impacted by climatic change.

  1. Seasonal distribution, aggregation, and habitat selection of common carp in Clear Lake, Iowa

    Science.gov (United States)

    Penne, C.R.; Pierce, C.L.

    2008-01-01

    The common carp Cyprinus carpio is widely distributed and frequently considered a nuisance species outside its native range. Common carp are abundant in Clear Lake, Iowa, where their presence is both a symptom of degradation and an impediment to improving water quality and the sport fishery. We used radiotelemetry to quantify seasonal distribution, aggregation, and habitat selection of adult and subadult common carp in Clear Lake during 2005-2006 in an effort to guide future control strategies. Over a 22-month period, we recorded 1,951 locations of 54 adults and 60 subadults implanted with radio transmitters. Adults demonstrated a clear tendency to aggregate in an offshore area during the late fall and winter and in shallow, vegetated areas before and during spring spawning. Late-fall and winter aggregations were estimated to include a larger percentage of the tracked adults than spring aggregations. Subadults aggregated in shallow, vegetated areas during the spring and early summer. Our study, when considered in combination with previous research, suggests repeatable patterns of distribution, aggregation, and habitat selection that should facilitate common carp reduction programs in Clear Lake and similar systems. ?? Copyright by the American Fisheries Society 2008.

  2. Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

    Science.gov (United States)

    Chen, W.; Doko, T.; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

    2014-12-01

    The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the glacier retreat. New glacial lakes are formed, and a number of them have expanded in the Everest region of the Himalayas. This paper focuses on the two glacial lakes which are Imja Lake, located at the southern slope, and Rongbuk Lake, located at the northern slope in the Mt. Everest region, Himalaya to present the spatio-temporal changes from 1976 to 2008. Topographical conditions between two lakes were different (Kruskal-Wallis test, p Lake was located at 623 m higher than Imja Lake, and radiation of Rongbuk Lake was higher than the Imja Lake. Although size of Imja Lake was larger than the Rongbuk Lake in 2008, the growth speed of Rongbuk Lake was accelerating since 2000 and exceeds Imja Lake in 2000-2008. This trend of expansion of Rongbuk Lake is anticipated to be continued in the 21st century. Rongbuk Lake would be the biggest potential risk of glacial lake outburst flood (GLOF) at the Everest region of Himalaya in the future.

  3. Preliminary juvenile Lost River and shortnose sucker investigations in Clear Lake, California--2011 pilot study summary

    Science.gov (United States)

    Burdick, Summer M.; Rasmussen, Josh

    2012-01-01

    Poor recruitment appears to limit the recovery of Lost River and shortnose sucker populations in Clear Lake Reservoir, California, but the cause is unknown. Adult suckers migrate up Willow Creek and its tributaries to spawn in some years, but low flow in Willow Creek may inhibit spawning migrations in other years. It is unclear whether spawning is successful, larvae survive, or juveniles persist to adulthood. Environmental variables associated with successful spawning or young-of-year survival have not been identified and early life history for these populations is poorly understood. The U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service and Ruby Pipeline L.L.C. Corporation (El Paso, Tex.) initiated a study in 2011 to better understand juvenile sucker life history in Clear Lake Reservoir, and to identify constraints in the early life history that may limit recruitment to the adult spawning populations. This is a report on the 2011 pilot study for this project.

  4. Clear Lake sediments: anthropogenic changes in physical sedimentology and magnetic response.

    Science.gov (United States)

    Osleger, David A; Zierenberg, Robert A; Suchanek, Thomas H; Stoner, Joseph S; Morgan, Sally; Adam, David P

    2008-12-01

    We analyzed the sedimentological characteristics and magnetic properties of cores from the three basins of Clear Lake, California, USA, to assess the depositional response to a series of land use changes that occurred in the watershed over the 20th century. Results indicate that distinct and abrupt shifts in particle size, magnetic concentration/mineralogy, and redox conditions occur concurrently with a variety of ecological and chemical changes in lake bed sediments. This coincidence of events occurred around 1927, a datum determined by an abrupt increase in total mercury (Hg) in Clear Lake cores and the known initiation of open-pit Hg mining at the Sulphur Bank Mercury Mine, confirmed by 210Pb dating. Ages below the 1927 horizon were determined by accelerator mass spectrometry on 14C of coarse organic debris. Calculated sedimentation rates below the 1927 datum are approximately 1 mm/yr, whereas rates from 1927 to 2000 are up to an order of magnitude higher, with averages of approximately 3.5-19 mm/yr. In both the Oaks and Upper Arms, the post-1927 co-occurrence of abrupt shifts in magnetic signatures with color differences indicative of changing redox conditions is interpreted to reflect a more oxygenated diagenetic regime and rapid burial of sediment below the depth of sulfate diffusion. Post-1927 in the Oaks Arm, grain size exhibits a gradual coarsening-upward pattern that we attribute to the input of mechanically deposited waste rock related to open-pit mining activities at the mine. In contrast, grain size in the Upper Arm exhibits a gradational fining-upward after 1927 that we interpret as human-induced erosion of fine-grained soils and chemically weathered rocks of the Franciscan Assemblage by heavy earthmoving equipment associated with a road- and home-building boom, exacerbated by stream channel mining and wetlands destruction. The flux of fine-grained sediment into the Upper Arm increased the nutrient load to the lake, and that in turn catalyzed profuse

  5. Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  6. Lake Morphometry for NHD Lakes in California Region 18 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  7. Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  8. The Great Lakes' regional climate regimes

    Science.gov (United States)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  9. Narrative report: May through August, 1957: Tule Lake, Lower Klamath, Upper Klamath, Clear Lake National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from May through August of 1957. The report begins by summarizing the...

  10. Narrative report: January through April, 1957: Tule Lake, Lower Klamath, Upper Klamath, and Clear Lake National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1957. The report begins by summarizing the...

  11. Narrative report: Tule Lake, Lower Klamath, Upper Klamath, and Clear Lake National Wildlife Refuges: January, February, March, April, 1955

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1955. The report begins by summarizing the...

  12. Narrative report: May through August, 1958: Tule Lake, Lower Klamath, Upper Klamath, Clear Lake National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from May through August of 1958. The report begins by summarizing the...

  13. Narrative report: Tule Lake, Lower Klamath, Upper Klamath, and Clear Lake National Wildlife Refuges: September - December, 1955

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from September through December of 1955. The report begins by...

  14. Narrative report: Tule Lake, Lower Klamath, Upper Klamath, and Clear Lake National Wildlife Refuges: January through April, 1954

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1954. The report begins by summarizing...

  15. Narrative report: January through April, 1960: Tule Lake, Lower Klamath, Upper Klamath, Clear Lake, Klamath Marsh National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1960. The report begins by summarizing the...

  16. Potential Impacts of Climate Change in the Great Lakes Region

    Science.gov (United States)

    Winkler, J. A.

    2011-12-01

    Climate change is projected to have substantial impacts in the Great Lakes region of the United States. One intent of this presentation is to introduce the Great Lakes Integrated Sciences and Assessments Center (GLISA), a recently-funded NOAA RISA center. The goals and unique organizational structure of GLISA will be described along with core activities that support impact and assessment studies in the region. Additionally, observed trends in temperature, precipitation including lake effect snowfall, and lake temperatures and ice cover will be summarized for the Great Lakes region, and vulnerabilities to, and potential impacts of, climate change will be surveyed for critical natural and human systems. These include forest ecosystems, water resources, traditional and specialized agriculture, and tourism/recreation. Impacts and vulnerabilities unique to the Great Lakes region are emphasized.

  17. Limnological characteristics of 56 lakes in the Central Canadian Arctic Treeline Region

    Directory of Open Access Journals (Sweden)

    John P. SMOL

    2003-02-01

    Full Text Available Measured environmental variables from 56 lakes across the Central Canadian Treeline Region exhibited clear limnological differences among subpolar ecozones, reflecting strong latitudinal changes in biome characteristics (e.g. vegetation, permafrost, climate. Principal Components Analysis (PCA clearly separated forested sites from tundra sites based on distinct differences in limnological characteristics. Increases in major ions and related variables (e.g. dissolved inorganic carbon, DIC were higher in boreal forest sites in comparison to arctic tundra sites. The higher values recorded in the boreal forest lakes may be indirectly related to differences in climatic factors in these zones, such as the degree of permafrost development, higher precipitation and runoff, duration of ice-cover on the lakes, and thicker and better soil development. Similar to trends observed in DIC, substantially higher values for dissolved organic carbon (DOC were measured in boreal forest lakes than in arctic tundra lakes. This was likely due to higher amounts of catchment-derived DOC entering the lakes from coniferous leaf litter sources. Relative to arctic tundra lakes, boreal forest lakes had higher nutrient concentrations, particularly total nitrogen (TN, likely due to warmer conditions, a longer growing season, and higher precipitation, which would enhance nutrient cycling and primary productivity. Results suggest that modern aquatic environments at opposite sides of the central Canadian arctic treeline (i.e. boreal forest and arctic tundra exhibit distinct differences in water chemistry and physical conditions. These limnological trends may provide important information on possible future changes with additional warming.

  18. Food web efficiency differs between humic and clear water lake communities in response to nutrients and light.

    Science.gov (United States)

    Faithfull, C L; Mathisen, P; Wenzel, A; Bergström, A K; Vrede, T

    2015-03-01

    This study demonstrates that clear and humic freshwater pelagic communities respond differently to the same environmental stressors, i.e. nutrient and light availability. Thus, effects on humic communities cannot be generalized from existing knowledge about these environmental stressors on clear water communities. Small humic lakes are the most numerous type of lake in the boreal zone, but little is known about how these lakes will respond to increased inflows of nutrients and terrestrial dissolved organic C (t-DOC) due to climate change and increased human impacts. Therefore, we compared the effects of nutrient addition and light availability on pelagic humic and clear water lake communities in a mesocosm experiment. When nutrients were added, phytoplankton production (PPr) increased in both communities, but pelagic energy mobilization (PEM) and bacterial production (BP) only increased in the humic community. At low light conditions, the addition of nutrients led to increased PPr only in the humic community, suggesting that, in contrast to the clear water community, humic phytoplankton were already adapted to lower ambient light levels. Low light significantly reduced PPr and PEM in the clear water community, but without reducing total zooplankton production, which resulted in a doubling of food web efficiency (FWE = total zooplankton production/PEM). However, total zooplankton production was not correlated with PEM, PPr, BP, PPr:BP or C:nutrient stoichiometry for either community type. Therefore, other factors such as food chain length, food quality, ultra-violet radiation or duration of the experiment, must have determined total zooplankton production and ultimately FWE.

  19. Influence of hydrological pulse on bacterial growth and DOC uptake in a clear-water Amazonian lake.

    Science.gov (United States)

    Farjalla, Vinicius F; Azevedo, Debora A; Esteves, Francisco A; Bozelli, Reinaldo L; Roland, Fabio; Enrich-Prast, Alex

    2006-08-01

    This study was conducted to evaluate: (1) the bacterial growth and the dissolved organic carbon (DOC) uptake in an Amazonian lake (Lake Batata) at high-water and low-water periods of the flood pulse; (2) the influence of nitrogen and phosphorus (NP) additions on bacterial growth and DOC uptake in Lake Batata at two flood pulse periods; and (3) the bioavailability of the main DOC sources in Lake Batata. Lake Batata is a typical clear-water Amazonian lake, located in the watershed of Trombetas River, Central Amazon, Brazil. Bacterial batch cultures were set up with 90% 0.2-microm filtered water and 10% inoculum from Lake Batata. N-NH(4)NO(3) and P-KH(2)PO(4), with final concentrations of 50 and 5 microM, respectively, were added to the cultures, except for controls. Extra sources of DOC (e.g., algal lysate, plant leachates) were added to constitute six distinct treatments. Bacterial response was measured by maximum bacterial abundance and rates of bacterial production, respiration, DOC uptake, and bacterial growth efficiency (BGE). Bacterial growth and DOC uptake were higher in NP treatments than in controls, indicating a consistent nutrient limitation in Lake Batata. The composition of DOC also seems to be an important regulating factor of bacterial growth in Lake Batata. Seasonally, bacterial growth and DOC bioavailability were higher at low-water period, when the phytoplankton is a significant extra source of DOC, than at high-water period, when the forest is the main source of DOC. DOC bioavailability was better estimated based on the diversity and the diagenetic stage of carbon compounds than on single classes of labile compounds. Changes in BGE were better related to CNP stoichiometry in the water, and the "excess" of organic substrates was oxidized in catabolism, despite the quality of these compounds for bacterial growth. Finally, we conclude that bacterial growth and DOC uptake vary throughout the flood pulse in clear-water Amazonian ecosystems as a result

  20. Impact of lake-river connectivity and interflow on the Canadian RCM simulated regional climate and hydrology for Northeast Canada

    Science.gov (United States)

    Huziy, O.; Sushama, L.

    2017-02-01

    Lakes affect regional climate by modulating surface albedo, surface energy, and moisture budgets. This is especially important for regions such as Northeast Canada with approximately 10 % of the landmass covered by lakes, wetlands and rivers. From the regional hydrology perspective, interactions between lakes and rivers are important as streamflow patterns can be significantly modified by lake storage, and similarly lake levels can be modified by streamflows. In this study, using a suite of experiments performed with the fifth generation Canadian Regional Climate Model (CRCM5) driven by the European Centre for Medium range Weather Forecasting ERA40 reanalysis data at the lateral boundaries for the 1979-2010 period, lake-river-atmosphere interactions and their impact on the regional climate/hydrology of north-east Canada are assessed. In these CRCM5 simulations, a one-dimensional lake model represents lakes, while the rivers are modeled using a distributed routing scheme, and one of the simulations includes interflow, i.e. lateral flow of water in the soil layers. Comparison of CRCM5 simulations with and without lakes suggests significant differences in winter/summer precipitation and winter temperature for the study region. CRCM5 simulations performed with and without lake-river interactions suggest improved representation of streamflows when lake storage and routing are taken into account. Adding the interflow process leads to increased streamflows during summer and fall seasons for the majority of the rivers, causing modest changes to land-atmosphere interactions via modified soil moisture. The impact of interflow on streamflow, obtained in this study, is comparable to the impact of lake-atmosphere interactions on streamflows. This study clearly demonstrates the need for realistic representation of lake-river interactions in regional climate models for realistic simulation of regional hydrology, particularly streamflows.

  1. Advances in thermokarst lake research in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    FuJun Niu; GuoDong Cheng; Jing Luo; ZhanJu Lin

    2014-01-01

    A-thermokarst-lake-is-defined-as-a-lake-occupying-a-closed-depression-formed-by-ground-settlement-following-thawing-of-ice-rich-permafrost-or-the-melting-of-massive-ice.-As-it-is-the-most-visible-morphologic-landscape-developed-during-the-process-of-permafrost-degradation,-we-reviewed-recent-literature-on-thermokarst-studies,-and-summarized-the-main-study-topics-as:-development-and-temporal-evolution,-carbon-release,-and-ecological-and-engineering-influence-of-thermokarst-lakes.-The-climate-warming,-forest-fires,-surface-water-pooling,-geotectonic-fault-and-anthropogenic-ac-tivity-are-the-main-influencing-factors-that-cause-an-increase-of-ground-temperatures-and-melting-of-ice-rich-permafrost,-resulting-in-thermokarst-lake-formation.-Normally-a-thermokarst-lake-develops-in-3-5-stages-from-initiation-to-perma-frost-recovery.-Geo-rectified-aerial-photographs-and-remote-sensing-images-show-that-thermokarst-lakes-have-been-mainly-experiencing-the-process-of-shrinkage-or-disappearance-in-most-regions-of-the-Arctic,-while-both-lake-numbers-and-areas-on-the-Qinghai-Tibet-Plateau-have-increased.-Field-studies-and-modeling-indicates-that-carbon-release-from-thermokarst-lakes-can-feedback-significantly-to-global-warming,-thus-enhancing-our-understanding-of-the-influences-of-thermokarst-lakes-on-the-ecological-environment,-and-on-regional-groundwater-through-drainage.-Based-on-field-mon-itoring-and-numerical-simulations,-infrastructure-stability-can-be-affected-by-thermal-erosion-of-nearby-thermokarst-lakes.-This-review-was-undertaken-to-enhance-our-understanding-of-thermokarst-lakes,-and-providing-references-for-future-comprehensive-studies-on-thermokarst-lakes.

  2. Anthropogenic climate change in the Playa Lakes Joint Venture region

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Anthropogenic climate change has been driving regional climate shifts in the Playa Lakes Joint Venture zone since at least the mid 1970s. As a result, summers are...

  3. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  4. Utilization of a Marketing Strategy at Naval Regional Medical Center Great Lakes, Great Lakes, Illinois

    Science.gov (United States)

    1983-06-01

    UTILIZATION OF A MARKETING STRATEGY AToNAVAL REGIONAL MEDICAL CENTER GREAT LAKES NGREAT LAKES, ILLINOIS I DTIC S1 ELECTE I A Graduate Research...IWORK UNIT ELEMENT NO. NO. NO. rCCESSION NO. 11. TITLE (bw* u S.wufty asification) Utilization of A Marketing Strategy At Naval Regional Medical Center...Applied Research Question. ........ 37 Summary of the Steps of a Marketing Strategy .. ..... 38 Applicability to the Military Health Care System

  5. Forecasting Lake-Effect Precipitation in the Great Lakes Region Using NASA Enhanced-Satellite Data

    Science.gov (United States)

    Cipullo, Michelle; Molthan, Andrew; Shafer, Jackie; Case, Jonathan; Jedlovec, Gary

    2011-01-01

    Lake-effect precipitation is common in the Great Lakes region, particularly during the late fall and winter. The synoptic processes of lake-effect precipitation are well understood by operational forecasters, but individual forecast events still present a challenge. Locally run, high resolution models can assist the forecaster in identifying the onset and duration of precipitation, but model results are sensitive to initial conditions, particularly the assumed surface temperature of the Great Lakes. The NASA Short-term Prediction Research and Transition (SPoRT) Center has created a Great Lakes Surface Temperature (GLST) composite, which uses infrared estimates of water temperatures obtained from the MODIS instrument aboard the Aqua and Terra satellites, other coarser resolution infrared data when MODIS is not available, and ice cover maps produced by the NOAA Great Lakes Environmental Research Lab (GLERL). This product has been implemented into the Weather Research and Forecast (WRF) model Environmental Modeling System (WRF-EMS), used within forecast offices to run local, high resolution forecasts. The sensitivity of the model forecast to the GLST product was analyzed with a case study of the Lake Effect Storm Echinacea, which produced 10 to 12 inches of snowfall downwind of Lake Erie, and 8 to 18 inches downwind of Lake Ontario from 27-29 January 2010. This research compares a forecast using the default Great Lakes surface temperatures from the Real Time Global sea surface temperature (RTG SST), in the WRF-EMS model to the enhanced NASA SPoRT GLST product to study forecast impacts. Results from this case study show that the SPoRT GLST contained less ice cover over Lake Erie and generally cooler water temperatures over Lakes Erie and Ontario. Latent and sensible heat fluxes over Lake Ontario were decreased in the GLST product. The GLST product decreased the quantitative precipitation forecast (QPF), which can be correlated to the decrease in temperatures and heat

  6. Palaeolimnological assessment of lake acidification and environmental change in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Sergi PLA

    2010-08-01

    Full Text Available Exploitation of the Athabasca Oil Sands has expanded hugely over the last 40 years. Regional emissions of oxidised sulphur and nitrogen compounds increased rapidly over this period and similar emissions have been linked to lake acidification in other parts of North America and Europe. To determine whether lakes in the region have undergone acidification, 12 lakes within the Regional Municipality of Wood Buffalo and the Caribou Mountains were selected to cover chemical and spatial gradients and sediment cores were obtained for palaeolimnological analyses including radiometric dating, diatom analysis, isotopic analysis of bulk sediment 13C and 15N, and spheroidal carbonaceous particles (SCPs. All lake sediment cores show evidence of industrial contamination based on SCPs, but there is no clear industrial signal in stable isotopes. Most lakes showed changes in diatom assemblages and sediment C:N ratios consistent with nutrient enrichment over various timescales, with potential drivers including climatic change, forest fires and anthropogenic nitrogen deposition. Only one of the 12 lakes investigated showed strong evidence of acidification with a decline in diatom-inferred pH from 6.3 to 5.6 since 1970 linked to increasing relative abundances of the acidophilous diatom species Actinella punctata, Asterionella ralfsii and Fragilariforma polygonata. Analysis of mercury (Hg in the acidified lake showed increasing sediment fluxes over the last 20 years, a possible indication of industrial contamination. The acidified lake is the smallest of those studied with the shortest residence time, suggesting a limited capacity for neutralisation of acid inputs in catchment soils or by inlake processes.

  7. Lake breezes in the southern Great Lakes region and their influence during BAQS-Met 2007

    Directory of Open Access Journals (Sweden)

    D. M. L. Sills

    2011-02-01

    Full Text Available Mesoscale observations from the BAQS-Met field experiment during the summer of 2007 were integrated and manually analyzed in order to identify and characterize lake breezes in the southern Great Lakes region of North America, and assess their potential impact on air quality. Lake breezes were found to occur on 90% of study days, often occurring in conditions previously thought to impede their development. They affected all parts of the study region, including southwestern Ontario and nearby portions of southeast Michigan and northern Ohio, occasionally penetrating inland from 100 km to over 200 km. Occurrence rates and penetration distances were found to be higher than previously reported in the literature. This more accurate depiction of observed lake breezes allows a better understanding of their influence on the production and transport of pollutants in this region.

    The observational analyses were compared with output from subsequent runs of a high-resolution numerical weather prediction model. The model accurately predicted lake breeze occurrence in a variety of synoptic wind regimes, but selected cases showed substantial differences in the detailed timing and location of lake-breeze fronts, and with the initiation of deep moist convection. Knowledge of such strengths and weaknesses will assist with interpretation of results from air quality modelling driven by this meteorological model.

  8. Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

    OpenAIRE

    Chen, W.; T. Doko; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

    2014-01-01

    The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the gl...

  9. Reaching Regional and Local Learners via a Great Lakes MOOC

    Science.gov (United States)

    Mooney, M. E.; Ackerman, S. A.

    2015-12-01

    The Cooperative Institute of Meteorological Satellite Studies (CIMSS) took a regional approach to climate change education in a 4-week MOOC (Massive Open On-line Course) on the Changing Weather and Climate in the Great Lakes Region launched in February 2015. Featuring a different season each week, this Great Lakes MOOC includes lectures about seasonal weather conditions, observed changes, and societal impacts of regional climate change, as well as actions with co-benefits to slow future climate change. To better connect with learners, CIMSS facilitated 21 discussion groups at public libraries around Wisconsin each week. Participants discussed climate change impacts in their communities as well as strategies to mitigate climate change. Not surprisingly, initial survey results show library participants were more committed, engaged, climate literate, and community minded. This session will share lessons learned and survey results from the Great Lakes MOOC which remains open and accessible on Coursera through February 2016 at https://www.coursera.org/course/greatlakesclimate.

  10. Regional assessment of lake water clarity using satellite remote sensing

    Directory of Open Access Journals (Sweden)

    David L. SKOLE

    2003-09-01

    Full Text Available Lake water clarity as measured by Secchi disk transparency (SDT is a cost-effective measure of water quality. However, in regions where there are thousands of lakes, sampling even a small proportion of those lakes for SDT year after year is cost prohibitive. Remote sensing has the potential to be a powerful tool for assessing lake clarity over large spatial scales. The overall objective of our study was to examine whether Landsat-7 ETM+ could be used to measure water clarity across a large range of lakes. Our specific objectives were to: 1 develop a regression model to estimate SDT from Landsat data calibrated using 93 lakes in Michigan, U.S.A., and to 2 examine how the distribution of SDT across the 93 calibration lakes influenced the model. Our calibration dataset included a large number of lakes with a wide range of SDT values that captured the summer statewide distribution of SDT values in Michigan. Our regression model had a much lower r2 value than previously published studies conducted on smaller datasets. To examine the importance of the distribution of calibration data, we simulated a calibration dataset with a different SDT distribution by sub-sampling the original dataset to match the distribution of previous studies. The sub-sampled dataset had a much higher percentage of lakes with shallow water clarity, and the resulting regression model had a much higher r2 value than our original model. Our study shows that the use of Landsat to measure water clarity is sensitive to the distribution of water clarity used in the calibration set.

  11. Regionalization of precipitation characteristics in Iran's Lake Urmia basin

    Science.gov (United States)

    Fazel, Nasim; Berndtsson, Ronny; Uvo, Cintia Bertacchi; Madani, Kaveh; Kløve, Bjørn

    2017-03-01

    Lake Urmia in northwest Iran, once one of the largest hypersaline lakes in the world, has shrunk by almost 90% in area and 80% in volume during the last four decades. To improve the understanding of regional differences in water availability throughout the region and to refine the existing information on precipitation variability, this study investigated the spatial pattern of precipitation for the Lake Urmia basin. Daily rainfall time series from 122 precipitation stations with different record lengths were used to extract 15 statistical descriptors comprising 25th percentile, 75th percentile, and coefficient of variation for annual and seasonal total precipitation. Principal component analysis in association with cluster analysis identified three main homogeneous precipitation groups in the lake basin. The first sub-region (group 1) includes stations located in the center and southeast; the second sub-region (group 2) covers mostly northern and northeastern part of the basin, and the third sub-region (group 3) covers the western and southern edges of the basin. Results of principal component (PC) and clustering analyses showed that seasonal precipitation variation is the most important feature controlling the spatial pattern of precipitation in the lake basin. The 25th and 75th percentiles of winter and autumn are the most important variables controlling the spatial pattern of the first rotated principal component explaining about 32% of the total variance. Summer and spring precipitation variations are the most important variables in the second and third rotated principal components, respectively. Seasonal variation in precipitation amount and seasonality are explained by topography and influenced by the lake and westerly winds that are related to the strength of the North Atlantic Oscillation. Despite using incomplete time series with different lengths, the identified sub-regions are physically meaningful.

  12. Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Josef MacLeod

    2016-11-01

    Full Text Available Changes in the far north of Ontario (>50°N latitude, like climate warming and increased industrial development, will have direct effects on watershed characteristics and lakes. To better understand the nature of remote northern lakes that span the Canadian Shield and Hudson Bay Lowlands, and to address the pressing need for limnological data for this vast, little-studied area of Ontario, lake chemistry surveys were conducted during 2011-2012. Lakes at the transition between these physiographic regions displayed highly variable water chemistry, reflecting the peatland landscape with a mix of bog and fen watersheds, and variations in the extent of permafrost. In the transition area, Shield and Lowlands lakes could not be clearly differentiated based on water chemistry; peat cover decouples, to varying degrees, the lakes from the influences of bedrock and surficial deposits. Regional chemistry differences were apparent across a much broader area of northern Ontario, due to large-scale spatial changes in geology and in the extent of peatlands and permafrost.  Shield lakes in the far northwest of Ontario had Ca, Mg, and TP concentrations markedly higher than those of many Lowlands lakes and previously studied Shield lakes south of 50°N, related to an abundance of lacustrine and glacial end-moraine deposits in the north.

  13. Interactive lakes in the Canadian Regional Climate Model, version 5: the role of lakes in the regional climate of North America

    Directory of Open Access Journals (Sweden)

    Bernard Dugas

    2012-02-01

    Full Text Available Two one-dimensional (1-D column lake models have been coupled interactively with a developmental version of the Canadian Regional Climate Model. Multidecadal reanalyses-driven simulations with and without lakes revealed the systematic biases of the model and the impact of lakes on the simulated North American climate.The presence of lakes strongly influences the climate of the lake-rich region of the Canadian Shield. Due to their large thermal inertia, lakes act to dampen the diurnal and seasonal cycle of low-level air temperature. In late autumn and winter, ice-free lakes induce large sensible and latent heat fluxes, resulting in a strong enhancement of precipitation downstream of the Laurentian Great Lakes, which is referred to as the snow belt.The FLake (FL and Hostetler (HL lake models perform adequately for small subgrid-scale lakes and for large resolved lakes with shallow depth, located in temperate or warm climatic regions. Both lake models exhibit specific strengths and weaknesses. For example, HL simulates too rapid spring warming and too warm surface temperature, especially in large and deep lakes; FL tends to damp the diurnal cycle of surface temperature. An adaptation of 1-D lake models might be required for an adequate simulation of large and deep lakes.

  14. [Ecological compensation standard in Dongting Lake region of returning cropland to lake based on emergy analysis].

    Science.gov (United States)

    Mao, De-Hua; Hu, Guang-Wei; Liu, Hui-Jie; Li, Zheng-Zui; Li, Zhi-Long; Tan, Zi-Fang

    2014-02-01

    The annual emergy and currency value of the main ecological service value of returning cropland to lake in Dongting Lake region from 1999 to 2010 was calculated based on emergy analysis. The calculation method of ecological compensation standard was established by calculating annual total emergy of ecological service function increment since the starting year of returning cropland to lake, and the annual ecological compensation standard and compensation area were analyzed from 1999 to 2010. The results indicated that ecological compensation standard from 1999 to 2010 was 40.31-86.48 yuan x m(-2) with the mean of 57.33 yuan x m(-2). The ecological compensation standard presented an increase trend year by year due to the effect of eco-recovery of returning cropland to lake. The ecological compensation standard in the research area presented a swift and steady growth trend after 2005 mainly due to the intensive economy development of Hunan Province, suggesting the value of natural ecological resources would increase along with the development of society and economy. Appling the emergy analysis to research the ecological compensation standard could reveal the dynamics of annual ecological compensation standard, solve the abutment problem of matter flow, energy flow and economic flow, and overcome the subjective and arbitrary of environment economic methods. The empirical research of ecological compensation standard in Dongting Lake region showed that the emergy analysis was feasible and advanced.

  15. Regional variability among nonlinear chlorophyll-phosphorus relationships in lakes

    Science.gov (United States)

    Filstrup, Christopher T.; Wagner, Tyler; Soranno, Patricia A.; Stanley, Emily H.; Stow, Craig A.; Webster, Katherine E.; Downing, John A.

    2014-01-01

    The relationship between chlorophyll a (Chl a) and total phosphorus (TP) is a fundamental relationship in lakes that reflects multiple aspects of ecosystem function and is also used in the regulation and management of inland waters. The exact form of this relationship has substantial implications on its meaning and its use. We assembled a spatially extensive data set to examine whether nonlinear models are a better fit for Chl a—TP relationships than traditional log-linear models, whether there were regional differences in the form of the relationships, and, if so, which regional factors were related to these differences. We analyzed a data set from 2105 temperate lakes across 35 ecoregions by fitting and comparing two different nonlinear models and one log-linear model. The two nonlinear models fit the data better than the log-linear model. In addition, the parameters for the best-fitting model varied among regions: the maximum and lower Chl aasymptotes were positively and negatively related to percent regional pasture land use, respectively, and the rate at which chlorophyll increased with TP was negatively related to percent regional wetland cover. Lakes in regions with more pasture fields had higher maximum chlorophyll concentrations at high TP concentrations but lower minimum chlorophyll concentrations at low TP concentrations. Lakes in regions with less wetland cover showed a steeper Chl a—TP relationship than wetland-rich regions. Interpretation of Chl a—TP relationships depends on regional differences, and theory and management based on a monolithic relationship may be inaccurate.

  16. Wind energy resource atlas. Volume 3. Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Paton, D.L.; Bass, A.; Smith, D.G.; Elliott, D.L.; Barchet, W.R.; George, R.L.

    1981-02-01

    The Great Lakes Region atlas assimilates six collections of wind resource data, one for the region and one for each of the five states that compose the Great Lakes region: Illinois, Indiana, Michigan, Ohio, Wisconsin. At the state level, features of the climate, topography, and wind resource are discussed in greater detail than in the regional discussion and the data locations on which the assessment is based are mapped. Variations over several time scales in the wind resource at selected stations in each state are shown on graphs of monthly average and interannual wind speed and power, and of hourly average wind speed for each season. Other graphs present speed, direction, and duration frequencies of the wind at these locations.

  17. Chemistry of snow and lake water in Antarctic region

    Indian Academy of Sciences (India)

    Kaushar Ali; Sunil Sonbawane; D M Chate; Devendraa Siingh; P S P Rao; P D Safai; K B Budhavant

    2010-12-01

    Surface snow and lake water samples were collected at different locations around Indian station at Antarctica, Maitri, during December 2004-March 2005 and December 2006-March 2007.Samples were analyzed for major chemical ions. It is found that average pH value of snow is 6.1. Average pH value of lake water with low chemical content is 6.2 and of lake water with high chemical content is 6.5.The Na+ and Cl− are the most abundantly occurring ions at Antarctica. Considerable amount of SO$^{2-}_{4}$ is also found in the surface snow and the lake water which is attributed to the oxidation of DMS produced by marine phytoplankton.Neutralization of acidic components of snow is mainly done by NH$^{+}_{4}$ and Mg2+. The Mg2+, Ca2+ and K+ are nearly equally effective in neutralizing the acidic components in lake water.The NH$^{+}_{4}$ and SO$^{2-}_{4}$ occur over the Antarctica region mostly in the form of (NH4)2SO4.

  18. Resettlement's impact on the domestic economy in lake restoration:case study of Poyang Lake region

    Institute of Scientific and Technical Information of China (English)

    YAN Yu-ping; YAN Bang-you; LI Weng-hua

    2010-01-01

    The Chinese government started a lake restoration project in Poyang Lake region 10 years ago,and the expost monitor of the migrants' livelihoods was limited.This paper compares the composition difference of domestic income and domestic consumption between migration and non-migration villages in Poyang Lake region.The results show that the migrants' domestic income has increased in the last 10 years,which originated from the increasing trend of active and extensive rural labor migration,while the resettlement has not influenced the domestic income significantly.The resettlement stimulates younger farmers to work far away from home whose wages contribute nearly 80% of domestic income.The resettlement decreases their savings due to higher expenditure of daily life for those who work far away from home,and higher expenditure of food for those who stay at home,losing cultivated lands with irrigation system for vegetable.On the other hand,the increase of rural labor migration leads the migrants who stay at home to have access to more cultivated lands for rice and cotton,and the farmers also apply more fertilizer in the same cultivated land for more agriculture products.The resettlement makes most of migrants spend their savings on the improvement of their housing conditions due to not enough governmental financial support for new building.After the analysis,some factors that influence migrants' income and consumption are discussed.The paper may contribute to the building of Poyang Lake Ecological Economic Zone.

  19. Great Lakes Offshore Wind Project: Utility and Regional Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Loparo, Kenneth A.; Sajadi, Amir; D' Aquila, Robert; Clark, Kara; Waligorski, Joseph; Baker, Scott

    2016-06-30

    This project aims to identify transmission system upgrades needed to facilitate offshore wind projects as well as operational impacts of offshore generation on operation of the regional transmission system in the Great Lakes region. A simulation model of the US Eastern Interconnection was used as the test system as a case study for investigating the impact of the integration of a 1000MW offshore wind farm operating in Lake Erie into FirstEnergy/PJM service territory. The findings of this research provide recommendations on offshore wind integration scenarios, the locations of points of interconnection, wind profile modeling and simulation, and computational methods to quantify performance, along with operating changes and equipment upgrades needed to mitigate system performance issues introduced by an offshore wind project.

  20. Climate Change Assessments for Lakes Region of Turkey

    Directory of Open Access Journals (Sweden)

    Ayten Erol

    2012-07-01

    Full Text Available Climate change is one of the most important challenges for forestry. Forests are known to be most efficient natural tools to ensure availability and quality of water in many regions. Besides, planning of forest resources towards water quality and quantity is essential in countries that are expected to face with more frequent drought periods in the next decades due to climate change. Watershed management concept has been supposed as the primary tool to plan natural resources in a more efficient and sustainable way by both academicians and practitioners to mitigate and adapt climate change. Forest cover among other land use types provides the best regulating mechanism to mitigate erosion, sedimentation, desertification, and pollution. In addition, climate change can potentially affect forest stand dynamics by influencing the availability of water resources. Therefore, the amount of forest cover in a watershed is an indicator of climate change mitigation and adaptation. Climate change is a concern and risk for the sustainability of water resources in Lakes Region of Turkey. The objective of this study is to make a comprehensive assessment in lake watersheds of the Lakes region considering the forest cover. For this purpose, the study gives a general view of trends in climatic parameters using Mann Kendall trend test. The results showed that Mann Kendall trend test for temperature and precipitation data is not enough to evaluate the magnitude of potential changes of climate in terms of forest cover. Understanding impacts of changes in temperature and precipitation on forest cover, runoff data should be evaluated with temperature and precipitation for watersheds of forest areas in Lakes Region.

  1. Nitrogen deposition to lakes in national parks of the western Great Lakes region: Isotopic signatures, watershed retention, and algal shifts

    Science.gov (United States)

    Hobbs, William O.; Lafrancois, Brenda Moraska; Stottlemyer, Robert; Toczydlowski, David; Engstrom, Daniel R.; Edlund, Mark B.; Almendinger, James E.; Strock, Kristin E.; VanderMeulen, David; Elias, Joan E.; Saros, Jasmine E.

    2016-03-01

    Atmospheric deposition is a primary source of reactive nitrogen (Nr) to undisturbed watersheds of the Great Lakes region of the U.S., raising concerns over whether enhanced delivery over recent decades has affected lake ecosystems. The National Atmospheric Deposition Program (NADP) has been measuring Nr deposition in this region for over 35 years. Here we explore the relationships among NADP-measured Nr deposition, nitrogen stable isotopes (δ15N) in lake sediments, and the response of algal communities in 28 lakes situated in national parks of the western Great Lakes region of the U.S. We find that 36% of the lakes preserve a sediment δ15N record that is statistically correlated with some form of Nr deposition (total dissolved inorganic N, nitrate, or ammonium). Furthermore, measured long-term (since 1982) nitrogen biogeochemistry and inferred critical nitrogen loads suggest that watershed nitrogen retention and climate strongly affect whether sediment δ15N is related to Nr deposition in lake sediment records. Measurements of algal change over the last ~ 150 years suggest that Nr deposition, in-lake nutrient cycling, and watershed inputs are important factors affecting diatom community composition, in addition to direct climatic effects on lake physical limnology. The findings suggest that bulk sediment δ15N does reflect Nr deposition in some instances. In addition, this study highlights the interactive effects of Nr deposition and climate variability.

  2. PRODUCCIÓN PRIMARIA EN UN LAGO DE AGUAS CLARAS DE LA AMAZONÍA COLOMBIANA (LAGO BOA Primary Production In A Clear Water Lake Of Colombian Amazon (Lake Boa

    Directory of Open Access Journals (Sweden)

    GABRIEL ANTONIO PINILLA AGUDELO

    Full Text Available Dentro de los aspectos funcionales de un sistema acuático uno de los más determinantes es la producción fitoplanctónica. En este trabajo se midió la producción primaria del fitoplancton (método del 14C en un lago de aguas claras de la Amazonía colombiana, en diferentes momentos del ciclo hidrológico. La producción primaria osciló entre 0,6 y 2,3 g C m-2 d-1, valor este último medido durante la fase de aguas bajas. Estos resultados indican que la comunidad fitoplanctónica del lago Boa fluctúa desde condiciones de muy baja capacidad de asimilación de carbono inorgánico (aguas altas, hasta momentos en que este potencial se incrementa hasta cuatro veces (aguas bajas. Tales cambios drásticos obedecen a las fluctuaciones en la abundancia de microalgas, las que a su vez se presentan como respuesta a la variación trófica que tiene el lago durante el ciclo hidrológico. De esta manera, se pasa de condiciones oligotróficas en la época de inundación a un estado eutrófico cuando el sistema se desconecta del río en aguas bajas.Phytoplankton production is one of the most significant aspects in aquatic ecosystems. In this paper primary production of the phytoplankton community was measured (14C method in a clear water lake in the Colombian Amazon region in different periods of the hydrological cycle. Primary production varied between 0.6 and 2.3 g C m-2 d-1, the last recorded at low water phase. Results show that the phytoplankton community of Lake Boa fluctuates from very low capacity of carbon assimilation during high water but increased four times during low water. The strong change in productivity follows the variation in algal abundance, which in turn reflects changes in water quality conditions during the hydrologic cycle. Thus, the lake passes from oligotrophic conditions during the flooding period to eutrophic conditions when the lake is disconnected from the river at low water phase.

  3. Great Lakes Biomass State and Regional Partnership (GLBSRP)

    Energy Technology Data Exchange (ETDEWEB)

    Kuzel, Frederic

    2009-09-01

    The Council of Great Lakes Governors administered the Great Lakes Biomass State and Regional Partnership (GLBSRP) under contract with the U. S. Department of Energy (DOE). This Partnership grew out of the existing Regional Biomass Energy Program which the Council had administered since 1983. The GLBSRP includes the States of Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio and Wisconsin. The GLBSRP's overall goal is to facilitate the increased production and use of bioenergy and biobased products throughout the region. The GLBSRP has traditionally addressed its goals and objectives through a three-pronged approach: providing grants to the States; undertaking region-wide education, outreach and technology transfer projects; and, providing in-house management, support and information dissemination. At the direction of US Department of Energy, the primary emphasis of the GLBSRP in recent years has been education and outreach. Therefore, most activities have centered on developing educational materials, hosting workshops and conferences, and providing technical assistance. This report summarizes a selection of activities that were accomplished under this cooperative agreement.

  4. Narrative report: Klamath Basin National Wildlife Refuges: Tule Lake*, Lower Klamath*, and Clear Lake* in California, Upper Klamath* and Klamath Forest* in Oregon: 1969

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments during the 1969 calendar year. The report begins by summarizing the...

  5. Narrative report: Klamath Basin National Wildlife Refuges: Tule Lake, Lower Klamath, and Clear Lake in California, Upper Klamath and Klamath Forest in Oregon: January - April, 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1962. The report begins by summarizing the...

  6. Narrative report: January - April, 1961: Tule Lake, Lower Klamath, Clear Lake, Upper Klamath, and Klamath Forest National Wildlife Refuges, California and Oregon

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1961. The report begins by summarizing the...

  7. Narrative report: Klamath Basin National Wildlife Refuges: Tule Lake, Lower Klamath, and Clear Lake in California, Upper Klamath and Klamath Forest in Oregon: January - April, 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments from January through April of 1963. The report begins by summarizing the...

  8. Narrative report: Klamath Basin National Wildlife Refuges: Tule Lake, Lower Klamath, and Clear Lake in California, Upper Klamath and Klamath Forest in Oregon: 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Tule Lake National Wildlife Refuge outlines Refuge accomplishments during the 1965 calendar year. The report begins by summarizing the...

  9. 40 CFR 81.67 - Lake Michigan Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Regions § 81.67 Lake Michigan Intrastate Air Quality Control Region. The Menominee-Escanaba (Michigan)-Marinette (Wisconsin) Interstate Air Quality Control Region has been renamed the Lake Michigan Intrastate Air Quality Control Region (Wisconsin) and revised to consist of the territorial...

  10. Air pollution and environmental justice in the Great Lakes region

    Science.gov (United States)

    Comer, Bryan

    While it is true that air quality has steadily improved in the Great Lakes region, air pollution remains at unhealthy concentrations in many areas. Research suggests that vulnerable and susceptible groups in society -- e.g., minorities, the poor, children, and poorly educated -- are often disproportionately impacted by exposure to environmental hazards, including air pollution. This dissertation explores the relationship between exposure to ambient air pollution (interpolated concentrations of fine particulate matter, PM2.5) and sociodemographic factors (race, housing value, housing status, education, age, and population density) at the Census block-group level in the Great Lakes region of the United States. A relatively novel approach to quantitative environmental justice analysis, geographically weighted regression (GWR), is compared with a simplified approach: ordinary least squares (OLS) regression. While OLS creates one global model to describe the relationship between air pollution exposure and sociodemographic factors, GWR creates many local models (one at each Census block group) that account for local variations in this relationship by allowing the value of regression coefficients to vary over space, overcoming OLS's assumption of homogeneity and spatial independence. Results suggest that GWR can elucidate patterns of potential environmental injustices that OLS models may miss. In fact, GWR results show that the relationship between exposure to ambient air pollution and sociodemographic characteristics is non-stationary and can vary geographically and temporally throughout the Great Lakes region. This suggests that regulators may need to address environmental justice issues at the neighborhood level, while understanding that the severity of environmental injustices can change throughout the year.

  11. Characterization of Vibrio cholerae bacteriophages isolated from the environmental waters of the Lake Victoria region of Kenya.

    Science.gov (United States)

    Maina, Alice Nyambura; Mwaura, Francis B; Oyugi, Julius; Goulding, David; Toribio, Ana L; Kariuki, Samuel

    2014-01-01

    Over the last decade, cholera outbreaks have become common in some parts of Kenya. The most recent cholera outbreak occurred in Coastal and Lake Victoria region during January 2009 and May 2010, where a total of 11,769 cases and 274 deaths were reported by the Ministry of Public Health and Sanitation. The objective of this study is to isolate Vibrio cholerae bacteriophages from the environmental waters of the Lake Victoria region of Kenya with potential for use as a biocontrol for cholera outbreaks. Water samples from wells, ponds, sewage effluent, boreholes, rivers, and lakes of the Lake Victoria region of Kenya were enriched for 48 h at 37 °C in broth containing a an environmental strain of V. cholerae. Bacteriophages were isolated from 5 out of the 42 environmental water samples taken. Isolated phages produced tiny, round, and clear plaques suggesting that these phages were lytic to V. cholerae. Transmission electron microscope examination revealed that all the nine phages belonged to the family Myoviridae, with typical icosahedral heads, long contractile tails, and fibers. Head had an average diameter of 88.3 nm and tail of length and width 84.9 and 16.1 nm, respectively. Vibriophages isolated from the Lake Victoria region of Kenya have been characterized and the isolated phages may have a potential to be used as antibacterial agents to control pathogenic V. cholerae bacteria in water reservoirs.

  12. US-Canada Great Lakes Regional Specimen Bank Feasibility Study.

    Science.gov (United States)

    Kerry, A; Edmonds, C J; Landon, L; Yonker, T L

    1993-11-01

    A study to examine the feasibility of establishing a Regional Specimen Bank in the Great Lakes area of the United States and Canada has recently been initiated by the Michigan Audubon Society. There are several existing formal and informal specimen banking facilities active in the region but their combined adequacy has not been evaluated. This feasibility study will establish the need and use of a regional bank and the institution(s) necessary to satisfy this need will be recommended. The study will address the scope required to meet present and future needs including the types of specimens to be represented in the bank, geographic coverage and protocols for collection, shipping, processing, analysis and storage. A management policy of the bank will be developed encompassing business operation, costs, governing structure and personnel requirements. The legal requirements of the bank will be determined with regards to the acquisition of samples, transport across national boundaries, access to specimens and information, and liability during operation. An effective information dissemination network will be recommended that is compatible with national and international partners, will facilitate technology and information transfer and support the quality and status of the bank. Determination of secure, long-term funding sources will be one of the key elements to ensuring a safe repository. This feasibility study is funded by the Great Lakes Protection Fund.

  13. Quantitative Development and Distribution of Zooplankton in Medium Lakes of the Kostanay Region (North Kazakhstan Region)

    Science.gov (United States)

    Aubakirova, Gulzhan A.; Syzdykov, Kuanysh N.; Kurzhykayev, Zhumagazy; Uskenov, Rashit B.; Narbayev, Serik; Begenova, Ainagul B.; Zhumakayeva, Aikumys N.; Sabdinova, Dinara K.; Akhmedinov, Serikbay N.

    2016-01-01

    The assessment of water resources plays an important environmental and economic role, since it allows developing an effective program of regional development with regard to the environmental load. The hydro-chemical regime of lakes includes water temperature, content of biogenic elements, total mineralization, oxygen regime, and other parameters…

  14. Heavy metals in bottom sediments of Lake Umbozero in Murmansk Region, Russia

    DEFF Research Database (Denmark)

    Jernström, Jussi; Lehto, J.; Dauvalter, A.;

    2010-01-01

    Sediment cores collected from different locations of Lake Umbozero were studied with respect to concentration and mobility of trace and heavy metals Co, Cu, Fe, Mn, Ni, Pb, U, and Zn. Lake Umbozero is the second largest lake in the Murmansk Region and subjected to contamination by air-borne emiss...

  15. Isotopic structure of Lake Whitefish in Lake Huron: Evidence for regional and local populations based on resource use

    Science.gov (United States)

    Eberts, Rebecca L.; Wissel, Bjorn; Simpson, Gavin L.; Crawford, Stephen S.; Stott, Wendylee; Hanner, Robert H.; Manzon, Richard G.; Wilson, Joanna Y.; Boreham, Douglas R.; Somers, Christopher M.

    2017-01-01

    Lake Whitefish Coregonus clupeaformis is the most commercially valuable species in Lake Huron. The fishery for this species has historically been managed based on 25 management units (17 in Canada, 8 in the USA). However, congruence between the contemporary population structure of Lake Whitefish and management units is poorly understood. We used stable isotopes of carbon (δ13C) and nitrogen (δ15N), food web markers that reflect patterns in resource use (i.e., prey, location, habitat), to assess the population structure of spawning-phase Lake Whitefish collected from 32 sites (1,474 fish) across Lake Huron. We found large isotopic variation among fish from different sites (ranges: δ13C = 10.2‰, δ15N = 5.5‰) and variable niche size and levels of overlap (standard ellipse area = 1.0–4.3‰2). Lake Huron contained spawning-phase fish from four major isotopic clusters largely defined by extensive variation in δ13C, and the isotopic composition of fish sampled was spatially structured both within and between lake basins. Based on cluster compositions, we identified six putative regional groups, some of which represented sites of high diversity (three to four clusters) and others with less (one to two clusters). Analysis of isotopic values from Lake Whitefish collected from summer feeding locations and baseline prey items showed similar isotopic variation and established spatial linkage between spawning-phase and summer fish. Our results show that summer feeding location contributes strongly to the isotopic structure we observed in spawning-phase fish. One of the regional groups we identified in northern Georgian Bay is highly distinct based on isotopic composition and possibly ecologically unique within Lake Huron. Our findings are congruent with several previous studies using different markers (genetics, mark–recapture), and we conclude that current management units are generally too small and numerous to reflect the population structure of Lake Whitefish

  16. Do mining lakes in the Lusatian lignite mining region (Eastern Germany) affect regional precipitation patterns?

    Science.gov (United States)

    Brück, Yasemine; Pohle, Ina; Keuler, Klaus; Schaller, Eberhard; Hinz, Christoph

    2016-04-01

    Due to the flooding of former open-pit mines, Europe's largest artificial lake district is created in Eastern Germany. Between 1990 and 2006 more than 80 km² of new lakes have already been formed. These large-scale land cover changes may impact regional meteorological characteristics, therefore it is of interest, whether effects of the mining lakes can already be observed. We especially focus on whether the evaporation from the mining pit lakes leads to a higher precipitation on their lee side. To detect changes in the precipitation patterns, we analysed daily precipitation data (1980-2014) of 25 stations in an area of 10 000 km² widely around the lake district. Under the assumption that the influences of the lakes should be detectable either directly as trends in the observed data or as a deviation from a general measure for precipitation we combined statistical tests and principal component analysis (PCA). We applied pre-whitening Mann-Kendall tests to detect precipitation trends and Mann-Whitney tests to detect differences between split samples (before and after the flooding of most of the lakes). The PCA was applied based on the correlation matrix of daily precipitation at the different stations. As the daily precipitation can sufficiently be explained by the first five principal components, the recombination of these five principal components was used as a general measure of precipitation in the region. By regression trees (random forests) a relationship between the eigenvectors of the first five principal components and physiogeographic characteristics of the stations (e.g. altitude) was shown. Both the observed data and the deviations between the measurements and the recombination of the first five principal components showed divergent trends with high spatial variability and also interannual variability, but a pattern consistent with the lee side of the lake could not be detected. Therefore, it has been demonstrated that the emerging lakes had no

  17. Temporal-spatial variations of euphotic depth of typical lake regions in Lake Taihu and its ecological environmental significance

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Yunlin; QIN; Boqiang; HU; Weiping; WANG; Sumin; CHEN; Yuwei

    2006-01-01

    By using the data of underwater irradiance measured in the different lake regions of Lake Taihu during 1998-2004 and total suspended solids (TSS), wind speeds of the total 13 stations in typical lake regions during 1993-2003, this paper analyzes the factors of influencing on PAR (photosynthetically available radiation) attenuation, euphotic depth, and presents the temporal and spatial variations of euphotic depth of typical lake regions in Lake Taihu, and the spectral distributions of euphotic depth at station 2. The results show that the concentration of TSS is the most important factor impacting PAR attenuation, followed by chlorophyll a; chromophoric dissolved organic matter (CDOM) has little impact on the PAR euphotic depth. During 1993-2003, the mean yearly PAR euphotic depths of the typical lake regions ranged from 1.04 to 1.95 m with a mean value of 1.35±0.23 m. The PAR euphotic depth fell into 3 spatial zone types: Type I, the lowest, including the lake center and the inflows of rivers; Type II, intermediate, including Meiliang Bay, Wulihu Lake and Gonghu Bay; Type III, the greatest, including the East Lake Taihu; corresponding mean depths were approximately 1.1, 1.4, 2.0 m, respectively. The seasonal variations of euphotic depths were not quite the same in different lake regions. In the lake center, the mean values of PAR euphotic depth in summer and autumn were significantly greater than those in winter and spring; in the Meiliang Bay, winter means were significantly greater than in the other three seasons; in the East Lake Taihu, winter means were significantly less than in the other three seasons. However, no distinct seasonal change was recorded in the Wulihu Lake, Gonghu Bay and the inflows of rivers. The spectral distributions of euphotic depth present a minimal value at the blue light wave band of 400 nm, and a peak at the green light wave band of around 580 nm. In 1998 and 1999, based on the seasonal many-day continuous measurements, the PAR

  18. Clear Cell Sarcoma of Gluteal Region Malignant Melanoma of Soft Parts

    Directory of Open Access Journals (Sweden)

    Haren V. Oza

    2013-04-01

    Full Text Available Clear cell sarcoma (CCS is described as variant of sarcoma characterized by prominent clear cells showing features similar to malignant melanoma of soft parts. This neoplasm was first described by Dr. Franz m. Enzinger. Primary CCS usually arises in deeper soft tissues, in association with fascia, tendons, or aponeuroses. Clear cell sarcoma (CCS is a rare malignant tumor with a propensity for slow progressive invasion. It is a tumor derived from Melanoblast like cell. They occur most commonly in the extremities, with a predilection for young females. Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts and conventional malignant melanoma may demonstrate significant morphologic overlap at the light microscopic and ultra structural level. The tumor is very rare and can pose clinical challenges in early diagnosis. This case report demonstrates an unusual site of occurrence for clear cell sarcoma. [Natl J Med Res 2013; 3(2.000: 193-195

  19. Lake Morphometry for NHD Lakes in Pacific Northwest Region 17 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  20. Lake Morphometry for NHD Lakes in Lower Mississippi Region 8 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  1. Lake Morphometry for NHD Lakes in Upper Colorado Region 14 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  2. Lake Morphometry for NHD Lakes in Upper Mississippi Region 7 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  3. Lake Morphometry for NHD Lakes in Rio Grande Region 13 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  4. Lake Morphometry for NHD Lakes in Souris Red Rainy Region 9 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  5. Lake Morphometry for NHD Lakes in Lower Colorado Region 15 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  6. Lake Morphometry for NHD Lakes in Great Basin Region 16 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  7. Lake Morphometry for NHD Lakes in North East Region 1 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  8. Lake Morphometry for NHD Lakes in the Upper Portion of the Missouri Region 10 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  9. Birth Outcomes across Three Rural-Urban Typologies in the Finger Lakes Region of New York

    Science.gov (United States)

    Strutz, Kelly L.; Dozier, Ann M.; van Wijngaarden, Edwin; Glantz, J. Christopher

    2012-01-01

    Purpose: The study is a descriptive, population-based analysis of birth outcomes in the New York State Finger Lakes region designed to determine whether perinatal outcomes differed across 3 rural typologies. Methods: Hospital birth data for the Finger Lakes region from 2006 to 2007 were used to identify births classified as low birthweight (LBW),…

  10. Predicting Clear-Sky Reflectance Over Snow/Ice in Polar Regions

    Science.gov (United States)

    Chen, Yan; Sun-Mack, Sunny; Arduini, Robert F.; Hong, Gang; Minnis, Patrick

    2015-01-01

    Satellite remote sensing of clouds requires an accurate estimate of the clear-sky radiances for a given scene to detect clouds and aerosols and to retrieve their microphysical properties. Knowing the spatial and angular variability of clear-sky albedo is essential for predicting clear-sky radiance at solar wavelengths. The Clouds and the Earth's Radiant Energy System (CERES) Project uses the nearinfrared (NIR; 1.24, 1.6 or 2.13 micrometers), visible (VIS; 0.63 micrometers) and vegetation (VEG; 0.86 micrometers) channels available on the Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) to help identify clouds and retrieve their properties in both snow-free and snow-covered conditions. Thus, it is critical to have reliable distributions of clear-sky albedo for all of these channels. In CERES Edition 4 (Ed4), the 1.24-micrometer channel is used to retrieve cloud optical depth over snow/ice-covered surfaces. Thus, it is especially critical to accurately predict the 1.24-micrometer clear-sky albedo alpha and reflectance rho for a given location and time. Snow albedo and reflectance patterns are very complex due to surface texture, particle shapes and sizes, melt water, and vegetation protrusions from the snow surface. To minimize those effects, this study focuses on the permanent snow cover of Antarctica where vegetation is absent and melt water is minimal. Clear-sky albedos are determined as a function of solar zenith angle (SZA) from observations over all scenes determined to be cloud-free to produce a normalized directional albedo model (DRM). The DRM is used to develop alpha(SZA=0 degrees) on 10 foot grid for each season. These values provide the basis for predicting r at any location and set of viewing & illumination conditions. This paper examines the accuracy of this approach for two theoretical snow surface reflectance models.

  11. Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication--A Case Study in the Taihu Lake Basin (China).

    Science.gov (United States)

    Lin, Chen; Ma, Ronghua; He, Bin

    2015-12-24

    Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

  12. Evaluation of Regional Climate Simulations over the Great Lakes Region Driven by Three Global Data Sets

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Shiyuan (Sharon); Li, Xiuping; Bian, Xindi; Heilman, Warren E.; Leung, Lai-Yung R.; Gustafson, William I.

    2012-06-27

    The performance of regional climate simulations is evaluated for the Great Lakes region. Three 10-year (1990–1999) current-climate simulations are performed using the MM5 regional climate model (RCM) with 36-km horizontal resolution. The simulations employed identical configuration and physical parameterizations, but different lateral boundary conditions and sea-surface temperatures derived from the NCEP Global Reanalysis and output from the CCSM3 and GISS general circulation models (GCMs). The simulation results are compared to the North American Regional Reanalysis (NARR). The three RCM simulations appeared to be more accurate in winter and least accurate in summer, and more accurate aloft than near the surface. The reanalysis-constrained simulation adequately captured the spatial distribution and seasonal cycle of the observed surface-air temperature and precipitation, but it produced consistently across all seasons a cold bias that is generally larger over the lakes than over land and a wet bias due to an overestimation of nonconvective precipitation. The simulated seasonal cycle of moisture–flux convergence over the region was in very good agreement with NARR. The two GCM-driven runs adequately simulated the spatial and seasonal variation of temperature, but overestimated cold-season precipitation and underestimated summer precipitation, reversing the observed annual precipitation cycle. The GISS-driven run failed to simulate the prevailing low-level flow and moisture convergence patterns. All three RCM simulations successfully captured the impact of the Great Lakes on the region's climate, especially on winter precipitation, a significant improvement over coarse-resolution GCM simulations over the region.

  13. Seasonality of Water Chemistry, Carbonate Production, and Biometric Features of Two Species of Chara in a Shallow Clear Water Lake

    Directory of Open Access Journals (Sweden)

    Andrzej Pukacz

    2014-01-01

    Full Text Available The objective of this study was to analyze the temporal variability of biometric features and the carbonate production of two charophytes: Chara polyacantha A. Braun and Chara rudis A. Braun against the background of the physical-chemical properties of water. The investigation was carried out in a small, mid-forest Lake Jasne (western Poland. It is a polymictic, mesotrophic, hardwater ecosystem dominated by charophyte vegetation. Each month, 10 individuals of each species were characterized in terms of morphometric features, fresh and dry weight, and the percentage of calcium carbonate. Additionally, physical-chemical parameters of the water were studied. The results of physical-chemical analyses indicated similar habitat conditions for both species. Despite smaller dry weight C. polyacantha was characterized by greater morphological variability and higher rates of growth and percentage share of calcium carbonate in dry mass than C. rudis. The percentage of calcium carbonates in dry mass did not differ significantly between the species and exceeded 60%, reaching the maximum (76% in C. polyacantha in July and August. For both species, distinct correlations between the structure of biomass and morphological features were found. The obtained results show the great importance of charophyte vegetation in carbon cycling and functioning of lake ecosystems.

  14. Clear Cells of Toker in the Developing Anogenital Region of Male and Female Fetuses

    NARCIS (Netherlands)

    van der Putte, Sebastian C. J.

    2011-01-01

    The clear cells of Toker are a mysterious population of intra-epidermal glandular cells. They were originally described in nipples, but were recently observed in the vulva as well. It was hypothesized that intra-epidermal embryonic remnants or underlying glands were a potential source. The embryolog

  15. Remote sensing estimation of the total phosphorus concentration in a large lake using band combinations and regional multivariate statistical modeling techniques.

