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Sample records for reservoir watershed south-central

  1. Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

    Science.gov (United States)

    Mau, D.P.

    2001-01-01

    Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis

  2. Historical contributions of phosphorus from natural and agricultural sources and implications for stream water quality, Cheney Reservoir watershed, south-central Kansas

    Science.gov (United States)

    Pope, Larry M.; Milligan, Chad R.; Mau, David Phillip

    2002-01-01

    An examination of soil cores collected from 43 nonagricultural coring sites in the Cheney Reservoir watershed of south-central Kansas was conducted by the U.S. Geological Survey in September 1999. The cores were collected as part of an ongoing cooperative study with the city of Wichita, Kansas. The 43 sites (mostly cemeteries) were thought to have total phosphorus concentrations in the soil that are representative of natural conditions (unaffected by human activity). The purpose of this report is to present the analysis and evaluation of these soil cores, to quantify the phosphorus contributions to Cheney Reservoir from natural and agricultural sources, and to provide estimates of stream-water-quality response to natural concentrations of total phosphorus in the soil. Analysis of soil cores from the 43 sites produced natural concentrations of total phosphorus that ranged from 74 to 539 milligrams per kilogram with a median concentration of 245 milligrams per kilogram in 2-inch soil cores and from 50 to 409 milligrams per kilogram with a median concentration of 166 milligrams per kilogram in 8-inch soil cores. Natural concentrations of total phosphorus in soil were statistically larger in samples from coring sites in the eastern half of the watershed than in samples from coring sites in the western half of the watershed. This result partly explains a previously determined west-to-east increase in total phosphorus yields in streams of the Cheney Reservoir watershed. A comparison of total phosphorus concentrations in soil under natural conditions to the historical mean total phosphorus concentration in agriculturally enriched bottom sediment in Cheney Reservoir indicated that agricultural activities within the watershed have increased total phosphorus concentrations in watershed soil that is transported in streams to about 2.9 times natural concentrations. Retention efficiencies for phosphorus and sediment historically transported to Cheney Reservoir were calculated

  3. Watershed trend analysis and water-quality assessment using bottom-sediment cores from Cheney Reservoir, south-central Kansas

    Science.gov (United States)

    Pope, Larry M.

    1998-01-01

    An examination of Cheney Reservoir bottom sediment was conducted in August 1997 to describe long-term trends and document the occurrence of selected constituents at concentrations that may be detrimental to aquatic organisms. Average concentrations of total phosphorus in bottom-sediment cores ranged from 94 to 674 milligrams per kilogram and were statistically related to silt- and (or) clay-size particles. Results from selected sampling sites in Cheney Reservoir indicate an increasing trend in total phosphorus concentrations. This trend is probably of nonpoint-source origin and may be related to an increase in fertilizer sales in the area, which more than doubled between 1965 and 1996, and to livestock production. Few organochlorine compounds were detected in bottom-sediment samples from Cheney Reservoir. DDT, its degradation products DDD and DDE, and dieldrin had detectable concentrations in the seven samples that were analyzed. DDT and DDD were each detected in one sample at concentrations of 1.0 and 0.65 microgram per kilogram, respectively. By far, the most frequently detected organochlorine insecticide was DDE, which was detected in all seven samples, ranging in concentration from 0.31 to 1.3 micrograms per kilogram. A decreasing trend in DDE concentrations was evident in sediment-core data from one sampling site. Dieldrin was detected in one sample from each of two sampling sites at concentrations of 0.21 and 0.22 micrograms per kilogram. Polychlorinated biphenyls were not detected in any bottom-sediment sample analyzed. Selected organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides were analyzed in 18 bottom-sediment samples. Of the 23 pesticides analyzed, only the acetanilide herbicide metolachlor was detected (in 22 percent of the samples). Seven bottom-sediment samples were analyzed for major metals and trace elements. The median and maximum concentrations of arsenic and chromium, the maximum concentration of copper, and all

  4. Twelve Years of Monitoring Phosphorus and Suspended-Solids Concentrations and Yields in the North Fork Ninnescah River above Cheney Reservoir, South-Central Kansas 1997-2008

    Science.gov (United States)

    Stone, Mandy L.; Graham, Jennifer L.; Ziegler, Andrew C.

    2009-01-01

    Cheney Reservoir, located on the North Fork Ninnescah River in south-central Kansas, is the primary water supply for the city of Wichita and an important recreational resource. Concerns about taste-and-odor occurrences in Cheney Reservoir have drawn attention to potential pollutants, including total phosphorus (TP) and total suspended solids (TSS). July 2009 was the 15th anniversary of the establishment of the Cheney Reservoir Watershed pollution management plan. The U.S. Geological Survey (USGS), in cooperation with the city of Wichita, has collected water-quality data in the basin since 1996, and has monitored water quality continuously on the North Fork Ninnescah River since 1998. This fact sheet describes 12 years (1997-2008) of computed TP and TSS data and compares these data with water-quality goals for the North Fork Ninnescah River, the main tributary to Cheney Reservoir.

  5. NYC Reservoirs Watershed Areas (HUC 12)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This NYC Reservoirs Watershed Areas (HUC 12) GIS layer was derived from the 12-Digit National Watershed Boundary Database (WBD) at 1:24,000 for EPA Region 2 and...

  6. Optimizing Fracture Treatments in a Mississippian "Chat" Reservoir, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    K. David Newell; Saibal Bhattacharya; Alan Byrnes; W. Lynn Watney; Willard Guy

    2005-10-01

    This project is a collaboration of Woolsey Petroleum Corporation (a small independent operator) and the Kansas Geological Survey. The project will investigate geologic and engineering factors critical for designing hydraulic fracture treatments in Mississippian ''chat'' reservoirs. Mississippian reservoirs, including the chat, account for 159 million m3 (1 billion barrels) of the cumulative oil produced in Kansas. Mississippian reservoirs presently represent {approx}40% of the state's 5.6*106m3 (35 million barrels) annual production. Although geographically widespread, the ''chat'' is a heterogeneous reservoir composed of chert, cherty dolomite, and argillaceous limestone. Fractured chert with micro-moldic porosity is the best reservoir in this 18- to 30-m-thick (60- to 100-ft) unit. The chat will be cored in an infill well in the Medicine Lodge North field (417,638 m3 [2,626,858 bbls] oil; 217,811,000 m3 [7,692,010 mcf] gas cumulative production; discovered 1954). The core and modern wireline logs will provide geological and petrophysical data for designing a fracture treatment. Optimum hydraulic fracturing design is poorly defined in the chat, with poor correlation of treatment size to production increase. To establish new geologic and petrophysical guidelines for these treatments, data from core petrophysics, wireline logs, and oil-field maps will be input to a fracture-treatment simulation program. Parameters will be established for optimal size of the treatment and geologic characteristics of the predicted fracturing. The fracturing will be performed and subsequent wellsite tests will ascertain the results for comparison to predictions. A reservoir simulation program will then predict the rate and volumetric increase in production. Comparison of the predicted increase in production with that of reality, and the hypothetical fracturing behavior of the reservoir with that of its actual behavior, will serve as tests of

  7. Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014

    Science.gov (United States)

    MacCoy, Dorene E.; Short, Terry M.

    2016-09-28

    Assessments of streamflow (discharge) parameters, water quality, physical habitat, and biological communities were completed between May and September 2014 as part of a monitoring program in the Big Wood River watershed of south-central Idaho. The sampling was conducted by the U.S. Geological Survey in cooperation with Blaine County, Trout Unlimited, the Nature Conservancy, and the Wood River Land Trust to help identify the status of aquatic resources at selected locations in the watershed. Information in this report provides a basis with which to evaluate and monitor the long-term health of the Big Wood River and its major tributaries. Sampling sites were co-located with existing U.S. Geological Survey streamgaging stations: three on the main stem Big Wood River and four on the North Fork Big Wood River (North Fork), Warm Springs Creek (Warm Sp), Trail Creek (Trail Ck), and East Fork Big Wood River (East Fork) tributaries.The analytical results and quality-assurance information for water quality, physical habitat, and biological community samples collected at study sites during 2 weeks in September 2014 are summarized. Water-quality data include concentrations of major nutrients, suspended sediment, dissolved oxygen, and fecal-coliform bacteria. To assess the potential effects of nutrient enrichment on algal growth, concentrations of periphyton biomass (chlorophyll-a and ash free dry weight) in riffle habitats were determined at each site. Physical habitat parameters include stream channel morphology, habitat volume, instream structure, substrate composition, and riparian vegetative cover. Biological data include taxa richness, abundance, and stream-health indicator metrics for macroinvertebrate and fish communities. Statistical summaries of the water-quality, habitat, and biological data are provided along with discussion of how these findings relate to the health of aquatic resources in the Big Wood River watershed.Seasonal discharge patterns using statistical

  8. Water quality, sources of nitrate, and chemical loadings in the Geronimo Creek and Plum Creek watersheds, south-central Texas, April 2015–March 2016

    Science.gov (United States)

    Lambert, Rebecca B.; Opsahl, Stephen P.; Musgrove, MaryLynn

    2017-12-22

    Located in south-central Texas, the Geronimo Creek and Plum Creek watersheds have long been characterized by elevated nitrate concentrations. From April 2015 through March 2016, an assessment was done by the U.S. Geological Survey, in cooperation with the Guadalupe-Blanco River Authority and the Texas State Soil and Water Conservation Board, to characterize nitrate concentrations and to document possible sources of elevated nitrate in these two watersheds. Water-quality samples were collected from stream, spring, and groundwater sites distributed across the two watersheds, along with precipitation samples and wastewater treatment plant (WWTP) effluent samples from the Plum Creek watershed, to characterize endmember concentrations and isotopic compositions from April 2015 through March 2016. Stream, spring, and groundwater samples from both watersheds were collected during four synoptic sampling events to characterize spatial and temporal variations in water quality and chemical loadings. Water-quality and -quantity data from the WWTPs and stream discharge data also were considered. Samples were analyzed for major ions, selected trace elements, nutrients, and stable isotopes of water and nitrate.The dominant land use in both watersheds is agriculture (cultivated crops, rangeland, and grassland and pasture). The upper part of the Plum Creek watershed is more highly urbanized and has five major WWTPs; numerous smaller permitted wastewater outfalls are concentrated in the upper and central parts of the Plum Creek watershed. The Geronimo Creek watershed, in contrast, has no WWTPs upstream from or near the sampling sites.Results indicate that water quality in the Geronimo Creek watershed, which was evaluated only during base-flow conditions, is dominated by groundwater, which discharges to the stream by numerous springs at various locations. Nitrate isotope values for most Geronimo Creek samples were similar, which indicates that they likely have a common source (or

  9. Small Reservoir Impact on Simulated Watershed-Scale Nutrient Yield

    Directory of Open Access Journals (Sweden)

    Shane J. Prochnow

    2007-01-01

    Full Text Available The soil and water assessment tool (SWAT is used to assess the influence of small upland reservoirs (PL566 on watershed nutrient yield. SWAT simulates the impact of collectively increasing and decreasing PL566 magnitudes (size parameters on the watershed. Totally removing PL566 reservoirs results in a 100% increase in total phosphorus and an 82% increase in total nitrogen, while a total maximum daily load (TMDL calling for a 50% reduction in total phosphorus can be achieved with a 500% increase in the magnitude of PL566s in the watershed. PL566 reservoirs capture agriculture pollution in surface flow, providing long-term storage of these constituents when they settle to the reservoir beds. A potential strategy to reduce future downstream nutrient loading is to enhance or construct new PL566 reservoirs in the upper basin to better capture agricultural runoff.

  10. Simulation of streamflow and estimation of ground-water recharge in the Upper Cibolo Creek Watershed, south-central Texas, 1992-2004

    Science.gov (United States)

    Ockerman, Darwin J.

    2007-01-01

    A watershed model (Hydrological Simulation Program?FORTRAN) was developed, calibrated, and tested by the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, San Antonio River Authority, San Antonio Water System, and Guadalupe-Blanco River Authority, to simulate streamflow and estimate ground-water recharge in the upper Cibolo Creek watershed in south-central Texas. Rainfall, evapotranspiration, and streamflow data were collected during 1992?2004 for model calibrations and simulations. Estimates of average ground-water recharge during 1992?2004 from simulation were 79,800 acre-feet (5.47 inches) per year or about 15 percent of rainfall. Most of the recharge (about 74 percent) occurred as infiltration of streamflow in Cibolo Creek. The remaining recharge occurred as diffuse infiltration of rainfall through the soil and rock layers and karst features. Most recharge (about 77 percent) occurred in the Trinity aquifer outcrop. The remaining 23 percent occurred in the downstream part of the watershed that includes the Edwards aquifer recharge zone (outcrop). Streamflow and recharge in the study area are greatly influenced by large storms. Storms during June 1997, October 1998, and July 2002 accounted for about 11 percent of study-area rainfall, 61 percent of streamflow, and 16 percent of the total ground-water recharge during 1992?2004. Annual streamflow and recharge also were highly variable. During 1999, a dry year with about 16 inches of rain and no measurable runoff at the watershed outlet, recharge in the watershed amounted to only 0.99 inch compared with 13.43 inches during 1992, a relatively wet year with about 54 inches of rainfall. Simulation of flood-control/recharge-enhancement structures showed that certain structures might reduce flood peaks and increase recharge. Simulation of individual structures on tributaries showed relatively little effect. Larger structures on the main stem of Cibolo Creek were more effective than structures

  11. Role of lake regulation on glacier fed rivers in enhancing salmon productivity: The Cook Inlet watershed south central Alaska, USA

    Science.gov (United States)

    Hupp, C.R.

    2000-01-01

    Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation. Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat. Copyright ?? 2000 John Wiley & Sons, Ltd.Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet

  12. Identifying agricultural land management successes and water quality improvements at the sub-watershed scale: A case study in south-central Minnesota

    Science.gov (United States)

    Perry, M.; Triplett, L.; Smith, C.; Westfield, J.; Clause, C.

    2017-12-01

    In agricultural regions with highly-impacted water quality, it can be challenging to generate local motivation for water improvement efforts. Although the problem is daunting, and the magnitude of each individual's efforts may be indistinguishable in a mainstem stream, we may be able to detect incremental improvements earlier within a sub-watershed. In Seven Mile Creek, a small watershed in south-central Minnesota, we monitored at the sub-watershed scale to search for evidence of intermediate improvements during a years-long effort to reduce nutrient and sediment loads. The watershed is 9300 hectares with approximately 95% committed to corn and soybeans. Subwatershed 1 (SW1) is 4030 hectares and subwatershed 2 (SW2) is 3690 hectares (43% and 40% of the watershed area, respectively). In both subwatersheds, ubiquitous subsurface drain tile quickly drains water from the land, shunting it into tributaries and the mainstem which then have flashy storm responses. In 2016-2017, the two subwatersheds differed in water quality and storm response, despite nearly identical size, topography, climate, and geology. For example, during large storm events in 2016, total suspended sediment (TSS) concentrations were measured as high as 113 mg L-1 in subwatershed 1 and 79 mg L-1 in subwatershed 2. However, the annual average TSS concentration was 2 mg L-1 in SW1 and 3 mg L-1 in SW2, resulting in a higher loading from SW2. In contrast, the annual average nitrate concentration was higher in SW1 than SW2 (28 mg L-1 and 20 mg L-1, respectively). We determined that the difference is likely due to differences in soil type, cropping practices, or recent best management practice (BMP) implementation. While a few landowners have taken substantial actions to implement BMPs, others remain skeptical about the sources of and potential solutions for pollution in this creek. In SW1 there has been more effective management of water flow and sediment mobilization, while in SW2 nitrate is the success

  13. Simulation of streamflow, evapotranspiration, and groundwater recharge in the lower San Antonio River Watershed, South-Central Texas, 2000-2007

    Science.gov (United States)

    Lizarraga, Joy S.; Ockerman, Darwin J.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, the Evergreen Underground Water Conservation District, and the Goliad County Groundwater Conservation District, configured, calibrated, and tested a watershed model for a study area consisting of about 2,150 square miles of the lower San Antonio River watershed in Bexar, Guadalupe, Wilson, Karnes, DeWitt, Goliad, Victoria, and Refugio Counties in south-central Texas. The model simulates streamflow, evapotranspiration (ET), and groundwater recharge using rainfall, potential ET, and upstream discharge data obtained from National Weather Service meteorological stations and USGS streamflow-gaging stations. Additional time-series inputs to the model include wastewater treatment-plant discharges, withdrawals for cropland irrigation, and estimated inflows from springs. Model simulations of streamflow, ET, and groundwater recharge were done for 2000-2007. Because of the complexity of the study area, the lower San Antonio River watershed was divided into four subwatersheds; separate HSPF models were developed for each subwatershed. Simulation of the overall study area involved running simulations of the three upstream models, then running the downstream model. The surficial geology was simplified as nine contiguous water-budget zones to meet model computational limitations and also to define zones for which ET, recharge, and other water-budget information would be output by the model. The model was calibrated and tested using streamflow data from 10 streamflow-gaging stations; additionally, simulated ET was compared with measured ET from a meteorological station west of the study area. The model calibration is considered very good; streamflow volumes were calibrated to within 10 percent of measured streamflow volumes. During 2000-2007, the estimated annual mean rainfall for the water-budget zones ranged from 33.7 to 38.5 inches per year; the estimated annual mean rainfall for the entire

  14. [Effects of Three Gorges Reservoir impoundment on the wetland ecosystem service value of Dongting Lake, South-central China].

    Science.gov (United States)

    Li, Jing-Bao; Dai, Yong; Yin, Ri-Xin; Yang, Yan; Li, Yu-dan; Wang, Ke-ying

    2013-03-01

    Based on the field investigation and measurement, and by using the monetary method, this paper estimated the wetland ecosystem service value of Dongting Lake before and after the impoundment of Three Gorges Reservoir (in 1996 and 2010, respectively). After the impoundment, the total ecosystem service value increased from 156.69x10(8) yuan in 1996 to 177.11x10(8) yuan in 2010. The main services value in 1996 was in the order of flood storage and regulation > water storage and supply > air regulation > scientific research and education, while that in 2010 was leisure tourism > shipping transportation > air regulation > water storage and supply. In the total service value of the wetland ecosystem, the direct value associated with water decreased from 110. 85x10(8) in 1996 to 27.47x10(8) in 2010, with a decrement of 75.2%. Though the proportion of the direct value in the production and supply of material products had somewhat increase, the indirect value in ecological environment regulation and maintenance and in culture and society still maintained at about 80% of the total value. In addition to climate factors, the impoundment of Three Gorges Reservoir and the reduction of water and sediment from Yangtze River to the Lake were the crucial reasons leading to the changes of the wetland ecosystem service value of Dongting Lake.

  15. Fort Cobb Reservoir Watershed, Oklahoma and Thika River Watershed, Kenya Twinning Pilot Project

    Science.gov (United States)

    Moriasi, D.; Steiner, J.; Arnold, J.; Allen, P.; Dunbar, J.; Shisanya, C.; Gathenya, J.; Nyaoro, J.; Sang, J.

    2007-12-01

    The Fort Cobb Reservoir Watershed (FCRW) (830 km2) is a watershed within the HELP Washita Basin, located in Caddo and Washita Counties, OK. It is also a benchmark watershed under USDA's Conservation Effects Assessment Project, a national project to quantify environmental effects of USDA and other conservation programs. Population in south-western Oklahoma, in which FCRW is located, is sparse and decreasing. Agricultural focuses on commodity production (beef, wheat, and row crops) with high costs and low margins. Surface and groundwater resources supply public, domestic, and irrigation water. Fort Cobb Reservoir and contributing stream segments are listed on the Oklahoma 303(d) list as not meeting water quality standards based on sedimentation, trophic level of the lake associated with phosphorus loads, and nitrogen in some stream segments in some seasons. Preliminary results from a rapid geomorphic assessment results indicated that unstable stream channels dominate the stream networks and make a significant but unknown contribution to suspended-sediment loadings. Impairment of the lake for municipal water supply, recreation, and fish and wildlife are important factors in local economies. The Thika River Watershed (TRW) (867 km2) is located in central Kenya. Population in TRW is high and increasing, which has led to a poor land-population ratio with population densities ranging from 250 people/km2 to over 500 people/km2. The poor land-population ratio has resulted in land sub-division, fragmentation, over- cultivation, overgrazing, and deforestation which have serious implications on soil erosion, which poses a threat to both agricultural production and downstream reservoirs. Agricultural focuses mainly on subsistence and some cash crops (dairy cattle, corn, beans, coffee, floriculture and pineapple) farming. Surface and groundwater resources supply domestic, public, and hydroelectric power generation water. Thika River supplies 80% of the water for the city of

  16. Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

    Science.gov (United States)

    Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.

    2017-12-01

    New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P

  17. An integrated multi-level watershed-reservoir modeling system for examining hydrological and biogeochemical processes in small prairie watersheds.

    Science.gov (United States)

    Zhang, Hua; Huang, Guo H; Wang, Dunling; Zhang, Xiaodong; Li, Gongchen; An, Chunjiang; Cui, Zheng; Liao, Renfei; Nie, Xianghui

    2012-03-15

    Eutrophication of small prairie reservoirs presents a major challenge in water quality management and has led to a need for predictive water quality modeling. Studies are lacking in effectively integrating watershed models and reservoir models to explore nutrient dynamics and eutrophication pattern. A water quality model specific to small prairie water bodies is also desired in order to highlight key biogeochemical processes with an acceptable degree of parameterization. This study presents a Multi-level Watershed-Reservoir Modeling System (MWRMS) to simulate hydrological and biogeochemical processes in small prairie watersheds. It integrated a watershed model, a hydrodynamic model and an eutrophication model into a flexible modeling framework. It can comprehensively describe hydrological and biogeochemical processes across different spatial scales and effectively deal with the special drainage structure of small prairie watersheds. As a key component of MWRMS, a three-dimensional Willows Reservoir Eutrophication Model (WREM) is developed to addresses essential biogeochemical processes in prairie reservoirs and to generate 3D distributions of various water quality constituents; with a modest degree of parameterization, WREM is able to meet the limit of data availability that often confronts the modeling practices in small watersheds. MWRMS was applied to the Assiniboia Watershed in southern Saskatchewan, Canada. Extensive efforts of field work and lab analysis were undertaken to support model calibration and validation. MWRMS demonstrated its ability to reproduce the observed watershed water yield, reservoir water levels and temperatures, and concentrations of several water constituents. Results showed that the aquatic systems in the Assiniboia Watershed were nitrogen-limited and sediment flux played a crucial role in reservoir nutrient budget and dynamics. MWRMS can provide a broad context of decision support for water resources management and water quality

  18. Continuous real-time water-quality monitoring and regression analysis to compute constituent concentrations and loads in the North Fork Ninnescah River upstream from Cheney Reservoir, south-central Kansas, 1999–2012

    Science.gov (United States)

    Stone, Mandy L.; Graham, Jennifer L.; Gatotho, Jackline W.

    2013-01-01

    Cheney Reservoir, located in south-central Kansas, is the primary water supply for the city of Wichita. The U.S. Geological Survey has operated a continuous real-time water-quality monitoring station since 1998 on the North Fork Ninnescah River, the main source of inflow to Cheney Reservoir. Continuously measured water-quality physical properties include streamflow, specific conductance, pH, water temperature, dissolved oxygen, and turbidity. Discrete water-quality samples were collected during 1999 through 2009 and analyzed for sediment, nutrients, bacteria, and other water-quality constituents. Regression models were developed to establish relations between discretely sampled constituent concentrations and continuously measured physical properties to compute concentrations of those constituents of interest that are not easily measured in real time because of limitations in sensor technology and fiscal constraints. Regression models were published in 2006 that were based on data collected during 1997 through 2003. This report updates those models using discrete and continuous data collected during January 1999 through December 2009. Models also were developed for four new constituents, including additional nutrient species and indicator bacteria. In addition, a conversion factor of 0.68 was established to convert the Yellow Springs Instruments (YSI) model 6026 turbidity sensor measurements to the newer YSI model 6136 sensor at the North Ninnescah River upstream from Cheney Reservoir site. Newly developed models and 14 years of hourly continuously measured data were used to calculate selected constituent concentrations and loads during January 1999 through December 2012. The water-quality information in this report is important to the city of Wichita because it allows the concentrations of many potential pollutants of interest to Cheney Reservoir, including nutrients and sediment, to be estimated in real time and characterized over conditions and time scales that

  19. Twenty years of water-quality studies in the Cheney Reservoir Watershed, Kansas, 1996-2016

    Science.gov (United States)

    Graham, Jennifer L.; Foster, Guy M.; Kramer, Ariele R.

    2017-03-31

    Since 1996, the U.S. Geological Survey (USGS), in cooperation with the City of Wichita, has done studies in the Cheney Reservoir watershed to understand environmental effects on water-quality conditions. Early studies (1996–2001) determined subwatershed sources of contaminants, nutrient and sediment loading to Cheney Reservoir, changes in reservoir sediment quality over time, and watershed sources of phosphorus. Later studies (2001–present) focused on nutrient and sediment concentrations and mass transport from the watershed; the presence of cyanobacteria, cyanotoxins, and taste-and-odor compounds in the reservoir; and development of regression models for real-time computations of water-quality constituents of interest that may affect drinking-water treatment. This fact sheet summarizes key results from studies done by the USGS during 1996–2016 in the Cheney Reservoir watershed and Cheney Reservoir.

  20. Upstream-downstream cooperation approach in Guanting Reservoir watershed.

    Science.gov (United States)

    Yang, Zhi-Feng; Zhang, Wen-Guo

    2005-01-01

    A case study is introduced and discussed concerning water dispute of misuse and pollution between up- and down-stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy.

  1. Simulation of streamflow and estimation of recharge to the Edwards aquifer in the Hondo Creek, Verde Creek, and San Geronimo Creek watersheds, south-central Texas, 1951-2003

    Science.gov (United States)

    Ockerman, Darwin J.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the San Antonio Water System, constructed three watershed models using the Hydrological Simulation Program—FORTRAN (HSPF) to simulate streamflow and estimate recharge to the Edwards aquifer in the Hondo Creek, Verde Creek, and San Geronimo Creek watersheds in south-central Texas. The three models were calibrated and tested with available data collected during 1992–2003. Simulations of streamflow and recharge were done for 1951–2003. The approach to construct the models was to first calibrate the Hondo Creek model (with an hourly time step) using 1992–99 data and test the model using 2000–2003 data. The Hondo Creek model parameters then were applied to the Verde Creek and San Geronimo Creek watersheds to construct the Verde Creek and San Geronimo Creek models. The simulated streamflows for Hondo Creek are considered acceptable. Annual, monthly, and daily simulated streamflows adequately match measured values, but simulated hourly streamflows do not. The accuracy of streamflow simulations for Verde Creek is uncertain. For San Geronimo Creek, the match of measured and simulated annual and monthly streamflows is acceptable (or nearly so); but for daily and hourly streamflows, the calibration is relatively poor. Simulated average annual total streamflow for 1951–2003 to Hondo Creek, Verde Creek, and San Geronimo Creek is 45,400; 32,400; and 11,100 acre-feet, respectively. Simulated average annual streamflow at the respective watershed outlets is 13,000; 16,200; and 6,920 acre-feet. The difference between total streamflow and streamflow at the watershed outlet is streamflow lost to channel infiltration. Estimated average annual Edwards aquifer recharge for Hondo Creek, Verde Creek, and San Geronimo Creek watersheds for 1951–2003 is 37,900 acrefeet (5.04 inches), 26,000 acre-feet (3.36 inches), and 5,940 acre-feet (1.97 inches), respectively. Most of the recharge (about 77 percent for the three watersheds

  2. Forecasting the remaining reservoir capacity in the Laurentian Great Lakes watershed

    Science.gov (United States)

    Alighalehbabakhani, Fatemeh; Miller, Carol J.; Baskaran, Mark; Selegean, James P.; Barkach, John H.; Dahl, Travis; Abkenar, Seyed Mohsen Sadatiyan

    2017-12-01

    Sediment accumulation behind a dam is a significant factor in reservoir operation and watershed management. There are many dams located within the Laurentian Great Lakes watershed whose operations have been adversely affected by excessive reservoir sedimentation. Reservoir sedimentation effects include reduction of flood control capability and limitations to both water supply withdrawals and power generation due to reduced reservoir storage. In this research, the sediment accumulation rates of twelve reservoirs within the Great Lakes watershed were evaluated using the Soil and Water Assessment Tool (SWAT). The estimated sediment accumulation rates by SWAT were compared to estimates relying on radionuclide dating of sediment cores and bathymetric survey methods. Based on the sediment accumulation rate, the remaining reservoir capacity for each study site was estimated. Evaluation of the anthropogenic impacts including land use change and dam construction on the sediment yield were assessed in this research. The regression analysis was done on the current and pre-European settlement sediment yield for the modeled watersheds to predict the current and natural sediment yield in un-modeled watersheds. These eleven watersheds are in the state of Indiana, Michigan, Ohio, New York, and Wisconsin.

  3. Role of lake regulation on glacier-fed rivers in enhancing salmon productivity: the Cook Inlet watershed, south-central Alaska, USA

    Science.gov (United States)

    Dorava, Joseph M.; Milner, Alexander M.

    2000-10-01

    Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation.Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat.

  4. Greenhouse gases concentrations and fluxes from subtropical small reservoirs in relation with watershed urbanization

    Science.gov (United States)

    Wang, Xiaofeng; He, Yixin; Yuan, Xingzhong; Chen, Huai; Peng, Changhui; Yue, Junsheng; Zhang, Qiaoyong; Diao, Yuanbin; Liu, Shuangshuang

    2017-04-01

    Greenhouse gas (GHG) emissions from reservoirs and global urbanization have gained widespread attention, yet the response of GHG emissions to the watershed urbanization is poorly understood. Meanwhile, there are millions of small reservoirs worldwide that receive and accumulate high loads of anthropogenic carbon and nitrogen due to watershed urbanization and can therefore be hotspots of GHG emissions. In this study, we assessed the GHG concentrations and fluxes in sixteen small reservoirs draining urban, agricultural and forested watersheds over a period of one year. The concentrations of pCO2, CH4 and N2O in sampled urban reservoirs that received more sewage input were higher than those in agricultural reservoirs, and were 3, 7 and 10 times higher than those in reservoirs draining in forested areas, respectively. Accordingly, urban reservoirs had the highest estimated GHG flux rate. Regression analysis indicated that dissolved total phosphorus, dissolved organic carbon (DOC) and chlorophyll-a (Chl-a) had great effect on CO2 production, while the nitrogen (N) and phosphorus (P) content of surface water were closely related to CH4 and N2O production. Therefore, these parameters can act as good predictors of GHG emissions in urban watersheds. Given the rapid progress of global urbanization, small urban reservoirs play a crucial role in accounting for regional GHG emissions and cannot be ignored.

  5. Uncertainty based analysis of the impact of watershed phosphorus load on reservoir phosphorus concentration

    Science.gov (United States)

    Karamouz, Mohammad; Taheriyoun, Masoud; Seyedabadi, Mohammadreza; Nazif, Sara

    2015-02-01

    In many regions of the world that depend on surface reservoirs as a source of water supply, eutrophication is a major water quality problem. Developing simulation models to evaluate the impact of watershed nutrient loads on the reservoir's water quality is an essential step in eutrophication management. In this regard, analysis of model uncertainty gives an opportunity to assess the reliability and the margin of safety of the model predictions for Total Maximum Daily Load (TMDL) from the watershed nutrient load. In this study, a computational procedure has been proposed for the analysis of the model uncertainties in simulation of watershed phosphorous load and reservoir phosphorous concentration. Data from the Aharchai watershed which is located upstream of the Satarkhan reservoir in the northwestern part of Iran, is used as the study area to test the effectiveness of the proposed methodology. The Soil and Water Assessment Tools (SWAT) is utilized for assessment of watershed phosphorus load as the main agent resulting in the reservoir eutrophication in the region. The most effective parameters in model performance are identified by a global sensitivity analysis technique named modified Fourier Amplitude Sensitivity Test (FAST) which can incorporate parameter interdependencies. The Generalized Likelihood Uncertainty Estimation (GLUE) technique is also applied to set up behavioral ranges of the parameters that are relevant to the actual observations. Finally, the cumulative weighted-likelihood distribution functions (CWLDF) are derived for outputs of the SWAT. They are used jointly for estimation of results uncertainty limits using the Copula method. To assess the effectiveness of applying Best Management Practices (BMPs) in the watershed, two scenarios of with and without BMPs application are tested. The results showed the effectiveness of the proposed model in uncertainty estimation of watershed phosphorus load and reservoir phosphorus concentration as well as the

  6. Modeling the relationship between landscape characteristics and water quality in a typical highly intensive agricultural small watershed, Dongting lake basin, south central China.

    Science.gov (United States)

    Li, Hongqing; Liu, Liming; Ji, Xiang

    2015-03-01

    Understanding the relationship between landscape characteristics and water quality is critically important for estimating pollution potential and reducing pollution risk. Therefore, this study examines the relationship between landscape characteristics and water quality at both spatial and temporal scales. The study took place in the Jinjing River watershed in 2010; seven landscape types and four water quality pollutions were chosen as analysis parameters. Three different buffer areas along the river were drawn to analyze the relationship as a function of spatial scale. The results of a Pearson's correlation coefficient analysis suggest that "source" landscape, namely, tea gardens, residential areas, and paddy lands, have positive effects on water quality parameters, while forests exhibit a negative influence on water quality parameters because they represent a "sink" landscape and the sub-watershed level is identified as a suitable scale. Using the principal component analysis, tea gardens, residential areas, paddy lands, and forests were identified as the main landscape index. A stepwise multiple regression analysis was employed to model the relationship between landscape characteristics and water quality for each season. The results demonstrate that both landscape composition and configuration affect water quality. In summer and winter, the landscape metrics explained approximately 80.7 % of the variance in the water quality variables, which was higher than that for spring and fall (60.3 %). This study can help environmental managers to understand the relationships between landscapes and water quality and provide landscape ecological approaches for water quality control and land use management.

  7. Fena Valley Reservoir watershed and water-balance model updates and expansion of watershed modeling to southern Guam

    Science.gov (United States)

    Rosa, Sarah N.; Hay, Lauren E.

    2017-12-01

    In 2014, the U.S. Geological Survey, in cooperation with the U.S. Department of Defense’s Strategic Environmental Research and Development Program, initiated a project to evaluate the potential impacts of projected climate-change on Department of Defense installations that rely on Guam’s water resources. A major task of that project was to develop a watershed model of southern Guam and a water-balance model for the Fena Valley Reservoir. The southern Guam watershed model provides a physically based tool to estimate surface-water availability in southern Guam. The U.S. Geological Survey’s Precipitation Runoff Modeling System, PRMS-IV, was used to construct the watershed model. The PRMS-IV code simulates different parts of the hydrologic cycle based on a set of user-defined modules. The southern Guam watershed model was constructed by updating a watershed model for the Fena Valley watersheds, and expanding the modeled area to include all of southern Guam. The Fena Valley watershed model was combined with a previously developed, but recently updated and recalibrated Fena Valley Reservoir water-balance model.Two important surface-water resources for the U.S. Navy and the citizens of Guam were modeled in this study; the extended model now includes the Ugum River watershed and improves upon the previous model of the Fena Valley watersheds. Surface water from the Ugum River watershed is diverted and treated for drinking water, and the Fena Valley watersheds feed the largest surface-water reservoir on Guam. The southern Guam watershed model performed “very good,” according to the criteria of Moriasi and others (2007), in the Ugum River watershed above Talofofo Falls with monthly Nash-Sutcliffe efficiency statistic values of 0.97 for the calibration period and 0.93 for the verification period (a value of 1.0 represents perfect model fit). In the Fena Valley watershed, monthly simulated streamflow volumes from the watershed model compared reasonably well with the

  8. Concentrations and loads of nutrients in the tributaries of the Lake Okeechobee watershed, south-central Florida, water years 2004-2008

    Science.gov (United States)

    Byrne, Michael J.; Wood, Molly S.

    2011-01-01

    Lake Okeechobee in south-central Florida is the second largest freshwater lake in the contiguous United States. Excessive phosphorus loading, harmful high and low water levels, and rapid expansion of non-native vegetation have threatened the health of the lake in recent decades. A study was conducted to monitor discharge and nutrient concentrations from selected tributaries into Lake Okeechobee and to evaluate nutrient loads. The data analysis was performed at 16 monitoring stations from December 2003 to September 2008. Annual and seasonal discharge measured at monitoring stations is affected by rainfall. Hurricanes affected three wet years (2004, 2005, and the latter part of 2008) and resulted in substantially greater discharge than the drought years of 2006, 2007, and the early part of 2008. Rainfall supplies about 50 percent of the water to Lake Okeechobee, discharge from the Kissimmee River supplies about 25 percent, and discharge from tributaries and groundwater seepage along the lake perimeter collectively provide the remaining 25 percent. Annually, tributary discharge from basins located on the west side of the Kissimmee River is about 5 to 6 times greater than that from basins located on the east side. For the purposes of this study, the basins on the east side of the Kissimmee River are called "priority basins" because of elevated phosphorus concentrations, while those on the west side are called "nonpriority" basins. Total annual discharge in the non-priority basins ranged from 245,000 acre-feet (acre-ft) in 2007 to 1,322,000 acre-ft in 2005, while annual discharge from the priority basins ranged from 41,000 acre-ft in 2007 to 219,000 acre-ft in 2005. Mean total phosphorus concentrations ranged from 0.10 to 0.54 milligrams per liter (mg/L) at the 16 tributaries during 2004–2008. Mean concentrations were significantly higher at priority basin sites than at non-priority basin sites, particularly at Arbuckle Creek and C 41A Canal. Concentrations of organic

  9. Influence Assessment of Multiple Large-sized Reservoirs on Flooding in the Huai River Watershed, China

    Science.gov (United States)

    Wan, X. Y.

    2017-12-01

    The extensive constructions of reservoirs change the hydrologic characteristics of the associated watersheds, which obviously increases the complexity of watershed flood control decisions. By evaluating the impacts of the multi-reservoir system on the flood hydrograph, it becomes possible to improve the effectiveness of the flood control decisions. In this paper we compare the non-reservoir flood hydrograph with the actual observed flood hydrograph using the Lutaizi upstream of Huai river in East China as a representative case, where 20 large-scale/large-sized reservoirs have been built. Based on the total impact of the multi-reservoir system, a novel strategy, namely reservoir successively added (RSA) method, is presented to evaluate the contribution of each reservoir to the total impact. According each reservoir contribution, the "highly effective" reservoirs for watershed flood control are identified via hierarchical clustering. Moreover, we estimate further the degree of impact of the reservoir current operation rules on the flood hydrograph on the base of the impact of dams themselves. As a result, we find that the RSA method provides a useful method for analysis of multi-reservoir systems by partitioning the contribution of each reservoir to the total impacts on the flooding at the downstream section. For all the historical large floods examined, the multi-reservoir system in the Huai river watershed has a significant impact on flooding at the downstream Lutaizi section, on average reducing the flood volume and peak discharge by 13.92 × 108 m3 and 18.7% respectively. It is more informative to evaluate the maximum impact of each reservoir (on flooding at the downstream section) than to examine the average impact. Each reservoir has a different impact on the flood hydrograph at the Lutaizi section. In particular, the Meishan, Xianghongdian, Suyahu, Nanwan, Nianyushan and Foziling reservoirs exert a strong influence on the flood hydrograph, and are therefore

  10. From eutrophic to mesotrophic: modelling watershed management scenarios to change the trophic status of a reservoir.

    Science.gov (United States)

    Mateus, Marcos; Almeida, Carina; Brito, David; Neves, Ramiro

    2014-03-12

    Management decisions related with water quality in lakes and reservoirs require a combined land-water processes study approach. This study reports on an integrated watershed-reservoir modeling methodology: the Soil and Water Assessment Tool (SWAT) model to estimate the nutrient input loads from the watershed, used afterwards as boundary conditions to the reservoir model, CE-QUAL-W2. The integrated modeling system was applied to the Torrão reservoir and drainage basin. The objective of the study was to quantify the total maximum input load that allows the reservoir to be classified as mesotrophic. Torrão reservoir is located in the Tâmega River, one of the most important tributaries of the Douro River in Portugal. The watershed is characterized by a variety of land uses and urban areas, accounting for a total Waste Water Treatment Plants (WWTP) discharge of ~100,000 p.e. According to the criteria defined by the National Water Institute (based on the WWTP Directive), the Torrão reservoir is classified as eutrophic. Model estimates show that a 10% reduction in nutrient loads will suffice to change the state to mesotrophic, and should target primarily WWTP effluents, but also act on diffuse sources. The method applied in this study should provide a basis for water environmental management decision-making.

  11. Assessment of conservation practices in the Fort Cobb Reservoir watershed, southwestern Oklahoma

    Science.gov (United States)

    Becker, Carol J.

    2011-01-01

    The Fort Cobb Reservoir watershed encompasses about 813 square kilometers of rural farm land in Caddo, Custer, and Washita Counties in southwestern Oklahoma. The Fort Cobb Reservoir and six stream segments were identified on the Oklahoma 1998 303(d) list as not supporting designated beneficial uses because of impairment by nutrients, suspended solids, sedimentation, pesticides, and unknown toxicity. As a result, State and Federal agencies, in collaboration with conservation districts and landowners, started conservation efforts in 2001 to decrease erosion and transport of sediments and nutrients to the reservoir and improve water quality in tributaries. The U.S. Department of Agriculture selected the Fort Cobb Reservoir watershed in 2003 as 1 of 14 benchmark watersheds under the Conservation Effectiveness Assessment Project with the objective of quantifying the environmental benefits derived from agricultural conservation programs in reducing inflows of sediments and phosphorus to the reservoir. In November 2004, the Biologic, Geographic, Geologic, and Water Disciplines of the U.S. Geological Survey, in collaboration with the Agricultural Research Service, Grazinglands Research Laboratory in El Reno, Oklahoma, began an interdisciplinary investigation to produce an integrated publication to complement this program. This publication is a compilation of 10 report chapters describing land uses, soils, geology, climate, and water quality in streams and the reservoir through results of field and remote sensing investigations from 2004 to 2007. The investigations indicated that targeting best-management practices to small intermittent streams draining to the reservoir and to the Cobb Creek subwatershed may effectively augment efforts to improve eutrophic to hypereutrophic conditions that continue to affect the reservoir. The three major streams flowing into the reservoir contribute nutrients causing eutrophication, but minor streams draining cultivated fields near the

  12. The modified SWAT model for predicting fecal coliform in the Wachusett Reservoir Watershed, USA

    Science.gov (United States)

    Fecal contamination has been an issue for water quality because fecal coliform bacteria are used as an indicator organism to detect pathogens in water. In order to assess fecal contamination in the Wachusett Reservoir Watershed in Massachusetts, USA, the Soil and Water Assessment Tool (SWAT), a comm...

  13. Controlling Highway Runoff Pollution In Drinking Water Supply Reservoir Watersheds

    Science.gov (United States)

    1999-10-01

    This study evaluated the effectiveness of an innovative stormwater best management practice in treating highway runoff and protecting the integrity of the drinking water reservoir in Warrenton, Virginia. The research focused on the use of a biodetent...

  14. Multi-objective game-theory models for conflict analysis in reservoir watershed management.

    Science.gov (United States)

    Lee, Chih-Sheng

    2012-05-01

    This study focuses on the development of a multi-objective game-theory model (MOGM) for balancing economic and environmental concerns in reservoir watershed management and for assistance in decision. Game theory is used as an alternative tool for analyzing strategic interaction between economic development (land use and development) and environmental protection (water-quality protection and eutrophication control). Geographic information system is used to concisely illustrate and calculate the areas of various land use types. The MOGM methodology is illustrated in a case study of multi-objective watershed management in the Tseng-Wen reservoir, Taiwan. The innovation and advantages of MOGM can be seen in the results, which balance economic and environmental concerns in watershed management and which can be interpreted easily by decision makers. For comparison, the decision-making process using conventional multi-objective method to produce many alternatives was found to be more difficult. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. The modified SWAT model for predicting fecal coliforms in the Wachusett Reservoir Watershed, USA.

    Science.gov (United States)

    Cho, Kyung Hwa; Pachepsky, Yakov A; Kim, Joon Ha; Kim, Jung-Woo; Park, Mi-Hyun

    2012-10-01

    This study assessed fecal coliform contamination in the Wachusett Reservoir Watershed in Massachusetts, USA using Soil and Water Assessment Tool (SWAT) because bacteria are one of the major water quality parameters of concern. The bacteria subroutine in SWAT, considering in-stream bacteria die-off only, was modified in this study to include solar radiation-associated die-off and the contribution of wildlife. The result of sensitivity analysis demonstrates that solar radiation is one of the most significant fate factors of fecal coliform. A water temperature-associated function to represent the contribution of beaver activity in the watershed to fecal contamination improved prediction accuracy. The modified SWAT model provides an improved estimate of bacteria from the watershed. Our approach will be useful for simulating bacterial concentrations to provide predictive and reliable information of fecal contamination thus facilitating the implementation of effective watershed management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. [Coupling SWAT and CE-QUAL-W2 models to simulate water quantity and quality in Shanmei Reservoir watershed].

    Science.gov (United States)

    Liu, Mei-Bing; Chen, Dong-Ping; Chen, Xing-Wei; Chen, Ying

    2013-12-01

    A coupled watershed-reservoir modeling approach consisting of a watershed distributed model (SWAT) and a two-dimensional laterally averaged model (CE-QUAL-W2) was adopted for simulating the impact of non-point source pollution from upland watershed on water quality of Shanmei Reservoir. Using the daily serial output from Shanmei Reservoir watershed by SWAT as the input to Shanmei Reservoir by CE-QUAL-W2, the coupled modeling was calibrated for runoff and outputs of sediment and pollutant at watershed scale and for elevation, temperature, nitrate, ammonium and total nitrogen in Shanmei Reservoir. The results indicated that the simulated values agreed fairly well with the observed data, although the calculation precision of downstream model would be affected by the accumulative errors generated from the simulation of upland model. The SWAT and CE-QUAL-W2 coupled modeling could be used to assess the hydrodynamic and water quality process in complex watershed comprised of upland watershed and downstream reservoir, and might further provide scientific basis for positioning key pollution source area and controlling the reservoir eutrophication.

  17. A systematic assessment of watershed-scale nonpoint source pollution during rainfall-runoff events in the Miyun Reservoir watershed.