    Science.gov (United States)

    Gao, Yongnian; Gao, Junfeng; Yin, Hongbin; Liu, Chuansheng; Xia, Ting; Wang, Jing; Huang, Qi

    2015-03-15

    Remote sensing has been widely used for ater quality monitoring, but most of these monitoring studies have only focused on a few water quality variables, such as chlorophyll-a, turbidity, and total suspended solids, which have typically been considered optically active variables. Remote sensing presents a challenge in estimating the phosphorus concentration in water. The total phosphorus (TP) in lakes has been estimated from remotely sensed observations, primarily using the simple individual band ratio or their natural logarithm and the statistical regression method based on the field TP data and the spectral reflectance. In this study, we investigated the possibility of establishing a spatial modeling scheme to estimate the TP concentration of a large lake from multi-spectral satellite imagery using band combinations and regional multivariate statistical modeling techniques, and we tested the applicability of the spatial modeling scheme. The results showed that HJ-1A CCD multi-spectral satellite imagery can be used to estimate the TP concentration in a lake. The correlation and regression analysis showed a highly significant positive relationship between the TP concentration and certain remotely sensed combination variables. The proposed modeling scheme had a higher accuracy for the TP concentration estimation in the large lake compared with the traditional individual band ratio method and the whole-lake scale regression-modeling scheme. The TP concentration values showed a clear spatial variability and were high in western Lake Chaohu and relatively low in eastern Lake Chaohu. The northernmost portion, the northeastern coastal zone and the southeastern portion of western Lake Chaohu had the highest TP concentrations, and the other regions had the lowest TP concentration values, except for the coastal zone of eastern Lake Chaohu. These results strongly suggested that the proposed modeling scheme, i.e., the band combinations and the regional multivariate

  16. Sensitivity of lake ice regimes to climate change in the Nordic region

    Science.gov (United States)

    Gebre, S.; Boissy, T.; Alfredsen, K.

    2014-08-01

    A one-dimensional process-based multi-year lake ice model, MyLake, was used to simulate lake ice phenology and annual maximum lake ice thickness for the Nordic region comprising Fennoscandia and the Baltic countries. The model was first tested and validated using observational meteorological forcing on a candidate lake (Lake Atnsjøen) and using downscaled ERA-40 reanalysis data set. To simulate ice conditions for the contemporary period of 1961-2000, the model was driven by gridded meteorological forcings from ERA-40 global reanalysis data downscaled to a 25 km resolution using the Rossby Centre Regional Climate Model (RCA). The model was then forced with two future climate scenarios from the RCA driven by two different general circulation models (GCMs) based on the Special Report on Emissions Scenarios (SRES) A1B. The two climate scenarios correspond to two future time periods namely the 2050s (2041-2070) and the 2080s (2071-2100). To take into account the influence of lake morphometry, simulations were carried out for four different hypothetical lake depths (5 m, 10 m, 20 m, 40 m) placed at each of the 3708 grid cells. Based on a comparison of the mean predictions in the future 30-year periods with the control (1961-1990) period, ice cover durations in the region will be shortened by 1 to 11 weeks in 2041-2070, and 3 to 14 weeks in 2071-2100. Annual maximum lake ice thickness, on the other hand, will be reduced by a margin of up to 60 cm by 2041-2070 and up to 70 cm by 2071-2100. The simulated changes in lake ice characteristics revealed that the changes are less dependent on lake depths though there are slight differences. The results of this study provide a regional perspective of anticipated changes in lake ice regimes due to climate warming across the study area by the middle and end of this century.

  17. Sensitivity of lake ice regimes to climate change in the nordic region

    Directory of Open Access Journals (Sweden)

    S. Gebre

    2013-03-01

    Full Text Available A one-dimensional process-based multi-year lake ice model, MyLake, was used to simulate lake ice phenology and annual maximum lake ice thickness for the Nordic region comprising Fennoscandia and the Baltic countries. The model was first tested and validated using observational meteorological forcing on a candidate lake (Lake Atnsjøen and using downscaled ERA-40 reanalysis data set. To simulate ice conditions for the contemporary period of 1961–2000, the model was driven by gridded meteorological forcings from ERA-40 global reanalysis data downscaled to a 25 km resolution using the Rossby Center Regional Climate Model (RCA. The model was then forced with two future climate scenarios from the RCA driven by two different GCMs based on the SRES A1B emissions scenario. The two climate scenarios correspond to two future time periods namely the 2050s (2041–2070 and the 2080s (2071–2100. To take into account the influence of lake morphometry, simulations were carried out for four different hypothetical lake depths (5 m, 10 m, 20 m, 40 m placed at each of the 3708 grid cells. Based on a comparison of the mean predictions in the future 30 yr periods with the control (1961–1990 period, ice cover durations in the region will be shortened by 1 to 11 weeks in 2041–2070, and 3 to 14 weeks in 2071–2100. Annual maximum lake ice thickness, on the other hand, will be reduced by a margin of up to 60 cm by 2041–2070 and up to 70 cm by 2071–2100. The simulated changes in lake ice characteristics revealed that the changes are less dependent on lake depths though there are slight differences. The results of this study provide a~regional perspective of anticipated changes in lake ice regimes due to climate warming across the study area by the middle and end of this century.

  18. The mesoproterozoic midcontinent rift system, Lake Superior region, USA

    Science.gov (United States)

    Ojakangas, R.W.; Morey, G.B.; Green, J.C.

    2001-01-01

    Exposures in the Lake Superior region, and associated geophysical evidence, show that a 2000 km-long rift system developed within the North American craton ??? 1109-1087 Ma, the age span of the most of the volcanic rocks. This system is characterized by immense volumes of mafic igneous rocks, mostly subaerial plateau basalts, generated in two major pulses largely by a hot mantle plume. A new ocean basin was nearly formed before rifting ceased, perhaps due to the remote effect of the Grenville continental collision to the east. Broad sagging/subsidence, combined with a system of axial half-grabens separated along the length of the rift by accommodation zones, provided conditions for the accumulation of as much as 20 km of volcanic rocks and as much as 10 km of post-rift clastic sediments, both along the rift axis and in basins flanking a central, post-volcanic horst. Pre-rift mature, quartzose sandstones imply little or no uplift prior to the onset of rift volcanism. Early post-rift red-bed sediments consist almost entirely of intrabasinally derived volcanic sediment deposited in alluvial fan to fluvial settings; the exception is one gray to black carbon-bearing lacustrine(?) unit. This early sedimentation phase was followed by broad crustal sagging and deposition of progressively more mature red-bed, fluvial sediments with an extra-basinal provenance. ?? 2001 Elsevier Science B.V. All rights reserved.

  19. ANALYSIS OF MERCURY IN VERMONT AND NEW HAMPSHIRE LAKES: EVALUATION OF THE REGIONAL MERCURY CYCLING MODEL

    Science.gov (United States)

    An evaluation of the Regional Mercury Cycling Model (R-MCM, a steady-state fate and transport model used to simulate mercury concentrations in lakes) is presented based on its application to a series of 91 lakes in Vermont and New Hampshire. Visual and statistical analyses are pr...

  20. Regional impacts of ultrafine particle emissions from the surface of the Great Lakes

    Directory of Open Access Journals (Sweden)

    S. H. Chung

    2011-05-01

    Full Text Available Quantifying the impacts of aerosols on climate requires a detailed knowledge of both the anthropogenic and the natural contributions to the aerosol population. Recent work has suggested a previously unrecognized natural source of ultrafine particles resulting from breaking waves at the surface of large freshwater lakes. This work is the first modeling study to investigate the potential for this newly discovered source to affect the aerosol number concentrations on regional scales. Using the WRF-Chem modeling framework, the impacts of wind-driven aerosol production from the surface of the Great Lakes were studied for a July 2004 test case. Simulations were performed for a base case with no lake surface emissions, a case with lake surface emissions included, and a default case wherein large freshwater lakes emit marine particles as if they were oceans. Results indicate that the lake surface emissions can enhance the surface level aerosol number concentration by ∼20 % over the remote northern Great Lakes and by ∼5 % over other parts of the Great Lakes. These results were highly sensitive the nucleation parameterization within WRF-Chem; when the nucleation process was deactivated, surface-layer enhancements from the lake emissions increased to as much as 200 %. The results reported here have significant uncertainties associated with the lake emission parameterization and the way ultrafine particles are modeled within WRF-Chem. Nevertheless, the magnitude of the impacts found in this study suggest that further study of this phenomena is merited.

  1. Parallel Solver for Diffuse Optical Tomography on Realistic Head Models with Scattering and Clear Regions.

    Science.gov (United States)

    Placati, Silvio; Guermandi, Marco; Samore, Andrea; Franchi Scarselli, Eleonora; Guerrieri, Roberto

    2015-11-26

    Diffuse Optical Tomography is an imaging technique based on evaluating how light propagates within the human head to obtain functional information about the brain. Precision in reconstructing such an optical properties map is highly affected by the accuracy of the light propagation model implemented, which needs to take into account the presence of clear and scattering tissues. We present a numerical solver based on the radiosity-diffusion model integrating the anatomical information provided by a structural MRI. The solver is designed to run on parallel heterogeneous platforms based on multiple GPUs and CPUs. We demonstrate how the solver provides a 7x speed-up over an isotropic-scattered parallel Monte Carlo engine based on a Radiative Transport Equation for a domain composed of 2 millions voxels, along with a significant improvement in accuracy. The speed-up greatly increases for larger domains, allowing us to compute the light distribution of a full human head ( 3 million voxels) in 116 seconds for the platform used.

  2. The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

    Science.gov (United States)

    van der Schriek, Tim; Giannakopoulos, Christos

    2014-05-01

    The Mediterranean stands out globally due to its sensitivity to (future) climate change, with future projections predicting an increase in excessive drought events and declining rainfall. Regional freshwater ecosystems are particularly threatened: precipitation decreases, while extreme droughts increase and human impacts intensify (e.g. water extraction, drainage, pollution and dam-building). Many Mediterranean lake-wetland systems have shrunk or disappeared over the past two decades. Protecting the remaining systems is extremely important for supporting global biodiversity and for ensuring sustainable water availability. This protection should be based on a clear understanding of lake-wetland hydrological responses to natural and human-induced changes, which is currently lacking in many parts of the Mediterranean. The interconnected Prespa-Ohrid Lake system is a global hotspot of biodiversity and endemism. The unprecedented fall in water level (~8m) of Lake Megali Prespa threatens this system, but causes remain debated. Modelling suggests that the S Balkan will experience rainfall and runoff decreases of ~30% by 2050. However, projections revealing the potential impact of these changes on future lake level are unavailable as lake regime is not understood. A further drop in lake level may have serious consequences. The Prespa Lakes contribute ~25% of the total inflow into Lake Ohrid through underground karst channels; falling lake levels decrease this discharge. Lake Ohrid, in turn, feeds the Drim River. This entire catchment may therefore be affected by falling lake levels; its water resources are of great importance for Greece, Albania, FYROM and Montenegro (e.g. tourism, agriculture, hydro-energy, urban & industrial use). This new work proves that annual water level fluctuations of Lake Megali Prespa are predominantly related to precipitation during the first 7 months (Oct-Apr) of the hydrological year (Oct-Sep). Lake level is very sensitive to regional and

  3. Regional distribution and relevance in paleonvironmental studies of lakes in the Tatra Mts. (Western Carpathians

    Directory of Open Access Journals (Sweden)

    Joanna POCIASK-KARTECZKA

    2014-11-01

    Full Text Available Scientific limnological research in the Tatra Mountains were initiated by Stanislaw Staszic in the early XIX century.  After the World War II, the evolution of Tatra lakes was investigated by Kondracki, Klimaszewski, Baumgart-Kotarba and. Extensive paleolimnological investigations in the Tatra Mountains were started by the group of scientists led by K. Starmach in the beginning of the second half of the 20th century. There has been not much research concerned to the regional distribution of lakes and their properties in the Tatra Mountains (Pociask-Karteczka 2013. Very early division of lakes presented A. Gadomski (1922, which distinguished four types of lakes: a tarns (cirque lake or corrie loch, b bedrock-dammed lakes, c moraine lakes. This division was concerned in subsequent publications (Choiński 2007. M. Lukniš (1973, 1985 recognized additional types: kettles and landslide-dammed lakes and M. Klimaszewski (1988 – inter-sheepback lakes. J. Pacl and K. Wit-Jóźwik in Klima Tatier (Pacl, Wit-Jóźwik 1974 were focused on the temperature of water in lakes in Polish and Slovak parts and M. Borowiak (2000a,b provided a comprehensive analysis of types, dimensions, temperature and chemical composition of water in lakes in the Tatra Mountains.According to present day state of knowledge, one may distinguish following genetic types of lakes: I glacial, II not-glacial. There are four types of the glacial origin lakes in the Tatra Mountains (Fig. 1: a tarns (cirque lakes or corrie loch, b bedrock-moraine dammed lakes, c inter-sheepback lakes, d moraine lakes, e kettles.Most of lakes in the Tatra Mountains are tarns and bedrock-moraine dammed lakes, and they are located at the elevation over 1400 m a.s.l. in the Western Tatra Mountains, and over 1600 m a.s.l. in the High Tatra Mountains. Some of them are paternoster lakes – a series of stair-stepped lakes formed in individual rock basins aligned down the course of a glaciated valley. Lakes in

  4. Effects of land use on lake nutrients: The importance of scale, hydrologic connectivity, and region

    Science.gov (United States)

    Soranno, Patricia A.; Cheruvelil, Kendra Spence; Wagner, Tyler; Webster, Katherine E.; Bremigan, Mary Tate

    2015-01-01

    Catchment land uses, particularly agriculture and urban uses, have long been recognized as major drivers of nutrient concentrations in surface waters. However, few simple models have been developed that relate the amount of catchment land use to downstream freshwater nutrients. Nor are existing models applicable to large numbers of freshwaters across broad spatial extents such as regions or continents. This research aims to increase model performance by exploring three factors that affect the relationship between land use and downstream nutrients in freshwater: the spatial extent for measuring land use, hydrologic connectivity, and the regional differences in both the amount of nutrients and effects of land use on them. We quantified the effects of these three factors that relate land use to lake total phosphorus (TP) and total nitrogen (TN) in 346 north temperate lakes in 7 regions in Michigan, USA. We used a linear mixed modeling framework to examine the importance of spatial extent, lake hydrologic class, and region on models with individual lake nutrients as the response variable, and individual land use types as the predictor variables. Our modeling approach was chosen to avoid problems of multi-collinearity among predictor variables and a lack of independence of lakes within regions, both of which are common problems in broad-scale analyses of freshwaters. We found that all three factors influence land use-lake nutrient relationships. The strongest evidence was for the effect of lake hydrologic connectivity, followed by region, and finally, the spatial extent of land use measurements. Incorporating these three factors into relatively simple models of land use effects on lake nutrients should help to improve predictions and understanding of land use-lake nutrient interactions at broad scales.

  5. Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Torrey, M S

    1976-05-01

    The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.

  6. Investigations on the "Extreme" Microbial Arsenic Cycle within the Sediments of an Acidic Impoundment of the Former Sulfur Bank Mercury Mine: Herman Pit, Clear Lake, California.

    Science.gov (United States)

    Blum, J. S.; Hoeft McCann, S. E.; Bennett, S.; Miller, L. G.; Stoneburner, B.; Saltikov, C.; Oremland, R. S.

    2014-12-01

    The involvement of prokaryotes in the redox reactions of arsenic occurring between this element's +5 [arsenate; As(V)] and + 3 [arsenite; As(III)] oxidation states has been well established. Most research has focused upon circum-neutral pH environments, such as freshwater lake and aquifer sediments, and extreme environments like hot springs and hypersaline soda lakes have also been well investigated. In contrast, little work has been conducted on acidic environments. The azure-hued, clear waters of the Herman Pit are acidic (pH 2-4), and overlie oxidized sediments that have a distinctive red/orange coloration indicative of the presence of ferrihydrites and other Fe(III) minerals. There is extensive ebullitive release of geothermal gases from the lake bottom in the form of numerous continuous-flow seeps which are composed primarily of mixtures of CO2, CH4, and H2S. We collected near-shore surface sediments with an Eckman grab, and stored the "soupy" material in filled mason jars kept at 4˚C. Initial experiments were conducted using 3:1 mixtures of lake water: sediment so as to generate dilute slurries which were amended with mM levels of electron acceptors (arsenate, nitrate, oxygen), electron donors (arsenite, acetate, lactate, hydrogen), and incubated under N2, air, or H2. Owing to the large adsorptive capacity of the Fe(III)-rich slurries, we were unable to detect As(V) or As(III) in the aqueous phase of either live or autoclaved controls, although the former consumed lactate, acetate, nitrate, or hydrogen, while the latter did not. This prompted us to conduct a series of further diluted slurry experiments using the live materials from the first as a 10 % addition to lakewater. In these experiments we observed reduction of As(V) to As(III) in anoxic slurries and that rates were enhanced by addition of electron donors (H2, acetate, or lactate). We also observed oxidation of As(III) to As(V) in oxic slurries and in anoxic slurries amended with nitrate. These

  7. Application of Landsat 8 imagery to regional-scale assessment of lake water quality

    Science.gov (United States)

    Andrzej Urbanski, Jacek; Wochna, Agnieszka; Bubak, Iwona; Grzybowski, Waldemar; Lukawska-Matuszewska, Katarzyna; Łącka, Magda; Śliwińska, Sylwia; Wojtasiewicz, Bożena; Zajączkowski, Marek

    2016-09-01

    The aim of the project was to create a tool with which to support regional lake quality assessment using Landsat 8 imagery data. The model of assigning the ecological status was implemented in GIS for the northern part of Poland and classifies lake quality for several classes according to classification of WFD using two basic assumptions. The first is that there exists a combination of OLI bands (OLI2/OLI4 was used) which correlates well with the trophic state of the lakes; the second assumption is that the reference trophic state depends on the mean depth of the lake. The model uses a lake geodatabase which contains lakes outlines, raster masks of lakes and attribute information about their mean depth. There is no need to provide any field data when using this tool, as calibration of the model is done using subsets of lakes which were classified using legally defined methods. The tool allows fast classification of 2800 lakes from the area of interest. The results show good agreement between satellite and expert based methods.

  8. Mapping landslide processes in the North Tanganyika - Lake Kivu rift zones: towards a regional hazard assessment

    Science.gov (United States)

    Dewitte, Olivier; Monsieurs, Elise; Jacobs, Liesbet; Basimike, Joseph; Delvaux, Damien; Draida, Salah; Hamenyimana, Jean-Baptiste; Havenith, Hans-Balder; Kubwimana, Désiré; Maki Mateso, Jean-Claude; Michellier, Caroline; Nahimana, Louis; Ndayisenga, Aloys; Ngenzebuhoro, Pierre-Claver; Nkurunziza, Pascal; Nshokano, Jean-Robert; Sindayihebura, Bernard; Philippe, Trefois; Turimumahoro, Denis; Kervyn, François

    2015-04-01

    The mountainous environments of the North Tanganyika - Lake Kivu rift zones are part of the West branch of the East African Rift. In this area, natural triggering and environmental factors such as heavy rainfalls, earthquake occurrences and steep topographies favour the concentration of mass movement processes. In addition anthropogenic factors such as rapid land use changes and urban expansion increase the sensibility to slope instability. Until very recently few landslide data was available for the area. Now, through the initiation of several research projects and the setting-up of a methodology for data collection adapted to this data-poor environment, it becomes possible to draw a first regional picture of the landslide hazard. Landslides include a wide range of ground movements such as rock falls, deep failure of slopes and shallow debris flows. Landslides are possibly the most important geohazard in the region in terms of recurring impact on the populations, causing fatalities every year. Many landslides are observed each year in the whole region, and their occurrence is clearly linked to complex topographic, lithological and vegetation signatures coupled with heavy rainfall events, which is the main triggering factor. Here we present the current knowledge of the various slope processes present in these equatorial environments. A particular attention is given to urban areas such as Bukavu and Bujumbura where landslide threat is particularly acute. Results and research perspectives on landslide inventorying, monitoring, and susceptibility and hazard assessment are presented.

  9. Regional Analysis of the Hazard Level of Glacial Lakes in the Cordillera Blanca, Peru

    Science.gov (United States)

    Chisolm, Rachel E.; Jhon Sanchez Leon, Walter; McKinney, Daene C.; Cochachin Rapre, Alejo

    2016-04-01

    The Cordillera Blanca mountain range is the highest in Peru and contains many of the world's tropical glaciers. This region is severely impacted by climate change causing accelerated glacier retreat. Secondary impacts of climate change on glacier retreat include stress on water resources and the risk of glacial lake outburst floods (GLOFs) from the many lakes that are forming and growing at the base of glaciers. A number of GLOFs originating from lakes in the Cordillera Blanca have occurred over the last century, several of which have had catastrophic impacts on cities and communities downstream. Glaciologists and engineers in Peru have been studying the lakes of the Cordillera Blanca for many years and have identified several lakes that are considered dangerous. However, a systematic analysis of all the lakes in the Cordillera Blanca has never before been attempted. Some methodologies for this type of systematic analysis have been proposed (eg. Emmer and Vilimek 2014; Wang, et al. 2011), but as yet they have only been applied to a few select lakes in the Cordillera Blanca. This study uses remotely sensed data to study all of the lakes of the Glacial Lake Inventory published by the Glaciology and Water Resources Unit of Peru's National Water Authority (UGRH 2011). The objective of this study is to assign a level of potential hazard to each glacial lake in the Cordillera Blanca and to ascertain if any of the lakes beyond those that have already been studied might pose a danger to nearby populations. A number of parameters of analysis, both quantitative and qualitative, have been selected to assess the hazard level of each glacial lake in the Cordillera Blanca using digital elevation models, satellite imagery, and glacier outlines. These parameters are then combined to come up with a preliminary assessment of the hazard level of each lake; the equation weighting each parameter draws on previously published methodologies but is tailored to the regional characteristics

  10. Water Quality and Evaluation of Pesticides in Lakes in the Ridge Citrus Region of Central Florida

    Science.gov (United States)

    Choquette, Anne F.; Kroening, Sharon E.

    2009-01-01

    Water chemistry, including major inorganic constituents, nutrients, and pesticide compounds, was compared between seven lakes surrounded by citrus agriculture and an undeveloped lake on the Lake Wales Ridge (herein referred to as the Ridge) in central Florida. The region has been recognized for its vulnerability to the leaching of agricultural chemicals into the subsurface due to factors including soils, climate, and land use. About 40 percent of Florida's citrus cultivation occurs in 'ridge citrus' areas characterized by sandy well drained soils, with the remainder in 'flatwoods citrus' characterized by high water tables and poorly drained soils. The lakes on the Ridge are typically flow-through lakes that exchange water with adjacent and underlying aquifer systems. This study is the first to evaluate the occurrence of pesticides in lakes on the Ridge, and also represents one of the first monitoring efforts nationally to focus on regional-scale assessment of current-use pesticides in small- to moderate-sized lakes (5 to 393 acres). The samples were collected between December 2003 and September 2005. The lakes in citrus areas contained elevated concentrations of major inorganic constituents (including alkalinity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, and sulfate), total nitrogen, pH, and pesticides compared to the undeveloped lake. Nitrate (as N) and total nitrogen concentrations were typically elevated in the citrus lakes, with maximum values of 4.70 and 5.19 mg/L (milligrams per liter), respectively. Elevated concentrations of potassium, nitrate, and other inorganic constituents in the citrus lakes likely reflect inputs from the surficial ground-water system that originated predominantly from agricultural fertilizers, soil amendments, and inorganic pesticides. A total of 20 pesticide compounds were detected in the lakes, of which 12 compounds exceeded the standardized reporting level of 0.06 ug/L (microgram per liter). Those

  11. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    Science.gov (United States)

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  12. Environmental status of the Lake Michigan region. Volume 6. Zoobenthos of Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Mozley, S.C.; Howmiller, R.P.

    1977-09-01

    This report summarizes Lake Michigan zoobenthic studies up to 1974, including reports of power-plant surveys. It describes ecologies of macroinvertebrate species and some microfauna, partly through use of data from other Great Lakes. The following are discussed: methodology of field surveys; zoobenthic indicators of pollution; zoobenthic effects on sediment-water exchanges; and numbers, biomass, and production of total macroinvertebrates. Prominent features of Lake Michigan zoobenthos include predominance of the amphipod Pontoporeia affinis, usefulness of tubificid oligochaetes in mapping environmental quality, and pronounced qualitative gradients in zoobenthos in relation to depth. Further research is needed on sampling methods, energy flow rates and pathways through benthic communities, factors limiting distribution of species near shore, and effects of macroinvertebrates on sediment chemistry and structure.

  13. Regional impacts of ultrafine particle emissions from the surface of the Great Lakes

    Directory of Open Access Journals (Sweden)

    S. H. Chung

    2011-12-01

    Full Text Available Quantifying the impacts of aerosols on climate requires a detailed knowledge of both the anthropogenic and the natural contributions to the aerosol population. Recent work has suggested a previously unrecognized natural source of ultrafine particles resulting from breaking waves at the surface of large freshwater lakes. This work is the first modeling study to investigate the potential for this newly discovered source to affect the aerosol number concentrations on regional scales. Using the WRF-Chem modeling framework, the impacts of wind-driven aerosol production from the surface of the Great Lakes were studied for a July 2004 test case. Simulations were performed for a base case with no lake surface emissions, a case with lake surface emissions included, and a default case wherein large freshwater lakes emit marine particles as if they were oceans. Results indicate that the lake surface emissions can enhance the surface-level aerosol number concentration by ~20% over the remote northern Great Lakes and by ~5% over other parts of the Great Lakes. These results were highly sensitive to the new particle formation (i.e., nucleation parameterization within WRF-Chem; when the new particle formation process was deactivated, surface-layer enhancements from the lake emissions increased to as much as 200%. The results reported here have significant uncertainties associated with the lake emission parameterization and the way ultrafine particles are modeled within WRF-Chem. Nevertheless, the magnitudes of the impacts found in this study suggest that further study to quantify the emissions of ultrafine particles from the surface of the Great Lakes is merited.

  14. Deep drilling of ancient Lake Ohrid (Balkan region) to capture over 1 million years of evolution and global climate cycling

    Science.gov (United States)

    Wagner, Bernd; Francke, Alexander; Wilke, Thomas; Krastel, Sebastian; Zanchetta, Giovanni; Sulpizio, Roberto; Reicherter, Klaus; Leng, Melanie; Grazhdani, Andon; Trajanovski, Sasho; Levkov, Zlatko; Reed, Jane; Wonik, Thomas

    2014-05-01

    Ancient lakes, with sediment records spanning >1 million years, are very rare. The UNESCO World Heritage site of Lake Ohrid in the Balkan region is thought to be the oldest lake in continuous existence in Europe and, with 212 endemic species described to date, is a hotspot of evolution. An international group of scientists working on a project entitled 'Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO)' realized a deep drilling campaign of Lake Ohrid in spring 2013. Based on several coring seismic campaigns between 2004 and 2011, Lake Ohrid became the target of an ICDP deep drilling campaign, with specific research aims: (i) obtain precise information about the age and origin of the lake, (ii) unravel the lake's seismotectonic history, (iii) obtain a continuous record of Quaternary volcanic activity and climate change, and (iv) investigate the influence of major geological/environmental events on evolution and the generation of extraordinary endemic biodiversity. Drilling began in April 2013 using the Deep Lake Drilling System (DLDS) of DOSECC (USA). The campaign, completed by late May, was deemed one of the most successful ICDP lake drilling projects, with a total of ~2100 m of sediment recovered from four different sites. At the central "DEEP" site, hydro-acoustic data indicated a maximum sediment fill of ca. 700 m, of which the uppermost 568 m was recovered. Coarse gravel and pebbles underlying clay and shallow water facies hampered deeper penetration. A total of 1526 m of sediment cores was collected from six boreholes, with a composite field recovery ('master core') of 544 m (95%). Three additional sites were drilled in order to analyze lake-level fluctuations, catchment dynamics, biodiversity and evolution processes ("Cerava", deepest drilled depth: 90 m), to investigate active tectonics and spring dynamics ("Gradiste", deepest drilled depth: 123 m), and to try to understand the geological origins of the Ohrid Basin ("Pestani

  15. [Spatial Distribution of Stable Isotope from the Lakes in Typical Temperate Glacier Region].

    Science.gov (United States)

    Shi, Xiao-yi; Pu, Tao; He, Yuan-qing; Lu, Hao; Niu, He-wen; Xia, Dun-sheng

    2016-05-15

    We focused mainly on the spatial variation and influencing factors of hydrogen and oxygen stable isotopes between water samples collected at the surface and different depths in the Lashi Lake in August, 2014. Hydrological supply characteristics of the lake in typical temperate glacier region were discussed. The results showed that the values of δ¹⁸O and δD in the Lashi Lake ranged from -12.98 per thousand to -8.16 per thousand with the mean of -9.75 per thousand and from -99.42 per thousand to -73.78 per thousand with the mean of -82.23 per thousand, respectively. There was a reversed spatial variation between δ¹⁸O and d. Relatively low values of δ¹⁸O with high values of d were found at the edge of the lake where the rivers drained into. Meanwhile, the values of d in the vertical profile varied little with depth, suggesting that the waters mixed sufficiently in the vertical direction. The d values increased at first and then decreased from east to west at different layers, but both increase and decrease exhibited different velocities, which were related to the river distribution, the locality of the lake and environmental conditions etc. River water and atmospheric precipitation were the main recharge sources of the Lashi Lake, and the melt-water of snow and ice might also be the supply resource. The δ¹⁸O values of lake water in glacier region decreased along the elevation (except for Lashi Lake), generally, this phenomenon was called "altitude effect". Moreover, high isotopic values of the lake water from non-glacier region were due to the evaporation effect.

  16. Use of Atmospheric Infrared Sounder clear-sky and cloud-cleared radiances in the Weather Research and Forecasting 3DVAR assimilation system for mesoscale weather predictions over the Indian region

    Science.gov (United States)

    Singh, Randhir; Kishtawal, C. M.; Pal, P. K.

    2011-11-01

    A set of assimilation experiments is conducted with the Three-Dimensional Variational (3DVAR) data assimilation system associated with the Weather Research and Forecasting (WRF) model. The purpose of the investigation is to assess the impact on forecast skill in response to assimilation of the Atmospheric Infrared Sounder (AIRS) clear-sky and cloud-cleared radiances over the Indian region. This is the first study that makes use of cloud-cleared radiances in the WRF system. Two sets of thirty-one 72 h forecasts are performed, all initialized at 00:00 UTC each day throughout the month of July 2010, to compare the model performance consequent to assimilation of clear-sky versus cloud-cleared radiances. A rigorous validation is produced against National Centers for Environmental Prediction analyzed wind, temperature, and moisture. In addition, the precipitation forecast skill is assessed against Tropical Rainfall Measuring Mission observations. The results show improvement in forecast skill consequent to the assimilation of cloud-cleared radiances (CCR). The implications of using CCR for operational weather forecasting appear to be significant. Since only a small fraction of AIRS channels are cloud-free, information obtained in cloudy regions, which is meteorologically very significant, is lost when assimilating only clear-sky radiances (CSR). On the contrary, assimilation of CCR allows a larger yield, which leads to improved model performance. The assimilation of CCR resulted in significantly improved rainfall prediction compared to that obtained from the use of CSR. The finding of this study clearly shows the advantage of CCR available from clear-sky as well as from partly cloudy regions as compared to CSR, which are available only in clear-sky regions.

  17. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Pentecost, E.D.; Vogt, R.C.

    1976-07-01

    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps.

  18. Great Lakes/St. Lawrence Seaway Regional Transportation Study; Great Lakes Area Industries.

    Science.gov (United States)

    1981-11-01

    in either vertical or horizontal rotary kilns . Most states have limestone deposits, but much of that used by the steel industry comes from Michigan...Others Amoco 3 National Gypsum 6 Cement Transit Company 7 Erie Sand 3 Subtotal 19 TOTAL 140 * I Source: Lake Carriers Association. I I III-21 I

  19. Regional economic impacts of water management alternatives: the case of Devils Lake, North Dakota, USA.

    Science.gov (United States)

    Leistritz, F Larry; Leitch, Jay A; Bangsund, Dean A

    2002-12-01

    Devils Lake, located in a closed basin in northeastern North Dakota has over a century-long history of highly fluctuating water levels. The lake has risen nearly 25 feet (7.7 m) since 1993, more than doubling its surface area. Rising water levels have affected rural lands, transportation routes, and communities near the lake. In response to rising lake levels, Federal, state and local agencies have adopted a three-part approach to flood damage reduction, consisting of (1) upper basin water management to reduce the amount of water reaching the lake, (2) protection for structures and infrastructure if the lake continues to rise, and (3) developing an emergency outlet to release some lake water. The purpose of this study was to provide information about the net regional economic effects of a proposed emergency outlet for Devils Lake. An input-output model was used to estimate the regional economic effects of the outlet, under two scenarios: (1) the most likely future situation (MLS) and (2) a best case situation (BCS) (i.e., where the benefits from the outlet would be greatest), albeit an unlikely one. Regional economic effects of the outlet include effects on transportation (road and railroad construction), agriculture (land kept in production, returned to production sooner, or kept in production longer), residential relocations, and outlet construction expenditures. Effects are measured as changes in gross business volume (gross receipts) for various sectors, secondary employment, and local tax collections. The net regional economic effects of the proposed outlet would be relatively small, and consideration of these economic impacts would not strengthen the case for an outlet.

  20. Empirical Relationships Between Watershed Attributes and Headwater Lake Chemistry in the Adirondack Region

    Energy Technology Data Exchange (ETDEWEB)

    Hunsaker, C.T.

    1987-01-01

    Surface water acidification may be caused or influenced by both natural watershed processes and anthropogenic actions. Empirical models and observational data can be useful for identifying watershed attributes or processes that require further research or that should be considered in the development of process models. This study focuses on the Adirondack region of New York and has two purposes: to (1) develop empirical models that can be used to assess the chemical status of lakes for which no chemistry data exist and (2) determine on a regional scale watershed attributes that account for variability in lake pH and acid-neutralizing capacity (ANC). Headwater lakes, rather than lakes linked to upstream lakes, were selected for initial analysis. The Adirondacks Watershed Data Base (AWDB), part of the Acid Deposition Data Network maintained at Oak Ridge National Laboratory (ORNL), integrates data on physiography, bedrock, soils, land cover, wetlands, disturbances, beaver activity, land use, and atmospheric deposition with the water chemistry and morphology for the watersheds of 463 headwater lakes. The AWD8 facilitates both geographic display and statistical analysis of the data. The report, An Adirondack Watershed Data Base: Attribute and Mapping Information for Regional Acidic Deposition Studies (ORNL/TM--10144), describes the AWDB. Both bivariate (correlations and Wilcoxon and Kruskal-Wallis tests) and multivariate analyses were performed. Fifty-seven watershed attributes were selected as input variables to multiple linear regression and discriminant analysis. For model development -200 lakes for which pH and ANC data exist were randomly subdivided into a specification and a verification data set. Several indices were used to select models for predicting lake pH (31 variables) and ANC (27 variables). Twenty-five variables are common to the pH and ANC models: four lake morphology, nine soil/geology, eight land cover, three disturbance, and one watershed aspect. An

  1. Holocene volcanic rocks in Jingbo Lake region--Diversity of magmatism

    Institute of Scientific and Technical Information of China (English)

    FAN Qicheng; SUN Qian; LI Ni; WANG Tuanhua

    2006-01-01

    During the time from 5500 a to 5200 a BP more than 10 Holocene volcanoes in Jingbo Lake region erupted and the volcanic rocks covered an area of about 500 km2. Holocene volcanic rocksin Jingbo Lake region belong to the potassium-rich rocks and contain three rock types: trachybasalts, basanites and phonotephrites. Various types of magmatism formed in a small area and in a short period of time came from partial melting of potassically-metasomatised lithospheric mantle. The diversity of magmatism can be explained by that Jingbo Lake is situated in the back-arc extensional region of East Asian continent subducted by the Pacific Ocean, and potassic fluid derived from mantle wedge or dehydration of subducted slab can result in a high heterogeneity of the mantle beneath this region. Based on the pressure estimation of clinopyroxene megacrysts, we estimate that phonotephrite magma fractionally crystallize at ca. 52-54 km down the earth.

  2. Environmental status of the Lake Michigan region. Volume 14. Birds of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, G.J.

    1977-07-01

    This report characterizes the bird life found in 100 counties of the four states peripheral to Lake Michigan. It discusses major habitats (the Lake Michigan shoreline, inland lakes, rivers and streams, marshes, fields and open spaces, and woodlots) and associates specific birds with habitats according to preferences for space and food. It also discusses the special attributes of state parks and lakeshores, refuges and sanctuaries, and other special areas which are attractive to avifauna. Patterns of historical occurrence and abundance, and the influence of pesticides and pollution, disease, and hunting pressure are explored to place present occurrence in a modern perspective. Migration patterns are discussed to explain increases and decreases which occur in nonresident avifauna of the Basin. The distribution and habits of birds that occur regularly in the Basin are described in an annotated list; a more complete list is presented in a table which encapsulates data for rapid and convenient reference. Separate sections deal with extinct, extirpated, and introduced species, and with endangered, threatened, and declining species.

  3. The "Crystal Growth" of sustainable regional development - The example of the Lake Constance Agenda 21

    OpenAIRE

    Walser, Manfred; Scherer, Roland

    2002-01-01

    Implementing sustainable regional development by institutionalising a structure of responsibility can be compared with originating the growth of a crystal by introducing a nucleus in a chemical solution. This is the result of a top down initiated regional Agenda 21-process in the international Lake of Constance- region. The interplay between top down and bottom up activities as a precondition of success of regional development is part of the theoretical mainstream. But how the interplay will ...

  4. Clear & Simple

    Science.gov (United States)

    ... Cultural Respect Language Access Talking to Your Doctor Research Underway Plain Language Clear & Simple What is Clear & Simple? Clear & Simple ... schedule? A: Pretesting need not be an elaborate, time-consuming research project and depends on: How quickly you work, ...

  5. 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.

  6. N pollution sources and denitrification in waterbodies in Taihu Lake region

    Institute of Scientific and Technical Information of China (English)

    邢光熹; 曹亚澄; 施书莲; 孙国庆; 杜丽娟; 朱建国

    2001-01-01

    Herein presented are the researches of the past few years related to characteristics of N pollution of waterbodies and N transport from croplands to the waterbodies in Suzhou and Wuxi regions, the center of the Taihu Lake valley. Based on the types of waterbodies, concentrations ofinorganic N of different forms, concentrations of PO43-, δ15NH4 values in river and lake waterbodies,the pollution sources of N in the river, lake and well waters are distinguished, and comparisons are made of trend of variation and amplitude of concentration between years, seasons and N pollutants in waterbodies. The increase in N2O concentration in different waterbodies and high δ15NO3-value in different waterbodies are deemed as an evidence of the existence of denitrification in the river, lake and well waters. Moreover, the role of denitrification in the waterbodies plays in stabilizing chronically concentration of N as pollutant in the waterbodies and mitigating N load in the waterbodies.

  7. N pollution sources and denitrification in waterbodies in-Taihu Lake region

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Herein presented are the researches of the past few years related to characteristics of N pollution of waterbodies and N transport from croplands to the waterbodies in Suzhou and Wuxi regions, the center of the Taihu Lake valley. Based on the types of waterbodies, concentrations of inorganic N of different forms, concentrations of , d15NH4 values in river and lake waterbodies, the pollution sources of N in the river, lake and well waters are distinguished, and comparisons are made of trend of variation and amplitude of concentration between years, seasons and N pollutants in waterbodies. The increase in N2O concentration in different waterbodies and high d 15 value in different waterbodies are deemed as an evidence of the existence of denitrification in the river, lake and well waters. Moreover, the role of denitrification in the waterbodies plays in stabilizing chronically concentration of N as pollutant in the waterbodies and mitigating N load in the water-bodies.

  8. Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS.

    Directory of Open Access Journals (Sweden)

    Chrispine Nyamweya

    Full Text Available Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May and mixing (June-August. Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

  9. Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS).

    Science.gov (United States)

    Nyamweya, Chrispine; Desjardins, Christopher; Sigurdsson, Sven; Tomasson, Tumi; Taabu-Munyaho, Anthony; Sitoki, Lewis; Stefansson, Gunnar

    2016-01-01

    Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS) to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May) and mixing (June-August). Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza) and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents) that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

  10. Using a Coupled Lake Model with WRF to Improve High-Resolution Regional Climate Simulations

    Science.gov (United States)

    Mallard, M.; Bullock, R.; Nolte, C. G.; Alapaty, K.; Otte, T.; Gula, J.

    2012-12-01

    Lakes can play a significant role in regional climate by modifying air masses through fluxes of heat and moisture and by modulating inland extremes in temperature. Representing these effects becomes more important as regional climate modeling efforts employ finer grid spacing in order to simulate smaller scales. The Weather Research and Forecasting (WRF) model does not simulate lakes explicitly. Instead, lake points are treated as ocean points, with sea surface temperatures (SSTs) interpolated from the nearest neighboring ocean point in the driving coarse-scale fields. This can result in substantial errors for inland lakes such as the Great Lakes. Although prescribed lake surface temperatures (LSTs) can be used for retrospective modeling applications, this may not be desirable for applications involving downscaling future climate scenarios from a global climate model (GCM). In such downscaling simulations, lakes that impact the regional climate in the area of interest may not be resolved by the coarser global input fields. Explicitly simulating the LST would allow WRF to better represent interannual variability in regions significantly affected by lakes, and the influence of such variability on temperature and precipitation patterns. Therefore, coupling a lake model to WRF may lead to more reliable assessments of the impacts of extreme events on human health and the environment. We employ a version of WRF coupled to the Freshwater Lake model, FLake (Gula and Peltier 2012). FLake is a 1D bulk lake model which provides updated LSTs and ice coverage throughout the integration. This two-layer model uses a temperature-depth profile which includes a homogeneous mixed layer at the surface and a thermocline below. The shape of the thermocline is assumed, based on past theoretical and observational studies. Therefore, additional variables required for FLake to run are minimal, and it does not require tuning for individual lakes. These characteristics are advantageous for a

  11. Lake Vanda: A sentinel for climate change in the McMurdo Sound Region of Antarctica

    Science.gov (United States)

    Castendyk, Devin N.; Obryk, Maciej K.; Leidman, Sasha Z.; Gooseff, Michael; Hawes, Ian

    2016-09-01

    Lake Vanda is a perennially ice-covered, meromictic, endorheic lake located in the McMurdo Dry Valleys of Antarctica, and an exceptional sentinel of climate change within the region. Lake levels rose 15 m over the past 68 years in response to climate-driven variability in ice-cover sublimation, meltwater production, and annual discharge of the Onyx River, the main source of water to the lake. Evidence from a new bathymetric map and water balance model combined with annual growth laminations in benthic mats suggest that the most recent filling trend began abruptly 80 years ago, in the early 1930s. This change increased lake volume by > 50%, triggered the formation of a new, upper, thermohaline convection cell, and cooled the lower convection cell by at least 2 °C and the bottom-most waters by at > 4 °C. Additionally, the depth of the deep chlorophyll a maximum rose by > 2 m, and deep-growing benthic algal mats declined while shallow benthic mats colonized freshly inundated areas. We attribute changes in hydrology to regional variations in air flow related to the strength and position of the Amundsen Sea Low (ASL) pressure system which have increased the frequency of down-valley, föhn winds associated with surface air temperature warming in the McMurdo Dry Valleys. The ASL has also been implicated in the recent warming of the Antarctic Peninsula, and provides a common link for climate-related change on opposite sides of the continent. If this trend persists, Lake Vanda should continue to rise and cool over the next 200 years until a new equilibrium lake level is achieved. Most likely, future lake rise will lead to isothermal conditions not conducive to thermohaline convection, resulting in a drastically different physical, biogeochemical, and biological structure than observed today.

  12. Application of a comprehensive extraction technique for the determination of poly- and perfluoroalkyl substances (PFASs) in Great Lakes Region sediments.

    Science.gov (United States)

    Guo, Rui; Megson, David; Myers, Anne L; Helm, Paul A; Marvin, Chris; Crozier, Patrick; Mabury, Scott; Bhavsar, Satyendra P; Tomy, Gregg; Simcik, Matt; McCarry, Brian; Reiner, Eric J

    2016-12-01

    A comprehensive method to extract perfluoroalkane sulfonic acids (PFSAs), perfluoroalkyl carboxylic acids (PFCAs), polyfluoroalkyl phosphoric acid diesters (diPAPs), perfluoroalkyl phosphinic acids (PFPiAs) and perfluoroalkyl phosphonic acids (PFPAs) from sediment and analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and applied to sediment cores from three small isolated lakes (Plastic Lake, Lake 442, Lake Tettegouche) and Lake Ontario in the Great Lakes Region. Recoveries of the target compounds using the optimized acetonitrile/sodium hydroxide extraction ranged from 73% to 120%. The greatest concentrations of per- and polyfluorinated alkyl substances (PFASs) were recorded in sediment from Lake Ontario (ΣPFASs 13.1 ng/g), where perfluorooctane sulfonic acid (PFOS) contributed over 80% of the total. Concentrations in Lake Ontario were approximately 1-2 orders of magnitude greater than the more remote lakes subject to primarily atmospheric inputs. Whilst the PFAS contribution in Lake Ontario was dominated by PFOS, the more remote lakes contained sediment with higher proportions of PFCAs. Trace amounts of emerging PFASs (diPAPs and PFPiAs) were found in very recent surface Lake Ontario and remote lake sediments.

  13. Ex-Combatant Reintegration in the Great Lakes Region: Processes & Mechanisms, Trajectories & Paradoxes

    OpenAIRE

    Rhea, Randolph Wallace

    2016-01-01

    Since the early 1990’s, the Great Lakes Region (GLR) has been devastated by a wave of interconnected interstate, intrastate, and local conflicts involving hundreds of thousands of soldiers in dozens of armed groups. An important part of the international community’s approach to peacebuilding in the region has involved the disarmament, demobilization, and reintegration (DDR) of armed groups. Because of the transnational nature of many armed groups in the GLR, a regional approach to DDR has bee...

  14. Glial cell biology in the Great Lakes region.

    Science.gov (United States)

    Feinstein, Douglas L; Skoff, Robert P

    2016-03-31

    We report on the tenth bi-annual Great Lakes Glial meeting, held in Traverse City, Michigan, USA, September 27-29 2015. The GLG meeting is a small conference that focuses on current research in glial cell biology. The array of functions that glial cells (astrocytes, microglia, oligodendrocytes, Schwann cells) play in health and disease is constantly increasing. Despite this diversity, GLG meetings bring together scientists with common interests, leading to a better understanding of these cells. This year's meeting included two keynote speakers who presented talks on the regulation of CNS myelination and the consequences of stress on Schwann cell biology. Twenty-two other talks were presented along with two poster sessions. Sessions covered recent findings in the areas of microglial and astrocyte activation; age-dependent changes to glial cells, Schwann cell development and pathology, and the role of stem cells in glioma and neural regeneration.

  15. Regional nitrogen budget of the Lake Victoria Basin, East Africa: syntheses, uncertainties and perspectives

    Science.gov (United States)

    Zhou, Minghua; Brandt, Patric; Pelster, David; Rufino, Mariana C.; Robinson, Timothy; Butterbach-Bahl, Klaus

    2014-10-01

    Using the net anthropogenic nitrogen input (NANI) approach we estimated the N budget for the Lake Victoria Basin in East Africa. The NANI of the basin ranged from 887 to 3008 kg N km-2 yr-1 (mean: 1827 kg N km-2 yr-1) for the period 1995-2000. The net nitrogen release at basin level is due primarily to livestock and human consumption of feed and foods, contributing between 69% and 85%. Atmospheric oxidized N deposition contributed approximately 14% to the NANI of the Lake Victoria Basin, while either synthetic N fertilizer imports or biological N fixations only contributed less than 6% to the regional NANI. Due to the low N imports of feed and food products (export to Lake Victoria accounted for 16%, which is much lower than for watersheds located in Europe and USA (25%). A significant reduction of the uncertainty of our N budget estimate for Lake Victoria Basin would be possible if better data on livestock systems and riverine N export were available. Our study indicates that at present soil N mining is the main source of nitrogen in the Lake Victoria Basin. Thus, sustainable N management requires increasing agricultural N inputs to guarantee food security and rehabilitation and protection of soils to minimize environmental costs. Moreover, to reduce N pollution of the lake, improving management of human and animal wastes needs to be carefully considered in future.

  16. The regional and global significance of nitrogen removal in lakes and reservoirs

    Science.gov (United States)

    Harrison, J.A.; Maranger, R.J.; Alexander, R.B.; Giblin, A.E.; Jacinthe, P.-A.; Mayorga, Emilio; Seitzinger, S.P.; Sobota, D.J.; Wollheim, W.M.

    2009-01-01

    Human activities have greatly increased the transport of biologically available nitrogen (N) through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N year-1 from watersheds globally. Small lakes (global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially at the half-degree scale (0-100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain ~33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area:lake or reservoir surface area), higher apparent settling velocities for N, and greater average N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale. ?? 2008 Springer Science+Business Media B.V.

  17. Potential Effects of Climate Changes on Aquatic Systems: Laurentian Great Lakes and Precambrian Shield Region

    Science.gov (United States)

    Magnuson, J. J.; Webster, K. E.; Assel, R. A.; Bowser, C. J.; Dillon, P. J.; Eaton, J. G.; Evans, H. E.; Fee, E. J.; Hall, R. I.; Mortsch, L. R.; Schindler, D. W.; Quinn, F. H.

    1997-06-01

    The region studied includes the Laurentian Great Lakes and a diversity of smaller glacial lakes, streams and wetlands south of permanent permafrost and towards the southern extent of Wisconsin glaciation. We emphasize lakes and quantitative implications. The region is warmer and wetter than it has been over most of the last 12000 years. Since 1911 observed air temperatures have increased by about 0·11°C per decade in spring and 0·06°C in winter; annual precipitation has increased by about 2·1% per decade. Ice thaw phenologies since the 1850s indicate a late winter warming of about 2·5°C. In future scenarios for a doubled CO2 climate, air temperature increases in summer and winter and precipitation decreases (summer) in western Ontario but increases (winter) in western Ontario, northern Minnesota, Wisconsin and Michigan. Such changes in climate have altered and would further alter hydrological and other physical features of lakes. Warmer climates, i.e. 2 × CO2 climates, would lower net basin water supplies, stream flows and water levels owing to increased evaporation in excess of precipitation. Water levels have been responsive to drought and future scenarios for the Great Lakes simulate levels 0·2 to 2·5 m lower. Human adaptation to such changes is expensive. Warmer climates would decrease the spatial extent of ice cover on the Great Lakes; small lakes, especially to the south, would no longer freeze over every year. Temperature simulations for stratified lakes are 1-7°C warmer for surface waters, and 6°C cooler to 8°C warmer for deep waters. Thermocline depth would change (4 m shallower to 3·5 m deeper) with warmer climates alone; deepening owing to increases in light penetration would occur with reduced input of dissolved organic carbon (DOC) from dryer catchments. Dissolved oxygen would decrease below the thermocline. These physical changes would in turn affect the phytoplankton, zooplankton, benthos and fishes. Annual phytoplankton production may

  18. A SIMULATION STUDY ON THE SHRUNK WETLAND AROUND QINGHAI LAKE AND REGIONAL CLIMATE

    Institute of Scientific and Technical Information of China (English)

    WANG HanJie; JING Li; GAO YunXiao

    2005-01-01

    Because of the increasing concerns about global climate change, it has been known by more and more peoples that there is a close relationship between wetland and/or peatland resources and climate change. This paper presents a new methodology to study the local climate variation caused by wetland shrinking around Qinghai Lake, the largest in-land salty lake in China, by use of a regional climate model (RCM) that commonly used in climate change study. The objective focuses on the regional climate effect of the shrunk wetland coverage in recent years. The results of numerical experiment showed that if the wetland coverage around Qinhai Lake were recovered as if in early 50s of last century,the regional climate in this area could be better with more cloud covers, higher relative humidity and more precipitation. In the other word, the area of wetland reduced is one of the most important reasons that caused regional climate aridification,eco-environmental deterioration and even desertification around Qinhai Lake.

  19. Changes in the area of inland lakes in arid regions of central Asia during the past 30 years.

    Science.gov (United States)

    Bai, Jie; Chen, Xi; Li, Junli; Yang, Liao; Fang, Hui

    2011-07-01

    Inland lakes are major surface water resource in arid regions of Central Asia. The area changes in these lakes have been proved to be the results of regional climate changes and recent human activities. This study aimed at investigating the area variations of the nine major lakes in Central Asia over the last 30 years. Firstly, multi-temporal Landsat imagery in 1975, 1990, 1999, and 2007 were used to delineate lake extents automatically based on Normalized Difference Water Index (NDWI) threshold segmentation, then lake area variations were detailed in three decades and the mechanism of these changes was analyzed with meteorological data and hydrological data. The results indicated that the total surface areas of these nine lakes had decreased from 91,402.06 km(2) to 46,049.23 km(2) during 1975-2007, accounting for 49.62% of their original area of 1975. Tail-end lakes in flat areas had shrunk dramatically as they were induced by both climate changes and human impacts, while alpine lakes remained relatively stable due to the small precipitation variations. With different water usage of river outlets, the variations of open lakes were more flexible than those of other two types. According to comprehensive analyses, different types of inland lakes presented different trends of area changes under the background of global warming effects in Central Asia, which showed that the increased human activities had broken the balance of water cycles in this region.

  20. The water chemistry of some shallow lakes in Northern Patagonia and their nitrogen status in comparison with remote lakes in different regions of the globe

    Directory of Open Access Journals (Sweden)

    Rosario MOSELLO

    2008-08-01

    Full Text Available Eighteen small shallow lakes located in the Northern Patagonian Lake District, in southern South America, were sampled in 2001 and analysed for the main chemical variables (pH, conductivity, alkalinity, major ions and nutrients. The study lakes span a wide geographical and altitudinal range and belong partly to the Pacific and partly to the Atlantic watershed. The main aim of this study was to investigate the relationships between water chemistry and physical/geographical properties of these lakes. Secondly, the nitrogen content of the lakes was considered in detail, and results compared to those obtained in previous studies carried out in other remote areas of the globe (the Central Southern Alps in Italy, the Sierra da Estrela region in Portugal, the Svalbard Islands in the Arctic, the Khumbu-Himal region in Nepal, and the Terra Nova Bay area in Antarctica. In the Alps, lakes are characterised by markedly high nitrogen concentrations, manly as nitrate, due to the high inputs of nitrogen compounds from downwind sources like the Po Plain in Northern Italy. Conversely, lakes at remote locations such as the Andes, Antarctica and Himalaya are characterised by a low nitrogen content, mainly as organic nitrogen. This status is related to the limited atmospheric inputs of nitrogen affecting these regions.

  1. Chalcophile elements Hg, Cd, Pb, As in Lake Umbozero, Murmansk Region, Russia

    DEFF Research Database (Denmark)

    Dauvalter, V.A.; Kashulin, N.A.; Lehto, J.;

    2009-01-01

    to higher concentrations of heavy metals in upper layers of sediments as compared to deeper layers. Among heavy metals, the highest factors of contamination were found for Cd and Pb. Pollution of the lake by chalcophile elements has also resulted in their accumulation in organs and tissues of whitefish...... is affected by emissions and effluents from mining and metallurgical enterprises of the Murmansk Region, as well as air pollution of a global character. Surface and near-bottom maxima were found in the distributions of Pb and Cd in the water column. These two maxima appear to be associated with the cyclical...... growth of phytoplankton in surface water layers and with sedimentation of lifeless organisms and suspended particles in near-bottom layers. Average concentrations of Pb and Cd in the water column were more than the average value for water of lakes of the taiga zone. Pollution of Lake Umbozero led...

  2. Spatiotemporal trends of mercury in walleye and largemouth bass from the Laurentian Great Lakes region.

    Science.gov (United States)

    Monson, Bruce A; Staples, David F; Bhavsar, Satyendra P; Holsen, Thomas M; Schrank, Candy S; Moses, Sara K; McGoldrick, Daryl J; Backus, Sean M; Williams, Kathryn A

    2011-10-01

    The risk of mercury (Hg) exposure to humans and wildlife from fish consumption has driven extensive mercury analysis throughout the Great Lakes Region since the 1970s. This study compiled fish-Hg data from multiple sources in the region and assessed spatiotemporal trends of Hg concentrations in two representative top predator fish species. Walleye (Sander vitreus) and largemouth bass (Micropterus salmoides) were chosen for the trend analysis because they had more Hg records (63,872) than other fish species that had been sampled from waters throughout the region. Waterbody types were inland lakes (70%), the Great Lakes, impoundments, and rivers. The compiled datasets were analyzed with a mixed effects statistical model having random effects of station, year, and fish length; and fixed effects of year, tissue type, fish length, habitat, and season. The results showed a generally declining temporal trend in fish-Hg for the region (1970-2009), with spatial trends of increasing Hg concentration from south to north and from west to east across the region. Nonlinearity was evident in the general downward trends of Ontario walleye, with a shift to an upward trend beginning in the 1990s. Only ongoing monitoring can reveal if this upward shift is an oscillation in a long-term decline, a statistical anomaly, or a sustained declining temporal trend in regional fish-Hg concentrations.

  3. National hydroelectric power resources study. Preliminary inventory of hydropower resources. Volume 4. Lake Central region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-07-01

    The estimates of existing, incremental and the undeveloped hydropower potential for all states in the various regions of the country are presented. In the Lake Central region, the maximum physical potential for all sites exceeds 26,000 MW with an estimated average annual energy of more than 75,000 GWH. By comparison, these values represent about 5% of both the total potential capacity and hydroelectric energy estimated for the entire US. Of the total capacity estimated for the region, 2600 MW has been installed. The remainder (23,600 MW) is the maximum which could be developed by upgrading and expanding existing projects (15,800 MW), and by installing new hydroelectric power capacity at all potentially feasible, undeveloped sites (7800 MW). Small-scale facilities account for some 24% of the region's total installed capacity, but another 900 MW could be added to these and other small water-resource projects. In addition, 900 MW could be installed at potentially feasible, undeveloped small-scale sites. The small-scale resource varies considerably, with the states of Michigan and Wisconsin having the largest potential for incremental development at existing projects in the Lake Central region. This Lake Central region is composed of Minnesota, Wisconsin, Michigan, Ohio, Indiana, Illinois, Kentucky, Missouri, and Iowa.

  4. Bathymetric distribution of fish in the Apostle Islands region, Lake Superior

    Science.gov (United States)

    Dryer, William R.

    1966-01-01

    Records of seasonal and “all-season” (April-December) bathymetric distribution are given for 17 species of fish taken in bottom trawls and experimental gill nets fished on the bottom in 1958–63 in the Apostle Islands region of Lake Superior. The data are based on catches from 578 trawl tows at 2–59 fathoms and 301,900 linear feet of gill nets fished at 2–89 fathoms. Size of the fish varied widely among different species from the same gear and the same species from different gears. Seasonal differences in depth distribution were greatest for lake trout, bloaters, round whitefish, and older smelt, which exhibited an inshore movement in the summer and fall, and for longnose suckers, which migrated to deeper water with progress of the seasons. The all-season bathymetric distributions varied considerably among species. Round whitefish, 0- and I-group smelt, longnose suckers, ninespine sticklebacks, and johnny darters were most abundant at < 10 fathoms. Concentrations of lake trout, lake herring, lake whitefish, older smelt, trout-perch, and burbot were greatest at 10–29 fathoms. Pygmy whitefish were most common at 30–39 fathoms, bloaters and spoonhead sculpins at 40–49 fathoms, and shortjaw ciscoes, slimy sculpins, and fourhorn sculpins at 50–59 fathoms. The kiyi was most abundant at 70–79 fathoms.

  5. Probabilistic projections of regional climatic changes over the Great Lakes Basin

    Science.gov (United States)

    Wang, Xiuquan; Huang, Guohe; Baetz, Brian W.; Zhao, Shan

    2016-11-01

    As the largest surface fresh water system on earth, the Great Lakes is facing the threat of climate change. Understanding how the hydrologic cycle in the Great Lakes region would be affected by human-induced global warming is important for developing informed adaptation strategies. In this study, high-resolution regional climate ensemble simulations based upon the PRECIS modeling system are conducted to project future climatic changes over the Great Lakes Basin. The results show that the Great Lakes Basin is very likely to experience a continuous warming-up throughout the 21st century. Particularly, mean air temperatures will rise by 2.6 °C in the forthcoming decades (i.e., 2030s), 3.8 °C in the middle of the century (i.e., 2050s), and 5.6 °C to the end of the century (i.e., 2080s), respectively. The warming air temperatures are very likely to result in more precipitation over the entire basin. The annual total precipitation over the Great Lakes Basin is projected to increase by 8.9% in the 2030s and 12.2% in the 2050s, while the magnitude of precipitation increase would decline to 7.1% in the 2080s. The slow-down of the precipitation increase from the 2050s to the 2080s indicates a shift from the aggressive increase of precipitation before and in the middle of this century to the eventual decrease by the end of this century, suggesting that a nonlinear response relationship between precipitation and temperature may exist in the Great Lakes Basin and such a relationship is also likely to vary in response to global warming.

  6. Potential Economic Impacts from Offshore Wind in the Great Lakes Region (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, S.; Keyser, D.

    2014-01-01

    Offshore wind is a clean, renewable source of energy and can be an economic driver in the United States. To better understand the employment opportunities and other potential regional economic impacts from offshore wind development, the U.S. Department of Energy (DOE) funded research that focuses on four regions of the country. The studies use multiple scenarios with various local job and domestic manufacturing content assumptions. Each regional study uses the new offshore wind Jobs and Economic Development Impacts (JEDI) model, developed by DOE's National Renewable Energy Laboratory. This fact sheet summarizes the potential economic impacts identified by the study for the Great Lakes region.