    Science.gov (United States)

    Qiu, Jiali; Shen, Zhenyao; Wei, Guoyuan; Wang, Guobo; Xie, Hui; Lv, Guanping

    2018-03-01

    The assessment of peak flow rate, total runoff volume, and pollutant loads during rainfall process are very important for the watershed management and the ecological restoration of aquatic environment. Real-time measurements of rainfall-runoff and pollutant loads are always the most reliable approach but are difficult to carry out at all desired location in the watersheds considering the large consumption of material and financial resources. An integrated environmental modeling approach for the estimation of flash streamflow that combines the various hydrological and quality processes during rainstorms within the agricultural watersheds is essential to develop targeted management strategies for the endangered drinking water. This study applied the Hydrological Simulation Program-Fortran (HSPF) to simulate the spatial and temporal variation in hydrological processes and pollutant transport processes during rainstorm events in the Miyun Reservoir watershed, a drinking water resource area in Beijing. The model performance indicators ensured the acceptable applicability of the HSPF model to simulate flow and pollutant loads in the studied watershed and to establish a relationship between land use and the parameter values. The proportion of soil and land use was then identified as the influencing factors of the pollution intensities. The results indicated that the flush concentrations were much higher than those observed during normal flow periods and considerably exceeded the limits of Class III Environmental Quality Standards for Surface Water (GB3838-2002) for the secondary protection zones of the drinking water resource in China. Agricultural land and leached cinnamon soils were identified as the key sources of sediment, nutrients, and fecal coliforms. Precipitation volume was identified as a driving factor that determined the amount of runoff and pollutant loads during rainfall processes. These results are useful to improve the streamflow predictions, provide

  18. New Approach for Evaluation of a Watershed Ecosystem Service for Avoiding Reservoir Sedimentation and Its Economic Value: A Case Study from Ertan Reservoir in Yalong River, China

    Directory of Open Access Journals (Sweden)

    Bilige Sude

    2011-01-01

    Full Text Available A model was established to simulate an ecosystem service of avoiding reservoir sedimentation and its economic value based on the process of sediment delivery in a watershed. The model included fabricating the watershed of the study reservoir. The sediment retention coefficient of different land cover types were used to simulate the spatial patterns of the annual quantity of the sediment that were prevented from entering the reservoir by the vegetation in each cell followed the flow path in watershed. The economic value of the ecosystem service in this model was determined by the marginal cost of reservoir desilting. This study took the Ertan reservoir as an example. The results showed that most eroded soil was intercepted by different types of ecosystems in the process of sediment delivery in a watershed. The region with a higher quantity of sediment retention was around the reservoir. The absolute quantity of average sediment retention in forestland was lower, so the sediment retention ability of forestland failed to be brought into fullest play in watershed.

  19. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    Directory of Open Access Journals (Sweden)

    Renzhi Liu

    2015-12-01

    Full Text Available Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA, designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River. Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  20. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    Science.gov (United States)

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-01-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  1. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    Science.gov (United States)

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-02

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  2. Reconstructing Watershed History from Reservoir Stratigraphy: Englebright Lake, Yuba River, Northern California

    Science.gov (United States)

    Snyder, N. P.; Alpers, C. N.; Childs, J. R.; Curtis, J. A.; Flint, L. E.; Holmes, C. W.; Rubin, D. M.; Wright, S. A.

    2004-12-01

    Reservoirs provide the opportunity to study fluvial processes and rates in a controlled setting because they are effective traps of sediment and are often well monitored. An extensive sediment coring and sampling campaign was done in Englebright Lake on the Yuba River in northern California as part of a fish-habitat restoration study. The Yuba watershed (particularly the southern part) was the site of intensive hydraulic gold mining in the 19th and early 20th century, and Englebright Dam was built in 1940 to trap mining debris. Results of a bathymetric survey in 2001 indicate that the reservoir was 26% full (22x106 m3 of material). The physical properties of the entire deposit were extrapolated from ˜300 m of cores collected at 7 sites along the longitudinal axis of the reservoir in 2002. The mass of the deposit is 26x106 metric tons, of which 3.2% is organic. The sediment is ˜65% sand and gravel, and distinct layers of differing grain size (sand-gravel, silt-clay, organics) are well preserved in the cores. The depositional chronology of the reservoir was established using 137Cs analysis and the relations between the cored stratigraphy and the hydrologic and impoundment history of the watershed. Deposits from three major flood events (1955, 1964, 1997; each with discharge >3,400 m3/s) were identified in the stratigraphy of most of the coring sites. Observations of recent (post-1997) depositional patterns are guiding the development of a conceptual model of reservoir-sedimentation processes during floods, drawdowns, and intraflood periods. Enlargement of an upstream dam on the North Yuba River in 1970 caused a decrease in flood frequency in the Yuba River and changed management of Englebright Lake (ending annual drawdowns). A relict topset-foreset-bottomset sequence observed in the cored stratigraphy is interpreted to correlate with this change in watershed management; a second deltaic sequence was deposited on top of the first after 1970. Post-1970 average annual

  3. Influence of watershed activities on the water quality and fish assemblages of a tropical African reservoir.

    Science.gov (United States)

    Mustapha, Moshood K

    2009-09-01

    Agricultural and fisheries activities around the watershed of an African tropical reservoir (Oyun reservoir, Offa, Nigeria) were found to contribute significantly to water quality deterioration of the dam axis of the reservoir, leading to eutrophication of that part of the reservoir. This is evident from the high amount of nitrate (6.4 mg/l), phosphate (2.2 mg/l) and sulphate (16.9 mg/l) in the water body which was higher than most other reservoirs in Nigeria. These nutrients originate in fertilizer run-offs from nearby farmlands and were found in higher concentrations in the rainy season which is usually the peak of agricultural activities in the locality. The eutrophication was more pronounced on the dam axis because it is the point of greatest human contact where pressure and run-off of sediments were high. The eutrophication altered the food web cycle which consequently affected the fish species composition and abundance with the dominance of cichlids (planktivorous group) and decline of some species in the fish population. Best management practices (BMP) to control and reduce the eutrophication and improve water quality and fish assemblages should be adopted and adapted to suit the situation in the reservoir.

  4. Optimal Reoperation of Multi-Reservoirs for Integrated Watershed Management with Multiple Benefits

    Directory of Open Access Journals (Sweden)

    Xinyi Xu

    2014-04-01

    Full Text Available Constructing reservoirs can make more efficient use of water resources for human society. However, the negative impacts of these projects on the environment are often ignored. Optimal reoperation of reservoirs, which considers not only in socio-economic values but also environmental benefits, is increasingly important. A model of optimal reoperation of multi-reservoirs for integrated watershed management with multiple benefits was proposed to alleviate the conflict between water use and environmental deterioration. The social, economic, water quality and ecological benefits were respectively taken into account as the scheduling objectives and quantified according to economic models. River minimum ecological flows and reservoir water levels based on flood control were taken as key constraint conditions. Feasible search discrete differential dynamic programming (FS-DDDP was used to run the model. The proposed model was used in the upstream of the Nanpan River, to quantitatively evaluate the difference between optimal reoperation and routine operation. The results indicated that the reoperation could significantly increase the water quality benefit and have a minor effect on the benefits of power generation and irrigation under different hydrological years. The model can be readily adapted to other multi-reservoir systems for water resources management.

  5. Hybrid Multi-Objective Optimization of Folsom Reservoir Operation to Maximize Storage in Whole Watershed

    Science.gov (United States)

    Goharian, E.; Gailey, R.; Maples, S.; Azizipour, M.; Sandoval Solis, S.; Fogg, G. E.

    2017-12-01

    The drought incidents and growing water scarcity in California have a profound effect on human, agricultural, and environmental water needs. California experienced multi-year droughts, which have caused groundwater overdraft and dropping groundwater levels, and dwindling of major reservoirs. These concerns call for a stringent evaluation of future water resources sustainability and security in the state. To answer to this call, Sustainable Groundwater Management Act (SGMA) was passed in 2014 to promise a sustainable groundwater management in California by 2042. SGMA refers to managed aquifer recharge (MAR) as a key management option, especially in areas with high variation in water availability intra- and inter-annually, to secure the refill of underground water storage and return of groundwater quality to a desirable condition. The hybrid optimization of an integrated water resources system provides an opportunity to adapt surface reservoir operations for enhancement in groundwater recharge. Here, to re-operate Folsom Reservoir, objectives are maximizing the storage in the whole American-Cosumnes watershed and maximizing hydropower generation from Folsom Reservoir. While a linear programing (LP) module tends to maximize the total groundwater recharge by distributing and spreading water over suitable lands in basin, a genetic based algorithm, Non-dominated Sorting Genetic Algorithm II (NSGA-II), layer above it controls releases from the reservoir to secure the hydropower generation, carry-over storage in reservoir, available water for replenishment, and downstream water requirements. The preliminary results show additional releases from the reservoir for groundwater recharge during high flow seasons. Moreover, tradeoffs between the objectives describe that new operation performs satisfactorily to increase the storage in the basin, with nonsignificant effects on other objectives.

  6. Estimates of Nitrogen Removal in U.S. Streams and Reservoirs from the SPARROW Watershed Model

    Science.gov (United States)

    Alexander, R. B.; Smith, R. A.; Schwarz, G. E.; Nolan, J. V.; Boyer, E. W.

    2003-12-01

    Greater understanding is needed of the biotic and abiotic processes that remove nitrogen (N) from streams and reservoirs to quantify transport to downstream coastal waters where eutrophication is a major concern. Recent studies have improved estimates of N removal rates (e.g., denitrification, biological uptake) over small spatial scales in low-order streams. However, limited knowledge of the factors that explain the large variation in literature removal rates has made it difficult to accurately predict N transport through the range of stream and reservoir sizes that link sources to downstream waters. Spatially referenced watershed models (SPARROW) have been used to statistically estimate long-term mean-annual rates of total nitrogen removal in streams and reservoirs over large spatial scales. These rates are estimated as a function of physical and hydraulic properties (channel depth, water travel time) that influence the contact and exchange of water with benthic sediment. We recently refined our SPARROW model structure with expanded descriptions of climatic, topographic, and other surficial features of terrestrial and aquatic landscapes. We find that the net rates of N removal decline from about 0.3 day-1 of water travel time in streams with depths less than 0.5 meters to negligible quantities in large rivers (greater than 4 meters). These rates are generally consistent with those of earlier regional and national SPARROW models and with measured rates from the literature (adjusted for water travel time) over the reported range of stream depths. A settling velocity of approximately 8 meters year-1 is estimated for lakes and reservoirs and agrees well with literature rates for lakes where denitrification is the predominant removal process. We applied these removal rates within the SPARROW stream and reservoir network to estimate the regional-scale N transport and delivery to U.S. coastal waters.

  7. [Aquatic insects and water quality in Peñas Blancas watershed and reservoir].

    Science.gov (United States)

    Mora, Meyer Guevara

    2011-06-01

    The aquatic insects have been used to evaluate water quality of aquatic environments. The population of aquatic insects and the water quality of the area were characterized according to the natural and human alterations present in the study site. During the monthly-survey, pH, DO, temperature, water level, DBO, PO4 and NO3 were measured. Biological indexes (abundance, species richness and the BMWP-CR) were used to evaluate the water quality. No relation between environmental and aquatic insects was detected. Temporal and spatial differences attributed to the flow events (temporal) and the presence of Peñas Blancas reservoir (spatial). In the future, the investigations in Peñas Blancas watershed need to be focused on determining the real influence of the flows, sediment release and the possible water quality degradation because of agriculture activities.

  8. Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

    Directory of Open Access Journals (Sweden)

    M. Wang

    2015-05-01

    Full Text Available The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN and total phosphorus (TP. The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

  9. Influence of watershed activities on the water quality and fish assemblages of a tropical African reservoir

    Directory of Open Access Journals (Sweden)

    Moshood K Mustapha

    2009-09-01

    Full Text Available Agricultural and fisheries activities around the watershed of an African tropical reservoir (Oyun reservoir, Offa, Nigeria were found to contribute significantly to water quality deterioration of the dam axis of the reservoir, leading to eutrophication of that part of the reservoir. This is evident from the high amount of nitrate (6.4 mg/l, phosphate (2.2 mg/l and sulphate (16.9 mg/l in the water body which was higher than most other reservoirs in Nigeria. These nutrients originate in fertilizer run-offs from nearby farmlands and were found in higher concentrations in the rainy season which is usually the peak of agricultural activities in the locality. The eutrophication was more pronounced on the dam axis because it is the point of greatest human contact where pressure and run-off of sediments were high. The eutrophication altered the food web cycle which consequently affected the fish species composition and abundance with the dominance of cichlids (planktivorous group and decline of some species in the fish population. Best management practices (BMP to control and reduce the eutrophication and improve water quality and fish assemblages should be adopted and adapted to suit the situation in the reservoir. Rev. Biol. Trop. 57 (3: 707-719. Epub 2009 September 30.Las actividades agrícolas y pesqueras que se desarrollan alrededor del embalse tropical africano de Oyun, Offa, Nigeria, contribuyen de forma significativa al deterioro de la calidad del agua, provocando eutroficación. Esto es evidente a partir de la gran cantidad de nitrato (6.4 mg / l, fosfato (2.2 mg / l y sulfato (16.9 mg / l, si se compara con otros embalses de Nigeria. Estos nutrientes proceden de fertilizantes utilizados en áreas agrícolas y las concentraciones aumentan en la estación lluviosa cuando aumentan las actividades agrícolas en la zona. La eutroficación es más pronunciada donde existe mayor actividad humana, y altera la cadena trófica y en consecuencia, la

  10. Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir.

    Science.gov (United States)

    Üçler, N; Engin, G Onkal; Köçken, H G; Öncel, M S

    2015-05-01

    In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.

  11. Prediction of Reservoir Sediment Quality Based on Erosion Processes in Watershed Using Mathematical Modelling

    Directory of Open Access Journals (Sweden)

    Natalia Junakova

    2017-12-01

    Full Text Available Soil erosion, as a significant contributor to nonpoint-source pollution, is ranked top of sediment sources, pollutants attached to sediment, and pollutants in the solution in surface water. This paper is focused on the design of mathematical model intended to predict the total content of nitrogen (N, phosphorus (P, and potassium (K in bottom sediments in small water reservoirs depending on water erosion processes, together with its application and validation in small agricultural watershed of the Tisovec River, Slovakia. The designed model takes into account the calculation of total N, P, and K content adsorbed on detached and transported soil particles, which consists of supplementing the soil loss calculation with a determination of the average nutrient content in topsoils. The dissolved forms of these elements are neglected in this model. Validation of the model was carried out by statistical assessment of calculated concentrations and measured concentrations in Kľušov, a small water reservoir (Slovakia, using the t-test and F-test, at a 0.05 significance level. Calculated concentrations of total N, P, and K in reservoir sediments were in the range from 0.188 to 0.236 for total N, from 0.065 to 0.078 for total P, and from 1.94 to 2.47 for total K. Measured nutrient concentrations in composite sediment samples ranged from 0.16 to 0.26% for total N, from 0.049 to 0.113% for total P, and from 1.71 to 2.42% for total K. The statistical assessment indicates the applicability of the model in predicting the reservoir’s sediment quality detached through erosion processes in the catchment.

  12. Evaluation of mercury cycling and hypolimnetic oxygenation in mercury-impacted seasonally stratified reservoirs in the Guadalupe River watershed, California

    Science.gov (United States)

    McCord, Stephen A.; Beutel, Marc W.; Dent, Stephen R.; Schladow, S. G.

    2016-10-01

    Surface water reservoirs trap inorganic mercury delivered from their watersheds, create conditions that convert inorganic mercury to highly toxic methylmercury (MeHg), and host sportfish in which MeHg bioaccumulates. The Santa Clara Valley Water District (District) actively manages and monitors four mercury-impaired reservoirs that help to serve communities in South San Francisco Bay, California. The Guadalupe River watershed, which contains three of those reservoirs, also includes the New Almaden mercury-mining district, the largest historic mercury producer in North America. Monthly vertical profiles of field measurements and grab samples in years 2011-2013 portray annual cycling of density stratification, dissolved oxygen (DO), and MeHg. Monitoring results highlight the role that hypolimnetic hypoxia plays in MeHg distribution in the water column, as well as the consistent, tight coupling between MeHg in ecological compartments (water, zooplankton, and bass) across the four reservoirs. Following the 2011-2013 monitoring period, the District designed and installed hypolimnetic oxygenation systems (HOS) in the four reservoirs in an effort to repress MeHg buildup in bottom waters and attain regulatory targets for MeHg in water and fish tissue. Initial HOS operation in Calero Reservoir in 2014 enhanced bottom water DO and depressed hypolimnetic buildup of MeHg, but did not substantially decrease mercury levels in zooplankton or small fish.

  13. Soil erosion and sediment fluxes analysis: a watershed study of the Ni Reservoir, Spotsylvania County, VA, USA.

    Science.gov (United States)

    Pope, Ian C; Odhiambo, Ben K

    2014-03-01

    Anthropogenic forces that alter the physical landscape are known to cause significant soil erosion, which has negative impact on surface water bodies, such as rivers, lakes/reservoirs, and coastal zones, and thus sediment control has become one of the central aspects of catchment management planning. The revised universal soil loss equation empirical model, erosion pins, and isotopic sediment core analyses were used to evaluate watershed erosion, stream bank erosion, and reservoir sediment accumulation rates for Ni Reservoir, in central Virginia. Land-use and land cover seems to be dominant control in watershed soil erosion, with barren land and human-disturbed areas contributing the most sediment, and forest and herbaceous areas contributing the least. Results show a 7 % increase in human development from 2001 (14 %) to 2009 (21.6 %), corresponding to an increase in soil loss of 0.82 Mg ha(-1) year(-1) in the same time period. (210)Pb-based sediment accumulation rates at three locations in Ni Reservoir were 1.020, 0.364, and 0.543 g cm(-2) year(-1) respectively, indicating that sediment accumulation and distribution in the reservoir is influenced by reservoir configuration and significant contributions from bedload. All three locations indicate an increase in modern sediment accumulation rates. Erosion pin results show variability in stream bank erosion with values ranging from 4.7 to 11.3 cm year(-1). These results indicate that urban growth and the decline in vegetative cover has increased sediment fluxes from the watershed and poses a significant threat to the long-term sustainability of the Ni Reservoir as urbanization continues to increase.

  14. Hydrography - HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS: Lakes, Ponds, Reservoirs, Swamps, and Marshes in Watersheds of Indiana (U. S. Geological Survey, 1:24,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS.SHP is a polygon shapefile that contains features of lakes, ponds, reservoirs, swamps and marshes in watersheds in and...

  15. Application of SWAT-HS, a lumped hillslope model to simulate hydrology in the Cannonsville Reservoir watershed, New York

    Science.gov (United States)

    Hoang, Linh; Schneiderman, Elliot; Mukundan, Rajith; Moore, Karen; Owens, Emmet; Steenhuis, Tammo

    2017-04-01

    Surface runoff is the primary mechanism transporting substances such as sediments, agricultural chemicals, and pathogens to receiving waters. In order to predict runoff and pollutant fluxes, and to evaluate management practices, it is essential to accurately predict the areas generating surface runoff, which depend on the type of runoff: infiltration-excess runoff and saturation-excess runoff. The watershed of Cannonsville reservoir is part of the New York City water supply system that provides high quality drinking water to nine million people in New York City (NYC) and nearby communities. Previous research identified saturation-excess runoff as the dominant runoff mechanism in this region. The Soil and Water Assessment Tool (SWAT) is a promising tool to simulate the NYC watershed given its broad application and good performance in many watersheds with different scales worldwide, for its ability to model water quality responses, and to evaluate the effect of management practices on water quality at the watershed scale. However, SWAT predicts runoff based mainly on soil and land use characteristics, and implicitly considers only infiltration-excess runoff. Therefore, we developed a modified version of SWAT, referred to as SWAT-Hillslope (SWAT-HS), which explicitly simulates saturation-excess runoff by redefining Hydrological Response Units (HRUs) based on wetness classes with varying soil water storage capacities, and by introducing a surface aquifer with the ability to route interflow from "drier" to "wetter" wetness classes. SWAT-HS was first tested at Town Brook, a 37 km2 headwater watershed draining to the Cannonsville reservoir using a single sub-basin for the whole watershed. SWAT-HS performed well, and predicted streamflow yielded Nash-Sutcliffe Efficiencies of 0.68 and 0.87 at the daily and monthly time steps, respectively. More importantly, it predicted the spatial distribution of saturated areas accurately. Based on the good performance in the Town Brook

  16. Classification of the Relationship between Household Welfare and Ecosystem Reliance in the Miyun Reservoir Watershed, China

    Directory of Open Access Journals (Sweden)

    Fengchun Wang

    2017-12-01

    Full Text Available Household welfare is inseparable from the environment because of its dependence on ecosystems and their services. However, linking household welfare and ecosystems in order to inform differentiated household livelihood development in spatially heterogeneous regions is still a great challenge. Based on a field survey of 1754 households, we grouped the relationships between household welfare (defined by total income and ecosystem reliance (expressed by an index of dependence on ecosystem services in the Watershed of Miyun Reservoir, the only source of surface water for domestic use in Beijing, China. The relationships can be grouped into four types: high welfare and high dependency; low welfare and low dependency; high welfare and low dependence; and low welfare and high dependency. Family structure, households’ education and skill level, and the proximity to Beijing have significant impacts on household welfare, while the quantity of natural capital and eco-compensation fund significantly contribute to the ecosystem dependence. Maintaining suitable family size and age structure, improving education and skill levels, and strengthening payment for ecosystem services within low welfare households would be effective approaches to their welfare improvement. The above classification can help design tailored policy and management options to promote sustainable livelihoods based on different household subgroups.

  17. Geology and mineral resources of the Southwestern and South-Central Wyoming Sagebrush Focal Area, Wyoming, and the Bear River Watershed Sagebrush Focal Area, Wyoming and Utah: Chapter E in Mineral resources of the Sagebrush Focal Areas of Idaho, Montana, Nevada, Oregon, Utah, and Wyoming

    Science.gov (United States)

    Wilson, Anna B.; Hayes, Timothy S.; Benson, Mary Ellen; Yager, Douglas B.; Anderson, Eric D.; Bleiwas, Donald I.; DeAngelo, Jacob; Dicken, Connie L.; Drake, Ronald M.; Fernette, Gregory L.; Giles, Stuart A.; Glen, Jonathan M. G.; Haacke, Jon E.; Horton, John D.; Parks, Heather L.; Rockwell, Barnaby W.; Williams, Colin F.

    2016-10-04

    SummaryThe U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A). The purpose of the proposed action is to protect the greater sage-grouse (Centrocercus urophasianus) and its habitat from potential adverse effects of locatable mineral exploration and mining. The U.S. Geological Survey Sagebrush Mineral-Resource Assessment (SaMiRA) project was initiated in November 2015 and supported by the Bureau of Land Management to (1) assess locatable mineral-resource potential and (2) to describe leasable and salable mineral resources for the seven SFAs and Nevada additions.This chapter summarizes the current status of locatable, leasable, and salable mineral commodities and assesses the potential of locatable minerals in the Southwestern and South-Central Wyoming and Bear River Watershed, Wyoming and Utah, SFAs.

  18. Hydrological Response Unit Analysis Using AVSWAT 2000 for Keuliling Reservoir Watershed, Aceh Province, Indonesia

    Directory of Open Access Journals (Sweden)

    . Azmeri

    2015-04-01

    Full Text Available Sediments deposition derived from the erosion in upstream areas can lead to river siltation or canals downstream irrigation. According to the complexity of erosion problem at Keuliling reservoir, it is essential that topography, hydrology, soil type and land use to be analyzed comprehensively. Software used to analyze is AVSWAT 2000 (Arc View Soil and Water Assessment Tools-2000, one of the additional tool of ArcView program. The results obtained are the watershed delineation map, soil type map to produce soil erodibility factor (K which indicates the resistance of soil particles toward exfoliation, land use map to produce crop management factor (C and soil conservation and its management factors (P. Hydrology analysis includes soil type, land use and utility for the erosion rate analysis through Hydrologic Response Unit (HRU. The biggest HRU value of sub-basin is on area 5 and the lowest one is on area 10. All four HRU in sub-basin area 5 are potentially donating high value for HRU. In short, this area has the longest slope length so that it has a large LS factor. About 50% of the land was covered by bushes which gain higher C factor rather than forest. Moreover, it has contour crop conservation technique with 9-20 % declivity resulting in having dominant factor of P. Soil type is dominated by Meucampli Formation which has soil erodibility factor with high level of vulnerable toward the rainfall kinetic energy. All in all, the vast majority of HRU parameters in this sub-basin area obtain the highest HRU value. Hydrology analysis, soil type, and use-land are useful for land area analysis that is susceptible to erosion which was identified through Hydrologic Response Unit (HRU using GIS. As the matter of fact, spatially studies constructed with GIS can facilitate the agency to determine critical areas which are needed to be aware or fully rehabilitated.

  19. Biogeochemical characterization of the Cointzio reservoir (Morelia, Mexico) and identification of a watershed-dependent cycling of nutrients

    Science.gov (United States)

    Némery, J.; Alvarado, R.; Gratiot, N.; Duvert, C.; Mahé, F.; Duwig, C.; Bonnet, M.; Prat, C.; Esteves, M.

    2009-12-01

    The Cointzio reservoir (capacity 70 Mm3) is an essential component of the drinking water supply (20 %) of Morelia city (1 M inhabitants, Michoacán, Mexico). The watershed is 627 km2 and mainly forested (45 %) and cultivated (43 %) with recent increase of avocados plantations. The mean population density is 65 inh./km2 and there are no waste water treatment plants in the villages leading locally to high levels of organic and nutritive pollution. Soils are mostly volcanic and recent deforestations have led to important processes of erosion especially during the wet season (from June to October). As a result the reservoir presents a high turbidity level (Secchi Del Agua (CNA). The water residence time in the reservoir is lower than one year. Nutrients fluxes entering and exiting the reservoir were calculated as the product of water discharges and weekly concentrations of nutrients. Within the reservoir, the vertical distributions of temperature, oxygen, turbidity, pH (with a Hydrolab probe), nutrients (PO43-, NH4+, NO3-), Dissolved Organic Carbon, chlorophyll a (laboratory analysis with a Hach Lange spectrophotometer), phytoplankton and zooplankton (variety and abundance) were measured every month to determine its seasonal dynamics. Samples of deposited sediments were also taken to assess phosphorus (P) stock. Nutrient inputs revealed to be strongly conditioned by the watershed hydrology. During low flow period (November to May), the baseflow is much more concentrated in dissolved nutrients. On the contrary, the high flows (June to October) bring a high amount of suspended sediments (up to 50g/L) that transport nutrients such as particulate P. Despite the high turbidity level of the reservoir, chlorophyll a concentrations appear important (70 µg/L during the dry season) especially in the first five meters of the water column. The phytoplankton community is dominated by Euglenophyta and Cyanobacteria groups typical of eutrophic waters. This study is the first

  20. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoir To Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W. Lynn [University Of Kansas Center For Research, Inc. Lawrence, KS (United States)

    2014-09-30

    1. Drilled, cored, and logged three wells to the basement and collecting more than 2,700 ft of conventional core; obtained 20 mi2 of multicomponent 3D seismic imaging and merged and reprocessed more than 125 mi2 of existing 3D seismic data for use in modeling CO2- EOR oil recovery and CO2 storage in five oil fields in southern Kansas. 2. Determined the technical feasibility of injecting and sequestering CO2 in a set of four depleted oil reservoirs in the Cutter, Pleasant Prairie South, Eubank, and Shuck fields in southwest Kansas; of concurrently recovering oil from those fields; and of quantifying the volumes of CO2 sequestered and oil recovered during the process. 3. Formed a consortium of six oil operating companies, five of which own and operate the four fields. The consortium became part of the Southwest Kansas CO2-EOR Initiative for the purpose of sharing data, knowledge, and interest in understanding the potential for CO2-EOR in Kansas. 4. Built a regional well database covering 30,000 mi2 and containing stratigraphic tops from ~90,000 wells; correlated 30 major stratigraphic horizons; digitized key wells, including wireline logs and sample logs; and analyzed more than 3,000 drill stem tests to establish that fluid levels in deep aquifers below the Permian evaporites are not connected to the surface and therefore pressures are not hydrostatic. Connectivity with the surface aquifers is lacking because shale aquitards and impermeable evaporite layers consist of both halite and anhydrite. 5. Developed extensive web applications and an interactive mapping system that do the following: a. Facilitate access to a wide array of data obtained in the study, including core descriptions and analyses, sample logs, digital (LAS) well logs, seismic data, gravity and magnetics maps, structural and stratigraphic maps, inferred fault traces, earthquakes, Class I and II disposal wells, and

  1. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoir To Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W. Lynn [University Of Kansas Center For Research, Inc. Lawrence, KS (United States); Rush, Jason [University Of Kansas Center For Research, Inc. Lawrence, KS (United States); Raney, Jennifer [University Of Kansas Center For Research, Inc. Lawrence, KS (United States)

    2014-09-30

    1. Drilled, cored, and logged three wells to the basement and collecting more than 2,700 ft of conventional core; obtained 20 mi2 of multicomponent 3D seismic imaging and merged and reprocessed more than 125 mi2 of existing 3D seismic data for use in modeling CO2- EOR oil recovery and CO2 storage in five oil fields in southern Kansas. 2. Determined the technical feasibility of injecting and sequestering CO2 in a set of four depleted oil reservoirs in the Cutter, Pleasant Prairie South, Eubank, and Shuck fields in southwest Kansas; of concurrently recovering oil from those fields; and of quantifying the volumes of CO2 sequestered and oil recovered during the process. 3. Formed a consortium of six oil operating companies, five of which own and operate the four fields. The consortium became part of the Southwest Kansas CO2-EOR Initiative for the purpose of sharing data, knowledge, and interest in understanding the potential for CO2-EOR in Kansas. 4. Built a regional well database covering 30,000 mi2 and containing stratigraphic tops from ~90,000 wells; correlated 30 major stratigraphic horizons; digitized key wells, including wireline logs and sample logs; and analyzed more than 3,000 drill stem tests to establish that fluid levels in deep aquifers below the Permian evaporites are not connected to the surface and therefore pressures are not hydrostatic. Connectivity with the surface aquifers is lacking because shale aquitards and impermeable evaporite layers consist of both halite and anhydrite. 5. Developed extensive web applications and an interactive mapping system that do the following: a. Facilitate access to a wide array of data obtained in the study, including core descriptions and analyses, sample logs, digital (LAS) well logs, seismic data, gravity and magnetics maps, structural and stratigraphic maps, inferred fault traces, earthquakes, Class I and II disposal wells, and

  2. A comparison of single- and multi-site calibration and validation: a case study of SWAT in the Miyun Reservoir watershed, China

    Science.gov (United States)

    Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu

    2017-09-01

    An essential task in evaluating global water resource and pollution problems is to obtain the optimum set of parameters in hydrological models through calibration and validation. For a large-scale watershed, single-site calibration and validation may ignore spatial heterogeneity and may not meet the needs of the entire watershed. The goal of this study is to apply a multi-site calibration and validation of the Soil andWater Assessment Tool (SWAT), using the observed flow data at three monitoring sites within the Baihe watershed of the Miyun Reservoir watershed, China. Our results indicate that the multi-site calibration parameter values are more reasonable than those obtained from single-site calibrations. These results are mainly due to significant differences in the topographic factors over the large-scale area, human activities and climate variability. The multi-site method involves the division of the large watershed into smaller watersheds, and applying the calibrated parameters of the multi-site calibration to the entire watershed. It was anticipated that this case study could provide experience of multi-site calibration in a large-scale basin, and provide a good foundation for the simulation of other pollutants in followup work in the Miyun Reservoir watershed and other similar large areas.

  3. Assessing internal biophysical vulnerability to landslide hazards - a nested catchment approach: Xiangxi Watershed / Three Gorges Reservoir

    Science.gov (United States)

    Wiegand, Matthias; Seeber, Christoph; Hartmann, Heike; Xiang, Wei; King, Lorenz

    2010-05-01

    The Three Gorges dam construction was completed in 2006. Besides the international media, also the responsible authorities and various scholarly communities pay close attention to potential and actual environmental impacts related to the impoundment and development activities. The geo-environment within the Three Gorges region is highly conducive to landslides. Consequently, a scientific monitoring and risk mitigation system was established and is still under development. Risk analysis with regard to gravity driven mass movements is highly complex and strongly site specific - several aspects hamper a universal methodology applicable for landslide risk and site assessment. The interdisciplinary Sino-German Yangtze-Project Research co-operation aims, among others, to support the sustainable cultivation of the newly developed ecosystems within the Yangtze catchments. Land use change and increasing population growth are causing severe pressure on the scarce land resources. Landslides are acknowledged as important threat, hence vulnerability of certain landscape components have to be identified, quantified and monitored. A nested quantitative approach for vulnerability analysis is developed. The applied risk and vulnerability model understands risk as the product of hazard and vulnerability. Whereas vulnerability is characterized by: mass movement intensity and susceptibility of the respective element at risk. The watershed of Xiangxi river serves as study area. In general, catchment approaches intent and proved to be a functional geographical unit for successful integrated resources management. Several limitations with regard to data accessibility, availability and accuracy have to be considered due to restrictions of feasible scales. Comprehensive large-scale site investigations are confined to training areas for model calibration and validation. Remote sensing potentials are utilised for land use/ land cover change analysis and localization of selected elements

  4. Potential accumulation of contaminated sediments in a reservoir of a high-Andean watershed: Morphodynamic connections with geochemical processes

    Science.gov (United States)

    Contreras, María. Teresa; Müllendorff, Daniel; Pastén, Pablo; Pizarro, Gonzalo E.; Paola, Chris; Escauriaza, Cristián.

    2015-05-01

    Rapid changes due to anthropic interventions in high-altitude environments, such as the Altiplano region in South America, require new approaches to understand the connections between physical and geochemical processes. Alterations of the water quality linked to the river morphology can affect the ecosystems and human development in the long term. The future construction of a reservoir in the Lluta River, located in northern Chile, will change the spatial distribution of arsenic-rich sediments, which can have significant effects on the lower parts of the watershed. In this investigation, we develop a coupled numerical model to predict and evaluate the interactions between morphodynamic changes in the Lluta reservoir, and conditions that can potentially desorb arsenic from the sediments. Assuming that contaminants are mobilized under anaerobic conditions, we calculate the oxygen concentration within the sediments to study the interactions of the delta progradation with the potential arsenic release. This work provides a framework for future studies aimed to analyze the complex connections between morphodynamics and water quality, when contaminant-rich sediments accumulate in a reservoir. The tool can also help to design effective risk management and remediation strategies in these extreme environments. This article was corrected on 15 JUNE 2015. See the end of the full text for details.

  5. Assessing the Impact of Climate Change on Extreme Streamflow and Reservoir Operation for Nuuanu Watershed, Oahu, Hawaii

    Science.gov (United States)

    Leta, O. T.; El-Kadi, A. I.; Dulaiova, H.

    2016-12-01

    Extreme events, such as flooding and drought, are expected to occur at increased frequencies worldwide due to climate change influencing the water cycle. This is particularly critical for tropical islands where the local freshwater resources are very sensitive to climate. This study examined the impact of climate change on extreme streamflow, reservoir water volume and outflow for the Nuuanu watershed, using the Soil and Water Assessment Tool (SWAT) model. Based on the sensitive parameters screened by the Latin Hypercube-One-factor-At-a-Time (LH-OAT) method, SWAT was calibrated and validated to daily streamflow using the SWAT Calibration and Uncertainty Program (SWAT-CUP) at three streamflow gauging stations. Results showed that SWAT adequately reproduced the observed daily streamflow hydrographs at all stations. This was verified with Nash-Sutcliffe Efficiency that resulted in acceptable values of 0.58 to 0.88, whereby more than 90% of observations were bracketed within 95% model prediction uncertainty interval for both calibration and validation periods, signifying the potential applicability of SWAT for future prediction. The climate change impact on extreme flows, reservoir water volume and outflow was assessed under the Representative Concentration Pathways of 4.5 and 8.5 scenarios. We found wide changes in extreme peak and low flows ranging from -44% to 20% and -50% to -2%, respectively, compared to baseline. Consequently, the amount of water stored in Nuuanu reservoir will be decreased up to 27% while the corresponding outflow rates are expected to decrease up to 37% relative to the baseline. In addition, the stored water and extreme flows are highly sensitive to rainfall change when compared to temperature and solar radiation changes. It is concluded that the decrease in extreme low and peak flows can have serious consequences, such as flooding, drought, with detrimental effects on riparian ecological functioning. This study's results are expected to aid in

  6. Water- and air-quality and surficial bed-sediment monitoring of the Sweetwater Reservoir watershed, San Diego County, California, 2003-09

    Science.gov (United States)

    Mendez, Gregory O.; Majewski, Michael S.; Foreman, William T.; Morita, Andrew Y.

    2015-01-01

    In 1998, the U.S. Geological Survey, in cooperation with the Sweetwater Authority, began a study to assess the overall health of the Sweetwater watershed in San Diego County, California. This study was designed to provide a data set that could be used to evaluate potential effects from the construction and operation of State Route 125 within the broader context of the water quality and air quality in the watershed. The study included regular sampling of water, air, and surficial bed sediment at Sweetwater Reservoir (SWR) for chemical constituents, including volatile organic compounds (VOCs), base-neutral and acid- extractable organic compounds (BNAs) that include polycyclic aromatic hydrocarbons (PAHs), pesticides, and metals. Additionally, water samples were collected for anthropogenic organic indicator compounds in and around SWR. Background water samples were collected at Loveland Reservoir for VOCs, BNAs, pesticides, and metals. Surficial bed-sediment samples were collected for PAHs, organochlorine pesticides, and metals at Sweetwater and Loveland Reservoirs.

  7. Identifying the Relationships between Water Quality and Land Cover Changes in the Tseng-Wen Reservoir Watershed of Taiwan

    Directory of Open Access Journals (Sweden)

    Hone-Jay Chu

    2013-01-01

    Full Text Available The effects on water quality of land use and land cover changes, which are associated with human activities and natural factors, are poorly identified. Fine resolution satellite imagery provides opportunities for land cover monitoring and assessment. The multiple satellite images after typhoon events collected from 2001 to 2010 covering land areas and land cover conditions are evaluated by the Normalized Difference Vegetation Index (NDVI. The relationship between land cover and observed water quality, such as suspended solids (SS and nitrate-nitrogens (NO3-N, are explored in the study area. Results show that the long-term variations in water quality are explained by NDVI data in the reservoir buffer zones. Suspended solid and nitrate concentrations are related to average NDVI values on multiple spatial scales. Annual NO3-N concentrations are positively correlated with an average NDVI with a 1 km reservoir buffer area, and the SS after typhoon events associated with landslides are negatively correlated with the average NDVI in the entire watershed. This study provides an approach for assessing the influences of land cover on variations in water quality.

  8. The simulation research of dissolved nitrogen and phosphorus non-point source pollution in Xiao-Jiang watershed of Three Gorges Reservoir area.

    Science.gov (United States)

    Wu, Lei; Long, Tian-Yu; Li, Chong-Ming

    2010-01-01

    Xiao-jiang, with a basin area of almost 5,276 km(2) and a length of 182.4 km, is located in the center of the Three Gorges Reservoir Area, and is the largest tributary of the central section in Three Gorges Reservoir Area, farmland accounts for a large proportion of Xiao-jiang watershed, and the hilly cropland of purple soil is much of the farmland of the watershed. After the second phase of water storage in the Three Gorges Reservoir, the majority of sub-rivers in the reservoir area experienced eutrophication phenomenon frequently, and non-point source (NPS) pollution has become an important source of pollution in Xiao-jiang Watershed. Because dissolved nitrogen and phosphorus non-point source pollution are related to surface runoff and interflow, using climatic, topographic and land cover data from the internet and research institutes, the Semi-Distributed Land-use Runoff Process (SLURP) hydrological model was introduced to simulate the complete hydrological cycle of the Xiao-jiang Watershed. Based on the SLURP distributed hydrological model, non-point source pollution annual output load models of land use and rural residents were respectively established. Therefore, using GIS technology, considering the losses of dissolved nitrogen and phosphorus in the course of transport, a dissolved non-point source pollution load dynamic model was established by the organic coupling of the SLURP hydrological model and land-use output model. Through the above dynamic model, the annual dissolved non-point source nitrogen and phosphorus pollution output as well as the load in different types were simulated and quantitatively estimated from 2001 to 2008, furthermore, the loads of Xiao-jiang Watershed were calculated and expressed by temporal and spatial distribution in the Three Gorges Reservoir Area. The simulation results show that: the temporal changes of dissolved nitrogen and phosphorus load in the watershed are close to the inter-annual changes of rainfall runoff, and the

  9. Agricultural non-point source pollution management in a reservoir watershed based on ecological network analysis of soil nitrogen cycling.

    Science.gov (United States)

    Xu, Wen; Cai, Yanpeng; Rong, Qiangqiang; Yang, Zhifeng; Li, Chunhui; Wang, Xuan

    2018-03-01

    The Miyun Reservoir plays a pivotal role in providing drinking water for the city of Beijing. In this research, ecological network analysis and scenario analysis were integrated to explore soil nitrogen cycling of chestnut and Chinese pine forests in the upper basin of the Miyun Reservoir, as well as to seek favorable fertilization modes to reduce agricultural non-point source pollution. Ecological network analysis results showed that (1) the turnover time was 0.04 to 0.37 year in the NH 4 + compartment and were 15.78 to 138.36 years in the organic N compartment; (2) the Finn cycling index and the ratio of indirect to direct flow were 0.73 and 11.92 for the chestnut forest model, respectively. Those of the Chinese pine forest model were 0.88 and 29.23, respectively; and (3) in the chestnut forest model, NO 3 - accounted for 96% of the total soil nitrogen loss, followed by plant N (2%), NH 4 + (1%), and organic N (1%). In the Chinese pine forest, NH 4 + accounted for 56% of the total soil nitrogen loss, followed by organic N (34%) and NO 3 - (10%). Fertilization mode was identified as the main factor affecting soil N export. To minimize NH 4 + and NO 3 - outputs while maintaining the current plant yield (i.e., 7.85e0 kg N/year), a fertilization mode of 162.50 kg N/year offered by manure should be adopted. Whereas, to achieve a maximum plant yield (i.e., 3.35e1 kg N/year) while reducing NH 4 + and NO 3 - outputs, a fertilization mode of 325.00 kg N/year offered by manure should be utilized. This research is of wide suitability to support agricultural non-point source pollution management at the watershed scale.

  10. Historical Streamflow Series Analysis Applied to Furnas HPP Reservoir Watershed Using the SWAT Model

    Directory of Open Access Journals (Sweden)

    Viviane de Souza Dias

    2018-04-01

    Full Text Available Over the last few years, the operation of the Furnas Hydropower Plant (HPP reservoir, located in the Grande River Basin, has been threatened due to a significant reduction in inflow. In the region, hydrological modelling tools are being used and tested to support decision making and water sustainability. In this study, the streamflow was modelled in the area of direct influence of the Furnas HPP reservoir, and the Soil and Water Assessment Tool (SWAT model performance was verified for studies in the region. Analyses of sensitivity and uncertainty were undertaken using the Sequential Uncertainty Fitting algorithm (SUFI-2 with a Calibration Uncertainty Program (SWAT-CUP. The hydrological modelling, at a monthly scale, presented good results in the calibration (NS 0.86, with a slight reduction of the coefficient in the validation period (NS 0.64. The results suggested that this tool could be applied in future hydrological studies in the region of study. With the consideration that special attention should be given to the historical series used in the calibration and validation of the models. It is important to note that this region has high demands for water resources, primarily for agricultural use. Water demands must also be taken into account in future hydrological simulations. The validation of this methodology led to important contributions to the management of water resources in regions with tropical climates, whose climatological and geological reality resembles the one studied here.

  11. Impacts of boreal hydroelectric reservoirs on seasonal climate and precipitation recycling as simulated by the CRCM5: a case study of the La Grande River watershed, Canada

    Science.gov (United States)

    Irambona, C.; Music, B.; Nadeau, D. F.; Mahdi, T. F.; Strachan, I. B.

    2018-02-01

    Located in northern Quebec, Canada, eight hydroelectric reservoirs of a 9782-km2 maximal area cover 6.4% of the La Grande watershed. This study investigates the changes brought by the impoundment of these reservoirs on seasonal climate and precipitation recycling. Two 30-year climate simulations, corresponding to pre- and post-impoundment conditions, were used. They were generated with the fifth-generation Canadian Regional Climate Model (CRCM5), fully coupled to a 1D lake model (FLake). Seasonal temperatures and annual energy budget were generally well reproduced by the model, except in spring when a cold bias, probably related to the overestimation of snow cover, was seen. The difference in 2-m temperature shows that reservoirs induce localized warming in winter (+0.7 ± 0.02 °C) and cooling in the summer (-0.3 ± 0.02 °C). The available energy at the surface increases throughout the year, mostly due to a decrease in surface albedo. Fall latent and sensible heat fluxes are enhanced due to additional energy storage and availability in summer and spring. The changes in precipitation and runoff are within the model internal variability. At the watershed scale, reservoirs induce an additional evaporation of only 5.9 mm year-1 (2%). We use Brubaker's precipitation recycling model to estimate how much of the precipitation is recycled within the watershed. In both simulations, the maximal precipitation recycling occurs in July (less than 6%), indicating weak land-atmosphere coupling. Reservoirs do not seem to affect this coupling, as precipitation recycling only decreased by 0.6% in July.

  12. Aeolian dunes of south-central Sweden

    Science.gov (United States)

    Bernhardson, Martin; Alexanderson, Helena

    2017-04-01

    South-central Sweden is home to a number of small, inactive inland dune fields formed on former glaciofluvial deltas. A characteristic of these dune fields is the generally transverse shape of the dunes, in stark contrast to the rest of Sweden where parabolic dunes are the most common type. One of these dune fields is Bonäsheden in the county of Dalarna. It is the largest continuous dune field in Sweden and covers an area of approximately 15.5 km2. The dune field has the last few years been the target of thorough investigations utilising LiDAR (Light Detection And Ranging) based remote sensing, ground-penetrating radar, luminescence dating and sedimentological field investigations. The results show that the dunes of Bonäsheden and the adjacent dune field of Skattungheden formed mainly by north-westerly winds shortly after the deglaciation of this part of Sweden (10.5 ka), and subsequent events of dune formation were uncommon. Some later episodes of sand drift did occur, but only as minor coversand deposition. The dune field has had a more complex formation than previously thought; a shift in the wind pattern around 10 ka seems to have caused subsequent dunes to have formed by more westerly winds. The reason for this is still not determined, but the increased distance to the Scandinavian Ice Sheet would lessen the capacity of katabatic winds to influence the dune field.

  13. Nuclear Power in South-Central Brazil

    International Nuclear Information System (INIS)

    Cintra do Prado, L.

    1966-01-01

    The region of South-Central Brazil includes the states of Sao Paulo, Rio de Janeiro, Guanabara and Minas Gerais. The most recent power study was made by Canambra Engineering Consultants Limited. This group reported that the public-grid electricity output for the area in 1962 was 2.16 GW (average generation), with an installed capacity of 3.41 GW and annual mean load factor of 63.4; an increase in power requirements for 1970 was forecast, corresponding to an average output of 5.37 GW and an installed capacity of 8.3 GW. This forecast was based on an annual growth rate of 11.9% in generation. ''The energy requirements have grown at an average annual rate of 10.9% since 1955; however, the present forecast is based on the assumption of power being available as required, and hence includes the suppressed demand resulting from existing restrictions in generating and distribution capacity''

  14. High-Functioning Wetland Formed Atop Abandoned Pavement in Eutrophic Reservoir Watershed

    Science.gov (United States)

    Clifford, C.; Heffernan, J. B.

    2017-12-01

    Water scientists and managers regularly observe how wetlands, whether natural or created, can mitigate the influence of artificial impervious surfaces on water quality. However, we rarely study or mention wetlands accidentally (sensu Palta et al. 2017) formed atop impervious surfaces. This silence occurs even though many urbanites have likely noticed sedges rimming a clogged drainage grate or in the low bits of a poorly graded or aging parking lot, or similar. A more extreme example occurs in the Little River Waterfowl Impoundment vicinity of the Butner-Falls of Neuse Game Land in Durham, North Carolina. There, a macadam road that connected local residents and a store, and served as the primary route through the area, by 1910-1920, was apparently abandoned by 1951. Later, damming nearby downstream Falls Lake Reservoir in 1981, and smaller-scale construction locally, apparently increased water table depth and flow exposure. Yet, the road remains largely intact structurally, though mostly buried and sometimes underwater. In a particularly wet segment of the road, surrounded by and partially holding back standing water even in drought, a substantial, mostly native wetland plant community has formed. This community includes trees such as overcup oak (Quercus lyrata) as large as 15 cm in diameter, shrubs such as (Cephalanthus occidentalus), sedges such as woolgrass (Scirpus cyperinus), rushes (multiple Juncus species), grasses such as wood oats (Chasmanthium latifolium), crayfish and fish, and multiple orders of herptiles. The plants grow rooted in fluffy sediment three to rarely more than 20cm deep, over solid pavement. Alongside the old road, the ditches have widened and become shallower and less surficially connected through tree roots and debris dams; they resemble pools. Sediment in these abandoned ditches has accumulated to depths of tens of centimeters, generally reforming a clay-dominated, gleyed soil, in some places buried under more tens of centimeters of very

  15. Characterization of phosphorus leaching from phosphate waste rock in the Xiangxi River watershed, Three Gorges Reservoir, China.

    Science.gov (United States)

    Jiang, Li-Guo; Liang, Bing; Xue, Qiang; Yin, Cheng-Wei

    2016-05-01

    Phosphate mining waste rocks dumped in the Xiangxi River (XXR) bay, which is the largest backwater zone of the Three Gorges Reservoir (TGR), are treated as Type I industry solid wastes by the Chinese government. To evaluate the potential pollution risk of phosphorus leaching from phosphate waste rocks, the phosphorus leaching behaviors of six phosphate waste rock samples with different weathering degrees under both neutral and acidic conditions were investigated using a series of column leaching experiments, following the Method 1314 standard of the US EPA. The results indicate that the phosphorus release mechanism is solubility-controlled. Phosphorus release from waste rocks increases as pH decreases. The phosphorus leaching concentration and cumulative phosphorus released in acidic leaching conditions were found to be one order of magnitude greater than that in neutral leaching conditions. In addition, the phosphorus was released faster during the period when environmental pH turned from weak alkalinity to slight acidity, with this accelerated release period appearing when L/S was in the range of 0.5-2.0 mL/g. In both neutral and acidic conditions, the average values of Total Phosphorus (TP), including orthophosphates, polyphosphates and organic phosphate, leaching concentration exceed the availability by regulatory (0.5 mg/L) in the whole L/S range, suggesting that the phosphate waste rocks stacked within the XXR watershed should be considered as Type II industry solid wastes. Therefore, the phosphate waste rocks deposited within the study area should be considered as phosphorus point pollution sources, which could threaten the adjacent surface-water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Tsengwen Reservoir Watershed Hydrological Flood Simulation Under Global Climate Change Using the 20 km Mesh Meteorological Research Institute Atmospheric General Circulation Model (MRI-AGCM

    Directory of Open Access Journals (Sweden)

    Nobuaki Kimura

    2014-01-01

    Full Text Available Severe rainstorms have occurred more frequently in Taiwan over the last decade. To understand the flood characteristics of a local region under climate change, a hydrological model simulation was conducted for the Tsengwen Reservoir watershed. The model employed was the Integrated Flood Analysis System (IFAS, which has a conceptual, distributed rainfall-runoff analysis module and a GIS data-input function. The high-resolution rainfall data for flood simulation was categorized into three terms: 1979 - 2003 (Present, 2015 - 2039 (Near-future, and 2075 - 2099 (Future, provided by the Meteorological Research Institute atmospheric general circulation model (MRI-AGCM. Ten extreme rainfall (top ten events were selected for each term in descending order of total precipitation volume. Due to the small watershed area the MRI-AGCM3.2S data was downsized into higher resolution data using the Weather Research and Forecasting Model. The simulated discharges revealed that most of the Near-future and Future peaks caused by extreme rainfall increased compared to the Present peak. These ratios were 0.8 - 1.6 (Near-future/Present and 0.9 - 2.2 (Future/Present, respectively. Additionally, we evaluated how these future discharges would affect the reservoir¡¦s flood control capacity, specifically the excess water volume required to be stored while maintaining dam releases up to the dam¡¦s spillway capacity or the discharge peak design for flood prevention. The results for the top ten events show that the excess water for the Future term exceeded the reservoir¡¦s flood control capacity and was approximately 79.6 - 87.5% of the total reservoir maximum capacity for the discharge peak design scenario.

  17. Food habits of Northern Goshawks nesting in south central Wyoming

    Science.gov (United States)

    John R. Squires

    2000-01-01

    Northern Goshawks (Accipiter gentiles) nesting in south central Wyoming consumed at least 33 species of prey; 14 were mammals and 19 were birds. Based on percent occurrence in regurgitated pellets, dominant (>10% frequency) prey species included: red squirrel (Tamiasciurus hudsonicus; present in 50% of pellets), Northern Flicker (Colaptes auratus; 34...

  18. (Coleoptera: Carabidae: Pterostichinae) from south-central Turkey

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... Key words: Amara, Pterostichinae, Carabidae, Turkey. INTRODUCTION. This publication is the second part of a taxonomic and geographical treatment of the Pterostichinae of south- central Turkey, with a focus on sites in the province of. Kahramanmaraş and some of the geographically adjacent provinces.

  19. Influence of Land Use and Watershed Characteristics on Protozoa Contamination in a Potential Drinking Water Resources Reservoir

    Science.gov (United States)

    Relative changes in the microbial quality of Lake Texoma, on the border of Texas and Oklahoma, were investigated by monitoring protozoan pathogens, fecal indicators, and factors influencing the intensity of the microbiological contamination of surface water reservoirs. The waters...

  20. People and dams: environmental and socio-economic changes induced by a reservoir in Fincha'a watershed, western Ethiopia

    NARCIS (Netherlands)

    Bezuayehu, T.O.

    2006-01-01

    Dams that store water for electricity, irrigation, domestic water supply or flood control have been constructed for thousands of years worldwide. In too many cases, an unacceptable and often unnecessary price has been paid by watershed inhabitants to secure dam benefits, especially in social and

  1. Mosquito biodiversity patterns around urban environments in South-central okinawa island, Japan.

    Science.gov (United States)

    Hoshi, Tomonori; Imanishi, Nozomi; Higa, Yukiko; Chaves, Luis Fernando

    2014-12-01

    Okinawa is the largest, most urbanized, and densely populated island in the Ryukyus Archipelago, where mosquito species diversity has been thoroughly studied. However, the south-central Okinawa mosquito fauna has been relatively poorly studied. Here, we present results from a mosquito faunal survey in urban environments of Nishihara city, south-central Okinawa. Mosquitoes were sampled biweekly, from April 2007 to March 2008, at 3 different environments: a forest preserve, an animal farm, and a water reservoir. We employed 4 mosquito collection methods: 1) oviposition traps; 2) light traps; 3) sweep nets; and 4) larval surveys of tree holes, leaf axils, and artificial water containers. We collected a total of 568 adults and 10,270 larvae belonging to 6 genera and 13 species, including 6 species of medical importance: Aedes albopictus, Armigeres subalbatus, Anopheles Hyrcanus group, Culex bitaeniorhynchus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus. Mosquito species composition was similar to data from previous studies in Okinawa Island. The flattening of the species accumulation curve suggests that our diversity sampling was exhaustive with light and oviposition traps, as well as the coincidence between the species richness we found in the field and estimates from the Chao2 index, a theoretical estimator of species richness based on species abundance. This study highlights the importance of combining several sampling techniques to properly characterize regional mosquito fauna and to monitor changes in the presence of mosquito species.

  2. [Ultraviolet-visible (UV-Vis) and fluorescence spectral characteristics of soil dissolved organic matter (DOM) in typical agricultural watershed of Three Gorges Reservoir Region].

    Science.gov (United States)

    Wang, Qi-Lei; Jiang, Tao; Zhao, Zheng; Mu, Zhi-Jian; Wei, Shi-Qiang; Yan, Jin-Long; Liang, Jian

    2015-03-01

    As an important geo-factor to decide the environmental fate of pollutants in watershed, soil dissolved organic matter (DOM) sampled from a typical agricultural watershed in the Three Gorges Reservoir area was investigated using ultraviolet-visible (UV-Vis) and fluorescence spectroscopies, to analyze and discuss the effect of different land uses including forest, cropland, vegetable field and residence, on soil DOM geochemical characteristics. The results showed that significant differences in DOM samples amongst different land uses were observed, and DOM from forest had the highest aromaticity and humification degree, followed by DOM from cropland. Although DOM from vegetable field and residence showed the highest dissolved organic carbon (DOC) concentration (average values 0.81 g x kg(-1) and 0.89 g x kg(-1), respectively), but the aromaticity was lower indicating lower humification, which further suggested that the non-chromophoric component in these DOM samples contributed significantly to total DOM compositions. Additionally, in all DOM samples that were independent of land uses, fluorescence index (FI) values were between 1.4 (terrigenous) and 1.9 (authigenic) , evidently indicating both the allochthonous and autochthonous sources contributed to DOM characteristics. Meanwhile, r(T/C) values in most of samples were higher than 2.0, suggesting that soil DOM in this agricultural watershed was heavily affected by anthropogenic activities such as agricultural cultivation, especially, vegetable field was a good example. Additionally, sensitivities of different special spectral parameters for reflecting the differences of DOM characteristics amongst different land uses were not identical. For example, neither spectral slope ratio (S(R)) nor humification index (HIX) could clearly unveil the various geochemical characteristics of soil DOM from different sources. Thus, simple and single special spectral parameter cannot comprehensively provide the detailed information

  3. A mathematical model of reservoir sediment quality prediction based on land-use and erosion processes in watershed

    Science.gov (United States)

    Junakova, N.; Balintova, M.; Junak, J.

    2017-10-01

    The aim of this paper is to propose a mathematical model for determining of total nitrogen (N) and phosphorus (P) content in eroded soil particles with emphasis on prediction of bottom sediment quality in reservoirs. The adsorbed nutrient concentrations are calculated using the Universal Soil Loss Equation (USLE) extended by the determination of the average soil nutrient concentration in top soils. The average annual vegetation and management factor is divided into five periods of the cropping cycle. For selected plants, the average plant nutrient uptake divided into five cropping periods is also proposed. The average nutrient concentrations in eroded soil particles in adsorbed form are modified by sediment enrichment ratio to obtain the total nutrient content in transported soil particles. The model was designed for the conditions of north-eastern Slovakia. The study was carried out in the agricultural basin of the small water reservoir Klusov.

  4. Mio-Pliocene aridity in the south-central Andes associated with Southern Hemisphere cold periods.

    Science.gov (United States)

    Amidon, William H; Fisher, G Burch; Burbank, Douglas W; Ciccioli, Patricia L; Alonso, Ricardo N; Gorin, Andrew L; Silverhart, Perri H; Kylander-Clark, Andrew R C; Christoffersen, Michael S

    2017-06-20

    Although Earth's climate history is best known through marine records, the corresponding continental climatic conditions drive the evolution of terrestrial life. Continental conditions during the latest Miocene are of particular interest because global faunal turnover is roughly synchronous with a period of global glaciation from ∼6.2-5.5 Ma and with the Messinian Salinity Crisis from ∼6.0-5.3 Ma. Despite the climatic and ecological significance of this period, the continental climatic conditions associated with it remain unclear. We address this question using erosion rates of ancient watersheds to constrain Mio-Pliocene climatic conditions in the south-central Andes near 30° S. Our results show two slowdowns in erosion rate, one from ∼6.1-5.2 Ma and another from 3.6 to 3.3 Ma, which we attribute to periods of continental aridity. This view is supported by synchrony with other regional proxies for aridity and with the timing of glacial ‟cold" periods as recorded by marine proxies, such as the M2 isotope excursion. We thus conclude that aridity in the south-central Andes is associated with cold periods at high southern latitudes, perhaps due to a northward migration of the Southern Hemisphere westerlies, which disrupted the South American Low Level Jet that delivers moisture to southeastern South America. Colder glacial periods, and possibly associated reductions in atmospheric CO 2 , thus seem to be an important driver of Mio-Pliocene ecological transitions in the central Andes. Finally, this study demonstrates that paleo-erosion rates can be a powerful proxy for ancient continental climates that lie beyond the reach of most lacustrine and glacial archives.

  5. Estimating reservoir sedimentation using bathymetric differencing and hydrologic modeling in data scarce Koga watershed, Upper Blue Nile

    Directory of Open Access Journals (Sweden)

    Demesew Alemaw Mhiret

    2016-12-01

    Full Text Available ABSTRACT Modeling sediment accumulation in constructed reservoirs is hampered by lack of historic sediment concentration data in developing countries. Existing models simulate sediment concentration using data generated from sediment rating curves usually defined as a power function of the form S = aQb This often results in residual errors that are not identically distributed throughout the range of stream flow values adding to uncertainty in sediment modeling practices. This research measure accumulated sediment in Koga dam in the upper Blue Nile Basin and use the result to validate a Soil and Water Assessment Tool (SWAT sediment model that uses sediment data from rating curves. Bathymetric differencing of the original and current storage digital elevation models (DEMs indicate that the sediment was accumulating at a rate of 5 ton/ha/year while a calibrated SWAT model resulted in 8.6 ton/ha/year. Given the complicated sediment transport processes that are not fully understood and comparable rates reported in recent studies these results are satisfactory. Keywords: Reservoir sedimentation, Koga reservoir, bathymetry

  6. Post-depositional redistribution of trace metals in reservoir sediments of a mining/smelting-impacted watershed (the Lot River, SW France)

    Energy Technology Data Exchange (ETDEWEB)

    Audry, Stephane, E-mail: audry@lmtg.obs-mip.fr [Universite de Bordeaux, UMR 5805 EPOC, Avenue des facultes, 33405 Talence cedex (France)] [Universite de Limoges, Groupement de Recherche Eau Sol Environnement, IFR 145 GEIST, FST, 123 Avenue, A. Thomas, 87060 Limoges cedex (France)] [Universite de Toulouse, UPS (OMP), LMTG, 14 Av., Edouard Belin, F-31400 Toulouse (France); Grosbois, Cecile [Universite de Limoges, Groupement de Recherche Eau Sol Environnement, IFR 145 GEIST, FST, 123 Avenue, A. Thomas, 87060 Limoges cedex (France)] [Universite Francois-Rabelais de Tours, CNRS/INSU, Universite d' Orleans, UMR 6113 ISTO, FST, Parc Grandmont, F-37200 Tours (France); Bril, Hubert [Universite de Limoges, Groupement de Recherche Eau Sol Environnement, IFR 145 GEIST, FST, 123 Avenue, A. Thomas, 87060 Limoges cedex (France); Schaefer, Joerg [Universite de Bordeaux, UMR 5805 EPOC, Avenue des facultes, 33405 Talence cedex (France); Kierczak, Jakub [Universite de Limoges, Groupement de Recherche Eau Sol Environnement, IFR 145 GEIST, FST, 123 Avenue, A. Thomas, 87060 Limoges cedex (France)] [University of Wroclaw, Institute of Geological Sciences, Cybulskiego 30, 50-205 Wroclaw (Poland); Blanc, Gerard [Universite de Bordeaux, UMR 5805 EPOC, Avenue des facultes, 33405 Talence cedex (France)

    2010-06-15

    Mining/smelting wastes and reservoir sediment cores from the Lot River watershed were studied using mineralogical (XRD, SEM-EDS, EMPA) and geochemical (redox dynamics, selective extractions) approaches to characterize the main carrier phases of trace metals. These two approaches permitted determining the role of post-depositional redistribution processes in sediments and their effects on the fate and mobility of trace metals. The mining/smelting wastes showed heterogeneous mineral compositions with highly variable contents of trace metals. The main trace metal-bearing phases include spinels affected by secondary processes, silicates and sulfates. The results indicate a clear change in the chemical partitioning of trace metals between the reservoir sediments upstream and downstream of the mining/smelting activities, with the downstream sediments showing a 2-fold to 5-fold greater contribution of the oxidizable fraction. This increase was ascribed to stronger post-depositional redistribution of trace metals related to intense early diagenetic processes, including dissolution of trace metal-bearing phases and precipitation of authigenic sulfide phases through organic matter (OM) mineralization. This redistribution is due to high inputs (derived from mining/smelting waste weathering) at the water-sediment interface of (i) dissolved SO{sub 4} promoting more efficient OM mineralization, and (ii) highly reactive trace metal-bearing particles. As a result, the main trace metal-bearing phases in the downstream sediments are represented by Zn- and Fe-sulfides, with minor occurrence of detrital zincian spinels, sulfates and Fe-oxyhydroxides. Sequestration of trace metals in sulfides at depth in reservoir sediments does not represent long term sequestration owing to possible resuspension of anoxic sediments by natural (floods) and/or anthropogenic (dredging, dam flush) events that might promote trace metal mobilization through sulfide oxidation. It is estimated that, during a

  7. Post-depositional redistribution of trace metals in reservoir sediments of a mining/smelting-impacted watershed (the Lot River, SW France)

    International Nuclear Information System (INIS)

    Audry, Stephane; Grosbois, Cecile; Bril, Hubert; Schaefer, Joerg; Kierczak, Jakub; Blanc, Gerard

    2010-01-01

    Mining/smelting wastes and reservoir sediment cores from the Lot River watershed were studied using mineralogical (XRD, SEM-EDS, EMPA) and geochemical (redox dynamics, selective extractions) approaches to characterize the main carrier phases of trace metals. These two approaches permitted determining the role of post-depositional redistribution processes in sediments and their effects on the fate and mobility of trace metals. The mining/smelting wastes showed heterogeneous mineral compositions with highly variable contents of trace metals. The main trace metal-bearing phases include spinels affected by secondary processes, silicates and sulfates. The results indicate a clear change in the chemical partitioning of trace metals between the reservoir sediments upstream and downstream of the mining/smelting activities, with the downstream sediments showing a 2-fold to 5-fold greater contribution of the oxidizable fraction. This increase was ascribed to stronger post-depositional redistribution of trace metals related to intense early diagenetic processes, including dissolution of trace metal-bearing phases and precipitation of authigenic sulfide phases through organic matter (OM) mineralization. This redistribution is due to high inputs (derived from mining/smelting waste weathering) at the water-sediment interface of (i) dissolved SO 4 promoting more efficient OM mineralization, and (ii) highly reactive trace metal-bearing particles. As a result, the main trace metal-bearing phases in the downstream sediments are represented by Zn- and Fe-sulfides, with minor occurrence of detrital zincian spinels, sulfates and Fe-oxyhydroxides. Sequestration of trace metals in sulfides at depth in reservoir sediments does not represent long term sequestration owing to possible resuspension of anoxic sediments by natural (floods) and/or anthropogenic (dredging, dam flush) events that might promote trace metal mobilization through sulfide oxidation. It is estimated that, during a major

  8. Minnesota Watersheds

    Data.gov (United States)

    Minnesota Department of Natural Resources — Statewide minor watershed delineations with major/minor watershed identifiers and names for provinces, major watersheds, and basins. Also included are watershed...

  9. [Temporal and spatial variation of mercury in water of agro-forestry and livestock compound watershed in the three Gorges Reservoir Area].

    Science.gov (United States)

    Zhao, Zheng; Wang, Ya; Mu, Zhi-jian; Wang, Ding-yong

    2015-01-01

    The temporal and spatial distribution of mercury (Hg) in four different sources of stream (aquaculture wastewater, bare land, forestry land and agro-forestry land) and well water of an agro-forestry and livestock compound watershed in the Three Gorge Reservoir region was studied during the period from March 2013 to March 2014. The total mercury (THg) concentrations ranged 9.95-15.26 ng x L(-1) with an average of (11.95 +/- 1.87) ng x L(-1), and the THg concentration decreased in the order of bare land > aquaculture wastewater> forestry land > agro-forestry land > well water. The total methylmercury (TMeHg) concentrations ranged 0.120-0.441 ng x L(-1) with an average of (0.232 +/- 0.099) ng x L(-1), and the TMeHg concentration decreased in the order of aquaculture wastewater > agro-forestry land > forestry land > bare land > well water. THg and TMeHg in well water were both dominated by the dissolved fraction, whereas for other sources of stream, the particulate phase accounted for the major fraction of THg and TMeHg. The THg concentrations in winter and spring were significant higher than those in summer and fall, however, no obvious seasonal trend of TMeHg distribution was observed. Comprehensive analysis showed human activities and weather conditions such as air temperature and precipitation etc. were the main reasons for the difference of temporal and spatial distribution of THg and TMeHg.

  10. Benchmarking Terrestrial Ecosystem Models in the South Central US

    Science.gov (United States)

    Kc, M.; Winton, K.; Langston, M. A.; Luo, Y.

    2016-12-01

    Ecosystem services and products are the foundation of sustainability for regional and global economy since we are directly or indirectly dependent on the ecosystem services like food, livestock, water, air, wildlife etc. It has been increasingly recognized that for sustainability concerns, the conservation problems need to be addressed in the context of entire ecosystems. This approach is even more vital in the 21st century with formidable increasing human population and rapid changes in global environment. This study was conducted to find the state of the science of ecosystem models in the South-Central region of US. The ecosystem models were benchmarked using ILAMB diagnostic package developed as a result of International Land Model Benchmarking (ILAMB) project on four main categories; viz, Ecosystem and Carbon Cycle, Hydrology Cycle, Radiation and Energy Cycle and Climate forcings. A cumulative assessment was generated with weighted seven different skill assessment metrics for the ecosystem models. This synthesis on the current state of the science of ecosystem modeling in the South-Central region of US will be highly useful towards coupling these models with climate, agronomic, hydrologic, economic or management models to better represent ecosystem dynamics as affected by climate change and human activities; and hence gain more reliable predictions of future ecosystem functions and service in the region. Better understandings of such processes will increase our ability to predict the ecosystem responses and feedbacks to environmental and human induced change in the region so that decision makers can make an informed management decisions of the ecosystem.

  11. [Effects of land use and landscape pattern on nitrogen and phosphorus exports in Lanlingxi Watershed of the Three Gorges Reservoir Area, China].

    Science.gov (United States)

    Han, Li-Yang; Huang, Zhi-Lin; Xiao, Wen-Fa; Tian, Yao-Wu; Zeng, Li-Xiong; Wu, Dong

    2014-03-01

    The temporal and spatial characteristics of N, P exports and effects of land use and landscape pattern on N, P exports were analyzed in the Lanlingxi Watershed of the Three Gorges Reservoir Area. The results showed that the TN, TP and NO3(-) -N were mainly generated by non-wood forest, the N, P exports in flood period (June to September) were significantly higher than the non-flood period (January to May). The NH4(+) -N export was derived from the residential area in the non-flood period, while from non-wood forest in the flood period. In addition, the performance of samples N, P exports with forest distributed were lower in both two periods. Also, the proportion of forest significantly negatively correlated with NO3(-) -N, TP in the non-flood period and TN, TP in the flood period. The residential area proportion notably positively correlated with NO3(-) -N, TN in non-flood period and NO3(-) -N, TN, TP in the flood period. The non-wood forest proportion also significantly positively correlated with NH4(+) -N, TN in the flood period. Moreover, PD closely positively correlated with N exports in non-flood period, with NO3(-) -N, NH4(+) -N in flood period. The CONT index strongly negatively correlated with N exports in flood period and TP in non-flood period. However, the proportions of farmland, unused land and the indices of ED were relatively weakened with N, P exports in both periods, while SHMN and water proportion did not show any positive or negative correlation. Moreover, the regression fitting degree of NH4(+)-N was superior to NO3(-) -N, TN and TP with the adjust R2 of 0.885 and 0.969 in two periods, while the regression relation was better than that of non-flood period. The result of redundancy analysis further demonstrated that the landscape fragmentation caused by patches types of different land uses could better explain impacts on the exports of nitrogen and phosphorus. The two canonical axes accumulated explained the 90% proportion of the variables and

  12. Wind energy resource atlas. Volume 7. The south central region

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, R.L.; Graves, L.F.; Sprankle, A.C.; Elliott, D.L.; Barchet, W.R.; George, R.L.

    1981-03-01

    This atlas of the south central region combines seven collections of wind resource data: one for the region, and one for each of the six states (Arkansas, Kansas, Louisiana, Missouri, Oklahoma, and Texas). At the state level, features of the climate, topography, and wind resource are discussed in greater detail than that provided 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 hourly average wind speed for each season. Other graphs present speed, direction, and duration frequencies of the wind at these locations.

  13. Status of Wheeler Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  14. The phylogeography and spatiotemporal spread of south-central skunk rabies virus.

    Directory of Open Access Journals (Sweden)

    Natalia A Kuzmina

    Full Text Available The south-central skunk rabies virus (SCSK is the most broadly distributed terrestrial viral lineage in North America. Skunk rabies has not been efficiently targeted by oral vaccination campaigns and represents a natural system of pathogen invasion, yielding insights to rabies emergence. In the present study we reconstructed spatiotemporal spread of SCSK in the whole territory of its circulation using a combination of Bayesian methods. The analysis based on 241 glycoprotein gene sequences demonstrated that SCSK is much more divergent phylogenetically than was appreciated previously. According to our analyses the SCSK originated in the territory of Texas ~170 years ago, and spread geographically during the following decades. The wavefront velocity in the northward direction was significantly greater than in the eastward and westward directions. Rivers (except the Mississippi River and Rio Grande River did not constitute significant barriers for epizootic spread, in contrast to deserts and mountains. The mean dispersal rate of skunk rabies was lower than that of the raccoon and fox rabies. Viral lineages circulate in their areas with limited evidence of geographic spread during decades. However, spatiotemporal reconstruction shows that after a long period of stability the dispersal rate and wavefront velocity of SCSK are increasing. Our results indicate that there is a need to develop control measures for SCSK, and suggest how such measure can be implemented most efficiently. Our approach can be extrapolated to other rabies reservoirs and used as a tool for investigation of epizootic patterns and planning interventions towards disease elimination.

  15. The phylogeography and spatiotemporal spread of south-central skunk rabies virus.

    Science.gov (United States)

    Kuzmina, Natalia A; Lemey, Philippe; Kuzmin, Ivan V; Mayes, Bonny C; Ellison, James A; Orciari, Lillian A; Hightower, Dillon; Taylor, Steven T; Rupprecht, Charles E

    2013-01-01

    The south-central skunk rabies virus (SCSK) is the most broadly distributed terrestrial viral lineage in North America. Skunk rabies has not been efficiently targeted by oral vaccination campaigns and represents a natural system of pathogen invasion, yielding insights to rabies emergence. In the present study we reconstructed spatiotemporal spread of SCSK in the whole territory of its circulation using a combination of Bayesian methods. The analysis based on 241 glycoprotein gene sequences demonstrated that SCSK is much more divergent phylogenetically than was appreciated previously. According to our analyses the SCSK originated in the territory of Texas ~170 years ago, and spread geographically during the following decades. The wavefront velocity in the northward direction was significantly greater than in the eastward and westward directions. Rivers (except the Mississippi River and Rio Grande River) did not constitute significant barriers for epizootic spread, in contrast to deserts and mountains. The mean dispersal rate of skunk rabies was lower than that of the raccoon and fox rabies. Viral lineages circulate in their areas with limited evidence of geographic spread during decades. However, spatiotemporal reconstruction shows that after a long period of stability the dispersal rate and wavefront velocity of SCSK are increasing. Our results indicate that there is a need to develop control measures for SCSK, and suggest how such measure can be implemented most efficiently. Our approach can be extrapolated to other rabies reservoirs and used as a tool for investigation of epizootic patterns and planning interventions towards disease elimination.

  16. Occurrence of antibiotics in an agricultural watershed in south-central Idaho

    Science.gov (United States)

    The polar organic compound integrative sampler (POCIS) is a tool that has been effectively used to passively sample organic pollutants in water. In this study, POCIS were used to investigate the occurrence of 21 veterinary and human antibiotics and a beta agonist (ractopamine) in irrigation return f...

  17. Effect of road salt application on seasonal chloride concentrations and toxicity in south-central Indiana streams.

    Science.gov (United States)

    Gardner, Kristin M; Royer, Todd V

    2010-01-01

    Contemporary information on road salt runoff is needed for management of water resources in regions experiencing urbanization and increased road density. We investigated seasonal Cl(-) concentrations among five streams in south-central Indiana that drained watersheds varying in degree of urbanization and ranging in size from 9.3 to 27 km(2). We also conducted acute toxicity tests with Daphnia pulex to assess the potential effects of the observed Cl(-) concentrations on aquatic life. Periods of elevated Cl(-) concentrations were observed during the winters of 2007-08 and 2008-09 at all sites except the reference site. The highest Cl(-) concentration observed during the study was 2100 mg L(-1) and occurred at the most urbanized site. The Cl(-) concentration at the reference site never exceeded 22 mg L(-1). The application of road salt caused large increases in stream Cl(-) concentrations, but the elevated Cl(-) levels did not appear to be a significant threat to aquatic life based on our toxicity testing. Only the most urbanized site showed evidence of salt retention within the watershed, whereas the other sites exported the road salt relatively quickly after its application, suggesting storm drains and impervious surfaces minimized interaction between soils and salt-laden runoff. During winter at these sites, the response in stream Cl(-) concentrations appeared to be controlled by the timing and intensity of road salt application, the magnitude of precipitation, and the occurrence of air temperatures that caused snowmelt and generated runoff.

  18. Effects of Drought and Water Resource Management on Biophysical and Sociocultural Ecosystem Services in South-Central United States

    Science.gov (United States)

    Julian, J.; Castro, A.; Vaughn, C.; Atkinson, C.

    2014-12-01

    South-Central United States is one of the fastest growing regions in the nation; however, it is experiencing water supply limitations. In response, multiple interests have focused on the Kiamichi River watershed in southeast Oklahoma as a future inter-basin water supply. The Kiamichi River provides many ecosystem services, including freshwater provision to 19 cities/towns, outdoor recreation hub for the South-Central U.S., cultural capital of the Choctaw Indian Nation, and a national biodiversity hotspot. With multiple recent stressors, these ecosystem services are highly threatened. Here we present how drought and water management have impacted these benefits over the past 20 years. First, we assessed the river's sensitivity to drought (which is cyclical) and water regulation (which has increased over the past three decades). Second, we analyzed how these hydrologic changes have impacted freshwater habitat, focusing on mussels because of their sensitivity to flow alterations and because they provide additional ecosystem services such as biofiltration, nutrient recycling/storage, and cultural resources. Third, we performed a sociocultural valuation for a suite of ecosystem services provided by the Kiamichi River watershed, including 505 interviews of five different ecosystem services beneficiary (ESB) groups. We obtained ESB perceptions on how ecosystem services changed with different flow conditions and water management strategies. Analyses revealed that increased regulation (fewer dam releases) has caused the Kiamichi River to have long no flow periods during droughts (e.g. 176 days with no flow in 2006). These long dry periods have been the main culprit for a 60% decline in mussel biomass over the past 20 years, and subsequent large losses in biofiltration and nutrient recycling. Interestingly, ESBs perceived similar losses of ecosystem services. Without being provided any information on flow, more than half of the ESBs believed that water supply, freshwater

  19. Magnetic, Electromagnetic, and Bathymetric Survey of the Lake of the Arbuckles, South-Central Oklahoma

    Science.gov (United States)

    Scheirer, D. S.; Smith, D. V.; Coffee, R.; Cason, J.

    2009-12-01

    In August 2009, we conducted a week-long geophysical and sonar survey of the Lake of the Arbuckles, within Chickasaw National Recreation Area in south-central Oklahoma. In this region, Pennsylvanian-aged orogenic deformation and sedimentation created the conditions that now govern the groundwater recharge, storage, and flow in the Arbuckle-Simpson aquifer, one of the most important bedrock aquifers in Oklahoma. The Lake of the Arbuckles reservoir, filled about 40 years ago, occupies an area where two major faults disrupt the geologic units that constitute the aquifer. The Reagan fault and the Mill Creek fault are hypothesized to intersect beneath the lake, based on available geologic exposures and inferences from gravity, magnetic, and helicopter electromagnetic (EM) observations in areas surrounding the lake. To understand the obscured geometry of these faults, we developed a pontoon-raft to carry a broad-band (15 kHz - 135 kHz) EM bird and a cesium-vapor magnetic sensor across the lake. We towed the raft 15 m behind a small boat to minimize EM and magnetic interference from the vessel, and we collected data on 200-m-spaced transects across much of the lake. The Reagan fault has a large electrical conductivity contrast and magnetic signature due to its juxtaposition at shallow depth of magnetic Proterozoic basement rocks with Paleozoic carbonate and clastic rocks. Initial results will show how the lake survey magnetic transects help to define the location of this fault beneath the lake. In addition, we collected dual-frequency sonar data to map the present-day bathymetry of the lake, and we collected vertical, water-column profiles of sound velocity, conductivity, temperature, pH, redox potential, and dissolved oxygen. The water-column profiles allow correction of the sonar travel-times to depth and estimation of the EM response of the lake water, which will be essential in later inversion modeling of the EM data. In addition, comparisons of the present

  20. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  1. Land use patterns, ecoregion, and microcystin relationships in U.S. lakes and reservoirs: a preliminary evaluation

    Science.gov (United States)

    Beaver, John R.; Manis, Erin E.; Loftin, Keith A.; Graham, Jennifer L.; Pollard, Amina I.; Mitchell, Richard M.

    2014-01-01

    A statistically significant association was found between the concentration of total microcystin, a common class of cyanotoxins, in surface waters of lakes and reservoirs in the continental U.S. with watershed land use using data from 1156 water bodies sampled between May and October 2007 as part of the USEPA National Lakes Assessment. Nearly two thirds (65.8%) of the samples with microcystin concentrations ≥1.0 μg/L (n = 126) were limited to three nutrient and water quality-based ecoregions (Corn Belt and Northern Great Plains, Mostly Glaciated Dairy Region, South Central Cultivated Great Plains) in watersheds with strong agricultural influence. canonical correlation analysis (CCA) indicated that both microcystin concentrations and cyanobacteria abundance were positively correlated with total nitrogen, dissolved organic carbon, and temperature; correlations with total phosphorus and water clarity were not as strong. This study supports a number of regional lake studies that suggest that land use practices are related to cyanobacteria abundance, and extends the potential impacts of agricultural land use in watersheds to include the production of cyanotoxins in lakes.

  2. A Watershed Cooperative Addresses Short and Long-Term Perspectives for the Management of Harmful Algae at a Southwestern Ohio Drinking Water Reservoir

    Science.gov (United States)

    The multi-agency East Fork Watershed Cooperative (EFWCoop) has focused discussion and consequent leveraged monitoring efforts to understand how to ensure water safety in the short term. The EFWCoop is also collecting the dense data sets required to consider potential options for...

  3. Streamflow gain and loss and water quality in the upper Nueces River Basin, south-central Texas, 2008-10

    Science.gov (United States)

    Banta, J. Ryan; Lambert, Rebecca B.; Slattery, Richard N.; Ockerman, Darwin J.

    2012-01-01

    The U.S. Geological Survey-in cooperation with the U.S. Army Corps of Engineers, The Nature Conservancy, the Real Edwards Conservation and Reclamation District, and the Texas Parks and Wildlife Department-investigated streamflow gain and loss and water quality in the upper Nueces River Basin, south-central Texas, specifically in the watersheds of the West Nueces, Nueces, Dry Frio, Frio, and Sabinal Rivers upstream from the Edwards aquifer outcrop. Streamflow in these rivers is sustained by groundwater contributions (for example, from springs) and storm runoff from rainfall events. To date (2012), there are few data available that describe streamflow and water-quality conditions of the rivers within the upper Nueces River Basin. This report describes streamflow gain-loss characteristics from three reconnaissance-level synoptic measurement surveys (hereinafter referred to as "surveys") during 2008-10 in the upper Nueces River Basin. To help characterize the hydrology, groundwater-level measurements were made, and water-quality samples were collected from both surface-water and groundwater sites in the study area from two surveys during 2009-10. The hydrologic (streamflow, springflow, and groundwater) measurements were made during three reconnaissance-level synoptic measurement surveys occurring in July 21-23, 2008; August 8-18, 2009; and March 22-24, 2010. These survey periods were selected to represent different hydrologic conditions. Streamflow gains and losses were based on streamflow and springflow measurements made at 74 sites in the study area, although not all sites were measured during each survey. Possible water chemistry relations among sample types (streamflow, springflow, or groundwater), between surveys, and among watersheds were examined using water-quality samples collected from as many as 20 sites in the study area.

  4. Neurocysticercosos in South-Central America and the Indian Subcontinent: a comparative evaluation

    Directory of Open Access Journals (Sweden)

    Gagandeep Singh

    1997-09-01

    Full Text Available Neurocysticercosis is an important public health problem in South-Central America and South Asia. A review of the differences in epidemiological and clinical attributes of cysticercosis and taeniasis in South Central America and India, respectively, is undertaken in the present communication. Intestinal taeniasis is hyperendemic in several American countries. In comparison, the prevalence of Taenia solium infestation is lower in India. The clinical manifestations in several American neurocysticercosis series comprise epilepsy, intracranial hypertension and meningeal - racemose cysticercosis, in roughly equal proportions. An overwhelming majority of the Indian subjects present with seizures. The commonest pathological substrate of the disorder in Indian patients is the solitary parenchymal degenerating cyst. The reasons for the predominance of solitary forms in India, and of multilesional forms in South Central America are discussed. The magnitude of Taenia solium infestation and the frequency of pork consumption in a given population appear to influence the quantum of cyst load in affected individuals.

  5. GREYBULL SANDSTONE PETROLEUM POTENTIAL ON THE CROW INDIAN RESERVATION, SOUTH-CENTRAL MONTANA

    Energy Technology Data Exchange (ETDEWEB)

    David A. Lopez

    2000-12-14

    Evaluation of the Lower Cretaceous Greybull Sandstone on the Crow Indian Reservation for potential stratigraphic traps in the valley-fill sandstone was the focus of this project. The Crow Reservation area, located in south-central Montana, is part of the Rocky Mountain Foreland structural province, which is characterized by Laramide uplifts and intervening structural basins. The Pryor and Bighorn mountains, like other foreland uplifts, are characterized by asymmetrical folds associated with basement-involved reverse faults. The reservation area east of the mountains is on the northwestern flank of the Powder River Basin. Therefore, regional dips are eastward and southeastward; however, several prominent structural features interrupt these regional dips. The nearly 4,000 mi{sup 2} reservation is under explored but has strong potential for increased oil and gas development. Oil and gas production is well established in the Powder River Basin of Wyoming to the south as well as in the areas north and west of the reservation. However, only limited petroleum production has been established within the reservation. Geologic relations and trends indicate strong potential for oil and gas accumulations, but drilling has been insufficient for their discovery. The Greybull Sandstone, which is part of the transgressive systems tract that includes the overlying Fall River Sandstone, was deposited on a major regional unconformity. The erosional surface at the base of the Greybull Sandstone is the +100 Ma, late Aptian-Early Albian regional unconformity of Weimer (1984). This lowstand erosional surface was controlled by a basin-wide drop in sea level. In areas where incised Greybull channels are absent, the lowstand erosional unconformity is at the base of the Fall River Sandstone and equivalent formations. During the pre-Greybull lowstand, sediment bypassed this region. In the subsequent marine transgression, streams began to aggrade and deposit sand of the lower Greybull Sandstone

  6. Hydrology of the San Luis Valley, south-central Colorado

    Science.gov (United States)

    Emery, P.A.; Boettcher, A.J.; Snipes, R.J.; Mcintyre, H.J.

    1969-01-01

    An investigation of the water resources of the Colorado part of the San Luis Valley was begun in 1966 by the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board. (See index map, fig. 1). The purpose of the investigation is to provide information for planning and implementing improved water-development and management practices. The major water problems in the San Luis Valley include (1) waterlogging, (2) waste of water by nonbeneficial evapotranspiration, (3) deterioration of ground-water chemical quality, and (4) failure of Colorado to deliver water to New Mexico and Texas in accordance with the Rio Grande Compact. This report describes the hydrologic environment, extent of water-resource development, and some of the problems related to that development. Information presented is based on data collected from 1966 to 1968 and on previous studies. Subsequent reports are planned as the investigation progresses. The San Luis Valley extends about 100 miles from Poncha Pass near the northeast corner of Saguache County, Colo., to a point about 16 miles south of the Colorado-New Mexico State line. The total area is 3,125 square miles, of which about 3,000 are in Colorado. The valley is nearly flat except for the San Luis Hills and a few other small areas. The Colorado part of the San Luis Valley, which is described in this report, has an average altitude of about 7,700 feet. Bounding the valley on the west are the San Juan Mountains and on the east the Sangre de Cristo Mountains. Most of the valley floor is bordered by alluvial fans deposited by streams originating in the mountains, the most extensive being the Rio Grande fan (see block diagram, fig. 2 in pocket). Most of the streamflow is derived from snowmelt from 4,700 square miles of watershed in the surrounding mountains. The northern half of the San Luis Valley is internally drained and is referred to as the closed basin. The lowest part of this area is known locally as the "sump." The

  7. Lichen communities and species indicate climate thresholds in southeast and south-central Alaska, USA

    Science.gov (United States)

    Heather T. Root; Bruce. McCune; Sarah. Jovan

    2014-01-01

    Because of their unique physiology, lichen communities are highly sensitive to climatic conditions,making them ideal bioindicators for climate change. Southeast and south-central Alaska host diverse and abundant lichen communities and are faced with a more rapidly changing climate than many more southerly latitudes. We develop sensitive lichen-based indicators for...

  8. Economic factors influencing land use changes in the South-Central United States

    Science.gov (United States)

    Ralph J. Alig; Fred C. White; Brian C. Murray

    1988-01-01

    Econometric models of land use change were estimated for two physiographic regions in the South-Central United States. Results are consistent-with the economic hierarchy of land use, with population and personal income being significant explanatory variables. Findings regarding the importance of relative agricultural and forestry market-based incomes in influencing...

  9. Abundance of Armillaria within old-growth eastern hemlock stands in South-Central Pennsylvania

    Science.gov (United States)

    Matthew S. Fromm; Donald D. Davis

    2007-01-01

    Abstract—In early summer 2002, 329 soil-sampling pits were dug within an old-growth, eastern hemlock (Tsuga canadensis [L.] Carrière) stand in south-central Pennsylvania recently infested with the hemlock woolly adelgid (Adelges tsugae Annand). For comparison, 199 similar pits were dug in an adjacent hardwood stand. Rhizomorphs of...

  10. Attractant semiochemicals of the engraver beetle, Ips perturbatus, in south-central and interior Alaska.

    Science.gov (United States)

    Edward H. Holsten; Roger E. Burnside; Steven J. Seybold

    2000-01-01

    From 1996 through 1999, field tests of various engraver beetle (Ips perturbatus (Eichhoff)) semiochemicals in funnel traps were conducted in south-central and interior Alaska in stands of Lutz (Picea xlutzii Little) and white spruce (P.glauca (Moench) Voss). The European spruce beetle (I....

  11. Historical trends and projections of land use for the South-Central United States.

    Science.gov (United States)

    SoEun Ahn; Andrew J. Plantinga; Ralph J. Alig

    2000-01-01

    This report presents historical trends and future projections of forest, agricultural, and urban and other land uses for the South-Central United States. A land use share model is used to investigate the relation between the areas of land in alternative uses and economic and demographic factors influencing land use decisions. Two different versions of the empirical...

  12. Temporal effects of mechanical treatment on winter moose browse in south-central Alaska

    Science.gov (United States)

    Sharon Smythe; Dana Sanchez; Ricardo Mata-Gonzalez

    2015-01-01

    Sites containing winter browse species utilized by moose on the Copper River Delta of south-central Alaska were mechanically treated (hydraulic-axed) to counteract possible earthquake related increases in less-preferred forage species, and to measure treatment effects on biomass, height, nutritional quality (crude protein, lignin, and tannin), utilization, and snow...

  13. Forest health restoration in south-central Alaska: a problem analysis.

    Science.gov (United States)

    Darrell W. Ross; Gary E. Daterman; Jerry L. Boughton; Thomas M. Quigley

    2001-01-01

    A spruce beetle outbreak of unprecedented size and intensity killed most of the spruce trees on millions of acres of forest land in south-central Alaska in the 1990s. The tree mortality is affecting every component of the ecosystem, including the socioeconomic culture dependent on the resources of these vast forests. Based on information obtained through workshops and...

  14. An Examination of Social Media Policy Usage of South Central United States' Universities

    Science.gov (United States)

    Eaton, Virginia J.; Luse, Donna W.; Hodge, Thomas G.

    2012-01-01

    Since the use of social media tools by universities has expanded exponentially, a university can easily find itself in a precarious situation in a moment's notice because social media tools have been used inadvertently. This study investigated the social media policies of AACSB-International accredited schools in the SREB South Central Region of…

  15. Geological analysis of paleozoic large-scale faulting in the south-central Pyrenees

    NARCIS (Netherlands)

    Speksnijder, A.

    1986-01-01

    Detailed structural and sedimentological analysis reveals the existence of an east-west directed fundamental fault zone in the south-central Pyrenees, which has been intermittently active from (at least) the Devonian on. Emphasis is laid on the stUdy of fault-bounded post-Variscan (StephanoPermian)

  16. Geological analysis of paleozoic large-scale faulting in the south-central Pyrenees

    NARCIS (Netherlands)

    Speksnijder, A.

    1986-01-01

    Detailed structural and sedimentological analysis reveals the existence of an east-west directed fundamental fault zone in the south-central Pyrenees, which has been intermittently active from (at least) the Devonian on. Emphasis is laid on the stUdy of fault-bounded post-Variscan

  17. Reservoir site evaluation through routing | Ogunlela | Journal of ...

    African Journals Online (AJOL)

    Reservoir routing was conducted for site evaluation of a proposed surface reservoir to be located in an ungauged watershed. The study was part of an integrated approach to the development of the watershed. Nash's synthetic hydrograph technique was used in developing the unit hydrograph, from which the 25-yr, 24-hr ...