  7. Grassland Degradation and Its Control in Region Around Qinghai Lake

    Institute of Scientific and Technical Information of China (English)

    JIANGJIANJUN; GongAIQI; 等

    1999-01-01

    A quite severe degradation was found in all seven types of grasslands in the study area involiving 12 counties of the northwestern Qinghai Province.The slightly,modeately and severely degraded grasslands occupied 49.7%,32.0%and 18.3% of the area respectively.The major factors resulting in the degradation were overgrazing,the damages from mice and grasshopper and blown sands,and improper use of grasslands,The measures to deal with these probles should be:1) to make livestock development in accordance with grassland carrying capacity for animals;2) to build more artificial grasslands with a stable and higher grass yield;3) to put more widely the rotation grazing system into practice;4) to clear up the poisonous grass species,and 5)to adopt more effective measures to deal with the damages to grasslands by mice and grasshoppers.

  8. Land use impacts on lake water quality in Alytus region (Lithuania)

    Science.gov (United States)

    Pereira, Paulo; Laukonis, Rymvidas

    2016-04-01

    Land use has important impacts on soils, surface and ground water quality. Urban agricultural areas are an important source of pollutants, which can reach lakes through surface runoff and underground circulation. Human intervention in the landscape is one of the major causes pollution and land degradation, thus it is very important to understand the impacts of and use on environment and if they have some spatial pattern (Pereira et al., 2013, 2015; Brevik et al., 2016). The identification of the spatial pattern of lakes pollution is in Alytus area (Lithuania) is fundamental, since they provide an important range of ecosystem services to local communities, including food and recreational activities. Thus, the degradation of these environments can induce important economic losses. In this context, it is import to identify the areas with high pollutant accumulation and the environmental and human factors responsible for it. The objective of this work is to study identify the amount of some important nutrients resultant from human activities in lake water quality in Alytus region (Lithuania). Alytus region is located in southern part of Lithuania and has an approximate area of 40 km2. Inside this region we analyzed several water quality parameters of 55 lakes, including, pH, electrical conductivity (EC), suspended materials (SM), water clarity (WC) biochemical oxygen demand (BDO), total phosphorous (TP), total Nitrogen (TN), dissolved organic carbon (DOC), as other environmental variables as altitude, lake maximum deep (MD), lake area and land use according Corine land cover classification (CLC2006). Previous to data analysis, data normality and homogeneity of the variances, was assessed with the Shapiro-wilk and Leven's test, respectively. The majority of the data did not respect the Gaussian distribution and the heteroscedasticity, even after a logarithmic, and box-cox transformation. Thus, in this work we used the logarithmic transformed data to do a principal

  9. Lake Morphometry for NHD Lakes in the Northern Portion of the South Atlantic-Gulf Region 3 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  10. Lake Morphometry for NHD Lakes in the Southern Portion of the South Atlantic-Gulf Region 3 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  11. Lake Morphometry for NHD Lakes in the Western Portion of the South Atlantic-Gulf Region 3 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  12. Cattle, identity and genocide in the African Great Lakes region

    Directory of Open Access Journals (Sweden)

    Andrew Reid

    2000-11-01

    Full Text Available Archaeological research into the origins of the cattle-keeping people of southwestern Uganda has overturned long-held beliefs about the separate origins of the pastoral and agricultural populations of the region. Study of indigenous political development and nineteenth-century colonialism shows that the present-day ethnic identities, which fuelled the genocide in Rwanda in 1994, are recent constructions.

  13. A new biogeochemical model to simulate regional scale carbon emission from lakes, ponds and wetlands

    Science.gov (United States)

    Bayer, Tina; Brakebusch, Matthias; Gustafsson, Erik; Beer, Christian

    2016-04-01

    Small aquatic systems are receiving increasing attention for their role in global carbon cycling. For instance, lakes and ponds in permafrost are net emitters of carbon to the atmosphere, and their capacity to process and emit carbon is significant on a landscape scale, with a global flux of 8-103 Tg methane per year which amounts to 5%-30% of all natural methane emissions (Bastviken et al 2011). However, due to the spatial and temporal highly localised character of freshwater methane emissions, fluxes remain poorly qualified and are difficult to upscale based on field data alone. While many models exist to model carbon cycling in individual lakes and ponds, we perceived a lack of models that can work on a larger scale, over a range of latitudes, and simulate regional carbon emission from a large number of lakes, ponds and wetlands. Therefore our objective was to develop a model that can simulate carbon dioxide and methane emission from freshwaters on a regional scale. Our resulting model provides an additional tool to assess current aquatic carbon emissions as well as project future responses to changes in climatic drivers. To this effect, we have combined an existing large-scale hydrological model (the Variable Infiltration Capacity Macroscale Hydrologic Model (VIC), Liang & Lettenmaier 1994), an aquatic biogeochemical model (BALTSEM, Savchuk et al., 2012; Gustafsson et al., 2014) and developed a new methane module for lakes. The resulting new process-based biogeochemical model is designed to model aquatic carbon emission on a regional scale, and to perform well in high-latitude environments. Our model includes carbon, oxygen and nutrient cycling in lake water and sediments, primary production and methanogenesis. Results of calibration and validation of the model in two catchments (Torne-Kalix in Northern Sweden and of a large arctic river catchment) will be presented.

  14. An inventory of glacial lakes in the Third Pole region and their changes in response to global warming

    Science.gov (United States)

    Dai, Y.; Zhang, G.; Yao, T.; Xie, H.

    2015-12-01

    No glacial lake census exists for the Third Pole region, which includes the Pamir-Hindu Kush-Karakoram-Himalayas and the Tibetan Plateau. Therefore, comprehensive information is lacking about the distribution of and changes in glacial lakes caused by current global warming conditions. In this study, the first glacial lake inventories for the Third Pole were conducted for ~1990, 2000, and 2010 using Landsat TM/ETM+ data. Glacial lake spatial distributions, corresponding areas and temporal changes were examined. The significant results are as follows. (1) There were 4602, 4981, and 5701 glacial lakes (> 0.003 km2) covering areas of 553.9 ± 90, 581.2 ± 97, and 682.4 ± 110 km2 in ~1990, 2000, and 2010, respectively; these lakes are primarily located in the Brahmaputra (39%), Indus (28%), and Amu Darya (10%) basins. (2) Small lakes (Lakes closer to glaciers and at higher altitudes, particularly those connected to glacier termini, have undergone larger area changes. (4) Glacier-fed lakes are dominant in both quantity and area (> 70%) and exhibit faster expansion trends overall compared to non-glacier-fed lakes. We conclude that glacier meltwater may play a dominant role in the areal expansion of most glacial lakes in the Third Pole. In addition, the patterns of the glacier-fed lakes correspond well with warming temperature trends and negative glacier mass balance patterns. This paper presents an important database of glacial lakes and provides a basis for long-term monitoring and evaluation of outburst flood disasters primarily caused by glacial lakes in the Third Pole.

  15. Clear retainer

    Directory of Open Access Journals (Sweden)

    Priyakorn Chaimongkol

    2017-01-01

    Full Text Available A clear retainer is a removable retainer that is popular in the present day. Compared with conventional fixed and removable orthodontic retainers, it is a more esthetic, comfortable, and inexpensive appliance. Although several studies have been published about clear retainers, it could be difficult to interpret the results because of the variety of study designs, sample sizes, and research methods. This article is intended to compile the content from previous studies and discuss advantages, disadvantages, fabrication, insertion, and adjustment. Moreover, the effectiveness in maintaining dental position, occlusion, retention protocols, thickness, and survival rate of clear retainers is discussed.

  16. Great Lakes O shore Wind Project: Utility and Regional Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Sajadi, Amirhossein [Case Western Reserve Univ., Cleveland, OH (United States); Loparo, Kenneth A. [Case Western Reserve Univ., Cleveland, OH (United States); D' Aquila, Robert [General Electric (GE), Albany, NY (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); Waligorski, Joseph G. [FirstEnergy, Akron, OH (United States); Baker, Scott [PJM Interconnection, Audubon, PA (United States)

    2016-06-30

    This project aims to identify transmission system upgrades needed to facilitate offshore wind projects as well as operational impacts of offshore generation on operation of the regional transmission system in the Great Lakes region. A simulation model of the US Eastern Interconnection was used as the test system as a case study for investigating the impact of the integration of a 1000MW offshore wind farm operating in Lake Erie into FirstEnergy/PJM service territory. The findings of this research provide recommendations on offshore wind integration scenarios, the locations of points of interconnection, wind profile modeling and simulation, and computational methods to quantify performance, along with operating changes and equipment upgrades needed to mitigate system performance issues introduced by an offshore wind project.

  17. A preliminary knowledge-driven prediction model of snail distribution in the Poyang Lake region

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Present monitoring and prediction of schistosomiasis's intermediate parasite,snail,are based on remote sensing image's spectral signatures,and the calculation result iS in fact an incomplete-constraints solution.TM image of the Poyang Lake region on October 31,2005 was combined with GIS thematic data(DEM,boundary of the Poyang Lake,vegetation,soil and land use)to make a prediction on snail spatial distribution in the region by remote sensing,geo-informatics and knowledge-driven modeling according to mechanism of snail occurrence.Result shows that with change of overall fuzzy membership of snail occurrence from high to low,snail occurrence of the snail samples of validation group goes up to 81% within 10% high fuzzy membership range,denoting high efficiency of the model in predicting snail occurrence.

  18. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries.

    Science.gov (United States)

    Thevenon, Florian; Graham, Neil D; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

    2011-12-15

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (>100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents.

  19. SNOW CLEARING

    CERN Multimedia

    Groupe de Transport/Transport Group

    1999-01-01

    In order to facilitate snow-clearing operations, which commence at 4.30 every morning, drivers of CERN vehicles are kindly requested to group their cars together in the car parks. This will greatly help us in our work. Thank you for your co-operation.Transport Group / ST-HMTel. 72202

  20. Coral Research Data from NOAA's Undersea Research Center, North Atlantic and Great Lakes Region, NOAA's Undersea Research Program (NURP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's Undersea Research Center for the NOAA's Undersea Research Center for the North Atlantic and Great Lakes region (NAGL) explores and studies the waters off the...

  1. Sources and fate of terrestrial dissolved organic carbon in lakes of a Boreal Plains region recently affected by wildfire

    Directory of Open Access Journals (Sweden)

    D. Olefeldt

    2013-04-01

    Full Text Available Downstream mineralization and sedimentation of terrestrial dissolved organic carbon (DOC render lakes important for landscape carbon cycling in the boreal region, with regulating processes potentially sensitive to perturbations associated with climate change including increased occurrence of wildfire. In this study we assessed chemical composition and reactivity (during both dark and UV incubations of DOC from lakes and terrestrial sources within a peatland-rich western boreal plains region partially affected by a recent wildfire. While wildfire was found to increase aromaticity of DOC in peat pore-water above the water table, it had no effect on concentrations or composition of DOC from peatland wells and neither affected mineral well or lake DOC characteristics. Lake DOC composition reflected a mixing of peatland and mineral groundwater, with a greater influence of mineral sources to lakes in coarse- than fine-textured settings. Peatland DOC was less biodegradable than mineral DOC, but both mineralization and sedimentation of peatland DOC increased substantially during UV incubations through selective removal of aromatic humic and fulvic acids. DOC composition in lakes with longer residence times had characteristics consistent with increased UV-mediated processing. We estimate that about half of terrestrial DOC inputs had been lost within lakes, mostly due to UV-mediated processes. The importance of within-lake losses of aromatic DOC from peatland sources through UV-mediated processes indicate that terrestrial-aquatic C linkages in the study region are largely disconnected from recent terrestrial primary productivity. Together, our results suggest that characteristics of the study region (climate, surface geology and lake morphometry render linkages between terrestrial and aquatic C cycling insensitive to the effects of wildfire by determining dominant terrestrial sources and within-lake processes of DOC removal.

  2. A fugacity model for source determination of the Lake Baikal region pollution with polychlorinated Biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Sofiev, M. [Finnish Meteorological Inst., Helsinki (Finland); Galperin, M.; Maslyaev, A. [Inst. of Program Systems, Pereslavl-Zalesskiy (Russian Federation); McLachlan, M. [Stockholm Univ. (Sweden); Wania, F. [Toronto Univ. (Canada)

    2004-09-15

    PCBs were discovered in the Lake Baikal ecosystem by Malakhov et al. and Bobovnikova et al. A follow up to the initial study showed no decrease over 1981-1989 4, in contrast to what has been observed in other water bodies in the industrialised world. Further studies also showed the contamination in pinnipeds to be among the highest measured anywhere. Above studies and other data suggested a presence of a strong local PCB source (or several ones), which has had a widespread adverse effect for the whole region. To locate the source, Mamontov et al. collected samples from 34 sites over the region, the analysis of which showed a gradient of a factor of 1000, with the lowest concentrations at the north-east of Lake Baikal and the highest concentrations close to the city of Usolye Sibirskoye, a centre of the chemical industry in the Angara River valley. A continuous decrease in the soil contamination was observed along the path from Usolye Sibirskoye up the Angara River valley to Lake Baikal and from there north-eastward along the lake. These results indicate that there was (and perhaps still is) a major source of PCBs in the Usolye area, from where the PCBs are dispersed over the region. However, various obstacles prevent direct observations of potential sources. Therefore, a mathematical modelling approach was adopted in a currently ongoing INTAS project aiming to shed some more light on this problem. The model principles, setup and the results of the first experiments are presented in the current paper.

  3. Climate Change in Africa: Impacts and Effects on the Inhabitants of the Lake Chad Region.

    Science.gov (United States)

    Abubakar, B.; Tahir, S. M.; Olisa, O.

    2009-05-01

    The Department of Energy and Climate Change defined climate as the average weather experienced over a long period. This includes temperature, wind and rainfall patterns. The climate of the Earth is not static, and has changed many times in response to a variety of natural causes. Due to human activities in emmiting green house gases has resulted the Earth to get warmed by 0.74°C over the last hundred years. Around 0.4°C of this warming has occurred since the 1970s. Climate is now one of the major phenomenon threatening lives and humanity in general since the beginning of industrial revolution. Climate exerts a profound influence on the lives of poor populations in the Lake Chad region of Africa who depend on fishing and crop cultivation for livelihood and sustenance, who are unprotected against climate-related diseases, who lacked secure access to water and food and who are vulnerable to hydro meteorological hazard. The effects of climate change on the study area are many and include diminishing resources and conflicts over the available limited water resources. The Lake Chad region is a fragile area with high climate variability and extremes of weather. As this inland water is used for domestic and agricultural purposes, salt mining, as well as transportation by Nigerians, Nigeriens, Chadian and Cameroonians, it is an area of trans-boundary water conflicts. This paper examines the part played by climate change in the decline of fishery resources and livelihood activities in the Lake Chad region. Data from field studies, structured interview and secondary sources show that fish catches and livelihood activities have declined tremendously in recent times due to several factors including overexploitation and increasing demands on the aquatic resources. Findings from the study show that droughty periods have resulted in the reduction of open lake water surface from about 25,000 km2 in 1973 to less than 2,000 km2 in the 1990s. This has led to the diminishing aquatic

  4. Use of Satellite and In Situ Reflectance Data for Lake Water Color Characterization in the Everest Himalayan Region

    Directory of Open Access Journals (Sweden)

    Erica Matta

    2017-02-01

    Full Text Available This study applied remote sensing techniques to the study of water color in Himalayan glacial lakes as a proxy of suspended solid load. In situ measurements gathered in 5 lakes in October 2014 during satellite data acquisition enabled the characterization of water reflectance and clarity and supported image processing. Field data analysis led to a distinction between 3 water colors and a consequent lake water color classification on a regional scale from Landsat-8 data previously corrected for atmospheric and adjacency effects. Several morphometric parameters (lake size and shape, distance between lake and glacier were also computed for the lakes thus classified. The results showed spatial and temporal variations in lake water color, suggestive of relationships between glacier shrinkage and the presence of brighter and more turbid water. A finer-scale analysis of the spatial variability of water reflectance on Chola Lake (based on GeoEye-1 data captured on 18 October 2014 showed the contribution of water component absorption from the inflow. Overall, the findings support further research to monitor Himalayan lakes using both Landsat-8 and Sentinel-2 (with its improved resolutions.

  5. A needs assessment for climate change education in the Great Lakes region

    Science.gov (United States)

    Rutherford, S.; Schneider, L. B.; Walters, H.

    2011-12-01

    The National Science Foundation funded Great Lakes Climate Change Science and Education Systemic Network project is implementing a two year planning effort to create innovative education programs to benefit the public, formal and informal educators, scientists, and journalists in the region. The current partners include Eastern Michigan University, NOAA's Great Lakes Environmental Research Lab, University of Michigan, Michigan State University, Knight Center for Environmental Journalism, Ashland University, Ann Arbor Hands-On Museum, and the College of Exploration. To create a network we are planning to bring together different stakeholders to write two white papers, one from the scientists' perspective and the other from the educators'(both formal and informal) perspective. The current partners' key personnel have produced a list of possible people/institutions to include in a stakeholder survey. Some of the key personnel developed their databases from scratch. Some used listserves, and others tried a snowball email. To identify the best strategy that will inform these various stakeholders and the public regarding the science of climate change in the Great Lakes Region, a survey was developed for each of the different stakeholders. The survey is divided into three parts: 1) questions which convey some understanding of climate science and climate change 2) demographic questions, and finally 3) questions that pertain to the professional concerns or perspectives of the various stakeholders. This survey is being used to provide the project team with a "needs assessment" from the interested members of those stakeholders. The results from this process will be summarized.

  6. Unplanned roads impacts assessment in Phewa Lake watershed, Western region, Nepal

    Science.gov (United States)

    Leibundgut, Geoffroy; Sudmeier-Rieux, Karen; Devkota, Sanjaya; Jaboyedoff, Michel; Penna, Ivanna; Adhikari, Anu; Khanal, Rajendra

    2015-04-01

    This work describes current research being conducted in the Phewa Lake watershed, near Pokhara in Nepal's Siwaliks/Middle hills, a moist sub-tropical zone with the highest amount of annual rainfall in Nepal (4,500 - 5,000 mm). The watershed lithology is mainly siltstone, sandstones and intensively weathered rocks, highly prone to erosion and shallow landslides (Agrawala et al., 2003). The main purpose of this study is to focus on the impact of unplanned earthen road construction in the Phewa Lake watershed as part of land use changes over 30 years in one of Nepal's most touristic regions. Over the past three decades, the road network has expanded exponentially and a majority of rural earthen roads are often funded by communities themselves, with some government subsidies. They are usually constructed using a local bulldozer contractor with no technical or geological expertise increasing erosion processes, slope instabilities risk and impacts to settlements, forests, water sources, agriculture lands, and infrastructure. Moreover, these human-induced phenomena are being compounded by increasingly intense monsoon rains, likely due to climate change (Petley, 2010). Research methods were interdisciplinary and based on a combination of remote sensing, field observations and discussions with community members. The study compared 30 year-old aerial photos with current high resolution satellite images to correlate changes in land use with erosion and slope instabilities. Secondly, most of the watershed's roads were surveyed in order to inventory and quantify slope instabilities and soil loss events. Using a failure-characteristics grid, their main features were measured (location, size, type and extension of damage areas, etc.) and a GIS data base was created. We then estimated economic impacts of these events in terms of agriculture lands losses and road maintenance, based on field observations and discussions with affected people. Field work investigations have shown that

  7. Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

    Science.gov (United States)

    Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

    2010-01-01

    A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow

  8. Asynchrony in the inter-annual recruitment of lake whitefish Coregonus clupeaformis in the Great Lakes region

    Science.gov (United States)

    Zischke, Mitchell K.; Bunnell, David; Troy, Cary D.; Berglund, Eric K.; Caroffino, David C.; Ebener, Mark P.; He, Ji X.; Sitar, Shawn P.; Hook, Tomas O.

    2017-01-01

    Spatially separated fish populations may display synchrony in annual recruitment if the factors that drive recruitment success, particularly abiotic factors such as temperature, are synchronised across broad spatial scales. We examined inter-annual variation in recruitment among lake whitefish (Coregonus clupeaformis) populations in lakes Huron, Michigan and Superior using fishery-dependent and -independent data from 1971 to 2014. Relative year-class strength (RYCS) was calculated from catch-curve residuals for each year class across multiple sampling years. Pairwise comparison of RYCS among datasets revealed no significant associations either within or between lakes, suggesting that recruitment of lake whitefish is spatially asynchronous. There was no consistent correlation between pairwise agreement and the distance between datasets, and models to estimate the spatial scale of recruitment synchrony did not fit well to these data. This suggests that inter-annual recruitment variation of lake whitefish is asynchronous across broad spatial scales in the Great Lakes. While our method primarily evaluated year-to-year recruitment variation, it is plausible that recruitment of lake whitefish varies at coarser temporal scales (e.g. decadal). Nonetheless, our findings differ from research on some other Coregonus species and suggest that local biotic or density-dependent factors may contribute strongly to lake whitefish recruitment rather than inter-annual variability in broad-scale abiotic factors.

  9. Uncertainty in the Himalayan energy-water nexus: estimating regional exposure to glacial lake outburst floods

    Science.gov (United States)

    Schwanghart, Wolfgang; Worni, Raphael; Huggel, Christian; Stoffel, Markus; Korup, Oliver

    2016-07-01

    Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia’s soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.

  10. Imagining the Great Lakes Region: discourses and practices of civil society regional approaches for peacebuilding in Rwanda, Burundi and DR Congo

    NARCIS (Netherlands)

    Leeuwen, van M.

    2008-01-01

    The idea has gained ground in recent years that, as conflicts in the countries of the Great Lakes Region are strongly interlinked, regional approaches are necessary to resolve them. This interest in regional dimensions of conflict and peacebuilding also gains currency in other parts of the world. At

  11. A Study of the Atmospheric Boundary Layer Structure During a Clear Day in the Arid Region of Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang; WANG Sheng

    2009-01-01

    The local climate and atmospheric circulation pattern exert a clear influence on the atmospheric boundary layer (ABL) formation and development in Northwest China. In this paper, we use field observational data to analyze the distribution and characteristics of the ABL in the extremely arid desert in Dunhuang, Northwest China. These data show that the daytime convective boundary layer and night time stable boundary layer in this area extend to higher altitudes than in other areas. In the night time, the stable boundary layer exceeds 900 m in altitude and can sometimes peak at 1750 m, above which the residual layer may reach up to about 4000 m. The daytime convective boundary layer develops rapidly after entering the residual layer, and exceeds 4000 m in thickness. The results show that the deep convective boundary layer in the daytime is a pre-requisite for maintaining the deep residual mixed layer in the night time. Meanwhile, the deep residual mixed layer in the night time provides favorable thermal conditions for the development of the convective boundary layer in the daytime. The prolonged periods of clear weather that often occurs in this area allow the cumulative effect of the atmospheric residual layer to develop fully, which creates thermal conditions beneficial for the growth of the daytime convective boundary layer. At the same time, the land surface process and atmospheric motion within the surface layer in this area also provide helpful support for forming the particular structure of the thermal ABL. High surface temperature is clearly the powerful external thermal forcing for the deep convective boundary layer. Strong sensible heat flux in the surface layer provides the required energy. Highly convective atmosphere and strong turbulence provide the necessary dynamic conditions, and the accumulative effect of the residual layer provides a favorable thermal environment.

  12. Diurnal variability of regional cloud and clear-sky radiative parameters derived from GOES data. I - Analysis method. II - November 1978 cloud distributions. III - November 1978 radiative parameters

    Science.gov (United States)

    Minnis, P.; Harrison, E. F.

    1984-01-01

    Cloud cover is one of the most important variables affecting the earth radiation budget (ERB) and, ultimately, the global climate. The present investigation is concerned with several aspects of the effects of extended cloudiness, taking into account hourly visible and infrared data from the Geostationary Operational Environmental Satelite (GOES). A methodology called the hybrid bispectral threshold method is developed to extract regional cloud amounts at three levels in the atmosphere, effective cloud-top temperatures, clear-sky temperature and cloud and clear-sky visible reflectance characteristics from GOES data. The diurnal variations are examined in low, middle, high, and total cloudiness determined with this methodology for November 1978. The bulk, broadband radiative properties of the resultant cloud and clear-sky data are estimated to determine the possible effect of the diurnal variability of regional cloudiness on the interpretation of ERB measurements.

  13. Assessment of Nitrogen Pollutant Sources in Surface Waters of Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    XIE Ying-Xin; XIONG Zheng-Qin; XING Guang-Xi; SUN Guo-Qing; ZHU Zhao-Liang

    2007-01-01

    The nitrogen(N)pollution status of the 12 most important rivers in Changshu,Taihu Lake region was investigated.Water samples were collected from depths of 0.5-1.0 m with the aid of the global positioning system (GPS).The seasonal variations in the concentrations of different N components in the rivers were measured.Using tension-free monolith lysimeters and 15 N-labeled fertilizer,field experiments were carried out in this region to determine variations of 15Nabundance of NO-3 in the leachate during the rice and wheat growing seasons,respectively.Results showed that the main source of N pollution of surface waters in the Taihu Lake region was not the N fertilizer applied in the farmland but the urban domestic sewage and rural human and animal excreta directly discharged into the water bodies without treatment.Atmospheric dry and wet N deposition was another evident source of N pollutant of the surface waters.In conclusion.it would not be correct to attribute the N applied to farmlands as the source of N pollution of the surface waters in this region.

  14. Atmospheric processes of organic pollutants over a remote lake on the central Tibetan Plateau: implications for regional cycling

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Yao, Tandong

    2017-01-01

    Atmospheric processes (air-surface exchange, and atmospheric deposition and degradation) are crucial for understanding the global cycling and fate of organic pollutants (OPs). However, such assessments over the Tibetan Plateau (TP) remain uncertain. More than 50 % of Chinese lakes are located on the TP, which exerts a remarkable influence on the regional water, energy, and chemical cycling. In this study, air and water samples were simultaneously collected in Nam Co, a large lake on the TP, to test whether the lake is a secondary source or sink of OPs. Lower concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were observed in the atmosphere and lake water of Nam Co, while the levels of polycyclic aromatic hydrocarbons (PAHs) were relatively higher. Results of fugacity ratios and chiral signatures both suggest that the lake acted as the net sink of atmospheric hexachlorocyclohexanes (HCHs), following their long-range transport driven by the Indian monsoon. Different behaviours were observed in the PAHs, which primarily originated from local biomass burning. Acenaphthylene, acenaphthene, and fluorene showed volatilization from the lake to the atmosphere, while other PAHs were deposited into the lake due to the integrated deposition process (wet/dry and air-water gas deposition) and limited atmospheric degradation. As the dominant PAH compound, phenanthrene exhibited a seasonal reversal of air-water gas exchange, which was likely related to the melting of the lake ice in May. The annual input of HCHs from the air to the entire lake area (2015 km2) was estimated as 1.9 kg yr-1, while input estimated for ∑ 15PAHs can potentially reach up to 550 kg yr-1. This study highlights the significance of PAH deposition on the regional carbon cycling in the oligotrophic lakes of the TP.

  15. Regional-scale analysis of lake outburst hazards in the southwestern Pamir, Tajikistan, based on remote sensing and GIS

    Directory of Open Access Journals (Sweden)

    M. Mergili

    2011-05-01

    Full Text Available This paper presents an analysis of the hazards emanating from the sudden drainage of alpine lakes in South-Western Tajik Pamir. In the last 40 yr, several new lakes have formed in the front of retreating glacier tongues, and existing lakes have grown. Other lakes are dammed by landslide deposits or older moraines. In 2002, sudden drainage of a glacial lake in the area triggered a catastrophic debris flow. Building on existing approaches, a rating scheme was devised allowing quick, regional-scale identification of potentially hazardous lakes and possible impact areas. This approach relies on GIS, remote sensing and empirical modelling, largely based on medium-resolution international datasets. Out of the 428 lakes mapped in the area, 6 were rated very hazardous and 34 hazardous. This classification was used for the selection of lakes requiring in-depth investigation. Selected cases are presented and discussed in order to understand the potentials and limitations of the approach used. Such an understanding is essential for the appropriate application of the methodology for risk mitigation purposes.

  16. Environmental change within the Balkan region during the past ca. 50 ka recorded in the sediments from lakes Prespa and Ohrid

    Directory of Open Access Journals (Sweden)

    B. Wagner

    2010-10-01

    Full Text Available Lakes Prespa and Ohrid, in the Balkan region, are considered to be amongst the oldest lakes in Europe. Both lakes are hydraulically connected via karst aquifers. From Lake Ohrid, several sediment cores up to 15 m long have been studied over the last few years. Here, we document the first long sediment record from nearby Lake Prespa to clarify the influence of Lake Prespa on Lake Ohrid and the environmental history of the region. Radiocarbon dating and dated tephra layers provide robust age control and indicate that the 10.5 m long sediment record from Lake Prespa reaches back to 48 ka. Glacial sedimentation is characterized by low organic matter content and absence of carbonates in the sediments, which indicate oligotrophic conditions in both lakes. Holocene sedimentation is characterized by particularly high carbonate content in Lake Ohrid and by particularly high organic matter content in Lake Prespa, which indicates a shift towards more mesotrophic conditions in the latter. Long-term environmental change and short-term events, such as related to the Heinrich events during the Pleistocene or the 8.2 ka cooling event during the Holocene, are well recorded in both lakes, but are only evident in certain proxies. The comparison of the sediment cores from both lakes indicates that environmental change affects particularly the trophic state of Lake Prespa due to its lower volume and water depth.

  17. Occurrence of 102 cases of paracoccidioidomycosis in 18 months in the Itaipu Lake region, Western Paraná

    Directory of Open Access Journals (Sweden)

    Eduardo Alexandre Loth

    2011-10-01

    Full Text Available INTRODUCTION: The study investigated the incidence of disease and death events among patients with paracoccidioidomycosis who were residents in the Itaipu Lake region from 2008 to 2009. METHODS: A review of patient records was conducted at the Department of Tuberculosis of the Epidemiology Center of the City of Foz do Iguaçu, Paraná. RESULTS: The results identified 102 new cases of paracoccidioidomycosis in the period described, 72 men and 30 women, and 15 deaths were recorded during the study. CONCLUSIONS: It can be concluded that the Itaipu Lake region is an endemic region.

  18. Housing Archetype Analysis for Home Energy-Efficient Retrofit in the Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. -K. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Mrozowski, T. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Harrell-Seyburn, A. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Ehrlich, N. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Hembroff, L. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Lieburn, B. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Mazor, M. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); McIntyre, A. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Mutton, C. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Parsons, G. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Syal, M. G. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States); Wilkinson, R. [Cost Effective Energy Retrofit (CEER) Team, Midland, MI (United States)

    2014-09-01

    This project report details activities and results of the "Market Characterization" project undertaken by the Cost Effective Energy Retrofit (CEER) team targeted toward the DOE goal of achieving 30%-50% reduction in existing building energy use. CEER consists of members from the Dow Chemical Company, Michigan State University, Ferris State University, and Habitat for Humanity Kent County. The purpose of this market characterization project was to identify housing archetypes which are dominant within the Great Lakes region and therefore offer significant potential for energy-efficient retrofit research and implementation due to the substantial number of homes possessing similar characteristics. Understanding the characteristics of housing groups referred to as "archetypes" by vintage, style, and construction characteristics can allow research teams to focus their retrofit research and develop prescriptive solutions for those structure types which are prevalent and offer high potential uptake within a region or market.

  19. Regional maximum rainfall analysis using L-moments at the Titicaca Lake drainage, Peru

    Science.gov (United States)

    Fernández-Palomino, Carlos Antonio; Lavado-Casimiro, Waldo Sven

    2016-07-01

    The present study investigates the application of the index flood L-moments-based regional frequency analysis procedure (RFA-LM) to the annual maximum 24-h rainfall (AM) of 33 rainfall gauge stations (RGs) to estimate rainfall quantiles at the Titicaca Lake drainage (TL). The study region was chosen because it is characterised by common floods that affect agricultural production and infrastructure. First, detailed quality analyses and verification of the RFA-LM assumptions were conducted. For this purpose, different tests for outlier verification, homogeneity, stationarity, and serial independence were employed. Then, the application of RFA-LM procedure allowed us to consider the TL as a single, hydrologically homogeneous region, in terms of its maximum rainfall frequency. That is, this region can be modelled by a generalised normal (GNO) distribution, chosen according to the Z test for goodness-of-fit, L-moments (LM) ratio diagram, and an additional evaluation of the precision of the regional growth curve. Due to the low density of RG in the TL, it was important to produce maps of the AM design quantiles estimated using RFA-LM. Therefore, the ordinary Kriging interpolation (OK) technique was used. These maps will be a useful tool for determining the different AM quantiles at any point of interest for hydrologists in the region.

  20. Depositional Characteristics of Lake-Floor Fan of Cretaceous Lower Yaojia Formation in Western Part of Central Depression Region,Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    Xin Renchen; Li Guifan; Feng Zhiqiang; Liang Jiangping; Lin Changsong

    2009-01-01

    Based on the integrated subsurface data,including those of over 600 m drilled cores,more than 30 drilled wells and 600 km2 three-dimensional (3D) seismic-reflection data of the study area, the characteristics of the lake-floor fan of lower Yaojia(姚家) Formation have been clarified.An evident lacustrine slope break and a steep slope belt developed in the west of Songliao(松辽)basin during depositional period of Qingshankou(青山口)-Yaojia formations(K2).The slope gradient was about 15 m/km.During the depositional period of lower Yaojia Formation,the lake shrank and the shore line of the western Songliao basin shifted to the lacustrine slope-break.The wedge-shaped sediment body,which is interpreted as the lowstand system tract of SQy1 (LSTy1),developed in the area below the slope-break.The LSTyl is pinched out in the west of the study area.As to the thickness of LSTyl,ft is thicker in the east with SO m in its thickness than in the west The LSTyl,rich in sandstone,can be divided into lower part LSTylL and upper part LSTy1u based on two onlap seismic reflection phases,and core and logging data clearly.The various sediments' gravity flow deposits developed and the complex of lake-floor fan formed in the LSTyl under the slope-break in the western part of the central depression region.The lake-floor fan consists of various sediments' gravity flow deposits,including: (1) turbidity deposits with characteristics of Bouma sequences; (2) sand-bearing muddy debrite dominated by mud and mixed by sand; (3) mud-bearing sandy debrites characterized by dominated sand and mixed by mud; (4) sandy debris laminar flow deposits with massive or inclined bedding,and (5) sandy slump deposits developed as deforma tional sedimentary structure.During the lower lake-level period (LSTy1L),the western clinoform region was erosion or sediment pass-by area; the terrigenous clastic was directly transported to deep-water area,converted to channelized sandy debris flow,and combined with slump

  1. Maintaining a clear line of sight through regional climate change analysis: the importance of distinguishing knowledge and data

    Science.gov (United States)

    Whetton, P.

    2014-12-01

    Developing, or choosing, appropriate climate projections for use in a particular context is challenging. To help with this, it is useful to distinguish between two types of climate projection information. First there is scientific knowledge about the range of plausible climate change. Such knowledge can synthesise a range of relevant evidence, may convey messages in qualitative terms only, and may also have attached confidence (e.g. as in IPCC assessments).This knowledge can be used in context setting but may also be sufficient information for qualitative impact applications aimed at narrative development. Secondly, there are projection data sets tailored for use in technical risk assessments. Although these two products draw on similar source material (primarily global and regional climate model output), the information they can contain about future climate can be quite different. Often in meeting user needs, only a subset of the range of plausible future climate is considered in application-ready products. This may be due to user needs for downscaled information which comes from limited models, or their need to work with a small number of multivariate scenarios which are best provided by the outputs of single climate models. In the push to create sophisticated datasets that meet demanding technical needs, the larger perspective of representativeness can go by the wayside, and there is a risk that data users will tacitly believe their data are representative of future change when in fact they may not be. Thus a key challenge for risk assessment is for projection providers and users to work in unison to ensure that the two aspects of knowledge and data are as harmonised as possible. These concepts will be illustrated using projection products from the Australian context, including a range of new national climate projection products developed recently to support applications in natural resources management planning.

  2. [Land Use Pattern Change and Regional Sustainability Evaluation of Wetland in Jiaogang Lake].

    Science.gov (United States)

    Yang, Yang; Cai, Yi-min; Bai, Yan-ying; Chen, Wei-ping; Yang, Xiu-chao

    2015-06-01

    Changes in land use and sustainability evaluation of wetland in Jiaogang Lake from 1995 to 2013 were analyzed, based on the land use change models and an index system, supported by RS, GIS, and social statistical data. The results showed: (1) dry land, paddy field, and building land were the predominant landscape in the study area. The arable land was mainly converted during 1995-2000, which was driven by the extension of agriculture, and the building land increased significantly during 2010-2013, which was driven by the tourism development. (2) Compared to the beginning research area, the building land increased by 123.3%, and the wetland decreased by 23.15%. The land system was at risk for a low proportion of wetland, scarcity of unused land, and the fragmented landscape. (3) The regional sustainability results were bad level, bad level, poor level, good level, and poor level during the different periods, with some room for improvement. (4) The fitness of regional sustainability in study area yielded satisfactory results in 2010, owing to the rapid growth of regional productivity and the regional stability. Since 2010, with the increasing environmental load, the regional sustainability fell down to the poor level. The obstruction of sustainable development is necessary to be addressed in the study area.

  3. Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Zheng; Luo, Qi-Zhi; Lin, Lin [Department of Immunology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China); Su, Yu-Ping; Peng, Hai-Bo [Central Blood Bank in Yueyang, Yueyang, Hunan Province (China); Du, Kun; Yu, Ping [Department of Immunology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China); Wang, Shi-Ping [Key Laboratory of Schistosomiasis in Hunan, Department of Parasitology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China)

    2012-03-02

    Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.

  4. Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    2012-03-01

    Full Text Available Major histocompatibility complex class I chain-related A (MICA is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP and sequencing-based typing (SBT were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females. Fourteen MICA alleles and five short-tandem repeat (STR alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027 showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05. In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc 0.05. This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.

  5. Mapping lake level changes using ICESat/GLAS satellite laser altimetry data: a case study in arid regions of central Asia

    Science.gov (United States)

    Li, JunLi; Fang, Hui; Yang, Liao

    2011-12-01

    Lakes in arid regions of Central Asia act as essential components of regional water cycles, providing sparse but valuable water resource for the fragile ecological environments and human lives. Lakes in Central Asia are sensitive to climate change and human activities, and great changes have been found since 1960s. Mapping and monitoring these inland lakes would improve our understanding of mechanism of lake dynamics and climatic impacts. ICESat/GLAS satellite laser altimetry provides an efficient tool of continuously measuring lake levels in these poorly surveyed remote areas. An automated mapping scheme of lake level changes is developed based on GLAS altimetry products, and the spatial and temporal characteristics of 9 typical lakes in Central Asia are analyzed to validate the level accuracies. The results show that ICESat/GLAS has a good performance of lake level monitoring, whose patterns of level changes are the same as those of field observation, and the max differences between GLAS and field data is 3cm. Based on the results, it is obvious that alpine lakes are increasing greatly in lake levels during 2003-2009 due to climate change, while open lakes with dams and plain endorheic lakes decrease dramatically in water levels due to human activities, which reveals the overexploitation of water resource in Central Asia.

  6. Mysis diluviana and Hemimysis anomala: reviewing the roles of a native and invasive mysid in the Laurentian Great Lakes region

    Science.gov (United States)

    Walsh, Maureen G.; Boscarino, Brent T.; Marty, Jérôme; Johannsson, Ora E.

    2012-01-01

    Mysis diluviana and Hemimysis anomala are the only two species of mysid shrimps in the order Mysidacea that are present in the Laurentian Great Lakes of North America. M. diluviana has inhabited the deep, cold waters of this region since Pleistocene-era glacial retreat and is widely considered to have a central role in the functioning of offshore food webs in systems they inhabit. More recently, the Great Lakes were invaded by the Ponto-Caspian native Hemimysis, a species that inhabits warmer water and shallower depths relative to M. diluviana. Hemimysis has rapidly expanded throughout the Great Lakes region and has become integrated into nearshore food webs as both food for planktivorous fish and predators and competitors of zooplankton. This special issue is composed of 14 papers that represent the most recent advances in our understanding of the ecological importance of both species of mysids to lake and river ecosystems in the Great Lakes region of North America. Topics discussed in this special issue will inform future research in all systems influenced by mysid ecology.

  7. Habitat capacity for cougar recolonization in the Upper Great Lakes region.

    Directory of Open Access Journals (Sweden)

    Shawn T O Neil

    Full Text Available BACKGROUND: Recent findings indicate that cougars (Puma concolor are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. METHODOLOGY/PRINCIPAL FINDINGS: Using Geographic Information Systems (GIS, we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2 of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. CONCLUSIONS/SIGNIFICANCE: Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region.

  8. [Longitudinal investigation on intestinal parasite infections among rural people in West Dongting Lake region].

    Science.gov (United States)

    Hou, Guo-Hong; Xiao, Zeng; Yao, Xiao-Ming; Xiao, Jun-Wen; Zhou, Ying-Cai; Xie, Zhao-Mei; Yu, Qiu-Lan; Guo, Feng-Ying; Zhao, Zheng-Yuan

    2011-06-01

    The nylon pocket concentration method and modified Kato-Katz technique were used to detect the eggs of intestinal parasites and the iodine smear method was used for the detection of protozoa among the rural population in West Dongting Lake region. The infection rate of parasites in 2006 was 11.84%, and it declined by 86.63%, 81.34%, and 47.28%, respectively, compared to the rates in 1983, 1993, and 2003. Six major parasites were detected including Ascaris lumbricoides, Trichuris trichiura, Fasciolopsis buski, hookworm, Entamoeba histolytica and Giardia lamblia, and their infection rates were 8.60%, 6.41%, 1.75%, 0.14%, 2.50%, and 1.22%, respectively. The rate of multiple infections was 22.98%. The infection rates in the 5-9 years age group and 10-14 years age group were higher than those in other age groups.

  9. Environmental significance exploration to Tamarix Cone Age Layer in Lop Nur Lake region

    Institute of Scientific and Technical Information of China (English)

    XIA Xuncheng; ZHAO Yuanjie; WANG Fubao; CAO Qiongying

    2005-01-01

    @@ For a long time, it has been short of finding the appropriate dating materials to meet special demands in order to study environmental change in the modern desert areas with strong windy and sandy actions. Tamarix Cone Age Layer provides a new way to overcome this difficulty to some extent[1]. Contained in Tamarix Cone Age Layer, the features such as δ13C and C/N of fallen Tamarix leaves, and thickness and granule composition of sand layer materials have contained the information of climatic and environmental changes[2-4]. This paper has probed into the feasibility making use of Tamarix Cone Age Layer to reveal the environmental change in Lop Nur Lake region.

  10. PREDICTION OF THE LIKELIHOOD OF HOUSEHOLDS FOOD SECURITY IN THE LAKE VICTORIA REGION OF KENYA

    Directory of Open Access Journals (Sweden)

    Peter Nyamuhanga Mwita

    2011-06-01

    Full Text Available This paper considers the modeling and prediction of  households food security status using a sample of households in the  Lake Victoria region of Kenya. A priori expected food security  factors and their measurements are given. A binary logistic regression model  derived was fitted to thirteen priori expected factors. Analysis of the marginal effects revealed that effecting the use of the seven significant determinants: farmland size, per capita aggregate production, household size, gender of household head, use of fertilizer, use of pesticide/herbicide and education of household head,  increase the likelihood of a household being food secure. Finally, interpretations  of   predicted conditional probabilities, following improvement of significant determinants,  are given.

  11. Rangeland Grasshoppers in Relation to Soils in the Qinghai Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    NI Shao-Xiang; WANG Jie-Chen; JIANG Jian-Jun; ZHA Yong

    2007-01-01

    The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.

  12. Seismicity of Czorsztyn Lake Region: A Case of Reservoir Triggered Seismic Process?

    Directory of Open Access Journals (Sweden)

    Białoń Wojciech

    2015-08-01

    Full Text Available Czorsztyn Lake is an artificial water reservoir backed up by the hydropower plant Niedzica earth dam on Dunajec River in south Poland. Its filling began in 1995 and ended in 1997. The reservoir of 234.5 million m3 capacity is shallow, between 20 to 50 m of water column, on average. Until 2011 the seismic activity in this region was sparse, some 1 event trimonthly. However, in November 2011 more than 60 events occurred. Such bursts of activity, separated by low activity periods, continue to appear. Since August 2013 the area is monitored by a local seismic network. The setup allows to accurately locate the epicenters and to determine source mechanisms for stronger events. The events are clustered and aligned along NE-SW direction and their mechanisms are very similar, indicating N-S strike slip faulting. This and the irregular pattern of activity suggest that this seismicity is triggered by the reservoir impoundment

  13. Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar

    Directory of Open Access Journals (Sweden)

    Laure Guerrini

    2014-05-01

    Full Text Available While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist.

  14. Long-term recovery of lakes in the Adirondack region of New York to decreases in acidic deposition

    Science.gov (United States)

    Waller, Kristin; Driscoll, Charles; Lynch, Jason; Newcomb, Dani; Roy, Karen

    2012-01-01

    After years of adverse impacts to the acid-sensitive ecosystems of the eastern United States, the Acid Rain Program and Nitrogen Budget Program were developed to control sulfur dioxide (SO 2) and nitrogen oxide (NO x) emissions through market-based cap and trade systems. We used data from the National Atmospheric Deposition Program's National Trends Network (NTN) and the U.S. EPA Temporally Integrated Monitoring of Ecosystems (TIME) program to evaluate the response of lake-watersheds in the Adirondack region of New York to changes in emissions of sulfur dioxide and nitrogen oxides resulting from the Acid Rain Program and the Nitrogen Budget Program. TIME is a long-term monitoring program designed to sample statistically selected subpopulations of lakes and streams across the eastern U.S. to quantify regional trends in surface water chemistry due to changes in atmospheric deposition. Decreases in wet sulfate deposition for the TIME lake-watersheds from 1991 to 2007 (-1.04 meq m -2-yr) generally corresponded with decreases in estimated lake sulfate flux (-1.46 ± 0.72 meq m -2-yr), suggesting declines in lake sulfate were largely driven by decreases in atmospheric deposition. Decreases in lake sulfate and to a lesser extent nitrate have generally coincided with increases in acid neutralizing capacity (ANC) resulting in shifts in lakes among ANC sensitivity classes. The percentage of acidic Adirondack lakes (ANC Budget Program. Two measures of ANC were considered in our analysis: ANC determined directly by Gran plot analysis (ANC G) and ANC calculated by major ion chemistry (ANC calc = CB - CA). While these two metrics should theoretically show similar responses, ANC calc (+2.03 μeq L -1-yr) increased at more than twice the rate as ANC G (+0.76 μeq L -1-yr). This discrepancy has important implications for assessments of lake recovery and appears to be due to compensatory increases in concentrations of naturally occurring organic acids coincident with decreases in

  15. Transcending the Majority Rights and Minority Protection Dichotomy through Multicultural Reflective Citizenship in the African Great Lakes Region

    Science.gov (United States)

    Ndura, Elavie

    2006-01-01

    In this paper, the author examines how colonial racist policies and western-bound post-colonial educational practices have contributed to the recurring ethnic conflicts in the Great Lakes region of Africa. After defining democracy and reflective citizenship within the African context, she discusses how teachers' roles should be redefined and…

  16. Evaluation of Sugar Maple Dieback in the Upper Great Lakes Region and Development of a Forest Health Youth Education Program

    Science.gov (United States)

    Bal, Tara L.

    2013-01-01

    Sugar Maple, "Acer saccharum" Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as…

  17. An Overview of Interdisciplinary Research at Notre Dame Addressing "Grand Challenges" in the Midwest and Great Lakes Region

    Science.gov (United States)

    Hamlet, A. F.; Bolster, D.; Tank, J. L.; Hellmann, J.; Christopher, S. F.; Sharma, A.; Chiu, C. M.

    2014-12-01

    The Midwest and Great Lakes region face a number of "Grand Challenges" associated with climate, land use, agriculture, and water resources infrastructure. These include sustainability of agricultural systems and related impacts to food security and the regional economy; sustainability of Great Lakes water levels; changing storm statistics and impacts to stormwater management and flooding; water quality in rivers and downstream receiving water bodies related to non-point source pollution on agricultural lands and combined sewer overflows in urban areas; urban impacts related to aging infrastructure and climate change, and ecosystem management and restoration. In the context of water management, groundwater resources are poorly understood in comparison with surface water resources, and regional-scale simulation models are needed to address questions of sustainability both in terms of supply and water quality. Interdisciplinary research at the University of Notre Dame is attempting to address these research challenges via 1) integrated macro-scale groundwater and surface water modeling to address issues related to sustainable water supply, ecosystem restoration, and agricultural impacts; 2) development of high-resolution regional climate models dynamically coupled to the Great Lakes to address urban impacts, changing storm statistics and to quantify precipitation and evaporation over the Great Lakes; 3) and integrated macro-scale hydrology and water quality modeling to assess the large-scale performance of innovative land management BMPs on agricultural land (such as the two-stage ditch, cover crops, and dynamic drainage control) intended to improve water quality.

  18. New exposure ages for the Last Glacial Cycle in the Sanabria Lake region (northwestern Spain)

    Science.gov (United States)

    Rodríguez-Rodríguez, Laura; Jiménez-Sánchez, Montserrat; Domínguez-Cuesta, María Jose; Rinterknecht, Vincent; Pallàs, Raimon; Braucher, Régis; Bourlès, Didier; Valero-Garcés, Blas

    2013-04-01

    The Sanabria Lake region is located in the Trevinca Massif, a mid-latitude mountain area up to 2128 m asl in the northwest corner of the Iberian Peninsula (42oN 6oW). An ice cap glaciation took place during the Last Glacial Cycle in this massif, with an equilibrium line altitude of 1687 m for the Tera glacial outlet at its local maximum (Cowton et al., 2009). A well preserved glacial sequence occurs on an area of 45 km2 around the present Sanabria Lake (1000 m asl) and is composed by lateral and end moraines in close relationship with glaciolacustrine deposits. This sequence shows the ice snout oscillations of the former Tera glacier during the Last Glacial Cycle and offers a good opportunity to compare radiocarbon and OSL- based chronological models with new cosmogenic isotope dates. The new dataset of 10Be exposure ages presented here for the Sanabria Lake moraines is based on measurements conducted on 23 boulders and is compared with previous radiocarbon and OSL data conducted on ice related deposits (Pérez-Alberti et al., 2011; Rodríguez-Rodríguez et al., 2011). Our results are coherent with the available deglaciation radiocarbon chronology, and support a last deglaciation origin for the whole set of end moraines that are downstream the Sanabria Lake (19.2 - 15.7 10Be ka). Discrepancies between results of the different dating methods concern the timing of the local glacial maximum, with the cosmogenic exposure method always yielding the youngest minimum ages. As proposed to explain similar observations made elsewhere (Palacios et al., 2012), reconciling the ages from different dating methods would imply the occurrence of two glacial advances close enough in extent to generate an overlapping polygenic moraine. Cowton, T., Hughes, P.D., Gibbard, P.L., 2009. Palaeoglaciation of Parque Natural Lago de Sanabria, northwest Spain. Geomorphology 108, 282-291. Rodríguez-Rodríguez, L., Jiménez-Sánchez, M., Domínguez-Cuesta, M.J., Rico, M.T., Valero-Garcés, B

  19. Multi-Polarization ASAR Backscattering from Herbaceous Wetlands in Poyang Lake Region, China

    Directory of Open Access Journals (Sweden)

    Huiyong Sang

    2014-05-01

    Full Text Available Wetlands are one of the most important ecosystems on Earth. There is an urgent need to quantify the biophysical parameters (e.g., plant height, aboveground biomass and map total remaining areas of wetlands in order to evaluate the ecological status of wetlands. In this study, Environmental Satellite/Advanced Synthetic Aperture Radar (ENVISAT/ASAR dual-polarization C-band data acquired in 2005 is tested to investigate radar backscattering mechanisms with the variation of hydrological conditions during the growing cycle of two types of herbaceous wetland species, which colonize lake borders with different elevation in Poyang Lake region, China. Phragmites communis (L. Trin. is semi-aquatic emergent vegetation with vertical stem and blade-like leaves, and the emergent Carex spp. has rhizome and long leaves. In this study, the potential of ASAR data in HH-, HV-, and VV-polarization in mapping different wetland types is examined, by observing their dynamic variations throughout the whole flooding cycle. The sensitivity of ASAR backscattering coefficients to vegetation parameters of plant height, fresh and dry biomass, and vegetation water content is also analyzed for Phragmites communis (L. Trin. and Carex spp. The research for Phragmites communis (L. Trin. shows that HH polarization is more sensitive to plant height and dry biomass than HV polarization. ASAR backscattering coefficients are relatively less sensitive to fresh biomass, especially in HV polarization. However, both are highly dependent on canopy water content. In contrast, the dependence of HH- and HV- backscattering from Carex community on vegetation parameters is poor, and the radar backscattering mechanism is controlled by ground water level.

  20. Hazards Associated with High Altitude Rain-Fed Lakes (HARL) in the Overdeepened Deglaciated Region of Hindu Kush and Himalaya

    Science.gov (United States)

    Haritashya, U. K.; Hess, T. G.

    2014-12-01

    Mountain regions are changing rapidly as a result of climate change. It has been well established that these mountain regions are experiencing rapid glacier retreat. With accelerated retreat, glacial melt runoff can accumulate in an overdeepened glacier bed left behind by the receding glacier and can be bound by the walls of unstable frontal and lateral moraines to form a hazardous lake. However, when smaller glaciers retreat and downwaste they no longer contain enough ice to sustain the flow of water and maintain level of the lake. Furthermore, some smaller glaciers in the Hindu Kush and Himalayan region are observing extreme downwasting, which are either turning them into a rock glacier or heavily debris covered glacier leading to the reduced ice melt. Consequently, it is important to study these overdeepened beds, which are contained by the unstable mass. This is especially significant considering the great degree of complexity in the mountain weather system and recent examples of high intensity and short duration rainfall in the Hindu Kush region of Afghanistan, Karakoram region of Pakistan, and Central Himalayan region of India and Nepal. A precise understanding of mountain climate system is necessary, but so does these potentially deglaciated overdeepened beds where rain-fed lakes can form and increase systems hydrostatic pressure that can breach moraine containment and flood entire downstream region. Once lake has formed it possesses hydrological characteristics that are similar to the glacial lakes, which are known to put lives and infrastructure in danger. Therefore, in this study we evaluated overdeepened beds that are located in the complex topography and contained by abandoned or unstable lateral moraine using field and remote sensing satellite images. Our results provide degree of failure associated with these lakes based on the complex spatial and topological analysis as well as orographic distribution of the region. Such studies are not common in the

  1. Changes in winter air temperatures near Lake Michigan, 1851-1993, as determined from regional lake-ice records

    Science.gov (United States)

    Assel, R.A.; Robertson, Dale M.

    1995-01-01

    Records of freezeup and breakup dates for Grand Traverse Bay, Michigan, and Lake Mendota, Wisconsin, are among the longest ice records available near the Great Lakes, beginning in 185 1 and 1855, respectively. The timing of freezeup and breakup results from an integration of meteorological conditions (primarily air temperature) that occur before these events. Changes in the average timing of these ice-events are translated into changes in air temperature by the use of empirical and process-driven models. The timing of freezeup and breakup at the two locations represents an integration of air temperatures over slightly different seasons (months). Records from both locations indicate that the early winter period before about 1890 was - 15°C cooler than the early winter period after that time; the mean temperature has, however, remained relatively constant since about 1890. Changes in breakup dates demonstrate a similar 1.0-1 .5”C increase in late winter and early spring air temperatures about 1890. More recent average breakup dates at both locations have been earlier than during 1890-1940, indicating an additional warming of 1.2”C in March since about 1940 and a warming of 1 . 1°C in January-March since about 1980. Ice records at these sites will continue to provide an early indication of the anticipated climatic warming, not only because of the large response of ice cover to small changes in air temperature but also because these records integrate climatic conditions during the seasons (winter-spring) when most warming is forecast to occur. Future reductions in ice cover may strongly affect the winter ecology of the Great Lakes by reducing the stable environment required by various levels of the food chain. 

  2. Regional and monthly and clear-sky aerosol direct radiative effect (and forcing derived from the GlobAEROSOL-AATSR satellite aerosol product

    Directory of Open Access Journals (Sweden)

    G. E. Thomas

    2013-01-01

    Full Text Available Using the GlobAEROSOL-AATSR dataset, estimates of the instantaneous, clear-sky, direct aerosol radiative effect and radiative forcing have been produced for the year 2006. Aerosol Robotic Network sun-photometer measurements have been used to characterise the random and systematic error in the GlobAEROSOL product for 22 regions covering the globe. Representative aerosol properties for each region were derived from the results of a wide range of literature sources and, along with the de-biased GlobAEROSOL AODs, were used to drive an offline version of the Met Office unified model radiation scheme. In addition to the mean AOD, best-estimate run of the radiation scheme, a range of additional calculations were done to propagate uncertainty estimates in the AOD, optical properties, surface albedo and errors due to the temporal and spatial averaging of the AOD fields. This analysis produced monthly, regional estimates of the clear-sky aerosol radiative effect and its uncertainty, which were combined to produce annual, global mean values of (−6.7 ± 3.9 W m−2 at the top of atmosphere (TOA and (−12 ± 6 W m−2 at the surface. These results were then used to give estimates of regional, clear-sky aerosol direct radiative forcing, using modelled pre-industrial AOD fields for the year 1750 calculated for the AEROCOM PRE experiment. However, as it was not possible to quantify the uncertainty in the pre-industrial aerosol loading, these figures can only be taken as indicative and their uncertainties as lower bounds on the likely errors. Although the uncertainty on aerosol radiative effect presented here is considerably larger than most previous estimates, the explicit inclusion of the major sources of error in the calculations suggest that they are closer to the true constraint on this figure from similar methodologies, and point to the need for more, improved estimates of both global aerosol loading and aerosol optical properties.

  3. Regional and monthly and clear-sky aerosol direct radiative effect (and forcing derived from the GlobAEROSOL-AATSR satellite aerosol product

    Directory of Open Access Journals (Sweden)

    G. E. Thomas

    2012-07-01

    Full Text Available Using the GlobAEROSOL-AATSR dataset, estimates of the instantaneous, clear-sky, direct aerosol radiative effect and radiative forcing have been produced for the year 2006. Aerosol Robotic Network sun-photometer measurements have been used to characterise the random and systematic error in the GlobAEROSOL product for 22 regions covering the globe. Representative aerosol properties for each region have been derived from the results of a wide range of literature sources and, along with the de-biased GlobAEROSOL AODs, were used to drive an offline version of the Met Office unified model radiation scheme. In addition to the mean AOD, best-estimate run of the radiation scheme, a range of additional calculations were done to propagate uncertainty estimates in the AOD, optical properties, surface albedo and errors due to the temporal and spatial averaging of the AOD fields. This analysis produced monthly, regional estimates of the clear-sky aerosol radiative effect and its uncertainty, which produce annual, global mean values of (−6.7 ± 3.9 W m−2 at the top of atmosphere (TOA and (−12 ± 6 W m−2 at the surface. These results were then used to produce estimates of regional, clear-sky aerosol direct radiative forcing, using modelled pre-industrial AOD fields for 1750 calculated for the AEROCOM PRE experiment. However, as it was not possible to quantify the uncertainty in the pre-industrial aerosol loading, these figures can only be taken as indicative and their uncertainties as lower bounds on the likely errors. Although the uncertainty on aerosol radiative effect presented here is considerably larger than most previous estimates, the explicit inclusion of the major sources of error in the calculations suggest that they are closer to the true constraint on this figure from similar methodologies, and point to the need for more, improved estimates of both global aerosol loading and aerosol optical properties.

  4. Sedimentary record of hydrophobic organic compounds in relation to regional economic development: A study of Taihu Lake, East China

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guoqing, E-mail: liugq@szu.edu.c [Institute of Applied Nuclear Technology, Shenzhen University, Shenzhen 518060 (China); State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhang Gan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yantai Institute of Coastal Zone for Sustainable Development, Chinese Academy of Sciences, Yantai 264003 (China); Jin Zhangdong [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an 710075 (China); Li Jun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2009-11-15

    Sediment cores taken from Taihu Lake, East China were analyzed for polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polybrominated biphenyl ethers (PBDEs). The results showed a general sharp increase of HCH, DDT, PAH and PBDE concentrations in the surface layers, corresponding to a sedimentation time of 1980 and 1990 onward in the Meiliang Bay and Xukou Bay, respectively. The source of PAHs has largely transferred from petrogenic to pyrogenic origin, and good relationships were observed between sediment PAH concentrations and the regional gross domestic product. The sharp increase of DDTs in recent years may be related to the mobilization and migration of these chemicals from surface soil to lake sediment, as a result of enhanced soil run-off due to large scale land transform, as well as the contribution of current usage of dicofol and DDT-containing anti-fouling paints. - PAHs, DDTs and PBDEs are still increasing in the Taihu Lake sediment.

  5. Scenario-based water resources planning for utilities in the Lake Victoria region

    Science.gov (United States)

    Mehta, Vishal K.; Aslam, Omar; Dale, Larry; Miller, Norman; Purkey, David R.

    Urban areas in the Lake Victoria (LV) region are experiencing the highest growth rates in Africa. As efforts to meet increasing demand accelerate, integrated water resources management (IWRM) tools provide opportunities for utilities and other stakeholders to develop a planning framework comprehensive enough to include short term (e.g. landuse change), as well as longer term (e.g. climate change) scenarios. This paper presents IWRM models built using the Water Evaluation And Planning (WEAP) decision support system, for three towns in the LV region - Bukoba (Tanzania), Masaka (Uganda), and Kisii (Kenya). Each model was calibrated under current system performance based on site visits, utility reporting and interviews. Projected water supply, demand, revenues and costs were then evaluated against a combination of climate, demographic and infrastructure scenarios up to 2050. Our results show that water supply in all three towns is currently infrastructure limited; achieving existing design capacity could meet most projected demand until 2020s in Masaka beyond which new supply and conservation strategies would be needed. In Bukoba, reducing leakages would provide little performance improvement in the short-term, but doubling capacity would meet all demands until 2050. In Kisii, major infrastructure investment is urgently needed. In Masaka, streamflow simulations show that wetland sources could satisfy all demand until 2050, but at the cost of almost no water downstream of the intake. These models demonstrate the value of IWRM tools for developing water management plans that integrate hydroclimatology-driven supply to demand projections on a single platform.