  18. The impacts of a linear wastewater reservoir on groundwater recharge and geochemical evolution in a semi-arid area of the Lake Baiyangdian watershed, North China Plain

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shiqin [Faculty of Horticulture, Chiba University, Matsudo-City 271-8510 (Japan); Tang, Changyuan, E-mail: cytang@faculty.chiba-u.jp [Faculty of Horticulture, Chiba University, Matsudo-City 271-8510 (Japan); Song, Xianfang [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Wang, Qinxue [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); Zhang, Yinghua [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Yuan, Ruiqiang [College of Environment and Resources, Shanxi University (China)

    2014-06-01

    Sewage leakage has become an important source of groundwater recharge in urban areas. Large linear wastewater ponds that lack anti-seepage measures can act as river channels that cause the deterioration of groundwater quality. This study investigated the groundwater recharge by leakage of the Tanghe Wastewater Reservoir, which is the largest industrial wastewater channel on the North China Plain. Additionally, water quality evolution was investigated using a combination of multivariate statistical methods, multi-tracers and geochemical methods. Stable isotopes of hydrogen and oxygen indicated high levels of wastewater evaporation. Based on the assumption that the wastewater was under an open system and fully mixed, an evaporation model was established to estimate the evaporation of the wastewater based on isotope enrichments of the Rayleigh distillation theory using the average isotope values for dry and rainy seasons. Using an average evaporation loss of 26.5% for the input wastewater, the estimated recharge fraction of wastewater leakage and irrigation was 73.5% of the total input of wastewater. The lateral regional groundwater inflow was considered to be another recharge source. Combing the two end-members mix model and cluster analysis revealed that the mixture percentage of the wastewater decreased from the Highly Affected Zone (76%) to the Transition Zone (5%). Ion exchange and redox reaction were the dominant geochemical processes when wastewater entered the aquifer. Carbonate precipitation was also a major process affecting evolution of groundwater quality along groundwater flow paths. - Highlights: • An unlined wastewater reservoir caused the deterioration of groundwater quality. • An evaporation fraction was estimated by Rayleigh distillation theory of isotopes. • 73.5% of wastewater recharge to groundwater by leakage and irrigation infiltration. • The region influenced by wastewater was divided into four subzones. • Mixing, ion exchange, and

  19. Infectious etiologies of acute febrile illness among patients seeking health care in south-central Cambodia.

    Science.gov (United States)

    Kasper, Matthew R; Blair, Patrick J; Touch, Sok; Sokhal, Buth; Yasuda, Chadwick Y; Williams, Maya; Richards, Allen L; Burgess, Timothy H; Wierzba, Thomas F; Putnam, Shannon D

    2012-02-01

    The agents of human febrile illness can vary by region and country suggesting that diagnosis, treatment, and control programs need to be based on a methodical evaluation of area-specific etiologies. From December 2006 to December 2009, 9,997 individuals presenting with acute febrile illness at nine health care clinics in south-central Cambodia were enrolled in a study to elucidate the etiologies. Upon enrollment, respiratory specimens, whole blood, and serum were collected. Testing was performed for viral, bacterial, and parasitic pathogens. Etiologies were identified in 38.0% of patients. Influenza was the most frequent pathogen, followed by dengue, malaria, and bacterial pathogens isolated from blood culture. In addition, 3.5% of enrolled patients were infected with more than one pathogen. Our data provide the first systematic assessment of the etiologies of acute febrile illness in south-central Cambodia. Data from syndromic-based surveillance studies can help guide public health responses in developing nations.

  20. Active deformation processes across a megathrust-segment boundary, south-central Chile

    OpenAIRE

    M. Moreno; Juergen Klotz; D. Melnick; J. Bolte; Helmut Echtler; K. Bataille

    2009-01-01

    The south-central Chile margin is an active plate boundary where a variety of tectonic processes, including postseismic mantle relaxation, interseismic strain accumulation, sliver motions and crustal faulting are documented. GPS data and finite-element models with complex geometries are presented to gain insight into the active deformation in the vicinity of two megathrust-earthquake segments: the Valdivia and Concepción rupture zones. GPS vectors are heterogeneously distributed in two domain...

  1. Forearc uplift rates deduced from sediment cores of two coastal lakes in south-central Chile

    OpenAIRE

    Stefer, S.; Moernaut, J.; Melnick, D.; Echtler, H. P.; Arz, H. W.; Lamy, Frank; De Batist, M.; Oncken, O.; Haug, G. H.

    2010-01-01

    The present paper introduces a new approach for deriving information about local forearc tectonics and related uplift rates based on the study of lake sediments. We investigated two coastal lakes at the south-central Chile margin, lakes Lanalhue and Lleu Lleu, located south of the Arauco Peninsula (38°S). Both lakes developed within the valleys of ancient rivers that once drained to the Pacific Ocean, being subsequently dammed by rising sills in the late Pleistocene/early Holocene. Seismic pr...

  2. Fire and climate suitability for woody vegetation communities in the south central United States

    Science.gov (United States)

    Stroh, Esther; Struckhoff, Matthew; Stambaugh, Michael C.; Guyette, Richard P.

    2018-01-01

    Climate and fire are primary drivers of plant species distributions. Long-term management of south central United States woody vegetation communities can benefit from information on potential changes in climate and fire frequencies, and how these changes might affect plant communities. We used historical (1900 to 1929) and future (2040 to 2069 and 2070 to 2099) projected climate data for the conterminous US to estimate reference and future fire probabilities

  3. Seroprevalence and awareness of porcine cysticercosis across different pig production systems in south-central Cambodia

    Directory of Open Access Journals (Sweden)

    Aderosoye Adenuga

    2018-02-01

    Conclusions: Despite most pigs being kept confined in pens rather than raised in free-roaming systems, porcine cysticercosis appears to be endemic in south-central Cambodia and is associated with smallholder production. Further investigation is needed to identify which Taenia species are causing infections among pigs, and how seroprevalence and zoonotic risk may vary across the country, to understand the risks to public health and assess where interventions might be needed.

  4. Tree species composition and structure in an old bottomland hardwood forest in south-central Arkansas

    Science.gov (United States)

    Brian Roy Lockhart; James M. Guldin; Thomas Foti

    2010-01-01

    Tree species composition and structure was determined for an old bottomland hardwood forest located in the Moro Creek Bottoms Natural Area in south-central Arkansas. Diversity for this forest was high with species richness ranging from 33 for the overstory and sapling strata to 26 for the seedling stratum and Shannon-Weiner values of 2.54 to 1.02 for the overstory and...

  5. Climate variability and sedimentation of a hydropower reservoir

    International Nuclear Information System (INIS)

    Riedel, M.

    2008-01-01

    As part of the relicensing of a large Hydroelectric Project in the central Appalachians, large scale watershed and reservoir sedimentation models were developed to forecast potential sedimentation scenarios. The GIS based watershed model was spatially explicit and calibrated to long term observed data. Potential socio/economic development scenarios were used to construct future watershed land cover scenarios. Climatic variability and potential change analysis were used to identify future climate regimes and shifts in precipitation and temperature patterns. Permutations of these development and climate changes were forecasted over 50 years and used to develop sediment yield regimes to the project reservoir. Extensive field work and reservoir survey, including current and wave instrumentation, were used to characterize the project watershed, rivers and reservoir hydrodynamics. A fully 3 dimensional hydrodynamic reservoir sedimentation model was developed for the project and calibrated to observed data. Hydrologic and sedimentation results from watershed forecasting provided boundary conditions for reservoir inputs. The calibrated reservoir model was then used to forecast changes in reservoir sedimentation and storage capacity under different future climate scenarios. Results indicated unique zones of advancing sediment deltas and temporary storage areas. Forecasted changes in reservoir bathymetry and sedimentation patterns were also developed for the various climate change scenarios. The warmer and wetter scenario produced sedimentation impacts similar to extensive development under no climate change. The results of these analyses are being used to develop collaborative watershed and soil conservation partnerships to reduce future soil losses and reservoir sedimentation from projected development. (author)

  6. Tribal engagement strategy of the South Central Climate Science Center, 2014

    Science.gov (United States)

    Andrews, William J.; Taylor, April; Winton, Kimberly T.

    2014-01-01

    The South Central Climate Science Center was established by the U.S. Department of the Interior in 2012 to increase understanding of climate change and coordinate an effective response to climate-change effects on Native American tribes and natural and cultural resources that the Department manages. The eight regional Climate Science Centers of the U.S. Department of the Interior work closely with natural-resource management agencies, university researchers, and others such as tribes and private landowners on climate-change issues. The relatively large number of Native Americans in the south central United States and their special knowledge of changing ecosystems make working with tribes and tribal members on climate-change issues particularly important in this part of the Nation. This circular describes priorities of the South Central Climate Science Center and provides information about resources available from Climate Science Centers and partner agencies regarding climate change. The circular also describes how this Climate Science Center, tribes and tribal members, and others can collaborate to minimize potential harmful effects of climate change on human society and our surrounding ecosystems.

  7. Development of a Geologic Exploration Model foe the Permo-Pennsylvanian Petroleum System in South-Central Montana

    Energy Technology Data Exchange (ETDEWEB)

    David A. Lopez

    2007-06-30

    presented: migration occurred (1) before mid-Jurassic erosion produced a major regional unconformity or (2) about 82 million years ago. Migration pre-Laramide occurred because oil in both the Bighorn Basin and the Powder River Basin are part of the same petroleum system. Geochemical analyses of oils from producing fields across the region show the oils are all similar and have the same source and generation history. No Phosphoria source rocks exist in the project area of south-central Montana, requiring that oil migrated from distant source areas, probably in central and southwestern Wyoming. Oil shows and production in the Tensleep are absent in the northern part of the project area. This appears to be controlled by the merging of the top of the Tensleep Sandstone and the Jurassic unconformity (top of the Triassic Chugwater Formation). There should be potential for the discovery of oil in Tensleep stratigraphic traps or combination traps everywhere south of the Jurassic-Pennsylvanian Isopach zero contour except where the Tensleep has been exposed by uplift and erosion. Known Tensleep fields in south-central Montana are generally small in area, which agrees with outcrop studies that show eolian dune sequences are generally quite small in lateral extent, on the order of 10 to 40 acres. Although existing fields are small in area, they are very productive; individual wells will probably make 300,000 to 500,000 barrels of oil. In the project area, hydrodynamic considerations are important. All the existing Tensleep fields have active water drives. In many cases, the reservoir pressure today is as it was when initially discovered. In areas of high structural complexity, such as the Lodge Grass-Crow Agency fault and the Lake Basin fault zone, significant structural closure may be necessary to trap oil because of the strong hydrodynamic influence exerted by the underlying Madison Formation aquifer.

  8. New Vitrinite Reflectance Data for the Bighorn Basin, North-Central Wyoming and South-Central Montana

    Science.gov (United States)

    Finn, Thomas M.; Pawlewicz, Mark J.

    2007-01-01

    Introduction The Bighorn Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that encompasses about 10,400 mi2 in north-central Wyoming and south-central Montana (fig. 1). Important conventional oil and gas resources have been discovered and produced from reservoirs ranging in age from Cambrian through Tertiary (Fox and Dolton, 1989, 1996a, b; De Bruin, 1993). In addition, a potential unconventional basin-centered gas accumulation may be present in Cretaceous reservoirs (Johnson and Finn, 1998; Johnson and others, 1999). The purpose of this report is to present new vitrinite reflectance data to be used in support of the U.S Geological Survey's assessment of undiscovered oil and gas resources of the Bighorn Basin. These new data supplement previously published data by Nuccio and Finn (1998), and Yin (1997), and lead to a better understanding and characterization of the thermal maturation and burial history of potential source rocks. Eighty-nine samples of Cretaceous and Tertiary strata (fig. 2) were collected and analyzed - 15 samples were from outcrops around the margins of the basin and 74 samples were well cuttings (fig. 1). Forty-one of the samples were shale, two were carbonaceous shale, and the remainder from coal. All samples were analyzed by vitrinite reflectance to determine levels of thermal maturation. Preparation of samples for reflectance analysis required (1) crushing the larger pieces into 0.25-to 1-mm pieces, (2) casting the pieces with epoxy in pre-cut and drilled plugs, and (3) curing the samples overnight. Subsequently, a four-step grinding and polishing process was implemented that included sanding with progressively finer sandpaper (60 and 600 grit) followed with a two-step polishing process (0.3 and 0.05 micron). Vitrinite reflectance measurements were determined at 500 X magnification using plane-polarized incident white light and a 546-nm monochromatic filter in immersion oil. For samples containing

  9. Watershed management

    Science.gov (United States)

    Watershed management is aimed at land and water resources, and is applied to an area of land that drains to a defined location along a stream or river. Watershed management aims to care for natural resources in a way that supports human needs for water, food, fiber, energy, and habitation, while sup...

  10. Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed.

    Science.gov (United States)

    Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

    2017-03-03

    In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.

  11. Ancient DNA reveals temporal population structure within the South-Central Andes area.

    Science.gov (United States)

    Russo, M Gabriela; Mendisco, Fanny; Avena, Sergio A; Crespo, Cristian M; Arencibia, Valeria; Dejean, Cristina B; Seldes, Verónica

    2018-04-01

    The main aim of this work was to contribute to the knowledge of pre-Hispanic genetic variation and population structure among the South-central Andes Area by studying individuals from Quebrada de Humahuaca, North-western (NW) Argentina. We analyzed 15 autosomal STRs in 19 individuals from several archaeological sites in Quebrada de Humahuaca, belonging to the Regional Developments Period (900-1430 AD). Compiling autosomal, mitochondrial, and Y-chromosome data, we evaluated population structure and differentiation among eight South-central Andean groups from the current territories of NW Argentina and Peru. Autosomal data revealed a structuring of the analyzed populations into two clusters which seemed to represent different temporalities in the Andean pre-Hispanic history: pre-Inca and Inca. All pre-Inca samples fell into the same cluster despite being from the two different territories of NW Argentina and Peru. Also, they were systematically differentiated from the Peruvian Inca group. These results were mostly confirmed by mitochondrial and Y-chromosome analyses. We mainly found a clearly different haplotype composition between clusters. Population structure in South America has been mostly studied on current native groups, mainly showing a west-to-east differentiation between the Andean and lowland regions. Here we demonstrated that genetic population differentiation preceded the European contact and might have been more complex than thought, being found within the South-central Andes Area. Moreover, divergence among temporally different populations might be reflecting socio-political changes occurred in the evermore complex pre-Hispanic Andean societies. © 2018 Wiley Periodicals, Inc.

  12. The rediscovery of Astragalus autranii (Fabaceae) on Mt Tomor, south central Albania

    DEFF Research Database (Denmark)

    Tan, Kit; Shuka, Lulezim; Gjeta, Ermelinda

    2015-01-01

    Astragalus autranii (Fabaceae) placed by Sytin & Podlech in a section of its own (A. sect. Baldaccia) was described from a single specimen in the Barbey-Boissier Herbarium at Geneva. Our observations show that its placement in A. sect. Hololeuce would also be appropriate. The species was first...... collected by Baldacci in 1892 on Mt Tomor in south central Albania and rediscovered by Markgraf at the locus classicus in June 1928. A complete and amended description of the species is here provided as corolla features were not available in the type material and the flower colour was incorrectly described...

  13. Palynological and iridium anomalies at Cretaceous-Tertiary boundary, south-central Saskatchewan

    Science.gov (United States)

    Nichols, D.J.; Jarzen, D.M.; Orth, C.J.; Oliver, P.Q.

    1986-01-01

    The Cretaceous-Tertiary boundary in south-central Saskatchewan is marked by coincident anomalies in abundance of iridium and fern spores at the extinction level of a suite of Cretaceous pollen taxa. Evidence of disruption of the terrestrial flora includes the fern-spore abundance anomaly and local extinction of as much as 30 percent of angiosperm species. The reorganized earliest Tertiary flora is made up largely of surviving species that assumed new roles of dominance. Persistence of climatically sensitive taxa across the boundary indicates that if paleoclimate was altered by the terminal Cretaceous event, it returned quickly to the pre-event condition.

  14. Spectra of the earthquake sequence February-March, 1981, in south-central Sweden

    OpenAIRE

    O. Kulhánek; T. van Eck; N. John; K. Meyer; Rutger Wahlström

    1983-01-01

    On February 13, 1981, a relatively strong earthquake occurred in the Lake Vanern region in south-central Sweden. The shock had a magnitude of M"SUB L" = 3.3 and was followed within three weeks by three aftershocks, with magnitudes 0.5 = or < M"SUB L" = or < 1.0. The focal mechanism solution of the main shock indicates reverse faulting with a strike in the N-S or NE-SW direction and a nearly horizontal compressional stress. The aftershocks were too small to yield data for a full mechanism solu...

  15. Delineation of the High Enthalpy Reservoirs of the Sierra Nevada Volcanic Geothermal System, South-Central Chile

    Science.gov (United States)

    Alam, M.; Muñoz, M.; Parada, M.

    2011-12-01

    Geothermal system associated with the Pleistocene-Holocene Sierra Nevada volcano (SNVGS) in the Araucanía Region of Chile has surface manifestations from the north-western flank of the volcano, up to Manzanar and Malalcahuello. Baños del Toro, located on the northwestern flank of the volcano, has numerous fumaroles and acid pools (acid sulfate waters, T=~90°C, pH=2.1, TDS=3080 mg/L); while Aguas de la Vaca, near the base of the volcano, has a bubbling spring (chloride-sulfate waters, T=~60°C, pH=7.0, TDS=950 mg/L). Five shallow (Geotermia) of the Ministry of Energy and Mining, Government of Chile.

  16. U.S. Department of the Interior South Central Climate Science Center

    Science.gov (United States)

    Shipp, Allison A.

    2012-01-01

    On September 14, 2009, the Secretary of the Interior signed a Secretarial Order (No. 3289) entitled, "Addressing the Impacts of Climate Change on America's Water, Land, and Other Natural and Cultural Resources." The Order effectively established the U.S. Department of the Interior (DOI) Climate Science Centers (CSCs) for the purpose of integrating DOI science and management expertise with similar contributions from our partners to provide information to support strategic adaptation and mitigation efforts on public and private lands across the United States and internationally. The South Central Climate Science Center (SC CSC) is supported by a consortium of partners that include The University of Oklahoma, Texas Tech University, Louisiana State University, The Chickasaw Nation, The Choctaw Nation of Oklahoma, Oklahoma State University, and the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory. Additionally, the SC CSC will collaborate with a number of other universities, State and federal agencies, and nongovernmental organizations (NGOs) with interests and expertise in climate science. The primary partners of the SC CSC are the Landscape Conservation Cooperatives (LCCs), which include the Desert, Eastern Tallgrass Prairie and Big Rivers, Great Plains, Gulf Coast Prairie, Gulf Coastal Plains and Ozarks, and Southern Rockies. CSC collaborations are focused on common science priorities that address priority partner needs, eliminate redundancies in science, share scientific information and findings, and expand understanding of climate change impacts in the south-central United States and Mexico.

  17. Lead in drinking water: sampling in primary schools and preschools in south central Kansas.

    Science.gov (United States)

    Massey, Anne R; Steele, Janet E

    2012-03-01

    Studies in Philadelphia, New York City, Houston, Washington, DC, and Greenville, North Carolina, have revealed high lead levels in drinking water. Unlike urban areas, lead levels in drinking water in suburban and rural areas have not been adequately studied. In the study described in this article, drinking water in primary schools and preschools in five suburban and rural south central Kansas towns was sampled to determine if any exceeded the U.S. Environmental Protection Agency (U.S. EPA) guidance level for schools and child care facilities of 20 parts per billion (ppb). The results showed a total of 32.1% of the samples had detectable lead levels and 3.6% exceeded the U.S. EPA guidance level for schools and child care providers of 20 ppb. These results indicate that about one-third of the drinking water consumed by children age six and under in the five suburban and rural south central Kansas towns studied has some lead contamination, exposing these children to both short-term and long-term health risks. The authors suggest a need for increased surveillance of children's drinking water in these facilities.

  18. A 600-year-long stratigraphic record of tsunamis in south-central Chile

    Science.gov (United States)

    Hong, Isabel; Dura, Tina; Ely, Lisa L.; Horton, Benajamin P.; Nelson, Alan R.; Cisternas, Marco; Nikitina, Daria; Wesson, Robert L.

    2017-01-01

    The stratigraphy within coastal river valleys in south-central Chile clarifies and extends the region’s history of large, earthquakes and accompanying tsunamis. Our site at Quidico (38.1°S, 73.3°W) is located in an overlap zone between ruptures of magnitude 8–9 earthquakes in 1960 and 2010, and, therefore, records tsunamis originating from subduction-zone ruptures north and south of the city of Concepción. Hand-dug pits and cores in a 3-m-thick sequence of freshwater peat in an abandoned meander (a little-examined depositional environment for tsunami deposits) and exposures along the Quidico River show five sand beds that extend as much as 1.2 km inland. Evidence for deposition of the beds by tsunamis includes tabular sand beds that are laterally extensive (>100 m), well sorted, fine upward, have sharp lower contacts, and contain diatom assemblages dominated by brackish and marine taxa. Using eyewitness accounts of tsunami inundation, 137Cs analyses, and 14C dating, we matched the upper four sand beds with historical tsunamis in 2010, 1960, 1835, and 1751. The oldest prehistoric bed dates to 1445–1490 CE and correlates with lacustrine and coastal records of similar-aged earthquakes and tsunamis in south-central Chile.

  19. Watershed District

    Data.gov (United States)

    Kansas Data Access and Support Center — Boundaries show on this map are derived from legal descriptions contained in petitions to the Kansas Secretary of State for the creation or extension of watershed...

  20. Historical and projected climate (1901–2050) and hydrologic response of karst aquifers, and species vulnerability in south-central Texas and western South Dakota

    Science.gov (United States)

    Stamm, John F.; Poteet, Mary F.; Symstad, Amy J.; Musgrove, MaryLynn; Long, Andrew J.; Mahler, Barbara J.; Norton, Parker A.

    2015-12-18

    Two karst aquifers, the Edwards aquifer in the Balcones Escarpment region of south-central Texas and the Madison aquifer in the Black Hills of western South Dakota, were evaluated for hydrologic response to projected climate change through 2050. Edwards aquifer sites include Barton Springs, the Bexar County Index Well, and Comal Springs. Madison aquifer sites include Spearfish Creek and Rhoads Fork Spring. Climate projections at sites were based on output from the Community Climate System Model of global climate, linked to the Weather Research and Forecasting (WRF) model of regional climate. The WRF model output was bias adjusted to match means for 1981–2010 from records at weather stations near Madison and Edwards aquifer sites, including Boerne, Texas, and Custer and Lead, South Dakota. Hydrologic response at spring and well sites was based on the Rainfall-Response Aquifer and Watershed Flow (RRAWFLOW) model. The WRF model climate projections for 2011–50 indicate a significant upward trend in annual air temperature for all three weather stations and a significant downward trend in annual precipitation for the Boerne weather station. Annual springflow simulated by the RRAWFLOW model had a significant downward trend for Edwards aquifer sites and no trend for Madison aquifer sites.

  1. Early development of the south Central American margin: mechanisms and tectonic implications

    Science.gov (United States)

    Buchs, D. M.; Baumgartner, P. O.; Arculus, R.; Montes, C.; Bayona, G.; Cardona, A.

    2012-04-01

    The south Central American margin forms the SW border of the Caribbean Plate on top of the subducting Cocos and Nazca Plates between Nicaragua and Colombia. New and previous tectonostratigraphic, age and geochemical results show that the forearc basement between south Costa Rica and east Panama is composed of autochthonous and accreted sequences that provide important constraints on the development of the south Central American margin, the evolution of the Caribbean Plate and the formation of an inter-American land bridge. Autochtonous sequences in the forearc include three tectonostratigraphic units that occur at a regional scale: (1) a Late Cretaceous oceanic plateau considered to represent an extension of the Caribbean Large Igneous Province (CLIP) at the base of the arc; (2) Late Campanian to Maastrichtian protoarc sequences that cover or intrude the oceanic plateau; and (3) Maastrichtian to Eocene sequences of a more mature volcanic arc that overlies or intrude preceding units. These units clearly indicate that subduction initiation along the margin and, thus, the birth of the Caribbean Plate occurred in the Campanian. Incipient subduction was possibly triggered or facilitated by contrasted lithospheric strength across the edge of the CLIP and collision between the CLIP and South America during westward migration of South America. Accreted sequences in the forearc include mostly Late Cretaceous to Eocene seamount fragments between south Costa Rica and west Panama, with additional Eocene to Miocene olistostromal and hemipelagic sediments in south Costa Rica. The age and tectonostratigraphic relationships of accreted sequences, autochtonous sequences, and overlying forearc slope sediment suggest that subduction erosion, punctuated by local seamount or sediment accretion was the dominant process controlling the evolution of the outer margin at least until the Miocene. A major tectonic event affected the margin in the Middle Eocene, which is indicated by a

  2. Evidence of shared bovine viral diarrhea infections between red deer and extensively raised cattle in south-central Spain.

    Science.gov (United States)

    Rodríguez-Prieto, Víctor; Kukielka, Deborah; Rivera-Arroyo, Belén; Martínez-López, Beatriz; de las Heras, Ana Isabel; Sánchez-Vizcaíno, José Manuel; Vicente, Joaquín

    2016-01-14

    Bovine viral diarrhea virus (BVDV) is a pestivirus that affects cattle production worldwide and that can infect other ungulates such as cervids and even wild boar (Sus scrofa). It is believed that domestic livestock can become infected through contact with wild animals, though it is known that infection can spread among wild animals in the absence of contact with livestock. Little is known about the sharing of BVDV infection between wild and domestic animals in the same habitat, which is important for designing eradication campaigns and preventing outbreaks, especially on hunting estates with high animal densities. We assessed the sharing of BVDV infections among hunted red deer, wild boar and cattle in south-central Spain. Sampled red deer (Cervus elaphus; n = 267) and wild boar (n = 52) were located on 19 hunting estates, and cattle (n = 180) were located on 18 nearby farms. We used ELISA kits for the serological screening, Taqman RT-PCR assay for the virus determination, and subsequent phylogenetic analysis for 17 RT-PCR positive sample amplicons. Fifty-two red deer (19.5%) and 82 cattle (45.6%) samples tested positive by ELISA. A high apparent prevalence (22.47%) was obtained for red deer, while only five cattle farms tested positive by RT-PCR. Conversely, no wild boar tested positive by both ELISA or RT-PCR. Eleven red deer (4.1%) tested positive by both ELISA and RT-PCR; these animals may have been sampled during the last phase of viremia, or they may represent previously exposed individuals infected by a different BVDV strain. The amplicons shared 92.7-100% identity and fell within the BVDV subgroup 1b, although nine of these (from four red deer and five cattle pools) formed a separate branch. This suggests that there might be a common BVDV infecting both cattle and red deer. Higher red deer abundance was significantly associated with greater risk that extensively raised cattle would test positive for BVDV by ELISA. Our findings suggest that BVDV

  3. Avian Influenza Virus Surveillance in South-Central Spain Using Fecal Samples of Aquatic Birds Foraging at Landfills

    Directory of Open Access Journals (Sweden)

    Andreia Bárbara

    2017-10-01

    Full Text Available Aquatic wild birds have been intensively studied to better understand their role in avian influenza virus (AIV maintenance and spread. To date, AIV surveillance has primarily focused on natural aquatic environments where different bird species aggregate and viral survival is enhanced. However, artificial habitats such as landfills are attracting substantial numbers of wild birds, AIV reservoir species included. The use of landfills as a predictable food source has significantly influenced population size, migratory traits, and feeding behavior of white storks (Ciconia ciconia and black-headed gulls (Chroicocephalus ridibundus among others. Considering the proximity of landfills to urban settlements and frequently poultry-farms, targeted monitoring of AIV in bird species that forage at landfills but are known to also frequent urban and agricultural habitats could be a useful means for monitoring of AIV, especially during periods of bird aggregation. During the wintering season 2014–2015, the prevalence of AIV in five avian species at two landfills in South-Central Spain was explored by rRT-PCR and species related temporal variation in AIV prevalence determined. We collected and tested 1,186 fresh fecal samples from white storks (N = 689, cattle egrets (Bubulcus ibis, N = 116 and mixed flocks of gulls (N = 381 as well as cloacal and oral swabs from five birds found dead. Seven samples contained AIV, five from gulls and one each from a stork and a cattle egret. Overall, AIV prevalence was 0.60%. No significant temporal variation was observed in AIV prevalence. Prevalence differed significantly among the sampled taxonomic groups, being highest in gulls (1.31%. H16N3 subtype was detected from a cattle egret and H11N9 subtype from a white stork, whereas gulls harbored both subtypes in addition to H11N3 subtype. H16 subtype detection in a cattle egret evidences its host range may not be restricted to gulls. Our results indicate that wild

  4. The Protective Effects of Adolescent Motherhood in South Central Appalachia: Salvation From Drugs and Emptiness.

    Science.gov (United States)

    Dalton, Elizabeth D

    2015-09-01

    This study qualitatively explored the meaning of teenage motherhood to young Appalachian mothers. Fourteen in-depth interviews at the homes of mothers between the ages of 18 and 22 from the South Central Appalachian region were conducted. Findings indicate that teenage motherhood is symbolically reproduced by filling a void and providing escape from the drug culture. Analysis of these findings indicates that the meaning of motherhood is characterized by salvation. This salvation is shaped by the emotional chasm that motherhood fills, as well as the protective barrier it provides between the mother and the surrounding drug culture. Implications of these findings might include a need to examine the protective effects of motherhood from negative sociocultural forces among other subcultures. Also, the pervasive drug culture that surrounds young people in Appalachia should be taken into consideration when shaping policy and interventions for teenage pregnancy prevention. © The Author(s) 2014.

  5. Factors affecting condom usage among college students in South Central Kentucky.

    Science.gov (United States)

    Kanekar, Amar; Sharma, Manoj

    The absence of consistent and correct usage of condoms increases the risk of sexually transmitted infections (STI) and HIV/AIDS. However, most studies done to date across the nation indicate a low usage of condoms among college students. This study identifies protective and risk factors associated with condom use among college students. The National College Health Assessment was administered to a random sample of students at a state comprehensive university in south central Kentucky. Findings revealed that among the sexually active students, approximately half never used condoms during vaginal intercourse. Further, among students engaging in oral sex, an alarmingly high proportion (95%) reported never using a condom during this act. These findings, along with differences noted in various subgroups (gender, housing, class standing), and other risk behaviors (alcohol, illicit drug use) are discussed.

  6. Multiethnicity, pluralism, and migration in the south central Andes: An alternate path to state expansion.

    Science.gov (United States)

    Goldstein, Paul S

    2015-07-28

    The south central Andes is known as a region of enduring multiethnic diversity, yet it is also the cradle of one the South America's first successful expansive-state societies. Social structures that encouraged the maintenance of separate identities among coexistent ethnic groups may explain this apparent contradiction. Although the early expansion of the Tiwanaku state (A.D. 600-1000) is often interpreted according to a centralized model derived from Old World precedents, recent archaeological research suggests a reappraisal of the socio-political organization of Tiwanaku civilization, both for the diversity of social entities within its core region and for the multiple agencies behind its wider program of agropastoral colonization. Tiwanaku's sociopolitical pluralism in both its homeland and colonies tempers some of archaeology's global assumptions about the predominant role of centralized institutions in archaic states.

  7. Modeling Prices for Sawtimber Stumpage in the South-Central United States

    Directory of Open Access Journals (Sweden)

    Rajan Parajuli

    2016-07-01

    Full Text Available The South-Central United States, which includes the states of Louisiana, Mississippi, Texas, and Arkansas, represents an important segment of the softwood sawtimber market. By using the Seemingly Unrelated Regression (SUR method to account for the linkage among the four contiguous timber markets, this study examines the dynamics of softwood sawtimber stumpage markets within the region. Based on quarterly data from 1981 to 2014, the findings reveal that both pulpwood and chip-and-saw (CNS prices have a positive influence on the Texas and Arkansas sawtimber markets. Moreover, Granger-causality tests suggest that unidirectional causality runs from pulpwood and CNS markets to the respective sawtimber market. Compared to the pre-financial crisis period, sawtimber prices in these four states are 9%–17% lower in the recent years.

  8. Monitoring the vegetation structure of south-central Etosha National Park using terrestrial photographs

    Directory of Open Access Journals (Sweden)

    M.H.T. Hipondoka

    2003-12-01

    Full Text Available In 1984, a ground-based, photographic library was initiated for monitoring the vegetation dynamics in Etosha National Park. Over 400 photographic points were selected. At these points, panchromatic photographs were taken at intervals of six years. This study was undertaken to assess the applicability of this terrestrial photographic library in characterising the dynamics of the vegetation structure in south-central Etosha National Park. The methods employed include field validation, visual photograph interpretations, spatial analysis, and aggregated two-dimensional tables. Results, though patchy in nature, show that the vegetation structure at 63 % of the sites covered remained either unchanged or increased over the 15-year study period. The patchiness of the photo points can be exploited and be treated as training sites for corresponding satellite image classifications to provide continuous ground coverage results.

  9. Watershed management in Myanmar

    International Nuclear Information System (INIS)

    Choi, K.S.

    1993-01-01

    Watershed degradation, watershed management, background of watershed management in Myanmar (condition of watershed, manpower), discussion and recommendation (proposed administrative structure, the need for watershed survey and planning, bottom-up approach) are emphasized. Watershed management, after all can be seen that it is the interphase between the forest, agriculture, soil, wildlife and the local communities

  10. Spatial and temporal interactions between livestock and wildlife in South Central Spain assessed by camera traps.

    Science.gov (United States)

    Kukielka, E; Barasona, J A; Cowie, C E; Drewe, J A; Gortazar, C; Cotarelo, I; Vicente, J

    2013-11-01

    The diversification of livestock farms into hunting estates in South Central Spain (SCS) may impede the success of Mycobacterium bovis eradication programmes by facilitating transmission between wildlife and livestock. In this observational study we aimed to provide information of relevance about the nature and frequency of interactions (observed visits to study points) between livestock (cattle and domestic pigs) and wildlife (wild boar and red deer). The study was conducted in an extensive cattle farm in SCS where the land is also used for game hunting. During a period of one year, camera traps (n=16) were placed at a priori risk points for interspecies interactions: water (natural and artificial troughs), food placed on the ground for baiting wildlife, and pasture. To define indirect interspecies interactions, a critical time window for M. bovis to survive in the environment was selected based on the literature. Results suggest that wildlife frequented food and pasture points more often than water points, and that the number of visits increased through the dry season, peaking during the acorn season (October-January) and the deer breeding season (June-July). Direct interactions were rare (n=10), as opposed to indirect interactions (n=8992). Wildlife-followed-by-livestock interactions (n=7714) occurred much more often than livestock-followed-by-wildlife (n=1278) and were frequent at water points (66% water points, 17% food, 17% pasture). Results also suggest that water points are a hotspot for indirect interactions and might therefore be a source of infection at the wildlife-livestock interface in the territory covered, particularly for M. bovis, as it is around water where the bacteria seem to survive the longest. Preventing aggregation and therefore reducing contact rates between domestic and wild animals especially at water points may be valuable for disease control in South Central Spain. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Land surface and atmospheric conditions associated with heat waves in the South Central United States

    Science.gov (United States)

    Lee, Eungul; Bieda, Rahama; Shanmugasundaram, Jothiganesh; Richter, Heather

    2017-04-01

    Exposure to extreme heat was reconstructed based on regional land-atmosphere processes from 1979 to 2010 in the South Central U.S. The study region surrounds the Chickasaw Nation (CN), a predominantly Native American population with a highly prevalent burden of climate-sensitive chronic diseases. Land surface and atmospheric conditions for summer heat waves were analyzed during spring (March-April-May, MAM) and summer (June-July-August, JJA) based on the Climate and Ocean: Variability, Predictability, and Change maximum temperature definition for heat wave frequency (HWF). The spatial-temporal pattern of HWF was determined using empirical orthogonal function (EOF) analysis and the corresponding principle component time series of the first EOF of HWF. Statistically significant analyses of observed conditions indicated that sensible heat increased and latent heat fluxes decreased with high HWF in the South Central U.S. The largest positive correlations of sensible heat flux to HWF and the largest negative correlations of latent heat flux to HWF were specifically observed over the CN. This is a significantly different energy transfer regime due to less available soil moisture during the antecedent MAM and JJA. The higher sensible heat from dry soil could cause significant warming from the near surface (> 2.0°C) to the lower troposphere (> 1.5°C), and accumulated boundary layer heat could induce the significant patterns of higher geopotential height and enhance anticyclonic circulations (negative vorticity anomaly) at the midtroposphere. Results suggested a positive land-atmosphere feedback associated with heat waves and called attention to the need for region-specific climate adaptation planning.

  12. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  13. Financial Performance of Mixed-Age Naturally Regenerated Loblolly-Hardwood Stands in the South Central United States

    Science.gov (United States)

    Ronald Raunikar; Joseph Buongiorno; Jeffrey P. Prestemon; Karen Lee Abt

    2000-01-01

    To estimate the financial performance of a natural mixed species and mixed-age management in the loblolly-pine forest type, we examined 991 FIA plots in the south central states. The plots were of the loblolly pine forest type, mixed-age, and had been regenerated naturally. We gauged the financial performance of each plot from the equivalent annual income (EAI)...

  14. Immigration and the Challenge of Education: A Social Drama Analysis in South Central Los Angeles. Education, Politics and Public Life

    Science.gov (United States)

    Jaramillo, Nathalia E.

    2012-01-01

    Part enthnograpy and part testimony, this book analyzes a school setting and community from the standpoint of a group of immigrant mothers (las madres) in South Central Los Angeles who were concerned about the education of their children and the violence in their communities. Written in both the first and third person, in Spanish and English, the…

  15. Challenges Facing Managers in Managing Conflict in Schools in the South and South Central Regions of Botswana

    Science.gov (United States)

    Morake, Nnior Machomi; Monobe, Ratau John; Dingwe, Stephonia

    2011-01-01

    The purpose of this study was to examine the challenges facing managers in managing conflict in schools of South and South Central Regions of Botswana. In this study, the schedule of interview was used to collect empirical data. A random sample of 50 school managers and deputy school managers was selected for interviews. Major findings of the…

  16. Wave-influenced deltaic sandstone bodies and offshore deposits in the Viking Formation, Hamilton Lake area, south-central Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Dafoe, L.T.; Gingras, M.K.; Pemberton, S.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences

    2010-06-15

    This analytical study incorporated sedimentological, ichnological and stratigraphic data to provide a framework for both deltaic and offshore deposition in the Hamilton Lake (HL) area in south-central Alberta. Fourty-one drill cores were logged within the area to conduct a comprehensive facies analysis of the Cretaceous Viking deposits at HL to refine the depositional history. The Viking deposits include a delta front, prodelta, upper offshore, lower offshore, shelf, slump and transgressive lag deposits. Various bioturbate textures proved useful in interpreting the paleoenvironment. Particular facies within HL strata contain physical and biogenic indicators of riverine discharge, and are considered to be deltaic in origin. This study focused on distinguishing between these deltaic deposits and strata reflecting normal-marine depositional conditions and relating facies within the stratigraphic framework. Four major bounding discontinuities and 2 major transgressive flooding surfaces separate units reflecting predominantly deltaic deposition, strictly offshore deposition, and mixed offshore and deltaic deposition. The implications of this study for petroleum exploration and development include better recognition of wave-influenced deltaic deposits in ancient successions. This paper presented a model that provided a better understanding of the nature of potential reservoirs in terms of lithology and morphology. In contrast to wave-dominated deltas or shoreface strata, sandy deposits in these wave-influenced systems are expected to contain higher proportions of mud, particularly mudstone laminae that reduce overall permeability between sandstone beds. 55 refs., 2 tabs., 15 figs.

  17. East Fork Watershed Cooperative: Toward better system-scale ...

    Science.gov (United States)

    The East Fork Watershed Cooperative is a group intent on understanding how to best manage water quality in a large mixed-use Midwestern watershed system. The system contains a reservoir that serves as a source of drinking water and is popular for water recreation. The reservoir is experience harmful algal blooms. The system including the reservoir has become a significant case study for EPA ORD research and development. The Cooperative includes affiliates from the USACE, the OHIO EPA, the USGS, the USDA, and local Soil and Water Conservation districts as well as utility operators and water quality protection offices. The presentation includes a description of the water quality monitoring and modeling program in the watershed, followed by the results of using the watershed model to estimate the costs associated with nutrient reduction to Harsha Lake, and then ends with an explanation of temporal changes observed for important factors controlling harmful algae in Harsha Lake and how this lake relates to other reservoirs in the Ohio River Basin. This presentation is an invited contribution to the Ohio River Basin Water Quality Workshop sponsored by the US ACE and the US EPA. The presentation describes the activities of the East Fork Watershed Cooperative and the knowledge it has gained to help better manage a case study watershed system over the last few years. The East Fork of the Little Miami River is the focal watershed. It is a significant tributary to the Lit

  18. Mobile LiDAR Measurement for Aerosol Investigation in South-Central Hebei, China

    Science.gov (United States)

    qin, kai; Wu, Lixin; Zheng, Yunhui; Wong Man, Sing; Wang, Runfeng; Hu, Mingyu; Lang, Hongmei; Wang, Luyao; Bai, Yang; Rao, Lanlan

    2016-04-01

    With the rapid industrialization and urbanization in China during the last decades, the increasing anthropogenic pollutant emissions have significantly caused serious air pollution problems which are adversely influencing public health. Hebei is one of the most air polluted provinces in China. In January 2013, an extremely severe and persistent haze episode with record-breaking PM2.5 outbreak affecting hundreds of millions of people occurred over eastern and northern China. During that haze episode, 7 of the top 10 most polluted cities in China were located in the Hebei Province according to the report of China's Ministry of Environmental Protection. To investigate and the spatial difference and to characterize the vertical distribution of aerosol in different regions of south-central Hebei, mobile measurements were carried out using a mini micro pulse LiDAR system (model: MiniMPL) in March 2014. The mobile LiDAR kit consisting of a MiniMPL, a vibration reduction mount, a power inverter, a Windows surface tablet and a GPS receiver were mounted in a car watching though the sunroof opening. For comparison, a fixed measurement using a traditional micro pulse LiDAR system (model: MPL-4B) was conducted simultaneously in Shijiazhuang, the capital of Hebei Province. The equipped car was driven from downtown Shijiazhuang by way of suburban and rural area to downtown Cangzhou, Handan, and Baoding respectively at almost stable speed around 100Km per hour along different routes which counted in total more than 1000Km. The results can be summarized as: 1) the spatial distribution of total aerosol optical depth along the measurement routes in south-central Hebei was controlled by local terrain and population in general, with high values in downtown and suburban in the plain areas, and low values in rural areas along Taihang mountain to the west and Yan mountain to the north; 2) obviously high AODs were obtained at roads crossing points, inside densely populated area and nearby

  19. Paleoseismic potential of sublacustrine landslide records in a high-seismicity setting (south-central Alaska)

    Science.gov (United States)

    Praet, Nore; Moernaut, Jasper; Van Daele, Maarten; Boes, Evelien; Haeussler, Peter J.; Strupler, Michael; Schmidt, Sabine; Loso, Michael G.; De Batist, Marc

    2017-01-01

    Sublacustrine landslide stratigraphy is considered useful for quantitative paleoseismology in low-seismicity settings. However, as the recharging of underwater slopes with sediments is one of the factors that governs the recurrence of slope failures, it is not clear if landslide deposits can provide continuous paleoseismic records in settings of frequent strong shaking. To test this, we selected three lakes in south-central Alaska that experienced a strong historical megathrust earthquake (the 1964 Mw9.2 Great Alaska Earthquake) and exhibit high sedimentation rates in their main basins (0.2 cm yr-1 -1.0 cm yr-1). We present high-resolution reflection seismic data (3.5 kHz) and radionuclide data from sediment cores in order to investigate factors that control the establishment of a reliable landslide record. Seismic stratigraphy analysis reveals the presence of several landslide deposits in the lacustrine sedimentary infill. Most of these landslide deposits can be attributed to specific landslide events, as multiple landslide deposits sourced from different lacustrine slopes occur on a single stratigraphic horizon. We identify numerous events in the lakes: Eklutna Lake proximal basin (14 events), Eklutna Lake distal basin (8 events), Skilak Lake (7 events) and Kenai Lake (7 events). The most recent event in each basin corresponds to the historic 1964 megathrust earthquake. All events are characterized by multiple landslide deposits, which hints at a regional trigger mechanism, such as an earthquake (the synchronicity criterion). This means that the landslide record in each basin represents a record of past seismic events. Based on extrapolation of sedimentation rates derived from radionuclide dating, we roughly estimate a mean recurrence interval in the Eklutna Lake proximal basin, Eklutna Lake distal basin, Skilak Lake and Kenai Lake, at ~ 250 yrs, ~ 450 yrs, ~ 900 yrs and ~ 450 yrs, respectively. This distinct difference in recording can be explained by variations

  20. Methane occurrence in groundwater of south-central New York State, 2012: summary of findings

    Science.gov (United States)

    Heisig, Paul M.; Scott, Tia-Marie

    2013-01-01

    A survey of methane in groundwater was undertaken to document methane occurrence on the basis of hydrogeologic setting within a glaciated 1,810-square-mile area of south-central New York that has not seen shale-gas resource development. The adjacent region in northeastern Pennsylvania has undergone shale-gas resource development from the Marcellus Shale. Well construction and subsurface data were required for each well sampled so that the local hydrogeologic setting could be classified. All wells were also at least 1 mile from any known gas well (active, exploratory, or abandoned). Sixty-six domestic wells and similar purposed supply wells were sampled during summer 2012. Field water-quality characteristics (pH, specific conductance, dissolved oxygen, and temperature) were measured at each well, and samples were collected and analyzed for dissolved gases, including methane and short-chain hydrocarbons. Carbon and hydrogen isotopic ratios of methane were measured in 21 samples that had at least 0.3 milligram per liter (mg/L) methane.

  1. Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska

    Directory of Open Access Journals (Sweden)

    Carlos Córdova

    2009-06-01

    Full Text Available The study of glacial landforms and deposits is important, as it isdifficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during Pleistocene times. This study investigates the genesis of little ice age glacial landforms present in Portage Glacier, South-Central Alaska. The present day moraine morphology and sedimentology in Portage Glacier valley reveals the presence of two types of till and moraines. The clast-rich sandy diamicton present on the 1852 moraine is interpreted to be a basal till indicating this feature is a pushmoraine representing an advance or a standstill position of Portage Glacier in 1852. The moderately sorted gray sandy boulder gravel present on the 1900 and 1922 moraines is interpreted to be an ice-marginal deposit (ablation till with a mixture of supraglacial and glaciofluvial sediments deposited by slumping and stream sortingprocesses. All of these features are interpreted to be ablation moraines representing glacier retreat and moraine building in 1900 and1922.

  2. Strain distribution and model for formation of eastern Umtanum Ridge anticline, south-central Washington

    Energy Technology Data Exchange (ETDEWEB)

    Price, E.H.

    1979-10-01

    Umtanum Ridge in south-central Washington is the topographic expression of a complex anticline within the Yakima Fold system in the Miocene Columbia River Basalt Group. The Yakima Fold system, which is partly contained within the Hanford Site, is an example of a layered basalt sequence folded near the surface of the earth. The Pasco Basin stratigraphic nomenclature is used in this repot. Rockwelll Hanford Operations, under contract to the US Department of Energy, is investigating the feasibility of therminal high-level nuclear waste storage in mined repositories in basalt beneath the Hanford Site. Because thereis essentially no basalt within the Site that has not been involved in some folding, any potential location for a repository will be either on the limbs or near the hinge zone of a Yakima Fold structure. Umtanum Ridge is the best exposed Yakima Fold structure in the vicinity of the Site for studying the nature and three-dimensional style of deformation of a multilayered basalt sequence. The structural geometry, distribution of strain within the Umtanum structure and deformational mechanisms of the Umtanum Ridge are discussed.

  3. Strain distribution and model for formation of eastern Umtanum Ridge anticline, south-central Washington

    International Nuclear Information System (INIS)

    Price, E.H.

    1979-10-01

    Umtanum Ridge in south-central Washington is the topographic expression of a complex anticline within the Yakima Fold system in the Miocene Columbia River Basalt Group. The Yakima Fold system, which is partly contained within the Hanford Site, is an example of a layered basalt sequence folded near the surface of the earth. The Pasco Basin stratigraphic nomenclature is used in this repot. Rockwelll Hanford Operations, under contract to the US Department of Energy, is investigating the feasibility of therminal high-level nuclear waste storage in mined repositories in basalt beneath the Hanford Site. Because thereis essentially no basalt within the Site that has not been involved in some folding, any potential location for a repository will be either on the limbs or near the hinge zone of a Yakima Fold structure. Umtanum Ridge is the best exposed Yakima Fold structure in the vicinity of the Site for studying the nature and three-dimensional style of deformation of a multilayered basalt sequence. The structural geometry, distribution of strain within the Umtanum structure and deformational mechanisms of the Umtanum Ridge are discussed

  4. Reduction of firewood consumption by households in south-central Chile associated with energy efficiency programs

    International Nuclear Information System (INIS)

    Schueftan, Alejandra; González, Alejandro D.

    2013-01-01

    Cities in the central-southern area of Chile face serious environmental pollution due to extensive use of firewood for heating. Low energy efficiency of constructions and cold climate increase the problem, which also affects native forests. The aims of this study are to characterize energy consumption in dwellings of this region, investigate the reduction potential, and study social and environmental consequences of high consumption of firewood. Actual energy consumption is studied with information from surveys, potential for reduction is modeled with software and other consequences are analyzed from previous studies. Results for the city of Valdivia show high firewood consumption per household, with a media bulk volume near 12 m 3 /year. Thermal regulations are softer compared with other countries. Moreover, around 85% of buildings were built before enforcing codes in 2007, and has almost no thermal protection. The reduction potential due to thermal improvements is found to be very high (62%) if buildings are refurbished to comply with the present Chilean Norm of 2007, but it reaches a 77% reduction if refurbished according to stricter foreign regulations. Therefore, an energy efficiency program strongly addressing existing buildings has the largest potential for reducing firewood use, and therefore mitigate environmental and health impacts. - Highlights: • High firewood consumption and environmental pollution in cities of south-central Chile. • High use of firewood due to inefficient constructions and soft thermal regulations. • Potential reduction of energy consumption up to 77% with more demanding regulations. • Policies should address building stock before thermal regulation, corresponding to 85%

  5. Bald eagle site management plan for the Hanford Site, south-central Washington

    International Nuclear Information System (INIS)

    Fitzner, R.F.; Weiss, S.G.

    1994-12-01

    The CERCLA remedial investigations of waste sites on the Hanford Site will involve lands containing or adjacent to a bald eagle nest, winter concentration areas, or communal night roost. Because these CERCLA investigations may affect bald eagles, the DOE has prepared this Bald Eagle Site Management Plan (BESMP). However, it is intended that this BESMP be used or updated so as to be also applicable to future activities that affect bald eagles on the Hanford Site. Bald eagles regularly use the US Department of Energy's (DOE) Hanford Site in south-central Washington State during winter months for roosting, perching, and foraging. Each of these activities requires buffer zones to protect eagles from human disturbances. Buffer zones developed in this plan follow recommended guidelines and are intended to be used in planning. If Hanford Site activities in the vicinity of identified bald eagle use areas are carried out in accordance with this plan, such actions are not likely to adversely affect the eagles or their habitat. Activities that may be exceptions will involve informal or formal (whichever is appropriate) consultation with the US Fish and Wildlife Service as required by the Endangered Species Act

  6. Paleozoogeography of the Wine Mouse (Akodon oenos & Late Holocene Paleoenvironments in South-Central Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Fernando Julián Fernández

    2011-02-01

    Full Text Available Cranial remains of the wine mouse (Akodon oenos are documented from an archaeological site in south-central Mendoza, Argentina (Agua de La Mula, 35º22' S, 68º15' W, which dates to the end of the late Holocene (1610 ± 60; 1260 ± 60; 1000 ± 50 C14 yr B.P.. The taxonomic status of this small rodent is currently being assessed, but these remains represent the first fossil record for the morphotaxon A. oenos. The species’ present distribution is restricted to a few records from Mendoza province. Analysis of the remains supports paleoenvironmental reconstruction using the small mammal assemblage recovered from this site. From the late Holocene into modernity temperature decreased and winter precipitation increased, resulting in advance of Patagonian steppe grading with altitude into Monte desert. Holocene climatic conditions may explain the relatively late human occupation of ecologically marginal environments in this region, which probably favored effective human occupation of the Payunia region at sites such as Agua de La Mula between 1600 and 1000 years B.P.

  7. An arid-adapted middle Pleistocene vertebrate fauna from south-central Australia.

    Science.gov (United States)

    Prideaux, Gavin J; Long, John A; Ayliffe, Linda K; Hellstrom, John C; Pillans, Brad; Boles, Walter E; Hutchinson, Mark N; Roberts, Richard G; Cupper, Matthew L; Arnold, Lee J; Devine, Paul D; Warburton, Natalie M

    2007-01-25

    How well the ecology, zoogeography and evolution of modern biotas is understood depends substantially on knowledge of the Pleistocene. Australia has one of the most distinctive, but least understood, Pleistocene faunas. Records from the western half of the continent are especially rare. Here we report on a diverse and exceptionally well preserved middle Pleistocene vertebrate assemblage from caves beneath the arid, treeless Nullarbor plain of south-central Australia. Many taxa are represented by whole skeletons, which together serve as a template for identifying fragmentary, hitherto indeterminate, remains collected previously from Pleistocene sites across southern Australia. A remarkable eight of the 23 Nullarbor kangaroos are new, including two tree-kangaroos. The diverse herbivore assemblage implies substantially greater floristic diversity than that of the modern shrub steppe, but all other faunal and stable-isotope data indicate that the climate was very similar to today. Because the 21 Nullarbor species that did not survive the Pleistocene were well adapted to dry conditions, climate change (specifically, increased aridity) is unlikely to have been significant in their extinction.

  8. Greenhouse gas fluxes of a shallow lake in south-central North Dakota, USA

    Science.gov (United States)

    Tangen, Brian; Finocchiaro, Raymond; Gleason, Robert A.; Dahl, Charles F.

    2016-01-01

    Greenhouse gas (GHG) fluxes of aquatic ecosystems in the northern Great Plains of the U.S. represent a significant data gap. Consequently, a 3-year study was conducted in south-central North Dakota, USA, to provide an initial estimate of GHG fluxes from a large, shallow lake. Mean GHG fluxes were 0.02 g carbon dioxide (CO2) m−2 h−1, 0.0009 g methane (CH4) m−2 h−1, and 0.0005 mg nitrous oxide (N2O) m−2 h−1. Fluxes of CO2 and CH4 displayed temporal and spatial variability which is characteristic of aquatic ecosystems, while fluxes of N2O were consistently low throughout the study. Comparisons between results of this study and published values suggest that mean daily fluxes of CO2, CH4, and N2O fromLong Lakewere low, particularly when compared to the well-studied prairie pothole wetlands of the region. Similarly, cumulative seasonal CH4 fluxes, which ranged from 2.68–7.58 g CH4 m−2, were relatively low compared to other wetland systems of North America. The observed variability among aquatic ecosystems underscores the need for further research.

  9. Ground beetles (Coleoptera, Carabidae of the Hanford Nuclear Site in south-central Washington State

    Directory of Open Access Journals (Sweden)

    Chris Looney

    2014-04-01

    Full Text Available In this paper we report on ground beetles (Coleoptera: Carabidae collected from the Hanford Nuclear Reservation and Hanford National Monument (together the Hanford Site, which is located in south-central Washington State. The Site is a relatively undisturbed relict of the shrub-steppe habitat present throughout much of the western Columbia Basin before the westward expansion of the United States. Species, localities, months of capture, and capture method are reported for field work conducted between 1994 and 2002. Most species were collected using pitfall traps, although other capture methods were employed. Trapping results indicate the Hanford Site supports a diverse ground beetle community, with over 90% of the 92 species captured native to North America. Four species collected during the study period are newly recorded for Washington State: Bembidion diligens Casey, Calosoma obsoletum Say, Pseudaptinus rufulus (LeConte, and Stenolophus lineola (Fabricius. Based on these data, the Site maintains a diverse ground beetle fauna and, due to its size and diversity of habitats, is an important repository of shrub-steppe biodiversity.

  10. Ground beetles (Coleoptera, Carabidae) of the Hanford Nuclear Site in south-central Washington State.

    Science.gov (United States)

    Looney, Chris; Zack, Richard S; Labonte, James R

    2014-01-01

    Carabidae) collected from the Hanford Nuclear Reservation and Hanford National Monument (together the Hanford Site), which is located in south-central Washington State. The Site is a relatively undisturbed relict of the shrub-steppe habitat present throughout much of the western Columbia Basin before the westward expansion of the United States. Species, localities, months of capture, and capture method are reported for field work conducted between 1994 and 2002. Most species were collected using pitfall traps, although other capture methods were employed. Trapping results indicate the Hanford Site supports a diverse ground beetle community, with over 90% of the 92 species captured native to North America. Four species collected during the study period are newly recorded for Washington State: Bembidion diligens Casey, Calosoma obsoletum Say, Pseudaptinus rufulus (LeConte), and Stenolophus lineola (Fabricius). Based on these data, the Site maintains a diverse ground beetle fauna and, due to its size and diversity of habitats, is an important repository of shrub-steppe biodiversity.

  11. Modeling water quality, temperature, and flow in Link River, south-central Oregon

    Science.gov (United States)

    Sullivan, Annett B.; Rounds, Stewart A.

    2016-09-09

    The 2.1-km (1.3-mi) Link River connects Upper Klamath Lake to the Klamath River in south-central Oregon. A CE-QUAL-W2 flow and water-quality model of Link River was developed to provide a connection between an existing model of the upper Klamath River and any existing or future models of Upper Klamath Lake. Water-quality sampling at six locations in Link River was done during 2013–15 to support model development and to provide a better understanding of instream biogeochemical processes. The short reach and high velocities in Link River resulted in fast travel times and limited water-quality transformations, except for dissolved oxygen. Reaeration through the reach, especially at the falls in Link River, was particularly important in moderating dissolved oxygen concentrations that at times entered the reach at Link River Dam with marked supersaturation or subsaturation. This reaeration resulted in concentrations closer to saturation downstream at the mouth of Link River.

  12. Cave-dwelling bats (Mammalia: Chiroptera and conservation concerns in South central Mindanao, Philippines

    Directory of Open Access Journals (Sweden)

    Krizler C. Tanalgo

    2015-12-01

    Full Text Available The stable microclimate in caves provides a relatively constant habitat for many bat species in the Philippines, but human encroachment continues to disrupt this habitat and imperil many of the species roosting in the caves.  In South central Mindanao, the diversity and conservation status of cave bats remain undocumented and unexplored.  We employed mist-netting to capture bats from five different caves within the town of Kabacan, northern Cotabato, Philippines.  A total of 14 bat species were identified including the Philippine endemics Hipposideros pygmaeus and Ptenochirus jagori and the threatened Megaerops wetmorei. However, despite the declining conservation status of the bats, local disturbance such as bat hunting for bush meat and unregulated tourism are currently taking place in the caves.  Large species such as Eonycteris spelaea and Rousettus amplexicaudatus are killed almost every day for food and trade.  Therefore, the high species richness, and the presence of endemic and threatened species coupled with the occurrence of anthropogenic disturbances in caves suggests the need for an urgent and effective conservation intervention involving the local government and public community. 

  13. Regional and Seasonal Diet of the Western Burrowing Owl in South-Central Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

    2009-04-01

    We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats (Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.

  14. A preliminary evaluation of regional ground-water flow in south-central Washington

    Science.gov (United States)

    La Sala, A. M.; Doty, G.C.; Pearson, F.J.

    1973-01-01

    The characteristics of regional ground-water flow were investigated in a 4,500-square-mile region of south-central Washington, centered on the U.S. Atomic Energy Commission Hanford Reservation. The investigation is part of the Commission's feasibility study on storing high-level radioactive waste in chambers mined in basaltic rocks at a. depth of about 3,000 feet or more below the surface. Ground-water flow., on a regional scale, occurs principally in the basalt and-in interbedded sediments of the Columbia River Group, and is controlled by topography, the structure of the basalt, and the large streams--the Columbia, Snake, and Yakima Rivers. The ground water beneath the main part of the Hanford Reservation, south and west of the Columbia River, inures southeastward from recharge areas in the uplands, including Cold Creek and Dry Creek valleys, and ultimately discharges to the Columbia River south of the reservation: East and southeast of the Columbia River, ground water flows generally southwestward and discharges to the River. The Yakima River valley contains a distinct flow system in which movement is toward the Yakima River from the topographic divides. A large southward-flowing ground-water system beneath the southern flank of the Horse Heaven Hills discharges to the Columbia River in the westward-trending reach downstream from Wallula Gap.

  15. Integrated numerical modeling for basin-wide water management: The case of the Rattlesnake Creek basin in south-central Kansas

    Science.gov (United States)

    Sophocleous, M.A.; Koelliker, J.K.; Govindaraju, R.S.; Birdie, T.; Ramireddygari, S.R.; Perkins, S.P.

    1999-01-01

    The objective of this article is to develop and implement a comprehensive computer model that is capable of simulating the surface-water, ground-water, and stream-aquifer interactions on a continuous basis for the Rattlesnake Creek basin in south-central Kansas. The model is to be used as a tool for evaluating long-term water-management strategies. The agriculturally-based watershed model SWAT and the ground-water model MODFLOW with stream-aquifer interaction routines, suitably modified, were linked into a comprehensive basin model known as SWATMOD. The hydrologic response unit concept was implemented to overcome the quasi-lumped nature of SWAT and represent the heterogeneity within each subbasin of the basin model. A graphical user-interface and a decision support system were also developed to evaluate scenarios involving manipulation of water fights and agricultural land uses on stream-aquifer system response. An extensive sensitivity analysis on model parameters was conducted, and model limitations and parameter uncertainties were emphasized. A combination of trial-and-error and inverse modeling techniques were employed to calibrate the model against multiple calibration targets of measured ground-water levels, streamflows, and reported irrigation amounts. The split-sample technique was employed for corroborating the calibrated model. The model was run for a 40 y historical simulation period, and a 40 y prediction period. A number of hypothetical management scenarios involving reductions and variations in withdrawal rates and patterns were simulated. The SWATMOD model was developed as a hydrologically rational low-flow model for analyzing, in a user-friendly manner, the conditions in the basin when there is a shortage of water.

  16. Exploring an innovative watershed management approach: From feasibility to sustainability

    International Nuclear Information System (INIS)

    Said, A.; Sehlke, G.; Stevens, D.K.; Sorensen, D.; Walker, W.; Hardy, T.; Glover, T.

    2006-01-01

    Watershed management is dedicated to solving watershed problems on a sustainable basis. Managing watershed development on a sustainable basis usually entails a balance between the needs of humans and nature, both in the present and in the future. From a watershed or water resources development basis, these problems can be classified into five general categories: lack of water quantity, deterioration in water quality, ecological impacts, weak public participation, and weak economic value. The first three categories can be combined to make up physical sustainability while the last two categories can be defined as social and economic sustainability. Therefore, integrated watershed management should be designed to achieve physical sustainability utilizing, to the greatest extent possible, public participation in an economically viable manner. This study demonstrates an innovative approach using scientific, social, and motivational feasibilities that can be used to improve watershed management. Scientific feasibility is tied to the nature of environmental problems and the scientific means to solve them. Social feasibility is associated with public participation. Motivational feasibility is related to economic stimulation for the stakeholders to take actions. The ecological impacts, lack of water quantity and deterioration in water quality are problems that need scientific means in order to improve watershed health. However, the implementation of these means is typically not achievable without the right public participation. In addition, public participation is typically accelerated by economic motivation for the stakeholders to use the resources in a manner that improves watershed health. The Big Lost River in south-central Idaho has been used as an illustration for implementing scientific, social and motivational feasibilities and in a manner that can achieve sustainability relative to water resources management. However, the same approach can be used elsewhere after

  17. Greybull Sandstone Petroleum Potential on the Crow Indian Reservation, South-Central Montana

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, David A.

    2002-05-13

    The focus of this project was to explore for stratigraphic traps that may be present in valley-fill sandstone at the top of the Lower Cretaceous Kootenai Formation. This sandstone interval, generally known as the Greybull Sandstone, has been identified along the western edge of the reservation and is a known oil and gas reservoir in the surrounding region. The Greybull Sandstone was chosen as the focus of this research because it is an excellent, well-documented, productive reservoir in adjacent areas, such as Elk Basin; Mosser Dome field, a few miles northwest of the reservation; and several other oil and gas fields in the northern portion of the Bighorn Basin.

  18. Estimation of Bank Erosion Due To Reservoir Operation in Cascade (Case Study: Citarum Cascade Reservoir

    Directory of Open Access Journals (Sweden)

    Sri Legowo

    2009-11-01

    Full Text Available Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP.The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir.Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008.

  19. PROFILE: Management of Sedimentation in Tropical Watersheds.

    Science.gov (United States)

    NAGLE; FAHEY; LASSOIE

    1999-05-01

    / The sedimentation of reservoirs is a serious problem throughout the tropics, yet most attempts to control sedimentation in large river basins have not been very successful. Reliable information on erosion rates and sources of sediments has been lacking. In regions where geologically unstable terrain combines with high rainfall, natural erosion rates might be so high that the effects of human activity are limited. Estimates of natural erosion in these situations often have been poor because of the episodic nature of most erosion during large storms and because mass-wasting may supply much of the sediment. The predominance of mass-wasting in some watersheds can result in an unexpectedly high ratio of bedload to suspended load, shifting sedimentation to "live" rather than "dead" storage within reservoirs. Furthermore, the inappropriate use of the Universal Soil Loss Equation to assess the effectiveness of erosion control measures has led to inaccurate estimates of the sediment reduction benefits that could accrue to watershed treatment efforts. Although reducing erosion from cultivated areas is desirable for other reasons, efforts aimed at reducing reservoir sedimentation by controlling agricultural sources of erosion may have limited benefits if the principal sources are of natural origin or are associated with construction of the dams and reservoirs and with rural roads and trails. Finally, the most appropriate locations for watershed rehabilitation depend on the magnitude of temporary storage of colluvium and alluvium within the river basin: Where storage volume is large and residence time of sediment very long, reducing agricultural erosion may have limited impacts on sedimentation within the expected life of a reservoir. Systematic development and analysis of sediment budgets for representative watersheds is needed to address these limitations and thereby improve both the planning of river basin development schemes and the allocation of resources towards

  20. Concentrations of selected pharmaceuticals and antibiotics in south-central Pennsylvania waters, March through September 2006

    Science.gov (United States)

    Loper, Connie A.; Crawford, J. Kent; Otto, Kim L.; Manning, Rhonda L.; Meyer, Michael T.; Furlong, Edward T.

    2007-01-01

    This report presents environmental and quality-control data from analyses of 15 pharmaceutical and 31 antibiotic compounds in water samples from streams and wells in south-central Pennsylvania. The analyses are part of a study by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Environmental Protection (PADEP) to define concentrations of selected emerging contaminants in streams and well water in Pennsylvania. Sampling was conducted at 11 stream sites and at 6 wells in 9 counties of south-central Pennsylvania. Five of the streams received municipal wastewater and 6 of the streams received runoff from agricultural areas dominated by animal-feeding operations. For all 11 streams, samples were collected at locations upstream and downstream of the municipal effluents or animal-feeding operations. All six wells were in agricultural settings. A total of 120 environmental samples and 21 quality-control samples were analyzed for the study. Samples were collected at each site in March/April, May, July, and September 2006 to obtain information on changes in concentration that could be related to seasonal use of compounds.For streams, 13 pharmaceuticals and 11 antibiotics were detected at least 1 time. Detections included analytical results that were estimated or above the minimum reporting limits. Seventy-eight percent of all detections were analyzed in samples collected downstream from municipal-wastewater effluents. For streams receiving wastewater effluents, the pharmaceuticals caffeine and para-xanthine (a degradation product of caffeine) had the greatest concentrations, 4.75 μg/L (micrograms per liter) and 0.853 μg/L, respectively. Other pharmaceuticals and their respective maximum concentrations were carbamazepine (0.516 μg/L) and ibuprofen (0.277 μg/L). For streams receiving wastewater effluents, the antibiotic azithromycin had the greatest concentration (1.65 μg/L), followed by sulfamethoxazole (1.34 μg/L), ofloxacin (0.329

  1. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. IV. - October of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Garcia A, J.; Rodriguez A, F.

    2002-01-01

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  2. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. II.- August of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Rodriguez A, F.; Garcia A, J.

    2001-12-01

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  3. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. III.- September of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Rodriguez A, F.; Garcia A, J.

    2001-12-01

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  4. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. V. - November of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Garcia A, J.; Rodriguez A, F.

    2002-01-01

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  5. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. I. - July of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.

    2001-09-01

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  6. Stratigraphy and depositional environments of Catahoula Formation sandstones and associated facies in south-central Mississippi

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, C.P. (Univ. of Southern Mississippi, Hattiesburg (USA)); Day, L.A. (Geraghty and Miller, Baton Rouge, LA (USA))

    1990-09-01

    Surface and subsurface studies of the Catahoula Formation in a seven county area of south-central Mississippi have revealed major problems and misconceptions regarding Neogene stratigraphy and geological mapping in this part of the Gulf basin. The results of these investigations show that the traditional stratigraphic subdivisions of the up-dip Neogene section in Mississippi are invalid, and that the fundamental criteria for defining rock stratigraphic units at the formation rank are nonexistent. Although the base of the Neogene section is reasonably well defined by virtue of its relatively continuous contact with the Bucatunna Formation (Oligocene Vicksburg Group), a mappable bounding sequence above the Catahoula-Bucatunna Formation contact does not exist in the study area. An overall fine-grained interval above the Catahoula Formation appears to wedge out before reaching outcrop. Hence, differentiation between up-dip sandy gravels of the Catahoula and similar facies of the Citronelle Formation is difficult. Further complicating the problem of stratigraphic unit discrimination is the discovery of sandy gravels within the Hattiesburg Formation interval. A subsurface analysis in this study area revealed that the Catahoula Formation, as defined by Day, attains a thickness of 625 ft and has a rough three-tiered stratigraphy: (a) a basal unit composed of sands and subordinate fine-grained facies; (b) a relatively fine-grained middle unit composed of silts and clays with recurrent, discontinuous, sand bodies; and (c) an upper unit composed largely of sand and gravels. This study confirmed that most of these sediments are the product of fluvial channel and associated floodplain deposition. However, in the basal unit deltaic facies appear to be preserved on outcrop in Smith County and perhaps in a mild structural depression in the southwest portion of the study area.

  7. Moisture Concentration Variation of Silages Produced on Commercial Farms in the South-Central USA

    Directory of Open Access Journals (Sweden)

    K. J. Han

    2014-10-01

    Full Text Available Preservation of forage crops as silage offers opportunity to avoid the high risk of rain-damaged hay in the humid south-central USA. Recent developments with baled silage or baleage make silage a less expensive option than typical chopped silage. Silage has been important in the region primarily for dairy production, but baleage has become an option for the more extensive beef cattle industry in the region. Silage samples submitted to the Louisiana State University Agricultural Center Forage Quality Lab from 2006 through 2013 were assessed for dry matter (DM and forage nutritive characteristics of chopped silage and baleage of the different forage types from commercial farms primarily in Louisiana and Mississippi. Of the 1,308 silage samples submitted, 1,065 were annual ryegrass (AR with small grains (SG, the warm-season annual (WA grasses, sorghums and pearl millet, and the warm-season perennial (WP grasses, bermudagrass and bahiagrass, providing the remaining samples. Concentration of DM was used to indicate an effective ensiling opportunity, and AR silage was more frequently within the target DM range than was the WA forage group. The AR samples also indicated a high-quality forage with average crude protein (CP of 130 g/kg and total digestible nutrient (TDN near 600 g/kg. The cooler winter weather at harvest apparently complicated harvest of SG silage with chopped SG silage lower in both CP and TDN (104 and 553 g/kg, respectively than either AR silage or baleage of SG (137 and 624 g/kg for CP and TDN, respectively. The hot, humid summer weather along with large stems and large forage quantities of the WA grasses and the inherently higher fiber concentration of WP grasses at harvest stage indicate that preservation of these forage types as silage will be challenging, although successful commercial silage samples of each forage type and preservation approach were included among samples of silages produced in the region.

  8. Land subsidence and earth fissures in south-central and southern Arizona, USA

    Science.gov (United States)

    Conway, Brian D.

    2016-05-01

    Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.

  9. Forearc uplift rates deduced from sediment cores of two coastal lakes in south-central Chile

    Science.gov (United States)

    Stefer, Susanne; Moernaut, Jasper; Melnick, Daniel; Echtler, Helmut P.; Arz, Helge W.; Lamy, Frank; De Batist, Marc; Oncken, O.; Haug, Gerald H.

    2010-11-01

    The present paper introduces a new approach for deriving information about local forearc tectonics and related uplift rates based on the study of lake sediments. We investigated two coastal lakes at the south-central Chile margin, lakes Lanalhue and Lleu Lleu, located south of the Arauco Peninsula (38°S). Both lakes developed within the valleys of ancient rivers that once drained to the Pacific Ocean, being subsequently dammed by rising sills in the late Pleistocene/early Holocene. Seismic profiling and sedimentological analyses of cores from both lakes revealed similar successions consisting of marine to brackish sediments covered by lacustrine deposits. Radiocarbon dating indicates that the marine-lacustrine transition occurred at 8 ka and 8.15 ka, respectively. The correlation of this transition with global sea-level curves allowed the calculation of local uplift rates for the Holocene. Uplift rates for the lake basins amount to 0.42 ± 0.71 and 0.49 ± 0.44 mm/a, respectively, which are consistent with rates determined from a late Pleistocene marine terrace in the area. However, conspicuously higher, though likely transient, vertical movements at 8.83 ± 2.7 mm/a and 11.36 ±1.77 mm/a, respectively, were calculated for the sills that block both lakes nowadays. These barriers are interpreted to be the surface expression of a blind reverse fault associated to the Morguilla fault system, a seismically-active structure that controls uplift and folding along the adjacent Arauco Peninsula.

  10. Active deformation processes across a megathrust-segment boundary, south-central Chile

    Science.gov (United States)

    Moreno, M. S.; Klotz, J.; Melnick, D.; Bolte, J.; Echtler, H.; Bataille, K.

    2009-04-01

    The south-central Chile margin is an active plate boundary where a variety of tectonic processes, including postseismic mantle relaxation, interseismic strain accumulation, sliver motions and crustal faulting are documented. GPS data and finite-element models with complex geometries are presented to gain insight into the active deformation in the vicinity of two megathrust-earthquake segments: the Valdivia and Concepción rupture zones. GPS vectors are heterogeneously distributed in two domains that follow the megathrust segments. Models which simulate only interseismic locking on the plate interface and postseismic relaxation after an uniform coseismic slip during the 1960 Valdivia earthquake (Mw=9.5) not fully reproduce the observed surface deformation. In order to distinguish between the main processes producing the regional-scale heterogeneity of surface velocities, we model: (1) the postseismic viscoelastic deformation induced by a non-uniform coseismic slip distribution, (2) the interseismic kinematic coupling, and (3) the interseismic effect of a crustal fault rooted in the plate interface. We find that interseismic locked asperities are spatially coincident with the historic earthquake rupture zones, which are separated by a sharp boundary of low (~ 50%) kinematic coupling. A regional pattern of clockwise rotations arise from postseismic mantle rebound at the overlap area of the rupture zones and extend over a broad segment between the forearc and the back-arc. Locally, counterclockwise block rotation is observed in a limited area south of the Lanalhue fault, and may be related to transpression at the northern leading edge of a forearc sliver. In the Concepción domain, models that include a dextral-reverse crustal fault better reproduce the GPS observations. Our study suggests that upper-plate crustal faults in addition to earthquake-cycle transients exert an important control on deformation processes at megathrust-segment boundaries.

  11. Risk across disciplines: An interdisciplinary examination of water and drought risk in South-Central Oklahoma

    Science.gov (United States)

    Lazrus, H.; Paimazumder, D.; Towler, E.; McPherson, R. A.

    2013-12-01

    Drought is a challenge faced by communities across the United States, exacerbated by growing demands on water resources and climate variability and change. The Arbuckle-Simpson Aquifer (ASA) in south-central Oklahoma, situated in the heart of the Chickasaw Nation, is the state's only sole-source groundwater basin and sustains the Blue River, the state's only free-flowing river. The recent comprehensive hydrological studies of the aquifer indicate the need for sustainable management of the amount of water extracted. However, the question of how to deal with that management in the face of increasing drought vulnerability, diverse demands, and climate variability and change remains. Water management carries a further imperative to be inclusive of tribal and non-tribal interests. To examine this question, we are conducting an investigation of drought risk from multiple disciplines. Anthropological data comes from stakeholder interviews that were designed to investigate conflict over water management by understanding how people perceive risk differently based on different opinions about the structure of the resource, varying levels of trust in authorities, and unequal access to resources. . The Cultural Theory of Risk is used to explain how people view risks as part of their worldviews and why people who hold different worldviews disagree about risks associated with water availability. Meteorological analyses of longitudinal data indicate periods of drought that are noted in stakeholder interviews. Analysis of stream gauge data investigates the influence of climate variability on local hydrologic impacts, such as changing groundwater levels and streamflows, that are relevant to planning and management decisions in the ASA. Quantitative assessment of future drought risk and associated uncertainty and their effect on type and scale of future economic and social impacts are achieved by combining elements of statistical and dynamical downscaling to improve predictions of

  12. Chemical stratigraphy of Grande Ronde Basalt, Pasco Basin, south-central Washington

    International Nuclear Information System (INIS)

    Long, P.E.; Ledgerwood, R.K.; Myers, C.W.; Reidel, S.P.; Landon, R.D.; Hooper, P.R.

    1980-02-01

    Grande Ronde Basalt in the Pasco Basin, south-central Washington, can be subdivided into three chemical types and two chemical subtypes based on x-ray fluorescence major element analysis of samples from seven deep core holes and three surface sections. These chemical types are: (1) high-Mg Grande Ronde chemical type; (2) low-Mg Grande Ronde chemical type; (3) low-K (very high-Mg.) Grande Ronde chemical type; and (4) Umtanum Grande Ronde chemical subtype. A possible fifth subdivision is the McCoy Canyon Grande Ronde chemical subtype. The Umtanum and the McCoy Canyon subtypes are both single flows which belong to the low Mg and high-Mg chemical types, respectively. These subdivisions are all distinguished on a plot of MgO versus TiO 2 and/or MgO versus P 2 O 5 , but other major and minor elements, as well as trace elements, also reflect consistent chemical differences between the chemical types. Identification of these chemical types in the Pasco Basin subsurface shows that the high-Mg and low-Mg chemical types are ubiquitous, but the low-K chemical type is limited to the central, southern, and eastern parts of the basin. The Umtanum chemical subtype is present throughout the Pasco Basin subsurface, although it thins in the northeastern part of the basin and is apparently absent from surface exposures 40 kilometers (25 miles) north of the basin. The McCoy Canyon chemical subtype is also present throughout the basin

  13. Prevalence of malaria infection in Butajira area, south-central Ethiopia

    Directory of Open Access Journals (Sweden)

    Woyessa Adugna

    2012-03-01

    Full Text Available Abstract Background In 2005, the Ethiopian government launched a massive expansion of the malaria prevention and control programme. The programme was aimed mainly at the reduction of malaria in populations living below 2,000 m above sea level. Global warming has been implicated in the increase in the prevalence of malaria in the highlands. However, there is still a paucity of information on the occurrence of malaria at higher altitudes. The objective of this study was to estimate malaria prevalence in highland areas of south-central Ethiopia, designated as the Butajira area. Methods Using a multi-stage sampling technique, 750 households were selected. All consenting family members were examined for malaria parasites in thick and thin blood smears. The assessment was repeated six times for two years (October 2008 to June 2010. Results In total, 19,207 persons were examined in the six surveys. From those tested, 178 slides were positive for malaria, of which 154 (86.5% were positive for Plasmodium vivax and 22 (12.4% for Plasmodium falciparum; the remaining two (1.1% showed mixed infections of Plasmodium falciparum and Plasmodium vivax. The incidence of malaria was higher after the main rainy season, both in lower lying and in highland areas. The incidence in the highlands was low and similar for all age groups, whereas in the lowlands, malaria occurred mostly in those of one to nine years of age. Conclusion This study documented a low prevalence of malaria that varied with season and altitudinal zone in a highland-fringe area of Ethiopia. Most of the malaria infections were attributable to Plasmodium vivax.

  14. Subduction zone slip variability during the last millennium, south-central Chile

    Science.gov (United States)

    Dura, Tina; Horton, Benjamin P.; Cisternas, Marco; Ely, Lisa L.; Hong, Isabel; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica E.; Parnell, Andrew C.; Nikitina, Daria

    2017-11-01

    The Arauco Peninsula (37°-38°S) in south-central Chile has been proposed as a possible barrier to the along-strike propagation of megathrust ruptures, separating historical earthquakes to the south (1960 AD 1837, 1737, and 1575) and north (2010 AD, 1835, 1751, 1657, and 1570) of the peninsula. However, the 2010 (Mw 8.8) earthquake propagated into the Arauco Peninsula, re-rupturing part of the megathrust that had ruptured only 50 years earlier during the largest subduction zone earthquake in the instrumental record (Mw 9.5). To better understand long-term slip variability in the Arauco Peninsula region, we analyzed four coastal sedimentary sections from two sites (Tirúa, 38.3°S and Quidico, 38.1°S) located within the overlap of the 2010 and 1960 ruptures to reconstruct a ∼600-year record of coseismic land-level change and tsunami inundation. Stratigraphic, lithologic, and diatom results show variable coseismic land-level change coincident with tsunami inundation of the Tirúa and Quidico marshes that is consistent with regional historical accounts of coseismic subsidence during earthquakes along the Valdivia portion of the subduction zone (1960 AD and 1575) and coseismic uplift during earthquakes along the Maule portion of the subduction zone (2010 AD, 1835, 1751). In addition, we document variable coseismic land-level change associated with three new prehistoric earthquakes and accompanying tsunamis in 1470-1570 AD, 1425-1455, and 270-410. The mixed record of coseismic subsidence and uplift that we document illustrates the variability of down-dip and lateral slip distribution at the overlap of the 2010 and 1960 ruptures, showing that ruptures have repeatedly propagated into, but not through the Arauco Peninsula and suggesting the area has persisted as a long-term impediment to slip through at least seven of the last megathrust earthquakes (∼600 years).

  15. Stratigraphic and compositional complexities of the late Quaternary Lethe tephra in South-central Alaska

    Science.gov (United States)

    Riehle, J.R.; Ager, T.A.; Reger, R.D.; Pinney, D.S.; Kaufman, D.S.

    2008-01-01

    Recently discovered Lethe tephra has been proposed as a latest Pleistocene marker bed in Bristol Bay lowland NE to the Cook Inlet region, Alaska, on the basis of correlations involving a single "Lethe average" glass composition. Type deposits in the Valley of Ten Thousand Smokes, however, are chemically heterogeneous-individual lapilli as well as aggregate ash deposits have glass compositions that range from the average mode to much higher SiO2 and K2O. Moreover, a lake-sediment core from the Cook Inlet region contains one ash deposit similar to "Lethe average" and other, closely underlying deposits that resemble a mixture of the average mode and high-Si high-K mode of proximal deposits. Synthesis of previously published radiocarbon ages indicates a major eruption mainly of "Lethe average" mode about 13,000 14C yr BP. As many as six deposits in the Cook Inlet region-five chiefly "Lethe average" mode-range from about 13,000 to 15-16,000 14C yr BP, and an early Holocene deposit in the Bristol Bay lowland extends the minimum age range of Lethe tephra throughout this region to 8000 14C yr BP. Because of the appearance of "Lethe average" composition in multiple deposits spanning thousands of years, we urge caution when using a Lethe-like composition as a basis for inferring a latest Pleistocene age of a tephra deposit in south-central Alaska. Linear variation plots suggest that magma mixing caused the Lethe heterogeneity; multiple magmas were involved as well in other large pyroclastic eruptions such as Katmai (Alaska) and Rotorua (New Zealand). Lethe is an example of a heterogeneous tephra that may be better compared with other tephras by use of plots of individual analytical points rather than by calculating similarity coefficients based on edited data. ?? 2006 Elsevier Ltd and INQUA.

  16. Climate-Induced Change in South Central Siberia: Predictions Versus Current Observations

    Science.gov (United States)

    Soja, A. J.; Tchebakova, N. M.; Parfenova, E. I.; Shishikin, A.; Kanzai, V.; Westberg, D. J.; Sukhinin, A. I.; Ivanova, G. A.; Stackhouse, P. W.

    2007-12-01

    Atmosphere Ocean General Circulations Models (AOGCM) are in agreement that Siberia is expected to experience warming in excess of 40% above global mean temperature increases by 2100. Moreover, it is predicted temperature increases will be evident in both the summer and winter. In association with changes in climate, the extent of the fire season, the amount of area burned and fire severity are predicted to increase. Fire regime increases are predicted to be the catalyst for ecosystem change, which will force ecosystems to move more rapidly towards equilibrium with the climate. Bioclimatic model results predict expansive changes in ecosystems, from a landscape dominated by taiga to a landscape dominated by steppe and forest-steppe. The focus of this investigation is on south, central Siberia in the Sayan Mountains and the Tyvan Republic, where one would expect to find the initial signs of climate change. The Sayan mountain range offers relatively abrupt change in ecosystems that are often defined by altitude, temperature and precipitation. Tyva is located at a vulnerable southern border, south of the Sayan, and contains 9 Biospheric Reserves, each representing distinct ecosystems. Additionally, Tyva is the home of several relic Pinus sylvestris forests. In these regions, January temperature increases have exceeded those predicted by the Hadley Centre scenario for 2090, and July temperatures are well below predictions. Predicted increases in rainfall are not apparent, and generally, precipitation change has been negative. The growing season length has already increased by about 6 to 12 days. Consequently, several of the relic pine forests have burned (some repeatedly), and natural regeneration is not visible at several sites, even one that had been re-planted on several occasions. In the last decades, these regions have experienced changes in climate and, potentially, initial signs of ecosystem change. In this report, we present a concentrated view of one region that

  17. Viability criteria for steelhead of the south-central and southern California coast

    Science.gov (United States)

    Boughton, David A.; Adams, Peter B.; Anderson, Eric; Fusaro, Craig; Keller, Edward A.; Kelley, Elsie; Lentsch, Leo; Nielsen, Jennifer L.; Perry, Katie; Regan, Helen; Smith, Jerry; Swift, Camm C.; Thompson, Lisa; Watson, Fred

    2007-01-01

    Recovery planning for threatened and endangered steelhead requires measurable, objective criteria for determining an acceptably low risk of extinction. Here we propose viability criteria for two levels of biological organization: individual populations, and groups of populations within the SouthCentral/Southern California Coast Steelhead Recovery Planning Domain. For populations, we adapt criteria commonly used by the IUCN (The World Conservation Union) for identifying at-risk species. For groups of populations we implement a diversity-based “representation and redundancy rule,” in which diversity includes both life-history diversity and biogeographic groupings of populations. The resulting criteria have the potential for straightforward assessment of the risks posed by evolutionary, demographic, environmental, and catastrophic factors; and are designed to use data that are readily collected. However, our prescriptive approach led to one criterion whose threshold could not yet be specified due to inadequate data, and others in which the simplicity of the criteria may render them inefficient for populations with stable run sizes or stable life-history polymorphisms. Both of these problems could likely be solved by directed programs of research and monitoring aimed at developing more efficient (but equally risk-averse) “performance-based criteria.” Of particular utility would be data on the natural fluctuations of populations, research into the stabilizing influence of life-history polymorphisms, and research on the implications of drought, wildfires, and fluvial sediment regimes. Research on estuarine habitat could also yield useful information on the generality and reliability of its role as nursery habitat. Currently, risk assessment at the population level is not possible due to data deficiency, highlighting the need to implement a comprehensive effort to monitor run sizes, anadromous fractions, spawner densities and perhaps marine survival. Assessment at

  18. Comparative Study Of Focal Mechanisms In South Central Chile Before And After The 2010 Maule Earthquake

    Science.gov (United States)

    Agurto, H.; Rietbrock, A.; Ryder, I. M.; Haberland, C. A.

    2011-12-01

    On 27 February 2010, a Mw=8.8 earthquake occurred off the coast of south central Chile rupturing nearly 500 km of the subduction zone plate interface. The earthquake also generated a tsunami and caused more than 500 fatalities. The largest earthquakes recorded have taken place along subduction margins (e.g. Chile 1960, 2010, Andaman-Sumatra 2004, Japan 2011) and understanding their rupture mechanisms and deformation regimes is therefore of vital importance. From November 2004 to October 2005, the TIPTEQ project ("From The Incoming Plate to megaThrust EarthQuake"; Rietbrock et al., 2007; Haberland et al., 2009) maintained a network of 120 seismic stations inland and 10 stations at sea between 37 and 39° lat. S., continuously-recording and monitoring the seismicity occurring in the area before the 2010 Maule earthquake. By using first motion polarities and moment tensor inversion we have computed and analyzed focal mechanisms for a subset of data from these records. We found thrust faulting along the subduction interface down to a depth of ~30 km, followed by a gap in the seismicity and then deeper earthquakes showing diverse faulting mechanisms more sparsely distributed within the subducting plate. We also see strike-slip crustal faulting occurring down to ~12 km depth within the area of the Lanalhue fault. The most striking observation is the presence of deep (40 km) normal faulting seismicity in the fore-arc, close to the trench. We have now started to analyze the International Maule Aftershocks Dataset (IMAD) of the 2010 earthquake in the southern rupture region. Again we observe thrust faulting in the subduction interface and a seismic gap between an upper and lower zone of seismicity along the interface. By comparison of the pre- and post-earthquake datasets we are investigating whether the Maule earthquake caused any changes in the style of deformation in this part of Chile. References Haberland, C., A. Rietbrock, D. Lange, K. Bataille, and T. Dahm (2009

  19. Environmental Factors Affecting the Whale Shark Aggregation site in the South Central Red Sea

    KAUST Repository

    Hozumi, Aya

    2015-12-01

    Motivation behind the spring whale shark (Rhincodon typus) aggregation in Al-Lith, on the Saudi Arabian coast of the South Central Red Sea, is uncertain. A plausible hypothesis is that whale sharks gather to feed on high prey density, leading to questions about the cause of the prey density. A bottom-up process fueled by nutrient input or accumulation from physical advection could create a peak in prey biomass. Wastewater discharged from an aquaculture facility could affect productivity or provide a chemosensory cue for whale sharks. Yet, basic physico-biological oceanography of this region is unresolved. Monthly profiles, long-term moorings, and spatial surveys were used to describe the temporal variability of potential prey biomass and water masses in this region for the first time. Plankton abundance of individuals larger than ~0.7 cm did not peak during whale shark season. Rather, a decrease coinciding the trailing end of whale shark detections was observed. Sites 180 m apart had differences in acoustic backscatter, suggesting small-scale biomass patchiness, supporting the small-scale variability in whale shark habitat selectivity. Red Sea Deep Water, a nutrient-rich water mass formed in the northern Red Sea, appeared in July at the same time the Tokar wind jet from the Sudanese mountain gap is the highest. Gulf of Aden Water, a nutrient-rich water mass from the Indian Ocean, arrived as episodes from May to September, contrary to previous expectations that the water arrives continuously. It is unlikely that these natural nutrient sources are directly responsible for the high prey density attracting the whale sharks. The aquaculture plume, observed at the aggregation site, had a distinct seasonality from the ambient waters. The plume’s highest salinity (>48) approached the extreme limits of coral tolerances. Nutrient concentrations (nitrate, nitrite, phosphate, silica), suspended particulate matter, phytoplankton biomass, bacteria and cyanobacteria cell counts

  20. Diverging Histories of the Liberty Creek and Iceberg Lake Blueschist Bodies, south central Alaska

    Science.gov (United States)

    Day, E. M.; Pavlis, T. L.; Amato, J. M.

    2011-12-01

    New studies of the Liberty Creek and Iceberg Lake blueschist bodies of south central Alaska indicate that despite structural similarities, these blueschist bodies are derived from a different protolith and were metamorphosed to blueschist facies at distinctly different times. Both blueschists are located just south of the Border Ranges Fault (BRF) within outcrop belts of the McHugh Complex, a low-grade mélange assemblage that is now known from detrital zircon studies to consist of two distinct assemblages: a Jurassic to Earliest Cretaceous assemblage and a Late Cretaceous assemblage. The BRF is a megathrust system that represents the Late Triassic-Early Jurassic initiation of southern Alaskan subduction. Large scale (1:24,000) mapping revealed similar fabric overprint histories, epitomized by a previously undescribed youngest vertical N-S trending crenulation cleavage in both blueschist bodies which implies a structural correlation despite their separation of ~100 kilometers along strike. Despite structural similarities detrital zircon studies show that the Liberty Creek and Iceberg Lake blueschists do not have a similar maximum age of deposition. Thirteen samples from the Iceberg Lake blueschist were processed, none of which produced detrital zircons. Samples from the McHugh Complex greenschists that surround the Iceberg Lake blueschist produced numerous zircons indicating a Late Jurassic (~160 Ma) maximum age of deposition. Three out of sixteen samples from the Liberty creek blueschist produced detrital zircons indicating maximum depositional ages ranging from Late Jurassic (~160.1 Ma, n=64 grains; ~152.25 Ma, n=68 grains) to Early Cretaceous (~137.1 Ma, n=95 grains). The Late Jurassic dates are consistent with maximum depositional ages determined by Amato and Pavlis (2010) for McHugh Complex rocks along Turnagain Arm near Anchorage, AK. Sisson and Onstott (1986) reported a metamorphic cooling age of 185 Ma for the Iceberg Lake blueschist, thus, although no

  1. Recharge of an Unconfined Pumice Aquifer: Winter Rainfall Versus Snow Pack, South-central Oregon

    Science.gov (United States)

    Cummings, M. L.; Weatherford, J. M.; Eibert, D.