  6. Genetic variation and population dispersal of Yangtze voles Microtus fortis calamorum in the Dongting Lake region

    Institute of Scientific and Technical Information of China (English)

    Zongming GUO; Pengfei SONG; Cong GUO; Zhaobin SONG; Yong WANG; Bo LI; Meiwen ZHANG; Jianghong RAN

    2012-01-01

    To understand genetic variation and population dispersal in the Yangtze vole Microtusfortis calamorum distributed in the Dongting Lake region,144 individuals were collected from six habitat patches.The mitochondrial DNA control region was sequenced and 17 haplotypes were observed.Of the six investigated populations,haplotype and nucleotide diversities of those from larger patches were higher than those from smaller patches.Nonparametric correlation analysis showed that patch size had a positive correlation with haplotype diversity (r =0.943,P < 0.01).A neighbour-joining tree of the 17 hapiotypes showed no geographic genetic structure among the six populations.Analysis of isolation by distance showed that genetic differentiation among the six populations was not positively related to geographic distance.Analysis of mismatch distribution indicated that the voles had passed through a population expansion.The pattern of haplotype distribution in the Changsha population suggests that the population was established by a founder effect [Current Zoology 58 (2):211-220,2012].

  7. Optimizing Nitrogen Fertilizer Application for Rice Production in the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    DENG Mei-Hua; SHI Xiao-Jun; TIAN Yu-Hua; YIN Bin; ZHANG Shao-Lin; ZHU Zhao-Liang; S. D. KIMURA

    2012-01-01

    To determine the optimal amount of nitrogen (N) fertilizer for achieving a sustainable rice production at the Taihu Lake region of China,two-year on-farm field experiments were performed at four sites using various N application rates.The results showed that 22%-30% of the applied N was recovered in crop and 7%-31% in soils at the rates of 100-350 kg N ha-1.Nitrogen losses increased with N application rates,from 44% of the applied fertilizer N at the rate of 100 kg N ha-1 to 69% of the N applied at 350 kg N ha-1.Ammonia volatilization and apparent denitrification were the main pathways of N losses.The N application rate of 300 kg N ha-1,which is commonly used by local farmers in the study region,was found to lead to a significant reduction in economic and environmental efficiency.Considering the cost for mitigating environmental pollution and the maximum net economic income,an application rate of 100-150 kg N ha-1 would be recommended.This recommended N application rate could greatly reduce N loss from 199 kg N ha-1 occurring at the N application rate of 300 kg N ha-1 to 80-110 kg N ha-1,with the rice grain yield still reaching 7300-8300 kg DW ha-1 in the meantime.

  8. Macro-Scale Correction of Precipitation Undercatch in the Midwest/Great Lakes Region

    Science.gov (United States)

    Chiu, C. M.; Hamlet, A. F.

    2015-12-01

    Precipitation gauge undercatch is a serious problem in the context of using observed meteorological data sets for hydrologic modeling studies in regions with cold winters, such as the Midwest. Attention to this matter is urgently needed to support hydroclimatological research efforts in the region. To support hydrologic modeling studies, a new hybrid gridded meteorological dataset at 1/16 degree resolution based on data from CO-OP station records, the U. S. Historical Climatology Network, the Historical Canadian Climate Database, and Precipitation Regression on Independent Slopes Method has been assembled over the Great Lakes and Midwest regions from 1915-2013 at daily time step. Preliminary hydrologic simulations results using the Variable Infiltration Capacity hydrology model with this hybrid gridded meteorological dataset showed that precipitation gauge undercatch was a very significant issue throughout the region, especially for winter snowfall and simulated streamflow, which were both grossly underpredicted. Correction of primary CO-OP station data is generally infeasible due to missing station meta data and lack of local-scale wind speed measurements. Instead, macro-scale post processing techniques were developed to adjust the regridded precipitation product from CO-OP station records from 1950-2013 forwards, accounting for undercatch as a function of regridded wind speed simulations obtained from NCAR Reanalysis. Comparisons of simulated and observed streamflow over seven river basins in the Midwest were used to evaluate the datasets constructed using different combinations of meteorological station inputs, with and without undercatch corrections. The comparisons show promise in producing corrected precipitation data sets from 1950-2013 for hydrologic modeling studies, with substantial improvements in streamflow simulation from the uncalibrated VIC model when gauge undercatch corrections are included.

  9. Housing Archetype Analysis for Home Energy-Efficient Retrofit in the Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. K.; Mrozowski, T.; Harrell-Seyburn, A.; Ehrlich, N.; Hembroff, L.; Bieburn, B.; Mazor, M.; McIntyre, A.; Mutton, C.; Parsons, G.; Syal, M. G.; Wilkinson, R.

    2014-09-01

    This project report details activities and results of the 'Market Characterization' project undertaken by the Cost Effective Energy Retrofit (CEER) team targeted toward the DOE goal of achieving 30%-50% reduction in existing building energy use. CEER consists of members from the Dow Chemical Company, Michigan State University, Ferris State University and Habitat for Humanity Kent County. The purpose of this market characterization project was to identify housing archetypes which are dominant within Great Lakes region and therefore offer significant potential for energy-efficient retrofit research and implementation due to the substantial number of homes possessing similar characteristics. Understanding the characteristics of housing groups referred to as 'archetypes' by vintage, style, and construction characteristics can allow research teams to focus their retrofit research and develop prescriptive solutions for those structure types which are prevalent and offer high potential uptake within a region or market. Key research activities included; literature review, statistical analysis of national and regional data of the American Housing Survey (AHS) collected by the U.S. Census Bureau, analysis of Michigan specific data, development of a housing taxonomy of architectural styles, case studies of two local markets (i.e., Ann Arbor and Grand Rapids in Michigan) and development of a suggested framework (or process) for characterizing local markets. In order to gain a high level perspective, national and regional data from the U.S. Census Bureau was analyzed using cross tabulations, multiple regression models, and logistic regression to characterize the housing stock and determine dominant house types using 21 variables.

  10. A review of factors affecting productivity of bald eagles in the Great Lakes region: implications for recovery.

    Science.gov (United States)

    Bowerman, W W; Giesy, J P; Best, D A; Kramer, V J

    1995-05-01

    The bald eagle (Haliaeetus leucocephalus) population in North America declined greatly after World War II due primarily to the eggshell thinning effects of p,p'-DDE, a biodegradation product of DDT. After the banning of DDT in the United States and Canada during the early 1970s, the bald eagle population started to increase. However, this population recovery has not been uniform. Eagles nesting along the shorelines of the North American Great Lakes and rivers open to spawning runs of anadromous fishes from the Great Lakes still exhibit impaired reproduction. We have explored both ecological and toxicological factors that would limit reproduction of bald eagles in the Great Lakes region. Based on our studies, the most critical factors influencing eagle populations are concentrations of environmental toxicants. While there might be some continuing effects of DDE, total PCBs and most importantly 2,3,7,8-tetrachlordibenzo-p-dioxin equivalents (TCDD-EQ) in fishes from the Great Lakes and rivers open to spawning runs of anadromous fishes from the Great Lakes currently represent a significant hazard to bald eagles living along these shorelines or near these rivers and are most likely related to the impaired reproduction in bald eagles living there.

  11. Quaternary volcanic-sedimentary sequences and evolution of the Llancanelo Lake region (Southern Mendoza, Western Argentina) evidenced from geoelectric methods

    Science.gov (United States)

    de la Vega, Matias; Lopez, Ernesto; Osella, Ana; Rovere, Elizabeth I.; Violante, Roberto A.

    2012-12-01

    Llancanelo Lake region (Southern Mendoza Province, Western Argentina) is a key area for investigating the regional evolution of a tectonic basin affected by intense arc- and back-arc volcanism. However, the lack of enough outcrops makes it difficult to perform such reconstructions. In order to solve this problem, and with the aim of depicting the subsurface stratigraphy, 22 geoelectric surveys reaching more than 100 m depth were performed. The applied methodology, that combined geoelectrical measurements and field observations, is a continuation of previous works carried out in the region, and allowed for the first time to establish a near-surface stratigraphy that records the last evolutive stages of the lake. The studied region is mainly composed of Quaternary volcanic and sedimentary sequences. Four units were recognized on the basis of the geoelectrical differences (resistivity signal) supported by field observations where they crop out. Two of them have very high resistivity and are composed of basaltic lava flows, hence indicating the volcanic influence in the region. The other two have very low resistivity and correspond to sedimentary deposits, being the uppermost one composed of lacustrine sediments. The units were named according to the well-known stratigraphic scheme valid for the region. The studied stratigraphic sequence encompasses the time-span from the Pliocene to the present, and its interpretation allowed to establish the main evolutive stages, characterized by a complex interaction among tectonic, volcanic and climatic factors. The damming of the lake by basaltic flows and the consequent reduction of the lake's extension at times of intensive volcanic activity is one of the most significant events in its evolution.

  12. Heavy metals accumulation in crab and shrimps from Pulicat lake, north Chennai coastal region, southeast coast of India.

    Science.gov (United States)

    Batvari, B Prabhu Dass; Sivakumar, S; Shanthi, K; Lee, Kui-Jae; Oh, Byung-Taek; Krishnamoorthy, R R; Kamala-Kannan, Seralathan

    2016-01-01

    The accumulation of heavy metals such as lead (Pb), iron (Fe), zinc (Zn), cadmium (Cd), and chromium (Cr) was examined in crab (Scylla serrata) and shrimps (Penaeus semisulcatus, Penaeus indicus, and Penaeus monodon) collected from Pulicat lake that receives effluents from industries located in north Chennai, southeast coast of India. The results showed limited difference between crab and prawns as well as significant variations between the organs. Pb is the highly accumulated metal in both crab and shrimps, except P. monodon. The highest metal concentration was mostly found in the liver followed by other organs. The concentration of metals in edible parts (muscle) was within the permissible level and safe for consumption. However, the results of the study clearly indicate the biomagnification of metals in Pulicat lake.

  13. Four Lakes from Mercator's Map of Croatian Regions and Causes of their Extinction

    OpenAIRE

    Krešimir Kužić

    2001-01-01

    The author proves the existence of four lakes on a Mercator's map from AD 1593. In the first part he explains the genesis of the map. The causes why the lakes disappeared and when it happened were adduced in the second part of the paper.

  14. Beta-Glucosidase Activity in Paddy Soils of the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Chang; LU Qin

    2006-01-01

    The profile distribution ofβ-gulcosidase activity in twelve typical paddy soil profiles with high productivity in the Taihu Lake region of China were investigated. Activities ofβ-gulcosidase in the plow layers were in the range of 52.68-137.02μg PNP g-1 soil h-1 with a mean of 89.22μg PNP g-1 soil h-1. However, most plow layers ranged from 70 to 110μg PNP g-1 soil h-1. The profile distribution of β-gulcosidase activity in the 12 soil profiles decreased rapidly with soil depth, with activity at the 60 cm depth only about 10% of that in the surface layers (0-15 cm or 0-20 cm). In these soil profiles, β-gulcosidase activity was significantly positively correlated with soil organic carbon and arylsulphatase activity.Meanwhile, a significantly negative correlation was shown betweenβ-gulcosidase activity and soil pH.

  15. Micrometeorological Measurements of Air-Surface Exchange Rates of PBTs in the Great Lakes Region

    Science.gov (United States)

    Tobias, D. E.; Perlinger, J. A.; Morrow, P.

    2002-12-01

    The fate of persistent bioaccumulative toxic chemicals (PBTs) in the environment is controlled by their exchange with various aquatic and terrestrial surfaces. Many of the PBTs are semivolatile and present in the atmosphere almost entirely in the vapor phase. The rate of exchange of these vapor phase chemicals can be predicted from physicochemical properties of the chemical and the surface and the meteorological conditions during the exchange. However, field studies of the uptake of the PBTs are extremely limited or nonexistent making it difficult to evaluate the modeled transfer velocities. This presentation describes a novel method to directly measure air-surface exchange rates of PBTs above aquatic and terrestrial surfaces by the micrometeorological technique known as the modified Bowen ratio approach. Simultaneous measurements of the air temperature, water vapor content, windspeed, and the chemical species concentration at two heights above the surface are required to derive the transfer velocity of the chemical. Advanced techniques that minimize the number of sample preparation steps are required to make the two concentration measurements with adequate relative accuracy. To accomplish this task, ambient air is sampled with a multicapillary column and the analytes are directly desorbed into a high-resolution gas chromatograph for quantitation. This presentation will summarize preliminary measurements made in the near-shore region of Upper Michigan's Keweenaw Peninsula on Lake Superior during the summer of 2001 and 2002.

  16. Fish consumption among women anglers of childbearing age in the Great Lakes region.

    Science.gov (United States)

    Connelly, Nancy A; Bruce Lauber, T; Niederdeppe, Jeff; Knuth, Barbara A

    2016-10-01

    Fish consumption advisories are issued by the federal government for women of childbearing age (WCBA). These advisories make recommendations about the amount and types of fish that should be consumed to provide the greatest health benefits to women and their children while avoiding risks from chemical contaminants. We used diary methods to study fish consumption patterns of 1395 WCBA in the Great Lakes coastal region who purchased fishing licenses, a group which has significant opportunity to eat larger quantities of fish. Very few members of this group reported exceeding the federal recommendations for total fish consumption (between 3% and 5% depending on assumptions about portion sizes), consumption of canned "white" tuna (0%), or consumption of "do not eat" species (4%). They did report eating more fish on average than recent national study estimates, but they did not report consuming as much fish as is recommended to obtain the greatest health benefits of fish consumption. Only 10-12% of study participants reported eating within the recommended range of 8-12oz. of fish per week, with 84-87% eating less than the recommended amount. Additional efforts are likely needed to encourage WCBA to eat more low-risk fish, even among this group of higher-than-average fish consumers.

  17. Invasion of Nostocales (cyanobacteria) to Subtropical and Temperate Freshwater Lakes - Physiological, Regional, and Global Driving Forces.

    Science.gov (United States)

    Sukenik, Assaf; Hadas, Ora; Kaplan, Aaron; Quesada, Antonio

    2012-01-01

    Similar to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria) to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of the native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases, global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases, regional changes in nutrient loads and in biotic conditions were attributed to the invasion events.

  18. Braided rivers, lakes and sabkhas of the upper Triassic Cifuncho formation, Atacama region, Chile

    Science.gov (United States)

    Suárez, M.; Bell, C. M.

    1994-01-01

    A 1,000-m-thickness of Upper Triassic (to possibly Hettangian) sediments of the Cifuncho Formation are exposed in the coastal Cordillera of the Atacama Region, Chile. These coarse-grained clastic terrigenous strata are interpreted as the deposits of braided rivers, ephemeral lakes, sabkhas and volcaniclastic alluvial fans. They include conglomerates, pebbly sandstones, fine to medium-grained sandstones and thin, finely-laminated limestones. Halite hopper-casts are abundant in sandstones near the top of the section. Approximately 90% of the clastic detritus was derived from an upper Paleozoic metasedimentary accretionary complex located to the west. Andesitic debris flow and pyroclastic flow deposits occur near the base of the sequence. Isolated tuff intercalations and an ignimbritic lava flow occur higher in the section. The great thickness of coarse-grained and ill-sorted clastic sediments suggests deposition in an actively subsiding basin, probably a graben, adjacent to rising highlands. Overlying Hettangian-Sinemurian marine sediments were deposited by a transgression which occurred during a world-wide lowstand. This suggests that thermal subsidence followed the Triassic rifting.

  19. Best Practices for Wind Energy Development in the Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Pebbles, Victoria; Hummer, John; Haven, Celia

    2011-07-19

    This report offers a menu of 18 different, yet complementary, preferred practices and policies. The best practices cover all phases of the wind energy development process - from the policies that allow for wind development, to the sustainable operation of a wind project, to the best practices for decommissioning a spent turbine - including applications for offshore wind. Each best practice describes the opportunities and challenges (pros and cons), and offers a case example that illustrates how that best practice is being utilized by a particular jurisdiction or wind project. The practices described in this publication were selected by a diverse group of interests from the Great Lakes Wind Collaborative that included environmental groups, industry, academia, and federal, state and local government regulators. The practices were identified through a year-long process that included a literature review, online survey and interviews with individuals from the public, private and non-profit sectors. Optimally, a suite of these best practices would be applied in an appropriate combination to fit the conditions of a particular wind project or a set of wind projects within a given locality or region.

  20. Residual Levels and New Inputs of Chlorinated POPs in Agricultural Soils from Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    GAO Hong-Jian; JIANG Xin; WANG Fang; BIAN Yong-Rong; WANG Dai-Zhang; DEND Jian-Cai; YAN Dong-Yun

    2005-01-01

    Selected persistent organochlorine pesticides (OCPs), including 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT)and its principal metabolites 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), hexachlorocyclohexane (HCH) and its isomers (α-, β-, γ-, and δ-HCH), hexachlorobenzene (HCB), endosulfan, dieldrin, and endrin were quantified to determine current levels of organochlorine pesticides, to assess the ecotoxicological potential, and to distinguish previous and current inputs in agricultural soils from the Taihu Lake region.Gas chromatography equipped with a 63Ni electron-capture detector (GC-ECD) system was employed. Thirteen OCPs were detectable in all soil samples, with DDTs being the main residues, and HCHs had the second highest level of OCP residues. Although OCP residual levels were lower than those in 1990s, the residual levels for most of the DDTs and some of HCHs were still higher than the national environmental standards for agricultural soils. The ratios of DDT/DDE and γ-/α-HCH in twelve soils indicated that new inputs could be present in the soils. Thus, efforts should be made to completely ban the production of OCPs and their use in agriculture so as to reduce the threat of OCPs to food quality and human health.

  1. Spatially explicit exposure assessment for small streams in catchments of the orchard growing region `Lake Constance

    Science.gov (United States)

    Golla, B.; Bach, M.; Krumpe, J.

    2009-04-01

    1. Introduction Small streams differ greatly from the standardised water body used in the context of aquatic risk assessment for the regulation of plant protection products in Germany. The standard water body is static, with a depth of 0.3 m and a width of 1.0 m. No dilution or water replacement takes place. Spray drift happens always in direction to the water body. There is no variability in drift deposition rate (90th percentile spray drift deposition values [2]). There is no spray drift filtering by vegetation. The application takes place directly adjacent to the water body. In order to establish a more realistic risk assessment procedure the Federal Office for Consumer Protection and Food Safety (BVL) and the Federal Environment Agency (UBA) aggreed to replace deterministic assumptions with data distributions and spatially explicit data and introduce probabilistic methods [3, 4, 5]. To consider the spatial and temporal variability in the exposure situations of small streams the hydraulic and morphological characteristics of catchments need to be described as well as the spatial distribution of fields treated with pesticides. As small streams are the dominant type of water body in most German orchard regions, we use the growing region Lake Constance as pilot region. 2. Materials and methods During field surveys we derive basic morphological parameters for small streams in the Lake Constance region. The mean water width/depth ratio is 13 with a mean depth of 0.12 m. The average residence time is 5.6 s/m (n=87) [1]. Orchards are mostly located in the upper parts of the catchments. Based on an authoritative dataset on rivers and streams of Germany (ATKIS DLM25) we constructed a directed network topology for the Lake Constance region. The gradient of the riverbed is calculated for river stretches of > 500 m length. The network for the pilot region consists of 2000 km rivers and streams. 500 km stream length are located within a distance of 150 m to orchards. Within

  2. Does landscape fragmentation influence sex ratio of dioecious plants? A case study of Pistacia chinensis in the Thousand-Island Lake region of China.

    Directory of Open Access Journals (Sweden)

    Lin Yu

    Full Text Available The Thousand-Island Lake region in Zhejiang Province, China is a highly fragmented landscape with a clear point-in-time of fragmentation as a result of flooding to form the reservoir. Islands in the artificial lake were surveyed to examine how population sex ratio of a dioecious plant specie Pistacia chinensis B. was affected by landscape fragmentation. A natural population on the mainland near the lake was also surveyed for comparison. Population size, sex ratio and diameter at breast height (DBH of individuals were measured over 2 years. More than 1,500 individuals, distributed in 31 populations, were studied. Soil nitrogen in the different populations was measured to identify the relationship between sex ratio and micro-environmental conditions. In accordance with the results of many other reports on biased sex ratio in relation to environmental gradient, we found that poor soil nitrogen areas fostered male-biased populations. In addition, the degree of sex ratio bias increased with decreasing population size and population connectivity. The biased sex ratios were only found in younger individuals (less than 50 years old in small populations, while a stable 1∶1 sex ratio was found in the large population on the mainland. We concluded that the effects of landscape fragmentation on the dioecious population sex ratio were mainly achieved in relation to changing soil nitrogen conditions in patches and pollen limitation within and among populations. Large populations could maintain a more suitable environment in terms of nutrient conditions and pollen flow, subsequently maintaining a stable sex ratio in dioecious plant populations. Both micro-environmental factors and spatial structure should be considered in fragmented landscape for the conservation of dioecious plant species.

  3. Distribution and diversity of diatom assemblages in surficial sediments of shallow lakes in Wapusk National Park (Manitoba, Canada) region of the Hudson Bay Lowlands.

    Science.gov (United States)

    Jacques, Olivier; Bouchard, Frédéric; MacDonald, Lauren A; Hall, Roland I; Wolfe, Brent B; Pienitz, Reinhard

    2016-07-01

    The hydrology of shallow lakes (and ponds) located in the western Hudson Bay Lowlands (HBL) is sensitive to climate warming and associated permafrost thaw. However, their biological characteristics are poorly known, which hampers effective aquatic ecosystem monitoring. Located in northern Manitoba along the southwestern coast of Hudson Bay, Wapusk National Park (WNP) encompasses numerous shallow lakes representative of the subarctic zone. We analyzed the distribution and diversity of diatom (microscopic algae; class Bacillariophyceae) assemblages in surficial sediments of 33 lakes located in three different ecozones spanning a vegetation gradient, from NE to SW: the Coastal Fen (CF), the Interior Peat Plateau (IPP), and the Boreal Spruce Forest (BSF). We found significant differences (P lakes, and CF and BSF lakes, but not between IPP and BSF lakes. These results are consistent with water chemistry measurements, which indicated distinct limnological conditions for CF lakes. Diatom communities in CF lakes were generally dominated by alkaliphilous taxa typical of waters with medium to high conductivity, such as Nitzschia denticula. In contrast, several IPP and BSF lakes were dominated by acidophilous and circumneutral diatom taxa with preference for low conductivity (e.g., Tabellaria flocculosa, Eunotia mucophila, E. necompacta var. vixcompacta). This exploratory survey provides a first detailed inventory of the diatom assemblages in the WNP region needed for monitoring programs to detect changes in shallow lake ecosystems and ecozonal shifts in response to climate variations.

  4. Hydroecological condition and potential for aquaculture in lakes of the arid region of Khorezm, Uzbekistan

    Science.gov (United States)

    Crootof, Africa; Mullabaev, Nodirbek; Saito, Laurel; Atwell, Lisa; Rosen, Michael R.; Bekchonova, Marhabo; Ginatullina, Elena; Scott, Julian; Chandra, Sudeep; Nishonov, Bakhriddin; Lamers, John P.A.; Fayzieva, Dilorom

    2015-01-01

    With >400 small (economy. Hydroecological (biological and physical) and chemical characteristics (including legacy pesticides ΣDDT and ΣHCH) of four representative drainage lakes in Khorezm from 2006 to 2008 were analyzed for the lakes’ capability to support healthy fish populations. Lake characteristics were categorized as “optimal” (having little or no effect on growth and development), “tolerable” (corresponding to chronic or sub-lethal toxicity) and “lethal” (corresponding to acute toxicity). Results indicate that three lakes are likely well-suited for raising fish species, with water quality meeting World Bank aquaculture guidelines. However, the fourth lake often had salinity concentrations > optimal levels for local fish species. Pesticide concentrations in water of all four lakes were within tolerable aquaculture ranges. Although water ΣDDT concentrations were >optimal limits, results from chemical analysis of fish tissues and semi-permeable membrane devices indicated that study lake ΣDDT concentrations were not accumulating in fish or posing a human health threat. Land and water management to maintain adequate lake water quality are imperative for sustaining fish populations for human consumption.

  5. Mosaic maternal ancestry in the Great Lakes region of East Africa.

    Science.gov (United States)

    Gomes, Verónica; Pala, Maria; Salas, Antonio; Álvarez-Iglesias, Vanesa; Amorim, António; Gómez-Carballa, Alberto; Carracedo, Ángel; Clarke, Douglas J; Hill, Catherine; Mormina, Maru; Shaw, Marie-Anne; Dunne, David W; Pereira, Rui; Pereira, Vânia; Prata, Maria João; Sánchez-Diz, Paula; Rito, Teresa; Soares, Pedro; Gusmão, Leonor; Richards, Martin B

    2015-09-01

    The Great Lakes lie within a region of East Africa with very high human genetic diversity, home of many ethno-linguistic groups usually assumed to be the product of a small number of major dispersals. However, our knowledge of these dispersals relies primarily on the inferences of historical, linguistics and oral traditions, with attempts to match up the archaeological evidence where possible. This is an obvious area to which archaeogenetics can contribute, yet Uganda, at the heart of these developments, has not been studied for mitochondrial DNA (mtDNA) variation. Here, we compare mtDNA lineages at this putative genetic crossroads across 409 representatives of the major language groups: Bantu speakers and Eastern and Western Nilotic speakers. We show that Uganda harbours one of the highest mtDNA diversities within and between linguistic groups, with the various groups significantly differentiated from each other. Despite an inferred linguistic origin in South Sudan, the data from the two Nilotic-speaking groups point to a much more complex history, involving not only possible dispersals from Sudan and the Horn but also large-scale assimilation of autochthonous lineages within East Africa and even Uganda itself. The Eastern Nilotic group also carries signals characteristic of West-Central Africa, primarily due to Bantu influence, whereas a much stronger signal in the Western Nilotic group suggests direct West-Central African ancestry. Bantu speakers share lineages with both Nilotic groups, and also harbour East African lineages not found in Western Nilotic speakers, likely due to assimilating indigenous populations since arriving in the region ~3000 years ago.

  6. Local and regional variability in fish community structure, richness and diversity of 56 Danish lakes with contrasting depth and trophic state

    DEFF Research Database (Denmark)

    Menezes, Rosemberg; Borchsenius, Finn; Svenning, J.-C.

    oligotrophic lakes due to high turbidity leading to loss of submerged macrophytes and thus habitat variability. Also the influence of piscivorous birds on the fish distribution in the littoral zone may differ between lake types leading to a more homogeneous distribution along the littoral area in eutrophic......Habitat distribution of fish might be influenced by food availability, competition, predation,composition of aquatic plants and water clarity. It has been found that a shift from a turbid to a clear water state in a lake lead to higher proportion of piscivorous fish and a habitat shift of prey fish...

  7. First record of Mylagaulid rodents (Rodentia, Mammalia) from the Miocene of Eastern Siberia (Olkhon Island, Baikal Lake, Irkutsk Region, Russia).

    Science.gov (United States)

    Tesakov, A S; Lopatin, A V

    2015-01-01

    A new genus and species of rodent, Lamugaulus olkhonensis, belonging to the subfamily Promylagaulinae of the family Mylagaulidae, is described on the basis of isolated teeth from the Khalagay Formation of the Lower Miocene Tagay locality (Olkhon island, Lake Baikal, Irkutsk Region). This is the first record of mylagaulids in Eastern Siberia, significantly expanding the data on the distribution of this mainly North American group of rodents in Asia and showing its presence outside the Central Asian arid zone.

  8. Modulation of aerosol radiative forcing due to mixing state in clear and cloudy-sky: A case study from Delhi National Capital Region, India

    Science.gov (United States)

    Srivastava, Parul; Dey, Sagnik; Srivastava, Atul K.; Singh, Sachchidanand; Tiwari, Suresh; Agarwal, Poornima

    2016-04-01

    Aerosol properties change with the change in mixing state of aerosols and therefore it is a source of uncertainty in estimated aerosol radiative forcing (ARF) from observations or by models assuming a specific mixing state. The problem is important in the Indo-Gangetic Basin, Northern India, where various aerosol types mix and show strong seasonal variations. Quantifying the modulation of ARF by mixing state is hindered by lack of knowledge about proper aerosol composition. Hence, first a detailed chemical composition analysis of aerosols for Delhi National capital region (NCR) is carried out. Aerosol composition is arranged quantitatively into five major aerosol types - accumulation dust, coarse dust, water soluble (WS), water insoluble (WINS), and black carbon (BC) (directly measured by Athelometer). Eight different mixing cases - external mixing, internal mixing, and six combinations of core- shell mixing (BC over dust, WS over dust, WS over BC, BC over WS, WS over WINS, and BC over WINS; each of the combinations externally mixed with other species) have been considered. The spectral aerosol optical properties - extinction coefficient, single scattering albedo (SSA) and asymmetry parameter (g) for each of the mixing cases are calculated and finally 'clear-sky' and 'cloudy-sky' ARF at the top-of-the-atmosphere (TOA) and surface are estimated using a radiative transfer model. Comparison of surface-reaching flux for each of the cases with MERRA downward shortwave surface flux reveals the most likely mixing state. 'BC-WINS+WS+Dust' show least deviation relative to MERRA during the pre-monsoon (MAMJ) and monsoon (JAS) seasons and hence is the most probable mixing states. During the winter season (DJF), 'BC-Dust+WS+WINS' case shows the closest match with MERRA, while external mixing is the most probable mixing state in the post-monsoon season (ON). Lowest values for both TOA and surface 'clear-sky' ARF is observed for 'BC-WINS+WS+ Dust' mixing case. TOA ARF is 0.28±2

  9. Assessment of Clear Sky Radiative Forcing in the Caribbean Region Using an Aerosol Dispersion Model and Ground Radiometry During Puerto Rico Dust Experiment

    Science.gov (United States)

    Gasso, Santiago; Qi, Qiang; Westpthal, Douglas; Reid, Jeffery; Tsay, Si-Chee

    2004-01-01

    This study investigates the surface and top of the atmosphere solar radiative forcing by long-range transport of Saharan dust. The calculations of radiative forcing are based on measurements collected in the Puerto Rico Dust Experiment (PRIDE) carried out during July, 2000. The purpose of the experiment was the characterization of the Saharan dust plume, which frequently reaches the Caribbean region during the summer. The experiment involved the use of three approaches to study the plume: space and ground based remote sensing, airborne and ground based in-situ measurements and aerosol dispersion modeling. The diversity of measuring platforms provides an excellent opportunity for determination of the direct effect of dust on the clear sky radiative forcing. Specifically, comparisons of heating rates, surface and TOA fluxes derived from the Navy global aerosol dispersion model NAAPS (NRL Aerosol Analysis and Prediction System) and actual measurements of fluxes from ground and space based platforms are shown. In addition, the direct effect of dust on the clear sky radiative forcing is modeled. The extent and time of evolution of the radiative properties of the plume are computed with the aerosol concentrations modeled by NAAPS. Standard aerosol parameterizations, as well as in-situ composition and size distributions measured during PRIDE, are utilized to compute the aerosol optical depth, single scattering albedo and asymmetry factor. Radiative transfer computations are done with an in-house modified spectral radiative transfer code (Fu-Liou). The code includes gas absorption and cloud particles (ice and liquid phase) and it allows the input of meteorological data. The code was modified to include modules for the aerosols contribution to the calculated fluxes. This comparison study helps to narrow the current uncertainty in the dust direct radiative forcing, as recently reported in the 2001 IPCC assessment.

  10. Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report first provides a description of the local community and economy near Sand Lake NWR. An analysis of current and proposed management strategies that could...

  11. Do singing-ground surveys reflect american woodcock abundance in the western Great Lakes region?

    Science.gov (United States)

    Matthew R. Nelson,; Andersen, David E.

    2013-01-01

    The Singing-ground Survey (SGS) is the primary monitoring tool used to assess population status and trends of American woodcock (Scolopax minor). Like most broad-scale surveys, the SGS cannot be directly validated because there are no independent estimates of abundance of displaying male American woodcock at an appropriate spatial scale. Furthermore, because locations of individual SGS routes have generally remained stationary since the SGS was standardized in 1968, it is not known whether routes adequately represent the landscapes they were intended to represent. To indirectly validate the SGS, we evaluated whether 1) counts of displaying male American woodcock on SGS routes related to land-cover types known to be related to American woodcock abundance, 2) changes in counts of displaying male American woodcock through time were related to changes in land cover along SGS routes, and 3) land-cover type composition along SGS routes was similar to land-cover type composition of the surrounding landscape. In Wisconsin and Minnesota, USA, counts along SGS routes reflected known American woodcock-habitat relations. Increases in the number of woodcock heard along SGS routes over a 13-year period in Wisconsin were related to increasing amounts of early successional forest, decreasing amounts of mature forest, and increasing dispersion and interspersion of cover types. Finally, the cover types most strongly associated with American woodcock abundance were represented along SGS routes in proportion to their composition of the broader landscape. Taken together, these results suggest that in the western Great Lakes region, the SGS likely provides a reliable tool for monitoring relative abundance and population trends of breeding, male American woodcock.

  12. Organic carbon stratification and size distribution of three typical paddy soils from Taihu Lake region, China

    Institute of Scientific and Technical Information of China (English)

    PAN Genxing; WU Laosheng; LI Lianqing; ZHANG Xuhui; GONG Wei; WOOD Yvonne

    2008-01-01

    Developing realistic soil carbon (C) sequestration strategies for China's sustainable agriculture relies on accurate estimates of the amount, retention and turnover rates of C stored in paddy soils. Available C estimates to date are predominantly for the tilled and flood-irrigated surface topsoil (ca. 30 cm). Such estimates cannot be used to extrapolate to soil depths of 100 cm since soil organic carbon (SOC) generally shows a sharp decrease with depth. In this research, composite soil samples were collected at several depths to 100 cm from three representative paddy soils in the Taihu Lake region, China. Soil organic carbon distribution in the profiles and in aggregate-size fractions was determined. Results showed that while SOC decreased exponentially with depth to 100 cm, a substantial proportion of the total SOC (30%-40%) is stored below the 30 cm depth. In the carbon-enriched paddy topsoils, SOC was found to accumulate preferentially in the 2-0.25 and 0.25-0.02 mm aggregate size fractions. d13C analysis of the coarse micro-aggregate fraction showed that the high degree of C stratification in the paddy topsoil was in agreement with the occurrence of lighter d1313C in the upper 30 cm depth. These results suggest that SOC stratification within profiles varies with different pedogenetical types of paddy soils with regards to clay and iron oxyhydrates distributions. Sand-sized fractions of aggregates in paddy soil systems may play a very important role in carbon sequestration and turnover, dissimilar to other studied agricultural systems.

  13. Description of the Microsporidian Parasite, Heterosporis sutherlandae n. sp., Infecting Fish in the Great Lakes Region, USA.

    Directory of Open Access Journals (Sweden)

    Nicholas B D Phelps

    Full Text Available Heterosporosis is an increasingly important microsporidian disease worldwide, impacting wild and farmed raised fishes in both marine and freshwater environments. A previously undescribed species (Heterosporis sp., with widespread distribution in the Great Lakes region, was the subject of this study. Three angler-caught fish were submitted to the Minnesota Veterinary Diagnostic Laboratory from 2009-2010 with lesions caused by intracellular proliferation of parasitic spores, resulting in destruction and eventual widespread necrosis of the host skeletal muscles. Mature ovoid (5.8 x 3.5 μm spores of a microsporidian parasite, consistent with the genus Heterosporis, were observed by light and electron microscopy. Molecular identification was performed using primer walking to obtain a near-complete rRNA gene sequence (~3,600 bp. A unique species of Heterosporis was identified, demonstrating less than 96% sequence identity to other published Heterosporis sp. on the basis of partial rRNA gene sequence analysis. Heterosporis sutherlandae n. sp. (formerly Heterosporis sp. was identified in yellow perch (Perca flavescens, northern pike (Esox lucius and walleye (Sander vitreus from inland lakes in Minnesota and Wisconsin. Previous research suggests this species may be even more widespread in the Great Lakes region and should be reexamined using molecular techniques to better understand the distribution of this novel species.

  14. Identifying risk factors of avian infectious diseases at household level in Poyang Lake region, China.

    Science.gov (United States)

    Jiang, Qian; Zhou, Jieting; Jiang, Zhiben; Xu, Bing

    2014-09-01

    Poultry kept in backyard farms are susceptible to acquiring and spreading infectious diseases because of free ranging and poor biosecurity measures. Since some of these diseases are zoonoses, this is also a significant health concern to breeders and their families. Backyard farms are common in rural regions of China. However, there is lack of knowledge of backyard poultry in the country. To obtain first-hand information of backyard poultry and identify risk factors of avian infectious diseases, a cross-sectional study was carried out at household level in rural regions around Poyang Lake. A door-to-door survey was conducted to collect data on husbandry practices, trading practices of backyard farmers, and surrounding environments of backyard farms. Farms were categorized into cases and controls based on their history of poultry death. Data were collected for 137 farms, and the association with occurrence of poultry death event was explored by chi-square tests. Results showed that vaccination implementation was a protective factor (odds ratio OR=0.40, 95% confidence interval CI: 0.20-0.80, p=0.01), while contact with other backyard flocks increased risk (OR=1.72, 95% CI: 0.79-3.74, p=0.16). A concept of "farm connectivity" characterized by the density of particular land-use types in the vicinity of the farm was proposed to characterize the degree of contact between poultry in one household farm and those in other household farms. It was found that housing density in a 20-m buffer zone of the farmhouse was most significantly associated with poultry death occurrence (OR=1.08, 95% CI: 1.02-1.17, p=0.03), and was in agreement with observation of villagers. Binary logistic regression was applied to evaluate the relationship between poultry death event and density of land-use types in all buffer zones. When integrated with vaccination implementation for poultry, prediction accuracy of poultry death event reached 72.0%. Results combining questionnaire survey with

  15. The 24 July 2008 outburst flood at the western Zyndan glacier lake and recent regional changes in glacier lakes of the Teskey Ala-Too range, Tien Shan, Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    C. Narama

    2010-04-01

    Full Text Available On 24 July 2008, a glacier lake outburst flood (GLOF occurred at the western (w- Zyndan glacier lake in the Tong District of Ysyk-Köl Oblast, Kyrgyzstan. The flood killed three people and numerous livestock, destroyed infrastructure, and devastated potato and barley crops as well as pastures. Tuurasuu village and a downstream reservoir on the Zyndan river escaped heavy damage because the main flood was diverted toward the Tong river. RTK-GPS and satellite data (Landsat 7 ETM+, ALOS/PRISM, and ALOS/AVNIR-2 reveal that the flood reduced the lake area from 0.0422 km2 to 0.0083 km2, discharging 437 000 m3 of water. This glacier lake was not present in a Landsat 7 ETM+ image taken on 26 April 2008. It formed rapidly over just two and half months from early May to the late July, when large amounts of snow and glacier melt water became trapped in a basin in the glacier terminus area, blocked by temporary closure of the drainage channel through the terminal moraine that included much dead-ice. In the same mountain region, most other glacier-lake expansions were not particularly large during the period from 1999–2008. Although events like the w-Zyndan glacier lake outburst occur infrequently in the high Central Asian mountains, such fast developing, short-lived lakes are particularly dangerous and not easy to monitor using satellite data. Appropriate measures to protect against such lake outburst hazards in this region include educating residents on glacier hazards and monitoring techniques, providing frequently updated maps of glacier lakes, and planning and monitoring land-use, including house locations.

  16. The 24 July 2008 outburst flood at the western Zyndan glacier lake and recent regional changes in glacier lakes of the Teskey Ala-Too range, Tien Shan, Kyrgyzstan

    Science.gov (United States)

    Narama, C.; Duishonakunov, M.; Kääb, A.; Daiyrov, M.; Abdrakhmatov, K.

    2010-04-01

    On 24 July 2008, a glacier lake outburst flood (GLOF) occurred at the western (w-) Zyndan glacier lake in the Tong District of Ysyk-Köl Oblast, Kyrgyzstan. The flood killed three people and numerous livestock, destroyed infrastructure, and devastated potato and barley crops as well as pastures. Tuurasuu village and a downstream reservoir on the Zyndan river escaped heavy damage because the main flood was diverted toward the Tong river. RTK-GPS and satellite data (Landsat 7 ETM+, ALOS/PRISM, and ALOS/AVNIR-2) reveal that the flood reduced the lake area from 0.0422 km2 to 0.0083 km2, discharging 437 000 m3 of water. This glacier lake was not present in a Landsat 7 ETM+ image taken on 26 April 2008. It formed rapidly over just two and half months from early May to the late July, when large amounts of snow and glacier melt water became trapped in a basin in the glacier terminus area, blocked by temporary closure of the drainage channel through the terminal moraine that included much dead-ice. In the same mountain region, most other glacier-lake expansions were not particularly large during the period from 1999-2008. Although events like the w-Zyndan glacier lake outburst occur infrequently in the high Central Asian mountains, such fast developing, short-lived lakes are particularly dangerous and not easy to monitor using satellite data. Appropriate measures to protect against such lake outburst hazards in this region include educating residents on glacier hazards and monitoring techniques, providing frequently updated maps of glacier lakes, and planning and monitoring land-use, including house locations.

  17. Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

    Science.gov (United States)

    Thompson, T.M.; Batts, W.N.; Faisal, M.; Bowser, P.; Casey, J.W.; Phillips, K.; Garver, K.A.; Winton, J.; Kurath, G.

    2011-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North Ame­rica. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from ­individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with ­previously naïve host populations.

  18. Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback

    Science.gov (United States)

    Austin, Jay A.; Colman, Steven M.

    2007-03-01

    Lake Superior summer (July-September) surface water temperatures have increased approximately 2.5°C over the interval 1979-2006, equivalent to a rate of (11 +/- 6) × 10-2°C yr-1, significantly in excess of regional atmospheric warming. This discrepancy is caused by declining winter ice cover, which is causing the onset of the positively stratified season to occur earlier at a rate of roughly a half day per year. An earlier start of the stratified season significantly increases the period over which the lake warms during the summer months, leading to a stronger trend in mean summer temperatures than would be expected from changes in summer air temperature alone.

  19. Low prevalence of VHSV detected in round goby collected in offshore regions of Lake Ontario

    Science.gov (United States)

    Cornwell, Emily R.; Getchell, Rodman G.; Groocock, Geoffrey H.; Walsh, Maureen G.; Bowser, Paul R.

    2012-01-01

    Since the first reports of mortalities due to viral hemorrhagic septicemia virus (VHSV) type IVb in the Laurentian Great Lakes basin during 2005 (Lake St. Clair, USA and Bay of Quinte, Lake Ontario, Canada), many groups have conducted surveillance efforts for the virus, primarily in nearshore areas. The round goby (Neogobius melanostomus) has been identified as a key species to target for surveillance, because they have a very high probability of infection at a given site. Our objective in this study was to document and quantify VHSV in round gobies in offshore waters of Lake Ontario using molecular techniques. We collected 139 round gobies from depths ranging from 55 to 150 m using bottom trawls during the early spring of 2011 and detected VHSV in 4 individuals (1/26 fish at 95 m, 2/12 fish at 105 m, and 1/24 fish at 135 m). These results expand the known depth range of VHSV in the Great Lakes. They also have implications on the management of the spread of VHSV within infected bodies of water related to the mixing of populations of fish that would remain distinct in their breeding habitats, but then have the opportunity to mix in their overwintering habitats, as well as to increase overlap of predator and prey species in overwintering habitats.

  20. Regional trends in evaporation loss and water yield based on stable isotope mass balance of lakes: The Ontario Precambrian Shield surveys

    Science.gov (United States)

    Gibson, J. J.; Birks, S. J.; Jeffries, D.; Yi, Y.

    2017-01-01

    Stable isotopes of water, oxygen-18 and deuterium, were measured in water samples collected from a network of 300 lakes sampled in six ∼100 km2 blocks (centred at 49.72°N, 91.46°W; 48.49°N, 91.58°W; 50.25°N, 86.62°W; 49.78°N, 83.98°W; 48.24°N, 85.49°W; 47.73, 84.52°W) within Precambrian shield drainages in the vicinity of Lake Superior, northern Ontario, Canada. Additional sampling was also conducted within the Turkey Lakes watershed (47.03°N, 84.38°W), a research basin situated in the Algoma region located 50 km north of Sault Saint Marie, Ontario. The studies were undertaken to gain a better understanding of hydrology and geochemistry of watersheds in the region in order to better predict acid sensitivity of lakes. The main objective of this paper is to describe the hydrologic variations observed based on stable isotope results. Evaporative isotopic enrichment of lake water was found to be systematic across the region, and its deviation from the isotopic composition of precipitation was used to estimate the evaporation/inflow to the lakes as well as runoff (or water yield) based on a simple isotope mass balance model. The analysis illustrates significant variability in the water yield to lakes and reveals a pattern of positively skewed distributions in all six widely spaced blocks, suggesting that a high proportion of lakes have relatively limited runoff whereas relatively few have greater runoff. Such basic information on the drainage structure of an area can be valuable for site-specific hydrologic assessments but also has significant implications for critical loads assessment, as low runoff systems tend to be less buffered and therefore are more sensitive to acidification. Importantly, the Turkey Lakes sampling program also suggests that isotope-based water yield is comparable in magnitude to hydrometric gauging estimates, and also establishes that uncertainty related to stratification can be as high as ±20% or more for individual lakes

  1. Landscape drivers of regional variation in the relationship between total phosphorus and chlorophyll in lakes

    Science.gov (United States)

    Wagner, T.; Soranno, P.A.; Webster, K.E.; Cheruvelil, K.S.

    2011-01-01

    For north temperate lakes, the well-studied empirical relationship between phosphorus (as measured by total phosphorus, TP), the most commonly limiting nutrient and algal biomass (as measured by chlorophyll a, CHL) has been found to vary across a wide range of landscape settings. Variation in the parameters of these TP-CHL regressions has been attributed to such lake variables as nitrogen/phosphorus ratios, organic carbon and alkalinity, all of which are strongly related to catchment characteristics (e.g. natural land cover and human land use). Although this suggests that landscape setting can help to explain much of the variation in ecoregional TP-CHL regression parameters, few studies have attempted to quantify relationships at an ecoregional spatial scale. We tested the hypothesis that lake algal biomass and its predicted response to changes in phosphorus are related to both local-scale features (e.g. lake and catchment) and ecoregional-scale features, all of which affect the availability and transport of covarying solutes such as nitrogen, organic carbon and alkalinity. Specifically, we expected that land use and cover, acting at both local and ecoregional scales, would partially explain the spatial pattern in parameters of the TP-CHL regression. We used a multilevel modelling framework and data from 2105 inland lakes spanning 35 ecoregions in six US states to test our hypothesis and identify specific local and ecoregional features that explain spatial heterogeneity in TP-CHL relationships. We include variables such as lake depth, natural land cover (for instance, wetland cover in the catchment of lakes and in the ecoregions) and human land use (for instance, agricultural land use in the catchment of lakes and in the ecoregions). There was substantial heterogeneity in TP-CHL relationships across the 35 ecoregions. At the local scale, CHL was negatively and positively related to lake mean depth and percentage of wooded wetlands in the catchment, respectively. At

  2. Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Lambert, Heather

    2005-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Sand Lake National Wildlife Refuge (NWR), located 27 miles northeast of Aberdeen, South Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Sand Lake NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

  3. Quantifying methane emissions from rice fields in Tai-Lake region, China by coupling detailed soil database with biogeochemical model

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2008-12-01

    Full Text Available China's paddy rice accounts for about 22% of the world's rice fields, therefore it is crucial to accurately estimate the CH4 emissions at regional scale to gauge their contribution to global greenhouse gas effect. This paper reports an application of a biogeochemical model, DeNitrification and DeComposition or DNDC, for quantifying CH4 emissions from rice fields in Tai-Lake region of China by linking DNDC to a 1:50 000 soil database, which was derived from 1107 paddy soil profiles in the Second National Soil Survey of China in the 1980s–1990s. The modeled results estimate that the 2.34 M ha of paddy rice fields in Tai-Lake region emitted about CH4 of 5.67 Tg C for the period of 1982–2000, with the average CH4 flux ranged from 114 to 138 kg C ha−1y−1. The highest emission rate (659.24 kg C ha−1 y−1 occurred in the subgroup of "gleyed paddy soils", while the lowest (90.72 kg C ha−1y−1 were associated with the subgroup "degleyed paddy soils". The subgroup "hydromorphic paddy soils" accounted for about 52.82% of the total area of paddy soils, the largest of areas of all the soil subgroups, with the CH4 flux rate of 106.47 kg C ha−1y−1. On a sub-regional basis, the annual average CH4 flux in the Tai-Lake plain soil region and alluvial plain soil region was higher than that in low mountainous and hilly soil region and polder soil region. The model simulation was conducted with two databases using polygon or county as the basic unit. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns CH4 emissions in Tai-Lake region. However, discrepancies exist between the results from the two methods, the relative deviation is

  4. Sahara and Sahel vulnerability to climate changes, lessons from the past - Focus on the Ounianga lake region (NE Chad)

    Science.gov (United States)

    Grenier, Christophe; Zheng, Weipeng; Lezine, Anne-Marie; Braconnot, Pascale; Krinner, Gerhard; Harel, Marie-Alice; Anglade, Juliette; Paillou, Philippe

    2010-05-01

    Reconstructions from sedimentary records and climate modelling results show an overall drying in the African Sahara and Sahel during the Holocene. Was this change abrupt or gradual, and amplified or not through vegetation change and feedbacks to the atmosphere is still the subject of debate. For instance, while [deMenocal et al. 2000] show from oceanic sediments off the Mauritanian coast, that the end of the African Humid Period (AHP), recorded 5500 years ago, was abrupt. [Kroepelin et al., 2008] studied recently sediments from lake Yoa (Ounianga region, NE Chad) and derived a gradual climate change. The present paper focusses on the Ounianga lake region (NE Chad) where the Kropelin et al. study was carried on. We investigate hydrological reconstructions based on climate scenarios and modelling of water dynamics of the catchment area of the lakes. Under modern conditions, Ounianga lakes are maintained in a hyper arid environment due to groundwater inputs from the Nubian Sandstone Aquifer System (NSAS), a very large aquifer covering parts of Chad, Libya, Egypt and Sudan. Moreover, these lakes are situated within 200 km of the Tibesti Mountains ranging over 3000 meters where rainfall is larger than in the plains. So the issue arises as to what extent distant water inputs from the Tibesti and local groundwater recharge could have maintained high lake levels during the climatic transition phase and/or could explain some features analysed from the sediments regarding the abruptness of the salinisation of lake Yoa roughly by 3900 BP. The topography of the region is analyzed from SRTM data to obtain paleo river networks and compared with satellite radar pictures (PALSAR) to identify key features in the Yoa catchement area [refer to Grenier et al. 2009]. A hydrological model is constructed including the river network and depressions interpreted as lakes and modeled dynamically as reservoirs. The groundwater input from the aquifer is modeled within the Cast3m finite element

  5. Chemical composition of halophytes from the Neusiedler Lake region in Austria.

    Science.gov (United States)

    Albert, R; Popp, Marianne

    1977-06-01

    The ionic relations in halophytes from the region east of Neusiedler Lake in Austria have been investigated. The study encompasses the following compounds: Na, K, Mg, Ca; Cl, SO4, phosphate, nitrate, and organic acids.The ionic composition varies substantially among the species investigated. Frequently a specific pattern of ion content can be found within a specific taxon. a) Dicotyledons: Extraordinary accumulation of sodium, high intake of inorganic ions (mainly Cl, less SO4), and regular occurrence of free oxalate, causing low Ca-concentrations, are typical for Chenopodiaceae and Caryophyllaceae (Spergularia media). Lepidium crassifolium shows similar sodium preponderance accompanied by high levels of SO4, Cl, and organic anions other than oxalate (mainly citrate and malate). The remaining dicotyledons show rather moderate salt content; Asteraceae and Cichoriaceae prefer Cl, and Plantago maritima accumulates high amounts of SO4 as well as Cl. Malate and citrate are, without exception, the main organic anions. The K:Na ratios in dicotyledons (esp. Chenopodiaceae and Lepidium-Brassicaceae) lie far below unity. b) Monocotyledons: In marked contrast, Poaceae, Cyperaceae, and Juncaceae are characterized by a general low salt status. With few exceptions, Cl is stored as the main inorganic anion, phosphate reaches higher levels than in dicotyledons and in many cases lies in nearly the same concentration range as SO4. The pattern of organic anions with malate and citrate as the main acids, does not basically differ from nonhalophilous species. In any case, K:Na ratio exceeds unity. Triglochin maritimum is the only monocotyle species exhibiting as high salt content and low K:Na ratios as dicotyledons. Nitrate and phosphate are of minor quantitative importance with regard to their osmotic efficiency; their mEq percentage of the total anion concentration range between 0.03 to 2.6 (NO3) and 0.5 to 13.6 (phosphate), respectively.The results are discussed from different

  6. Projected Precipitation Changes within the Great Lakes Region: A Multi-scale Analysis of Precipitation Intensity and Seasonality

    Science.gov (United States)

    Basile, S.; Steiner, A. L.; Brown, D.; Bryan, A. M.

    2014-12-01

    The Great Lakes region supports a diverse network of agriculture, transportation and tourism centered on some of the largest freshwater bodies of water in the world. Precipitation affects these sectors as concerns about precipitation timing and intensity can affect the agricultural growing season, runoff, and subsequent water quality. Here, we examine precipitation projections for mid-century (2041-2065) within the Great Lakes basin (GLB) and two sub-regions using three climate model ensembles of varying resolutions to constrain and compare associated precipitation uncertainties. These include: 1. atmosphere-ocean models from the CMIP5 global simulations with the RCP 8.5 scenario (12 members, resolution ranging from ~1 to ~3 degrees), 2. dynamically downscaled regional climate models from NARCCAP with the SRES A2 scenario (4 members at ~0.5 degree resolution (50 km)), and 3. high resolution (~0.25 degree resolution (25 km)) regional climate model simulations with the RCP 8.5 scenario (RegCM (hereafter RCM3(HiRes)), 2 members). For the entire GLB, all three ensembles captured the intensity of historical events well, but with a bias in the high intensity precipitation events as compared to observed intensity, with fewer overprediction events by the NARCCAP and RCM3(HiRes) ensembles. Daily probability density functions from three model ensembles reveal consistent increases in high precipitation event probabilities for all seasons, even after accounting for wet model biases during the observation period (1980-1999). Comparing all three ensembles to the historical period for the GLB, both CMIP5 and NARCCAP ensembles capture the annual seasonal cycle with a wet bias in the winter and spring, while the RCM3(HiRes) ensemble shows a dry bias for all seasons except winter. For the Lake Michigan and Western Lake Erie basin sub-regions, the spring and winter biases remain present across ensembles, however the RCM3(HiRes) summer dry bias is reduced. Overall, the three climate

  7. Imprints of Chilika Lake in the offshore region – A geomorphologic evidence

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Murthy, K.S.R.; Subrahmanyam, A; Rao, K.M.; Sarma, K.V.L.N; Reddy, N; Murty, G.P.S.; Devi, D.K.

    Chilika Lake (Orissa, India) is the largest lagoon in the subcontinent along the east coast of India, situated between latitudes 19 degrees 28’ and 19 degrees 54’ N and longitudes 85 degrees 05’ and 85 degrees 38’ E. In order to study the morphology...

  8. Seasonal radon measurements in Darbandikhan Lake water resources at Kurdistan region-northeastern of Iraq

    Science.gov (United States)

    Jafir, Adeeb Omer; Ahmad, Ali Hassan; Saridan, Wan Muhamad

    2016-03-01

    A total of 164 water samples were collected from Darbandikhan Lake with their different resources (spring, stream, and lake) during the four seasons, and the measurements were carried out using the electronic RAD 7 detector. For spring water the average radon concentration for spring, summer, autumn and summer were found to be 8.21 Bq/1, 8.94 Bq/1, 7.422 Bq/1, and 8.06 Bq/1, respectively, while for lake and streams the average values were found to be 0.43 Bq/1, 0.877 Bq/1, 0.727 Bq/1, 0.575 Bq/1 respectively. The radon concentration level was higher in summer and lower in spring, and only two samples from spring water have radon concentrations more than 11.1 Bq/1 recommended by the EPA. Total annual effective dose due to ingestion and inhalation has been estimated, the mean annual effective dose during the whole year for spring water was 0.022 mSv/y while for lake with streams was 0.00157 mSv/y. The determined mean annual effective dose in water was lower than the 0.1 mSv/y recommended by WHO. Some physicochemical parameters were measured and no correlation was found between them and radon concentration except for the conductivity of the spring drinking water which reveals a strong correlation for the four seasons.

  9. Impact of immigrant pastoral herds to fringing wetlands of lake Victoria in Magu district Mwanza region, Tanzania

    Science.gov (United States)

    Hongo, H.; Masikini, M.

    The assessment of impacts of pastoral herds to the fringing wetlands of Lake Victoria in Magu district in Mwanza region was carried out in 1999/2000. Lamadi village located along Speke Gulf of Lake Victoria was chosen. The main farming systems in the area are agriculture, agro-pastoralism, and pastoralism. The wetlands are heavily used for livestock grazing during the dry season. Since 1990s the area has been experiencing a high influx of immigrant pastoral herds from drought prone districts. The increasing livestock numbers have led into serious degradation of wetlands. The type of damages includes: soil erosion, loss of vegetation cover and deforestation. This lead to pollution of Lake Victoria along the Speke gulf in particular as the wetlands was buffering a lot of pollutants from the catchments. The range condition at Lamadi was rated fair. The carrying capacity of rangelands was estimated at 3.57-6.75 ha/LU and the wetlands were seriously degraded causing heavy soil erosion and environmental pollution during rainy season. It was recommended to raise people’s awareness on conservation of environment and mobilise communities to take responsibility on management of the environmental resources.

  10. Water resources management in the urban agglomeration of the Lake Biwa region, Japan: An ecosystem services-based sustainability assessment.

    Science.gov (United States)

    Chen, Xiaochen; Chen, Yuqing; Shimizu, Toshiyuki; Niu, Jia; Nakagami, Ken'ichi; Qian, Xuepeng; Jia, Baoju; Nakajima, Jun; Han, Ji; Li, Jianhua

    2017-05-15

    An innovative ecosystem services-based sustainability assessment was conducted in the important urban agglomeration of the Lake Biwa region, Japan, covering the time period from 1950 to 2014. A 22-indicator system was established that was based on the major ecosystem services of Lake Biwa and its water courses, i.e., provisioning services regarding aquatic products and water; regulating services regarding floods and water quality; cultural services regarding recreation and tourism, scientific research, and environmental education; and supporting services regarding biodiversity. First, changes in the eight ecosystem services were discussed together with the considerable experience and difficult lessons that can be drawn from the development trajectory. Next, with the indicators rearranged according to sustainability principles, the regional sustainability over the past six-plus decades was assessed. In general, this urban agglomeration has been progressing in terms of its sustainability, although economic and social development was achieved at the cost of environmental degradation in the past, and the current economic downturn is hurting the balanced development and integrated benefits. The results lead directly to recommendations for regional development, especially in terms of economic rejuvenation, from the perspective of improving management of Lake Biwa's water resources. Moreover, the relevant knowledge is educational and inspirational for other places in the world that are facing similar development issues. For example, the effective and even pioneering countermeasures that have been taken against environmental degradation, as well as the participation and collaboration of multiple stakeholders, could be useful as a model. Moreover, the study invites increased understanding of ecosystem vulnerability to anthropogenic devastation and emphasizes the priority of precautionary measures over countermeasures in the context of holistic urban planning and sustainable

  11. Problems with the claim of ecotype and taxon status of the wolf in the Great Lakes region

    Science.gov (United States)

    Cronin, Matthew A.; Mech, L. David

    2009-01-01

    Koblmuller et al. (2009) analysed molecular genetic data of the wolf in the Great Lakes (GL) region of the USA and concluded that the animal was a unique ecotype of grey wolf and that genetic data supported the population as a discrete wolf taxon. However, some of the literature that the researchers used to support their position actually did not, and additional confusion arises from indefinite use of terminology. Herein, we discuss the problems with designation of a wolf population as a taxon or ecotype without proper definition and assessment of criteria.

  12. Knowledge Sharing for Disaster Risk Reduction: Insights from a Glacier Lake Workshop in the Ladakh Region, Indian Himalayas

    Directory of Open Access Journals (Sweden)

    Naho Ikeda

    2016-02-01

    Full Text Available Small glacier lakes are distributed in the Ladakh Range in northwestern India. This area has experienced several glacier lake outburst floods (GLOFs since the 1970s, damaging settlements along streams. To reduce GLOF risk through a knowledge-based approach focused on nonstructural measures, we held a workshop in May 2012 for residents of Domkhar Village in the northwestern part of the Ladakh Range. More than 100 villagers participated in the workshop, which conveyed useful disaster information to participants while enabling the researchers to understand local knowledge and beliefs about floods. A survey conducted 3 months later confirmed an improvement in residents’ knowledge of natural disasters. The researchers also learned useful lessons, such as the need to adjust the program design for diverse participants and the importance of clearly communicating disaster risks and supporting local residents’ attempts to incorporate new scientific knowledge into existing local knowledge. Challenges to implementing flood countermeasures in this area included problems relating to land use and emergency communications and the need for coordination of efforts by the government and local residents.