    2015-12-01

    Walker Rim study area, an uplifted fault block east of the Cascade Range, south-central Oregon, exceeds 1580 m elevation and includes Round Meadow-Sellers Marsh closed basin, and headwaters of Upper Klamath Basin, Deschutes Basin, and Christmas Lake Valley in the Great Basin. The water-bearing unit is 2.8 to 3.0 m thick Plinian pumice fall from the Holocene eruption of Mount Mazama, Cascade Range. The perched pumice aquifer is underlain by low permeability regolith and bedrock. Disruption of the internal continuity of the Plinian pumice fall by fluvial and lacustrine processes resulted in hydrogeologic environments that include fens, wet meadows, and areas of shallow water table. Slopes are low and surface and groundwater pathways follow patterns inherited from the pre-eruption landscape. Discharge for streams and springs and depth to water table measured in open-ended piezometers slotted in the pumice aquifer have been measured between March and October, WY 2011 through WY2015. Yearly occupation on same date has been conducted for middle April, June 1st, and end of October. WY2011 and WY2012 received more precipitation than the 30 year average while WY2014 was the third driest year in 30 years of record. WY2014 and WY2015 provide an interesting contrast. Drought conditions dominated WY2014 while WY2015 was distinct in that the normal cold-season snow pack was replaced by rainfall. Cumulative precipitation exceeded the 30-year average between October and March. The pumice aquifer of wet meadows and areas of shallow water table experienced little recharge in WY2015. Persistence of widespread diffuse discharge from fens declined by middle summer as potentiometric surfaces lowered into confining peat layers or in some settings into the pumice aquifer. Recharge of the perched pumice aquifer in rain-dominated WY2015 was similar to or less than in the snow-dominated drought of WY2014. Rain falling on frozen ground drove runoff rather than aquifer recharge.

  2. From The Mountain To The Sea: Exchange Between The South-Central Highlands And The South Coast During The Early Horizon Period

    OpenAIRE

    Young, Michele

    2017-01-01

    This article reviews the evidence of the exchange of obsidian and cinnabar, highly coveted resources that traveled in prehistoric Peru from the south-central highlands to the Paracas culture area. The evidence for exchange of these materials is compared with evidence of cultural exchange between the coast and the south-central highlands, focusing on ceramic materials uncovered from excavations at the archaeological site Atalla, located in the region of Huancavelica, Peru. The article argues t...

  3. U.S. Department of the Interior South Central Climate Science Center strategic science plan, 2013--18

    Science.gov (United States)

    Winton, Kim T.; Dalton, Melinda S.; Shipp, Allison A.

    2013-01-01

    The Department of the Interior (DOI) recognizes and embraces the unprecedented challenges of maintaining our Nation’s rich natural and cultural resources in the 21st century. The magnitude of these challenges demands that the conservation community work together to develop integrated adaptation and mitigation strategies that collectively address the impacts of climate change and other landscape-scale stressors. On September 14, 2009, DOI Secretary Ken Salazar signed Secretarial Order 3289 (amended February 22, 2010) entitled, “Addressing the Impacts of Climate Change on America’s Water, Land, and Other Natural and Cultural Resources.” The Order establishes the foundation for two partner-based conservation science entities to address these unprecedented challenges: Climate Science Centers (CSCs and Landscape Conservation Cooperatives (LCCs). CSCs and LCCs are the Department-wide approach for applying scientific tools to increase understanding of climate change and to coordinate an effective response to its impacts on tribes and the land, water, ocean, fish and wildlife, and cultural-heritage resources that DOI manages. Eight CSCs have been established and are managed through the U.S. Geological Survey (USGS) National Climate Change and Wildlife Science Center (NCCWSC); each CSC works in close collaboration with their neighboring CSCs, as well as those across the Nation, to ensure the best and most efficient science is produced. The South Central CSC was established in 2012 through a cooperative agreement with the University of Oklahoma, Texas Tech University, Louisiana State University, the Chickasaw Nation, the Choctaw Nation of Oklahoma, Oklahoma State University, and NOAA’s Geophysical Fluid Dynamics Lab; hereafter termed the ”Consortium” of the South Central CSC. The Consortium has a broad expertise in the physical, biological, natural, and social sciences to address impacts of climate change on land, water, fish and wildlife, ocean, coastal, and

  4. The Eocene Big Timber stock, south-central Montana: Development of extensive compositional variation in an arc-related intrusion by side-wall crystallization and cumulate glomerocryst remixing

    Science.gov (United States)

    du Bray, E.A.; Harlan, S.S.

    1996-01-01

    The Eocene Big Timber stock in the Crazy Mountains of south-central Montana is an elliptical, 8 by 13 km, compositionally and texturally diverse composite intrusion with a well-developed radial dike swarm. A sharp intrusive contact separates its two phases: the core of the intrusion is fine-grained quartz monzodiorite, and the volumetrically dominant remainder is composed of medium-grained diorite and gabbro. Differentiation-related major oxide variation within the stock is extensive and spatially nonsystematic. However, abundances of most trace elements were not strongly influenced by differentiation; late zircon and apatite fractionation caused moderate heavy and slight light rare earth element abundance depletions, respectively. Mineral compositions and assemblages indicate crystallization between ???950 and 700??C at a pressure of ???0.8 kbar (3 km). Mixing models indicate that fractionation of varying amounts of plagioclase, orthopyroxene, clinopyroxene, magnesio-hastingsite, hornblende, biotite, titanite, apatite, and magnetite (the stock's principal constituents, with quartz and potassium feldspar) and remixing of these minerals and residual liquids controlled compositional evolution in the reservoir. Crystals apparently nucleated at the reservoir wall while residual silicate liquid was displaced inward and remixed. Some crystals were plucked from the solidification front, as indicated by glomerocrysts present throughout the stock, and also remixed with residual liquid. Solidification of the reservoir represented by the stock involved heat loss to enclosing wall rock, side-wall crystallization, and subsequent, variably effective, crystal-liquid remixing. This process is an important variant of conventionally invoked models pertaining to solidification of intrusions and explains extensive, relatively nonsystematic compositional variation. The genesis of compositional evolution in other intrusions characterized by extensive, spatially nonsystematic variation

  5. Limnology of Big Lake, south-central Alaska, 1983-84

    Science.gov (United States)

    Woods, Paul F.

    1992-01-01

    The limnological characteristics and trophic state of Big Lake in south-central Alaska were determined from the results of an intensive study during 1983-84. The study was begun in response to concern over the potential for eutrophication of Big Lake, which has experienced substantial residential development and recreational use because of its proximity to Anchorage. The east and west basins of the 1,213 square-hectometer lake were each visited 36 times during the 2-year study to obtain a wide variety of physical, chemical, and biological data. During 1984, an estimate was made of the lake's annual primary production. Big Lake was classified as oligotrophic on the basis of its annual mean values for total phosphorus (9.5 micrograms per liter), total nitrogen (209 micrograms per liter), chlorophyll-a (2.5 micrograms per liter), secchi-disc transparency (6.3 meters), and its mean daily integral primary production of 81.1 milligrams of carbon fixed per square meter. The lake was, however, uncharacteristic of oligotrophic lakes in that a severe dissolved-oxygen deficit developed within the hypolimnion during summer stratification and under winter ice cover. The summer dissolved-oxygen deficit resulted from the combination of strong and persistent thermal stratification, which developed within 1 week of the melting of the lake's ice cover in May, and the failure of the spring circulation to fully reaerate the hypolimnion. The autumn circulation did reaerate the entire water column, but the ensuing 6 months of ice and snow cover prevented atmospheric reaeration of the water column and led to development of the winter dissolved-oxygen deficit. The anoxic conditions that eventually developed near the lake bottom allowed the release of nutrients from the bottom sediments and facilitated ammonification reactions. These processes yielded hypolimnetic concentrations of nitrogen and phosphorus compounds, which were much larger than the oligotrophic concentrations measured

  6. Relationship between Clinical Presentation and Visual Outcome in Postoperative and Posttraumatic Endophthalmitis in South Central India

    Directory of Open Access Journals (Sweden)

    Das Taraprasad

    2005-03-01

    Full Text Available PURPOSE: To determine risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis in a large referral center in south central India. METHODS: In this prospective observational series the authors examined 388 patients of postoperative (n= 206 and posttraumatic (n= 182 endophthalmitis at the L V Prasad Eye Institute in Hyderabad, India between 1991 and 1997.The analysis was confined to 236 patients-128 (62.1% postoperative and 108 (59.3% posttraumatic patients who were followed for a minimum period of 3 months. A detailed protocol was followed. Chi-square and logistic regression analysis were used to determine risk factors for visual outcome worse than 6/18 and worse than 6/120. RESULTS: Postoperative endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120 included intracapsular cataract surgery, poor presenting visual acuity, presence of vitreous cells, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In the multivariate analysis, visual acuity of < light perception (LP at presentation was associated with a 3-month postoperative visual acuity of < 6/18, with an odds ratio of 5.85 [ 1.25 - 27.42, 95% CI], and vitreous membranes seen on ultrasonography was associated with a final visual acuity of < 6/120, with an odds ratio of 2.47 [1.05 - 5.83, 95% CI]. Posttraumatic endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120 included a retained intraocular foreign body (IOFB, trauma by needle (hypodermic or sewing, poor presenting visual acuity, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In multivariate analysis, IOFB was associated with a 3-month follow-up visual acuity of < 6

  7. Late Pleistocene to Holocene tephrostratigraphy of the Lonquimay Volcano, South Central Chile

    Science.gov (United States)

    Gilbert, D.; Freundt, A.; Kutterolf, S.; Burkert, C.

    2010-12-01

    The Lonquimay Volcanic Complex (LVC) in South Central Chile (38.38°S, 71.58°W) is part of the Southern Volcanic Zone of the Andes, which formed in response to the subduction of the Nazca Plate beneath the South American Plate. During the course of its magmatic evolution, the LVC produced explosive eruptions documented in the succession of widespread tephra deposits, as well as large lava flows that originated from the main edifice and several adjacent minor eruptive centers. The last eruptive phase in Lonquimays volcanic evolution occurred from 1988-1990. It led to the formation of the Navidad cinder cone with its associated 10.2 km long lava flow, and a widely distributed tephra blanket of andesitic composition (Moreno and Gardeweg, 1989). During recent field work we reinvestigated and complemented the LVC tephrostratigraphy as originally established by Polanco (1998)by detailed logging of 22 outcrops and collecting 126 stratigraphically controlled samples that were analyzed for their matrix glass, mineral and bulk rock compositions. This data set allows us to verify and extend the field-based correlations, and to establish a tephrostratigraphy for the LVC that comprises 15 stratigraphic units (LQA-LQO) and provides a framework for ongoing investigations of the petrogenetic evolution of the LVC. The stratigraphic record identifies at least 13 explosive eruptions of VEI > 3 that occurred since the last glaciation period (17150 a BP, McCulloch et al. 2000). Magmatic compositions of the tephra deposits range from basaltic scoriae (51wt% SiO2) to evolved dacitic pumice lapilli layers (67wt% SiO2), and thus have a wider compositional range than the chemically distinct andesitic lavas (57-63wt%) of the LVC. The vertical succession of tephra compositions reflects four periods of progressive magmatic differentiation, each successively tapped by several eruptions. The maximum degree of fractionation reached during these periods increases to younger ages. The

  8. Stream seepage and groundwater levels, Wood River Valley, south-central Idaho, 2012-13

    Science.gov (United States)

    Bartolino, James R.

    2014-01-01

    Stream discharge and water levels in wells were measured at multiple sites in the Wood River Valley, south-central Idaho, in August 2012, October 2012, and March 2013, as a component of data collection for a groundwater-flow model of the Wood River Valley aquifer system. This model is a cooperative and collaborative effort between the U.S. Geological Survey and the Idaho Department of Water Resources. Stream-discharge measurements for determination of seepage were made during several days on three occasions: August 27–28, 2012, October 22–24, 2012, and March 27–28, 2013. Discharge measurements were made at 49 sites in August and October, and 51 sites in March, on the Big Wood River, Silver Creek, their tributaries, and nearby canals. The Big Wood River generally gains flow between the Big Wood River near Ketchum streamgage (13135500) and the Big Wood River at Hailey streamgage (13139510), and loses flow between the Hailey streamgage and the Big Wood River at Stanton Crossing near Bellevue streamgage (13140800). Shorter reaches within these segments may differ in the direction or magnitude of seepage or may be indeterminate because of measurement uncertainty. Additional reaches were measured on Silver Creek, the North Fork Big Wood River, Warm Springs Creek, Trail Creek, and the East Fork Big Wood River. Discharge measurements also were made on the Hiawatha, Cove, District 45, Glendale, and Bypass Canals, and smaller tributaries to the Big Wood River and Silver Creek. Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-surface altitude of the confined aquifer have similar topology to those on maps of October 2006 conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer rose by

  9. Redistribution of cesium-137 in southeastern watersheds

    International Nuclear Information System (INIS)

    McHenry, J.R.; Ritchie, J.C.

    1975-01-01

    Sediment samples from 14 southeastern agricultural reservoirs and surface samples from representative soils from the contributing water shed areas were analyzed for 137 Cs. The concentrations of 137 Cs measured reflect the nature of the watershed, its cover, its use, and man's activities. Since the redistribution of 137 Cs was assumed to result from soil erosion, recent erosion rates can be calculated from the measured 137 Cs accumulations in sediments and from the decreases in the 137 Cs calculated to have been deposited on upland soils. Measured concentrations of 137 Cs ranged from 14 to 158 nCi/m 2 in surface soils. As much as 525 nCi/m 2 of 137 Cs was measured in the deposited sediment profile. Watershed budgets for 137 Cs were calculated for three representative watersheds using available sediment survey information and the measured 137 Cs concentrations

  10. Climate, wildfire, and erosion ensemble foretells more sediment in western USA watersheds

    Science.gov (United States)

    Sankey, Joel B.; Kreitler, Jason; Hawbaker, Todd J.; McVay, Jason L.; Miller, Mary Ellen; Mueller, Erich R.; Vaillant, Nicole M.; Lowe, Scott E.; Sankey, Temuulen T.

    2017-09-01

    The area burned annually by wildfires is expected to increase worldwide due to climate change. Burned areas increase soil erosion rates within watersheds, which can increase sedimentation in downstream rivers and reservoirs. However, which watersheds will be impacted by future wildfires is largely unknown. Using an ensemble of climate, fire, and erosion models, we show that postfire sedimentation is projected to increase for nearly nine tenths of watersheds by >10% and for more than one third of watersheds by >100% by the 2041 to 2050 decade in the western USA. The projected increases are statistically significant for more than eight tenths of the watersheds. In the western USA, many human communities rely on water from rivers and reservoirs that originates in watersheds where sedimentation is projected to increase. Increased sedimentation could negatively impact water supply and quality for some communities, in addition to affecting stream channel stability and aquatic ecosystems.

  11. An index of reservoir habitat impairment

    Science.gov (United States)

    Miranda, L.E.; Hunt, K.M.

    2011-01-01

    Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

  12. Water resources review: Wheeler Reservoir, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Wallus, R.; Cox, J.P.

    1990-09-01

    Protection and enhancement of water quality is essential for attaining the full complement of beneficial uses of TVA reservoirs. The responsibility for improving and protecting TVA reservoir water quality is shared by various federal, state, and local agencies, as well as the thousands of corporations and property owners whose individual decisions affect water quality. TVA's role in this shared responsibility includes collecting and evaluating water resources data, disseminating water resources information, and acting as a catalyst to bring together agencies and individuals that have a responsibility or vested interest in correcting problems that have been identified. This report is one in a series of status reports that will be prepared for each of TVA's reservoirs. The purpose of this status report is to provide an up-to-date overview of the characteristics and conditions of Wheeler Reservoir, including: reservoir purposes and operation; physical characteristics of the reservoir and the watershed; water quality conditions: aquatic biological conditions: designated, actual, and potential uses of the reservoir and impairments of those uses; ongoing or planned reservoir management activities. Information and data presented here are form the most recent reports, publications, and original data available. 21 refs., 8 figs., 29 tabs.

  13. SWAT-based streamflow and embayment modeling of Karst-affected Chapel branch watershed, South Carolina

    Science.gov (United States)

    Devendra Amatya; M. Jha; A.E. Edwards; T.M. Williams; D.R. Hitchcock

    2011-01-01

    SWAT is a GIS-based basin-scale model widely used for the characterization of hydrology and water quality of large, complex watersheds; however, SWAT has not been fully tested in watersheds with karst geomorphology and downstream reservoir-like embayment. In this study, SWAT was applied to test its ability to predict monthly streamflow dynamics for a 1,555 ha karst...

  14. Tree-ring chronologies and stable carbon isotopic composition reveal impacts of hydro-climate change on bottomland hardwood forests of South-Central Texas

    Science.gov (United States)

    Deshpande, A. G.; Lafon, C. W.; Hyodo, A.; Boutton, T. W.; Moore, G. W.

    2017-12-01

    Over the last three decades, South-Central Texas has experienced an increase in frequency and intensity of hydro-climatic anomalies such as extreme droughts and floods. These extreme events can have negative impacts on forest health and can strongly alter a wide range of ecosystem processes. Tree increment growth in bottomland hardwood forests is influenced by droughts and floods, which affects the carbon isotope values (δ13C) in tree-ring cellulose. This study aims to assess the impacts of hydro-climate change on the growth and physiological response of bottomland hardwood forests by investigating variations in radial growth and tree-ring carbon isotopic composition. Annual ring-width chronologies for 41 years (1975-2016) were developed from 24 water oak (Quercus nigra) trees at 4 sites along a 25 km transect located in the San Bernard River watershed. The δ13C values in cellulose were measured from 4-year ring composites including years with anomalously high and low precipitation. Dendroclimatology analysis involved correlating ring-width index with precipitation records and Palmer Drought Sensitivity Index (PDSI). Radial growth was more closely associated with spring-summer (Feb-Aug) precipitation (R2 = 0.42, pstress, as indicated by narrower growth rings and increased cellulose δ13C. However, the inter-site variation in δ13C indicated large hydro-climatic variation between sites (2.79-4.24‰ for wet years and 0.53-1.50‰ for drought years). δ13C values showed an increase of 0.78‰ and 2.40‰ from the wettest (1991-1994) to the driest period (2008-2011) at two of our sites, possibly due to drought-induced moisture-deficit-stress. However, at the other two sites, the δ13C values of tree rings from the same periods decreased by 0.65‰ and 1.19‰, possibly emanating from flooding-induced stress caused by waterlogging. This study provides insights on how hydro-climatic variations affect riparian forest health in the region and acts as a baseline for

  15. Ecosystem Modeling in the South Central US: A Synthesis of Current Models toward the Development of Coupled Models

    Science.gov (United States)

    Kc, M.

    2015-12-01

    Ecosystem services and products are the foundation of sustainability for regional and global economy since we are directly or indirectly dependent on the ecosystem services like food, livestock, water, air, wildlife etc. It has been increasingly recognized that for sustainability concerns, the conservation problems need to be addressed in the context of entire ecosystems. This approach known as the ecosystem approach is fundamental to managing earth's finite resources since it addresses the interactions that link biotic systems, of which human, flora and fauna are integral parts, with the physical systems on which they depend. This approach is even more vital in the 21st century with formidable increasing human population and rapid changes in global environment. This study is being conducted to find the state of the science of ecosystem models in the South-Central region of US. The propose of the project is to conduct a systematic review and synthesize relevant information on the current state of the science of ecosystem modeling in the South-Central region of US toward coupling these models with climate, agronomic, hydrologic, economic or management models to better represent ecosystem dynamics as affected by climate change and human activities; and hence gain more reliable predictions of future ecosystem functions and service in the region. Better understandings of such processes will increase our ability to predict the ecosystem responses and feedbacks to environmental and human induced change in the region so that decision makers can make an informed management decisions of the ecosystem.

  16. Life History of Emerita analoga(Stimpson) (Anomura, Hippidae) in a Sandy Beach of South Central Chile

    Science.gov (United States)

    Contreras, H.; Defeo, O.; Jaramillo, E.

    1999-01-01

    Emerita analoga(Crustacea, Anomura, Hippidae) is a characteristic species of the swash zone of temperate sandy beaches of the Eastern Pacific. To analyse the reproductive biology and population dynamics of a population located in south central Chile, monthly samples were collected from an exposed sandy beach (Mehuín, c. 39°S). Samples were taken from June 1989 through May 1991, and between June 1992 and May 1993, from the uppermost beach levels and the lowest level of the swash zone. The highest abundances of E. analogaoccurred during the late spring-early summer. The highest mean fecundity values occurred in winter and summer, and the lowest during spring. The size at which females reach sexual maturity was found to be 16-17 mm (about 12 months after recruitment). Two recruitment peaks were found: one during early autumn, and the other during spring. Growth analyses showed that growth rates of females were higher than those of males for the three annual periods analysed. It is concluded that differences in size at sexual maturity and in growth rates can explain sexual dimorphism in adult E. analogain south central Chile.

  17. Animals′ Role in Proper Behaviour: Cheŵa Women′s Instructions in South-Central Africa

    Directory of Open Access Journals (Sweden)

    Leslie F Zubieta

    2016-01-01

    Full Text Available The most common role of animals in the Cheŵa culture of south-central Africa is twofold: they are regarded as an important source of food, and they also provide raw materials for the creation of traditional medicines. Animals, however, also have a nuanced symbolic role that impacts the way people behave with each other by embodying cultural protocols of proper — and not so proper — behaviour. They appear repeatedly in storytelling and proverbs to reference qualities that people need to avoid or pursue and learn from the moral of the story in which animals interplay with each other, just as humans do. For example, someone who wants to prevent the consequences of greed is often advised to heed hyena stories and proverbs. My contribution elaborates on Brian Morris's instrumental work in south-central Africa, which has permitted us to elucidate the symbolism of certain animals and the perception of landscape for Indigenous populations in this region. I discuss some of the ways in which animals have been employed to teach and learn proper behaviour in a particular sacred ceremony of the Cheŵa people which takes place in celebration of womanhood: Chinamwali.

  18. Environmental flows in the context of small reservoirs in Ghana

    Science.gov (United States)

    Gao, Y.; Kirshen, P.; Vogel, R.; Walker, P.

    2009-04-01

    Modification of rivers by dams reduces the magnitude and frequency of floods, and impacts the entire flow regime. In many cases, these modifications have adversely affected the ecological and hydrological integrity of the watershed as well as impacting food security and livelihood choices of the local community. There is now an increasing consensus that modification to river flows needs to be balanced with maintenance of essential water-dependent ecological services. Many small multi-purpose reservoirs have been built in West Africa, where rainfall is highly variable, and droughts and flash floods are frequent. These small reservoirs are an important source of water for domestic use, livestock watering, small-scale irrigation and other beneficial uses in rural communities. The small reservoirs are hydrologically linked by their associated stream network. The reservoirs alter the hydrology of the streams and the groundwater resources within the region. When an individual reservoir is considered, alteration to the entire watershed is usually not significant. However, when considered as a system, together the small reservoirs store a significant quantity of water and influence downstream flows. The small reservoirs have rarely been considered as a system, thus little consideration has been given to their collective impact on the natural environment and livelihoods of the local population in the long term. Furthermore, the impact is difficult to quantify given the diffuse nature of the small reservoirs. Therefore, a comprehensive environmental flow assessment is needed to investigate the effect of the small reservoirs as a system on the watershed, and appropriate water policy should be formulated to implement the finding from the assessment. Our project is specifically aimed at addressing this topic. We will present a case study conducted in the Upper East Region of Ghana and will discuss the findings on the hydrological, ecological and socio-economic implications of

  19. Watershed Management Partnership Agreement

    Science.gov (United States)

    On November 19, 2004, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers signed the Watershed Management Partnership Agreement to promote watershed health, economic sustainability and community vitality through effective manageme

  20. Managing Watersheds with WMOST

    Science.gov (United States)

    The Watershed Management Optimization Support Tool (WMOST) allows water-resource managers and planners to screen a wide range of practices for cost-effectiveness in achieving watershed or water utilities management goals.

  1. Adopt Your Watershed

    Data.gov (United States)

    U.S. Environmental Protection Agency — Adopt Your Watershed is a Website that encourages stewardship of the nation's water resources and serves as a national inventory of local watershed groups and...

  2. Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

    Science.gov (United States)

    Bartolino, James R.; Adkins, Candice B.

    2012-01-01

    metamorphosed to some degree, thus rock types and their relationships vary over distance. Quaternary-age sediment and basalt compose the primary source of groundwater in the Wood River Valley aquifer system. These Quaternary deposits can be divided into three units: a coarse-grained sand and gravel unit, a fine-grained silt and clay unit, and a single basalt unit. The fine- and coarse-grained units were primarily deposited as alluvium derived from glaciation in the surrounding mountains and upper reaches of tributary canyons. The basalt unit is found in the southeastern Bellevue fan area and is composed of two flows of different ages. Most of the groundwater produced from the Wood River Valley aquifer system is from the coarse-grained deposits. The altitude of the pre-Quaternary bedrock surface in the Wood River Valley was compiled from about 1,000 well-driller reports for boreholes drilled to bedrock and about 70 Horizontal-to-Vertical Spectral Ratio (HVSR) ambient-noise measurements. The bedrock surface generally mimics the land surface by decreasing down tributary canyons and the main valley from north to south; it ranges from more than 6,700 feet in Baker Creek to less than 4,600 feet in the central Bellevue fan. Most of the south-central portion of the Bellevue fan is underlain by an apparent topographically closed area on the bedrock surface that appears to drain to the southwest towards Stanton Crossing. Quaternary sediment thickness ranges from less than a foot on main and tributary valley margins to about 350 feet in the central Bellevue fan. Hydraulic conductivity for 81 wells in the study area was estimated from well-performance tests reported on well-driller reports. Estimated hydraulic conductivity for 79 wells completed in alluvium ranges from 1,900 feet per day (ft/d) along Warm Springs Creek to less than 1 ft/d in upper Croy Canyon. A well completed in bedrock had an estimated hydraulic conductivity value of 10 ft/d, one well completed in basalt had a value of

  3. Geology of the State of Morelos and contiguous areas in south-central Mexico

    Science.gov (United States)

    Fries, Carl F.

    1959-01-01

    The area described lies in south-central Mexico and embraces all but the southeastern corner and easternmost border of the State of Moreles, the second smallest State in the Mexican Republic. It includes small contiguous parts of the State of Mexico, in the northeastern corner, and of the State of Guerrero in the southwestern corner. Limiting geographic coordinates are 98 45 to 99 39 west longitude and 18 18 to 19 08 north latitude, the northern boundary being only 35 km south of Mexico City, capital of the Republic. The geological map does not cover the entire rectangle outlined, but is irregular in form and measures roughly 4150 sq. km, three-quarters of it representing two0thirds of the State of Moreles and the rest lying outside the State. The region ranges in altitude from 730 m above sea level at Iguala near the south edge of the map, to a general level of about 3000 m at the north edge, although individual peaks rise to 3900 m and Popocatepetl Volcano, a few kilometers east of the northeastern border of the map, rises to 5452 m above sea level. Annual rainfall ranges from a minimum of about 640 mm in the low country, to 1200 mm and more at altitudes above 2000 m. Most of it falls in summer between June and September. Winter frosts are rare below 1800 m. The climate is of savanna to steppe type; soils are thin and may be classified as belonging to the tachernoses group, with strong development of calcareous evaporates (caliche) at altitudes below 1800 m. The northern border of the area forms the southern half of the late Pliocene to Recent Neo-volcanic Belt of basic volcanism that crosses Mexico in the direction N. 80 W., and thus has constructional topography. The rest of the area belongs to the Balsas Basin physiographic province, which is characterized by maturely dissected terrain tributary to the large Balsas River. All but the southwestern corner of the area drains southward via the Amacuzac River into the Mexcala-Balsas River, and thence westward into

  4. Geolocation of man-made reservoirs across terrains of varying complexity using GIS

    Science.gov (United States)

    Mixon, D.M.; Kinner, D.A.; Stallard, R.F.; Syvitski, J.P.M.

    2008-01-01

    The Reservoir Sedimentation Survey Information System (RESIS) is one of the world's most comprehensive databases of reservoir sedimentation rates, comprising nearly 6000 surveys for 1819 reservoirs across the continental United States. Sediment surveys in the database date from 1904 to 1999, though more than 95% of surveys were entered prior to 1980, making RESIS largely a historical database. The use of this database for large-scale studies has been limited by the lack of precise coordinates for the reservoirs. Many of the reservoirs are relatively small structures and do not appear on current USGS topographic maps. Others have been renamed or have only approximate (i.e. township and range) coordinates. This paper presents a method scripted in ESRI's ARC Macro Language (AML) to locate the reservoirs on digital elevation models using information available in RESIS. The script also delineates the contributing watersheds and compiles several hydrologically important parameters for each reservoir. Evaluation of the method indicates that, for watersheds larger than 5 km2, the correct outlet is identified over 80% of the time. The importance of identifying the watershed outlet correctly depends on the application. Our intent is to collect spatial data for watersheds across the continental United States and describe the land use, soils, and topography for each reservoir's watershed. Because of local landscape similarity in these properties, we show that choosing the incorrect watershed does not necessarily mean that the watershed characteristics will be misrepresented. We present a measure termed terrain complexity and examine its relationship to geolocation success rate and its influence on the similarity of nearby watersheds. ?? 2008 Elsevier Ltd. All rights reserved.

  5. Assessing ways to combat eutrophication in a Chinese drinking water reservoir using SWAT

    DEFF Research Database (Denmark)

    Nielsen, Anders; Trolle, Dennis; Me, W

    2013-01-01

    both point sources and surface activities within the watershed of a reservoir. We expanded the ordinary Soil Water Assessment Tool – (SWAT) with a widely used empirical equation to estimate total phosphorus (TP) concentrations in lakes and reservoirs. Subsequently, we examined the effects of changes...... model performance and nutrient transport pathways, which are challenged by a complex artificially altered water infrastructure in the form of ditches, channels and ponds in monsoon-influenced subtropical watersheds....

  6. Radioactive fallout reconstruction from contemporary measurements of reservoir sediments

    International Nuclear Information System (INIS)

    Krey, P.W.; Heit, M.; Miller, K.M.

    1990-01-01

    The temporal history of atmospheric deposition to a watershed area can be preserved in the sediment of a lake or reservoir that is supplied by the watershed. The 137 Cs and isotopic Pu concentrations with depth were determined in the sediments of two reservoirs, Enterprise and Deer Creek, which are located in widely separated regions of the state of Utah. Our data not only reconstruct the history of the total radioactive fallout in the area, but also permit estimating the contributions from global sources and from the Nevada Test Site detonations in the 1950s

  7. Climate variability and sedimentation of a hydropower reservoir

    International Nuclear Information System (INIS)

    Riedel, M.

    2008-01-01

    This presentation discussed a large-scale watershed and reservoir sedimentation model developed to predict potential sedimentation scenarios for a large hydroelectric power project located in the central Appalachians. The geographic information system (GIS) watershed model was calibrated using observed long-term meteorological and hydrological data. Potential development scenarios were then used to construct future watershed land cover scenarios. Future climate change regimes and precipitation and temperature pattern shifts were identified using climatic variability and potential change analyses. Results of the study were then forecast for a period of 50 years and used to develop sediment yield regimes for the project's reservoir. The model was validated using reservoir and fields studies for watershed, river, and reservoir hydrodynamics. The resulting 3-D hydrological sedimentation model was then used to forecast changes in river sedimentation and storage capacity under various future climate scenarios. Results of the study showed the development of unique zones of advancing sediment deltas and temporary storage areas. Warmer and wetter scenarios produced sedimentation impacts similar to scenarios without climatic change. It was concluded that results of the analyses will be used to help reduce future soil losses in the reservoir. tabs., figs

  8. Status and trends of land change in the Midwest–South Central United States—1973 to 2000

    Science.gov (United States)

    Auch, Roger F.; Karstensen, Krista A.; Auch, Roger F.; Karstensen, Krista A.

    2015-12-10

    U.S. Geological Survey (USGS) Professional Paper 1794–C is the third in a four-volume series on the status and trends of the Nation’s land use and land cover, providing an assessment of the rates and causes of land-use and land-cover change in the Midwest–South Central United States between 1973 and 2000. Volumes A, B, and D provide similar analyses for the Western United States, the Great Plains of the United States, and the Eastern United States, respectively. The assessments of land-use and land-cover trends are conducted on an ecoregion-by-ecoregion basis, and each ecoregion assessment is guided by a nationally consistent study design that includes mapping, statistical methods, field studies, and analysis. Individual assessments provide a picture of the characteristics of land change occurring in a given ecoregion; in combination, they provide a framework for understanding the complex national mosaic of change and also the causes and consequences of change. Thus, each volume in this series provides a regional assessment of how (and how fast) land use and land cover are changing, and why. The four volumes together form the first comprehensive picture of land change across the Nation.Geographic understanding of land-use and land-cover change is directly relevant to a wide variety of stakeholders, including land and resource managers, policymakers, and scientists. The chapters in this volume present brief summaries of the patterns and rates of land change observed in each ecoregion in the Midwest–South Central United States, together with field photographs, statistics, and comparisons with other assessments. In addition, a synthesis chapter summarizes the scope of land change observed across the entire Midwest–South Central United States. The studies provide a way of integrating information across the landscape, and they form a critical component in the efforts to understand how land use and land cover affect important issues such as the provision of

  9. Farm-level risk factors for the occurrence, new infection or persistence of tuberculosis in cattle herds from South-Central Spain.

    Science.gov (United States)

    Martínez-López, B; Barasona, J A; Gortázar, C; Rodríguez-Prieto, V; Sánchez-Vizcaíno, J M; Vicente, J

    2014-10-01

    Eradication of tuberculosis (TB) in cattle is a priority in the EU. However, and despite the resources invested, TB eradication is still a goal yet to be accomplished. As a consequence, the identification of risk factors contributing to TB transmission and persistence is key to a better understand and, ultimately, more cost-effectively control and eradicate this complex zoonotic disease worldwide. This study aimed to identify the factors contributing to the TB occurrence, new infection, and persistence in one of the most TB-prevalent regions in the South-Central part of Spain (SCS), Ciudad Real (CR), and for which high quality and detailed information on cattle and wild ungulate demographics, management, and sanitary status was available for up to 5 years (2007-2011). Multilevel logistic modeling was used for this purpose. Results of this study revealed that the risk for TB (occurrence, new infection, and/or persistence) in cattle herds from CR is related to TB-persistence on farm in previous years, extensive production systems (beef and bullfighting being more risky that dairy) and large farm in terms of cattle number. Also, the presence and proximity of fenced hunting estates (which are usually intensively managed) significantly contributed to the risk of TB occurrence and persistence in CR. This association suggests that wild ungulates may play a role as TB-reservoirs and transmit TB to cattle in the CR, a region where TB is endemic and is associated with extensive farming of beef cattle. To the best of author's knowledge this is the first study to (i) evaluate the wild ungulate-domestic interface at a farm level using detailed information over an extensive region and period of time (2007-2011) and (ii) to identify a direct association between TB in cattle and the proximity and management practices of wild ungulates. Methods and results presented here may support policies to better prevent and control TB in the SCS and in other regions/countries with similar

  10. Effects of ancient porosity and permeability on formation of sedimentary dolomites: Devonian Jefferson Formation (Frasnian), south-central Montana

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T.M.; Dorobek, S.L.

    1987-08-01

    Petrographic and geochemical evidence indicates that multiple dolomitization and dolomite stabilization events affected the Devonian Jefferson Formation (Frasnian) in south-central Montana. Several types of dolomite occur, defined by cathodoluminescence: nonzoned, dully luminescent subhedral-anhedral mosaics (most common), euhedral nonzoned and zoned dolomites, zoned dolomite cements, and irregularly luminescent dolomites (dully luminescent with irregularly luminescent regions). The irregularly luminescent fabrics probably represent partial replacement of early dolomite phases with later dolomite phases. Nonzoned, Ca-enriched, euhedral dolomites occur in calcite-cemented, coarse-grained limestone layers. These permeable layers probably were conduits for early meteoric waters, that occluded porosity in the limestones and prevented later dolomite stabilization. Irregularly luminescent dolomites are interpreted as intermediate fabrics in the dolomite stabilization process. Later calcite cements which occlude intercrystalline porosity prevented further dolomite replacement. Total recrystallization of remaining dolomites and formation of final dully luminescent mosaics occurred prior to brecciation and stylolitization.

  11. Specialized consulting in radiological safety to the south central hospital of high specialty, PEMEX. VI. December of 2001

    International Nuclear Information System (INIS)

    Angeles C, A.; Vizuet G, J.; Benitez S, J.A.; Garcia A, J.; Rodriguez A, F.

    2002-01-01

    It is a report of a specialized consulting in radiological safety that to be carried the ININ to PEMEX for the South Central Hospital of High Specialty, to maintain the sanitary license for the use of X-ray equipment of medical diagnostic, and guarantee these services with a program of quality assurance. To give fulfilment to that requests it is programmed a technical assistance monthly, with reports of results during the development of the service. In this document it is carried a report of the advances and results in the month of december of the 2001, where the following documents are analyzed: Manual of radiological safety, program of quality assurance, operation procedures, procedure of maintenance team, procedure of medical radiological control of the specialized personnel; also are annotate the obtained results and their observations. (Author)

  12. Characterizing the subsurface geology in and around the U.S. Army Camp Stanley Storage Activity, south-central Texas

    Science.gov (United States)

    Blome, Charles D.; Clark, Allan K.

    2018-02-15

    Several U.S. Geological Survey projects, supported by the National Cooperative Geologic Mapping Program, have used multi-disciplinary approaches over a 14-year period to reveal the surface and subsurface geologic frameworks of the Edwards and Trinity aquifers of central Texas and the Arbuckle-Simpson aquifer of south-central Oklahoma. Some of the project achievements include advancements in hydrostratigraphic mapping, three-dimensional subsurface framework modeling, and airborne geophysical surveys as well as new methodologies that link geologic and groundwater flow models. One area where some of these milestones were achieved was in and around the U.S. Army Camp Stanley Storage Activity, located in north­western Bexar County, Texas, about 19 miles north­west of downtown San Antonio.

  13. Heat Flow and Geothermal Potential in the South-Central United States

    International Nuclear Information System (INIS)

    Negraru, Petru T.; Blackwell, David D.; Erkan, Kamil

    2008-01-01

    Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150 deg. C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort Worth Basins are below 50 mW/m 2 while, in the frontal zone of the belt, they can exceed 60 mW/m 2 . Further east, along the Balcones fault system the heat flow is in general higher than 55 mW/m 2 . The eastern most heat flow sites are in Louisiana and they show very high heat flow (over 80 mW/m 2 ), which is associated with the apparently highly radioactive basement of the Sabine uplift. The geothermal resource in this area is large and diverse, and can be divided in high grade (temperature above 150 deg. C) convective systems, conductive based enhanced geothermal systems and geothermal/geopressured systems. One of the most attractive areas east of the cordillera extends from eastern Texas across Louisiana and Arkansas to western Mississippi. Here temperatures reach exploitation range at depths below 4 km, and tapping such a resource from shut in hydrocarbon fields is relatively easy. The initial costs of the development can be greatly reduced if existing hydrocarbon infrastructure is used, and therefore using shut-in hydrocarbon fields for geothermal purposes should not be neglected

  14. Bird Diversity and Structure in Different Land-use Types in Lowland South-Central Mindanao, Philippines.

    Science.gov (United States)

    Tanalgo, Krizler Cejuela; Pineda, John Arislyn Fuentes; Agravante, Maricel Estolloso; Amerol, Zabide Mamalo

    2015-12-01

    Birds are crucial to maintaining the balance of many ecosystems by providing various ecological services. The diversity of birds and their feeding guilds in different land-use types were investigated in south-central Mindanao to elucidate the effect of disturbance and habitat modification on bird communities. Point count method was employed to identify birds in three habitat types: i) agroforests; ii) ricefields; iii) roads and heavily disturbed areas. A total of 1114 bird sightings were recorded that included 33 species of 24 families; of these, 3 were Philippine endemics, and 5 were migrant species. Among all of the habitat types, the highest species diversity was found in agroforests (1/D = 16.148), and the lowest was recorded from roads and heavily disturbed habitats. The species composition of agroforests was more similar to ricefields than to areas with high levels of disturbance, such as roads. The characteristic of the vegetation and the availability of food resources may be vital to the diversity of birds in every habitat as evidenced by the high species richness of frugivores and insectivores in agroforests and ricefields, respectively, where food source is largely available. The observation of Streptopelia tranquebarica was a new record for Mindanao, and it was particularly sighted in ricefields. Therefore, this study indicates that land-use change and modification may alter bird diversity structure, and the maintenance of the vegetation in land-use types as food and resource, and as habitat is essential to the conservation of the native and ecologically-important bird species in south-central Mindanao.

  15. Prevalence and risk factors for Leptospira spp. in cattle herds in the south central region of Paraná state

    Directory of Open Access Journals (Sweden)

    Vanessa Y Hashimoto

    2012-02-01

    Full Text Available The aim of this study was to determine the prevalence of anti-Leptospira spp. antibodies and the risk factors for Leptospira spp. infection in breeding cattle herds in the south central region of Paraná state. It was based on the statistic delineation/serological samples and information regarding the selected farms employed in the study of bovine brucellosis for Paraná state in the context of National Program for Control and Eradication of Brucellosis and Tuberculosis. A total of 1.880 females aged >24 months from 274 non vaccinated herds were studied. Serum samples were tested for antibodies against Leptospira spp. using microscopic agglutination test (MAT with 22 Leptospira serovars. The epidemiological questionnaire was applied on all the selected farms and aimed to obtain epidemiological data. Hundred eighty one of 274 herds were positive for Leptospira spp./presenting prevalence of positive herds of 66.06% (IC95%=60.12-71,65%. Presence of >43 cattle (OR=3.120; IC=1.418-6.867/animal purchase (OR=2.010; IC=1.154-3.500/rent of pastures (OR=2.925; IC=1.060-8.068 and presence of maternity paddock (OR=1.981; IC=1,068-3,676 were identified as risk factors for leptospirosis due to any serovar in the multivariate logistic regression. Risk factors for leptospirosis due to serovar Hardjo were presence of >43 cattle (OR=3.622; IC=1.512-8,677/animal purchase (OR=3.143; IC=1.557-6.342/rent of pastures (OR=4.070; IC=1.370-12.087 and presence of horses (OR=2.981; IC=1.321-6.726. These results indicate that Leptospira spp. infection is widespread in the south central region of Paraná state and that factors related to the herd characteristic and management are associated with the infection.

  16. Dental caries among children visiting a mobile dental clinic in South Central Kentucky: a pooled cross-sectional study.

    Science.gov (United States)

    Dawkins, Erika; Michimi, Akihiko; Ellis-Griffith, Gregory; Peterson, Tina; Carter, Daniel; English, Gary

    2013-05-02

    Dental caries is one of the most common chronic childhood diseases affecting a large portion of children in the United States. The prevalence of childhood dental caries in Kentucky is among the highest in the nation. The purposes of this study are to (1) compare sociodemographic differences between caries and no caries groups and (2) investigate factors associated with untreated dental caries among children who visited a mobile dental clinic in South Central Kentucky. Study subjects were children aged 6 to 15 years who participated in the school-based dental sealant program through the mobile dental clinic operated by the Institute for Rural Health at Western Kentucky University between September 2006 and May 2011 (n = 2,453). Descriptive statistics were calculated for sociodemographic factors (age, gender, race/ethnicity, insurance status, and urban versus rural residential location) and caries status. We used chi-square tests to compare sociodemographic differences of children stratified by caries and no caries status as well as three levels of caries severity. We developed a logistic regression model to investigate factors associated with untreated dental caries while controlling for sociodemographic characteristics. The proportion of children having untreated dental caries was 49.7% and the mean number of untreated dental caries was 2.0. The proportion of untreated dental caries was higher in older children, children with no insurance and living in rural residential locations, and caries severity was also higher in these groups. Odds ratio indicated that older ages, not having private insurance (having only public, government-sponsored insurance or no insurance at all) and rural residential location were associated with having untreated dental caries after controlling for sociodemographic characteristics of children. Untreated dental caries was more likely to be present in older children living in rural areas without insurance. Health interventionists may use

  17. Risk Analysis of Extreme Rainfall Effects on the Shihmen Reservoir

    Science.gov (United States)

    Ho, Y.; Lien, W.; Tung, C.

    2009-12-01

    Typhoon Morakot intruded Taiwan during 7th and 8th of August 2009, brought about 2,700 mm of total rainfall which caused serious flood and debris to the southern region of Taiwan. One of the serious flooded areas is in the downstream of Zengwen reservoir. People believed that the large amount of floodwater released from Zengwen reservoir led to the severe inundation. Therefore, the Shihmen reservoir is one of the important reservoirs in northern Taiwan. The Taipei metropolis, which is in downstream of Shihmen reservoir, is the political and economical center of Taiwan. If heavy rainfall as those brought by Typhoon Marakot falls in the Shihmen reservoir watershed, it may create a bigger disaster. This study focused on the impacts of a typhoon, like Morakot, in Shihmen reservoir. The hydrological model is used to simulate the reservoir inflows under different rainfall conditions. The reservoir water balance model is developed to calculate reservoir’s storage and outflows under the inflows and operational rules. The ability of flood mitigation is also evaluated. Besides, the released floodwater from reservoir and the inflows from different tributaries are used to determine whether or not the river stage will overtop levee. Also, the maximum released floodwater and other inflows which could lead to damages will be stated. Lastly, the criteria of rainfall conditions and initial stages of reservoir will be analyzed in this study.

  18. Historical Changes in Water Quality, Temperature Regimes, and Cyanobacteria Densities of 20 Midwestern USA Reservoirs

    Science.gov (United States)

    Water quality and cyanobacteria densities from 1989-2015 were compiled for 20 Midwestern USA reservoirs. Maximum summer cyanobacteria densities increased over the last 7-15 years of the record, with greatest increases typically observed in reservoirs with low watershed forest cov...

  19. Soil Phosphorus Compositional Characteristics as a Function of Land-Use Practice in the Upper Eau Galle River Watershed, Wisconsin

    National Research Council Canada - National Science Library

    James, William F; Eakin, Harry L; Ruiz, Carlos E; Barko, John W

    2004-01-01

    The purpose of this research was to quantify biologically labile and refractory phosphorus species in source soils of an agricultural watershed that drains into a eutrophic Corps of Engineers reservoir...

  20. Mass transport-related stratal disruption within sedimentary melanges: Examples from the northern Apennines (Italy) and south-central Pyrenees (Spain)

    NARCIS (Netherlands)

    Ogata, Kei; Mutti, Emiliano; Pini, Gian Andrea; Tinterri, Roberto

    2012-01-01

    We report here mass transport-related disruption processes and their artifacts within sedimentary mélanges. The case studies include the early Oligocene wedge-top mass transport deposits in the northern Apennines (Italy) and the Eocene foredeep carbonate megabreccias from the south-central Pyrenees

  1. Mass transport-related stratal disruption within sedimentary m??langes: Examples from the northern Apennines (Italy) and south-central Pyrenees (Spain)

    NARCIS (Netherlands)

    Ogata, Kei; Mutti, Emiliano; Pini, Gian Andrea; Tinterri, Roberto

    2012-01-01

    We report here mass transport-related disruption processes and their artifacts within sedimentary m??langes. The case studies include the early Oligocene wedge-top mass transport deposits in the northern Apennines (Italy) and the Eocene foredeep carbonate megabreccias from the south-central Pyrenees

  2. Reduction of Risk in Exploration and Prospect Generation through a Multidisciplinary Basin-Analysis Program in the South-Central Mid-Continent Region

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Barker, C.; Fite, J.; George, S.; Guo, Genliang; Johnson, W.; Jordan, J., Szpakiewicz, M.; Person, M.; Reeves, T.K.; Safley, E.; Swenson, J.B.; Volk, L.; and Erickson, R.

    1999-04-02

    This report will discuss a series of regional studies that were undertaken within the South-Central Mid-Continent region of the U.S. Coverage is also provided about a series of innovative techniques that were used for this assessment.

  3. Appraisal of the Effectiveness of CODE; The Coordinated Delivery System for the South Central Research Library Council, January to December 1970.

    Science.gov (United States)

    Faibisoff, Sylvia G.

    A major concern of the South Central Research Library Council in establishing an interlibrary loan network was the development of a Coordinated Delivery system (CODE). Several means of delivery were considered--the U.S. mails, commercial trucking (Greyhound, United Parcel Service), and use of the public library system's delivery services. A…

  4. Intermittent reservoir daily-inflow prediction using lumped and ...

    Indian Academy of Sciences (India)

    In this study, multi-linear regression (MLR) approach is used to construct intermittent reservoir daily inflow forecasting system. To illustrate the applicability and effect of using lumped and distributed input data in MLR approach, Koyna river watershed in Maharashtra, India is chosen as a case study. The results are also ...

  5. The invasive species Ulex europaeus (Fabaceae) shows high dynamism in a fragmented landscape of south-central Chile.

    Science.gov (United States)

    Altamirano, Adison; Cely, Jenny Paola; Etter, Andrés; Miranda, Alejandro; Fuentes-Ramirez, Andres; Acevedo, Patricio; Salas, Christian; Vargas, Rodrigo

    2016-08-01

    Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account

  6. Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

    Science.gov (United States)

    Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

    2010-05-01

    Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

  7. Using Annual Landsat Time Series for the Detection of Dry Forest Degradation Processes in South-Central Angola

    Directory of Open Access Journals (Sweden)

    Anne Schneibel

    2017-08-01

    Full Text Available Dry tropical forests undergo massive conversion and degradation processes. This also holds true for the extensive Miombo forests that cover large parts of Southern Africa. While the largest proportional area can be found in Angola, the country still struggles with food shortages, insufficient medical and educational supplies, as well as the ongoing reconstruction of infrastructure after 27 years of civil war. Especially in rural areas, the local population is therefore still heavily dependent on the consumption of natural resources, as well as subsistence agriculture. This leads, on one hand, to large areas of Miombo forests being converted for cultivation purposes, but on the other hand, to degradation processes due to the selective use of forest resources. While forest conversion in south-central rural Angola has already been quantitatively described, information about forest degradation is not yet available. This is due to the history of conflicts and the therewith connected research difficulties, as well as the remote location of this area. We apply an annual time series approach using Landsat data in south-central Angola not only to assess the current degradation status of the Miombo forests, but also to derive past developments reaching back to times of armed conflicts. We use the Disturbance Index based on tasseled cap transformation to exclude external influences like inter-annual variation of rainfall. Based on this time series, linear regression is calculated for forest areas unaffected by conversion, but also for the pre-conversion period of those areas that were used for cultivation purposes during the observation time. Metrics derived from linear regression are used to classify the study area according to their dominant modification processes. We compare our results to MODIS latent integral trends and to further products to derive information on underlying drivers. Around 13% of the Miombo forests are affected by degradation

  8. A seismic case study of salt dissolution and subsidence in response to regional deformation, south-central Alberta

    Science.gov (United States)

    Anderson, Neil L.; Williams, R. Shawn; Hinds, Ronald C.

    1996-04-01

    Bedded rock salt with a net thickness of about 40 m was deposited uniformly within the Famennian Wabamun Group in the Stettler South study area (T33-34, R18-21W4M) of south-central Alberta. Subsequent to deposition, this original rock salt was leached to the extent that it is preserved now as irregular-shaped bodies of widely differing areal extent and thickness. In the immediate study area, dissolution was initiated by regional deformation during the mid-Late Cretaceous, and accentuated thereafter by various large-scale processes including glaciation. Seismic data illustrate that at least some salt-dissolution features in the Stettler South area retain a marked linear orientation (SSW-NNE). In cross section (on west-east oriented seismic lines), these structures are manifested as upward-expanding zones of observable subsidence. These zones of subsidence are characterized by increased structural relief at greater depth (resulting principally to the timing of the leaching, stoping, and lateral strain within post-salt strata), and small-amplitude near-vertical offsets. The character of these subsidence features is consistent with: (1) the onset of dissolution as a result of regional deformation during mid-Late Cretaceous; (2) the plastic deformation (creep) of rock salt; (3) the plastic deformation (on a large scale) and relatively gradual subsidence of the post-salt strata; and (4) accelerated rates of leaching in response to glacial loading and unloading.

  9. Analysis of uranium metallogenic conditions and prospective prognosis on the south-central part of the Xikang-Yunnan Axis

    International Nuclear Information System (INIS)

    Guo Baochi; Qian Farong; Cai Yuqi; Zhang Daishi

    1996-08-01

    Three types of uranium mineralizations (i.e., sandstone type, sodium metasomatite type and Proterozoic epimetamorphic rock type) are distinguished in the south-central part of the Xikang-Yunnan Axis, and their major characteristics are expounded. It is proposed that the Early Proterozoic crust has three elevation stages: primitive old land formation stage, subsidence stage and base mental reconsolidation stage, and that the Middle Proterozoic Kunyang Group is different from typical carbonate-siliceous-politic sedimentary formation which contains many regional uranium-rich horizons. The primitive uranium contents of some rocks in the region have been studied for the first time, and proposed a new knowledge that some relative rocks be recognized as the uranium source rocks of the region. It is pointed out that there are two kinds of hydrothermal alterations, namely, alkaline alteration and acidic alteration, and some areas with development of alkaline alteration have promising uranium-metallogenic potential. As for the U-metallogenic prospect of the region, three conclusions are summarized: (1) This region does not have favourable geologic conditions for the Australian-Canadian type Proterozoic unconformity-related uranium deposit; (2) The Proterozoic unconformity different from that of Australian-Canadian type does not have permission U-metallogenic potential either; (3) The alkaline (sodium) metasomatite type uranium mineralization in the region has some prospecting potential. Therefore on the basis of above-mentioned conclusions five relatively promising uranium-metallogenic prospects are selected. (4 refs.)

  10. Marksmen and the bush: The affective micro-politics of landscape, sex and technology in precolonial South-Central Africa

    Directory of Open Access Journals (Sweden)

    Kathryn M. de Luna

    Full Text Available This essay explores what we can know about the micro-politics of knowledge production using the history of bushcraft as a case study. In many societies in central, eastern and southern Africa, practitioners of technologies undertaken away from the village, in the bush, enjoy a special status. Among the Botatwe-speaking societies of south-central Africa, the status accorded hunters, smelters and other technicians of the bush was crafted in the centuries around the turn of the first millennium by combining old ideas about the blustery character of fame and spirits, and the talk that engendered both with the observation that technicians working in the bush shared a kinesthetic experience of piercing, poking and prodding into action during the generative activities of working smelts and taking down game. Yet the micro-politics of bushcraft knowledge also involved the bodies and feelings of spearmen and metallurgists' wives, lovers, mothers, sisters, and sometimes those of the entire neighbourhood. The invention of a new landscape category, isokwe, and the novel status of these seasonal technicians marks the development of a new kind of virile masculinity available to some men; it was a status with deeply sensuous, material and social meanings for women as well.

  11. Late Paleozoic-Middle Mesozoic uplift rate, cooling rate and geothermal gradient for south-central New York state

    International Nuclear Information System (INIS)

    Johnsson, M.J.

    1985-01-01

    Apatite and zircon crystals were recovered from the Tioga metabentonite (Middle Devonian) at Cherry Valley, New York and from a metabentonite at the top of the Black River Group (Middle Ordovician) at Middleville, New York. Fission-track ages obtained from these minerals are younger than the stratigraphic ages of the units, indicating total or partial resetting of the mineral ages due to thermal annealing of fission-tracks. The age data allow for calculation of a mean uplift rate of 0.019 +- 0.009 mm/yr for the interval 193 to 155 Myr, and a mean cooling rate of 0.38 +- 0.11 0 C/Myr for the interval 354 to 155 Myr. An average geothermal gradient for the interval 354 to 155 Myr is 20 +- 11 C/km. The partially reset zircon age from the Black River metabentonite indicates that the Middle Ordovician rocks of south-central New York have been exposed to temperatures approaching approx. 175 C. This temperature, in conjunction with the calculated geothermal gradient, implies burial of these units to depths approaching 8 km. Such burial suggests that extensive Carboniferous sediments once covered southern New York, and that the Alleghenian Orogeny had a stronger sedimentalogical influence in the northern portion of the Appalachian Basin than has been previously recognized. (author)

  12. Late Holocene Phytolith and Carbon-Isotope Record from a Latosol at Salitre, South-Central Brazil

    Science.gov (United States)

    Alexandre, Anne; Meunier, Jean-Dominique; Mariotti, Andre; Soubies, Francois

    1999-03-01

    The reliability of paleovegetation records inferred from soil phytolith assemblages and SOM (soil organic matter) carbon isotope analysis was examined in light of previous pollen and charcoal reconstructions. The sampled latosol is located in south-central Brazil (Salitre), at a boundary between forest and cerrado. The derived mean age of phytoliths and SOM at each level is the result of a balance between continuous translocation and selective dissolution. It increases with depth in a regular, quantifiable fashion that allows paleoenvironmental interpretation. Phytoliths and SOM tracers first record a savanna phase, associated with the last Holocene long dry period occurring between ca. 5500 and 4500 yr B.P. Two periods of tree community development followed, between ca. 4000 and 3000 and after ca. 970 yr. B.P., leading to the present cerrado/forest association. The dry spell interrupted this trend about 970 ± 60 yr B.P. The second development of woody elements was contemporaneous with an increase in anthropogenic fires. Therefore, climate was more important than fires and human activities in constraining the growth of vegetation during the last nine centuries at Salitre. More generally, despite pedogenic processes, soil phytoliths and δ 13C values of the SOM may be accurate tracers of vegetation changes.

  13. Molecular characterisation of Cryptosporidium spp. in lambs in the South Central region of the State of São Paulo

    Directory of Open Access Journals (Sweden)

    A.S. Zucatto

    2015-04-01

    Full Text Available Considering the proximity of sheep farmers to animals that are possibly diseased or releasing fecal oocysts into the environment and the marked pathogenicity in lambs, the aim of this study was to determine the occurrence and to molecularly characterize the infection by Cryptosporidium spp. in lambs in the South Central region of the state of São Paulo, Brazil. A total of 193 fecal samples were collected from sheep of several breeds, males and females, aged up to one year. Polymerase chain reaction (nested-PCR was used to amplify DNA fragments from the subunit 18S rRNA gene and indicated 15% positivity; sequencing of amplified fragments was possible for 19 samples. Analysis of the obtained sequences showed that the identified species were Cryptosporidium xiaoi for 15 samples, constituting thus the first molecular characterization study of this Cryptosporidium species in Brazil. Cryptosporidium ubiquitum was identified for three samples and Cryptosporidium meleagridis for one sample; the latter two are considered zoonotic species.

  14. Interactions between sedimentary evolution and prehistoric human occupation in the south-central coast of Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo César Fonseca Giannini

    2010-04-01

    Full Text Available Since the beginning of the human occupation in the south-central coast of Santa Catarina State, in Brazil, the articulation between natural and anthropic processes modeled a strongly domesticated landscape, shaped by the massive construction of shell mounds of monumental dimensions and millenarian permanence. In the coastal plain between Passagem da Barra (Laguna District and Figueirinha Lake (Jaguaruna District, 76 sambaquis were mapped, 48 of which have been dated. Systematic site surveys and radiocarbon datings allowed identifying patterns of spatial distribution in sambaquis according to the sedimentary context at the time of construction, stratigraphy and age. Based on these criteria, the following groups were recognized: five geological-geomorphological contexts of location; three stratigraphic patterns; and four phases of sambaqui occupation in the area, based on site number and type of constructive pattern. The model for sedimentary evolution and time-space distribution of sambaquis shows that sites were built in already emerged areas and that inland sites, away from the lagoons, may have not be preserved or they are not exposed due to the continuous sedimentary filling that characterized this region after the maximum Holocene transgression. The crossing of data, here proposed, shows the importance of integral approaches between archaeology and geosciences for the study of landscape evolution.

  15. Fossil beetle evidence for climatic change 18,000-10,000 years B.P. in south-central Chile

    Science.gov (United States)

    Hoganson, J.W.; Ashworth, A.C.

    1992-01-01

    Cold-adapted beetles colonized the lowlands of the Lake Region of south-central Chile following the retreat of glaciers from their maximum extent at about 19,500 yr B.P. The beetle fauna from 18,000 to 14,000 yr B.P. was characterized by species of moorland habitats. This fauna was species-poor compared to later faunas of the postglacial interval. By 14,000 yr B.P. arboreal species were replacing species of open habitats, reflecting a change toward a warmer climate. By about 12,500 yr B.P. fossil beetle assemblages consisted entirely of rain forest species. The fauna of the postglacial interval was about five times as species-rich as that of the glacial interval. The change in species composition and greater diversity of the beetle fauna was produced by an increase in mean annual temperature estimated to be about 4??-5??C. This was the last major climatic change to affect profoundly the biota of the middle latitudes of South America. The fossil beetle assemblages do not imply a reversal to a colder climate at the time of the European Younger Dryas interval between 11,000 and 10,000 yr B.P. ?? 1992.

  16. Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

    Directory of Open Access Journals (Sweden)

    Teresa A. Newsome

    2012-01-01

    Full Text Available Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximized R2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. Maximum R2 values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

  17. Effects of mercury deposition and coniferous forests on the mercury contamination of fish in the south central United States

    Science.gov (United States)

    Drenner, Ray W.; Chumchal, Matthew M.; Jones, Christina M.; Lehmann, Christopher M.B.; Gay, David A.; Donato, David I.

    2013-01-01

    Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to human and wildlife health. We examined the relationship between Hg deposition, land coverage by coniferous and deciduous forests, and average Hg concentrations in largemouth bass (Micropterus salmoides)-equivalent fish (LMBE) in 14 ecoregions located within all or part of six states in the South Central U.S. In 11 ecoregions, the average Hg concentrations in 35.6-cm total length LMBE were above 300 ng/g, the threshold concentration of Hg recommended by the U.S. Environmental Protection Agency for the issuance of fish consumption advisories. Percent land coverage by coniferous forests within ecoregions had a significant linear relationship with average Hg concentrations in LMBE while percent land coverage by deciduous forests did not. Eighty percent of the variance in average Hg concentrations in LMBE between ecoregions could be accounted for by estimated Hg deposition after adjusting for the effects of coniferous forests. Here we show for the first time that fish from ecoregions with high atmospheric Hg pollution and coniferous forest coverage pose a significant hazard to human health. Our study suggests that models that use Hg deposition to predict Hg concentrations in fish could be improved by including the effects of coniferous forests on Hg deposition.

  18. Saw-tooth structures and curved veins related to folds in the south-central Pyrenees (Spain)

    Science.gov (United States)

    Bastida, F.; Aller, J.; Lisle, R. J.; Bobillo-Ares, N. C.; Menéndez, C. O.

    2012-01-01

    Two generation of folds ( F1 and F2) and associated structures, developed in the Eocene turbidites of the south-central Pyrenees, are analyzed in this paper. F1 folds are close, have sub-horizontal axes and southwards vergence. They have an associated cleavage S1. Competent layers were folded by layer-parallel shortening, tangential longitudinal strain, some possible flexural flow and an obliquely superimposed homogeneous strain due mainly to simple shear. Flexural slip is also an important mechanism in the whole multilayer. F2 folds are gentle and scarce; they fold the S1 cleavage. Among the structures associated with F1 folds, there are sets of veins with curved form in the competent layers. The displacement of each vein gave rise usually to a step in the layer boundary, so that a set of veins produces a structure that is named "saw-tooth structure". The veins initiated as small faults that made flexural slip difficult and gave rise to a concentration of stress on the steps, leading to an opening of the fractures and a propagation of them along a curved path, as suggested by a simple mechanical model. This propagation agrees with finite element models developed by other authors.

  19. Rock-Eval pyrolysis and vitrinite reflectance results from the Sheep Creek 1 well, Susitna basin, south-central Alaska

    Science.gov (United States)

    Stanley, Richard G.; Lillis, Paul G.; Pawlewicz, Mark J.; Haeussler, Peter J.

    2014-01-01

    We used Rock-Eval pyrolysis and vitrinite reflectance to examine the petroleum source potential of rock samples from the Sheep Creek 1 well in the Susitna basin of south-central Alaska. The results show that Miocene nonmarine coal, carbonaceous shale, and mudstone are potential sources of hydrocarbons and are thermally immature with respect to the oil window. In the samples that we studied, coals are more organic-rich and more oil-prone than carbonaceous shales and silty mudstones, which appear to be potential sources of natural gas. Lithologically similar rocks may be present in the deeper parts of the subsurface Susitna basin located west of the Sheep Creek 1 well, where they may have been buried deeply enough to generate oil and (or) gas. The Susitna basin is sparsely drilled and mostly unexplored, and no commercial production of hydrocarbons has been obtained. However, the existence of potential source rocks of oil and gas, as shown by our Rock-Eval results, suggests that undiscovered petroleum accumulations may be present in the Susitna basin.

  20. Random and systematic spatial variability of 137Cs inventories at reference sites in South-Central Brazil

    Directory of Open Access Journals (Sweden)

    Correchel Vladia

    2005-01-01

    Full Text Available The precision of the 137Cs fallout redistribution technique for the evaluation of soil erosion rates is strongly dependent on the quality of an average inventory taken at a representative reference site. The knowledge of the sources and of the degree of variation of the 137Cs fallout spatial distribution plays an important role on its use. Four reference sites were selected in the South-Central region of Brazil which were characterized in terms of soil chemical, physical and mineralogical aspects as well as the spatial variability of 137Cs inventories. Some important differences in the patterns of 137Cs depth distribution in the soil profiles of the different sites were found. They are probably associated to chemical, physical, mineralogical and biological differences of the soils but many questions still remain open for future investigation, mainly those regarding the adsorption and dynamics of the 137Cs ions in soil profiles under tropical conditions. The random spatial variability (inside each reference site was higher than the systematic spatial variability (between reference sites but their causes were not clearly identified as possible consequences of chemical, physical, mineralogical variability, and/or precipitation.

  1. Daily Streamflow Predictions in an Ungauged Watershed in Northern California Using the Precipitation-Runoff Modeling System (PRMS): Calibration Challenges when nearby Gauged Watersheds are Hydrologically Dissimilar

    Science.gov (United States)

    Dhakal, A. S.; Adera, S.

    2017-12-01

    Accurate daily streamflow prediction in ungauged watersheds with sparse information is challenging. The ability of a hydrologic model calibrated using nearby gauged watersheds to predict streamflow accurately depends on hydrologic similarities between the gauged and ungauged watersheds. This study examines daily streamflow predictions using the Precipitation-Runoff Modeling System (PRMS) for the largely ungauged San Antonio Creek watershed, a 96 km2 sub-watershed of the Alameda Creek watershed in Northern California. The process-based PRMS model is being used to improve the accuracy of recent San Antonio Creek streamflow predictions generated by two empirical methods. Although San Antonio Creek watershed is largely ungauged, daily streamflow data exists for hydrologic years (HY) 1913 - 1930. PRMS was calibrated for HY 1913 - 1930 using streamflow data, modern-day land use and PRISM precipitation distribution, and gauged precipitation and temperature data from a nearby watershed. The PRMS model was then used to generate daily streamflows for HY 1996-2013, during which the watershed was ungauged, and hydrologic responses were compared to two nearby gauged sub-watersheds of Alameda Creek. Finally, the PRMS-predicted daily flows between HY 1996-2013 were compared to the two empirically-predicted streamflow time series: (1) the reservoir mass balance method and (2) correlation of historical streamflows from 80 - 100 years ago between San Antonio Creek and a nearby sub-watershed located in Alameda Creek. While the mass balance approach using reservoir storage and transfers is helpful for estimating inflows to the reservoir, large discrepancies in daily streamflow estimation can arise. Similarly, correlation-based predicted daily flows which rely on a relationship from flows collected 80-100 years ago may not represent current watershed hydrologic conditions. This study aims to develop a method of streamflow prediction in the San Antonio Creek watershed by examining PRMS

  2. Size distribution of planktonic autotrophy and microheterotrophy in DeGray Reservoir, Arkansas

    International Nuclear Information System (INIS)

    Kimmel, B.L.; Groeger, A.W.

    1983-01-01

    Naturally occurring assemblages of phytoplankton and bacterioplankton were radiolabelled with sodium 14 C-bicarbonate and sodium 3 H-acetate and size fractionated to determine the size structure of planktonic autotrophy and microheterotrophy in DeGray Reservoir, an oligotrophic impoundment of the Caddo River in south-central Arkansas. Size distributions of autotrophy and microheterotrophy were remarkably uniform seasonally, vertically within the water column, and along the longitudinal axis of the reservoir despite significant changes in environmental conditions. Planktonic autotrophy was dominated by small algal cells with usually >50% of the photosynthetic carbon uptake accounted for by organisms 75% of the planktonic microheterotrophy. Longitudinal patterns in autotrophic and microheterotrophic activities associated with >3-μm and >1-μm size fractions, respectively, suggest an uplake to downlake shift from riverine to lacustrine environmental influences within the reservoir. 83 references, 7 figures

  3. Monitoring Reservoirs Using MERIS And LANDSAT Fused Images : A Case Study Of Polyfitos Reservoir - West Macedonia - Greece

    Science.gov (United States)

    Stefouli, M.; Charou, E.; Vasileiou, E.; Stathopoulos, N.; Perrakis, A.

    2012-04-01

    Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the managers of the reservoirs so as to achieve a common / comprehensive management of a large watershed and reservoir system. At this point Remote Sensing could help as the remotely sensed data are repeatedly and readily available to the end users. Aliakmon is the longest river in Greece, it's length is about 297 km and the surface of the river basin is 9.210 km2.The flow of the river starts from Northwest of Greece and ends in Thermaikos Gulf. The riverbed is not natural throughout the entire route, because constructed dams restrict water and create artificial lakes, such as lake of Polyfitos, that prevent flooding. This lake is used as reservoir, for covering irrigational water needs and the water is used to produce energy from the hydroelectric plant of Public Power Corporation-PPC. The catchment basin of Polyfitos' reservoir covers an area of 847.76 km2. Soil erosion - degradation in the mountainous watershed of streams of Polyfitos reservoir is taking place. It has been estimated that an annual volume of sediments reaching the reservoir is of the order of 244 m3. Geomatic based techniques are used in processing multiple data of the study area. A data inventory was formulated after the acquisition of topographic maps, compilation of geological and hydro-geological maps, compilation of digital elevation model for the area of interest based on satellite data and available maps. It also includes the acquisition of various hydro-meteorological data when available. On the basis of available maps and satellite data, digital elevation models are used in order to delineate the basic sub-catchments of the Polyfytos basin as well as

  4. Origin and character of loesslike silt in unglaciated south-central Yakutia, Siberia, U.S.S.R.

    Science.gov (United States)

    Pewe, Troy Lewis; Journaux, Andre

    1983-01-01

    Loesslike silt mantles upland terraces and low plateaus throughout unglaciated south-central Yakutia but is thickest along the south side of the lower Aldan River valley and the east side of the Lena River valley. The silt is probably loess deposited during glacial advances by winds blowing southward from the Verkhoyansk Range and eastward across the broad vegetation-free flood plain of the braided Lena River. The well-sorted uniform tan silt is well displayed along the Aldan and Lena Rivers; the thickest exposure measured, more than 60 m, is on the Tyungyulyu Terrace on the east side of the Lena River. On the west side of the valley, it is 10-25 m thick but thins rapidly to a featheredge west of Yakutsk. Almost all scarps along the south side of the Aldan River are capped by 10-35 m of silt. The texture and mineral composition of the loess like silt are uniform throughout south-central Yakutia, whether it overlies limestone, poorly consolidated sandstone, alluvium, and glacial outwash. All silt samples examined contained a high percentage of quartz and feldspar. The silt stands in sheer cliffs and is massive, with little or no stratification. The origin of the loesslike silt has been ascribed to disintegration in place of country rock by a marine, estuarine, lacustrine, fluvial, residual, or eolian source, or to a combination of these processes. The marine and estuarine hypotheses have never had strong support, but the lacustrine, fluvial, and residual hypotheses have been advanced by many Soviet workers. The most widely accepted explanation of the origin of the upland silt is that it is a combination of lacustrine and alluvial deposits formed on great flood plains and marshy plains. This origin is unlikely, however, because there are no shorelines, wave-cut beaches, deltas, mudcracks, or ripple marks. Neither distinct stratification nor an appreciable amount of clay exists in the silt. Moreover, there is no definite upper boundary to the deposits, as would be

  5. Toponymic Data Helps to Reveal the Occurrence of Previously Unknown Populations of Wild Zamia pumila L. on Volcanic Substrates in South Central Puerto Rico

    OpenAIRE

    Jaime R. Pagán-Jiménez; Julio C. Lazcano-Lara

    2013-01-01

    This is the first report of the occurrence of wild Zamia pumila L. Zamiaceae populations on various volcanic substrates in the piedmont area of south central Puerto Rico. Data acquisition and its field confirmation were possible after the identification of toponymic names in old and current maps, and historic documents of the island in which one of the indigenous names for the genus (marunguey [marungüey] or marungueyes) has been used for naming some localities. These preliminary data have de...

  6. Legacy K/Ar and 40Ar/39Ar geochronologic data from the Alaska-Aleutian Range batholith of south-central Alaska

    Science.gov (United States)

    Koeneman, Lisa L.; Wilson, Frederic H.

    2018-04-06

    Sample descriptions and analytical data for more than 200 K/Ar and 40Ar/39Ar analyses from rocks of the Alaska-Aleutian Range batholith of south-central Alaska are reported here. Samples were collected over a period of 20 years by Bruce R. Reed and Marvin A. Lanphere (both U.S. Geological Survey) as part of their studies of the batholith.

  7. Surface energy flux consequences of bark beetle outbreaks in the south-central Rockies using MODIS data

    Science.gov (United States)

    Vanderhoof, M. K.; Williams, C. A.

    2012-12-01

    Changes in canopy cover due to disturbance-related mortality have been shown to profoundly impact parameters within the surface energy balance and water budget. A shift in such fluxes can have consequences for surface temperature, cloudiness, run-off and stream flow, forest regeneration and net primary productivity. Current outbreaks of native bark beetles in western North America are some of the largest and most severe in recorded history. In recent outbreaks, bark beetles have reduced the basal area of host-dominated forests by up to 70%; with over-story mortality often exceeding 90% in mature, even-aged stands. The magnitude, frequency and intensity of recent outbreaks have been attributed to warmer summer and winter temperatures and drought conditions as a result of climate change. However, despite the likelihood that canopy mortality from bark beetle attacks will have profound effects on forest albedo and evapotranspiration, consequences for this disturbance type remain largely un-documented. This study addressed the question: how does a bark beetle outbreak event influence surface albedo and evapotranspiration? Seasonal patterns of surface temperature, albedo, evapotranspiration, and radiative forcing were modeled for lodgepole and ponderosa pine stands by outbreak age using Moderate Resolution Imaging Spectroradiometer (MODIS) data within the south-central Rocky Mountains. Beetle damage data was derived from both field-based plots as well as aerial surveys. The prevalence of bark beetle outbreaks in high-elevation environments, which are exceedingly sensitive to climate change, necessitates the importance of understanding the energy and evapotranspiration consequences of such events.

  8. Petrography and geochemistry of five granitic plutons from south central Uruguay: contribution to the knowledge of the Piedra Alta terrane

    International Nuclear Information System (INIS)

    Preciozzi, F.

    2005-01-01

    Granitoid rocks in south-central Uruguay are largely concentrated in three east-west trending metamorphic belts, known as (from south to north) the Montevideo Belt, the San José Belt and the Arroyo Grande Belt. These belts are separated from one another by intervening bands of gneisses of granitic composition. The whole assemblage, the gneisses as well as the metamorphic belts and their associated granites, collectively constitute the Piedra Alta Terrane. Five of these granite plutons, two from the San José Belt and three from the Arroyo Grande Belt, have been studied in some detail and the chemical composition of 86 samples (major elements as well as a selected suite of trace elements) have been determined. These data, as well as Rb-Sr isotopic data, show that these plutons are typically composite in nature, and that the various units range in age from 1900 Ma to 2500 Ma. The older ages were obtained from the main units of the plutons themselves whereas the younger ages are from late dykes which were emplaced into the plutons and which are clearly not related to them. The plutons are predominantly, but not exclusively, of calc-alkaline affinity and are typically synorogenic whereas the dykes are post-orogenic and are either calc-alkaline or alkaline in composition. These data have been incorporated into a tectonic model for the Piedra Alta Terrane which is considerably different from that heretofore proposed. The essential features of the geological history of the area are: 1) development of an older ''basement'' of granitic gneisses 2) deposition, upon or adjacent to this gneisses basement, of a typical Archean greenstone belt assemblage (no komatiites so far reported) 3) Paleo-proterozoic metamorphism, followed by syn-tectonic to post-tectonic intrusion of the plutonic rocks 4) major tectonic dislocation(s) associated with the Transamazonian orogeny 5) dyke emplacement (post-orogenic to anorogenic) following the Transamazonian orogeny

  9. Northward extension of Carolina slate belt stratigraphy and structure, South-Central Virginia: Results from geologic mapping

    Science.gov (United States)

    Hackley, P.C.; Peper, J.D.; Burton, W.C.; Horton, J. Wright

    2007-01-01

    Geologic mapping in south-central Virginia demonstrates that the stratigraphy and structure of the Carolina slate belt extend northward across a steep thermal gradient into upper amphibolite-facies correlative gneiss and schist. The Neoproterozoic greenschist-facies Hyco, Aaron, and Virgilina Formations were traced northward from their type localities near Virgilina, Virginia, along a simple, upright, northeast-trending isoclinal syncline. This syncline is called the Dryburg syncline and is a northern extension of the more complex Virgilina synclinorium. Progressively higher-grade equivalents of the Hyco and Aaron Formations were mapped northward along the axial trace of the refolded and westwardly-overturned Dryburg syncline through the Keysville and Green Bay 7.5-minute quadrangles, and across the northern end of the Carolina slate belt as interpreted on previous geologic maps. Hyco rocks, including felsic metatuff, metawacke, and amphibolite, become gneisses upgrade with areas of local anatexis and the segregation of granitic melt into leucosomes with biotite selvages. Phyllite of the Aaron Formation becomes garnet-bearing mica schist. Aaron Formation rocks disconformably overlie the primarily felsic volcanic and volcaniclastic rocks of the Hyco Formation as evidenced by repeated truncation of internal contacts within the Hyco on both limbs of the Dryburg syncline at the Aaron-Hyco contact. East-northeast-trending isograds, defined successively by the first appearance of garnet, then kyanite ?? staurolite in sufficiently aluminous rocks, are superposed on the stratigraphic units and synclinal structure at moderate to high angles to strike. The textural distinction between gneisses and identifiable sedimentary structures occurs near the kyanite ?? staurolite-in isograd. Development of the steep thermal gradient and regional penetrative fabric is interpreted to result from emplacement of the Goochland terrane adjacent to the northern end of the slate belt during

  10. The origin of Late Ediacaran post-collisional granites near the Chad Lineament, Saharan Metacraton, South-Central Chad

    Science.gov (United States)

    Shellnutt, J. Gregory; Yeh, Meng-Wan; Lee, Tung-Yi; Iizuka, Yoshiyuki; Pham, Ngoc Ha T.; Yang, Chih-Cheng

    2018-04-01

    The southern Saharan Metacraton is one of the least geologically constrained regions in the world as bedrock exposures are rare. To the west of Lake Fitri near the communities of Ngoura and Moyto in south-central Chad there are two granitic inliers that form a series of lenticular to ellipsoidal low laying hills. Very little is known about the Lake Fitri inliers and their regional correlation to larger massifs in Chad is undetermined. The granites yielded weighted-mean zircon 206Pb/238U ages of 554 ± 8 Ma and 546 ± 8 Ma indicating they were emplaced 45 million years after the cessation of arc-related magmatism and the subsequent collision between the Congo-São Francisco Craton and the Saharan Metacraton. The rocks have distinct groupings of inherited zircons with ages of 580 Ma and 635 Ma suggesting they are at least in part derived by recycling of older crustal rocks. The biotite mineral chemistry, whole rock compositions and petrological modeling indicate the granites were derived by melting of crustal lithologies but the whole rock Nd isotopes (εNd(t) = +1.3-+2.9) are characteristic of a mantle source. The contrasting inheritance-rich nature of the granites with a juvenile Nd isotopic signature is likely due to mixing between magmas derived from juvenile (Neoproterozoic) arc-related crust and asthenospheric magmas. Asthenospheric upwelling was probably a response to post-orogenic lithospheric delamination related to fault movement along the Chad Lineament, a possible extension of the Tcholliré-Banyo shear zone that extended to the interior of the Saharan Metacraton. The implications are that lithospheric delamination may not have occurred immediately after collision but rather propagated along a narrow belt that extended well into the central regions of the Saharan Metacraton.

  11. Persistence of evapotranspiration impacts from mountain pine beetle outbreaks in lodgepole pine forests, south-central Rocky Mountains, USA

    Science.gov (United States)

    Vanderhoof, Melanie; Williams, Christopher

    2014-05-01

    The current extent and high severity (percent tree mortality) of mountain pine beetle outbreaks across western North America have been attributed to regional climate change, specifically warmer summer and winter temperatures and drier summers. These outbreaks are widespread and have potentially persistent impacts on forest evapotranspiration. The few data-driven studies have largely been restricted by the temporal availability of remote sensing products. This study utilized multiple mountain pine beetle outbreak location datasets, both current and historical, within lodgepole pine stands in the south-central Rocky Mountains. The full seasonal evapotranspiration impact of outbreak events for decades after outbreak (0 to 60 years) and the role of outbreak severity in determining that impact were quantified. We found a 30% reduction in evapotranspiration peaking at 14-20 years post-outbreak during the spring snowmelt period, when water was not limited, but a minimal reduction in evapotranspiration during the remainder of the growing season (June - August). We also found a significant increase in evapotranspiration, relative to non-attacked stands, in intermediate aged stands (20-40 years post-disturbance) corresponding with a peak in LAI and therefore transpiration. During the snow-cover months evapotranspiration initially increased with needle fall and snag fall and corresponding increases in albedo and shortwave transmission to the surface. We found that changes in evapotranspiration during all seasons dissipated by 60 years post-attack. MODIS evapotranspiration values responded most strongly to mountain pine beetle driven changes in net radiation or available energy, and vegetation cover (e.g. LAI, fPAR and EVI). It also appears that the post-attack response of evapotranspiration may be sensitive to precipitation patterns and thus the consequences of a disturbance event may depend on the directionality of climate change conditions.

  12. Quantification and regionalization of groundwater recharge in South-Central Kansas: Integrating field characterization, statistical analysis, and GIS

    Science.gov (United States)

    Sophocleous, M.

    2000-01-01

    A practical methodology for recharge characterization was developed based on several years of field-oriented research at 10 sites in the Great Bend Prairie of south-central Kansas. This methodology combines the soil-water budget on a storm-by-storm year-round basis with the resulting watertable rises. The estimated 1985-1992 average annual recharge was less than 50mm/year with a range from 15 mm/year (during the 1998 drought) to 178 mm/year (during the 1993 flood year). Most of this recharge occurs during the spring months. To regionalize these site-specific estimates, an additional methodology based on multiple (forward) regression analysis combined with classification and GIS overlay analyses was developed and implemented. The multiple regression analysis showed that the most influential variables were, in order of decreasing importance, total annual precipitation, average maximum springtime soil-profile water storage, average shallowest springtime depth to watertable, and average springtime precipitation rate. Therefore, four GIS (ARC/INFO) data "layers" or coverages were constructed for the study region based on these four variables, and each such coverage was classified into the same number of data classes to avoid biasing the results. The normalized regression coefficients were employed to weigh the class rankings of each recharge-affecting variable. This approach resulted in recharge zonations that agreed well with the site recharge estimates. During the "Great Flood of 1993," when rainfall totals exceeded normal levels by -200% in the northern portion of the study region, the developed regionalization methodology was tested against such extreme conditions, and proved to be both practical, based on readily available or easily measurable data, and robust. It was concluded that the combination of multiple regression and GIS overlay analyses is a powerful and practical approach to regionalizing small samples of recharge estimates.

  13. Structured decision making for conservation of bull trout (Salvelinus confluentus) in Long Creek, Klamath River Basin, south-central Oregon

    Science.gov (United States)

    Benjamin, Joseph R.; McDonnell, Kevin; Dunham, Jason B.; Brignon, William R.; Peterson, James T.

    2017-06-21

    With the decline of bull trout (Salvelinus confluentus), managers face multiple, and sometimes contradictory, management alternatives for species recovery. Moreover, effective decision-making involves all stakeholders influenced by the decisions (such as Tribal, State, Federal, private, and non-governmental organizations) because they represent diverse objectives, jurisdictions, policy mandates, and opinions of the best management strategy. The process of structured decision making is explicitly designed to address these elements of the decision making process. Here we report on an application of structured decision making to a population of bull trout believed threatened by high densities of nonnative brook trout (S. fontinalis) and habitat fragmentation in Long Creek, a tributary to the Sycan River in the Klamath River Basin, south-central Oregon. This involved engaging stakeholders to identify (1) their fundamental objectives for the conservation of bull trout, (2) feasible management alternatives to achieve their objectives, and (3) biological information and assumptions to incorporate in a decision model. Model simulations suggested an overarching theme among the top decision alternatives, which was a need to simultaneously control brook trout and ensure that the migratory tactic of bull trout can be expressed. More specifically, the optimal management decision, based on the estimated adult abundance at year 10, was to combine the eradication of brook trout from Long Creek with improvement of downstream conditions (for example, connectivity or habitat conditions). Other top decisions included these actions independently, as well as electrofishing removal of brook trout. In contrast, translocating bull trout to a different stream or installing a barrier to prevent upstream spread of brook trout had minimal or negative effects on the bull trout population. Moreover, sensitivity analyses suggested that these actions were consistently identified as optimal across

  14. Dublin South Central (DSC)

    LENUS (Irish Health Repository)

    O'Gorman, Clodagh S M

    2010-12-01

    Children who appear healthy, even if they have one or more recognized cardiovascular risk factors, do not generally have outcomes of cardiovascular or other vascular disease during childhood. Historically, pediatric medicine has not aggressively screened for or treated cardiovascular risk factors in otherwise healthy children. However, studies such as the P-Day Study (Pathobiological Determinants of Atherosclerosis in Youth), and the Bogalusa Heart Study, indicate that healthy children at remarkably young ages can have evidence of significant atherosclerosis. With the increasing prevalence of pediatric obesity, can we expect more health problems related to the consequences of pediatric dyslipidemia, hypertriglyceridemia, and atherosclerosis in the future? For many years, medications have been available and used in adult populations to treat dyslipidemia. In recent years, reports of short-term safety of some of these medications in children have been published. However, none of these studies have detailed long-term follow-up, and therefore none have described potential late side-effects of early cholesterol-lowering therapy, or potential benefits in terms of reduction of or delay in cardiovascular or other vascular end-points. In 2007, the American Heart Association published a scientific statement on the use of cholesterol-lowering therapy in pediatric patients. In this review paper, we discuss some of the current literature on cholesterol-lowering therapy in children, including the statins that are currently available for use in children, and some of the cautions with using these and other cholesterol-lowering medications. A central tenet of this review is that medications are not a substitute for dietary and lifestyle interventions, and that even in children on cholesterol-lowering medications, physicians should take every opportunity to encourage children and their parents to make healthy diet and lifestyle choices.

  15. An adaptive watershed management assessment based on watershed investigation data.

    Science.gov (United States)

    Kang, Min Goo; Park, Seung Woo

    2015-05-01

    The aim of this study was to assess the states of watersheds in South Korea and to formulate new measures to improve identified inadequacies. The study focused on the watersheds of the Han River basin and adopted an adaptive watershed management framework. Using data collected during watershed investigation projects, we analyzed the management context of the study basin and identified weaknesses in water use management, flood management, and environmental and ecosystems management in the watersheds. In addition, we conducted an interview survey to obtain experts' opinions on the possible management of watersheds in the future. The results of the assessment show that effective management of the Han River basin requires adaptive watershed management, which includes stakeholders' participation and social learning. Urbanization was the key variable in watershed management of the study basin. The results provide strong guidance for future watershed management and suggest that nonstructural measures are preferred to improve the states of the watersheds and that consistent implementation of the measures can lead to successful watershed management. The results also reveal that governance is essential for adaptive watershed management in the study basin. A special ordinance is necessary to establish governance and aid social learning. Based on the findings, a management process is proposed to support new watershed management practices. The results will be of use to policy makers and practitioners who can implement the measures recommended here in the early stages of adaptive watershed management in the Han River basin. The measures can also be applied to other river basins.

  16. Stormwater Impaired Watersheds

    Data.gov (United States)

    Vermont Center for Geographic Information — Stormwater impaired watersheds occuring on both the Priority Waters (Part D - Completed TMDL) and 303(d) list of waters (Part A - need TMDL) The Vermont State...

  17. Watershed Planning Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  18. Healthy Watersheds Protection

    Science.gov (United States)

    ... aquatic and riparian habitats in the longitudinal, lateral, vertical, and temporal dimensions helps ensure the flow of ... live there. A watershed – the land area that drains to a stream, lake or river – affects the ...

  19. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  20. Impacts of land use change and climate variations on annual inflow into the Miyun Reservoir, Beijing, China

    Science.gov (United States)

    Jiangkun Zheng; Ge Sun; Wenhong Li; Xinxiao Yu; Chi Zhang; Yuanbo Gong; Lihua Tu

    2016-01-01

    The Miyun Reservoir, the only surface water source for Beijing city, has experienced water supply decline in recent decades. Previous studies suggest that both land use change and climate contribute to the changes of water supply in this critical watershed. However, the specific causes of the decline in the Miyun Reservoir are debatable under a non-stationary climate...

  1. Pareja limno-reservoir (Guadalajara, Spain): environmental and hydrologic aspects

    International Nuclear Information System (INIS)

    Molina Navarro, E.; Martinez Perez, S.; Sastre Merlin, A.

    2010-01-01

    The construction of small reservoir on the edge of large ones is an innovative idea designed to counteract some of the negative impacts caused by the construction and use of reservoirs. The denomination Limno-reservoirs is proposed here, as these water bodies are created to maintain a natural lake dynamics. Pareja's limno-reservoir is among the first limno-reservoirs in Spain, and its construction raises some questions about hydrological viability and siltation risk. The proposition of the methodologies to solve them and the evaluation of the first results is the aim of this study. A detailed water balance makes possible to affirm that, in a firs approach, the limno-reservoir is viable from the hydrological point of view, because the Ompolveda basin -Tajo's tributary at Entrepenas reservoir- has enough water resources to guarantee the permanence of the water body, even during dry years. To assess the siltation risk, a soil loss observation network will be monitoring the Ompolveda basin for the next three years to evaluate the net erosion in the watershed and the sediment delivery to the reservoir. (Author)

  2. 75 FR 11837 - Chesapeake Bay Watershed Initiative

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF AGRICULTURE Commodity Credit Corporation Chesapeake Bay Watershed Initiative AGENCY...: Notice of availability of program funds for the Chesapeake Bay Watershed Initiative. SUMMARY: The... through the Chesapeake Bay Watershed Initiative for agricultural producers in the Chesapeake Bay watershed...

  3. Stream, Lake, and Reservoir Management.

    Science.gov (United States)

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  4. Morphological description and ecology of some rare macroalgae in south-central Spanish rivers (Castilla-La Mancha Region

    Directory of Open Access Journals (Sweden)

    Moreno Alcaraz, Jose Luis

    2013-06-01

    Full Text Available The Castilla-La Mancha Region (south-central Spain is scarcely studied in terms of freshwater algae. However, both the implementation of the Water Framework Directive (2000/60/CE and the evaluation of the ecological state of European aquatic ecosystems have increased the intensity and frequency of water body monitoring, including the rivers, lakes and wetlands of this region. Thus, our knowledge on algal biodiversity and the geographical distribution of many species is rapidly increasing. In this study we describe the occurrence, ecological conditions and morphological characteristics of five algal species which are rare at the European level: Nostochopsis lobata Wood ex Bornet & Flahault, Batrachospermum atrum (Hudson Harvey, Chroothece richteriana Hansg., Oocardium stratum Nägeli and Tetrasporidium javanicum Möbius. In addition, we include Hydrurus foetidus (Vill. Trev., a more common alga in Spain, since this is the first record for the region. Finally, we compare morphological and ecological characteristics of the studied populations with other European records.El conocimiento sobre la biodiversidad algal de la región de Castilla-La Mancha, situada en la zona centro-sur de España, es escaso en comparación con el de otras regiones peninsulares. Sin embargo, la aplicación de la Directiva Marco del Agua (2000/60/CE, y la evaluación del estado ecológico de los ecosistemas acuáticos europeos, ha traído consigo un aumento en la frecuencia e intensidad en el muestreo de ríos, lagos y humedales. De esta forma, durante los últimos años se han producido nuevos hallazgos en la región que han permitido ampliar el conocimiento de la biodiversidad de algas así como de la distribución geográfica de muchas de sus especies. En este trabajo se describen las condiciones ecológicas y las características morfológicas de cinco especies que pueden considerarse raras a nivel europeo: Nostochopsis lobata Wood & Bornet & Flahault, Batrachospermum

  5. GPS and Satellite InSAR Observations of Landslide Activity at the Sinking Canyon in South Central Idaho

    Science.gov (United States)

    Aly, M. H.; Glenn, N. F.; Thackray, G. D.