  13. Direct heat applications of geothermal energy in The Geysers/Clear Lake region. Volume I. Geotechnical assessment, agribusiness applications, socioeconomic assessment, engineering assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    The different uses to which geothermal heat and fluids could be applied as a direct utilization of resource or as heat utilization are explored. The following aspects are covered: geotechnical assessment, agricultural and industrial applications, socioeconomic assessment, and engineering assessment. (MHR)

  14. Analysis of regional rainfall-runoff parameters for the Lake Michigan Diversion hydrological modeling

    Science.gov (United States)

    Soong, David T.; Over, Thomas M.

    2015-01-01

    The Lake Michigan Diversion Accounting (LMDA) system has been developed by the U.S. Army Corps of Engineers, Chicago District (USACE-Chicago) and the State of Illinois as a part of the interstate Great Lakes water regulatory program. The diverted Lake Michigan watershed is a 673-square-mile watershed that is comprised of the Chicago River and Calumet River watersheds. They originally drained into Lake Michigan, but now flow to the Mississippi River watershed via three canals constructed in the Chicago area in the early twentieth century. Approximately 393 square miles of the diverted watershed is ungaged, and the runoff from the ungaged portion of the diverted watershed has been estimated by the USACE-Chicago using the Hydrological Simulation Program-FORTRAN (HSPF) program. The accuracy of simulated runoff depends on the accuracy of the parameter set used in the HSPF program. Nine parameter sets comprised of the North Branch, Little Calumet, Des Plaines, Hickory Creek, CSSC, NIPC, 1999, CTE, and 2008 have been developed at different time periods and used by the USACE-Chicago. In this study, the U.S. Geological Survey and the USACE-Chicago collaboratively analyzed the parameter sets using nine gaged watersheds in or adjacent to the diverted watershed to assess the predictive accuracies of selected parameter sets. Six of the parameter sets, comprising North Branch, Hickory Creek, NIPC, 1999, CTE, and 2008, were applied to the nine gaged watersheds for evaluating their simulation accuracy from water years 1996 to 2011. The nine gaged watersheds were modeled by using the three LMDA land-cover types (grass, forest, and hydraulically connected imperviousness) based on the 2006 National Land Cover Database, and the latest meteorological and precipitation data consistent with the current (2014) LMDA modeling framework.

  15. Geological study of the volcanic cover in the lake regions of Bolsena, Vico, and Bracciano

    Energy Technology Data Exchange (ETDEWEB)

    Baldi, P. (ENEL, DSR, Centro di Ricerca Geotermica, Pisa, IT); Decandia, F.A.; Lazzarotto, A.; Calamai, A.

    1974-01-01

    During the course of geothermal exploration by ENEL in the northern Latium, Italy, the geology of the area was mapped in detail. Several deep wells, 140 test wells, and advanced geophysical survey techniques were applied in lithostratigraphic and paleochronological reconstruction of tectonic events from the Upper Miocene to the Quaternary. These reconstructions are presented in a series of illustrations. The hydrological character of the area was also determined and the structural controls on the sources of the lakes in the area were mapped.

  16. Spatial distribution of human Schistosoma japonicum infections in the Dongting Lake Region, China.

    Directory of Open Access Journals (Sweden)

    Giovanna Raso

    Full Text Available BACKGROUND: The aim of this study was to spatially model the effect of demographic, reservoir hosts and environmental factors on human Schistosoma japonicum infection prevalence in the Dongting Lake area of Hunan Province, China and to determine the potential of each indicator in targeting schistosomiasis control. METHODOLOGY/PRINCIPAL FINDINGS: Cross-sectional serological, coprological and demographic data were obtained from the 2004 nationwide periodic epidemiologic survey for Hunan Province. Environmental data were downloaded from the USGS EROS data centre. Bayesian geostatistical models were employed for spatial analysis of the infection prevalence among study participants. A total of 47,139 participants from 47 administrative villages were selected. Age, sex and occupation of residents and the presence of infected buffaloes and environmental factors, i.e. NDVI, distance to the lake and endemic type of setting, were significantly associated with S. japonicum infection prevalence. After taking into account spatial correlation, however, only demographic factors (age, sex and occupation and the presence of infected buffaloes remained significant indicators. CONCLUSIONS/SIGNIFICANCE: Long established demographic factors, as well presence of host reservoirs rather than environmental factors are driving human transmission. Findings of this work can be used for epidemiologic surveillance and for the future planning of interventions in the Dongting Lake area of Hunan Province.

  17. Cholera in the Lake Kivu region (DRC): Integrating remote sensing and spatially explicit epidemiological modeling

    Science.gov (United States)

    Finger, Flavio; Knox, Allyn; Bertuzzo, Enrico; Mari, Lorenzo; Bompangue, Didier; Gatto, Marino; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2014-07-01

    Mathematical models of cholera dynamics can not only help in identifying environmental drivers and processes that influence disease transmission, but may also represent valuable tools for the prediction of the epidemiological patterns in time and space as well as for the allocation of health care resources. Cholera outbreaks have been reported in the Democratic Republic of the Congo since the 1970s. They have been ravaging the shore of Lake Kivu in the east of the country repeatedly during the last decades. Here we employ a spatially explicit, inhomogeneous Markov chain model to describe cholera incidence in eight health zones on the shore of the lake. Remotely sensed data sets of chlorophyll a concentration in the lake, precipitation and indices of global climate anomalies are used as environmental drivers in addition to baseline seasonality. The effect of human mobility is also modelled mechanistically. We test several models on a multiyear data set of reported cholera cases. The best fourteen models, accounting for different environmental drivers, and selected using the Akaike information criterion, are formally compared via proper cross validation. Among these, the one accounting for seasonality, El Niño Southern Oscillation, precipitation and human mobility outperforms the others in cross validation. Some drivers (such as human mobility and rainfall) are retained only by a few models, possibly indicating that the mechanisms through which they influence cholera dynamics in the area will have to be investigated further.

  18. Clearing the Waters

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Taihu Lake is slowly improving after two years of pollution treatment,but more work remains Just two years ago, a layer of blue-green algae measuring up to 50 cm thick on Taihu Lake emitted a foul stench, while floating debris turned the water body into an eyesore and a blight. These days, though, the lake’s shoreline is alive with activity. Children laugh and

  19. Schistosomiasis research in the dongting lake region and its impact on local and national treatment and control in China.

    Directory of Open Access Journals (Sweden)

    Donald P McManus

    2011-08-01

    Full Text Available Schistosomiasis is a chronic and debilitating parasitic disease that has often been neglected because it is a disease of poverty, affecting poor rural communities in the developing world. This is not the case in the People's Republic of China (PRC, where the disease, caused by Schistosoma japonicum, has long captured the attention of the Chinese authorities who have, over the past 50-60 years, undertaken remarkably successful control programs that have substantially reduced the schistosomiasis disease burden. The Dongting Lake region in Hunan province is one of the major schistosome-endemic areas in the PRC due to its vast marshland habitats for the Oncomelania snail intermediate hosts of S. japonicum. Along with social, demographic, and other environmental factors, the recent completion and closure of the Three Gorges dam will most likely increase the range of these snail habitats, with the potential for re-emergence of schistosomiasis and increased transmission in Hunan and other schistosome-endemic provinces being a particular concern. In this paper, we review the history and the current status of schistosomiasis control in the Dongting Lake region. We explore the epidemiological factors contributing to S. japonicum transmission there, and summarise some of the key research findings from studies undertaken on schistosomiasis in Hunan province over the past 10 years. The impact of this research on current and future approaches for sustainable integrated control of schistosomiasis in this and other endemic areas in the PRC is emphasised.

  20. Comparative study on lake eutrophication control standards in Eastern and Yunnan-Guizhou lake region of China.%我国东部与云贵湖区富营养化控制标准对比研究

    Institute of Scientific and Technical Information of China (English)

    许秋瑾; 朱延忠; 郑丙辉; 赵伟

    2011-01-01

    Based on the monitoring data of main lakes in China's eastern and Yunnan-Guizhou region from 2005 to 2008, as well as the internationally recognized chlorophyll-a (Chla) concentration categories for lake eutrophication, statistical analysis was conducted on Chlorophyll a, total nitrogen (TN), total phosphorus (TP), transparency (SD) and permanganate index (CODMn) through method of frequency statistics. The recommended values for lake eutrophication control indicators in the two lake regions were calculated in accordance with the principle of anti-degradation. Shana results that the recommended values for lake eutrophication control indicators in China's eastern lake region should be TN at 1.65 mg/L,TP at 0.100mg/L,SD at 0.45m and CODMn at 4.50mg/L, while that in Yunnan-Guizhou lake region should be TN at 1.00mg/L,TP at 0.045 mg/L,SD at 1.10m and CODMn at 4.00mg/L. The absolute value of indicators for nitrogen and phosphorus nutrient control in Yunnan-Guizhou Plateau lake region is lower than that in eastern lake region. Thus, the control standard is comparatively higher in Yunnan-Guizhou Plateau lake region. The main reason is that the general water environmental quality in lakes of China's eastern plain region is currently worse than that in Yunnan-Guizhou Plateau region, because of intense interference by human activities.%以我国东部湖区及云贵湖区主要湖泊2005~2008年的监测数据和国际公认的湖泊富营养化叶绿素a含量分级为基础,通过频率统计方法,对叶绿素a、总氮(TN)、总磷(TP)、透明度(SD)和高锰酸盐指数(CODMn)进行了统计分析,并根据反退化原则,计算了两湖区湖泊富营养化控制指标的建议值.结果表明,东部湖区湖泊富营养化控制标准的建议值为TN:1.65mg/L,TP:0.100mg/L,SD:0.45m,CODMn:4.50mg/L;云贵湖区为TN:1.00 mg/L,TP:0.045 mg/L,SD:1.10m,CODMn:4.00mg/L.云贵高原湖区氮磷营养盐控制指标值绝对值低,相应控制标准比东部平原湖区严,

  1. Increasing risk of glacial lake outburst floods as a consequence of climate change in the Himalayan region

    Directory of Open Access Journals (Sweden)

    Somana Riaz

    2014-03-01

    Full Text Available The greater Himalayan Mountains host the largest snow covered area outside the polar regions and serves as the source for some of the major fluvial systems of the world. The region acts as the lifeline for approximately 10% of the world’s population. The terrain is geologically active, highly susceptible to climate change processes and plays a significant role in global hydro-meteorological cycles and biodiversity. With the increasing impacts of climate change to the glaciers and ice caps during the past few decades, people living in the Himalayas have become vulnerable to a higher risk of floods, avalanches and glacial lake outburst floods(GLOFs. This study reviewed the work carried out by earlier researchers to understand the history and science of GLOFs and their potential risk to the communities in the Himalayanbelt, particularly in Pakistan.

  2. Immune factors and fatty acid composition in human milk from river/lake, coastal and inland regions of China.

    Science.gov (United States)

    Urwin, Heidi J; Zhang, Jian; Gao, Yixiong; Wang, Chunrong; Li, Lixiang; Song, Pengkun; Man, Qingqing; Meng, Liping; Frøyland, Livar; Miles, Elizabeth A; Calder, Philip C; Yaqoob, Parveen

    2013-06-01

    Breast milk fatty acid composition may be affected by the maternal diet during gestation and lactation. The influence of dietary and breastmilk fatty acids on breast milk immune factors is poorly defined. We determined the fatty acid composition and immune factor concentrations of breast milk from women residing in river/lake, coastal and inland regions of China, which differ in their consumption of lean fish and oily fish. Breast milk samples were collected on days 3–5 (colostrum), 14 and 28 post-partum (PP) and analysed for soluble CD14 (sCD14), transforming growth factor (TGF)-b1, TGF-b2, secretory IgA (sIgA) and fatty acids. The fatty acid composition of breast milk differed between the regions and with time PP. The concentrations of all four immune factors in breast milk decreased over time, with sCD14, sIgA and TGF-b1 being highest in the colostrum in the river and lake region. Breast milk DHA and arachidonic acid (AA) were positively associated, and g-linolenic acid and EPA negatively associated, with the concentrations of each of the four immune factors. In conclusion, breast milk fatty acids and immune factors differ between the regions in China characterised by different patterns of fish consumption and change during the course of lactation. A higher breast milk DHA and AA concentration is associated with higher concentrations of immune factors in breast milk, suggesting a role for these fatty acids in promoting gastrointestinal and immune maturation of the infant.

  3. Factors related to northern goshawk landscape use in the western Great Lakes region

    Science.gov (United States)

    Bruggeman, Jason E.; Andersen, David E.; Woodford, James E.

    2014-01-01

    Northern Goshawks (Accipiter gentilis) are a species of special conservation concern in the western Great Lakes bioregion and elsewhere in North America, and exhibit landscape-scale spatial use patterns. However, little information exists about Northern Goshawk habitat relations at broad spatial extents, as most existing published information comes from a few locations of relatively small spatial extent and, in some cases, short durations. We used an information-theoretic approach to evaluate competing hypotheses regarding factors (forest canopy cover, successional stage, and heights of the canopy top and base) related to odds of Northern Goshawk landscape use throughout the western Great Lakes bioregion based on an occupancy survey completed in 2008 (Bruggeman et al. 2011). We also combined these data with historical data of Northern Goshawk nest locations in the bioregion from 1979–2006 to evaluate the same competing hypotheses to elucidate long-term trends in use. The odds of Northern Goshawk use in 2008, and from 1979–2008, were positively correlated with average percent canopy cover. In the best-approximating models developed using 1979–2008 data, the odds of landscape use were positively correlated with the percentages of the landscape having canopy heights between 10 m and 25 m, and 25 m and 50 m, and the amount of variability in canopy base height. Also, the odds of landscape use were negatively correlated with the average height at the canopy base. Our results suggest multiple habitat factors were related to Northern Goshawk landscape-scale habitat use, similar to habitat use described at smaller spatial scales in the western Great Lakes bioregion and in western North America and Europe.

  4. Phytoplankton and littoral epilithic diatoms in high mountain lakes of the Adamello-Brenta Regional Park (Trentino, Italy and their relation to trophic status and acidification risk

    Directory of Open Access Journals (Sweden)

    Monica TOLOTTI

    2001-08-01

    Full Text Available A survey of phytoplankton and littoral epilithic diatom communities was carried out on 16 high mountain lakes in the Adamello- Brenta Regional Park (NE Italy as part of a wider research project aimed to the limnological characterisation of the seldom-studied lakes in this Alpine Region. The regional study was supplemented by the analysis of seasonal variations in two representative lakes. The principal goals of this paper are 1 to identify the most important environmental variables regulating patterns in the species composition of both phytoplankton and littoral diatoms, 2 to evaluate whether these algal communities can be used to improve trophic classification and 3 whether they can facilitate monitoring of diffuse human impacts (e.g. airborne pollution on high altitude lakes. The relevance to monitoring is based on the acid sensitivity of all lakes studied, as indicated by the very low average alkalinity values (4-97 μeq l-1 recorded during the investigation period. Chlorophyll-a concentrations and phytoplankton biovolume recorded in the lakes were very low, with maxima in the deep-water layers and in late summer. Phytoplankton communities were dominated by flagellated algae (Chrysophyceae and Dinophyceae. Several coccal green algae were present, while planktonic diatoms were almost completely absent. Littoral diatom communities were dominated by alpine and acidophilous taxa (mainly belonging to the genera Achnanthes and Eunotia. Trophic classification based on phytoplankton and littoral diatoms, respectively, ascribed all lakes to the oligotrophic range. In both algal communities species indicative of acidified conditions were found. Multivariate analyses indicated that both the regional distribution and seasonal variation of phytoplankton are mainly driven by nutrient concentration. Diatoms are predominantly affected by geochemical characteristics including pH and mineralization level.

  5. A relative vulnerability estimation of flood disaster using data envelopment analysis in the Dongting Lake region of Hunan

    Directory of Open Access Journals (Sweden)

    C.-H. Li

    2013-07-01

    Full Text Available The vulnerability to flood disaster is addressed by a number of studies. It is of great importance to analyze the vulnerability of different regions and various periods to enable the government to make policies for distributing relief funds and help the regions to improve their capabilities against disasters, yet a recognized paradigm for such studies seems missing. Vulnerability is defined and evaluated through either physical or economic–ecological perspectives depending on the field of the researcher concerned. The vulnerability, however, is the core of both systems as it entails systematic descriptions of flood severities or disaster management units. The research mentioned often has a development perspective, and in this article we decompose the overall flood system into several factors: disaster driver, disaster environment, disaster bearer, and disaster intensity, and take the interaction mechanism among all factors as an indispensable function. The conditions of flood disaster components are demonstrated with disaster driver risk level, disaster environment stability level and disaster bearer sensitivity, respectively. The flood system vulnerability is expressed as vulnerability = f(risk, stability, sensitivity. Based on the theory, data envelopment analysis method (DEA is used to detail the relative vulnerability's spatiotemporal variation of a flood disaster system and its components in the Dongting Lake region. The study finds that although a flood disaster system's relative vulnerability is closely associated with its components' conditions, the flood system and its components have a different vulnerability level. The overall vulnerability is not the aggregation of its components' vulnerability. On a spatial scale, zones central and adjacent to Dongting Lake and/or river zones are characterized with very high vulnerability. Zones with low and very low vulnerability are mainly distributed in the periphery of the Dongting Lake region

  6. The Role of Lake-Dotted Landscapes in Regional Climate Change as Illustrated by Spatial and Temporal Analysis of Historic Lake-Level Change in Minnesota, USA

    Science.gov (United States)

    Plank, C. P.; Shuman, B. N.

    2006-12-01

    The relatively young Holocene landscape of the upper Midwest contains over 37,900 lakes in Michigan, Wisconsin, and Minnesota alone. Within the state of Minnesota, the inland lakes (excluding the coast of Lake Superior) combine to cover over 9815 km2 of area. This open water surface area constitutes 4.57% of the total state area and represents a significant expression of the moisture available to the landscape. However, the physical dimensions of lakes fluctuate significantly as moisture balance changes. We use observations of temperature, precipitation, and lake area taken from the 1930's "Dust Bowl" drought in Minnesota to investigate and quantify the impact of spatially coherent changes in lake area and volume on the land- atmosphere feedbacks that perpetuate drought conditions. A hypothetical lake-level change of 1m in all lakes (based on an observed behaviour of 1 to 5m of lake level change) yields an estimated change in sensible heating of 3 °C if the energy used to warm this total volume of water to 20 °C is instead used to warm a state- wide 1km tall column of air. It is compelling that this heuristic estimate of temperature change matches well with observed summer and fall temperature anomalies of 2-3 °C on a per climate division basis. To test and refine this result we generated a state wide map of lake area change from geo-referenced aerial photos taken at the end of the 1930's drought. The aerial response of over 500 small (accounting for .89 +/- .45 °C of the observed state-wide increase (decrease) in sensible heat in summer (winter) months. This calculated value compares favourably with the state-wide temperature anomalies observed between the dry late 1930's and wet intervals of the mid-forties, late-seventies and mid-nineties. A comparison of temperature anomalies between climate divisions with high and low percentages of lake area is also consistent with the above calculation, indicating that the calculated effect of surface water loss on

  7. NUMERICAL MODEL FOR FLOW THROUGH SUBMERGED VEGETATION REGIONS IN A SHALLOW LAKE*

    Institute of Scientific and Technical Information of China (English)

    WANG Pei-fang; WANG Chao

    2011-01-01

    Aquatic vegetation has a significant impact on water currents. To evaluate the effects of changes in the aquatic vegetation on water currents of different velocity, a 3-D hydrodynamic model was then developed by taking into consideration of the additional hydraulic resistance of the aquatic plants. The Navier- Stokes equations were then solved using the SIMPLE method and the k- ε turbulence model. Calculations using the established models were used to forecast the vertical distribution of the horizontal velocity and horizontal flow under the transmission conditions of the South-North Water Diversion in the Nansi Lake. And comparative calculation for the flow velocity was also performed using the simplified method of assigning a high roughness coefficient to the lake bed in the same area. Results suggest that adding additional hydraulic resistance of the aquatic plants is feasible. The calculation errors between simulation result and the field observed data are smaller than 15%, while, those errors are up to 35% if the influence of aquatic vegetation is dealt with the simplified method.

  8. Potential distribution of the viral haemorrhagic septicaemia virus in the Great Lakes region

    Science.gov (United States)

    Escobar, Luis E.; Kurath, Gael; Escobar-Dodero, Joaquim; Craft, Meggan E.; Phelps, Nicholas B.D.

    2017-01-01

    Viral haemorrhagic septicaemia virus (VHSV) genotype IVb has been responsible for large-scale fish mortality events in the Great Lakes of North America. Anticipating the areas of potential VHSV occurrence is key to designing epidemiological surveillance and disease prevention strategies in the Great Lakes basin. We explored the environmental features that could shape the distribution of VHSV, based on remote sensing and climate data via ecological niche modelling. Variables included temperature measured during the day and night, precipitation, vegetation, bathymetry, solar radiation and topographic wetness. VHSV occurrences were obtained from available reports of virus confirmation in laboratory facilities. We fit a Maxent model using VHSV-IVb reports and environmental variables under different parameterizations to identify the best model to determine potential VHSV occurrence based on environmental suitability. VHSV reports were generated from both passive and active surveillance. VHSV occurrences were most abundant near shore sites. We were, however, able to capture the environmental signature of VHSV based on the environmental variables employed in our model, allowing us to identify patterns of VHSV potential occurrence. Our findings suggest that VHSV is not at an ecological equilibrium and more areas could be affected, including areas not in close geographic proximity to past VHSV reports.

  9. Seismic reflection data from Lake Elsinore, Southern CA, reveal a sustained late-Holocene lake lowstand

    Science.gov (United States)

    Pyke, B. N.; Kirby, M. E.; Scholz, C. A.; Cattaneo, P.

    2009-12-01

    Lake Elsinore, located 120 kilometers southeast of Los Angeles, California, is Southern California’s largest natural lake. In December 2008, we collected over 75 km of high-resolution seismic reflection data using a CHIRP single-channel seismic-reflection Edgetech Geostar and the Geopulse™ Boomer systems. Initial interpretations reveal several interesting seismic sequences over the past 10,000 calendar years before present (cy BP: age control is based on dated sediment cores tied to the seismic lines). Most intriguing is evidence for a sustained interval of low lake level bracketed between ~ 3,000 and 1,800 cy BP. Prominent truncated stratal terminations characterize the upper boundary of this low stand seismic sequence. Sediment core data in the form of mudcracks, grain size variations, and geochemical data from various depositional environments (i.e., littoral and profundal) within Lake Elsinore support the seismic reflection interpretation for a low stand. Regionally, there is evidence for a similar interval of dry climate at Tulare Lake, the Mojave lakes, the Salton Sea, and possibly Dry Lake. A comparison to marine proxies along the eastern Pacific is less straight forward. The reason for this interval of sustained dry climate is not clear at this time. However, these results suggest that the already water-poor, over populated region of Southern California is subject to “droughts” of longer duration than that seen in the historical or tree-ring records from the region.

  10. Estimation of mercury emissions from forest fires, lakes, regional and local sources using measurements in Milwaukee and an inverse method

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2012-10-01

    Full Text Available Gaseous elemental mercury is a global pollutant that can lead to serious health concerns via deposition to the biosphere and bio-accumulation in the food chain. Hourly measurements between June 2004 and May 2005 in an urban site (Milwaukee, WI show elevated levels of mercury in the atmosphere with numerous short-lived peaks as well as longer-lived episodes. The measurements are analyzed with an inverse model to obtain information about mercury emissions. The model is based on high resolution meteorological simulations (WRF, hourly back-trajectories (WRF-FLEXPART and a chemical transport model (CAMx. The hybrid formulation combining back-trajectories and Eulerian simulations is used to identify potential source regions as well as the impacts of forest fires and lake surface emissions. Uncertainty bounds are estimated using a bootstrap method on the inversions. Comparison with the US Environmental Protection Agency's National Emission Inventory (NEI and Toxic Release Inventory (TRI shows that emissions from coal-fired power plants are properly characterized, but emissions from local urban sources, waste incineration and metal processing could be significantly under-estimated. Emissions from the lake surface and from forest fires were found to have significant impacts on mercury levels in Milwaukee, and to be underestimated by a factor of two or more.

  11. Identification of mercury emissions from forest fires, lakes, regional and local sources using measurements in Milwaukee and an inverse method

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2012-05-01

    Full Text Available Gaseous elemental mercury is a global pollutant that can lead to serious health concerns via deposition to the biosphere and bio-accumulation in the food chain. Hourly measurements between June 2004 and May 2005 in an urban site (Milwaukee, WI show elevated levels of mercury in the atmosphere with numerous short-lived peaks as well as longer-lived episodes. The measurements are analyzed with an inverse model to obtain information about mercury emissions. The model is based on high resolution meteorological simulations (WRF, hourly back-trajectories (WRF-FLEXPART and forward grid simulations (CAMx. The hybrid formulation combining back-trajectories and grid simulations is used to identify potential source regions as well as the impacts of forest fires and lake surface emissions. Uncertainty bounds are estimated using a bootstrap method on the inversions. Comparison with the US Environmental Protection Agency's National Emission Inventory (NEI and Toxic Release Inventory (TRI shows that emissions from coal-fired power plants are properly characterized, but emissions from local urban sources, waste incineration and metal processing could be significantly under-estimated. Emissions from the lake surface and from forest fires were found to have significant impacts on mercury levels in Milwaukee, and to be underestimated by a factor of two or more.

  12. DDT and HCH, two discontinued organochlorine insecticides in the Great Lakes region: isomer trends and sources.

    Science.gov (United States)

    Venier, Marta; Hites, Ronald A

    2014-08-01

    The uses of the insecticides 1,1'-(2,2,2-trichloroethylidene)bis[4-chlorobenzene] (p,p'-DDT) and γ-hexachlorocyclohexane (γ-HCH) have been discontinued for several years, but they are still consistently detected in air samples collected on the shores of the Great Lakes. Although the agricultural uses of DDT have been restricted in the United States since 1972, DDT continued to be used to manufacture the miticide, dicofol, up until 2011. The use of the technical HCH mixture in North America was restricted in the 1970s, when it was replaced by one of its purified conformers, γ-HCH, also known as lindane. In this study, we have focused on isomer-specific data to gain insights on the temporal trends and possible sources of these compounds. In particular, we calculated ratios of the concentrations of p,p'-DDE+p,p'-DDD versus the sum of the concentrations of the three p,p' isomers. These ratios are about the same at all five of our sampling sites and are about the same as observed globally. We also calculated the ratio of the concentrations of o,p'-DDT versus the sum of concentrations of o,p'-DDT+p,p'-DDT. This ratio has increased significantly at all five sites over the last 15-20 years. We suggest that dicofol, which contained about 11% o,p'-DDT, may now be a significant, additional source of DDT to the Great Lakes. The average ratio of the concentration of γ-HCH (lindane) versus the sum of the concentrations of γ-HCH+α-HCH did not vary significantly with time, but it did show an urban signature, suggesting that cities may be more important sources of these compounds than previously suspected.

  13. Modelling glacier-bed overdeepenings and possible future lakes for the glaciers in the Himalaya-Karakoram region

    DEFF Research Database (Denmark)

    Linsbauer, A.; Frey, H.; Haeberli, W.

    2016-01-01

    Surface digital elevation models (DEMs) and slope-related estimates of glacier thickness enable modelling of glacier-bed topographies over large ice-covered areas. Due to the erosive power of glaciers, such bed topographies can contain numerous overdeepenings, which when exposed following glacier...... stress as a function of elevation range for each glacier. The modelled ice thicknesses are uncertain (±30%), but spatial patterns of ice thickness and bed elevation primarily depend on surface slopes as derived from the DEM and, hence, are more robust. About 16 000 overdeepenings larger than 104m2 were...... retreat may fill with water and form new lakes. In this study, the bed overdeepenings for ∼28000 glaciers (40 775km2) of the Himalaya-Karakoram region are modelled using GlabTop2 (Glacier Bed Topography model version 2), in which ice thickness is inferred from surface slope by parameterizing basal shear...

  14. Nutritional Value and Consumption of Black Ants (Carebara vidua Smith from the Lake Victoria Region in Kenya

    Directory of Open Access Journals (Sweden)

    M.A. Ayieko

    2012-02-01

    Full Text Available The edible insects of the Lake Victoria region which provided food and medicine, have suffered the effects of mismanaged environment. Our case study of Carebara vidua Smith (black ant which is an endangered insect currently threatened with extinction due to human’s activities, have provided unique source of protein and medicinal value. C. vidua is an endangered species of Heminoptera. This paper discusses the nutritional value and medicinal potential of the black ant. It is one of the most sought after edible insects because of its nutritional and medicinal value. The samples were collected from Kisumu and Siaya counties along the Lake Victoria region. Standard nutrient analysis methods were used to determine the nutritional value. The insect has between 39.79 to 44.64% protein and about 42.07 to 49.77% fat content depending on the body part. The insect is also rich in iron, zinc, magnesium, potassium and phosphorus. From the fatty acid profile, the edible insects recorded high content of Palmitic, Oleic and Linoleic acids. No Linolenic acid was found in the samples analysed. The elderly Luos of Kenya collect and consume the black ants to manage several body ailments probably due to the essential nutrients found in the insect. C. vidua Smith is fairly similar to Polyrhachis vicina Roger in China which has been processed and commercialised as medicinal to manage several chronic diseases. Further research is needed to highlight the potential medicinal value of C. vidua Smith in Kenya and to save the insect from total disappearance.

  15. Soil phosphorus dynamic, balance and critical P values in long-term fertilization experiment in Taihu Lake region, China

    Institute of Scientific and Technical Information of China (English)

    SHI Lin-lin; SHEN Ming-xing; LU Chang-yin; WANG Hai-hou; ZHOU Xin-wei; JIN Mei-juan; WU Tong-dong

    2015-01-01

    Phosphorus (P) is an important macronutrient for plant but can also cause potential environmental risk. In this paper, we studied the long-term fertilizer experiment (started 1980) to assess the soil P dynamic, balance, critical P value and the crop yield response in Taihu Lake region, China. To avoid the effect of nitrogen (N) and potassium (K), only the folowing treatments were chosen for subsequent discussion, including: C0 (control treatment without any fertilizer or organic manure), CNK treatment (mineral N and K only), CNPK (balanced fertilization with mineral N, P and K), MNK (integrated organic ma-nure and mineral N and K), and MNPK (organic manure plus balanced fertilization). The results revealed that the response of wheat yield was more sensitive than rice, and no signiifcant differences of crop yield had been detected among MNK, CNPK and MNPK until 2013. Dynamic and balance of soil total P (TP) and Olsen-P showed soil TP pool was enlarged signiifcantly over consistent fertilization. However, the diminishing marginal utility of soil Olsen-P was also found, indicating that high-level P application in the present condition could not increase soil Olsen-P contents anymore. Linear-linear and Mitscherlich models were used to estimate the critical value of Olsen-P for crops. The average critical P value for rice and wheat was 3.40 and 4.08 mg kg–1, respectively. The smaler critical P value than in uplands indicated a stronger ability of P supply for crops in this paddy soil. We concluded that no more mineral P should be applied in rice-wheat system in Taihu Lake region if soil Olsen-P is higher than the critical P value. The agricultural technique and management referring to acti-vate the plant-available P pool are also considerable, such as integrated use of low-P organic manure with mineral N and K.

  16. Economic optimal nitrogen application rates for rice cropping in the Taihu Lake region of China: taking account of negative externalities

    Directory of Open Access Journals (Sweden)

    Y. Xia

    2011-07-01

    Full Text Available Nitrogen application rates (NARs is often overestimated over the rice (Oryza sativa L. growing season in the Taihu Lake region of China. This is largely because only individual nitrogen (N losses are taken into account, or the inventory flows of reactive N have been limited solely to the farming process when evaluating environmental and economic effects of N fertilizer. Since N can permeate the ecosystem in numerous forms commencing from the acquisition of raw material, through manufacturing and use, to final losses in the farming process (e.g., N2O, NH3, NO3 leaching, etc., the costs incurred also accumulate and should be taken into account if economically-optimal N rates (EONRs are to be established. This study integrates important material and energy flows resulting from N use into a rice agricultural inventory that constitutes the hub of the life-cycle assessment (LCA method. An economic evaluation is used to determine an environmental and economic NAR for the Taihu Lake region. The analysis reveals that production and exploitation processes consume the largest proportion of resources, accounting for 77.2 % and 22.3 % of total resources, respectively. Regarding environmental impact, global warming creates the highest cost with contributions stemming mostly from fertilizer production and raw material exploitation processes. Farming process incurs the biggest environmental impact of the three environmental impact categories considered, whereas transportation has a much smaller effect. When taking account of resource consumption and environmental cost, the marginal benefit of 1 kg rice would decrease from 2.4 to only 1.01 yuan. Accordingly, our current EONR has been evaluated at 185 kg N ha−1 for a single rice-growing season. This could enhance profitability, as well as reduce the N losses associated with rice growing.

  17. Identification of glacier motion and potentially dangerous glacial lakes in the Mt. Everest region/Nepal using spaceborne imagery

    Directory of Open Access Journals (Sweden)

    T. Bolch

    2008-12-01

    Full Text Available Failures of glacial lake dams can cause outburst floods and represents a serious hazard. The potential danger of outburst floods depends on various factors like the lake's area and volume, glacier change, morphometry of the glacier and its surrounding moraines and valley, and glacier velocity. Remote sensing offers an efficient tool for displacement calculations and risk assessment of the identification of potentially dangerous glacial lakes (PDGLs and is especially helpful for remote mountainous areas. Not all important parameters can, however, be obtained using spaceborne imagery. Additional interpretation by an expert is required. ASTER data has a suitable accuracy to calculate surface velocity. Ikonos data offers more detail but requires more effort for rectification. All investigated debris-covered glacier tongues show areas with no or very slow movement rates. From 1962 to 2003 the number and area of glacial lakes increased, dominated by the occurrence and almost linear areal expansion of the moraine-dammed lakes, like the Imja Lake. Although the Imja Lake will probably still grow in the near future, the risk of an outburst flood (GLOF is considered not higher than for other glacial lakes in the area. Potentially dangerous lakes and areas of lake development are identified. There is a high probability of further lake development at Khumbu Glacier, but a low one at Lhotse Glacier.

  18. FishVis, A regional decision support tool for identifying vulnerabilities of riverine habitat and fishes to climate change in the Great Lakes Region

    Science.gov (United States)

    Stewart, Jana S.; Covert, S. Alex; Estes, Nick J.; Westenbroek, Stephen M.; Krueger, Damon; Wieferich, Daniel J.; Slattery, Michael T.; Lyons, John D.; McKenna, James E.; Infante, Dana M.; Bruce, Jennifer L.

    2016-10-13

    Climate change is expected to alter the distributions and community composition of stream fishes in the Great Lakes region in the 21st century, in part as a result of altered hydrological systems (stream temperature, streamflow, and habitat). Resource managers need information and tools to understand where fish species and stream habitats are expected to change under future conditions. Fish sample collections and environmental variables from multiple sources across the United States Great Lakes Basin were integrated and used to develop empirical models to predict fish species occurrence under present-day climate conditions. Random Forests models were used to predict the probability of occurrence of 13 lotic fish species within each stream reach in the study area. Downscaled climate data from general circulation models were integrated with the fish species occurrence models to project fish species occurrence under future climate conditions. The 13 fish species represented three ecological guilds associated with water temperature (cold, cool, and warm), and the species were distributed in streams across the Great Lakes region. Vulnerability (loss of species) and opportunity (gain of species) scores were calculated for all stream reaches by evaluating changes in fish species occurrence from present-day to future climate conditions. The 13 fish species included 4 cold-water species, 5 cool-water species, and 4 warm-water species. Presently, the 4 cold-water species occupy from 15 percent (55,000 kilometers [km]) to 35 percent (130,000 km) of the total stream length (369,215 km) across the study area; the 5 cool-water species, from 9 percent (33,000 km) to 58 percent (215,000 km); and the 4 warm-water species, from 9 percent (33,000 km) to 38 percent (141,000 km).Fish models linked to projections from 13 downscaled climate models projected that in the mid to late 21st century (2046–65 and 2081–2100, respectively) habitats suitable for all 4 cold-water species and 4

  19. A new hydrogeological model of charging shallow and deep aquifers in the Lake Neusiedl - Seewinkel region (Northern Burgenland, Austria)

    Science.gov (United States)

    Häusler, Hermann; Müllegger, Christian; Körner, Wilfried; Ottner, Franz; Prohaska, Thomas; Irrgeher, Johanna; Tchaikovsky, Anastassiya; Dober, Gregor; Gritzmann, Romana; Mykhaylyuk, Ivanna

    2014-05-01

    .5‰ in the catchment of Lake Neusiedl are characteristic for waters derived from the cooler period of the Pleistocene (Rank et al., 1982), we conclude that groundwater of the deepest aquifer of the Seewinkel is not of Badenian to Sarmatian age but only several tens of thousands of years old. The artesian wells of the Seewinkel region drilled down to several hundreds of metres yielded groundwater with oxygen isotope ratio-values ranging between -11.90‰ and -10.83‰, values fitting well to waters of Pleistocene age of that region. Since wells discharging the Leitha Mountains also revealed oxygen isotope ratio-values varying from -11.10‰ to -10.22‰, we conclude that the mountain chains surrounding Lake Neusiedl basically charged both shallow and deeper aquifers of the Seewinkel. From oxygen isotope ratios of these groundwater bodies we therefore conclude that first the majority of aquifers of the Lake Neusiedl region was charged from the surrounding mountain chains, and second that salinity of soils in the Seewinkel region cannot be derived from up welling connate water, as has been proofed for Lake Kelemenszék area south of Budapest (Simon et al., 2011). There is no doubt on the fact, however, that differing amounts of free carbon dioxide in several aquifers of the Seewinkel region originate from deep-seated post volcanic activity in this region. Häusler, H. (2010)(ed.): Geologische Karte der Republik Österreich 1:50.000, Erläuterungen zur Geologischen Karte 78 Rust.- 191 S., 65 Abb., 5 Tab., 2 Taf., (Geologische Bundesanstalt), Wien. Rank, D., Rajner, V., Staudner, F. and Papesch, W. (1982): Zur Altersdatierung der Grundwässer am Ostufer des Neusiedlersees.- BFB-Bericht, 43, 197-204, 2 Abb., (Biologisches Forschungsinstitut für Burgenland), Illmitz. Simon, S., Mádl-Szőnyi, J., Müller, I. and Pogácsás, G. (2011): Conceptual model for surface salinization in an overpressured and a superimposed gravity-flow field, Lake Kelemenszék area, Hungary

  20. Hydroclimatology of Lake Victoria region using hydrologic model and satellite remote sensing data

    Directory of Open Access Journals (Sweden)

    S. I. Khan

    2011-01-01

    Full Text Available Study of hydro-climatology at a range of temporal scales is important in understanding and ultimately mitigating the potential severe impacts of hydrological extreme events such as floods and droughts. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10- year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia basin. The spatiotemporal variability of the water cycle components were quantified using a hydrologic model, with in-situ and multi-satellite remote sensing datasets. The model is calibrated using daily observed discharge data for the period between 1985 and 1999, for which model performance is estimated with a Nash Sutcliffe Efficiency (NSCE of 0.87 and 0.23% bias. The model validation showed an error metrics with NSCE of 0.65 and 1.04% bias. Moreover, the hydrologic capability of satellite precipitation (TRMM-3B42 V6 is evaluated. In terms of reconstruction of the water cycle components the spatial distribution and time series of modeling results for precipitation and runoff showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to

  1. Best Practices for Sustainable WInd Energy Development in the Great Lakes Region and Beyond

    Energy Technology Data Exchange (ETDEWEB)

    Great Lakes Commission; Victoria Pebbles; John Hummer; Celia Haven

    2011-07-19

    This document offers a menu of 18 different, yet complimentary preferred practices and policies. The best practices cover all phases of the wind energy development process - from the policies that allow for wind development, to the sustainable operation of a wind project, to the best practices for decommissioning a spent turbine - including applications for offshore wind. The practices include those that have been previously tested and proven effective, as well as new practices that were identified by experts in the field as needed for future wind developments. Each best practice includes information about the opportunities and challenges (pros and cons), and offers a case example that illustrates how that best practice is being utilized by a particular jurisdiction or wind project. The practices described in this publication were selected by a diverse group of interests from the Great Lakes Wind Collaborative that included environmental groups, industry, and federal, state and local government regulators. They were identified through a year long process that included a literature review, online survey and interviews with individuals from the public, private and non-profit sectors.

  2. Late Cretaceous intraplate silicic volcanic rocks from the Lake Chad region: An extension of the Cameroon volcanic line?

    Science.gov (United States)

    Shellnutt, J. G.; Lee, T.-Y.; Torng, P.-K.; Yang, C.-C.; Lee, Y.-H.

    2016-07-01

    Silicic volcanic rocks at Hadjer el Khamis, near Lake Chad, are considered to be an extension of the Cameroon volcanic line (CVL) but their petrogenetic association is uncertain. The silicic rocks are divided into peraluminous and peralkaline groups with both rock types chemically similar to within-plate granitoids. In situ U/Pb zircon dating yielded a mean 206Pb/238U age of 74.4 ± 1.3 Ma indicating the magmas erupted ˜10 million years before the next oldest CVL rocks (i.e., ˜66 Ma). The Sr isotopes (i.e., ISr = 0.7021-0.7037) show a relatively wide range but the Nd isotopes (i.e., 143Nd/144Ndi = 0.51268-0.51271) are uniform and indicate that the rocks were derived from a moderately depleted mantle source. Thermodynamic modeling shows that the silicic rocks likely formed by fractional crystallization of a mafic parental magma but that the peraluminous rocks were affected by low temperature alteration processes. The silicic rocks are more isotopically similar to Late Cretaceous basalts identified within the Late Cretaceous basins (i.e., 143Nd/144Ndi = 0.51245-0.51285) of Chad than the uncontaminated CVL rocks (i.e., 143Nd/144Ndi = 0.51270-0.51300). The age and isotopic compositions suggest the silicic volcanic rocks of the Lake Chad region are related to Late Cretaceous extensional volcanism in the Termit basin. It is unlikely that the silicic volcanic rocks are petrogenetically related to the CVL but it is possible that magmatism was structurally controlled by suture zones that formed during the opening of the Central Atlantic Ocean and/or the Pan-African Orogeny.

  3. Modelling regional response of lakewater chemistry to changes in acidic deposition: the MAGIC model applied to lake surveys in southernmost Norway 1974-1986-1995

    Directory of Open Access Journals (Sweden)

    B. J. Cosby

    1998-01-01

    Full Text Available Two methods for modelling regional responses of lake water quality to changes in acidic deposition in southernmost Norway were examined. Both methods are based upon the MAGIC model but differ in mode of regional application; one uses site-specific while the other uses Monte-Carlo methods for model calibration. The simulations of regional responses from both methods were compared with observed responses based on data from three lake surveys in southernmost Norway conducted in 1974, 1986 and 1995. The regional responses of the two modelling approaches were quite similar and agreed well with the observed regional distributions of lakewater chemistry variables. From 1974 to 1986 the observed data indicated that despite a decline of approximately 10% in sulphate (SO4 deposition, the mean acid neutralizing capacity (ANC of lakes in southernmost Norway declined by approximately 6 μeq l-1. Both modelling approaches simulated no change or a very small decline in mean ANC for that period. From 1986 to 1995 the observed data indicated that, in response to an approximate 40% decline in SO4 deposition, the mean ANC of lakes in southernmost Norway increased by 11-16 μeq l-1. The modelling approaches simulated increases of 9-10 μeq l-1 in mean ANC for the same period. Both simulations and observations indicate that > 65% of lakes in southernmost Norway were acidic in 1974 and 1995. Both simulation methods predict that >65% of the lakes in southernmost Norway will have positive ANC values within 10 years of reductions of SO4 deposition to 20% of 1974 levels. Of the two regionalization methods the site-specific method appears preferable, because whereas the Monte-Carlo method gives results for a region as a whole, the site-specific method also reveals patterns within the region. The maintenance of a one-to-one correspondence between simulated and observed systems means that simulation results can be mapped for a geographically explicit presentation of model

  4. Characteristics Of Atmospheric Dry Deposition Of Metals To The Region Of Lake Asan And Sapgyo, Korea

    Science.gov (United States)

    Han, J.; Shin, H.; Lee, M.; Lim, Y.; Seo, M.; Jung, I.

    2008-12-01

    Environment includes a multi-media such as air, surface water, soil, underground water and ecosystem. Some pollutants transfer among a multi-media, posing serious threat to humans, animals and plants. Pollutants released into the environment remain for long times and transport long distances while going through physical and chemical interactions such as transports between multi-media ; air, water and soil, deposition, and absorption and release from organisms. This study assessed the amount of heavy metals transferred from air to water and soil using dry deposition plate and water surface sampler during spring (June 13 ~ 21, 2007) and winter (October 23 ~ 30 in 2007) at 9 locations including Dangjin, Pyeongtaek and Asan. Micro-Orifice Uniform Deposit Impactor, MOUDI was used to confirm the size distribution. The measured heavy metal deposition flux was compared with the expectation obtained with deposition model. In addition, amount of heavy metal deposition at Asan and Sapgyo lakes were evaluated to verify the water pollution state driven by atmospheric deposition. Atmospheric dry deposition flux of metals are 133.92 microgram m-2 day-1, 44.01 microgram m-2 day-1, 0.915 microgram m-2 day-1, and 0.175 microgram m-2 day-1 during spring, and 72.86 microgram m-2 day- 1, 88.14 microgram m-2 day-1, 0.991 microgram m-2 day-1, and 0.189 microgram m-2 day-1 during fall, for lead, nickel, arsenic, and cadmium, respectively. It is required to re- calculation the dry deposition flux by land use type due to possibility of underestimating the flux in case of using grease surrogate surface having low surface roughness. The cadmium, lead, and arsenic size distribution was mono-modal with the peaks in the 0.65 ~ 1.1 micrometer size range in the fine mode showing sharp peak in the condensation submode especially for cadmium and lead because of effect of primary emission. The nickel size distribution was bimodal, a typical size distribution for an urban atmosphere, showing sharp

  5. Distribution and Fate of Black Carbon Nanoparticles from Regional Urban Pollution and Wildfire at a Large Subalpine Lake in the Western United States

    Science.gov (United States)

    Bisiaux, M. M.; Heyvaert, A. C.; Edwards, R.

    2012-04-01

    Emitted to the atmosphere through fire and fossil fuel combustion, refractory black carbon nanoparticles (rBC) impact human health, climate, atmospheric chemistry, and the carbon cycle. Eventually these particles enter aquatic environments, where their distribution, fate and association with other pollutants are still poorly characterized. This study presents results from an evaluation of rBC in the waters of oligotrophic Lake Tahoe and its watershed in the western United States. The study period included a large wildfire within the Tahoe basin, seasonal snowmelt, and a number of storm events that resulted in pulsed urban runoff into the lake with rBC concentrations up to four orders of magnitude higher than mid-lake concentrations. The results show that elevated rBC concentrations from wildfire and urban runoff were rapidly attenuated in the lake, suggesting unexpected aggregation or degradation of the particles that prevent rBC concentrations from building up in the water of this lake, renowned for its clarity. The rBC concentrations were also measured in sediment cores from Lake Tahoe to evaluate the sediment archive as a potential combustion record. The evidence suggests that rBC is efficiently transferred to these sediments, which preserve a local-to-regional scale history of rBC emissions, as revealed by comparison with other pollutant records in the sediment. Rapid removal of rBC soon after entry into the lake has implications for transport of rBC in the global aquatic environment and flux of rBC from continents to the global ocean.

  6. Maintaining yields and reducing nitrogen loss in rice-wheat rotation system in Taihu Lake region with proper fertilizer management

    Science.gov (United States)

    Xue, Lihong; Yu, Yingliang; Yang, Linzhang

    2014-11-01

    In the Tailake region of China, heavy nitrogen (N) loss of rice-wheat rotation systems, due to high fertilizer-N input with low N use efficiency (NUE), was widely reported. To alleviate the detrimental impacts caused by N loss, it is necessary to improve the fertilizer management practices. Therefore, a 3 yr field experiments with different N managements including organic combined chemical N treatment (OCN, 390 kg N ha-1 yr-1, 20% organic fertilizer), control-released urea treatment (CRU, 390 kg N ha-1 yr-1, 70% resin-coated urea), reduced chemical N treatment (RCN, 390 kg N ha-1 yr-1, all common chemical fertilizer), and site-specific N management (SSNM, 333 kg N ha-1 yr-1, all common chemical fertilizer) were conducted in the Taihu Lake region with the ‘farmer’s N’ treatment (FN, 510 kg N ha-1 yr-1, all common chemical fertilizer) as a control. Grain yield, plant N uptake (PNU), NUE, and N losses via runoff, leaching, and ammonia volatilization were assessed. In the rice season, the FN treatment had the highest N loss and lowest NUE, which can be attributed to an excessive rate of N application. Treatments of OCN and RCN with a 22% reduced N rate from FN had no significant effect on PNU nor the yield of rice in the 3 yr; however, the NUE was improved and N loss was reduced 20-32%. OCN treatment achieved the highest yield, while SSNM has the lowest N loss and highest NUE due to the lowest N rate. In wheat season, N loss decreased about 28-48% with the continuous reduction of N input, but the yield also declined, with the exception of OCN treatment. N loss through runoff, leaching and ammonia volatilization was positively correlated with the N input rate. When compared with the pure chemical fertilizer treatment of RCN under the same N input, OCN treatment has better NUE, better yield, and lower N loss. 70% of the urea replaced with resin-coated urea had no significant effect on yield and NUE improvement, but decreased the ammonia volatilization loss. Soil

  7. Critical loads of acidity for 90,000 lakes in northern Saskatchewan: A novel approach for mapping regional sensitivity to acidic deposition

    Science.gov (United States)

    Cathcart, H.; Aherne, J.; Jeffries, D. S.; Scott, K. A.

    2016-12-01

    Atmospheric emissions of sulphur dioxide (SO2) from large point sources are the primary concern for acidic deposition in western Canada, particularly in the Athabasca Oil Sands Region (AOSR) where prevailing winds may potentially carry SO2 over acid-sensitive lakes in northern Saskatchewan. A novel catchment-scale regression kriging approach was used to assess regional sensitivity and critical loads of acidity for the total lake population of northern Saskatchewan (89,947 lakes). Lake catchments were delineated using Thiessen polygons, and surface water chemistry was predicted for sensitivity indicators (calcium, pH, alkalinity, and acid neutralizing capacity). Critical loads were calculated with the steady state water chemistry model using regression-kriged base cations, sulphate, and dissolved organic carbon concentrations modelled from surface water observations (n > 800) and digital landscape-scale characteristics, e.g., climate, soil, vegetation, landcover, and geology maps. A large region (>13,726 km2) of two or more indicators of acid sensitivity (pH acid neutralizing capacity, alkalinity, calcium acidic deposition in excess of their critical loads and many of them may be at risk of ecosystem damage owing to their sensitivity.

  8. Characterization of a novel hepadnavirus in the white sucker (Catostomus commersonii) from the Great Lakes Region of the USA

    Science.gov (United States)

    Hahn, Cassidy M.; Iwanowicz, Luke R.; Cornman, Robert S.; Conway, Carla M.; Winton, James R.; Blazer, Vicki S.

    2015-01-01

    The white sucker Catostomus commersonii is a freshwater teleost often utilized as a resident sentinel. Here, we sequenced the full genome of a hepatitis B-like virus that infects white suckers from the Great Lakes Region of the USA. Dideoxysequencing confirmed the white sucker hepatitis B virus (WSHBV) has a circular genome (3542 bp) with the prototypical codon organization of hepadnaviruses. Electron microscopy demonstrated that complete virions of approximately 40 nm were present in the plasma of infected fish. Compared to avi- and orthohepadnaviruses, sequence conservation of the core, polymerase and surface proteins was low and ranged from 16-27% at the amino acid level. An X protein homologue common to the orthohepadnaviruses was not present. The WSHBV genome included an atypical, presumptively non-coding region absent in previously described hepadnaviruses. Phylogenetic analyses confirmed WSHBV as distinct from previously documented hepadnaviruses. The level of divergence in protein sequences between WSHBV other hepadnaviruses, and the identification of an HBV-like sequence in an African cichlid provide evidence that a novel genus of the family Hepadnaviridae may need to be established that includes these hepatitis B-like viruses in fishes. Viral transcription was observed in 9.5% (16 of 169) of white suckers evaluated. The prevalence of hepatic tumors in these fish was 4.9%, of which only 2.4% were positive for both virus and hepatic tumors. These results are not sufficient to draw inferences regarding the association of WSHBV and carcinogenesis in white sucker.

  9. Evaluation of recent trends of sedimentation in Indian lakes of western Himalayan region using {sup 210}Pb and {sup 137}Cs dating techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, B.; Rai, S.P.; Nachippan, R.P. [National Institute of Hydrology, UA (India)

    2004-07-01

    In the present study, environmental {sup 210}Pb and {sup 137}Cs dating techniques were employed to determine the recent sedimentation rates of Nainital, Bhimtal, Sat-tal, Naukuchiyatal and Mansar and Dal-Nagin lake of Western Himalayan region. The expected useful life of these lakes have also been estimated. These studies are part of the project funded by Government of India. Three to five sediment cores were collected from the each lakes namely Nainital, Bhimtal, Naukuchiyatal, Sat-tal and Mansar and 14 sediment cores from Dal-Nagin lake using a gravity corer. The sediment cores ranging from 19 to 53 cm in length were sliced at 2 cm intervals. Sliced core sections were brought to laboratory and subjected to various physical and chemical process before measuring {sup 137}Cs and {sup 210}Pb activities. After the chemical treatment of the sliced samples, the extracted solution containing {sup 210}Pb was allowed to stay for a period of one month as 4 to 5 half lives are sufficient for this purpose for getting {sup 210}Bi in secular equilibrium with {sup 210}Pb activity. The {sup 210}Pb activity was measured in terms of beta radiations using {sup 210}Bi which is its daughter product and has half life of {approx}5 days. The activity of {sup 210}Bi was measured using a Ultra Low level Liquid Scintillation spectrometer and CRS model was applied for estimating rates of sedimentation. The {sup 137}Cs activity in each section was determined by gamma counting in the oven-dried samples using Hyper Pure Germanium detector coupled with a 4096 channel multichannel analyser system. A {sup 137}Cs standard, having essentially the same geometry and density was used. The detection limit for {sup 137}Cs by this method is 0.25 mBq.g{sup -1} and the standard counting error was less than 10% in the core sections. The sedimentation rate varies between 1.74 cm/yr to 3.87 cm/yr (weighted mean 1.44 {+-} 0.18 cm/y) in Bhimtal lake, 0.38 cm/yr to 0.95 cm/yr (weighted mean 0.74 {+-} 0.04 cm

  10. Factors Affecting Elevated Arsenic and Methyl Mercury Concentrations in Small Shield Lakes Surrounding Gold Mines near the Yellowknife, NT, (Canada Region.

    Directory of Open Access Journals (Sweden)

    Adam James Houben

    Full Text Available Gold mines in the Yellowknife, NT, region--in particular, the Giant Mine--operated from 1949-99, releasing 237,000 tonnes of waste arsenic trioxide (As2O3 dust, among other compounds, from gold ore extraction and roasting processes. For the first time, we show the geospatial distribution of roaster-derived emissions of several chemical species beyond the mine property on otherwise undisturbed taiga shield lakes within a 25 km radius of the mine, 11 years after its closing. Additionally, we demonstrate that underlying bedrock is not a significant source for the elevated concentrations in overlying surface waters. Aquatic arsenic (As concentrations are well above guidelines for drinking water (10 μg/L and protection for aquatic life (5 μg/L, ranging up to 136 μg/L in lakes within 4 km from the mine, to 2.0 μg/L in lakes 24 km away. High conversion ratios of methyl mercury were shown in lakes near the roaster stack as well, with MeHg concentrations reaching 44% of total mercury. The risk of elevated exposures by these metals is significant, as many lakes used for recreation and fishing near the City of Yellowknife are within this radius of elevated As and methyl Hg concentrations.

  11. Factors Affecting Elevated Arsenic and Methyl Mercury Concentrations in Small Shield Lakes Surrounding Gold Mines near the Yellowknife, NT, (Canada) Region.

    Science.gov (United States)

    Houben, Adam James; D'Onofrio, Rebecca; Kokelj, Steven V; Blais, Jules M

    2016-01-01

    Gold mines in the Yellowknife, NT, region--in particular, the Giant Mine--operated from 1949-99, releasing 237,000 tonnes of waste arsenic trioxide (As2O3) dust, among other compounds, from gold ore extraction and roasting processes. For the first time, we show the geospatial distribution of roaster-derived emissions of several chemical species beyond the mine property on otherwise undisturbed taiga shield lakes within a 25 km radius of the mine, 11 years after its closing. Additionally, we demonstrate that underlying bedrock is not a significant source for the elevated concentrations in overlying surface waters. Aquatic arsenic (As) concentrations are well above guidelines for drinking water (10 μg/L) and protection for aquatic life (5 μg/L), ranging up to 136 μg/L in lakes within 4 km from the mine, to 2.0 μg/L in lakes 24 km away. High conversion ratios of methyl mercury were shown in lakes near the roaster stack as well, with MeHg concentrations reaching 44% of total mercury. The risk of elevated exposures by these metals is significant, as many lakes used for recreation and fishing near the City of Yellowknife are within this radius of elevated As and methyl Hg concentrations.

  12. Climate change impacts on soil erosion in the Great Lakes Region

    Science.gov (United States)

    Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, especially for regions dominated by agricultural land use, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting ...

  13. Late Glacial and Holocene environmental history of Wielkopolska region (western Poland) recorded in sediments of Strzeszyńskie Lake and Kierskie Lake

    Science.gov (United States)

    Pleskot, Krzysztof; Szczuciński, Witold; Tjallingii, Rik; Makohonienko, Mirosław; Nowaczyk, Norbert; Brauer, Achim

    2016-04-01

    The growing amount of publications concerning reconstructions of Late Glacial and Holocene environment based on analysis of lake sediments gives us robust insight into general patterns of that record. However, it is still challenging to decipher processes and events that occurred on local scale, as they record may be strongly affected by the type, catchment, size and depth of a lake. Therefore in the present study we focus on application of sedimentological and geochemical methods in order to reveal environmental history from two neighbouring lakes located within city of Poznań, Wielkopolska (western Poland). The lake sediments analysis cover Late Glacial and Holocene in case of smaller Strzeszyńskie Lake (SL) and the last 8 ka in deeper Kierskie Lake (KL). The study is based on two 8.5 (SL) and 14 (KL) m long sediment cores, which were described and analyzed in thin sections and on smear slides. The relative chemical composition variations within the cores were measured using an X-ray fluorescence (XRF). Moreover, the cores were measured for magnetic susceptibility and sampled for pollen analysis. The chronology has been established by a AMS 14C dating of bulk samples of lake sediments. To assess the reservoir effect, selected samples were analyzed for soluble and residual carbon fractions. Our results suggest the onset of authigenic sedimentation in SL in Allerød. The sediments from this period are characterized by high organic matter and low carbonate content. This trend changed into opposite at the beginning of the Younger Dryas, while at its termination sediments again became more organic. The transition to Holocene is marked by spread of Betula forest, gradual increase in magnetic susceptibility and Ca content together with decreasing organic matter and clastic input. During Preboreal and Boreal period the relatively stable conditions was noted. Then, ca. 8.5 ka BP, sharp decrease in magnetic susceptibility occurred coincided with deciduous forest

  14. Post-glacial recolonization of the Great Lakes region by the common gartersnake (Thamnophis sirtalis) inferred from mtDNA sequences.

    Science.gov (United States)

    Placyk, John S; Burghardt, Gordon M; Small, Randall L; King, Richard B; Casper, Gary S; Robinson, Jace W

    2007-05-01

    Pleistocene events played an important role in the differentiation of North American vertebrate populations. Michigan, in particular, and the Great Lakes region, in general, were greatly influenced by the last glaciation. While several hypotheses regarding the recolonization of this region have been advanced, none have been strongly supported. We generated 148 complete ND2 mitochondrial DNA (mtDNA) sequences from common gartersnake (Thamnophis sirtalis) populations throughout the Great Lakes region to evaluate phylogeographic patterns and population structure and to determine whether the distribution of haplotypic variants is related to the post-Pleistocene retreat of the Wisconsinan glacier. The common gartersnake was utilized, as it is believed to have been one of the primary vertebrate invaders of the Great Lakes region following the most recent period of glacial retreat and because it has been a model species for a variety of evolutionary, ecological, behavioral, and physiological studies. Several genetically distinct evolutionary lineages were supported by both genealogical and molecular population genetic analyses, although to different degrees. The geographic distribution of the majority of these lineages is interpreted as reflecting post-glacial recolonization dynamics during the late Pleistocene. These findings generally support previous hypotheses of range expansion in this region.

  15. Simulation of wind-driven circulation and temperature in the near-shore region of southern Lake Michigan by using a channelized model

    Institute of Scientific and Technical Information of China (English)

    LIU Lubo; FU Xu-dong; WANG Guang-qian

    2013-01-01

    To enhance the efficiency of a pathogen forecasting model in the beach areas of southern Lake Michigan and to reduce the computation time,the near-shore current is approximated as a channelized flow parallel to the shorelines in clockwise or anti-clockwise direction within the accuracy tolerance range.A channelized model with a curvilinear boundary can significantly reduce the computation effort,and at the same time achieve a good agreement between the predicted and measured water surface elevations,currents,and water temperatures.The sensitivity analysis results show that the suitable channel width for the near-shore region of southern Lake Michigan should be no less than 10 km.The modeling results of the water temperature are much less sensitive to the channel width than those of the current velocity and the water surface elevation.The modeling results also show a close correlation between the speeds of the wind and the near-shore current.The current may fully respond the wind stress with a time lag of several hours.The correlation may provide an approximate estimation of the lake circulation under some wind conditions for a practical forecasting purpose.More complex wind-current relationships need to be described with a more sophisticated hydrodynamic model.This verified model can be used for the pathogen forecasting in the near-shore regions of southern Lake Michigan in the future.

  16. Regional-scale GIS-models for assessment of hazards from glacier lake outbursts: evaluation and application in the Swiss Alps

    Directory of Open Access Journals (Sweden)

    C. Huggel

    2003-01-01

    Full Text Available Debris flows triggered by glacier lake outbursts have repeatedly caused disasters in various high-mountain regions of the world. Accelerated change of glacial and periglacial environments due to atmospheric warming and increased anthropogenic development in most of these areas raise the need for an adequate hazard assessment and corresponding modelling. The purpose of this paper is to pro-vide a modelling approach which takes into account the current evolution of the glacial environment and satisfies a robust first-order assessment of hazards from glacier-lake outbursts. Two topography-based GIS-models simulating debris flows related to outbursts from glacier lakes are presented and applied for two lake outburst events in the southern Swiss Alps. The models are based on information about glacier lakes derived from remote sensing data, and on digital elevation models (DEM. Hydrological flow routing is used to simulate the debris flow resulting from the lake outburst. Thereby, a multiple- and a single-flow-direction approach are applied. Debris-flow propagation is given in probability-related values indicating the hazard potential of a certain location. The debris flow runout distance is calculated on the basis of empirical data on average slope trajectory. The results show that the multiple-flow-direction approach generally yields a more detailed propagation. The single-flow-direction approach, however, is more robust against DEM artifacts and, hence, more suited for process automation. The model is tested with three differently generated DEMs (including aero-photogrammetry- and satellite image-derived. Potential application of the respective DEMs is discussed with a special focus on satellite-derived DEMs for use in remote high-mountain areas.

  17. Invasion of Nostocales (cyanobacteria to subtropical and temperate freshwater lakes – Physiological, regional and global driving forces

    Directory of Open Access Journals (Sweden)

    Assaf eSukenik

    2012-03-01

    Full Text Available Similarly to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases regional changes in nutrient loads and in biotic conditions were attributed to the invasion events

  18. Ammonia Volatilization and Nitrogen Utilization Efficiency in Response to Urea Application in Rice Fields of the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 (control), 100, 200, 300, or 350 kg N ha-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates (300 and 350 kg N ha-1) showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice.

  19. Clear cell chondrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R.; David, R.; Cierney, G. III

    1985-01-01

    The clinical, radiologic, and histopathologic features of three cases of clear cell chondrosarcoma are described. On radiographs, this rather benign-appearing tumor resembles a chondroblastoma when it occurs at the end of a long bone, and may occasionally show a calcified matrix. However, it has distinctive tumor cells with a centrally placed vesicular nucleus surrounded by clear cytoplasm. The lesion has a low-grade malignancy and is amenable to en bloc surgical resection, which results in a much better prognosis than that of conventional chondrosarcoma.

  20. A GIS method for assessment of rock slide tsunami hazard in all Norwegian lakes and reservoirs

    Directory of Open Access Journals (Sweden)

    B. Romstad

    2009-03-01

    Full Text Available An evaluation of rock slide tsunami hazard is applied to all Norwegian lakes larger than 0.1 km2 based on their topographical setting. The analysis results in a topographic rock slide potential score that indicates the relative hazard in each lake. Even though the score value each lake receives should be interpreted with caution, the distribution of score values shows that we are able to make a clear distinction between lakes with a high vs. lakes with a low hazard. The results also show a clustering of threatened lakes in parts of Western Norway as well as some locations in Northern Norway. This makes the results useful as a tool for focusing further studies on regions or specific lakes that received high scores. The results also show how the method may be used for more detailed analysis of a given lake (or fjord. Maps can be produced that may serve as a guide when carrying out field campaigns or when designing scenarios for numerical simulations of tsunamis in the lake. It should be emphasised that the rock slide potential reported for each lake is based on the topographical setting alone and hence, does not represent the actual probability of rock slides into the lakes. For a given area, more detailed investigations of the geology, triggering factors and frequency of previous rock slide events should be carried out before definite statements about the actual hazard can be made.

  1. GRACE water storage estimates for the Middle East and other regions with significant reservoir and lake storage

    Directory of Open Access Journals (Sweden)

    L. Longuevergne

    2012-10-01

    Full Text Available While GRACE (Gravity Recovery and Climate Experiment satellites are increasingly being used to monitor water storage changes globally, the impact of spatial distribution of water storage within a basin is generally ignored but may be substantial. In many basins, water may be stored in reservoirs, lakes, flooded areas, small aquifer systems, and other localized regions with sizes typically below GRACE resolution. The objective of this study was to assess the impact of non-uniform water storage distribution on GRACE estimates as basin-wide averages, focusing on surface water reservoirs. Analysis included numerical experiments testing the effect of mass size and position within a basin, and application to the Lower Nile (Lake Nasser and Tigri–Euphrates (TE basins as examples. Numerical experiments show that by assuming uniform mass distribution, GRACE estimates may under- or over-estimate basin-average water storage by up to a factor of two, depending on reservoir location and extent. Although their spatial extent may be unresolved by GRACE, reservoir storage may dominate in some basins. For example, it accounts for 95% of seasonal variations in the Lower Nile and 10% in the TE basins. Because reservoirs are used to mitigate droughts and buffer against climate extremes, their influence on interannual time scales can be large, for example accounting for 50% of total water storage decline during the 2007–2009 drought in the TE basin. Effects on GRACE estimates are not easily accounted for via simple multiplicative scaling, but in many cases independent information may be available to improve estimates. Accurate estimation of the reservoir contribution is critical, especially when separating groundwater from GRACE total water storage changes. Because the influence of spatially concentrated water storage – and more generally water distribution – is significant, GRACE estimates will be improved when it is possible to combine independent spatial

  2. Snow-clearing operations

    CERN Document Server

    EN Department

    2010-01-01

    To facilitate snow clearing operations, which commence at 4.30 in the morning, all drivers of CERN cars are kindly requested to park them together in groups. This will help us greatly assist us in our work. Thank-you for your help. Transport Group / EN-HE Tel. 72202

  3. Social-Ecological Thresholds in a Changing Boreal Landscape: Insights from Cree Knowledge of the Lesser Slave Lake Region of Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Brenda L. Parlee

    2012-06-01

    Full Text Available Drawing on the traditional ecological knowledge (TEK of the Lesser Slave Lake Cree, this paper shares understanding of how resource development has affected water, fish, forests, and wildlife as well as the well-being of Cree communities in the Lesser Slave Lake region of Alberta, Canada. In addition to descriptive observations of change, the narratives point to social-ecological thresholds or tipping points in the relationship of Cree harvesters to local lands and resources. Specifically, the study speaks to the echoing effects of ecological loss and degradation on traditional livelihood practices over the last 100 years highlighting the complexity of cumulative effects as well as the challenges of balancing resource development in the region with alternative land uses including those valued by Alberta's Aboriginal peoples.

  4. Historical trophic evolutions and their ecological responses from shallow lakes in the middle and lower reaches of the Yangtze River: Case studies on Longgan Lake and Taibai Lake

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The evolutions of diatom floras and the total phosphorous (TP) concentrations in the historical period were reconstructed for two lakes, Longgan and Taibai in the middle Yangtze River,based on high resolutional fossil diatom study from two sediment cores and an established regional diatom-TP transfer function. The TP concentration in Longgan Lake changed slightly in the range of 36-62 μg/L and kept its middle trophic level in the past 200 years. The changes of diatom assemblages reflect a macrophyte-dominated history of the lake. During the nineteenth century, the lake TP concentration increased comparatively, corresponding to the increase in abundance of benthic diatoms. The progressive increase of epiphytic diatoms since the onset of the twentieth century indicates the development of aquatic plants, coinciding with the twice drops of water TP level. The TP concentration in Taibai Lake kept a stable status about 50 μg/L before 1953 AD, while diatoms dominated by facultative planktonic Aulacoseira granulata shifted quickly to epiphytic diatom species, indicating a rapid expansion of aquatic vegetation. During 1953-1970 AD, the coverage of aquatic plants decreased greatly inferred by the low abundance of epiphytic diatoms as well as declined planktonic types, and the reconstructed TP concentration shows an obvious rising trend firstly, suggesting the beginning of the lake eutrophication. The lake was in the eutrophic condition after 1970, coinciding with the successive increase of planktonic diatoms. The comparison of the two lakes suggests the internal adjustment and purification function of aquatic plants for nutrients in water. The discrepancy of TP trends in the two lakes after 1960 reflects two different patterns of lake environmental response to human disturbance. Sediments in Taibai Lake clearly recorded the process of lake ecological transformation from the macrophyte-dominated stage to the algae-dominated stage. The limits of TP concentration (68-118

  5. Patterns of Dekadal Rainfall Variation Over a Selected Region in Lake Victoria Basin, Uganda

    Directory of Open Access Journals (Sweden)

    Isaac Mugume

    2016-11-01

    Full Text Available Understanding variations in rainfall in tropical regions is important due to its impacts on water resources, health and agriculture. This study assessed the dekadal rainfall patterns and rain days to determine intra-seasonal rainfall variability during the March–May season using the Mann–Kendall ( M K trend test and simple linear regression ( S L R over the period 2000–2015. Results showed an increasing trend of both dekadal rainfall amount and rain days (third and seventh dekads. The light rain days ( S L R = 0.181; M K = 0.350 and wet days ( S L R = 0.092; M K = 0.118 also depict an increasing trend. The rate of increase of light rain days and wet days during the third dekad (light rain days: S L R = 0.020; M K = 0.279 and wet days: S L R = 0.146; M K = 0.376 was slightly greater than during the seventh dekad (light rain days: S L R = 0.014; M K = 0.018 and wet days: S L R = 0.061; M K = 0.315 dekad. Seventy-four percent accounted for 2–4 consecutive dry days, but no significant trend was detected. The extreme rainfall was increasing over the third ( M K = 0.363 and seventh ( M K = 0.429 dekads. The rainfall amount and rain days were highly correlated (r: 0.43–0.72.

  6. The state and their implication of Himalayan glacial lake changes from satellite observations

    Science.gov (United States)

    Nie, Y.; Sheng, Y.; Liu, Q.; Liu, L.; Liu, S.; Zhang, Y.; Song, C.

    2015-12-01

    Glacial lake outburst floods (GLOFs)generally result in catastrophic damages and fatalities. The Himalayas, the world's highest mountains hosting large number of glaciers, have frequently suffered from GLOFs events in the past decades. Climatic warming-induced melting and retreating glaciers make glacial lakes expand obviously and urge the potential risk of GLOFs in Himalayas. However, our knowledge on the state of glacial lakes in the entire Himalayas is still limited. This study conducts a systematically satellite-based inventory to firstly reveal the evolution complex, regional difference and causes of Himalayan glacial lake changes in the whole Himalayas. Hundreds of Landsat images and Google Earth high resolution imagery were employed to extract the extents of glacial lakes at four epochs (circa1990, circa 2000, circa 2005 and circa 2010). Object-oriented mapping method was used to automatically map the lakes. In association with published glacier data (e.g., China Glacier Inventory, Randolph and GLIMS Glacier data), visual inspections and iterative checks for individual lake guarantee the accuracy of our results. This study demonstrates the spatial and topographic distributions, differences, heterogeneity of glacial lake changes and their causes. Our results show that Himalayan glacial lakes present a rapidly expanding state in general. Both disappeared lakes and new-formed lakes were observed, however, pre-existing glacial lakes contributed most to the total areal expansion. Himalayan glacial lakes appeared a clear altitudinal difference between north side and south side of main range. Evolutions of glacial lakes between eastern, western and central Himalaya were different, and the most rapidly expanding areas need to be more concerned. Climatic and geomorphic controls result in the heterogeneity of glacial lake changes. This study will help assess the potential risk of GLOFs and promote the public awareness of glacial disasters in high mountain areas.

  7. Forecasting Lake-Effect Snow in the Great Lakes Using NASA Satllite Data

    Science.gov (United States)

    Cipullo, Michelle; Molthan, Andrew; Shafer, Jackie; Case, Jonathan; Jedlovec, Gary

    2011-01-01

    This slide presentation reviews the forecast of the lake effect snow in the Great Lakes region using models and infrared estimates of Great Lake Surface Temperatures (GLSTs) from the MModerate Resolution Imaging Spectroradiometer (MODIS) instrument on Terra and Aqua satellites, and other satellite data. This study analyzes Lake Erie and Lake Ontario which produce storm total snowfall ranged from 8-18 inches off of Lake Ontario and 10-12 inches off of Lake Erie for the areas downwind.

  8. GRACE water storage estimates for the Middle East and other regions with significant reservoir and lake storage

    Science.gov (United States)

    Longuevergne, L.; Wilson, C. R.; Scanlon, B. R.; Crétaux, J. F.

    2013-12-01

    While GRACE (Gravity Recovery and Climate Experiment) satellites are increasingly being used to monitor total water storage (TWS) changes globally, the impact of spatial distribution of water storage within a basin is generally ignored but may be substantial. In many basins, water is often stored in reservoirs or lakes, flooded areas, small aquifer systems, and other localized regions with areas typically below GRACE resolution (~200 000 km2). The objective of this study was to assess the impact of nonuniform water storage distribution on GRACE estimates of TWS changes as basin-wide averages, focusing on surface water reservoirs and using a priori information on reservoir storage from radar altimetry. Analysis included numerical experiments testing effects of location and areal extent of the localized mass (reservoirs) within a basin on basin-wide average water storage changes, and application to the lower Nile (Lake Nasser) and Tigris-Euphrates basins as examples. Numerical experiments show that by assuming uniform mass distribution, GRACE estimates may under- or overestimate basin-wide average water storage by up to a factor of ~2, depending on reservoir location and areal extent. Although reservoirs generally cover less than 1% of the basin area, and their spatial extent may be unresolved by GRACE, reservoir storage may dominate water storage changes in some basins. For example, reservoir storage accounts for ~95% of seasonal water storage changes in the lower Nile and 10% in the Tigris-Euphrates. Because reservoirs are used to mitigate droughts and buffer against climate extremes, their influence on interannual timescales can be large. For example, TWS decline during the 2007-2009 drought in the Tigris-Euphrates basin measured by GRACE was ~93 km3. Actual reservoir storage from satellite altimetry was limited to 27 km3, but their apparent impact on GRACE reached 45 km3, i.e., 50% of GRACE trend. Therefore, the actual impact of reservoirs would have been greatly

  9. Lead Speciation in remote Mountain Lakes

    Science.gov (United States)

    Plöger, A.; van den Berg, C. M. G.

    2003-04-01

    In natural waters trace metals can become complexed by organic matter. This complexation can change the geochemistry of the metals by preventing them being scavenged, thereby increasing their residence time in the water column. The chemical speciation of trace metals also affects the bioavalability and their toxicological impact on organisms. It is therefore important to determine the chemical speciation of trace metals as well as their concentrations. Mountain lakes have been less studied in the past than other lakes- partly because of their remoteness and partly because they were perceived to be unpolluted and undisturbed. But work so far on mountain lakes has shown that most sites are affected and threatened, for example by transboundary air pollutants like trace metals. One of the important features that distinguishes these lakes from lowland lakes at similar latitudes is the fact that they may be isolated from the atmosphere for six months or more during the winter by a thick ice cover. Also, as these lakes are remote from direct anthropogenic influences, they reflect the regional distribution of pollutants transferred via the atmosphere. For this work, under the framework of the EMERGE (European Mountain lake Ecosystems: Regionalisation, diaGnostic and socio-economic Evaluation) programme, two remote mountain lakes have been studied in detail, with water sampling taking place at different times of the year to investigate possible seasonal differences in lead concentrations and speciation. Results so far have shown that lead-complexing ligand concentrations are in excess to dissolved lead concentrations, indicating that dissolved lead probably occurs fully complexed in these lakes. Therefore the toxic fraction is likely to be less than the dissolved lead concentration. Also, lead concentrations at the time of the spring thaw are higher than autumn concentrations just before ice cover, indicating that a significant proportion of fallout onto the lake catchment

  10. Seasonal Phenology and Life-History of Dendroctonus simplex (Coleoptera: Curculionidae) in the Great Lakes Region of North America.

    Science.gov (United States)

    McKee, Fraser R; Aukema, Brian H

    2016-08-01

    The eastern larch beetle, Dendroctonus simplex LeConte (Coleoptera: Curculionidae), is distributed throughout the North American boreal forest sympatric with its primary host, the eastern larch or tamarack, Larix laricina (Du Roi) K. Koch. Outbreaks of eastern larch beetles are typically small and associated with stressed tamaracks. Since 2000, however, an outbreak has killed >90,000 ha of tamarack in Minnesota and surrounding Great Lakes region. Identifying the causes of this epidemic is challenging due to knowledge gaps regarding the insect's biology. We present field data from 2011 to 2014 on degree days associated with spring emergence, dispersal, host colonization, and re-emergence from colonized hosts by mature adult beetles, as well as degree days associated with larval development, and prewinter emergence by adult progeny at study sites in northern Minnesota. After initial host colonization in early spring we found that a second brood was established in early summer by re-emerging parents. In 2012, a third brood was established. Across study years, first broods developed to adults by late summer, with many beetles relocating to the base of the host tree to overwinter. Second broods often reached adulthood and initiated prewinter emergence. The third brood of 2012 overwintered as adults, pupae, and late-instars, resuming development the following spring. Each spring, emergence of adult beetles from all broods established the previous year was highly synchronous. Knowledge of the biology of eastern larch beetles along the southern margin of their range aids in understanding how population dynamics may change with a changing climate.

  11. Geochemical evolution of Jurassic diorites from the Bristol Lake region, California, USA, and the role of assimilation

    Science.gov (United States)

    Young, E.D.; Wooden, J.L.; Shieh, Y.-N.; Farber, D.

    1992-01-01

    Late Jurassic dioritic plutons from the Bristol Lake region of the eastern Mojave Desert share several geochemical attributes with high-alumina basalts, continental hawaiite basalts, and high-K are andesites including: high K2O concentrations; high Al2O3 (16-19 weight %); elevated Zr/TiO2; LREE (light-rare-earth-element) enrichment (La/YbCN=6.3-13.3); and high Nb. Pearce element ratio analysis supported by petrographic relations demonstrates that P, Hf, and Zr were conserved during differentiation. Abundances of conserved elements suggest that dioritic plutons from neighboring ranges were derived from similar parental melts. In the most voluminous suite, correlated variations in elemental concentrations and (87Sr/86Sr)i indicate differentiation by fractional crystallization of hornblende and plagioclase combined with assimilation of a component characterized by abundant radiogenic Sr. Levenberg-Marquardt and Monte Carlo techniques were used to obtain optimal solutions to non-linear inverse models for fractional crystallization-assimilation processes. Results show that the assimilated material was chemically analogous to lower crustal mafic granulites and that the mass ratio of contaminant to parental magma was on the order of 0.1. Lack of enrichment in 18O with differentiation is consistent with the model results. Elemental concentrations and O, Sr, and Nd isotopic data point to a hydrous REE-enriched subcontinental lithospheric source similar to that which produced some Cenozoic continental hawaiites from the southern Cordillera. Isotopic compositions of associated granitoids suggest that partial melting of this subcontinental lithosphere may have been an important process in the development of the Late Jurassic plutonic arc of the eastern Mojave Desert. ?? 1992 Springer-Verlag.

  12. Nitrogen Cycling and Losses Under Rice-Wheat Rotations with Coated Urea and Urea in the Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Zhi; ZHU Jian-Guo; GAO Ren; H. YASUKAZU; FENG Ke

    2007-01-01

    A lysimeter experiment with undisturbed soil profiles was carried out to study nitrogen cycling and losses in a paddy soil with applications of coated urea and urea under a rice-wheat rotation system in the Taihu Lake region from 2001 to 2003. Treatments for rice and wheat included urea at conventional, 300 (rice) and 250 (wheat) kg N ha-1, and reduced levels, 150 (rice) and 125 (wheat) kg N ha-1, coated urea at two levels, 100 (rice) and 75 (wheat) kg N ha-1, and 150(rice) and 125 (wheat) kg N ha-1, and a control with no nitrogen arranged in a completely randomized design. The results under two rice-wheat rotations showed that N losses through both NH3 volatilization and runoff in the coated urea treatments were much lower than those in the urea treatments. In the urea treatments N runoff losses were significantly (P < 0.001) positively correlated (r = 0.851) with applied N. N concentration in surface water increased rapidly to maximum two days after urea application and then decreased quickly. However, if there was no heavy rain within five days of fertilizer application, the likelihood of N loss by runoff was not high. As the treatments showed little difference in N loss via percolation, nitrate N in the groundwater of the paddy fields was not directly related to N leaching. The total yieldof the two rice-wheat rotations in the treatment of coated urea at 50% conventional level was higher than that in the treatment of urea at the conventional level. Thus, coated urea was more favorable to rice production and environmental protection than urea.

  13. Investigation of Temperature Dynamics in Small and Shallow Reservoirs, Case Study: Lake Binaba, Upper East Region of Ghana

    Directory of Open Access Journals (Sweden)

    Ali Abbasi

    2016-03-01

    Full Text Available An unsteady fully three-dimensional model of Lake Binaba (a shallow small reservoir in semi-arid Upper East Region of Ghana has been developed to simulate its temperature dynamics. The model developed is built on the Reynolds Averaged Navier–Stokes (RANS equations, utilizing the Boussinesq approach. As the results of the model are significantly affected by the physical conditions on the boundaries, allocating appropriate boundary conditions, particularly over a water surface, is essential in simulating the lake’s thermal structure. The thermal effects of incoming short-wave radiation implemented as a heat source term in the temperature equation, while the heat fluxes at the free water surface, which depend on wind speed, air temperature, and atmospheric stability conditions are considered as temperature boundary condition. The model equations were solved using OpenFOAM CFD toolbox. As the flow is completely turbulent, which is affected by the complex boundary conditions, a new heat transfer solver and turbulence model were developed to investigate the spatial and temporal distribution of temperature in small and shallow inland water bodies using improved time-dependent boundary conditions. The computed temperature values were compared with four days of observed field data. Simulated and observed temperature profiles show reasonable agreement where the root mean square error (RMSE over the simulation period ranges from 0.11 to 0.44 °C in temporal temperature profiles with an average value of 0.33 °C. Results indicate that the model is able to simulate the flow variables and the temperature distribution in small inland water bodies with complex bathymetry.

  14. Clearing the Big Smog

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Beijing is trying to clean up its sky with a new standard for vehicle emissions From March 1,Beijing has imple- mented a new stricter vehicle emission standard that could lead to cleaner air,but also force thousands of cars off the road. StandardⅣ,the latest in a series of measures aimed at clearing the per- sistent smog,will match the current standard of the European Union. All the new light petro vehicles that are on sale in the Beijing market shall

  15. Pirla Project (paleoecological investigation of recent lake acidification): preliminary results for the Adirondacks, New England, Great Lakes States, and N. Florida

    Energy Technology Data Exchange (ETDEWEB)

    Charles, D.F.; Whitehead, D.R.; Anderson, D.S.; Bienert, R.; Camburn, K.E.; Cook, R.B.; Crisman, T.L.; Davis, R.B.; Ford, J.; Fry, B.D.; Hites, R.A.

    1986-01-01

    The PIRLA project is an interdisciplinary paleoecological study designed to provide reconstructions of the recent acidification histories of a representative set of lakes in four acid-sensitive regions in North America. We are trying to determine if lakes in the study regions have acidified, and if so, to what extent, over what time period and why. Sediment cores from 5 to 15 lakes in each region are being analyzed for several characteristics. Diatoms and chrysophytes are being used to reconstruct lake water pH. Results for three Adirondack lakes with current pH of 4.8 to 5.0 indicate a decrease in pH beginning in the 1930's-1950's. Increased atmospheric deposition of strong acids appears to be the primary factor responsible for the pH decline. Two lakes (pH 4.4 and 4.7) in New England show clear evidence of acidification probably due to acidic deposition. Preliminary reconstruction for two lakes in Michigan (pH 4.4 and 5.6), one in Wisconsin (pH 5.3), and one in Minnesota (pH 6.8) suggest no recent pH decrease. For the one Florida lake (pH 4.4) analyzed, inferred pH decreases by about 0.5 unit, beginning in the 1950s; the cause has not been determined.

  16. Delineation of level III aquatic ecological function regionalization in the Taihu Lake basin%太湖流域水生态功能三级分区

    Institute of Scientific and Technical Information of China (English)

    高永年; 高俊峰; 陈垌烽; 许妍; 赵家虎

    2012-01-01

    Aquatic ecoregions have been used as spatial units for aquatic ecosystem management at the watershed scale. According to the protection requirements and characteristics of aquatic ecosystems in the Taihu Lake basin, the main purpose and the principles of level III aquatic ecological function regionalization delineation in this basin were proposed. Then the indicators for delineating level III aquatic ecological function regionalization were established based on regionalization objective and principles. The indicators for delineating level Ili aquatic ecological function regionalization in the non-Taihu Lake area included benthic Shannon-Wiener diversity index, chlorophyll content, water habitat types and benthic indicator species types (including Ephemera, Bivalvia, snail, Chironomidae and Oligochaeta), and the regionalization indicators for delineating level III aquatic ecological function regionalization in the Taihu Lake area included benthic Shannon-Wiener diversity index, chlorophyll content, water flow velocity and benthic indicator species (including Oligochaeta, Chironomidae class, Bivalvia, snail and others) ratio. With the aid of GIS technology, the spatial distribution of the indicators for level III aquatic ecological function regionalization delineation was identified based on the raster data from 1106 aquatic ecoregion function units in the non-Taihu Lake area and 3568 aquatic ecoregion function units in the Taihu Lake area, respectively. Two-step spatial clustering analysis approach and manual-assisted method were used to delineate level III aquatic ecological function zones. Then the Taihu Lake basin was divided into 21 level III aquatic ecological function zones. Moreover, the characteristics of the 21 zones were summarized, showing that there were significant differences in the aspects such as topography, soil type, water quality and aquatic ecology. The results of quantitative comparison of aquatic life also indicated that the benthic dominant

  17. Modeling of temporal patterns and sources of atmospherically transported and deposited pesticides in ecosystems of concern: A case study of toxaphene in the Great Lakes

    Science.gov (United States)

    Li, Rong; Jin, Jiming

    2013-10-01

    have adverse effects on human health and the environment and can be transported through the atmosphere from application sites and deposited to sensitive ecosystems. This study applies a comprehensive multimedia regional pesticide fate and chemical transport modeling system that we developed to investigate the atmospheric transport and deposition of toxaphene to the Great Lakes. Simulated results predict a significant amount of toxaphene (~350 kg) being transported through the atmosphere and deposited into the Great Lakes in the simulation year. Results also show that U.S. residues and global background are major sources to toxaphene deposition into the Great Lakes and atmospheric concentrations in the region. While the U.S. residues are the dominant source in warm months, the background dominates during winter months. In addition, different sources have different influences on the individual Great Lakes due to their proximity and relative geographical positions to the sources; U.S. residues are the dominant source to Lakes Ontario, Erie, Huron, and Michigan, but they are a much less important source to Lake Superior. These results shed light on the mystery that observed toxaphene concentrations in Great Lakes' lake trout and smelt declined between 1982 and 1992 in four of the Great Lakes except Lake Superior. While monthly total depositions to Lakes Ontario, Erie, Huron, and Michigan have clear seasonal variability with much greater values in April, May, and June, monthly total depositions to Lake Superior are more uniformly distributed over the year with comparatively greater levels in cold months.

  18. Estimating the regional climate signal in a late Pleistocene and early Holocene lake-sediment δ18O record from Vermont, USA.

    Science.gov (United States)

    Mandl, Maximilian Benedict; Shuman, Bryan Nolan; Marsicek, Jeremiah; Grigg, Laurie

    2016-07-01

    We present a new oxygen isotope (δ18O) record from carbonate-rich lake sediments from central Vermont. The record from Twin Ponds spans from 13.5 cal ka BP (1950 AD) to present, but contains a 6 ka long hiatus starting shortly after 7.5 cal ka BP. We compare the record for ca. 13.5-7.5 cal ka BP with published δ18O data from the region after using a Bayesian approach to produce many possible chronologies for each site. Principal component analysis then identified chronologically-robust, multi-site oxygen isotope signals, including negative values during the Younger Dryas, but no significant deviations from the early Holocene mean of the regional records. However, differences among sites indicate significant trends that likely relate to interacting changes in the regional gradients of seasonal temperatures and precipitation as well as moisture sources, moisture pathways, and aridity that were controlled by large-scale climatic controls such as insolation, the progressive decline of the Laurentide Ice Sheet, and changes in oceanic circulation. Centennial shifts punctuate these trends at ca. 9.3 and 8.2 cal ka BP, and reveal that the local character of these short-lived features requires a detailed understanding of lake hydrology and regional isotopic gradients to yield reliable information for regional climate reconstructions.

  19. Optical Properties of Polish Lakes: The Secchi Disc Transparency

    Directory of Open Access Journals (Sweden)

    Borowiak Dariusz

    2015-03-01

    Full Text Available The spatial variation of water transparency of the largest Polish lakes was presented on the basis of documentary material collected by the Voivodeship Inspectorates for Environment Protection as well as university geography departments in the period of 1991-2013. Seasonal results of the Secchi disc measurements (spring, summer for 706 lakes were gathered. This is more than 68% of the total number of Polish lakes with a surface area larger than 50 ha. The mean water transparency of these lakes was 1.87 m, while the median was 1.58 m. Distinct inter-regional differences of the Secchi disc transparency were found, and it was also possible to distinguish three relatively homogeneous groups of macroregions where lakes have different optical characteristics. They can be divided into areas with lakes with high (3.05 m, medium (1.99-2.11 m and low (1.22-1.52 m water transparency. The Secchi disc transparency of these lakes was also analysed in relation to concentration values of the main forms of the optically significant constituents of water (coloured dissolved organic matter, suspended matter. The mean transparency of turbid, stained and clear lakes was, respectively, 1.16, 2.02, and 2.92 m. Moreover, regional empirical models to predict Secchi disc transparency from chlorophyll a concentration were also developed. It was assumed that inter-regional differences between models could be due to the probably different time of the ice sheet recession. The influence of the lake morphometry was most fully reflected in the impact of the depth conditions.

  20. Landscapes of Lake Baikal: «To protect or to build» Town planning motivations of the stable development of the region

    Directory of Open Access Journals (Sweden)

    Andrei Bolshakov

    2006-03-01

    Full Text Available Building, planning, engineering facilities of the inhabited places of Lake Baikal and organization of the recreational areas for tourists, as well as organization of the particularly reserved natural territories should maintain everlastingly untouched the beauty and the cleanness, the natural diversity and the uniqueness of the nature of Lake Baikal, that makes it glorious and attracts tourists and inhabitants so much. Is it possible? And how to combine technical conditions of civilization, to which we have got used so much (energy supply, canalization, asphalt roads, automobile transport, oilpipelines, developed cities and villages, and aspiration of many investors, who would like to organize a profitable tourist business, together with the goal to protect the nature of Lake Baikal.To protect or to develop the landscapes of Lake Baikal, and which landscapes to urbanize and which to restore, and how to equip the developed territories, and how to maintain the protected natural landscapes–these questions compose a complex national task. Its accomplishment is firstly based on studying and maintaining the diversity of landscapes of the region and its importance as the global natural heritage. Secondly, the stable development of the region is possible only when solving the conflicts of landutilization motivations in a right way at the expense of building the rational network of the Baikal landscapes from the reserved to the urbanized ones.

  1. Adaption oder Anpassung? Umweltbewusstsein in der Region um den Plattensee/Balaton (Adaptation or a Change in Attitude? Environmental Awareness in the Region of Lake Balaton

    Directory of Open Access Journals (Sweden)

    Magdolna Leveleki

    2016-04-01

    . According to our analyses, there are no apparent ecologically desirable changes among the inhabitants of the region of Lake Balaton, and when examining the social differentiation of the trends, one does not find any sign of higher environmental awareness among young people — who, according to Eurobarometer surveys tend to show higher environmental sensitivity. The results of our measures show that the social differences are attributed, therefore, not to age groups, but to the degree of education and to philosophical belief. The questionnaire, which was conducted among the permanent population of the Balaton region also identified a huge gap between the values and the acceptance of the environmentally friendly forms of action. Even though environmental values usually score at the top of the pyramide of values, support for actions aiming at solving environmental problems is not too strong.

  2. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Kathryn L. Cottingham

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  3. Ecology of playa lakes

    Science.gov (United States)

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  4. First Year Results from the Circumarctic Lakes Observation Network (CALON) Project

    Science.gov (United States)

    Hinkel, K. M.; Arp, C. D.; Frey, K. E.; Lenters, J. D.; Beck, R. A.; Eisner, W. R.; Gaglioti, B.; Grosse, G.; Jones, B. M.; Kim, C.; Liu, H.; Townsend-Small, A.

    2012-12-01

    variability related to snow depth. Rapid warming follows ice-off, with water temperature responding synchronously to synoptic weather variations across the area. Regionally, ice-off occurs 2-4 weeks later on lakes near the coast, but with high inter-lake variability related to lake depth and area. Inland lakes are warmer in mid-summer than those near the coast, reflecting the regional climate gradient and the maritime effect. All lakes are well-mixed and largely isothermal, with some thermal stratification occurring during calm, sunny periods in deeper lakes. This project also involves measurement of carbon and nutrient dynamics and inorganic geochemistry of the lakes. Preliminary data indicate that brown colored lakes have greater dissolved methane concentrations under ice in winter than clear-water lakes, which is promising for remote sensing applications. Through a collaborative effort between the USGS-Alaska Science Center, the BLM Arctic Field Office, the NSF and other partners, we have established the Teshekpuk Lake Observatory as part of the CALON project in order to assess the past, present, and future response of Teshekpuk Lake ecosystem to environmental stressors and change. All data resulting from this 4-year project will be stored at CADIS and a specially designed web portal, and is currently accessible through the CALON web page at https://sites.google.com/a/giesn.com/nsf-calon/.

  5. Aggregating Hydrometeorological Data from International Monitoring Networks Across Earth's Largest Lake System to Quantify Uncertainty in Historical Water Budget Records, Improve Regional Water Budget Projections, and Differentiate Drivers Behind a Recent Record-Setting Surge in Water Levels

    Science.gov (United States)

    Gronewold, A.; Bruxer, J.; Smith, J.; Hunter, T.; Fortin, V.; Clites, A. H.; Durnford, D.; Qian, S.; Seglenieks, F.

    2015-12-01

    Resolving and projecting the water budget of the North American Great Lakes basin (Earth's largest lake system) requires aggregation of data from a complex array of in situ monitoring and remote sensing products that cross an international border (leading to potential sources of bias and other inconsistencies), and are relatively sparse over the surfaces of the lakes themselves. Data scarcity over the surfaces of the lakes is a particularly significant problem because, unlike Earth's other large freshwater basins, the Great Lakes basin water budget is (on annual scales) comprised of relatively equal contributions from runoff, over-lake precipitation, and over-lake evaporation. Consequently, understanding drivers behind changes in regional water storage and water levels requires a data management framework that can reconcile uncertainties associated with data scarcity and bias, and propagate those uncertainties into regional water budget projections and historical records. Here, we assess the development of a historical hydrometeorological database for the entire Great Lakes basin with records dating back to the late 1800s, and describe improvements that are specifically intended to differentiate hydrological, climatological, and anthropogenic drivers behind recent extreme changes in Great Lakes water levels. Our assessment includes a detailed analysis of the extent to which extreme cold winters in central North America in 2013-2014 (caused by the anomalous meridional upper air flow - commonly referred to in the public media as the "polar vortex" phenomenon) altered the thermal and hydrologic regimes of the Great Lakes and led to a record setting surge in water levels between January 2014 and December 2015.

  6. Growth Responses of Trees to Micronutrients and Their Feedback Effect in Various Soil-Forest Ecosystems of Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients, B, Mo, Cu, Zn, Fe, and Mn, in soils derived from various parent materials in the forest area of Taihu Lake region in southeast China. The results showed that the dry weight of individual current-year needle of Chinese fir (Cunninghamia lanceolata) grown on the soil derived from granite parent rock was increased by 8% and 13% in comparison with that grown on the soils derived from sandstone and ash-tuff parent rock, respectively. And such dry weight of loblolly pine (Pinus taeda) grown on the soil derived from sandstone parent rock was increased by 21% in comparison with that on the soil derived from ash-tuff parent rock. One of the reasons for those results was that micronutrients content in the soil derived from ash-tuff parent rock were not sufficient to meet the requirement of the growth of Chinese fir and loblolly pine, i.e., micronutrients in soil were deficient and/or induced deficient. The amounts of Cu, Zn, Fe, and Mn uptake by Chinese fir and loblolly pine were in agreement with the contents of available micronutrients in soil respectively, except for B and Mo. Meanwhile, there might exist an "antagonism" between the uptake of B versus Mo by trees, although more studies are needed to confirm it. Regression analysis indicated that amount of a soil available micronutrient was correlated to the type of parent material and its total amount in the forest floor, except for B. The F test identified that the correlation of each equation reached the significant level to different extents, respectively. The t test confirmed that amount of available forms was mainly depended on the type of parent material for Mo, Cu, Zn and Mn but on the forest floor for Fe. There was a feedback effect of forest stand on the amount of soil available micronutrients. The ability of accumulating available micronutrients in soil was better by the

  7. Quantifying methane emissions from rice fields in the Taihu Lake region, China by coupling a detailed soil database with biogeochemical model

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2009-05-01

    Full Text Available As China has approximately 22% of the world's rice paddies, the regional quantification of CH4 emissions from these paddies is important in determining their contribution to the global greenhouse gas effect. This paper reports the use of a biogeochemical model (DeNitrification and DeComposition or DNDC for quantifying CH4 emissions from rice fields in the Taihu Lake region of China. For this application, the DNDC model was linked to a 1:50 000 soil database derived from 1107 paddy soil profiles compiled during the Second National Soil Survey of China in the 1980s–1990s. The simulated results showed that the 2.3 Mha of paddy rice fields in the Taihu Lake region emitted the equivalent of 5.7 Tg C from 1982–2000, with the average CH4 flux ranging from 114 to 138 kg C ha−1 y−1. As for soil subgroups, the highest emission rate (660 kg C ha−1 y−1 was linked to gleyed paddy soils accounting for about 4.4% of the total area of paddy soils. The lowest emission rate (91 kg C ha−1 y−1 was associated with degleyed paddy soils accounting for about 18% of the total area of paddy soils. The most common soil in the area was hydromorphic paddy soils, which accounted for about 53% of the total area of paddy soils with a CH4 flux of 106 kg C ha−1 y−1. On a regional basis, the annual averaged CH4 flux in the Taihu Lake plain soil region and alluvial plain soil region were higher than that in the low mountainous and hilly soil region and the polder soil region. The model simulation was conducted with two databases using polygons or counties as the basic units. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns of CH4 emissions in the Taihu

  8. Research on Material Composition of Salt Lakes In Tenggeli Desert Region%腾格里沙漠区盐湖物质成分研究

    Institute of Scientific and Technical Information of China (English)

    刘振敏

    2000-01-01

    腾格里沙漠面积广阔,区内分布着数十个盐湖,盐湖面积大的为十余平方千米,小的仅 为0.018km2。盐湖卤水主要为湖表卤水,其矿化度较高,大部分盐湖卤水含盐量已达饱和 ,因而进入了自析盐阶段。盐湖卤水化学成分以Na+、K+、Cl-、SO42-、HCO 3-、CO32-为主,占卤水总含盐量的99%,卤水中还有B2O3、Li、I、Br 等微量元素。盐湖盐类沉积有碳酸盐类、硫酸盐类和氯化物型盐类、主要盐类矿物为芒硝、 钾芒硝、天然碱、泡碱、碳钾钠矾、石盐等。盐湖粘土矿物组合以蒙脱石的普遍存在为特征 ,含有少量的伊利石和水云母。%There are a lot of salt lakes in Tenggeli desert region, the salt lakes vary in area from a few Sq.km to tens Sq.km, they are part of salt lakes in China. Bot h brines and saline deposit exist in the saline lakes, the superficial brines of salt lakes are mainly of brines type, its salinity is comparatively high, it co nsists of Na+,K+,Ca2+,Mg2+,Cl-,SO42-,HCO3-,CO3 2-, and B,Li,Br,I and so on. Saline deposits of salt lake consist of more t han 10 salt minerals, but the glauber salt, glaserite, pgrotechnite, hanksite, n atron, trona and halite are mainly salt minerals. The clay minerals has askanite , glimmerton and hydromica.

  9. Consciousness CLEARS the mind.

    Science.gov (United States)

    Grossberg, Stephen

    2007-11-01

    A full understanding of consciousness requires that we identify the brain processes from which conscious experiences emerge. What are these processes, and what is their utility in supporting successful adaptive behaviors? Adaptive Resonance Theory (ART) predicted a functional link between processes of Consciousness, Learning, Expectation, Attention, Resonance and Synchrony (CLEARS), including the prediction that "all conscious states are resonant states". This connection clarifies how brain dynamics enable a behaving individual to autonomously adapt in real time to a rapidly changing world. The present article reviews theoretical considerations that predicted these functional links, how they work, and some of the rapidly growing body of behavioral and brain data that have provided support for these predictions. The article also summarizes ART models that predict functional roles for identified cells in laminar thalamocortical circuits, including the six layered neocortical circuits and their interactions with specific primary and higher-order specific thalamic nuclei and nonspecific nuclei. These predictions include explanations of how slow perceptual learning can occur without conscious awareness, and why oscillation frequencies in the lower layers of neocortex are sometimes slower beta oscillations, rather than the higher-frequency gamma oscillations that occur more frequently in superficial cortical layers. ART traces these properties to the existence of intracortical feedback loops, and to reset mechanisms whereby thalamocortical mismatches use circuits such as the one from specific thalamic nuclei to nonspecific thalamic nuclei and then to layer 4 of neocortical areas via layers 1-to-5-to-6-to-4.

  10. Late-glacial and Holocene Vegetation and Climate Variability, Including Major Droughts, in the Sky Lakes Region of Southeastern New York State

    Science.gov (United States)

    Menking, Kirsten M.; Peteet, Dorothy M.; Anderson, Roger Y.

    2012-01-01

    Sediment cores from Lakes Minnewaska and Mohonk in the Shawangunk Mountains of southeastern New York were analyzed for pollen, plantmacrofossils, macroscopic charcoal, organic carbon content, carbon isotopic composition, carbon/nitrogen ratio, and lithologic changes to determine the vegetation and landscape history of the greater Catskill Mountain region since deglaciation. Pollen stratigraphy generally matches the New England pollen zones identified by Deevey (1939) and Davis (1969), with boreal genera (Picea, Abies) present during the late Pleistocene yielding to a mixed Pinus, Quercus and Tsuga forest in the early Holocene. Lake Minnewaska sediments record the Younger Dryas and possibly the 8.2 cal kyr BP climatic events in pollen and sediment chemistry along with an 1400 cal yr interval of wet conditions (increasing Tsuga and declining Quercus) centered about 6400 cal yr BP. BothMinnewaska andMohonk reveal a protracted drought interval in themiddle Holocene, 5700-4100 cal yr BP, during which Pinus rigida colonized the watershed, lake levels fell, and frequent fires led to enhanced hillslope erosion. Together, the records show at least three wet-dry cycles throughout the Holocene and both similarities and differences to climate records in New England and central New York. Drought intervals raise concerns for water resources in the New York City metropolitan area and may reflect a combination of enhanced La Niña, negative phase NAO, and positive phase PNA climatic patterns and/or northward shifts of storm tracks.

  11. Spatio-temporal assessment of soil erosion risk in different agricultural zones of the Inle Lake region, southern Shan State, Myanmar.

    Science.gov (United States)

    Htwe, Thin Nwe; Brinkmann, Katja; Buerkert, Andreas

    2015-10-01

    Myanmar is one of Southeast Asia's climatically most diverse countries, where sheet, rill, and gully erosion affect crop yields and subsequently livelihood strategies of many people. In the unique wetland ecosystem of Inle Lake, soil erosion in surrounding uplands lead to sedimentation and pollution of the water body. The current study uses the Revised Universal Soil Loss Equation (RUSLE) to identify soil erosion risks of the Inle Lake region in space and time and to assess the relationship between soil erosion and degradation for different agricultural zones and cropping systems. Altogether, 85% of soil losses occurred on barren land along the steep slopes. The hotspot of soil erosion risk is situated in the western uplands characterized by unsustainable land use practices combined with a steep topography. The estimated average soil losses amounted to 19.9, 10.1, and 26.2 t ha(-1) yr(-1) in 1989, 2000, and 2009, respectively. These fluctuations were mainly the results of changes in precipitation and land cover (deforestation (-19%) and expansion of annual cropland (+35%) from 1989 to 2009). Most farmers in the study area have not yet adopted effective soil protection measures to mitigate the effects of soil erosion such as land degradation and water pollution of the lake reservoir. This urgently needs to be addressed by policy makers and extension services.

  12. Testing a participatory integrated assessment(PIA) approach to select climate change adaptation actions to enhance wetland sustainability: The case of Poyang Lake region in China

    Institute of Scientific and Technical Information of China (English)

    HUANG; Li; YIN; Yongyuan; DU; De-Bin

    2015-01-01

    The necessity of mainstreaming climate adaptation strategies or policies into natural resource management plans has been recognized by the UNFCCC.The IPCC AR5 report suggests a growing demand for research to provide information for a deeper and more useful understanding of climate adaptation options,and indicates a lack of effective methods to meet this increasing demand of policymakers.In this respect,a participatory integrated assessment(PIA) approach is presented in this paper to provide an effective means to mainstream wetland climate change adaptation in rural sustainable development strategies,and thus to reduce climate vulnerability and to enhance rural community livelihood.The PIA approach includes a series of research activities required to assess climate impacts on wetland ecosystems,and to prioritize adaptation responses.A range of adaptation options that address key aspects of the wetland ecosystem resilience and concerns are evaluated against community based on sustainable development indicators.The PIA approach is able to identify desirable adaptation options which can then be implemented to improve wetland ecosystem health and to enhance regional sustainable development in a changing climate.For illustration purpose,the PIA was applied in a case study in Poyang Lake(PYL) region,a critical wetland and water ecosystem in central China with important international biodiversity linkages,and a locale for key policy experiments with ecosystem rehabilitation.The PIA was used to facilitate the integration of wetland climate change adaptation in rural sustainable development actions with multi-stakeholders participation.In particular,the case shows how the PIA can be designed and implemented to select effective and practical climate change adaptation options to enhance ecosystem services management and to reduce resource use conflicts and rural poverty.Worked in partnership with multi-stakeholders and assisted with a multi-criteria decision making tool

  13. New lakes in de-glaciating high-mountain regions - a challenge for integrative research about hazard protection and sustainable use

    Science.gov (United States)

    Haeberli, W.

    2012-12-01

    As a consequence of rapid glacier vanishing, an increasing number of smaller and larger lakes are forming in high-mountain regions worldwide. Such new lakes can be touristic landscape attractions and may also represent interesting potentials for hydropower production. However, they more and more often come into existence at the foot of very large and steep icy mountain walls, which are progressively destabilizing due to changing surface and subsurface ice conditions. The probability of far-reaching flood and debris flow catastrophes caused by impact waves from large rock/ice avalanches into lakes may still appear to be small now but steadily increases for long time periods to come. Corresponding projects related to hazard protection and sustainable use should be combined in an integrative and participatory planning process. This planning process must start soon, because the development in nature is fast and most likely accelerating. Technical tools for creating the necessary scientific knowledge basis at local to regional scales exist and can be used. The location of future new lakes in topographic bed depressions of now still glacier-covered areas can be quite safely assessed on the basis of morphological criteria or by applying ice thickness estimates using digital terrain information. Models for ice-thickness estimates couple the depth to bedrock via the basal shear stress with the surface slope and provide a (relative) bed topography which is much more robust than the (absolute) value of the calculated ice thickness. Numerical models at various levels of sophistication can be used to simulate possible future glacier changes in order to establish the probable time of lake formation and the effects of glacier shrinking on runoff seasonality and water supply. The largest uncertainties thereby relate to the large uncertainties of (absolute) ice thickness and mass/energy fluxes at the surface (climate scenarios, precipitation and albedo changes, etc.). Combined

  14. Evidence of recent changes in the ice regime of lakes in the Canadian High Arctic from spaceborne satellite observations

    Directory of Open Access Journals (Sweden)

    C. M. Surdu

    2015-11-01

    Full Text Available Arctic lakes, through their ice cover phenology, are a key indicator of climatic changes that the high-latitude environment is experiencing. In the case of lakes in the Canadian Arctic Archipelago (CAA, many of which are ice covered more than ten months per year, warmer temperatures could result in ice regime shifts. Within the dominant polar-desert environment, small local warmer areas have been identified. These relatively small regions – polar oases – with longer growing seasons, greater biological production and diversity, are confined from the surrounding barren polar desert. The ice regimes of 11 lakes located in both polar-desert and polar-oasis environments, with surface areas between 4 and 542 km2, many of unknown bathymetry, were documented. In order to investigate the response of ice cover of lakes in the CAA to climate conditions during recent years, a 15-year time series (1997–2011 of RADARSAT-1/2 ScanSAR Wide Swath, ASAR Wide Swath and Landsat acquisitions were analysed. Results show that melt onset (MO occurred earlier for all observed lakes. With the exception of Lower Murray Lake, all lakes experienced earlier summer-ice minimum and water-clear-of-ice dates (WCI, with greater changes being observed for polar-oasis lakes (9–24 days earlier WCI dates for lakes located in polar oases and 2–20 days earlier WCI dates for polar-desert lakes. Additionally, results suggest that some lakes may be transitioning from a perennial/multiyear to a seasonal ice regime, with only a few lakes maintaining a multiyear ice cover on occasional years. Aside Lake Hazen and Murray Lakes that preserved their ice cover during the summer of 2009, no residual ice was observed on any of the other lakes from 2007 to 2011.

  15. Evidence of recent changes in the ice regime of lakes in the Canadian High Arctic from spaceborne satellite observations

    Science.gov (United States)

    Surdu, Cristina M.; Duguay, Claude R.; Fernández Prieto, Diego

    2016-05-01

    Arctic lakes, through their ice cover phenology, are a key indicator of climatic changes that the high-latitude environment is experiencing. In the case of lakes in the Canadian Arctic Archipelago (CAA), many of which are ice covered more than 10 months per year, warmer temperatures could result in ice regime shifts. Within the dominant polar-desert environment, small local warmer areas have been identified. These relatively small regions - polar oases - with longer growing seasons and greater biological productivity and diversity are secluded from the surrounding barren polar desert. The ice regimes of 11 lakes located in both polar-desert and polar-oasis environments, with surface areas between 4 and 542 km2, many of unknown bathymetry, were documented. In order to investigate the response of ice cover of lakes in the CAA to climate conditions during recent years, a 15-year time series (1997-2011) of RADARSAT-1/2 ScanSAR Wide Swath, ASAR Wide Swath, and Landsat acquisitions were analyzed. Results show that melt onset occurred earlier for all observed lakes. With the exception of Lower Murray Lake, all lakes experienced earlier summer ice minimum and water-clear-of-ice (WCI) dates, with greater changes being observed for polar-oasis lakes (9-24 days earlier WCI dates for lakes located in polar oases and 2-20 days earlier WCI dates for polar-desert lakes). Additionally, results suggest that some lakes may be transitioning from a perennial/multiyear to a seasonal ice regime, with only a few lakes maintaining a multiyear ice cover on occasional years. Aside Lake Hazen and Murray Lakes, which preserved their ice cover during the summer of 2009, no residual ice was observed on any of the other lakes from 2007 to 2011.

  16. The Deterioration of Ecology Environment and Its Cause in the Lake Regions of the Yellow River Source, Qinghai, China%黄河源区生态环境恶化的现状及其原因

    Institute of Scientific and Technical Information of China (English)

    郑本兴; 唐邦兴; 李成治

    2001-01-01

    黄河是中华民族的母亲河,黄河流域是世界上著名的四大文明古国的发祥地之一。远古时代黄河流域气候湿润、水源丰富、土地肥沃。轩猿黄帝和他的沿黄部落就在这里开始创造中华文明。而今黄河下游常年发生断流,中游水土流失严重,河源区生态环境恶化,已引起我国政府和民众的关注。目前,防治黄河源区生态环境进一步恶化的研究工作必须加大力度,在财力、人力方面应给予更大的支持,及早编制该区治理生态环境的规划,加强环境保护措施。%The Yellow River is the mother river of the Chinese nation, andthe watersheds of the Yellow River is also one of four famous countries with an ancient civilization in the World. In remote antiquity, the climate was warm and moist, abundant water resources and good soil favorite to the Xuanyuan Emporia and his tribe lived along both sides of the Yellow River, and created a Chinese civilization. But at present a broken flow of the Yellow River is frequent in the lower reach and heavy soil erosion in the middle reach, ecological environment steadily deteriorated in the headwater. Attention has be paid to these situations by the chinese Government and their people.Over the confluence of the Maqu River and Heihe River (the range before the Huashixia)is called the source region of the Yellow River with an area of 22000km2, the length of the riverbed 323km from the Maqu River to the headwater with slope of 1.2%o. The whole source region is a Cenozoic tectonic depression situated between Buqingshan and Bar Yanhara Mountains, and can be divided into five landform units based on geomorphologic features, and show as follow from north to south: 1.Zagarishan-Buqingshan high-middle mountainous region 2.Joguzhongle Basin-Xinsuhai Lake-Gyaring Lake-Ngoring Lake-Maqu River broad-valley basin region 3.Joguzhongle Mountain-Mianshaling Ridge lower mountain-hill region 4.Kariqu River

  17. The PIRLA project (Paleoecological investigation of recent lake acidification). Preliminary results for the Adirondacks, New England, N. Great Lakes States, and N. Florida

    Energy Technology Data Exchange (ETDEWEB)

    Charles, D.F.; Whitehead, D.R.; Anderson, D.S.; Bienert, R.; Camburn, K.E.; Cook, R.B.; Crisman, T.L.; Davis, R.B.; Ford, J.; Fry, B.D.

    1986-09-01

    The PIRLA project is an interdisciplinary paleoecological study designed to provide reconstructions of the recent acidification histories of a representative set of lakes in four acid-sensitive regions in North America. We are trying to determime if lakes in the study regions have acidified, and if so, to what extent, over what time period and why. Sediment cores from 5 to 15 lakes in each region are being analyzed for several characteristics. Diatoms and chrysophytes are being used to reconstruct lakewater pH. Results for three Adirondack lakes with current pH of 4.8 to 5.0 indicate a decrease in pH beginning in the 1930's-1950's. Increased atmospheric deposition of strong acids appears to be the primary factor responsible for the pH decline. Two lakes (pH 4.4 and 4.7) in New England show clear evidence of acidification probably due to acidic deposition. Preliminary reconstructions for two lakes in Michigan (pH 4.4 and 5.6), one in Wisconsin (pH 5.3), and one in Minnesota (pH 6.8) suggest no recent pH decrease. For the one Florida lake (pH 4.4) analyzed, inferred pH decreases by about 0.5 unit, beginning in the 1950's; the cause has not been determined. 26 refs.

  18. Ion clearing in an ERL

    Science.gov (United States)

    Hoffstaetter, Georg H.; Liepe, Matthias

    2006-02-01

    The rest-gas in the beam-pipe of a particle accelerator is readily ionized by effects like collisions, synchrotron radiation and field emission. Positive ions are attracted to electron beams and create a nonlinear potential in the vicinity of the beam which can lead to beam halo, particle loss, optical errors or transverse and longitudinal instabilities. In an energy recovery linac (ERL) where beam-loss has to be minimal, and where beam positions and emittances have to be very stable in time, these ion effects have to be avoided. Here we investigate three measures of avoiding ion accumulation: (a) A long gap between linac bunch trains that allows ions to drift out of the beam region, a measure regularly applied in linacs; (b) a short ion clearing gap in the beam that leads to a time varying beam potential and produces large excited oscillations of ions around the electron beam, a measure regularly applied in storage rings; (c) Clearing electrodes that create a sufficient voltage to draw ions out of the beam potential, a measure used for DC electron beams and for antiproton beams. For the parameters of the X-ray ERL planned at Cornell University we show that method (a) cannot be applied, method (b) is technically cumbersome, and (c) should be most easily applicable.

  19. The Road Inventory of Clear Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To determine the relative needs of the U.S. Fish and Wildlife Service, the Federal Highway Administration (FHWA) was asked to inventory all public access and...

  20. Spatiotemporal patterns of mercury accumulation in lake sediments of western North America.

    Science.gov (United States)

    Drevnick, Paul E; Cooke, Colin A; Barraza, Daniella; Blais, Jules M; Coale, Kenneth H; Cumming, Brian F; Curtis, Chris J; Das, Biplob; Donahue, William F; Eagles-Smith, Collin A; Engstrom, Daniel R; Fitzgerald, William F; Furl, Chad V; Gray, John E; Hall, Roland I; Jackson, Togwell A; Laird, Kathleen R; Lockhart, W Lyle; Macdonald, Robie W; Mast, M Alisa; Mathieu, Callie; Muir, Derek C G; Outridge, Peter M; Reinemann, Scott A; Rothenberg, Sarah E; Ruiz-Fernández, Ana Carolina; Louis, Vincent L St; Sanders, Rhea D; Sanei, Hamed; Skierszkan, Elliott K; Van Metre, Peter C; Veverica, Timothy J; Wiklund, Johan A; Wolfe, Brent B

    2016-10-15

    For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2μg/m(2) per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakes with no/little watershed development were controlled primarily by relative watershed size prior to 1850, and since have exhibited modest increases (in absolute terms and compared to that described above) associated with (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, mercury deposited to watersheds is delivered to lakes. Research is warranted to understand whether mountainous watersheds act as permanent sinks for mercury or if export of "legacy" mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.

  1. Spatiotemporal patterns of mercury accumulation in lake sediments of western North America

    Science.gov (United States)

    Drevnick, Paul; Cooke, Colin A.; Barraza, Daniella; Blais, Jules M.; Coale, Kenneth; Cumming, Brian F.; Curtis, Chris; Das, Biplob; Donahue, William F.; Eagles-Smith, Collin A.; Engstrom, Daniel R.; Fitzgerald, William F.; Furl, Chad V.; Gray, John R.; Hall, Roland I.; Jackson, Togwell A.; Laird, Kathleen R.; Lockhart, W. Lyle; Macdonald, Robie W.; Mast, M. Alisa; Mathieu, Callie; Muir, Derek C.G.; Outridge, Peter; Reinemann, Scott; Rothenberg, Sarah E.; Ruiz-Fernandex, Ana Carolina; St. Louis, V.L.; Sanders, Rhea; Sanei, Hamed; Skierszkan, Elliott; Van Metre, Peter C.; Veverica, Timothy; Wiklund, Johan A.; Wolfe, Brent B.

    2016-01-01

    For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2 μg/m2 per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakes with no/little watershed development were controlled primarily by relative watershed size prior to 1850, and since have exhibited modest increases (in absolute terms and compared to that described above) associated with (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, <1% of mercury deposited to watersheds is delivered to lakes. Research is warranted to understand whether mountainous watersheds act as permanent sinks for mercury or if export of “legacy” mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.

  2. SHRIMP U-Pb zircon dates from igneous rocks from the Fontana Lake region, Patagonia: Implications for the age of magmatism, Mesozoic geological evolution and age of basement

    Directory of Open Access Journals (Sweden)

    A.P. Rolando

    2004-12-01

    Full Text Available In the eastern margin of the Patagonian Andes and between 44° 30´S and 45° 30´S (Fontana Lake region, Middle Jurassic to Early Cretaceous volcanic and sedimentary rocks were intruded by granitic bodies during the Cretaceous. The reconstruction of the Jurassic-Cretaceous magmatic evolution in the Fontana Lake region and in the adjacent Patagonian Batholith was made possible by the consideration of the following characteristics: distribution in time and space of several intrusive bodies, retro-arc basin formation and volcanic intensity. U-Pb SHRIMP dating of zircon crystals from an ignimbrite, a dacitic porphyry and two granitoid rocks yielded dates of 148.7 ± 2.3, 144.5 ± 1.6, 117 ± 1.7 and 99.6 ± 2.8 Ma, respectively. The Cerro Bayo Ignimbrite (148.7 ± 2.3 Ma, Late Jurassic was included in the Lago La Plata Formation; this unit hosts an epithermal ore deposit. The Laguna Escondida dacitic porphyry (144.5 ± 1.6 Ma, Jurassic-Cretaceous boundary intruded metasedimentary rocks of the Lago La Plata Formation; this sub-volcanic body can chronologically be linked to the Patagonian Batholith. After the Jurassic volcanic events, a retro-arc basin formed in the eastern sector of the Patagonian Range at about 140-115 Ma (Late Berriasian-Barremian and magmatism ceased during this event. The dating of granitoids (117 ± 1.7 and 99.6 ± 2.8 Ma in the Fontana Lake region confirms a temporal magmatic continuity with the Patagonian Batholith. These dates also are in agreement with the volcanic rocks of the Divisadero Group and epithermal deposits in the region (La Ferrocarrilera deposit. One of the analyzed granitoids (Dedo Chico, 99.6 ± 2.8 Ma has inherited zircon crystals of about 2,100 and 3,410 Ma, in agreement with other previous isotopic evidence for the occurrence of an underlying Precambrian basement in the region.

  3. Yellowstone lake nanoarchaeota.

    Science.gov (United States)

    Clingenpeel, Scott; Kan, Jinjun; Macur, Richard E; Woyke, Tanja; Lovalvo, Dave; Varley, John; Inskeep, William P; Nealson, Kenneth; McDermott, Timothy R

    2013-01-01

    Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park (YNP), where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR) were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels). However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp) demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (71 pyrosequencing reads) was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  4. Yellowstone Lake Nanoarchaeota

    Directory of Open Access Journals (Sweden)

    Scott eClingenpeel

    2013-09-01

    Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  5. Marine incursion: the freshwater herring of Lake Tanganyika are the product of a marine invasion into west Africa.

    Directory of Open Access Journals (Sweden)

    Anthony B Wilson

    Full Text Available The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika's biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25-50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa's Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics.

  6. Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

    Science.gov (United States)

    Zhang, Wenxiang; Ming, Qingzhong; Shi, Zhengtao; Chen, Guangjie; Niu, Jie; Lei, Guoliang; Chang, Fengqin; Zhang, Hucai

    2014-01-01

    Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS) and CaCO3 content), as well as accelerator mass spectrometry (AMS) 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP) were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

  7. Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

    Directory of Open Access Journals (Sweden)

    Wenxiang Zhang

    Full Text Available Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC, total nitrogen (TN, δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS and CaCO3 content, as well as accelerator mass spectrometry (AMS 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

  8. Species spectrum, diversity profile and infection indices of helminth parasite fauna of Chirruh snowtrout, Schizothorax esocinus (Heckel) in lake ecosystems of Kashmir Himalayas-Do similarity and host-parasite associations arise?

    Science.gov (United States)

    Zargar, U R; Chishti, M Z; Yousuf, A R; Ahmad, Fayaz

    2013-09-01

    In order to assess the species richness and diversity profile of helminth parasite fauna in an endemic fish, an investigation was carried out in two urban and two rural lakes of Kashmir. Overall nine species of helminth parasites were observed in four lakes. Of these three were autogenic and six were allogenic. Heteroxenous parasite species were more in number than monoxenous species. Results showed significant differences in heteroxenous / monoxenous ratio between different lakes. Core species (Prevalence > 20) were only found in hypertrophic lake (Anchar Lake). Overall, majority of helminth species were either secondary or satellite species. Prevalence of some helminth parasites showed significant differences in different lakes. In addition mean intensity showed significant differences between autogenic and allogenic parasites (P fauna showed significant differences in species richness and infection indices between different lakes. Diversity profile was higher in Anchar Lake in comparison to other three lakes. The results clearly show that environmental features of lake ecosystems have got an impact on distribution pattern of helminth parasites in S. esocinus. We suggest comparative parasitological study should be taken between different species of fish in order to have a clear picture regarding the species composition of helminth species in this region. Also we need to characterize the species spectrum of parasitic worms in fish of freshwater bodies of this region as well as other similar type of climatic zones because parasite fauna is an integral part of the inventory of biodiversity and as possible regulators of host populations in aquatic ecosystems.

  9. Using the MESH modelling system for hydrological ensemble forecasting of the Laurentian Great Lakes at the regional scale

    Directory of Open Access Journals (Sweden)

    A. Pietroniro

    2006-08-01

    Full Text Available Environment Canada has been developing a community environmental modelling system (Modélisation Environmentale Communautaire – MEC, which is designed to facilitate coupling between models focusing on different components of the earth system. The ultimate objective of MEC is to use the coupled models to produce operational forecasts. MESH (MEC – Surface and Hydrology, a configuration of MEC currently under development, is specialized for coupled land-surface and hydrological models. To determine the specific requirements for MESH, its different components were implemented on the Laurentian Great Lakes watershed, situated on the Canada–U.S. border. This experiment showed that MESH can help us better understand the behaviour of different land-surface models, test different schemes for producing ensemble streamflow forecasts, and provide a means of sharing the data, the models and the results with collaborators and end-users. This modelling framework is at the heart of a testbed proposal for the Hydrologic Ensemble Prediction Experiment (HEPEX which should allow us to make use of the North American Ensemble Forecasting System (NAEFS to improve streamflow forecasts of the Great Lakes tributaries, and demonstrate how MESH can contribute to a Community Hydrologic Prediction System (CHPS.

  10. Spatial distribution and pollution assessment of mercury in sediments of Lake Taihu, China

    Institute of Scientific and Technical Information of China (English)

    Chunxiao Chen; Binghui Zheng; Xia Jiang; Zheng Zhao; Yuzhu Zhan; Fengjiao Yi; Jiaying Ren

    2013-01-01

    Spatial distribution patterns of total mercury (THg) in 36 surficial sediment samples representing five regions of Lake Taihu were assessed using the ArcGis geostatistical analyst module.The pollution levels of THg were also evaluated from the same five lake regions.Concentrations of THg were in a ranged of 23-168 ng/g (mean 55 ng/g) in surfical sediments,which was significantly higher than those established baseline levels of the lake.Results of THg indicated that the northern region exhibited notably higher values,the bay regions showed elevated values relative to open areas,and the lakeside regions were higher than those observed in the central area.Lake Taihu suffered moderate to high Hg pollution,and expressed clear Hg enrichment status according to monomial pollution index Igeo and human activity factors.The concentrations of THg in the surticial sediments of Lake Taihu showed moderate-strong variation (coefficient of variation 52%).Geostatistical analysis indicated a weak spatial self-correlation,suggesting the contamination of Hg in Lake Taihu is primarily the result of anthropogenic activities.

  11. Lake Sediment Records as an Indicator of Holocene Fluctuations of Quelccaya Ice Cap, Peru and Regional Climate

    Science.gov (United States)

    Stroup, J. S.; Kelly, M. A.; Lowell, T. V.; Beal, S. A.; Smith, C. A.; Baranes, H. E.

    2012-12-01

    The past fluctuations of Quelccaya Ice Cap, (QIC; 13°S, 70°W, 5200 m asl) located in the southeastern Peruvian Andes, provide a record of tropical climate since the last glacial-interglacial transition. A detailed surficial geomorphic record of past glacial extents developed over the last several decades (e.g. Mercer and Palacios 1977; Buffen et al. 2009; Kelly et al. 2012 accepted) demonstrates that QIC is a dynamic glacial system. These records show that the ice cap was larger than present and retreating by ~11,500 yr BP, and smaller than present between ~7,000 and ~4,600 yr BP. The most recent advance occurred during the late Holocene (Little Ice Age;LIA), dated with 10Be surface exposure ages (510±90 yrs (n = 8)) (Stroup et al. in prep.). This overrode earlier deposits obscuring a complete Holocene record; we aim to address the gaps in glacial chronology using the sedimentary record archived in lakes. We retrieved two sets cores (8 and 5 m-long) from Laguna Challpacocha (13.91°S, 70.86°W, 5040 m asl), a lake that currently receives meltwater from QIC. Four radiocarbon ages from the cores suggest a continuous record dating to at least ~10,500 cal. yr BP. Variations in magnetic susceptibility, percent organic and inorganic carbon, bulk density, grayscale and X-ray fluorescence chemistry indicate changes in the amount of clastic sediment deposition. We interpret clastic sediments to have been deposited from ice cap meltwater, thus indicating more extensive ice. Clastic sediments compose the top of the core from 4 to 30 cm depth, below there is a sharp transition to organic sediments radiocarbon dated to (500±30 and 550±20 cal. yr BP). The radiocarbon ages are similar to the 10Be dated (LIA) glacial position. At least three other clastic units exist in the core; dating to ~2600-4300, ~4800-7300 and older then ~10,500 cal. yr BP based on a linear age model with four radiocarbon dates. We obtained two, ~4 m long, cores from Laguna Yanacocha (13.95°S,70.87

  12. Degradation of pyrene and characterization of Saccharothrix sp. PYX-6 from the oligotrophic Tianchi Lake in Xinjiang Uygur Autonomous Region, China

    Institute of Scientific and Technical Information of China (English)

    HU Yuting; REN Fenghua; ZHOU Peijin; XIA Min; LIU Shuangjiang

    2003-01-01

    Bacterial strain PYX-6 that utilizes anthracene, phenanthrene, or pyrene for carbon and energy sources for growth was isolated from a non-polluted lake (Tianchi Lake) in Xinjiang Uygur Autonomons Region of China. Its morphology, physiological and biochemical properties, cell wall pattern and G+C mol% content of DNA molecules were characterized. The 16S rRNA gene of strain PYX-6 was sequenced and analyzed for similarities to related bacterial species. Results indicated that strain PYX-6 is a member of the Genus Saccharothrix, and the strain was named Saccharothrix sp. PYX-6. When pyrene was the sole carbon source in cultural medium, the strain PYX-6 assimilated pyrene for growth and 0.005% of yeast extract stimulated pyrene degradation and assimilation. The optimal pH of cultural medium and the optimal shaking frequency during cultivation were 6-8 and 200 r/m, respectively. It was found that the disappearance of pyrene in medium occurred before significant growth of strain PYX-6 took place. Phthalic acid, benzylacetic acid, and benzylpropenoic acid were detected as catabolic intermediates during pyrene degradation with mass spectroscopy and this result indicated that Saccharothrix sp. PYX-6 adopted a pathway that is different from the pathway of the previously reported pyrene-degrading Mycobacterium sp. PYR-1.

  13. IMPACT OF THE ATATÜRK DAM LAKE ON AGRO-METEOROLOGICAL ASPECTS OF THE SOUTHEASTERN ANATOLIA REGION USING REMOTE SENSING AND GIS ANALYSIS

    Directory of Open Access Journals (Sweden)

    O. Ozcan

    2012-07-01

    Full Text Available The Atatürk Dam is the fourth largest clay-cored rock fill dam in the world. It was constructed on the Euphrates River located in semi-arid Southeastern Turkey in the 1980s as the central component of a large-scale regional development project for the Southeastern Anatolia region (referred to as GAP. The construction began in 1983 and was completed in 1990. The dam and the hydroelectric power plant, which went into service after filling up the reservoir was accomplished in 1992. The Atatürk Dam, which has a height of 169 m, a total storage capacity of 48.7 million m3, and a surface area of about 817 km2 plays an important role in the development of Turkey's energy and agriculture sectors. In this study, the spatial and temporal impacts of the Atatürk Dam on agro-meteorological aspects of the Southeastern Anatolia region have been investigated. Change detection and environmental impacts due to water-reserve changes in Atatürk Dam Lake have been determined and evaluated using multi-temporal Landsat satellite imageries and meteorological datasets within a period of 1984 to 2011. These time series have been evaluated for three time periods. Dam construction period constitutes the first part of the study. Land cover/use changes especially on agricultural fields under the Atatürk Dam Lake and its vicinity have been identified between the periods of 1984 to 1992. The second period comprises the 10-year period after the completion of filling up the reservoir in 1992. At this period, Landsat and meteorological time-series analyses are examined to assess the impact of the Atatürk Dam Lake on selected irrigated agricultural areas. For the last 9-year period from 2002 to 2011, the relationships between seasonal water-reserve changes and irrigated plains under changing climatic factors primarily driving vegetation activity (monthly, seasonal, and annual fluctuations of rainfall rate, air temperature, humidity on the watershed have been investigated

  14. Analysis of ERS 1 synthetic aperture radar data of frozen lakes in northern Montana and implications for climate studies

    Science.gov (United States)

    Hall, Dorothy K.; Fagre, Daniel B.; Klasner, Fritz; Linebaugh, Gregg; Liston, Glen E.

    1994-01-01

    Lakes that freeze each winter are good indicators of regional climate change if key parameters, such as freeze-up and breakup date and maximum ice thickness, are measured over a decade-scale time frame. Synthetic aperture radar (SAR) satellite data have proven to be especially useful for measurement of climatologically significant parameters characteristic of frozen lakes. In this paper, five lakes in Glacier National Park, Montana, have been studied both in the field and using Earth Remote-Sensing Satellite (ERS) 1 SAR data during the 1992-1993 winter. The lakes are characterized by clear ice, sometimes with tubular or rounded bubbles, and often with a layer of snow ice on top of the clear ice. They are also often snow covered. Freeze-up is detected quite easily using ERS 1 SAR data as soon as a thin layer of ice forms. The effect of snow ice on the backscatter is thought to be significant but is, as yet, undetermined. On the five lakes studied, relative backscatter was found to increase with ice thickness until a maximum was reached in February. Breakup, an often ill-defined occurrence, is difficult to detect because surface water causes the SAR signal to be absorbed, thus masking the ice below. Comparison of the bubble structure of thaw lakes in northern Alaska with lakes in northern Montana has shown that the ice structure is quite different, and this difference may contribute to differential SAR signature evolution in the lakes of the two areas.

  15. Airborne Hyperspectral Sensing of Monitoring Harmful Algal Blooms in the Great Lakes Region: System Calibration and Validation

    Science.gov (United States)

    Lekki, John; Anderson, Robert; Avouris, Dulcinea; Becker, RIchard; Churnside, James; Cline, Michael; Demers, James; Leshkevich, George; Liou, Larry; Luvall, Jeffrey; Ortiz, Joseph; Royce, Anthony; Ruberg, Steve; Sawtell, Reid; Sayers, Michael; Schiller, Stephen; Shuchman, Robert; Simic, Anita; Stuart, Dack; Sullivan, Glenn; Tavernelli, Paul; Tokars, Roger; Vander Woude, Andrea

    2017-01-01

    Harmful algal blooms (HABs) in Lake Erie have been prominent in recent years. The bloom in 2014 reached a severe level causing the State of Ohio to declare a state of emergency. At that time NASA Glenn Research Center was requested by stakeholders to help monitor the blooms in Lake Erie. Glenn conducted flights twice a week in August and September and assembled and distributed the HAB information to the shoreline water resource managers using its hyperspectral imaging sensor (in development since 2006), the S??3 Viking aircraft, and funding resources from the NASA Headquarters Earth Science Division. Since then, the State of Ohio, National Oceanic and Atmospheric Administration (NOAA), and U.S. Environmental Protection Agency (EPA) have elevated their funding and activities for observing, monitoring, and addressing the root cause of HABs. Also, the communities and stakeholders have persistently requested NASA Glenn??s participation in HAB observation. Abundant field campaigns and sample analyses have been funded by Ohio and NOAA, which provided a great opportunity for NASA to advance science and airborne hyperspectral remote sensing economically. Capitalizing on this opportunity to advance the science of algal blooms and remote sensing, NASA Glenn conducted the Airborne Hyperspectral Observation of harmful algal blooms campaign in 2015 that was, in many respects, twice as large as the 2014 campaign. Focusing mostly on Lake Erie, but also including other small inland lakes and the Ohio River, the campaign was conducted in partnership with a large number of partners specializing in marine science and remote sensing. Airborne hyperspectral observation of HABs holds promise to distinguish potential HABs from nuisance blooms, determine their concentrations, and delineate their movement in an augmented spatial and temporal resolution and under clouds??all of which are excellent complements to satellite observations. Working with collaborators at several Ohio and Michigan

  16. Field scale interaction and nutrient exchange between surface water and shallow groundwater in the Baiyang Lake region, North China Plain

    DEFF Research Database (Denmark)

    Brauns, Bentje; Bjerg, Poul Løgstrup; Song, Xianfang

    2016-01-01

    and groundwater, (b) quantify nutrient loadings, and (c) identify major nutrient removal pathways by using qualitative and quantitative methods, including the geochemical model PHREEQC) a one-year study at a wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping system in the Baiyang Lake area...... vertical transport from the field surface (up to 134.8mg/L NO3-N in soil water). Results from a conceptual model show an excess nitrogen input of about 320kg/ha/a. Nevertheless, both nitrogen species were only detected at low concentrations in shallow groundwater, averaging at 3.6mg/L NH4-N and 1.8mg/L NO3...

  17. Variation of phytoplankton functional groups modulated by hydraulic controls in Hongze Lake, China.

    Science.gov (United States)

    Tian, Chang; Pei, Haiyan; Hu, Wenrong; Hao, Daping; Doblin, Martina A; Ren, Ying; Wei, Jielin; Feng, Yawei

    2015-11-01

    Hongze Lake is a large, shallow, polymictic, eutrophic lake in the eastern China. Phytoplankton functional groups in this lake were investigated from March 2011 to February 2013, and a comparison was made between the eastern, western, and northern regions. The lake shows strong fluctuations in water level caused by monsoon rains and regular hydraulic controls. By application of the phytoplankton functional group approach, this study aims to investigate the spatial and temporal dynamics and analyze their influencing factors. Altogether, 18 functional groups of phytoplankton were identified, encompassing 187 species. In order to seek the best variable describing the phytoplankton functional group distribution, 14 of the groups were analyzed in detail using redundancy analysis. Due to the turbid condition of the lake, the dominant functional groups were those tolerant of low light. The predominant functional groups in the annual succession were D (Cyclotella spp. and Synedra acus), T (Planctonema lauterbornii), P (Fragilaria crotonensis), X1 (Chlorella vulgaris and Chlorella pyrenoidosa), C (Cyclotella meneghiniana and Cyclotella ocellata), and Y (Cryptomonas erosa). An opposite relationship between water level and the biomass of predominant groups was observed in the present study. Water level fluctuations, caused by monsoonal climate and artificial drawdown, were significant factors influencing phytoplankton succession in Hongze Lake, since they alter the hydrological conditions and influence light and nutrient availability. The clearly demonstrated factors, which significantly influence phytoplankton dynamics in Hongze Lake, will help government manage the large shallow lakes with frequent water level fluctuations.

  18. Enhanced ice sheet growth in Eurasia owing to adjacent ice-dammed lakes.

    Science.gov (United States)

    Krinner, G; Mangerud, J; Jakobsson, M; Crucifix, M; Ritz, C; Svendsen, J I

    2004-01-29

    Large proglacial lakes cool regional summer climate because of their large heat capacity, and have been shown to modify precipitation through mesoscale atmospheric feedbacks, as in the case of Lake Agassiz. Several large ice-dammed lakes, with a combined area twice that of the Caspian Sea, were formed in northern Eurasia about 90,000 years ago, during the last glacial period when an ice sheet centred over the Barents and Kara seas blocked the large northbound Russian rivers. Here we present high-resolution simulations with an atmospheric general circulation model that explicitly simulates the surface mass balance of the ice sheet. We show that the main influence of the Eurasian proglacial lakes was a significant reduction of ice sheet melting at the southern margin of the Barents-Kara ice sheet through strong regional summer cooling over large parts of Russia. In our simulations, the summer melt reduction clearly outweighs lake-induced decreases in moisture and hence snowfall, such as has been reported earlier for Lake Agassiz. We conclude that the summer cooling mechanism from proglacial lakes accelerated ice sheet growth and delayed ice sheet decay in Eurasia and probably also in North America.

  19. Investigation of the dramatic changes in lake level of the Bosten Lake in northwestern China

    Science.gov (United States)

    Guo, Mengjing; Wu, Wei; Zhou, Xiaode; Chen, Yongmin; Li, Jing

    2015-01-01

    Bosten Lake, located in the arid region of northwest China, is the largest inland freshwater lake in China. Water resources in Bosten Lake are of great importance for the regional drinking water supply, agricultural irrigation, and economic development of Xinjiang province. In this study, the dynamics of the lake level in Bosten Lake were investigated from 1956 to 2010. We found that the lake level experienced three different periods of change due to the combined influences of climate variation and human activities. Generally, the lake level has shown a significant downward trend since the first observation started in 1956 and dropped to its lowest level in 1987. Thereafter, the lake level presented a continuous upward trend and rose to its highest value in 2002. Then, the level decreased dramatically from 2002 to 2010. A water balance model and the climate elasticity method were used to estimate the reasons for the lake level changes of Bosten Lake. The results showed that an increase in lake evaporation led to the continuous decrease in lake level from 1958 to 1987. Then, human-controlled lake outflow and increasing lake inflow together led to the increase in lake level from 1988 to 2002. During 2003 to 2010, the emergency project of transferring water to Tarim River led to the increase in lake outflow, while the lake inflow obviously decreased because of a decrease in precipitation. These factors resulted in a sharp decrease in the lake level from 2003 to 2010. The changes in lake level indicate changes in available water resources from Bosten Lake. This reason for the analysis of the change in lake level in this study is to support the water resources management of Bosten Lake.

  20. Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in Eastern Canadian Boreal Shield lakes

    Directory of Open Access Journals (Sweden)

    P. Glaz

    2015-06-01

    Full Text Available Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM were measured over a three-year period in eight Eastern Boreal Shield lakes: four lakes were studied before, one and two years after forest harvesting (perturbed lakes and compared with four undisturbed reference lakes (unperturbed lakes sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering one year before and one year after the perturbation only. At one year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~15 mg C L−1 compared to 12.5 mg C L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterised with spectroscopic techniques. Multivariate statistical analysis showed lakes to be significantly different one year after the perturbation. These results confirm an impact of forestry activities one year after the perturbation. However, this effect seems to be mitigated two years after, indicating that the system shows high resilience and may be able to return to its original condition.

  1. The management of clear cell sarcoma

    NARCIS (Netherlands)

    Kuiper, DR; Hoekstra, HJ; Veth, RPH; Wobbes, T

    2003-01-01

    Clear cell sarcoma is a rare soft tissue tumour, constituting approximately 1% of all soft tissue sarcomas. Prognosis is reported to be poor due to the great propensity to metastasise regionally and distantly. In this paper, we report the surgical experience of two university hospitals. Both disease

  2. Satellite microwave assessment of Northern Hemisphere lake ice phenology from 2002 to 2015

    Science.gov (United States)

    Du, Jinyang; Kimball, John S.; Duguay, Claude; Kim, Youngwook; Watts, Jennifer D.

    2017-01-01

    A new automated method enabling consistent satellite assessment of seasonal lake ice phenology at 5 km resolution was developed for all lake pixels (water coverage ≥ 90 %) in the Northern Hemisphere using 36.5 GHz H-polarized brightness temperature (Tb) observations from the Advanced Microwave Scanning Radiometer for EOS and Advanced Microwave Scanning Radiometer 2 (AMSR-E/2) sensors. The lake phenology metrics include seasonal timing and duration of annual ice cover. A moving t test (MTT) algorithm allows for automated lake ice retrievals with daily temporal fidelity and 5 km resolution gridding. The resulting ice phenology record shows strong agreement with available ground-based observations from the Global Lake and River Ice Phenology Database (95.4 % temporal agreement) and favorable correlations (R) with alternative ice phenology records from the Interactive Multisensor Snow and Ice Mapping System (R = 0.84 for water clear of ice (WCI) dates; R = 0.41 for complete freeze over (CFO) dates) and Canadian Ice Service (R = 0.86 for WCI dates; R = 0.69 for CFO dates). Analysis of the resulting 12-year (2002-2015) AMSR-E/2 ice record indicates increasingly shorter ice cover duration for 43 out of 71 (60.6 %) Northern Hemisphere lakes examined, with significant (p regional trends toward earlier ice melting for only five lakes. Higher-latitude lakes reveal more widespread and larger trends toward shorter ice cover duration than lower-latitude lakes, consistent with enhanced polar warming. This study documents a new satellite-based approach for rapid assessment and regional monitoring of seasonal ice cover changes over large lakes, with resulting accuracy suitable for global change studies.

  3. Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

    Science.gov (United States)

    Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

    2016-11-01

    The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

  4. Multi-century lake area changes in the Southern Altiplano: a tree-ring-based reconstruction

    Science.gov (United States)

    Morales, M. S.; Carilla, J.; Grau, H. R.; Villalba, R.

    2015-09-01

    Size fluctuations in endorheic lakes in northwestern Argentina (NWA) and southwestern Bolivia (SWB) are very sensitive to basin hydrological balances, and consequently, very vulnerable to deleterious effects from climatic changes. The management of these water resources and their biodiversity requires a comprehensive knowledge of their natural variability over multiple timescales. In this study, we present a multi-century reconstruction of past lake-area fluctuations in NWA and SWB. The evidence used to develop and validate this reconstruction includes satellite images and a century-long tree-ring record from P. tarapacana. Inter-annual fluctuations in lake area of nine lakes were quantified based on Landsat satellite images over the period 1975 to 2009. A regional P. tarapacana tree-ring chronology, composite from two sampling sites, was used as predictors in a regression model to reconstruct the mean annual (January-December) lake area from the nine lakes. The reconstruction model captures 62 % of the total variance in lake-area fluctuations and shows adequate levels of cross-validation. This high-resolution reconstruction covers the past 601 years and characterizes the occurrence of annual to multi-decadal lake area fluctuations and its main oscillation modes of variability. Our reconstruction points out that the late 20th century decrease in lake area was exceptional over the period 1407-2007; a persistent negative trend in lake area is clear in the reconstruction and consistent with glacier retreat and other climate proxies from the Altiplano and the tropical Andes. Since the mid 1970s, the Vilama-Coruto lake system recorded an accelerated decrease in area consistent with an increasing recurrence of extremely small lake-area events. Throughout the 601 years, the reconstruction provides valuable information about spatial and temporal stabilities of the relationships between changes in lake area, ENSO, and PDO, highlighting the Pacific influence over most modes

  5. Dynamic Assessment on Regional Eco-environmental Quality Using AHP-Statistics Model——A Case Study of Chaohu Lake Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An indicator system closely connected with eco-environment, in which indicator involves in such fields as society, economy, resources, environment and ecology, is first proposed for eco-environmental quality assessment.Then, a hierarchical model with four levels is established by virtue of these indicators and attributes. In the model,weights of indicators and attributes are determined by combining Delphi method with the Analytic Hierarchy Process (AHP) and a statistic method is used to eliminate the influences arising from the differences in dimension and magnitude of indicators. On these grounds, an AHP-statistics model is provided for regional eco-environmental quality assessment. As a case, such AHP-statistics model is utilized in the dynamic analysis of regional eco-environmental assessment in Chaohu Lake basin. Study results show that natural environmental quality in the watershed was in the declining state while social environmental quality was in a markedly improved situation from 1996, and the synthetic eco-environmental quality was gradually and slowly improved under the common influences of both natural and social environmental factors. Example of application testified the capacities of above methodology to evaluate the real and dynamic state of regional eco-environmental quality.

  6. Inferring local to regional changes in forest composition from Holocene macrofossils and pollen of a small lake in central Upper Michigan

    Science.gov (United States)

    Jackson, Stephen T.; Booth, Robert K.; Reeves, Kelly; Andersen, Jennifer Jewell; Minckley, Thomas A.; Jones, Rachel A.

    2014-08-01

    Vegetational response to climatic change involves processes of population and community dynamics within local stands, which scale up to landscape-level changes in vegetation composition and broad-scale changes in species distributions. Understanding these dynamics poses a critical challenge to paleoecological explanation, because of the broad range of scales at which these dynamics take place and interact. We present an 8600-year paleoecological record of local and regional changes in forest composition from a small (2.6 ha) lake in central Upper Michigan. Plant macrofossils provide a spatially precise record of local forest composition, while pollen data provide a spatially integrated record of regional vegetational changes. Temporal patterns among different macrofossil types within species show overall coherence, indicating that changes in macrofossil abundance generally record changes in local tree abundance. Temporal patterns in macrofossil sequences correspond to patterns in pollen sequences, indicating that local changes contributed to the large-scale changes in the surrounding region. The pollen and macrofossil records show nearly continuous turnover in vegetation composition throughout the past 8600 years; the longest period without major compositional change was ca 1600 years, and dynamics at multidecadal to multicentennial scales are observed during many periods. Coordinated application of temporally precise sequences of pollen and macrofossil data at multiple sites can support inferences concerning vegetation dynamics at multiple spatial and temporal scales, and test mechanistic hypotheses.

  7. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  8. Investigation into avian mortality in the Playa Lakes region of southeastern New Mexico: Final Report - June 1997

    Science.gov (United States)

    Dein, F. Joshua; Baeten, Laurie A.; Moore, Melody K.; Samuel, Michael D.; Miller, Paul D.; Murphy, Christopher; Sissler, Steven; Jeske, Clinton W.; Jehl, Joseph R.; Yaeger, J. S.; Bauer, B.; Mahoney, Shiela A.

    1997-01-01

    This Final Report is a review of work on a cooperative study undertaken by the USGS Biological Resources Division's National Wildlife Health Center (NWHC) and National Wetlands Research Center (NWRC; formerly the Southern Science Center) from 1994 through 1997. The study was initiated at the request of the Bureau of Land Management (BLM), through a request to the former National Biological Service. The Southeastern New Mexico Playa Lakes Coordinating Committee (SENMPLCC) played an important role in outlining the research needs. The initial Study Plan document, which outlines the background, objectives and methods for the first two years is available as Appendix 1. A letter indicating modifications to the Study Plan was sent to the SENMPLCC chair on April 25,1995, and is Appendix 2. An Interim Report, covering this work was completed and submitted in September 1995. The Literature Review section of the study was completed and presented to SENMPLCC in August, 1995. Following SENMPLCC review, NWHC was asked to develop a series of questions that could be posed from information gained in the initial phase (Appendix 3). The NWHC and NWRC were then directed to begin work to answer the top three questions, within the available fiscal resources. NWRC could continue with work outlined under the original Study Plan (Appendix 1), however an additional Study Plan for experiments performed by NWHC and collaborators and is available as Appendix 4.

  9. 洞庭湖生态经济区生态功能区划研究%Eco-function regionalization for Dongting Lake Eco-economic Zone

    Institute of Scientific and Technical Information of China (English)

    李姣; 张灿明; 罗佳

    2013-01-01

    With access to general profile of Dongting Lake Eco-economic Zone based on the analysis of regional natural features and human-induced factors,the newly emerging changes concerning the lacustrine wetland ecosystem of the zone were analyzed,on which the basic principles were put forward for the eco-function regionalizafon of the region,and the bases for the lake regions eco-functional regionalization were presented according to the relevant intonational conventions and domestic national laws and regulations.On this basis,the eco-economical regionalization for Dongting Lake Eco-economic Zone was divided into four first grade ecological zones according to the natural attributes and leading service types.The four first grade ecological zone was divided into ten ecological subzones,and re-divided into thirty two eco-function zones.An eco-function division map was drawn out by adopting GIS spatial overlay techniques,with the map,the differentiated geographic setting ranges,function orientations,keys of conservation and construction of the four eco-zones can be explained,which provides a scientific support for coordinating development between eco-coustruction and social and economic progress.%基于洞庭湖生态经济区自然条件与人类活动影响因素,概述了湖区基本状况,并主要分析了近些年该区湖泊湿地生态系统出现的新变化.提出湖区生态功能区划的基本原则,并根据湖区生态系统空间特征、生态敏感性、生态系统服务功能、相关国际公约与国内法律法规等,分析了湖区生态功能区划依据.在此基础上,根据湖区生态系统自然属性和主导服务功能类型,将洞庭湖生态经济区划分为4个一级生态区;根据一级生态区的生态系统服务功能的重要性、亟待保护的内容和程度、生态需求与修复目标的区域差异性等,将一级生态区划分为10个生态亚区和32个生态功能区.采用地理信息系统的空间叠置法,绘制了

  10. Computer simulation of phosphorus cycling in the sediment-water system of eutrophic lakes

    Energy Technology Data Exchange (ETDEWEB)

    Hannula, T.A.; Rock, C.A.

    1983-08-01

    It has become increasingly evident that the release of phosphorus from the sediments of eutrophic lakes is a major factor in the excessive productivity of these lakes. Using the diagenic partial differential equations which model the sediment processes of lakes and oceans, a computer simulation model has been developed to study the P dynamics in lake sediments. The model allows both time and depth variation of the key equation parameters. The model clearly shows that the upper 10 cm of sediment is the main region of activity. The model generates summary tables and 3D plots of key variables over a year's simulation. Data from L. Sebasticook, Newport, Maine are used to test the model.

  11. Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

    Science.gov (United States)

    Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

    2016-01-01

    This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems.

  12. Endocrine disrupting alkylphenolic chemicals and other contaminants in wastewater treatment plant effluents, urban streams, and fish in the Great Lakes and Upper Mississippi River Regions

    Science.gov (United States)

    Barber, Larry B.; Loyo-Rosales, Jorge E.; Rice, Clifford P.; Minarik, Thomas A.; Oskouie, Ali K.

    2015-01-01

    Urban streams are an integral part of the municipal water cycle and provide a point of discharge for wastewater treatment plant (WWTP) effluents, allowing additional attenuation through dilution and transformation processes, as well as a conduit for transporting contaminants to downstream water supplies. Domestic and commercial activities dispose of wastes down-the-drain, resulting in wastewater containing complex chemical mixtures that are only partially removed during treatment. A key issue associated with WWTP effluent discharge into streams is the potential to cause endocrine disruption in fish. This study provides a long-term (1999-2009) evaluation of the occurrence of alkylphenolic endocrine disrupting chemicals (EDCs) and other contaminants discharged from WWTPs into streams in the Great Lakes and Upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio). The Greater Metropolitan Chicago Area Waterways, Illinois, were evaluated to determine contaminant concentrations in the major WWTP effluents and receiving streams, and assess the behavior of EDCs from their sources within the sewer collection system, through the major treatment unit processes at a WWTP, to their persistence and transport in the receiving stream. Water samples were analyzed for alkylphenolic EDCs and other contaminants, including 4-nonylphenol (NP), 4-nonylphenolpolyethoxylates (NPEO), 4-nonylphenolethoxycarboxylic acids (NPEC), 4-tert-octylphenol (OP), 4-tert-octylphenolpolyethoxylates (OPEO), bisphenol A, triclosan, ethylenediaminetetraacetic acid (EDTA), and trace elements. All of the compounds were detected in all of the WWTP effluents, with EDTA and NPEC having the greatest concentrations. The compounds also were detected in the WWTP effluent dominated rivers. Multiple fish species were collected from river and lake sites and analyzed for NP, NPEO, NPEC, OP, and OPEO. Whole-body fish tissue analysis indicated widespread occurrence of alkylphenolic compounds

  13. Detecting Precontact Anthropogenic Microtopographic Features in a Forested Landscape with Lidar: A Case Study from the Upper Great Lakes Region, AD 1000-1600.

    Science.gov (United States)

    Howey, Meghan C L; Sullivan, Franklin B; Tallant, Jason; Kopple, Robert Vande; Palace, Michael W

    2016-01-01

    Forested settings present challenges for understanding the full extent of past human landscape modifications. Field-based archaeological reconnaissance in forests is low-efficiency and most remote sensing techniques are of limited utility, and together, this means many past sites and features in forests are unknown. Archaeologists have increasingly used light detection and ranging (lidar), a remote sensing tool that uses pulses of light to measure reflecting surfaces at high spatial resolution, to address these limitations. Archaeology studies using lidar have made significant progress identifying permanent structures built by large-scale complex agriculturalist societies. Largely unaccounted for, however, are numerous small and more practical modifications of landscapes by smaller-scale societies. Here we show these may also be detectable with lidar by identifying remnants of food storage pits (cache pits) created by mobile hunter-gatherers in the upper Great Lakes during Late Precontact (ca. AD 1000-1600) that now only exist as subtle microtopographic features. Years of intensive field survey identified 69 cache pit groups between two inland lakes in northern Michigan, almost all of which were located within ~500 m of a lakeshore. Applying a novel series of image processing techniques and statistical analyses to a high spatial resolution DTM we created from commercial-grade lidar, our detection routine identified 139 high potential cache pit clusters. These included most of the previously known clusters as well as several unknown clusters located >1500 m from either lakeshore, much further from lakeshores than all previously identified cultural sites. Food storage is understood to have emerged regionally as a risk-buffering strategy after AD 1000 but our results indicate the current record of hunter-gatherer cache pit food storage is markedly incomplete and this practice and its associated impact on the landscape may be greater than anticipated. Our study also

  14. Media Language, Clear or Obscure

    DEFF Research Database (Denmark)

    Jakobsen, Bjarne le Fevre; Ejstrup, Michael

    2015-01-01

    Abstract— Be clear, not obscure. One of the four maxims for optimal communication is that it is essential to develop proficiency in being concise and clear. The question is whether this is really a good idea in all contexts. There is some evidence to the contrary. Undoubtedly, we have many contex...... for the survival of free speech....... growth in diversity, means that media need to be very cognizant of the stringency with which they handle the advice to be linguistically clear and concise. The need to pay great attention to situational awareness is highly visible and intrusive. Attention to situational awareness seems to be crucial...

  15. Microbiology of Lonar Lake and other soda lakes.

    Science.gov (United States)

    Antony, Chakkiath Paul; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-03-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence.

  16. Field scale interaction and nutrient exchange between surface water and shallow groundwater in the Baiyang Lake region, North China Plain.

    Science.gov (United States)

    Brauns, Bentje; Bjerg, Poul L; Song, Xianfang; Jakobsen, Rasmus

    2016-07-01

    Fertilizer input for agricultural food production, as well as the discharge of domestic and industrial water pollutants, increases pressures on locally scarce and vulnerable water resources in the North China Plain. In order to: (a) understand pollutant exchange between surface water and groundwater, (b) quantify nutrient loadings, and (c) identify major nutrient removal pathways by using qualitative and quantitative methods, including the geochemical model PHREEQC) a one-year study at a wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping system in the Baiyang Lake area in Hebei Province, China, was undertaken. The study showed a high influence of low-quality surface water on the shallow aquifer. Major inflowing pollutants into the aquifer were ammonium and nitrate via inflow from the adjacent Fu River (up to 29.8mg/L NH4-N and 6.8mg/L NO3-N), as well as nitrate via vertical transport from the field surface (up to 134.8mg/L NO3-N in soil water). Results from a conceptual model show an excess nitrogen input of about 320kg/ha/a. Nevertheless, both nitrogen species were only detected at low concentrations in shallow groundwater, averaging at 3.6mg/L NH4-N and 1.8mg/L NO3-N. Measurement results supported by PHREEQC-modeling indicated cation exchange, denitrification, and anaerobic ammonium oxidation coupled with partial denitrification as major nitrogen removal pathways. Despite the current removal capacity, the excessive nitrogen fertilization may pose a future threat to groundwater quality. Surface water quality improvements are therefore recommended in conjunction with simultaneous monitoring of nitrate in the aquifer, and reduced agricultural N-inputs should be considered.

  17. Great Lakes Restoration Initiative Great Lakes Mussel Watch(2009-2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Following the inception of the Great Lakes Restoration Initiative (GLRI) to address the significant environmental issues plaguing the Great Lakes region, the...

  18. Biomass removal, retention, and costs associated with biomass harvesting in the partial harvest systems of Ontario's Great Lakes-Saint Lawrence forest region : preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, D. [Toronto Univ., ON (Canada). Faculty of Forestry

    2010-07-01

    Recent bioenergy policy developments in Ontario have increased interest in forest biomass supply research. Biomass harvested from clearcut and partial harvest system in the Great Lakes-Saint Lawrence (GLSL) region can be used to supply centralized pellet plants or directly to forest mill-based conversion facilities for electricity generation. Preliminary results from a biomass harvesting trial conducted in the GLSL have confirmed that whole-tree harvesting (WTH) and the removal of skid trail results in increased biomass removal and improved operational productivity relative to conventional cut-to-length methods. Biomass removals can be increased through the imposition of smaller minimum topping diameters and the harvesting of unmerchantable trees. The results of a study conducted to evaluate the difference between conventional and biomass harvesting in a shelterwood and selection system in the GLSL has indicated that increases in the amount of firewood and small, irregular blocks of wood recovered from biomass harvests are negligible compared with conventional harvesting practices. Biomass harvesting trials are currently being conducted to determine biomass removal and operational productivity calculations for determining the overall economic feasibility of biomass harvesting for energy in the region.

  19. A regional inventory of the landslide processes and the elements at risk on the Rift flanks west of Lake Kivu (DRC)

    Science.gov (United States)

    Maki Mateso, Jean-Claude; Monsieurs, Elise; Jacobs, Liesbet; Bagalwa Mateso, Luc; Fiama Bondo, Silvanos; Delvaux, Damien; Albino, Fabien; Kervyn, François; Dewitte, Olivier

    2016-04-01

    The Rift flanks west of Lake Kivu (DRC) are one of the Congolese regions most affected by fatal landslides. However, information on the distribution of these processes and their impact on society is still lacking. Here we present a first regional landslide inventory and the associated elements at risk. The inventory was conducted in an area of 5,700 km² in three administrative territories between the cities of Bukavu and Goma. The region is one of the most densely populated area of DRC with a density of up to 200 persons/km². The approach for the inventory relies on visual analysis of Google Earth imagery and a 5 m resolution DEM that we produced from TanDEM-X interferometry. Field validation was performed in target places accounting for 5% of the study area. More than 2,000 landslides were mapped and distinction was made between deep and shallow, and slide and flow processes. Average landslide area is 6 ha (max. = 430 ha). Geomorphological analysis of landslide distribution shows topographic, lithologic, climatic and seismic controls. For 600 randomly-selected landslides, elements at risk (house, road, cultivated land, river) were inventoried in the areas affected and potentially affected by the instabilities; 10% of the landslides are inhabited and 25% do not present any risk. Numerous landslides have caused direct and indirect damage in recent years. In some places, the impact of mining activities on slope stability can be important. Google Earth was the only way to locate the recent shallow failures triggered by known extreme rainfall events. This inventory is a first step towards the understanding of the landslide processes in the region. Further studies are needed to complete and validate the information, to better infer about the triggers, and to compute susceptibility and risk maps.

  20. Response of alpine lakes and soils to changes in acid deposition: the MAGIC model applied to the Tatra Mountain region, Slovakia-Poland

    Directory of Open Access Journals (Sweden)

    Josef VESELÝ

    2004-02-01

    Full Text Available A dynamic process-based model of surface water acidification, MAGIC, was applied to 31 representative alpine lakes in the Tatra Mountains (~50% of all alpine lakes >0.3 ha in the lake-district. The model was calibrated to observed lake chemistry for the period 1980-2002. Surface water and soil chemistry were reconstructed from 1860 to 2002, given estimates of historical acid deposition, and forecast to 2020 based on the reduction in sulphur and nitrogen emissions presupposed by the Gothenburg Protocol. In the 1860s, all lakes were buffered by the carbonate system and only ~6% of lakes had acid neutralising capacity (ANC 50% of the SAA change in sensitive lakes with intermediate weathering rates and little soils (low BC exchangeable capacity and elevated terrestrial export of nitrate and (3 by parallel changes in concentrations of protons and aluminium (each ~20% of the SAA change in extremely sensitive lakes, with the lowest weathering rates and soil base saturation. The full implementation of the Gothenburg Protocol will not be sufficient to allow recovery of the latter group of lakes, which will remain acidified after 2020.

  1. Present and Reference Concentrations and Yields of Suspended Sediment in Streams in the Great Lakes Region and Adjacent Areas

    Science.gov (United States)

    Robertson, Dale M.; Saad, David A.; Heisey, Dennis M.

    2006-01-01

    In-stream suspended sediment and siltation and downstream sedimentation are common problems in surface waters throughout the United States. The most effective way to improve surface waters impaired by sediments is to reduce the contributions from human activities rather than try to reduce loadings from natural sources. Total suspended sediment/solids (TSS) concentration data were obtained from 964 streams in the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River Basins from 1951 to 2002. These data were used to estimate median concentrations, loads, yields, and volumetrically (flow) weighted (VW) concentrations where streamflow data were available. SPAtial Regression-Tree Analysis (SPARTA) was applied to land-use-adjusted (residualized) TSS data and environmental-characteristic data to determine the natural factors that best described the distribution of median and VW TSS concentrations and yields and to delineate zones with similar natural factors affecting TSS, enabling reference or natural concentrations and yields to be estimated. Soil properties (clay and organic-matter content, erodibility, and permeability), basin slope, and land use (percentage of agriculture) were the factors most strongly related to the distribution of median and VW TSS concentrations. TSS yields were most strongly related to amount of precipitation and the resulting runoff, and secondarily to the factors related to high TSS concentrations. Reference median TSS concentrations ranged from 5 to 26 milligrams per liter (mg/L), reference median annual VW TSS concentrations ranged from 10 to 168 mg/L, and reference TSS yields ranged from about 980 to 90,000 kilograms per square kilometer per year. Independent streams (streams with no overlapping drainage areas) with TSS data were ranked by how much their water quality exceeded reference concentrations and yields. Most streams exceeding reference conditions were in the central part of the study area, where agricultural activities

  2. Synergistic effects of UVR and simulated stratification on commensalistic algal-bacterial relationship in two optically contrasting oligotrophic Mediterranean lakes

    Science.gov (United States)

    Carrillo, P.; Medina-Sánchez, J. M.; Durán, C.; Herrera, G.; Villafañe, V. E.; Helbling, E. W.

    2014-08-01

    An indirect effect of global warming is the shallowing epilimnion, causing organisms to be exposed to higher levels of ultraviolet (UVR, 280-400 nm) and photosynthetically active radiation (PAR, 400-700 nm), which could affect primary and bacterial production as well as the commensalistic algal-bacterial relationship. The combined effects of UVR and reduction in the depth of the upper mixed layer (UML) were assessed on variables related to the metabolism of algae and bacteria, during in situ experiments performed with natural microplanktonic communities from two oligotrophic lakes with contrasting UVR-transparency (clear vs. opaque) of southern Spain. The negative UVR effects on epilimnetic primary production (PP) and on heterotrophic bacterial production (HBP), intensified by high mean irradiances, were higher in the UVR-opaque than in the UVR-clear lake, and stronger on the algae than on the heterotrophic bacterial communities. Under UVR and high mean irradiance, the algal-bacterial relationship was strengthened in the UVR-clear lake, where excreted organic carbon (EOC) rates exceeded the bacterial carbon demand (BCD). This did not occur in the UVR-opaque lake. The greater UVR damage to algae and bacteria and the weakening of their commensalistic interaction found in the UVR-opaque lake indicates that these ecosystems would be especially vulnerable to stressors related to global change. Thus, our findings may have important implications for the carbon cycle in oligotrophic lakes of the Mediterranean region.

  3. Delineation of sympatric morphotypes of lake trout in Lake Superior

    Science.gov (United States)

    Moore, Seth A.; Bronte, Charles R.

    2001-01-01

    Three morphotypes of lake trout Salvelinus namaycush are recognized in Lake Superior: lean, siscowet, and humper. Absolute morphotype assignment can be difficult. We used a size-free, whole-body morphometric analysis (truss protocol) to determine whether differences in body shape existed among lake trout morphotypes. Our results showed discrimination where traditional morphometric characters and meristic measurements failed to detect differences. Principal components analysis revealed some separation of all three morphotypes based on head and caudal peduncle shape, but it also indicated considerable overlap in score values. Humper lake trout have smaller caudal peduncle widths to head length and depth characters than do lean or siscowet lake trout. Lean lake trout had larger head measures to caudal widths, whereas siscowet had higher caudal peduncle to head measures. Backward stepwise discriminant function analysis retained two head measures, three midbody measures, and four caudal peduncle measures; correct classification rates when using these variables were 83% for leans, 80% for siscowets, and 83% for humpers, which suggests the measures we used for initial classification were consistent. Although clear ecological reasons for these differences are not readily apparent, patterns in misclassification rates may be consistent with evolutionary hypotheses for lake trout within the Laurentian Great Lakes.

  4. Heavy Metal Enrichment History in annually laminated Lake Tiefer See (NE-Germany) and Lake Czechowskie (N-Poland)

    Science.gov (United States)

    Hoelzmann, Philipp; Dräger, Nadine; Kienel, Ulrike; Ott, Florian; Brauer, Achim

    2015-04-01

    Within the Virtual Institute of Integrated Climate and Landscape Evolution Analyses (ICLEA) high-resolution geo-archives (e.g. lakes as natural data loggers) of the northeastern german and northern polish lowlands are investigated to identify influences of land-use on the landscape evolution. For two annually laminated lake sediment records, situated in rural environments in NE-Germany (Lake Tiefer See) and N-Poland (Czechowskie Lake), we present a detailed heavy metal enrichment history for Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn for the last two hundred years at 1 cm intervals. Both lakes show a similar pattern of relatively low heavy metal concentrations if compared to the so-called index of geoaccumulation (Müller 1979), which is based on the average global metal content in shales (Turekian and Wedepohl, 1961). Only Pb, Zn and Cd show a clear parallel pattern of enrichment in both lakes starting around 1850 according to mainly atmospheric input due to increasing industrialization within the framework of the Industrial Revolution. Highest input for Cd, Zn, and Pb occur around 1960 to 1980 and thereafter a clear pattern of declining anthropogenic input is registered. On the base of heavy-metal analysis of pre-industrial sediments and different sediment types (e.g. calcareous gyttja, organic gyttja etc.) the local and specific geogenic background values for various metals are determined. These results provide means to calculate and quantify with sub-decadal resolution anthropogenic heavy metal accumulations and enrichment factors as well as to define regional measures for a state of reference, reflecting natural conditions without human impact. Müller, G. (1979): Schwermetalle in den Sedimenten des Rheins - Veränderungen seit 1971. Umschau 79: 778-783. Turekian, K. and Wedepohl, K. (1961): Distribution of the elements in some major units of the earth's crust. Bull.Geol.Soc.Am. 72: 175-192.

  5. Optical clearing at cellular level

    Science.gov (United States)

    Kinnunen, Matti; Bykov, Alexander V.; Tuorila, Juho; Haapalainen, Tomi; Karmenyan, Artashes V.; Tuchin, Valery V.

    2014-07-01

    Strong light scattering in tissues and blood reduces the usability of many optical techniques. By reducing scattering, optical clearing enables deeper light penetration and improves resolution in several optical imaging applications. We demonstrate the usage of optical tweezers and elastic light scattering to study optical clearing [one of the major mechanisms-matching of refractive indices (RIs)] at the single particle and cell level. We used polystyrene spheres and human red blood cells (RBCs) as samples and glycerol or glucose water solutions as clearing agents. Optical tweezers kept single microspheres and RBCs in place during the measurement of light scattering patterns. The results show that optical clearing reduces the scattering cross section and increases g. Glucose also decreased light scattering from a RBC. Optical clearing affected the anisotropy factor g of 23.25-μm polystyrene spheres, increasing it by 0.5% for an RI change of 2.2% (20% glycerol) and 0.3% for an RI change of 1.1% (13% glucose).

  6. Roadmap-Based Level Clearing of Buildings

    KAUST Repository

    Rodriguez, Samuel

    2011-01-01

    In this paper we describe a roadmap-based approach for a multi-agent search strategy to clear a building or multi-story environment. This approach utilizes an encoding of the environment in the form of a graph (roadmap) that is used to encode feasible paths through the environment. The roadmap is partitioned into regions, e.g., one per level, and we design region-based search strategies to cover and clear the environment. We can provide certain guarantees within this roadmap-based framework on coverage and the number of agents needed. Our approach can handle complex and realistic environments where many approaches are restricted to simple 2D environments. © 2011 Springer-Verlag.

  7. Study on the Problems of Economic Construction and Ecology Plan in Poyang Lake Region%鄱阳湖环湖区域经济建设与生态规划问题研究

    Institute of Scientific and Technical Information of China (English)

    卢普平; 邱俊; 邹长伟

    2009-01-01

    Poyang lake is the largest fresh water lake in China. Water contamination problem is becoming more and more severely along with the economic development of Jiangxi province. How to exploit and use Poyang lake legitimately to spur the economy in Poyang lake region is becoming a difficult problem that urgently needed to solve. It was minutely discoursed in how to develop the economy of Poyang lake region by strengthening ecological construction. It offered theoretical basis for sustainable development and economic development in the region by analyzing the water recourses, land resources, climate resources, biological resources, mineral resources and tourism resources.%鄱阳湖是中国最大的淡水湖泊,随着江西经济的发展,鄱阳湖的污染问题也变得日益严峻,如何合理开发和利用鄱阳湖带动环湖区域经济发展,为江西经济发展作贡献成为了一个急需解决的难题.文章就加强生态建设,全面推进鄱阳湖环区域经济发展做了详细的论述,从水资源、土地资源、气候资源、生物资源、矿产资源、旅游资源的合理开发进行了综合分析,为鄱阳湖环湖区域经济可持续发展提供了理论依据,对鄱阳湖环湖区域经济开发具有指导意义.

  8. Physical and chemical consequences of artificially deepened thermocline in a small humic lake – a paired whole-lake climate change experiment

    Directory of Open Access Journals (Sweden)

    M. Forsius

    2010-05-01

    Full Text Available Climate change with higher air temperatures and changes in cloud cover, radiation and wind speed alters the heat balance and stratification patterns of lakes. A paired whole-lake thermocline manipulation experiment of a small (0.047 km2 shallow dystrophic lake (Halsjärvi was carried out in southern Finland. A thermodynamic model (MyLake was used for both predicting the impacts of climate change scenarios and for determining the manipulation target of the experiment. The model simulations assuming several climate change scenarios indicated large increases in the whole-lake monthly mean temperature (+1.4–4.4 °C in April–October for the A2 scenario, and shortening of the length of the ice covered period by 56–89 days. The thermocline manipulation resulted in large changes in the thermodynamic properties of the lake, and those were rather well consistent with the simulated future increases in the heat content during the summer-autumn season. The manipulation also resulted in changes in the oxygen stratification, and the expansion of the oxic water layer increased the spatial extent of the sediment surface oxic-anoxic interfaces. The experiment also affected several other chemical constituents; concentrations of TotN, NH4 and organic carbon showed a statistically significant decrease, likely due to both unusual hydrological conditions during the experiment period and increased decomposition and sedimentation. Changes in mercury processes and in the aquatic food web were also introduced. In comparison with the results of a similar whole-lake manipulation experiment in a deep, oligotrophic, clear-watered lake in Norway, it is evident that shallow dystrophic lakes, common in the boreal region, are more sensitive to physical perturbations. This means that projected climate change may strongly modify their physical and chemical conditions in the future.

  9. Great Lakes Environmental Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NOAA-GLERL and its partners conduct innovative research on the dynamic environments and ecosystems of the Great Lakes and coastal regions to provide information for...

  10. Evaluation of the AnnAGNPS Model for Predicting Runoff and Nutrient Export in a Typical Small Watershed in the Hilly Region of Taihu Lake

    Directory of Open Access Journals (Sweden)

    Chuan Luo

    2015-09-01

    Full Text Available The application of hydrological and water quality models is an efficient approach to better understand the processes of environmental deterioration. This study evaluated the ability of the Annualized Agricultural Non-Point Source (AnnAGNPS model to predict runoff, total nitrogen (TN and total phosphorus (TP loading in a typical small watershed of a hilly region near Taihu Lake, China. Runoff was calibrated and validated at both an annual and monthly scale, and parameter sensitivity analysis was performed for TN and TP before the two water quality components were calibrated. The results showed that the model satisfactorily simulated runoff at annual and monthly scales, both during calibration and validation processes. Additionally, results of parameter sensitivity analysis showed that the parameters Fertilizer rate, Fertilizer organic, Canopy cover and Fertilizer inorganic were more sensitive to TN output. In terms of TP, the parameters Residue mass ratio, Fertilizer rate, Fertilizer inorganic and Canopy cover were the most sensitive. Based on these sensitive parameters, calibration was performed. TN loading produced satisfactory results for both the calibration and validation processes, whereas the performance of TP loading was slightly poor. The simulation results showed that AnnAGNPS has the potential to be used as a valuable tool for the planning and management of watersheds.

  11. Dynamics of soil available phosphorus and its impact factors under simulated climate change in typical farmland of Taihu Lake region, China.

    Science.gov (United States)

    Yu, Kaihao; Chen, Xiaomin; Pan, Genxing; Zhang, Xuhui; Chen, Can

    2016-02-01

    Global climate change affects the availability of soil nutrients, thereby influencing crop productivity. This research was conducted to investigate the effects of elevated CO2, elevated temperature, and the interaction of the elevated CO2 and temperature on the soil available phosphorus (P) of a paddy-wheat rotation in the Taihu Lake region, China. Winter wheat (Triticum aestivum L.) was cultivated during the study period from 2011 to 2014 at two CO2 levels (350 μL•L(-1) ambient and 500 μL•L(-1) elevated by 150 μL•L(-1)) and two temperatures (ambient and 2 °C above the ambient). Soil available P content increased at the first season and decreased at the last season during the three wheat growing seasons. Soil available P content showed seasonal variation, whereas dynamic changes were not significant within each growing season. Soil available P content had no obvious trends under different treatments. But for the elevated temperature, CO2, and their combination treatments, soil available P content decreased in a long time period. During the period of wheat ripening stage, significant positive correlations were found between soil available P content and saturated hydraulic conductivity (Ks) and organic matter, but significant negative correlations with soil clay content and pH value; the correlation coefficients were 0.9400 (p climate change scenario.

  12. Is Lake Chabot Eutrophic?

    Science.gov (United States)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  13. Mapping rice cropping systems using Landsat-derived Renormalized Index of Normalized Difference Vegetation Index (RNDVI) in the Poyang Lake Region, China

    Science.gov (United States)

    Li, Peng; Jiang, Luguang; Feng, Zhiming; Sheldon, Sage; Xiao, Xiangming

    2016-06-01

    Mapping rice cropping systems with optical imagery in multiple cropping regions is challenging due to cloud contamination and data availability; development of a phenology-based algorithm with a reduced data demand is essential. In this study, the Landsat-derived Renormalized Index of Normalized Difference Vegetation Index (RNDVI) was proposed based on two temporal windows in which the NDVI values of single and early (or late) rice display inverse changes, and then applied to discriminate rice cropping systems. The Poyang Lake Region (PLR), characterized by a typical cropping system of single cropping rice (SCR, or single rice) and double cropping rice (DCR, including early rice and late rice), was selected as a testing area. The results showed that NDVI data derived from Landsat time-series at eight to sixteen days captures the temporal development of paddy rice. There are two key phenological stages during the overlapping growth period in which the NDVI values of SCR and DCR change inversely, namely the ripening phase of early rice and the growing phase of single rice as well as the ripening stage of single rice and the growing stage of late rice. NDVI derived from scenes in two temporal windows, specifically early August and early October, was used to construct the RNDVI for discriminating rice cropping systems in the polder area of the PLR, China. Comparison with ground truth data indicates high classification accuracy. The RNDVI approach highlights the inverse variations of NDVI values due to the difference of rice growth between two temporal windows. This makes the discrimination of rice cropping systems straightforward as it only needs to distinguish whether the candidate rice type is in the period of growth (RNDVI0).

  14. REGIONAL FUND FOR INDIGENOUS WOMEN IN THE ZIRAHUÉN LAKE REGIÓN OF PÁTZCUARO: CHALLENGES FOR ITS TRANSFORMATION INTO A CREDIT DISPERSOR

    Directory of Open Access Journals (Sweden)

    Laura Elena Garza-Bueno

    2014-07-01

    Full Text Available The conviction that there is a virtuous link between financing and economic growth has resulted in the government promoting financial services. The new financial policies seek to encourage, with particular interest, the inclusion of the population segments that are seldom attended by the commercial and development banks. One of the least attended segments is that found in the rural areas. This is explained by their widely-spaced geographic dispersion, which characterizes the sector. For this reason, verification and follow-up are costly, and agriculture is a high risk activity. To solve this problem, new financial intermediary figures are needed. These figures must operate under schemas that are in accord with local needs. This is the case of the Regional Fund for Indigenous Women of the Zirahuén Lake Region of Pátzcuaro Uarhiti Anchikurhiricha A.C. that currently attends—as a credit dispersor—1774 indigenous women who work basically in handcrafts, avocado production and livestock raising. The experience of this fund is outstanding for its evolution and reach among indigenous women. Given the breadth of the analysis of both aspects, this paper focuses only on the first: the transformation of a subsidy operating Fund into one that administers loans. The complex evolution of the Fund, its technical and financial challenges, in addition to gender problems the women who head the financial organism face, are the object of the study presented here. The results of the study show that managing the change depends on how convinced the leaders of the financial organism are of the importance of the loans as well as on their full comprehension of the demands and possibilities. Above all, however, is their conviction that the women themselves are those that should operate the Fund.

  15. The algal growth-limiting nutrient of lakes located at Mexico’s Mesa Central

    Directory of Open Access Journals (Sweden)

    Fernando W. Bernal-Brooks

    2016-03-01

    Full Text Available This paper reports on the algal growth-limiting nutrients of five lakes located on Mexico’s Mesa Central - a topic poorly known in the regional limnology of Mexico. The five case studies involved three contiguous watersheds of Michoacán State and provided a trophic state variation from mesotrophic to hypereutrophic; the case studies included Lakes Zirahuén, Pátzcuaro, Teremendo, Cuitzeo and the Cointzio Reservoir. The fieldwork involved the collection of physical and chemical data (including nutrients from each case study during the dry and rainy seasons of 2010. Additionally, water samples (1 L were obtained and filtered (0.45 µm in the laboratory to keep the nutrient content available for bioassays. The chemical analyses suggested a phosphorus (P limitation in the Cointzio Reservoir, Lake Teremendo and Lake Zirahuén relative to an N:P>16:1. There was a nitrogen (N limitation at three sampling stations of Lake Pátzcuaro, with an N:P<16:1. As result of the bioassays conducted in July 2012, the Cointzio Reservoir and Lake Teremendo appeared to be P-limited and Lake Pátzcuaro appeared to be N-limited at three sampling stations. Lake Zirahuén showed seasonal variation, with an N limitation during the dry season and a P limitation during the wet season. Those cases with similar results from both methods confirmed the limiting nutrient identification. Lake Cuitzeo, Lake Zirahuén (dry season, and the shallowest sampling station in Lake Pátzcuaro produced unclear results because of divergent outcomes. In terms of the algal growth potential, the Cointzio Reservoir remained unaltered from one season to the next. However, for most of the lakes (with the exception of Lake Pátzcuaro sites 2 and 4, the rainy season provided a dilution effect. Effective lake management depends on a clear recognition of such elements that are in control of the aquatic productivity. In the area of Michoacán, both N and P may act as limiting nutrients.

  16. The art of thinking clearly

    CERN Document Server

    Dobelli, Rolf

    2013-01-01

    The Art of Thinking Clearly by world-class thinker and entrepreneur Rolf Dobelli is an eye-opening look at human psychology and reasoning — essential reading for anyone who wants to avoid “cognitive errors” and make better choices in all aspects of their lives. Have you ever: Invested time in something that, with hindsight, just wasn’t worth it? Or continued doing something you knew was bad for you? These are examples of cognitive biases, simple errors we all make in our day-to-day thinking. But by knowing what they are and how to spot them, we can avoid them and make better decisions. Simple, clear, and always surprising, this indispensable book will change the way you think and transform your decision-making—work, at home, every day. It reveals, in 99 short chapters, the most common errors of judgment, and how to avoid them.

  17. Draft Genome Sequence of Acinetobacter sp. Strain BMW17, a Cellulolytic and Plant Growth-Promoting Bacterium Isolated from the Rhizospheric Region of Phragmites karka of Chilika Lake, India.

    Science.gov (United States)

    Mishra, Samir R; Ray, Lopamudra; Panda, Ananta Narayan; Sahu, Neha; Xess, Sonal S; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar; Raina, Vishakha

    2016-06-30

    We report the 3.16 Mb draft genome of Acinetobacter sp. strain BMW17, a Gram-negative bacterium in the class of Gammaproteobacteria, isolated from the rhizospheric region of Phragmites karka, an invasive weed in Chilika Lake, Odisha, India. The strain BMW17(T) is capable of degrading cellulose and is also an efficient plant growth promoter that can be useful for various phytoremedial and commercial applications.

  18. Writing clear animal activity proposals.

    Science.gov (United States)

    Pinson, David M

    2011-06-01

    Although IACUC-related topics are frequently discussed in the literature, there is little published information about how to write animal activity proposals. In this article, the author discusses key considerations in the writing and review of animal activity proposals. The author then describes a framework for developing and writing clear animal activity proposals that highlight animal welfare concerns. Though these recommendations are aimed at individuals writing and reviewing research proposals, the framework can be modified for other types of animal activity proposals.

  19. Genetically Distinct Glossina fuscipes fuscipes Populations in the Lake Kyoga Region of Uganda and Its Relevance for Human African Trypanosomiasis

    Directory of Open Access Journals (Sweden)

    Richard Echodu

    2013-01-01

    Full Text Available Tsetse flies (Glossina spp. are the sole vectors of Trypanosoma brucei—the agent of human (HAT and animal (AAT trypanosomiasis. Glossina fuscipes fuscipes (Gff is the main vector species in Uganda—the only country where the two forms of HAT disease (rhodesiense and gambiense occur, with gambiense limited to the northwest. Gff populations cluster in three genetically distinct groups in northern, southern, and western Uganda, respectively, with a contact zone present in central Uganda. Understanding the dynamics of this contact zone is epidemiologically important as the merger of the two diseases is a major health concern. We used mitochondrial and microsatellite DNA data from Gff samples in the contact zone to understand its spatial extent and temporal stability. We show that this zone is relatively narrow, extending through central Uganda along major rivers with south to north introgression but displaying no sex-biased dispersal. Lack of obvious vicariant barriers suggests that either environmental conditions or reciprocal competitive exclusion could explain the patterns of genetic differentiation observed. Lack of admixture between northern and southern populations may prevent the sympatry of the two forms of HAT disease, although continued control efforts are needed to prevent the recolonization of tsetse-free regions by neighboring populations.

  20. The ecology of Bartonella spp. infections in two rodent communities in the Mazury Lake District region of Poland.

    Science.gov (United States)

    Welc-Faleciak, Renata; Bajer, Anna; Behnke, Jerzy M; Siński, Edward

    2010-06-01

    Prevalence and abundance of Bartonella spp. infections were studied over a 3-year period in woodland and grassland rodents in North-Eastern Poland. Prevalence of bacterial infections was similar in the two rodent communities, with one leading host species in each habitat (46.3% in Apodemus flavicollis versus 29.1% in Myodes glareolus in forest, or 36.9% in Microtus arvalis versus 13.7% in Mi. oeconomus in grassland). Prevalence/abundance of infections varied markedly across the 3 years with 2006 being the year of highest prevalence and abundance. Infections were more common during autumn months in My. glareolus and A. flavicollis, and in juvenile and young adult (age classes 1 and 2) My. glareolus and Mi. oeconomus than in adults (age class 3). Higher prevalence and abundance of Bartonella infections were found in male A. flavicollis in comparison to females. These data are discussed in relation to the parasite genotypes identified in this region and with respect to the role of various ecological factors influencing Bartonella spp. infections in naturally infected host populations.

  1. Genetically distinct Glossina fuscipes fuscipes populations in the Lake Kyoga region of Uganda and its relevance for human African trypanosomiasis.

    Science.gov (United States)

    Echodu, Richard; Sistrom, Mark; Hyseni, Chaz; Enyaru, John; Okedi, Loyce; Aksoy, Serap; Caccone, Adalgisa

    2013-01-01

    Tsetse flies (Glossina spp.) are the sole vectors of Trypanosoma brucei--the agent of human (HAT) and animal (AAT) trypanosomiasis. Glossina fuscipes fuscipes (Gff) is the main vector species in Uganda--the only country where the two forms of HAT disease (rhodesiense and gambiense) occur, with gambiense limited to the northwest. Gff populations cluster in three genetically distinct groups in northern, southern, and western Uganda, respectively, with a contact zone present in central Uganda. Understanding the dynamics of this contact zone is epidemiologically important as the merger of the two diseases is a major health concern. We used mitochondrial and microsatellite DNA data from Gff samples in the contact zone to understand its spatial extent and temporal stability. We show that this zone is relatively narrow, extending through central Uganda along major rivers with south to north introgression but displaying no sex-biased dispersal. Lack of obvious vicariant barriers suggests that either environmental conditions or reciprocal competitive exclusion could explain the patterns of genetic differentiation observed. Lack of admixture between northern and southern populations may prevent the sympatry of the two forms of HAT disease, although continued control efforts are needed to prevent the recolonization of tsetse-free regions by neighboring populations.

  2. On the Changes of the Hydrological Balance of Caribbean Lakes - Modeling and Observations

    Science.gov (United States)

    Comarazamy, D.; Gonzalez, J.; Glenn, E.; Leon, Y.; Brito, D. R.

    2013-05-01

    . Historical data show precipitation, land surface temperature and humidity, and sea surface temperature (SST), increasing all over the past decades. Salinity levels have also been decreasing by more than 30% from baseline levels. We hypothesized that the increases in SSTs may be leading to increases in regional moisture content which leads to decreases in evaporation capacity from the lakes, and simultaneously to increases in fresh water production in the neighboring sierras. A network of rain and fog gauges along the high sierras reflects growing cloud montane forests, with significant increase in water production. Results from a high-resolution mesoscale atmospheric modeling clearly reflect increases in the amount of liquid water content in the vertical column as function of changing regional climate conditions.

  3. 太湖地区水稻地方品种品质性状多样性研究进展%Research Progresses on Diversity of Quality Traits of Landrace Rice in Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    敖雁; 吴启; 薛萍; 朱志强; 陆豪杰

    2016-01-01

    太湖地区种稻历史悠久,积累了丰富的水稻地方品种资源,水稻地方品种的遗传多样性研究可为优质资源的保护利用以及选育新品种提供一些参考。本文从遗传多样性的概念、研究方法、太湖地区水稻地方品种品质性状多样性研究进展等方面进行了综述,总结了太湖流域水稻地方品种资源的相关利用价值。%It has a long history of rice cultivating in Taihu lake region, with abounds landrace rice resources. The research on genetic di-versity of landrace rice resources can provide some reference for the protection and utilization of high-quality germplasm resources and breeding of new variety. In this study, the author reviewed the concepts of genetic diversity, research methods, genetic diversity of quality traits of landrace rice in Taihu lake region and summarized the relevant utilization value of the landrace rice from Taihu lake region.

  4. Lead isotope ratios in six lake sediment cores from Japan Archipelago: Historical record of trans-boundary pollution sources

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Takahiro, E-mail: hosono@kumamoto-u.ac.jp [Priority Organization for Innovation and Excellence, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Alvarez, Kelly [Priority Organization for Innovation and Excellence, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kuwae, Michinobu [Senior Research Fellow Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2016-07-15

    Sediment cores from six lakes situated from north to south on the Japanese Archipelago were collected during 2009–2010 to investigate the hypothesis that deposition of lead (Pb) was coming from East Asia (including China, South Korea and eastern part of Russia). Accumulation rates and ages of the lake sediment were estimated by the {sup 210}Pb constant rate of supply model and {sup 137}Cs inputs to reconstruct the historical trends of Pb accumulation. Cores from four lakes located in the north and central Japan, showed clear evidence of Pb pollution with a change in the {sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 207}Pb ratios in the recent sediment as compared to the deeper sediment. Among the six studied lakes, significant inputs of anthropogenic lead emissions were observed at Lake Mikazuki (north Hokkaido in north Japan), Lake Chokai (north of Honshu), and Lake Mikuriga (central part of Honshu). Pb isotopic comparison of collected core sediment and previously reported data for wet precipitation and aerosols from different Asian regions indicate that, before 1900, Pb accumulated in these three lakes was not affected by trans-boundary sources. Lake Mikazuki started to receive Pb emissions from Russia in early 1900s, and during the last two decades, this lake has been affected by trans-boundary Pb pollution from northern China. Lake Chokai has received Pb pollutant from northern China since early 1900s until 2009, whereas for the Lake Mikuriga the major Pb contaminant was transported from southern China during the past 100 years. The results of our study demonstrate that Japan Archipelago has received trans-boundary Pb emissions from different parts of East Asian region depending on location, and the major source region has changed historically. - Highlights: • Historical trend of Pb pollution was recorded in six Japanese Lakes. • Pb concentration and Pb isotope ratios were determined for sediment cores. • High [Pb] and less radiogenic Pb isotope ratios

  5. Description and analysis of the poultry trading network in the Lake Alaotra region, Madagascar: implications for the surveillance and control of Newcastle disease.

    Science.gov (United States)

    Rasamoelina-Andriamanivo, H; Duboz, R; Lancelot, R; Maminiaina, O F; Jourdan, M; Rakotondramaro, T M C; Rakotonjanahary, S N; de Almeida, R Servan; Rakotondravao; Durand, B; Chevalier, V

    2014-07-01

    Madagascar's 36.5-million-head poultry industry holds a foremost place in its economy and the livelihood of its people. Unfortunately, regular Newcastle disease outbreaks associated with high mortality causes high losses for smallholders and threatens their livelihood. Therefore, Madagascar is seeking concrete, achievable and sustainable methods for the surveillance and the control of Newcastle disease. In this paper, we present and analyze the results of a field study conducted in Madagascar between December 2009 and December 2010. The study area was the Lac Alaotra region, a landlocked area in the north-eastern part of the country's center. Poultry trading is suspected of playing a major role in the spread of avian diseases, especially in developing countries characterized by many live-bird markets and middlemen. Therefore, the goals of our study were to: (i) describe and analyze smallholders' poultry trading network in the Lake Alaotra region using social network analysis; (ii) assess the role of the network in the spread of Newcastle disease; and (iii) propose the implementation of a targeted disease surveillance based on the characteristics of the poultry trading network. We focused our field study on the harvesting of two data sets. The first is a complete description of the poultry trading network in the landlocked area of Lac Alaotra, including a description of the poultry movements between groups of villages. The second set of data measures the occurrence of outbreaks in the same area by combining a participatory approach with an event-based surveillance method. These data were used to determine the attributes of the network, and to statistically assess the association between the position of nodes and the occurrence of outbreaks. By using social network analysis techniques combined with a classification method and a logistic model, we finally identified 3 nodes (set of villages), of the 387 in the initial network, to focus on for surveillance and control

  6. L-Lake macroinvertebrate community

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  7. Genetic diversity of lake whitefish in lakes Michigan and Huron: sampling, standardization, and research priorities

    Science.gov (United States)

    Stott, Wendylee; VanDeHey, Justin A.; Sloss, Brian L.

    2010-01-01

    We combined data from two laboratories to increase the spatial extent of a genetic data set for lake whitefish Coregonus clupeaformis from lakes Huron and Michigan and saw that genetic diversity was greatest between lakes, but that there was also structuring within lakes. Low diversity among stocks may be a reflection of relatively recent colonization of the Great Lakes, but other factors such as recent population fluctuation and localized stresses such as lamprey predation or heavy exploitation may also have a homogenizing effect. Our data suggested that there is asymmetrical movement of lake whitefish between Lake Huron and Lake Michigan; more genotypes associated with Lake Michigan were observed in Lake Huron. Adding additional collections to the calibrated set will allow further examination of diversity in other Great Lakes, answer questions regarding movement among lakes, and estimate contributions of stocks to commercial yields. As the picture of genetic diversity and population structure of lake whitefish in the Great Lakes region emerges, we need to develop methods to combine data types to help identify important areas for biodiversity and thus conservation. Adding genetic data to existing models will increase the precision of predictions of the impacts of new stresses and changes in existing pressures on an ecologically and commercially important species.

  8. Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa.

    Directory of Open Access Journals (Sweden)

    John Herbert Ainembabazi

    Full Text Available Credible empirical evidence is scanty on the social implications of genetically modified (GM crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA. GM banana has a potential to control the destructive banana Xanthomonas wilt disease.To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease.The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA.We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana.On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production.The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries.

  9. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  10. Novel application of satellite and in-situ measurements to map surface-level NO2 in the Great Lakes region

    Directory of Open Access Journals (Sweden)

    C. Mihele

    2011-11-01

    Full Text Available Ozone Monitoring Instrument (OMI tropospheric NO2 vertical column density data were used in conjunction with in-situ NO2 concentrations collected by permanently installed monitoring stations to infer 24 h surface-level NO2 concentrations at 0.1° (~11 km resolution. The region examined included rural and suburban areas, and the highly industrialised area of Windsor, Ontario, which is situated directly across the US-Canada border from Detroit, MI. Photolytic NO2 monitors were collocated with standard NO2 monitors to provide qualitative data regarding NOz interference during the campaign. The accuracy of the OMI-inferred concentrations was tested using two-week integrative NO2 measurements collected with passive monitors at 18 locations, approximating a 15 km grid across the region, for 7 consecutive two-week periods. When compared with these passive results, satellite-inferred concentrations showed an 18% positive bias. The correlation of the passive monitor and OMI-inferred concentrations (R=0.69, n=115 was stronger than that for the passive monitor concentrations and OMI column densities (R=0.52, indicating that using a sparse network of monitoring sites to estimate concentrations improves the direct utility of the OMI observations. OMI-inferred concentrations were then calculated for four years to show an overall declining trend in surface NO2 concentrations in the region. Additionally, by separating OMI-inferred surface concentrations by wind direction, clear patterns in emissions and affected down-wind regions, in particular around the US-Canada border, were revealed.

  11. Estimating the volume of Alpine glacial lakes

    Science.gov (United States)

    Cook, S. J.; Quincey, D. J.

    2015-12-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38) and that although lake volume and area are well correlated (r2 = 0.91), and indeed are auto-correlated, there are distinct outliers in the data set. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled data set to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  12. [Ecotourism exploitation model in Bita Lake Natural Reserve of Yunnan].

    Science.gov (United States)

    Yang, G; Wang, Y; Zhong, L

    2000-12-01

    Bita lake provincial natural reserve is located in Shangri-La region of North-western Yunnan, and was set as a demonstrating area for ecotourism exploitation in 1998. After a year's exploitation construction and half a year's operation as a branch of the 99' Kunming International Horticulture Exposition to accept tourists, it was proved that the ecotourism demonstrating area attained four integrated functions of ecotourism, i.e., tourism, protection, poverty clearing and environment education. Five exploitation and management models including function zoned exploitation model, featured tourism communication model signs system designing model, local Tibetan family reception model and environmental monitoring model, were also successful, which were demonstrated and spreaded to the whole province. Bita lake provincial natural reserve could be a good sample for the ecotourism exploitation natural reserves of the whole country.

  13. Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city region, China

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Haruhiko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)]. E-mail: nakata@sci.kumamoto-u.ac.jp; Hirakawa, Yuko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kawazoe, Masahiro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, (Japan); Nakabo, Tetsuji [Kyoto University Museum, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Arizono, Koji [Faculty of Environmental and Symbiotic Sciences, Kumamoto Prefectural University, 3-1-100 Tsukide, Kumamoto 862-8502 (Japan); Abe, Shin-Ichi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kitano, Takeshi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Hideaki [Faculty of Education, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Watanabe, Izumi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchuu-city, Tokyo 183-8509 (Japan); Li Weihua [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China); Ding Xucheng [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China)

    2005-02-01

    Contamination by persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) were examined in sediments, soils, fishes, crustaceans, birds, and aquaculture feed from Lake Tai, Hangzhou Bay, and in the vicinity of Shanghai city in China during 2000 and 2001. OCs were detected in all samples analyzed, and DDT and its metabolites were the predominant contaminants in most sediments, soils and biota. Concentrations of p,p'-DDT and ratio of p,p'-DDT to {sigma}DDTs were significantly higher in marine fishes than those in freshwater fishes. While the use of DDTs has been officially banned in China since 1983, these results indicate a recent input of technical DDTs into the marine environment around Hangzhou Bay. Comparison of organochlorine concentrations in fishes collected from Lake Tai and Hangzhou Bay suggests the presence of local sources of HCHs, chlordanes and PCBs at Lake Tai. Higher proportions of penta- and hexa-PCB congeners in fishes at Lake Tai may suggest the use of highly chlorinated PCB product, such as PCB{sub 5}, around this lake. To our knowledge, this is a first comprehensive study to examine the present status of organochlorine contamination in various environmental media, such as sediments, soils and wildlife, in China. - Elevated concentrations of DDTs were detected in sediments, soils, and wildlife collected from China.

  14. LAKE VICTORIA AND THE COMMON PROPERTY DEBATE: IS THE TRAGEDY OF THE COMMONS A THREAT TO ITS FUTURE?

    Directory of Open Access Journals (Sweden)

    Erick Ochieng OGELLO

    2013-12-01

    Full Text Available Lake Victoria is the largest among the African Great Lakes in East African region that are believed to have both dynamic and fragile aquatic ecosystems. Within two decades, the lake has experienced extensive resource exploitation leading to constrained productivity and drastic decline of native biodiversity. Intensive non-selective fishing, catchment vegetation degradation, industrial and agricultural pollution, the introduction of exotic species and uneven patchwork of governmental laws are some of the reasons for the current ecological woes facing Lake Victoria. This paper intends to stimulate recognition of Lake Victoria and its catchment as a lived Com­mons, to be shared, protected, managed and enjoyed by all who live around it. The paper compares the original biodiversity status of the lake with the current status and discusses the role of unlimited access as a function of the loss of the Lake’s biological wealth. The Lake’s water resource base, fishery, wetlands and other aquatic resources have been exhaustively discussed. In this review, we uphold the Hardin’s school of thought that freedom of the commoners causes resource overuse leading to poverty. Therefore, limiting freedom could be essential. However, there is need for provision of alternative means of survival since people with no choices would continue over-exploiting ecosystems even under limited access. The Lake Victoria basin commons should be protected by strict legal and clear political frame­work based on public trust doctrine, reinforced in law that the Lake is vital for the survival of people, plants and animals living on or near it and therefore must be protected for the common good. The political jurisdictions should consider governing the Lake basin as one integrated watershed. It is our fervent hope that bordering communities will secure grass root movements to protect and nurture Lake Victoria and its environs for the benefit of the present and future

  15. Influence of climate changes on the blooms and toxin production of cyanobacteria in the lakes of Latvia (north-eastern Baltic Sea region)

    Science.gov (United States)

    Briede, Linda; Barda, Ieva; Purina, Ingrida

    2016-04-01

    Global climate changes have influenced lakes ecosystems resulting in prolonged vegetation season. Long term data shows the earlier warming of water in spring and later cooling in autumn. These modifications are promoting the changes of phytoplankton community from diatom and chrysophytes dominated communities towards cyanobacteria dominated communities. Cyanobacteria are well known as procariotic ancient organisms involved in the production of oxygen, however nowadays they are better known as producers of potent toxins. Long term dynamic of cyanobacterial communities were investigated in lakes Burtnieku and Aluksnes (northern Latvia). Most common cyanobacterial genus were Aphanizomenon, Anabaena, Microcystis, Planktothrix as well as Gloeotrichia known to produce hepatotoxins and neurotoxins. Seasonal toxin production of cyanobacteria was screened using ELISA kits in year 2015. Implications of prolonged cyanobacterial blooms and toxin production on lakes ecosystem are discussed.

  16. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    reproduction of zooplanktivorous European whitefish, Coregonus lavaretus, which feeds highly selectively on large cladocerans and which is of great economic significance for the whole region. Another possibility could be that the lack of large Cladocera in the Lower Lake is a result of strong fish predation which could be a consequence of lake morphology.

  17. Holocene lake deposits of Bosten Lake, southern Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    B. Wünnemann; CHEN Fahu; F. Riedel; ZHANG Chengjun; S. Mischke; CHEN Guangjie; D. Demske; MING Jin

    2003-01-01

    A 9.25-m-long sediment core from Bosten Lake, Xinjiang, provides detailed information about changes in the water budget and biological acticity over the last 8400 calendar years. The chronology is constructed from six AMS radiocarbon dates on the terrestrial plant remains. Based on analyses of TOC, CO3, detrital compounds and biogenic SiO2, lake level fluctuations and periods of remarkably-negative water budget appeared at 8.4-8.2 cal ka, 7.38-7.25 cal ka, 5.7-5.5 cal ka, 3.7-3.4 cal ka and 3.3-2.9 cal ka, respectively. As they are in-phase with low lake levels at Sumxi Co and Bangong Co in western Tibet Plateau and with paleolakes in Inner Mongolia, a climate-induced change to somewhat drier andwarmer conditions is inferred. A further drop in lake level after 1320 AD of about 200 yr duration may be attributed to a negative water balance prior to the main phase of the Little Ice Age. Deep and stable lake phases of 1500 yr and 1800yr duration at 7.2-5.7 cal ka and 5.5-3.7 cal ka coincide with maximum moisture during the Holocene Megathermal in China. The long term trend towards ariditysince about 4.3 cal ka can clearly be recognised. The reduced water budget of Bosten Lake from 640-1200 AD may be attributed to local effects.

  18. [Content of natural uranium in the lichens and distribution of forms in the soil at the coastal area of Lakes Itkul and Sinara of Chelyabinsk region].

    Science.gov (United States)

    Polyudina, A L; Deryagin, V V; Levina, S G

    2014-01-01

    The distribution of natural uranium in soils superaquatic and transeluvial positions of the coastal landscape of lakes Itkul and Sinara, and liches on this site.The necessity of analysis of the content item in accordance with its form of occurrence in the natural environment. The peculiarities of the migration, accumulation and distribution of uranium in soils of the mountain areas of the watersheds of lakes Itkul and Sinara are found. Identified of specificity species lichens on the content of uranium in the substrate.

  19. Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer

    Science.gov (United States)

    Glaz, P.; Gagné, J.-P.; Archambault, P.; Sirois, P.; Nozais, C.

    2015-12-01

    Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L-1 compared to 12.5 mgC L-1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.

  20. Glacial lakes in the Indian Himalayas--from an area-wide glacial lake inventory to on-site and modeling based risk assessment of critical glacial lakes.

    Science.gov (United States)

    Worni, Raphael; Huggel, Christian; Stoffel, Markus

    2013-12-01

    Glacial lake hazards and glacial lake distributions are investigated in many glaciated regions of the world, but comparably little attention has been given to these topics in the Indian Himalayas. In this study we present a first area-wide glacial lake inventory, including a qualitative classification at 251 glacial lakes >0.01 km(2). Lakes were detected in the five states spanning the Indian Himalayas, and lake distribution pattern and lake characteristics were found to differ significantly between regions. Three glacial lakes, from different geographic and climatic regions within the Indian Himalayas were then selected for a detailed risk assessment. Lake outburst probability, potential outburst magnitudes and associated damage were evaluated on the basis of high-resolution satellite imagery, field assessments and through the use of a dynamic model. The glacial lakes analyzed in the states of Jammu and Kashmir and Himachal Pradesh were found to present moderate risks to downstream villages, whereas the lake in Sikkim severely threatens downstream locations. At the study site in Sikkim, a dam breach could trigger drainage of ca. 16×10(6)m(3) water and generate maximum lake discharge of nearly 7000 m(3) s(-). The identification of critical glacial lakes in the Indian Himalayas and the detailed risk assessments at three specific sites allow prioritizing further investigations and help in the definition of risk reduction actions.

  1. Hydrology of Hunters Lake, Hernando County, Florida

    Science.gov (United States)

    Henderson, S.E.

    1986-01-01

    The size and shape of Hunters Lake, Florida has been significantly altered by development of the surrounding Spring Hill residential community. The lake is the largest in Hernando County, enlarged by lakeshore excavation and connection to nearby ponds to an area of 360 acres at an average stage of 17.2 ft above sea level. Hunters Lake is naturally a closed lake, but development of Spring Hill has resulted in a surface water outflow from the lake in its southwest corner. Inflow to the lake could occur on the east side during extreme high-water periods. The karst terrain of the Hunters Lake area is internally drained through permeable soils, depressions, and sinkholes, and natural surface drainage is absent. The underlying Floridan aquifer system is unconfined except locally near coastal springs. Flow in the groundwater system is to the west regionally and to the southwest in the immediate area of Hunters Lake. Water level gradients in the groundwater system increase from 1.4 ft/mi east of the lake to about 8 ft/mi southwest of the lake. Hunters Lake is hydraulically connected to the groundwater system, receiving groundwater on the northeast side and losing water to the groundwater system on the southwest side. This close relationship with the groundwater system is demonstrated by graphical and numerical comparison of Hunters Lake stage with water levels in nearby groundwater sites. During 1965-84, the stage of Hunters Lake fluctuated between 12.48 and 20.7 ft above sea level. Because area lakes are all directly affected by groundwater levels, they also show a close relationship with water levels in Hunters Lake. Analysis of water quality data for Hunters Lake indicates that the water of the lake is a soft calcium bicarbonate type with ionic concentrations higher than in water from nearby shallow wells and lower than in water from the Upper Floridan aquifer. Samples collected in 1981-1983 indicate slightly higher levels of ionic concentration than in 1965

  2. Role of socio-cultural and economic factors in cyprinid fish distribution networks and consumption in Lawa Lake region, Northeast Thailand: Novel perspectives on Opisthorchis viverrini transmission dynamics.

    Science.gov (United States)

    Kim, Christina Sunyoung; Smith, John F; Suwannatrai, Apiporn; Echaubard, Pierre; Wilcox, Bruce; Kaewkes, Sasithorn; Sithithaworn, Paiboon; Sripa, Banchob

    2017-02-16

    Opisthorchis viverrini (Ov) is a fish-borne parasite endemic in parts of Lao PDR, Cambodia, southern Vietnam and Northeast Thailand (Isaan) where an estimated 10 million people are infected. Human Ov infection, associated with hepatobiliary complications, including cholangiocarcinoma (CCA), occurs when infected fish are consumed raw or undercooked, a longstanding cultural tradition in the region. This mixed- methods descriptive study was carried out in Isaan villages around Lawa Lake, Khon Kaen Province, known for their Ov endemicity. Focus group discussions (FGDs) and in depth interviews (IDIs) were used to explore socio-cultural determinants underlying raw fish consumption practices, and global positioning system (GPS) devices to map local fish distribution networks. Qualitative data affirmed major socio-cultural and dietary lifestyle transitions occurring consequent on recent decades of modernization policies and practices, but also the persistence of Isaan traditional raw-fish eating practices and incorrect beliefs about infection risk avoidance. Fish traders/middlemen purchase most of the catch at the lakeshore and play the dominant role in district market fish distribution networks, at least for the larger and less likely infected, fish species. The lower economic value of the small potentially-infected cyprinid fish means local fishermen typically distribute them free, or sell cheaply, to family and friends, effectively concentrating infection risk in already highly Ov infected villages. Our study confirmed the persistence of traditional Isaan raw-fish meal practices, despite major ongoing socio-cultural lifestyle transitions and decades of Ov infection health education programs. We contend that diffuse socio-cultural drivers underpin this practice, including its role as a valued cultural identity marker. A "fish economics" factor was also evident in the concentration of more likely infected fish back into local villages due to their low economic value at

  3. Long-Term Effects of Inorganic and Organic Amendments on Organic Carbon in a Paddy Soil of the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    MA Li; YANG Lin-Zhang; XIA Li-Zhong; SHEN Ming-Xing; YIN Shi-Xue; LI Yun-Dong

    2011-01-01

    A long-term experiment set up in 1980 compared the effects of applying manures and chemical fertilizers on a paddy soil in the Taihu Lake region, China. Of the fourteen randomly distributed treatments consisting of different combinations of organic manure, inorganic nitrogen (N), phosphorus (P), and potassium (K), and rice straw, eight were selected for the present study in 2007. Application of organic manure plus straw significantly increased soil organic carbon (SOC) content of the topsoil (0-10 cm) compared to that of chemical fertilizers alone. The content of SOC was relatively stable in the 10-30 cm layer in the chemical fertilizer treatments and in the 20-40 cm layer in the manure treatments. The stable carbon isotope ratio (δ13C) ranged from -24‰ to -28‰ and increased gradually with depth. The content of SOC was significantly (P < 0.05) negatively correlated with δ13C. In the 0-20 cm layer, the δ13C value significantly decreased in the treatments of manure alone (M), manure and chemical N and P fertilizers (MNP), manure and chemical N, P, and K fertilizers (MNPK), manure, rice straw, and chemical N fertilizer (MRN), and chemical N fertilizer and rice straw (CNR), as compared with the no-fertilizer control. In the 30-50 cm layer, however, the ratio significantly increased in all the treatments except Treatment CNR. Mineralization of organic C peaked in the first 2-4 d of incubation and gradually leveled off thereafter over the first 3 weeks, being faster in the manure treatments than the chemical fertilizer treatments. The average rate of mineralization varied from 55.36 to 75.46 mL CO2 kg-1 d-1 and that of stable mineralization from 10 to 20 mL CO2 kg-1 d-1. In eight weeks of incubation, cumulative mineralization was always higher in the manure treatments than the chemical fertilizer treatments, being the highest in Treatment MRN. Combined humus in the soil was mainly (over 50%) composed of tightly combined fraction. The loosely combined humus and

  4. Discovery of a Plains Caldera Complex and Extinct Lava Lake in Arabia Terra, Mars: Implications for the Discovery of Additional Highland Volcanic Source Regions

    Science.gov (United States)

    Bleacher, Jacob; Michalski, Joseph

    2012-01-01

    Several irregularly shaped topographic depressions occur near the dichotomy boundary in northern Arabia Terra, Mars. The geomorphology of these features suggests that they formed by collapse, opposed to meteor impact. At least one depression (approx.55 by 85 km) displays geologic features indicating a complex, multi-stage collapse history. Features within and around the collapse structure indicate volcanic processes. The complex occurs within Hesperian ridged plains of likely volcanic origin and displays no crater rim or evidence for ejecta. Instead the depression consists of a series of circumferential graben and down-dropped blocks which also display upper surfaces similar to ridged plain lavas. Large blocks within the depression are tilted towards the crater center, and display graben that appear to have originally been linked with circumferential graben outside of the complex related to earlier collapse events. A nearly 700 m high mound exists along a graben within the complex that might be a vent. The deepest depression displays two sets of nearly continuous terraces, which we interpret as high-stands of a drained lava lake. These features appear similar to the black ledge described during the Kilauea Iki eruption in 1959. A lacustrine origin for the terraces seems unlikely because of the paucity of channels found in or around the depression that could be linked to aqueous surface processes. In addition, there is no obvious evidence for lacustrine sediments within the basin. Together with the presence of significant faulting that is indicative of collapse we conclude that this crater complex represents a large caldera formed in the Late Noachian to Early Hesperian. Other linear and irregular depressions in the region also might be linked to ancient volcanism. If that hypothesis is correct, it suggests that northern Arabia Terra could contain a large, previously unrecognized highland igneous province. Evacuation of magma via explosive and effusive activity

  5. The tempo of Holocene climatic change in the eastern Mediterranean region : new high-resolution crater-lake sediment data from central Turkey

    NARCIS (Netherlands)

    Reed, JM; Leng, MJ; Kuzucuoglu, C; Fontugne, M; Bertaux, J; Bottema, S; Black, S; Hunt, E; Karabiyikoglu, M; Woldring, H.

    2001-01-01

    This study presents results from a multi-proxy analysis of cores taken in a crater-lake sequence from Eski Acigol in central Turkey which cover the period from pre-c. 16000 cal. yr BP to the present. The sediments comprise an upper unit of generally non-laminated, banded to massive silts and peats o

  6. Why did the Nepal Gorkha Earthquake Have so few Effects on Glacial Lakes?

    Science.gov (United States)

    Kargel, J. S.; Collins, B. D.; Fielding, E. J.; Fujita, K.; Haritashya, U. K.; Hudnut, K. W.; Leonard, G. J.; Shugar, D. H.; Sakai, A.; Jibson, R.

    2015-12-01

    On 25 April 2015, a magnitude 7.8 earthquake struck Nepal. Subsequently many large aftershocks shook the region, including one of magnitude 7.3. Much damage occurred and over 4000 landslides were triggered, but fortunately few earthquake effects on glacier lakes have been identified and no large glacier lake outburst floods (GLOFs) have been clearly attributed to the quakes. Why were the lakes largely unscathed? We will (1) review some cases around the world where earthquakes have apparently triggered responses among glaciers and glacier- or moraine-dammed lakes, and how these responses took place, (2) consider why earthquakes in general might not commonly have such large impacts on glacial lakes as widely expected; (3) show some case examples of glacial moraine-dammed lakes in Nepal and Tibet where few visible effects of the Gorkha earthquake (and aftershocks) were documented; and (4) consider why specifically the Gorkha earthquake (+ aftershocks) caused very few and mild effects. Earthquake shaking and steep slopes result in thousands of landslides when big earthquakes occur in mountains; furthermore, large mass movements into glacial lakes are a known trigger of many GLOFs. Worldwide there is little evidence, contrary to speculation, and now reinforced by the Gorkha quake, that earthquakes—even big ones happening near glacier lakes—are normally a major trigger of GLOFs. There may be several explanations. The Gorkha earthquake might have caused less shaking than its total released energy suggests, thus further sparing the Himalayan lakes from catastrophe. A possible further protective aspect is that glacial lakes mainly occur far up alpine valleys. It is known from other quakes that when there is shallow slip and rugged relief, surface wave modes tend to be absorbed and scattered as these waves propagate across mountain ranges, and body waves are focused into ridges, thus reducing the ground accelerations on valley floors (where lakes occur) and commonly

  7. Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco from five lakes in the middle and lower reaches of the Yangtze River, China, based on mitochondrial DNA control region.

    Science.gov (United States)

    Zhong, Liqiang; Song, Chao; Wang, Minghua; Chen, Youming; Qin, Qin; Pan, Jianlin; Chen, Xiaohui

    2013-10-01

    Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco were examined by using mitochondrial DNA control region sequences in 143 specimens sampled from five lakes in the middle and lower reaches of the Yangtze River, China; 151 polymorphic sites defined 72 distinct haplotypes. Haplotype diversity indices (0.903-0.953) and nucleotide diversity indices (0.00378-0.00970) demonstrated low genetic diversity of the yellow catfish populations in the five lakes. The analysis of molecular variance and the fixation index (F(st) = 0.0896) revealed insignificant genetic difference between samples from different lakes. In addition, neutral tests and analysis of mismatch distribution suggested that yellow catfish might have undergone a population expansion. Neighbor-joining tree indicated a correlation between these population genetic differences and geographic distance. This study revealed the extant population genetic diversity and structure of the yellow catfish and was in favor of the related fishery management issues including fishery stock identification, conservation, and artificial breeding.

  8. Lake trout demographics in relation to burbot and coregonine populations in the Algonquin Highlands, Ontario

    Science.gov (United States)

    Carl, L.M.

    2008-01-01

    The objective of the study was to test the hypothesis that lake trout populations change in relation to cisco, lake whitefish, round whitefish and burbot populations in lakes in the Algonquin Highlands region of Ontario. Lake trout population change is greatest where cisco and lake whitefish are present. Lake trout populations in lakes without either coregonine tend to have small adults and many juveniles. Where cisco or lake whitefish are present, adult lake trout are large, juvenile abundance is low, and the stock-recruit relationship appears to be uncoupled likely due to a larval bottleneck. Lake trout populations in these lakes may be sensitive to overfishing and recruitment failure. Lake trout populations do not appear to change in relation to round whitefish. There appears to be an indirect positive change on juvenile lake trout abundance through reductions in the density of benthic coregonines in the presence of large, hypolimnetic burbot. ?? 2007 Springer Science+Business Media B.V.

  9. Morphological variation of siscowet lake trout in Lake Superior

    Science.gov (United States)

    Bronte, C.R.; Moore, S.A.

    2007-01-01

    Historically, Lake Superior has contained many morphologically distinct forms of the lake trout Salvelinus namaycush that have occupied specific depths and locations and spawned at specific times of the year. Today, as was probably the case historically, the siscowet morphotype is the most abundant. Recent interest in harvesting siscowets to extract oil containing omega-3 fatty acids will require additional knowledge of the biology and stock structure of these lightly exploited populations. The objective of this study was to determine whether shape differences exist among siscowet populations across Lake Superior and whether these shape differences can be used to infer stock structure. Morphometric analysis (truss protocol) was used to differentiate among siscowets sampled from 23 locations in Lake Superior. We analyzed 31 distance measurements among 14 anatomical landmarks taken from digital images of fish recorded in the field. Cluster analysis of size-corrected data separated fish into three geographic groups: The Isle Royale, eastern (Michigan), and western regions (Michigan). Finer scales of stock structure were also suggested. Discriminant function analysis demonstrated that head measurements contributed to most of the observed variation. Cross-validation classification rates indicated that 67–71% of individual fish were correctly classified to their region of capture. This is the first study to present shape differences associated with location within a lake trout morphotype in Lake Superior.

  10. Piscivory and trophic position of Anguilla anguilla in two lakes: importance of macrozoobenthos density

    DEFF Research Database (Denmark)

    Dorner, H.; Skov, Christian; Berg, Søren;

    2009-01-01

    The feeding habits of the European eel Anguilla anguilla (> 300 mm total length, L-T) were compared in two lakes of different environmental state: Lake Gro ss er Vatersee (LGV), Germany (clear water, mesotrophic and submerged macrophytes), and Lake Vallum (LV), Denmark (turbid, eutrophic and no s......The feeding habits of the European eel Anguilla anguilla (> 300 mm total length, L-T) were compared in two lakes of different environmental state: Lake Gro ss er Vatersee (LGV), Germany (clear water, mesotrophic and submerged macrophytes), and Lake Vallum (LV), Denmark (turbid, eutrophic...

  11. A progress report on results of test drilling and ground-water investigations of the Snake Plain aquifer, southeastern Idaho: Part 1: Mud Lake Region, 1969-70 and Part 2: Observation Wells South of Arco and West of Aberdeen

    Science.gov (United States)

    Crosthwaite, E.G.

    1973-01-01

    The results of drilling test holes to depths of approximately 1,000 feet in the Mud Lake region show that a large part of the region is underlain by both sedimentary deposits and basalt flows. At some locations, predominantly sedimentary deposits were penetrated; at others, basalt flows predominated. The so-called Mud Lake-Market Lake barrier denotes a change in geology. From the vicinity of the barrier area, as described by Stearns, Crandall, and Steward (1938, p. 111), up the water-table gradient for at least a few tens of miles, the saturated geologic section consists predominantly of beds of sediments that are intercalated with numerous basalt flows. Downgradient from the barrier, sedimentary deposits are not common and practically all the water-bearing formations are basalt, at least to the depths explored so far. Thus, the barrier is a transition zone from a sedimentary-basaltic sequence to a basaltic sequence. The sedimentary-basaltic sequence forms a complex hydrologic system in which water occurs under water-table conditions in the upper few tens of feet of saturated material and under artesian conditions in the deeper material in the southwest part of the region. The well data indicate that southwest of the barrier, artesian pressures are not significant. Southwest of the barrier, few sedimentary deposits occur in the basalt section and, as described by Mundorff, Crosthwaite, and Kilburn (1964). ground water occurs in a manner typical of the Snake Plain aquifer. In several wells, artesian pressures are higher in the deeper formations than in the shallower ones, but the reverse was found in a few wells. The available data are not adequate to describe the water-bearing characteristics of the artesian aquifer nor the effects that pumping in one zone would have on adjacent zones. The water-table aquifer yields large quantities of water to irrigation wells.

  12. Physical and Chemical Characteristics of Lake Edku Water, Egypt

    Directory of Open Access Journals (Sweden)

    M.A. OKBAH

    2012-12-01

    Full Text Available The objective of this work is to evaluate the quality of Lake Edku water. Regional and seasonal variations of some physico-chemical parameters (nutrient salts, total nitrogen, total phosphorous and silicate, in addition to pH, total alkalinity, chlorosity, dissolved oxygen, biological oxygen demand and oxidizable organic matter that were determined during the period from January to December 2000. Important variations have occurred in the investigated area as a result of human activity and the discharge of wastewater to the lake. The relatively low pH values reflect the decreased productivity of the Lake as a result of the polluted water discharged into the lake. Total alkalinity varied between 2.25 ± 0.35 to 8.38 ± 0.9 meq/l. In comparison with previous decades chlorosity content (586-1562 mg/l showed the general decreasing trend. Dissolved oxygen varied (2.37 ± 0.72 - 4.47 ± 0.94 mg/l. The ratios of BOD/ OOM values indicate that the lake water has a biodegradable nature. There was a noticeable variation in ammonia levels; a lower ammonia content was recorded in summer and spring. Nitrite and nitrate concentrations in Lake Edku water showed values ranging from 3.7±1.4 to 7.8±1.9 ΜM and from 15.2±2.9 to 45.9±11.8 ΜM, respectively. The total nitrogen of the lake exhibited higher levels (53.1±12.2 – 164.2±30.7 ΜM. The ratio of NH4/TIN (0.09-0.45 seems to be highly representative of the microbial nitrification rate as well as of the varying agricultural inflows. It is interesting to note that increasing values of reactive phosphate (11.6±1.8 – 14.7±2.5 ΜM were determined in autumn and winter respectively. The higher concentrations of reactive silicate were directly proportional to drainage water discharged into the Lake. It is clear from the mean ratio of N/P (2.4-8.8 nitrogen is the limiting factor. The lower values of N/P ratio could be related to an allochthonous condition.

  13. Recent fault movement in Lake McDonald, Montana: Evidence from acoustic sub-bottom profiling

    Science.gov (United States)

    Dunbar, J. A.; Cronin, V. S.; Allen, P. M.; White, J. D.

    2011-12-01

    Lake McDonald is the largest of the 12 large lakes in Glacier National Park, Montana, formed in previously glaciated valleys and dammed by outwash and moraine deposits at their outlets. Lake McDonald is 15 km long, 1.6 km wide and trends northeast. The location of the lake was on the eastern edge of the Cordilleran Ice Sheet during the late Wisconsin Glaciation. Published maps indicate the lake basin is crossed by the northwest-striking Flathead and Nyack normal faults and two unnamed faults (Whipple, 1992, USGS Map I-1508-F). Recent seismicity in northwest Montana consists mostly of magnitude 3 to 4 earthquakes, one of which occurred between the Flathead and Nyack faults, northwest of the lake. Using 1 kHz Uniboom profiling of Lake McDonald, Mullins and others (1991, Arctic Alpine Res 23(3), 311-319) found 150 m of simply-stratified, undisturbed sediment fill within a V-shaped bedrock basin with steeply sloping sides. No evidence was found to suggest that the faults within the lake have been recently active. In this study, we collected 55 km of 24 kHz sub-bottom profiling data to more closely examine the upper 10 m of the sediment fill for evidence of recent fault motion. The upper 10 m of the fill consists of sub-meter thick, alternating layers of highly reflective and nearly acoustically transparent deposits, along with numerous chaotic mass-wasting deposits emanating from the adjacent sides of the basin. One of these mass-wasting deposits is 1.3 km wide, 5 m thick, and lies unburied on the modern lake floor. The trace of Flathead Fault, where it crosses the northeastern end of the lake, is marked by a precipitous, 125 m high, down-to-the-southwest escarpment. The base of the escarpment consists of a series of basinward-stepping terraces, the southwestern-most of which is onlapped by recent sediment. The onlapping sediments show no clear evidence of faulting next to the escarpment, but motion between the various terraces cannot be ruled out. The trace of Nyack

  14. Sediment Particle Sizes and the Dry- Humid Transformation of the Regional Climate in Erhai Lake%洱海沉积物粒度记录与气候干湿变迁

    Institute of Scientific and Technical Information of China (English)

    陈敬安; 万国江; 徐经意

    2000-01-01

    通过对洱海现代沉积物的精细采样,将放射性核素精确计年与沉积物粒度研究相结合,重建了600多年来洱海区域气候的干湿变迁,为恢复百年尺度的气候干湿变化提供了一条新途径。研究结果表明,15世纪是洱海地区最为湿润的一个世纪;洱海区域存在100a、200a两种时间尺度的气候干湿准周期波动;自19世纪末以来洱海区域气候整体上向干旱化方向发展,目前正处于干旱期末期,预计气候将由干旱转向湿润。%As a main lodging of surface substances, lake sediments continuously and sensitively record information of re-gional climate and environment with annual to decadal resolution. The sediment core EH911208 - 3 - 5 with alength of 83cm was taken from deepwater location in Erhai Lake in 1991, using the sediment - water interface sampler specially designed by ourselves. The sediments were cut at intervals of 0.5~1.0cm and were measured forgrain sizes by the Scanning Photo Sedimentograph "Analysette 20" made in Germany. Based on accurate dating by137Cs and 210Pbex, the author reconstructs the dry - humid transformation history of the regional climate accordingto the vertical profile of sediment particle sizes, which provides a new effective way for recovering the century-scale climatic changes. The following conclusions are drawn: (1) General environmental significance of sediment grain size should not be applied mechanically in recon-structing palaeoclimate. Only after concretely analyzing all the factors which affect sediment grain size, can credi-ble conclusions be obtained during discussing different time - scales climate changes. (2) During long time- scale studies, lake level is the most important factor dominating sediment grain size.Sediments are finer during the humid period of high water level because coarse particles can not be transported tothe lake's deepwater part. On the contrary, during short time- scale studies within a

  15. Modern pollen rain in the Lake Qinghai basin, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Lake Qinghai is the largest inland brackish lake in China and lies within the NE Tibetan Plateau. Our study shows that pollen assemblages in each vegetation belt are significantly correlated with the vegetation types of this area. Among the herbaceous and shrubby pollen assemblages, Artemisia is over-represented, while Poaceae, Cyperaceae and Polygonaceae are under-represented. Artemisia/ Chenopodiaceae (A/C) ratios with the regional vegetation characteristic can be used as a proper index to reconstruct the history of vegetation and climate in Lake Qinghai basin. Modern pollen in the lake mainly comes from the nearby vegetation, controlled by the directions and velocity of the wind. The distribution of modern pollen in Lake Qinghai tends to be similar in most part of the lake. The difference of pollen sedimentation process in the lake can be potentially influenced by the focusing function of the lake, river streams, and lake current.

  16. Catalog of crater lakes from Costa Rica

    Science.gov (United States)

    Ramirez, C. J.; Mora-Amador, R.; González, G.

    2010-12-01

    Costa Rica has a diversity of volcanic crater lakes that can be classified into two groups: hot and cold lakes. The country contains at least 5% of the world's hot lakes. Costa Rica has 2 hot hyperacidic lakes, both of them on active volcanoes, the Rincón de la Vieja (38.0°C, pH = 0 - 1) and the Poás Laguna Caliente (36.1°C - 56°C, pH = 0.55 - 0.74), nowadays the Poás hot lake is the most active crater lake in the world, with more than 200 eruptions only on 2010. One of the most studied cold crater lakes is Irazú (13°C, pH = 3.5), that used to contain bubbling and clear areas of upwelling involving CO2 liberation and subaqueous fumaroles with temperatures up to 50°C, but since 2005 the lake presents an important descend until April 2010 when it disappeared. On February 9, 2003, Irazú's lake underwent a drastic change of color, from clear green to mustard with reddish loops, similar to the color of the waters of Lake Nyos after the gas burst of August 1986. Other studied cold lakes include Botos, Chato, and Tenorio, all at the summit of Quaternary volcanoes as well as Barva and Danta, located in recent pyroclastic cones. Some cold lakes are located in Holocene maar-type explosion craters, among them are Congo, Bosque Alegre, Hule, and Río Cuarto. These last two have undergone repeated rapid reddish color changes over the last 10 years, in association with fish kills and the liberation of apparently sulfurous scents. On March 2010, University of Costa Rica was the host of the 7th Workshop on Volcanic Lakes, part of the Commission of Volcanic Lakes of the IAVCEI, 51 participants from 14 countries attended the workshop; they presented 27 talks and 17 posters, also they visited and sample 4 of the lakes mentioned above (Botos, Irazú, Río Cuarto and Hule). Level of Study: 1: few or no data, 2: regular, 3: acceptable

  17. 新疆乌伦古湖浮游植物群落结构%Phytoplankton community structure in Lake Ulungur in Xinjiang Uygur Autonomous Region

    Institute of Scientific and Technical Information of China (English)

    刘宇; 郝志才; 沈建忠; 李鸿; 赵永晶; 马徐发; 刘其根; 江敏; 董攸; 刘军

    2009-01-01

    于2006年11月至2007年7月按季度对乌伦古湖浮游植物进行了取样调查,共发现浮游藻类164种(包括若干未定名种),隶属于8门90属,其中Anabaena bergii为新疆新记录种,两种硅藻Chaetocerns sp.和Thalassionema sp.属于海产种类.各季种类组成均以绿藻门和硅藻门为主,蓝藻门和裸藻门次之,甲藻门、金藻门、黄藻门、隐藻门种类均比较少.秋季种类最多,有141种;其次是夏季和春季,分别为128种和121种;冬季种类最少,仅有95种.中华小尖头藻、微小四角藻、小形月牙藻、小球藻及尖针杆藻为全年可见优势种;肘状针杆藻在春季、夏季和秋季构成优势种群;扭曲蹄形藻和椭圆小球藻仅在夏季构成优势种群,而水溪绿球藻和粗刺四棘藻仅在冬季构成优势种群.藻类生物量周年变动模式为单峰型,生物量的峰值出现在夏季(6.77mg/L).最低值出现在冬季(1.45mg/L).结合历史资料分析发现,30年来,乌伦古湖浮游藻类不仅在种类组成上发生了明显的变化,在数量上也显著着一定的增长,并以绿藻和硅藻类群的增长最为显著.%The phytoplankton of Lake Uhmgur was investigated seasonally from November, 2006 to July, 2007. A total of 164 phytoplankton species (including a number of unconfirmed species) was detected, which belonged to 90 genera, 8 phylum. Among them, Anabaena bergii was a new record species of cyanophyta in Xinjiang Uygur Autonomous Region, and two species of bacillariophyta, Chaetoceros sp. and Thalassionema sp., belonged to marine algal. In each season, the phytoplankton composition was dominated by Chlorophyta aad Bacillariophyta, secondly dominated by Cyanophyta, Euglenophyta, Xanthophyta, Chrysophyta, Cryptophyta and Pyrrophyta. The number of phytoplankton species was the highest in autumn (141 species), followed by the summer (128 species) aad spring (121 species), the lowest in winter (95 species). There was an obvious seasonal

  18. Radiochronology of lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Erten, H.N. [Bilkent Univ., Ankara (Turkey). Dept. of Chemistry

    1997-01-01

    Sediment cores from Lakes Zurich, Constance, from the Sea of Marmara and from southern Turkey, northern Cyprus and eastern Spain were dated using natural {sup 210}Pb, fallout {sup 137}Cs and cosmic-ray produced {sup 7}Be radionuclides. Constant activity regions in the uppermost sections of sediments from Lake Zurich and the Sea of Marmara were attributed to post-depositional mobility of {sup 210}Pb in the former case and to bioturbation in the latter. A serious discrepancy exists between the {sup 210}Pb dating of Sea of Marmara sediments and those obtained by organic carbon based methods. The elements Zn, Cu, P and Pb were enriched in the upper sections of the sediment cores corresponding to the last 200 years. The increased metallurgical activities as a result of reforms in the Ottoman Army during the 18th century could be the most likely cause. (Author).

  19. Research on Petrologic Character of Nephrite Jade From Baikal Lake Region in Russia%俄罗斯贝加尔湖地区软玉的岩石学特征研究

    Institute of Scientific and Technical Information of China (English)

    张晓晖; 吴瑞华; 王乐燕

    2001-01-01

    通过对俄罗斯贝加尔湖地区软玉的化学成分、矿物组成、结构构造等方面的 研究 ,对其成因机制进行了初步探讨,较系统地总结了俄罗斯贝加尔湖地区软玉的岩石学特征 , 并将其与中国新疆的和田玉进行了初步对比。%The chemical composition, m ineral component, texture and structure type of nephrite from Baikal Lake region in Russia are studied, and the genesis of nephrite jade is discussed. The petrolo gical characteristics of nephrite jade from Baikal Lake region in R ussian are introduced systematically, and compared with Hetian jade from Xinjiang, which will be useful to the exploi tation of nephrite and for the development of the nephrite market.

  20. 洞庭湖主要生态环境问题变化分析%CHANGES OF MAJOR ECOLOGICAL AND ENVIRONMENTAL ISSUES IN DONGTING LAKE REGION

    Institute of Scientific and Technical Information of China (English)

    孙占东; 黄群; 姜加虎

    2011-01-01

    With the evolution of sediment,hydrological regime and pollution,major environmental issues have gradually changed around Dongting Lake in recent decades.Especially under the impacts from the Three Gorges Project,returning farmland to lake project and the increasing of climate extremes,Dongting Lake is undergoing low water level occurrences.The water level dropped 2.03 and 2.11 m at the outlet of the lake in 2006 and 2009 respectively,caused by the water storage of Three Gorges Reservoir.The water quality has deteriorated from grade Ⅳ to grade Ⅴsince 2008.Low water level accelerated the change in wetland structure and the degradation in wetland function.Invasive plant has threatened the biodiversity and the stability of habitat.Due to continuous decrease in sediment discharge,Dongting Lake,for the first time,changed from trapping to supplying net sediment to the Yangtze River in 2006.The environmental conflict around Dongting Lake is changing from flood dominated to flood and drought coexisted.These environmental changes have reflected the social structure transformed from traditional agriculture to a comprehensive development in agriculture,forestry and industry,as well as changes in the lake-catchment interaction.%通过对近几十年来洞庭湖水情、泥沙、污染和湿地生态等不同方面问题的回顾分析,认为在三峡工程建设、洞庭湖退田还湖和极端天气事件影响下,洞庭湖主要生态环境问题发生了一些变化。由于气候干旱化,加之三峡水库蓄水影响,导致洞庭湖入湖水量季节性减少,湖区水位下降,干旱期延长。模拟显示2006和2009年三峡秋季蓄水使洞庭湖出口水位平均下降2.03和2.11 m;由于三口来沙急剧减少,入湖泥沙打破了以淤积为主的模式,2006年洞庭湖第一次出现从拦蓄泥沙变成向长江净输出泥沙。低水位运行不仅对洲滩演进和湖泊水质带来影响,也加速了对湖滩的开发利用,外来物种的发展威

  1. Restoration in northern Lake Gehu, a eutrophic lake in China

    Science.gov (United States)

    Wu, Xiaodong; Li, Wenchao; Pan, Jizheng; Ma, Shuzhan; Chen, Bingfa; He, Shangwei

    2017-02-01

    Lake Gehu is a severely eutrophic lake in southeast China. A series of restoration measures have been implemented since 2009 in northern Lake Gehu. This study compared aquatic plants, water quality, sediment, and phytoplankton between restoration and control areas to investigate the effect of restoration measures. The results demonstrated that aquatic macrophyte coverage increased from 0% to 10.6%; mean TP, TN, and CODMn concentrations increased by 50.0%, 42.4%, and 40.8%, respectively, compared with those before the measures were carried out; the mean Secchi depth (SD) increased to 42.5 cm, which is 1.4 times higher than that before restoration; the mean euphotic depth (Zeu) in the summer increased from 91 to 130 cm; the mean chl a concentration decreased from 34.8 to 20.2 μg/L, compared with that before restoration; the Shannon-Wiener index of phytoplankton increased by 28.7%. The mean TP and TN concentrations in sediments decreased by 63.8% and 52.4%, respectively, compared with that before dredging. These results indicate that the restoration in northern Lake Gehu was effective. To complete the transformation from an algae- to a macrophyte-stable state within the region, further measures must be adopted. This restoration of a eutrophic lake can serve as a reference for similar eutrophic lakes.

  2. Analysis on Energy Value of Wetland Ecosystem of Nansi Lake in Shandong Province of China and Regional Development%南四湖湿地生态系统能值分析与区域发展

    Institute of Scientific and Technical Information of China (English)

    梁春玲; 谷胜利

    2012-01-01

    Adopting the theories and methods of Energy Analysis established by H.T.Odum,the average yearly energy input-output of wetland ecosystem of Nansi Lake is calculated and the energy analysis chart is drawn to evaluate the energy flow and the economic value of the lake.And the structure and function of Nansi Lake wetland ecosystem is analyzed as a whole.The result shows that the amount of the input solar value(including the sun,wind and rain) of the Nansi Lake is 1.11×1021sej,and the output solar value is 1.73×1020sej.The primary productivity is1.61×1020sej.Non-renewable energy or resources(including sediment and water) is 1.03×1021sej.At the same time,the ecological benefits of aquatic vascular plants and fish of the Nansi Lake are significant.Energy investment ratio of the lake is 0.000 9.Net energy yield is 165.23 and environmental loading rate is 14.22.High net energy yield and environmental loading rates show that Nansi Lake wetland ecosystem has a great contribution to local economy.The regional economic development level is low and vastly depends on nature environment.%为评估南四湖湿地生态系统的能量流动状况及其经济价值,采用H.T.Odum建立的能值分析理论,计算南四湖湿地生态系统多年平均的能值投入/产出,绘制南四湖湿地生态系统能值图,分析南四湖湿地生态系统结构和功能的整体特征。结果表明:南四湖湿地的投入量太阳能值为1.11×1021sej,产出量太阳能值为1.73×1020sej,初级生产力为1.61×1020sej,不可再生能源或资源(包括底泥和水体)为1.03×1021sej;同时,南四湖在水生维管束植物、以及鱼类产出方面生态效益价值显著。南四湖湿地能值投资率为0.000 9,净能值产出率为165.23,环境负载率为14.22,能值投资率低,净能值产出率高,环境负载率高,表明南四湖湿地对经济的贡献很大,区域经济发展水平较低,对环境依赖性强。

  3. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  4. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  5. Hydrography - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  6. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  7. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  8. Designated Wildlife Lakes - points

    Data.gov (United States)

    Minnesota Department of Natural Resources — This is a point shapefile of Designated Wildlife Lakes in Minnesota. This shapefile was created by converting lake polygons from the Designated Wildlife Lakes...

  9. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  10. Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2008-01-01

    Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakesLakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO2 occur, and an accumulation of CO2 in the deep water body must be taken into account.

    Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO2 degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

  11. Chrysophyte cysts from lake sediments reveal the submillennial winter/spring climate variability in the northwestern Mediterranean region throughout the Holocene

    Energy Technology Data Exchange (ETDEWEB)

    Pla, Sergi [Queen' s University, PEARL, Department of Biology, Kingston, ON (Canada); Catalan, Jordi [CSIC, CSIC-UB Limnology Group, Centre for Advanced Studies of Blanes (CEAB), Blanes (Spain)

    2005-02-01

    In the last decade, much effort was dedicated to the reconstruction of past climate at high temporal resolution. Here, we show the suitability of chrysophyte cysts from lake sediments for revealing continental climate variability when used in sensitive sites, such as those in high mountains. We demonstrate that altitude is a main factor influencing the present distribution of chrysophytes and develop a transfer function to evaluate the local ''altitude anomaly'' on a lake site throughout time. Based on our knowledge of chrysophyte ecology, the altitude anomalies are interpreted as winter/spring climate signatures. The method was applied to a Holocene record from a lake in the Pyrenees showing submillennial climatic variability in this northwestern Mediterranean zone. A warming trend was present from the early Holocene to 4 kyear BP. Comparison with pollen-based reconstructions of summer temperatures denoted a contrasting decrease in continentality between the two parts of the Holocene. Oscillations of 1 cycle per ca. 2,000 years appeared throughout the record. The warmest Holocene winters were recorded during the Medieval Warm Period at ca. AD900 and 450 and the Roman Warm Period (2.7-2.4 kyear BP). Winters in the period AD1,050-1,175 were inferred to be as cold as in the Little Ice Age. The period between 3 and 7 kyear BPshowed lower intensity in the fluctuations than in early and late Holocene. The cold event, 8,200 years ago, appeared embedded in a warm fluctuation. Another cold fluctuation was recorded around 9 kyear BP, which is in agreement with Irish and Greenland records. (orig.)

  12. The influence of particles recycling on the geochemistry of sediments in a large tropical dam lake in the Amazonian region, Brazil

    Science.gov (United States)

    Fonseca, Rita; Pinho, Catarina; Oliveira, Manuela

    2016-12-01

    As a result of over-erosion of soils, the fine particles, which contain the majority of nutrients, are easily washed away from soils, which become deficient in a host of components, accumulating in lakes. On one hand, the accumulation of nutrients-rich sediments are a problem, as they affect the quality of the overlying water and decrease the water storage capacity of the system; on the other hand, sediments may constitute an important resource, as they are often extremely rich in organic and inorganic nutrients in readily available forms. In the framework of an extensive work on the use of rock related materials to enhance the fertility of impoverish soils, this study aimed to evaluate the role on the nutrients cycle, of particles recycling processes from the watershed to the bottom of a large dam reservoir, at a wet tropical region under high weathering conditions. The study focus on the mineralogical transformations that clay particles undergo from the soils of the drainage basin to their final deposition within the reservoir and their influence in terms of the geochemical characteristics of sedimen