    2014-12-01

    Multiple rotational, transitional, and lateral spread landslides have occurred in south central Idaho where basalt lava flows overly unconsolidated lake and fluvial sediments at the Sinking Canyon. The canyon is about 0.1 km deep and 0.25-1 km wide along a 4-km segment of the Salmon Falls Creek (SFC). Local topography and hydrological conditions are most likely the major triggering factors that have initiated landslides by increasing the gravitational stresses and weakening the canyon wall materials. Landslide activity has created natural dams of SFC, which in turn has resulted in forming large lakes with a potential flooding hazard to life and property downstream. In this study, we use campaign Global Positioning System (GPS) measurements of 2003-2004 and Synthetic Aperture Radar Interferometric (InSAR) data acquired during 1992-2007 by the European radar satellites (ERS-1 and ERS-2) to identify, monitor, and analyze recent landslide activity at SFC. Results show that three main landslides have been active during the period of observation: the Salmon Falls landslide (SFL) that has been first reported in 1999, the historical 1937 landslide, and a third unnamed landslide to the north of the 1937 slide. InSAR measurements indicate that the SFL has been active during the period of our earliest interferogram (1992-1993) whereas the slide head has detached and has moved away from the eastern canyon wall about 3 cm. Over the years, the SFL body and toe have been pushed westward repetitively at rates of about 3-7 cm/yr. The toe is confined by the western canyon wall and thus is pushed upward in some years causing slight uplift (2-3 cm). Our field observations reveal many transverse and radial cracks associated with the deformation pattern caused by recurring motions. The historic 1937 slide is the largest mass wasting and is the least active landslide in the study area. The unnamed slide shows episodic activity with varying rates (0-4 cm/yr) of line-of-sight motions. This

  6. Quality of groundwater and surface water, Wood River Valley, south-central Idaho, July and August 2012

    Science.gov (United States)

    Hopkins, Candice B.; Bartolino, James R.

    2013-01-01

    Residents and resource managers of the Wood River Valley of south-central Idaho are concerned about the effects that population growth might have on the quality of groundwater and surface water. As part of a multi-phase assessment of the groundwater resources in the study area, the U.S. Geological Survey evaluated the quality of water at 45 groundwater and 5 surface-water sites throughout the Wood River Valley during July and August 2012. Water samples were analyzed for field parameters (temperature, pH, specific conductance, dissolved oxygen, and alkalinity), major ions, boron, iron, manganese, nutrients, and Escherichia coli (E.coli) and total coliform bacteria. This study was conducted to determine baseline water quality throughout the Wood River Valley, with special emphasis on nutrient concentrations. Water quality in most samples collected did not exceed U.S. Environmental Protection Agency standards for drinking water. E. coli bacteria, used as indicators of water quality, were detected in all five surface-water samples and in two groundwater samples collected. Some analytes have aesthetic-based recommended drinking water standards; one groundwater sample exceeded recommended iron concentrations. Nitrate plus nitrite concentrations varied, but tended to be higher near population centers and in agricultural areas than in tributaries and less populated areas. These higher nitrate plus nitrite concentrations were not correlated with boron concentrations or the presence of bacteria, common indicators of sources of nutrients to water. None of the samples collected exceeded drinking-water standards for nitrate or nitrite. The concentration of total dissolved solids varied considerably in the waters sampled; however a calcium-magnesium-bicarbonate water type was dominant (43 out of 50 samples) in both the groundwater and surface water. Three constituents that may be influenced by anthropogenic activity (chloride, boron, and nitrate plus nitrite) deviate from this

  7. A new geological framework for south-central Madagascar, and its relevance to the "out-of-Africa" hypothesis

    Science.gov (United States)

    Tucker, R.D.; Roig, J.Y.; Macey, P.H.; Delor, C.; Amelin, Y.; Armstrong, R.A.; Rabarimanana, M.H.; Ralison, A.V.

    2011-01-01

    The Precambrian shield of south-central Madagascar, excluding the Vohibory region, consists of three geologic domains, from north to south: Antananarivo, Ikalamavony-Itremo, and Anosyen-Androyen. The northern Antananarivo domain represents the Neoarchean sector of the Greater Dharwar Craton amalgamated at 2.52-2.48. Ga. The Greater Dharwar Craton is overlain by several groups of Meso- to Neoproterozoic supracrustal rocks (Ambatolampy, Manampotsy, Ampasary, Sahantaha, and Maha Groups) each with a common and diagnostic signature of Paleoproterozoic detrital zircons (2.2-1.8. Ga). The central domain (Ikalamavony-Itremo) consists of two distinct parts. The Itremo Sub-domain, in the east, is a structurally intercalated sequence of Neoarchean gneiss and shallow marine metasedimentary rocks of Paleo-Mesoproterozoic age (Itremo Group), the latter with Paleoproterozoic detrital zircons ranging in age between 2.2 and 1.8. Ga. The Ikalamavony Sub-domain, to the west, contains abundant volcano-clastic metasediments and lesser quartzite (Ikalamavony Group), formed between 1.03. Ga and 0.98. Ga, and intruded by igneous rocks (Dabolava Suite) of Stenian-Tonian age. Structurally intercalated with these are sheets of Neoarchean gneiss (~2.5. Ga) and Neoproterozoic metaclastic rocks (Molo Group). Like the Itremo Group, quartzite of the Ikalamavony Group has detrital zircons of Paleoproterozoic age (2.1-1.8. Ga). The southern domain of Anosyen-Androyen consists of a newly recognized suite of Paleoproterozoic igneous rocks (2.0-1.8. Ga), and stratified supracrustal rocks also having Paleoproterozoic detrital zircons (2.3-1.8. Ga). The contact between the Anosyen-Androyen and Ikalamavony-Itremo domains, formerly known as the Ranotsara-Bongolava shear zone, is a tightly folded and highly flattened boundary that was ductilely deformed in Ediacaran time. It is roughly equivalent to the Palghat-Cauvery shear zone in south India, and it defines approximately the boundary between the Archean

  8. Petrogenesis of incipient charnockite in the Ikalamavony sub-domain, south-central Madagascar: New insights from phase equilibrium modeling

    Science.gov (United States)

    Endo, Takahiro; Tsunogae, Toshiaki; Santosh, M.; Shaji, E.; Rambeloson, Roger A.

    2017-06-01

    Incipient charnockites representing granulite formation on a mesoscopic scale occur in the Ambodin Ifandana area of Ikalamavony sub-domain in south-central Madagascar. Here we report new petrological data from these rocks, and discuss the process of granulite formation on the basis of petrography, mineral equilibrium modeling, and fluid inclusion studies. The incipient charnockites occur as brownish patches, lenses, and layers characterized by an assemblage of biotite + orthopyroxene + K-feldspar + plagioclase + quartz + magnetite + ilmenite within host orthopyroxene-free biotite gneiss with an assemblage of biotite + K-feldspar + plagioclase + quartz + magnetite + ilmenite. Lenses and layers of calc-silicate rock (clinopyroxene + garnet + plagioclase + quartz + titanite + calcite) are typically associated with the charnockite. Coarse-grained charnockite occurs along the contact between the layered charnockite and calc-silicate rock. The application of mineral equilibrium modeling on the mineral assemblages in charnockite and biotite gneiss employing the NCKFMASHTO system as well as fluid inclusion study on coarse-grained charnockite defines a P-T range of 8.5-10.5 kbar and 880-900 °C, which is nearly consistent with the inferred P-T condition of the Ikalamavony sub-domain (8.0-10.5 kbar and 820-880 °C). The result of T versus H2O activity (a(H2O)) modeling demonstrates that orthopyroxene-bearing assemblage in charnockite is stable under relatively low a(H2O) condition of 0.42-0.43, which is consistent with the popular models of incipient-charnockite formation related to the lowering of water activity and stabilization of orthopyroxene through dehydration of biotite. The occurrence of calc-silicate rocks adjacent to the charnockite suggests that the CO2-bearing fluid that caused dehydration and incipient-charnockite formation might have been derived through decarbonation of calc-silicate rocks during the initial stage of decompression slightly after the peak

  9. Human Settlements in the South-Central U.S., Viewed at Night from the International Space Station

    Science.gov (United States)

    Dawson, Melissa; Evans, Cynthia; Stefanov, William; Wilkinson, M. Justin; Willis, Kimberly; Runco, Susan

    2012-01-01

    A recent innovation of astronauts observing Earth from the International Space Station (ISS) is documenting human footprints by photographing city lights at night time. One of the earliest night-time images from the ISS was the US-Mexico border at El Paso-Ciudad Juarez. The colors, patterns and density of city lights document the differences in the cultural settlement patterns across the border region, as well as within the urban areas themselves. City lights help outline the most populated areas in settlements around the world, and can be used to explore relative population densities, changing patterns of urban/suburban development, transportation networks, spatial relationship to geographic features, and more. The data also provides insight into parameters such as surface roughness for input into local and regional climate modeling and studies of light pollution. The ground resolution of night-time astronaut photography from the ISS is typically an order of magnitude greater than current Defense Meteorological Satellite Program (DMSP) data, and therefore can serve as a "zoom lens" for selected urban areas. Current handheld digital cameras in use on the ISS, optimized for greater light sensitivity, provide opportunities to obtain new detailed imagery of atmospheric phenomena such as airglow, aurora, and noctilucent clouds in addition to documenting urban patterns. ISS astronauts have taken advantage of increasingly sensitive digital cameras to document the world at night in unprecedented detail. In addition, the capability to obtain time-lapse imagery from fixed cameras has been exploited to produce dynamic videos of both changing surface patterns around the world and atmospheric phenomena. We will profile some spectacular images of human settlements over the South-Central U.S., and contrast with other images from around the world. More data can be viewed at http://eol.jsc.nasa.gov/Videos/CrewEarthObservationsVideos/. US-Mexico border is obvious by the different

  10. Emission factors of particulate matter, polycyclic aromatic hydrocarbons, and levoglucosan from wood combustion in south-central Chile.

    Science.gov (United States)

    Jimenez, Jorge; Farias, Oscar; Quiroz, Roberto; Yañez, Jorge

    2017-07-01

    In south-central Chile, wood stoves have been identified as an important source of air pollution in populated areas. Eucalyptus (Eucalyptus globulus), Chilean oak (Nothofagus oblique), and mimosa (Acacia dealbata) were burned in a single-chamber slow-combustion wood stove at a controlled testing facility located at the University of Concepción, Chile. In each experiment, 2.7-3.1 kg of firewood were combusted while continuously monitoring temperature, exhaust gases, burn rate, and collecting particulate matter samples in Teflon filters under isokinetic conditions for polycyclic aromatic hydrocarbon and levoglucosan analyses. Mean particulate matter emission factors were 2.03, 4.06, and 3.84 g/kg dry wood for eucalyptus, oak, and mimosa, respectively. The emission factors were inversely correlated with combustion efficiency. The mean emission factors of the sums of 12 polycyclic aromatic hydrocarbons in particle phases were 1472.5, 2134.0, and 747.5 μg/kg for eucalyptus, oak, and mimosa, respectively. Fluoranthene, pyrene, benzo[a]anthracene, and chrysene were present in the particle phase in higher proportions compared with other polycyclic aromatic hydrocarbons that were analyzed. Mean levoglucosan emission factors were 854.9, 202.3, and 328.0 mg/kg for eucalyptus, oak, and mimosa, respectively. Since the emissions of particulate matter and other pollutants were inversely correlated with combustion efficiency, implementing more efficient technologies would help to reduce air pollutant emissions from wood combustion. Residential wood burning has been identified as a significant source of air pollution in populated areas. Local wood species are combusted for home cooking and heating, which releases several toxic air pollutants, including particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons. Air pollutant emissions depend on the type of wood and the technology and operational conditions of the wood stove. A better understanding of emissions from

  11. Come rain or shine: Multi-model Projections of Climate Hazards affecting Transportation in the South Central United States

    Science.gov (United States)

    Mullens, E.; Mcpherson, R. A.

    2016-12-01

    This work develops detailed trends in climate hazards affecting the Department of Transportation's Region 6, in the South Central U.S. Firstly, a survey was developed to gather information regarding weather and climate hazards in the region from the transportation community, identifying key phenomena and thresholds to evaluate. Statistically downscaled datasets were obtained from the Multivariate Adaptive Constructed Analogues (MACA) project, and the Asynchronous Regional Regression Model (ARRM), for a total of 21 model projections, two coupled model intercomparisons (CMIP3, and CMIP5), and four emissions pathways (A1Fi, B1, RCP8.5, RCP4.5). Specific hazards investigated include winter weather, freeze-thaw cycles, hot and cold extremes, and heavy precipitation. Projections for each of these variables were calculated for the region, utilizing spatial mapping, and time series analysis at the climate division level. The results indicate that cold-season phenomena such as winter weather, freeze-thaw, and cold extremes, decrease in intensity and frequency, particularly with the higher emissions pathways. Nonetheless, specific model and downscaling method yields variability in magnitudes, with the most notable decreasing trends late in the 21st century. Hot days show a pronounced increase, particularly with greater emissions, producing annual mean 100oF day frequencies by late 21st century analogous to the 2011 heatwave over the central Southern Plains. Heavy precipitation, evidenced by return period estimates and counts-over-thresholds, also show notable increasing trends, particularly between the recent past through mid-21st Century. Conversely, mean precipitation does not show significant trends and is regionally variable. Precipitation hazards (e.g., winter weather, extremes) diverge between downscaling methods and their associated model samples much more substantially than temperature, suggesting that the choice of global model and downscaled data is particularly

  12. Quasi-periodic recurrence of great and giant earthquakes in South-Central Chile inferred from lacustrine turbidite records

    Science.gov (United States)

    Strasser, M.; Moernaut, J.; Van Daele, M. E.; De Batist, M. A. O.

    2017-12-01

    Coastal paleoseismic records in south-central Chile indicate that giant megathrust earthquakes -such as in AD1960 (Mw9.5)- occur on average every 300 yrs. Based on geodetic data, it was postulated that the area already has the potential for a Mw8 earthquake. However, to estimate the probability for such a great earthquake from a paleo-perspective, one needs to reconstruct the long-term recurrence pattern of megathrust earthquakes. Here, we present two long lacustrine records, comprising up to 35 earthquake-triggered turbidites over the last 4800 yrs. Calibration of turbidite extent with historical earthquake intensity reveals a different macroseismic intensity threshold (≥VII½ vs. ≥VI½) for the generation of turbidites at the coring sites. The strongest earthquakes (≥VII½) have longer recurrence intervals (292 ±93 yrs) than earthquakes with intensity of ≥VI½ (139 ±69 yrs). The coefficient of variation (CoV) of inter-event times indicate that the strongest earthquakes recur in a quasi-periodic way (CoV: 0.32) and follow a normal distribution. Including also "smaller" earthquakes (Intensity down to VI½) increases the CoV (0.5) and fits best with a Weibull distribution. Regional correlation of our multi-threshold shaking records with coastal records of tsunami and coseismic subsidence suggests that the intensity ≥VII½ events repeatedly ruptured the same part of the megathrust over a distance of at least 300 km and can be assigned to a Mw ≥ 8.6. We hypothesize that a zone of high plate locking -identified by GPS data and large slip in AD 1960- acts as a dominant regional asperity, on which elastic strain builds up over several centuries and mostly gets released in quasi-periodic great and giant earthquakes. For the next 110 yrs, we infer an enhanced probability for a Mw 7.7-8.5 earthquake whereas the probability for a Mw ≥ 8.6 (AD1960-like) earthquake remains low.

  13. Extensive Sediment Subduction along the South-Central Chile Margin and its Role in the Maule and Valdivia Megathrust Earthquakes

    Science.gov (United States)

    Bangs, N. L.; Arnulf, A. F.; Trehu, A. M.; Contreras-Reyes, E.

    2017-12-01

    In January and February of 2017 we acquired 5,000 km of multichannel seismic reflection data on the R/V Langseth along the south-central Chile margin between 30 °S and 44 °S. These data were acquired as a part of the Crustal Examination from Valdivia to Illapel to Characterize Huge Earthquakes (CEVICHE) project to examine subduction zone structure and the megathrust in the 2015 Illapel (Mw 8.3), 2010 Maule (Mw 8.8), and 1960 Valdivia (Mw 9.5) earthquake slip regions. We used a 1212-channel, 15.1-km-long streamer and a 36-airgun, 6,600 in3 seismic source. We acquired 17 margin-perpendicular dip lines, a strike line along the shelf and various strike segments along the midslope and trench. During the Valdivia event, a 1,000 km segment slipped and generated the largest earthquake ever recorded. This segment slips regularly every 300 years. In contrast, a 500-km-long region to the north slipped during the Maule earthquake where the margin typically ruptures at irregular intervals along 100 km long patches. The CEVICHE project was designed to image the structure that leads to regular, extremely large ruptures in the Valdivia region and irregular, variably sized earthquakes to the north. To date we have closely examined three dip lines between 37.5 °S and 39 °S across a region that slipped during both the Valdivia and Maule events. All three have been processed to image margin structure, and two have been processed using full waveform inversion (FWI), yielding detailed seismic impedance and velocity structure to 5-6 km subseafloor. The results show that nearly all of the 1.5 - 2.0 km of sediment in the trench is being subducted beneath the lower slope and virtually none is actively accreting at the deformation front. A similar thickness of low-velocity sediment can be traced above the top of the subducting crust to at least 5 km subseafloor. These sediments are subducted beneath a moderate to high-velocity (4.5 - 5.5 km/s) overriding plate structure that appears to

  14. Management of hunting waste as control measure for tuberculosis in wild ungulates in south-central Spain.

    Science.gov (United States)

    Cano-Terriza, D; Risalde, M A; Jiménez-Ruiz, S; Vicente, J; Isla, J; Paniagua, J; Moreno, I; Gortázar, C; Infantes-Lorenzo, J A; García-Bocanegra, I

    2018-03-13

    In recent decades, habitat change and the intensive management of wild ungulates for hunting have led to an increase in their populations in south-central Spain. This implies a higher generation of hunting waste, which can favour the transmission of infectious diseases, including tuberculosis (TB). The aim of this study was to assess the usefulness of the proper disposal of hunting waste as TB control measure in wild boar (Sus scrofa) and red deer (Cervus elaphus) during the 2008/2009 to 2016/2017 hunting seasons. Blood samples from 664 wild boar and 934 red deer were obtained in 14 game estates in two provinces in Andalusia (Area 1), where the disposal of hunting waste was implemented since the 2012/2013 hunting season. Besides, six game estates in the province of Ciudad Real, in Castilla-La Mancha (Area 2), an adjacent region where this management measure was not implemented during the studied period, were used as controls, sampling 277 wild boar and 427 red deer sera. The Mycobacterium tuberculosis complex (MTC), seroprevalence detected in wild boar from Area 1, was significantly higher before the disposal of big game hunting by-products (82.8%; 2008/2009-2012/2013) compared to the second period (61.8%; 2013/2014-2016/2017) (p < .001), after this control measure became established. By contrast, no significant differences between periods were found in wild boar (41.3% versus 44.8%; p = .33) and red deer (14.9% versus 11.6%; p = .19) from Area 2 as well as in red deer (10.8% versus 10.5%; p = .48) from Area 1. The proper disposal of hunting waste contributed to achieve a 25% reduction in MTC seroprevalence in wild boar. These results are of particular relevance regarding wild boar in the current context of re-emerging and emerging diseases such as TB and African Swine Fever in Europe. Further studies are needed to assess the effect of this measure on the health status of livestock and other wildlife species. © 2018 Blackwell Verlag GmbH.

  15. Possible impacts of climate change on freezing rain in south-central Canada using downscaled future climate scenarios

    Directory of Open Access Journals (Sweden)

    C. S. Cheng

    2007-01-01

    Full Text Available Freezing rain is a major atmospheric hazard in mid-latitude nations of the globe. Among all Canadian hydrometeorological hazards, freezing rain is associated with the highest damage costs per event. Using synoptic weather typing to identify the occurrence of freezing rain events, this study estimates changes in future freezing rain events under future climate scenarios for south-central Canada. Synoptic weather typing consists of principal components analysis, an average linkage clustering procedure (i.e., a hierarchical agglomerative cluster method, and discriminant function analysis (a nonhierarchical method. Meteorological data used in the analysis included hourly surface observations from 15 selected weather stations and six atmospheric levels of six-hourly National Centers for Environmental Prediction (NCEP upper-air reanalysis weather variables for the winter months (November–April of 1958/59–2000/01. A statistical downscaling method was used to downscale four general circulation model (GCM scenarios to the selected weather stations. Using downscaled scenarios, discriminant function analysis was used to project the occurrence of future weather types. The within-type frequency of future freezing rain events is assumed to be directly proportional to the change in frequency of future freezing rain-related weather types The results showed that with warming temperatures in a future climate, percentage increases in the occurrence of freezing rain events in the north of the study area are likely to be greater than those in the south. By the 2050s, freezing rain events for the three colder months (December–February could increase by about 85% (95% confidence interval – CI: ±13%, 60% (95% CI: ±9%, and 40% (95% CI: ±6% in northern Ontario, eastern Ontario (including Montreal, Quebec, and southern Ontario, respectively. The increase by the 2080s could be even greater: about 135% (95% CI: ±20%, 95% (95% CI: ±13%, and 45% (95% CI: ±9

  16. Frozen debris lobes, permafrost slope instability, and a potential infrastructure hazard in the south-central Brooks Range of Alaska

    Science.gov (United States)

    Daanen, R. P.; Darrow, M.; Grosse, G.; Jones, B. M.

    2012-12-01

    Here we report on investigations carried out at unusual debris mass-movement features (frozen debris lobes) on permafrost slopes in the south central portion of the Brooks Range of northern Alaska. The features under investigation are located in mountainous terrain near the southern border of continuous permafrost. The frozen debris lobes consist mainly of boulders, cobles, platy gravel sand and silt frozen debris derived from weathering mountain tops. The general dimensions of these lobes are either lobate or tongue shaped with widths up to 500 m and lengths up to 1200 m. In accumulation zones where slopes converge, the debris slowly moves as solifluction lobes, mud flows and potentially sliding toward the valley. These features were previously referred to as stable rock glaciers in the past, as evidenced by a dense cover of vegetation, and exhibiting no known downslope movement. Our investigations however, have shown that these features are indeed moving downslope as a result of creep, slumping, viscous flow, blockfall and leaching of fines in the summer; and in cold seasons by creep and sliding of frozen sediment slabs. Movement indicators observed in the field include toppling trees, slumps and scarps, detachment slides, striation marks on frozen sediment slabs, recently buried trees and other vegetation, mudflows, and large cracks in the lobe surface. Ground-based measurements on one frozen debris-lobe over three years (2008-2010) revealed average movement rates of approximately 1 cm day-1, which is substantially larger than rates measured in historic aerial photography from the 1950s to 1980s. Current observations , through lidar, ifsar, insar and ground based measurements using boreholes, geophysics and repeat photography of these features show an increase in movement activity that could be the result of rising summer temperatures in the region. Warming of ice rich permafrost slopes and frozen debris lobes in the Brooks Range pose a direct threat to the

  17. Utilization of institutional delivery service at Wukro and Butajera districts in the Northern and South Central Ethiopia.

    Science.gov (United States)

    Hagos, Seifu; Shaweno, Debebe; Assegid, Meselech; Mekonnen, Alemayehu; Afework, Mesganaw Fantahun; Ahmed, Saifuddin

    2014-05-28

    Ethiopia has one of the highest maternal mortality in the world. Institutional delivery is the key intervention in reducing maternal mortality and complications. However, the uptake of the service has remained low and the factors which contribute to this low uptake appear to vary widely. Our study aims to determine the magnitude and identify factors affecting delivery at health institution in two districts in Ethiopia. A community based cross sectional household survey was conducted from January to February 2012 in 12 randomly selected villages of Wukro and Butajera districts in the northern and south central parts of Ethiopia, respectively. Data were collected using a pretested questionnaire from 4949 women who delivered in the two years preceding the survey. One in four women delivered the index child at a health facility. Among women who delivered at health facility, 16.1% deliveries were in government hospitals and 7.8% were in health centers. The factors that significantly affected institutional delivery in this study were district in which the women lived (AOR: 2.21, 95% CI: 1.28, 3.82), women age at interview (AOR: 1.96, 95% CI: 1.05, 3.62), women's education (AOR: 3.53, 95% CI: 1.22, 10.20), wealth status (AOR: 16.82, 95% CI: 7.96, 35.54), women's occupation (AOR: 1.50, 95% CI: 1.01, 2.24), antenatal care (4+) use (AOR: 1.77, 95% CI: 1.42, 2.20), and number of pregnancies (AOR: 0.25, 95% CI: 0.18,0.35). We found that women who were autonomous in decision making about place of delivery were less likely to deliver in health facility (AOR: 0.38, 95% CI: 0.23,0.63). Institutional delivery is still low in the Ethiopia. The most important factors that determine use of institutional delivery appear to be women education and household economic status.Women's autonomy in decision making on place of delivery did not improve health facility delivery in our study population.Actions targeting the disadvantaged, improving quality of services and service availability in

  18. Fish habitat degradation in U.S. reservoirs

    Science.gov (United States)

    Miranda, Leandro E.; Spickard, M.; Dunn, T.; Webb, K.M.; Aycock, J.N.; Hunt, K.

    2010-01-01

    As the median age of the thousands of large reservoirs (> 200 ha) in the United States tops 50, many are showing various signs of fish habitat degradation. Our goal was to identify major factors degrading fish habitat in reservoirs across the country, and to explore regional degradation patterns. An online survey including 14 metrics was scored on a 0 (no degradation) to 5 (high degradation) point scale by 221 fisheries scientists (92% response rate) to describe degradation in 482 reservoirs randomly distributed throughout the continental United States. The highest scored sources of degradation were lack of aquatic macrophytes (41% of the reservoirs scored as 4–5), lack or loss of woody debris (35% scored 4–5), mistimed water level fluctuations (34% scored 4–5), and sedimentation (31% scored 4–5). Factor analysis identified five primary degradation factors that accounted for most of the variability in the 14 degradation metrics. The factors reflected siltation, structural habitat, eutrophication, water regime, and aquatic plants. Three degradation factors were driven principally by in-reservoir processes, whereas the other two were driven by inputs from the watershed. A comparison across U.S. regions indicated significant geographical differences in degradation relative to the factors emphasized by each region. Reservoirs sometimes have been dismissed as unnatural and disruptive, but they are a product of public policy, a critical feature of landscapes, and they cannot be overlooked if managers are to effectively conserve river systems. Protection and restoration of reservoir habitats may be enhanced with a broader perspective that includes watershed management, in addition to in reservoir activities.

  19. Seasonal assessment, treatment and removal of heavy metal concentrations in a tropical drinking water reservoir

    Directory of Open Access Journals (Sweden)

    Mustapha Moshood Keke

    2016-06-01

    Full Text Available Heavy metals are present in low concentrations in reservoirs, but seasonal anthropogenic activities usually elevate the concentrations to a level that could become a health hazard. The dry season concentrations of cadmium, copper, iron, lead, mercury, nickel and zinc were assessed from three sites for 12 weeks in Oyun reservoir, Offa, Nigeria. Triplicate surface water samples were collected and analysed using atomic absorption spectrophotometry. The trend in the level of concentrations in the three sites is site C > B > A, while the trend in the levels of the concentrations in the reservoir is Ni > Fe > Zn > Pb > Cd > Cu > Hg. Ni, Cd, Pb and Hg were found to be higher than the WHO guidelines for the metals in drinking water. The high concentration of these metals was from anthropogenic watershed run-off of industrial effluents, domestic sewages and agricultural materials into the reservoir coming from several human activities such as washing, bathing, fish smoking, especially in site C. The health effects of high concentration of these metals in the reservoir were highlighted. Methods for the treatment and removal of the heavy metals from the reservoir during water purification such as active carbon adsorption, coagulation-flocculation, oxidation-filtration, softening treatment and reverse osmosis process were highlighted. Other methods that could be used include phytoremediation, rhizofiltration, bisorption and bioremediation. Watershed best management practices (BMP remains the best solution to reduce the intrusion of the heavy metals from the watershed into the reservoir.

  20. Watershed storage and riverine particulate organic radiocarbon

    Science.gov (United States)

    Blair, N. E.; Leithold, E. L.

    2011-12-01

    -fossil organic C sources. The influence of watershed size emerges when bulk POC 14C measurements are deconvoluted into constituent signatures. Two key parameters are the concentration of fossil C and the apparent age of the non-fossil fraction. Hypothetically, fossil C derived from upland sources via the mass wasting of sedimentary rocks should decrease in abundance with time spent within surface bioactive reservoirs such as soils because of oxidative losses. Likewise, the 14C-age of non-fossil C (contemporary plus aged soil C) should increase with time spent in the watershed. Though riverine radiocarbon data sets are small, they are consistent with both predictions. The bulk radiocarbon signatures of riverine POC thus appear to result from a balance of processes that turn over sediment-associated organic material.

  1. Watershed Central: A New Gateway to Watershed Information

    Science.gov (United States)

    Many communities across the country struggle to find the right approaches, tools and data to in their watershed plans. EPA recently posted a new Web site called "Watershed Central, a “onestop" tool, to help watershed organizations and others find key resources to protect their ...

  2. Recent (2008-10) concentrations and isotopic compositions of nitrate and concentrations of wastewater compounds in the Barton Springs zone, south-central Texas, and their potential relation to urban development in the contributing zone

    Science.gov (United States)

    Mahler, Barbara J.; Musgrove, MaryLynn; Herrington, Chris; Sample, Thomas L.

    2011-01-01

    During 2008–10, the U.S. Geological Survey, in cooperation with the City of Austin, the City of Dripping Springs, the Barton Springs/Edwards Aquifer Conservation District, the Lower Colorado River Authority, Hays County, and Travis County, collected and analyzed water samples from five streams (Barton, Williamson, Slaughter, Bear, and Onion Creeks), two groundwater wells (Marbridge well [YD–58–50–704] and Buda well [LR–58–58–403]), and the main orifice of Barton Springs in Austin, Texas, with the objective of characterizing concentrations and isotopic compositions of nitrate and concentrations of wastewater compounds in the Barton Springs zone. The Barton Springs zone is in south-central Texas, an area undergoing rapid growth in population and in land area affected by development, with associated increases in wastewater generation. Over a period of 17 months, during which the hydrologic conditions transitioned from dry to wet, samples were collected routinely from the streams, wells, and spring and, in response to storms, from the streams and spring; some or all samples were analyzed for nitrate, nitrogen and oxygen isotopes of nitrate, and waste­water compounds. The median nitrate concentrations in routine samples from all sites were higher in samples collected during the wet period than in samples collected during the dry period, with the greatest difference for stream samples (0.05 milligram per liter during the dry period to 0.96 milligram per liter for the wet period). Nitrate concentrations in recent (2008–10) samples were elevated relative to concentrations in historical (1990–2008) samples from streams and from Barton Springs under medium- and high-flow conditions. Recent nitrate concentrations were higher than historical concentrations at the Marbridge well but the reverse was true at the Buda well. The elevated concentrations likely are related to the cessation of dry conditions coupled with increased nitrogen loading in the

  3. Landscape evolution in south-central Minnesota and the role of geomorphic history on modern erosional processes

    Science.gov (United States)

    Gran, K.B.; Belmont, P.; Day, S.S.; Finnegan, N.; Jennings, C.; Lauer, J.W.; Wilcock, P.R.

    2011-01-01

    The Minnesota River Valley was carved during catastrophic drainage of glacial Lake Agassiz at the end of the late Pleistocene. The ensuing base-level drop on tributaries created knickpoints that excavated deep valleys as they migrated upstream. A sediment budget compiled in one of these tributaries, the Le Sueur River, shows that these deep valleys are now the primary source of sediment to the Minnesota River. To compare modern sediment loads with pre-European settlement erosion rates, we analyzed incision history using fluvial terrace ages to constrain a valley incision model. Results indicate that even thoughthe dominant sediment sources are derived from natural sources (bluffs, ravines, and streambanks), erosion rates have increased substantially, due in part to pervasive changes in watershed hydrology.

  4. River profile response to normal fault growth and linkage: an example from the Hellenic forearc of south-central Crete, Greece

    Science.gov (United States)

    Gallen, Sean F.; Wegmann, Karl W.

    2017-02-01

    Topography is a reflection of the tectonic and geodynamic processes that act to uplift the Earth's surface and the erosional processes that work to return it to base level. Numerous studies have shown that topography is a sensitive recorder of tectonic signals. A quasi-physical understanding of the relationship between river incision and rock uplift has made the analysis of fluvial topography a popular technique for deciphering relative, and some argue absolute, histories of rock uplift. Here we present results from a study of the fluvial topography from south-central Crete, demonstrating that river longitudinal profiles indeed record the relative history of uplift, but several other processes make it difficult to recover quantitative uplift histories. Prior research demonstrates that the south-central coastline of Crete is bound by a large ( ˜ 100 km long) E-W striking composite normal fault system. Marine terraces reveal that it is uplifting between 0.1 and 1.0 mm yr-1. These studies suggest that two normal fault systems, the offshore Ptolemy and onshore South-Central Crete faults, linked together in the recent geologic past (ca. 0.4-1 My BP). Fault mechanics predict that when adjacent faults link into a single fault the uplift rate in footwalls of the linkage zone will increase rapidly. We use this natural experiment to assess the response of river profiles to a temporal jump in uplift rate and to assess the applicability of the stream power incision model to this setting. Using river profile analysis we show that rivers in south-central Crete record the relative uplift history of fault growth and linkage as theory predicts that they should. Calibration of the commonly used stream power incision model shows that the slope exponent, n, is ˜ 0.5, contrary to most studies that find n ≥ 1. Analysis of fluvial knickpoints shows that migration distances are not proportional to upstream contributing drainage area, as predicted by the stream power incision model

  5. Reservoir Sedimentation and Upstream Sediment Sources: Perspectives and Future Research Needs on Streambank and Gully Erosion

    Science.gov (United States)

    Fox, G. A.; Sheshukov, A.; Cruse, R.; Kolar, R. L.; Guertault, L.; Gesch, K. R.; Dutnell, R. C.

    2016-05-01

    The future reliance on water supply and flood control reservoirs across the globe will continue to expand, especially under a variable climate. As the inventory of new potential dam sites is shrinking, construction of additional reservoirs is less likely compared to simultaneous flow and sediment management in existing reservoirs. One aspect of this sediment management is related to the control of upstream sediment sources. However, key research questions remain regarding upstream sediment loading rates. Highlighted in this article are research needs relative to measuring and predicting sediment transport rates and loading due to streambank and gully erosion within a watershed. For example, additional instream sediment transport and reservoir sedimentation rate measurements are needed across a range of watershed conditions, reservoir sizes, and geographical locations. More research is needed to understand the intricate linkage between upland practices and instream response. A need still exists to clarify the benefit of restoration or stabilization of a small reach within a channel system or maturing gully on total watershed sediment load. We need to better understand the intricate interactions between hydrological and erosion processes to improve prediction, location, and timing of streambank erosion and failure and gully formation. Also, improved process-based measurement and prediction techniques are needed that balance data requirements regarding cohesive soil erodibility and stability as compared to simpler topographic indices for gullies or stream classification systems. Such techniques will allow the research community to address the benefit of various conservation and/or stabilization practices at targeted locations within watersheds.

  6. Remarks on Echinodermata from the South Central Mediterranean Sea based upon collections made during the MARCOS cruise (10 to 20th April, 2007

    Directory of Open Access Journals (Sweden)

    C. MIFSUD

    2009-12-01

    Full Text Available The MARCOS cruise, which took place in the South Central Mediterranean Sea on board the RV ‘Urania’, resulted in the collection of 27 species of Echinodermata from shallow to bathyal depths, many from around Malta (the Fisheries Management Zone. The fauna is represented by common to rare taxa already reported from the Mediterranean with the exception of the amphi-Atlantic ophiuroid Ophiotreta valenciennesi rufescens (Koehler, 1896, recorded from the Mediterranean Basin for the first time. Odontaster mediterraneus (von Marenzeller, 1893 and Luidia sarsi Lutken, 1858 are also first records for the Maltese Islands.

  7. Ground-water quality in Quaternary deposits of the central High Plains aquifer, south-central Kansas, 1999

    Science.gov (United States)

    Pope, Larry M.; Bruce, Breton W.; Hansen, Cristi V.

    2001-01-01

    Water samples from 20 randomly selected domestic water-supply wells completed in the Quaternary deposits of south-central Kansas were collected as part of the High Plains Regional Ground-Water Study conducted by the U.S. Geological Survey's National Water-Quality Assessment Program. The samples were analyzed for about 170 water-quality constituents that included physical properties, dissolved solids and major ions, nutrients and dissolved organic carbon, trace elements, pesticides, volatile organic compounds, and radon. The purpose of this study was to provide a broad overview of ground-water quality in a major geologic subunit of the High Plains aquifer. Water from five wells (25 percent) exceeded the 500-milligrams-per-liter of dissolved solids Secondary Maximum Contaminant Level for drinking water. The Secondary Maximum Contaminant Levels of 250 milligrams per liter for chloride and sulfate were exceeded in water from one well each. The source of these dissolved solids was probably natural processes. Concentrations of most nutrients in water from the sampled wells were small, with the exception of nitrate. Water from 15 percent of the sampled wells had concentrations of nitrate greater than the 10-milligram-per-liter Maximum Contaminant Level for drinking water. Water from 80 percent of the sampled wells showed nitrate enrichment (concentrations greater than 2.0 milligrams per liter), which is more than what might be expected for natural background concentrations. This enrichment may be the result of synthetic fertilizer applications, the addition of soil amendment (manure) on cropland, or livestock production. Most trace elements in water from the sampled wells were detected only in small concentrations, and few exceeded respective water-quality standards. Only arsenic was detected in one well sample at a concentration (240 micrograms per liter) that exceeded its proposed Maximum Contaminant Level (5.0 micrograms per liter). Additionally, one concentration of

  8. Assessing and mapping drought hazard in Africa and South-Central America with a Meteorological Drought Severity Index

    Science.gov (United States)

    Carrao, Hugo; Barbosa, Paulo; Vogt, Jürgen

    2015-04-01

    the intra-annual variability of precipitation in estimating the severity of events that can impact on seasonal activities. The MDSI is standardized in space and time, and considers the relative monthly precipitation deficits and the seasonal influence of precipitation regimes in the meteorological drought severity computation. In this study, the calculation of the MDSI is performed with monthly precipitation totals from the Full Data Reanalysis Monthly Product Version 6.0 of the Global Precipitation Climatology Centre (GPCC). This dataset provides a global analysis at 0.5 dd latitude/longitude grid spacing of monthly precipitation over land from operational in situ rain gauges collected between January 1901 and December 2010. Using the MDSI, we estimated the severity of drought events that occurred in the past 100 years in Africa and South-Central America, and produced drought hazard maps based on the probability of exceedance the median historical severity. Overall, results indicate that drought hazard is high for semiarid areas, such as Northeastern and Southern South America, as well as Eastern and Southwestern Africa. Since available water resources in semiarid areas are already insufficient to permanently meet the demands of human activities, the outcomes highlight the aggravated risk for food security and confirm the need for the implementation of disaster mitigation measures in those regions.

  9. Evaulation of remote sensing, geological and geophysical data for south-central New York and northern Pennsylvania

    Science.gov (United States)

    Podwysocki, M.H.; Pohn, H.A.; Phillips, J.D.; Krohn, M.D.; Purdy, T.L.; Merin, I.S.

    1982-01-01

    A study was made of the relationship between lineaments observed on Landsat satellite images and the geologic framework of a portion of the Allegheny Plateau of south-central New York and northern Pennsylvania. The area is underlain by a relatively thick sequence of salt and other evaporites in the Silurian Salina Group and is a potential site for deep-storage of solid nuclear waste. A combination of remote sensing techniques, detailed geologic mapping and geophysical investigations were applied to the problem. Because of the premature termination of the Department of Energy contract, only a portion of the total work was completed. The completed portion of the project included 1) digital contrast enhancement of several Landsat multispectral scanner (MSS) images, 2) analysis of lineament patterns from a Landsat MSS-7 mosaic, 3) field mapping of bedrock joint patterns, 4) compilation and analysis of surface and subsurface structure and isopach maps, 5) collection and digital analysis of aeromagnetic data for southern New York, 6) compilation and analysis of aeromagnetic and gravity data for much of New York and Pennsylvania, and 7) analysis of seismic reflection survey lines for selected portions of New York and Pennsylvania. We identified eight major lineaments or lineament zones and studied them in detail. They typically represent linear alignments of the most conspicuous or prominent physiographic features observable on Landsat images. The Cortland-Ithaca, Watkins Glen-Tanghannock, Seneca Lake-Elmira, Painted Post-Blossburg and Endicott-Syracuse conspicuous lineaments include the Corning-Bath, Van Etten-Towanda, Van Etten-Candor and Van Etten-Odessa lineaments. In addition, a major fault system--the West Danby fault zone--was further defined by geologic and geophysical investigations during our study; the fault zone was not recognizable on satellite images. The lineaments and lineament zones were categorized by their azimuthal trends. Those with a northerly

  10. An assessment of flow data from Klamath River sites between Link River Dam and Keno Dam, south-central Oregon

    Science.gov (United States)

    Risley, John C.; Hess, Glen W.; Fisher, Bruce J.

    2006-01-01

    Records of diversion and return flows for water years 1961?2004 along a reach of the Klamath River between Link River and Keno Dams in south-central Oregon were evaluated to determine the cause of a water-balance inconsistency in the hydrologic data. The data indicated that the reach was losing flow in the 1960s and 1970s and gaining flow in the 1980s and 1990s. The absolute mean annual net water-balance difference in flows between the first and second half of the 44-year period (1961-2004) was approximately 103,000 acre-feet per year (acre-ft/yr). The quality of the diversion and return-flow records used in the water balance was evaluated using U.S. Geological Survey (USGS) criteria for accuracy. With the exception of the USGS Klamath River at Keno record, which was rated as 'good' or 'excellent,' the eight other flow records, all from non-USGS flow-measurement sites, were rated as 'poor' by USGS standards due to insufficient data-collection documentation and a lack of direct discharge measurements to verify the rating curves. The record for the Link River site, the most upstream in the study area, included both river and westside power canal flows. Because of rating curve biases, the river flows might have been overestimated by 25,000 acre-ft/yr on average from water years 1961 to 1982 and underestimated by 7,000 acre-ft/yr on average from water years 1983 to 2004. For water years 1984-2004, westside power canal flows might have been underestimated by 11,000 acre-ft/yr. Some diversion and return flows (for mostly agricultural, industrial, and urban use) along the Klamath River study reach, not measured continuously and not included in the water-balance equation, also were evaluated. However, the sum of these diversion and return flows was insufficient to explain the water-balance inconsistency. The possibility that ground-water levels in lands adjacent to the river rose during water years 1961-2004 and caused an increase in ground-water discharge to the river

  11. Changes in Channel Geometry through the Holocene in the Le Sueur River, South-Central Minnesota, USA

    Science.gov (United States)

    Targos, Courtney Ann

    Paleochannels preserved on terraces via meander cutoffs during an incisional period record the channel geometry and thus discharge at distinct points in time throughout a river's history. We measured paleochannel geometry on terraces throughout the Le Sueur River in south-central Minnesota, to track how channel geometry has changed over the last 13,400 years. A rapid drop in base level 13,400 yr B.P. triggered knickpoint migration and valley incision that is ongoing today. Since the 1800's, the area has developed rapidly with an increase in agriculture and associated drainage, directly impacting river discharge by increasing water input to the river. Five paleochannels were identified on terraces along the Le Sueur River from 1m-resolution lidar data. Ground Penetrating Radar (GPR) was used to obtain a subsurface image across paleomeanders to estimate the geometry of paleochannels. Paleochannel geometry and estimated discharge were then compared to modern conditions to assess how much change has occurred. Three lines were run across each paleochannel perpendicular to the historic water flow. Each of the 15 lines were processed using the EKKO Project 2 software supplied by Sensors and Software to sharpen the images, making it easier to identify the paleochannel geometry. Paleodischarge was determined using the Law of the Wall and Manning's Equation, using modern slope and roughness conditions. OSL samples were collected from overbank deposits on terraces to determine the time of channel abandonment, and supplemented with terrace ages obtained from a numerical model of valley incision. Paleodischarge coupled with depositional ages provide a history of flow conditions on the Le Sueur River. Results show an increase in channel widths from the time paleochannels were occupied to modern channel dimensions from an average of 20 meters to 35 meters. The change was not constant through time, as all paleochannels analyzed on terraces had similar-sized channels. The best way

  12. Fens, seasonal wetlands, and the unconfined pumice aquifer east of the Cascade Range, south-central Oregon

    Science.gov (United States)

    Cummings, M. L.; Large, A.; Mowbray, A.; Weatherford, J.; Webb, B.

    2013-12-01

    Fens and seasonal wetlands in the headwaters of the Klamath and Deschutes river basins in south-central Oregon are present in an area blanketed by 2 to 3 m of pumice during the Holocene eruption of Mount Mazama. The lower pumice unit, moderately sorted coarse pumice lapilli to blocks (0.3 to 0.7 cm), phenocrysts, and lithics is 1.5 to 2 m thick; the upper pumice unit, poorly sorted lapilli to blocks (0.2 to 6 cm), minor phenocrysts, and lithics is 1 m thick. Pumice is a perched, unconfined aquifer over low permeability bedrock or pre-eruption fine-grained sediment. Early landscape response included partial erosion of pumice from pre-eruption valleys followed by partial filling by alluvium: phenocryst- and lithic-rich sand grading upward to glassy silt with rounded pumice pebbles. Groundwater-fed wetlands, fens, associated with the unconfined pumice aquifer occur as areas of diffuse groundwater discharge through gently sloping, convex surfaces underlain by up to 1.4 m of peat. Locally, focused discharge through the confining peat layer feeds low discharge streams. Carnivorous plants (sundews and pitcher plants) may be present. The sharp contact between peat and underlying pumice is an erosion surface that cuts progressively deeper into the upper and lower pumice units downslope. At the base of the slope peat with fen discharge feeding surface flow, alluvium with no surface flow, or a subtle berm separating the slope underlain by peat from the valley bottom underlain by alluvium may be present. Distinct vegetation changes take place at this transition. The erosion surface that underlies the peat layer in the fen is at the surface on the opposing valley wall and progressively rises up through the lower and upper pumice units: iron staining and cementation of pumice is locally prominent. Up to 1.5 m difference in water table occurs between the fen and opposing valley wall. Water table in piezometers screened in peat is at the surface. Locally, water table screened in

  13. Suspended-sediment inflows to Watts Bar Reservoir. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, L.K.

    1993-09-01

    Suspended-sediment inflows to Watts Bar Reservoir are important data that are required in numerical modeling of transport and deposition of sediment in the reservoir. Acceptable numerical modeling requires sediment inflow rates and locations in order to be able to compute the location and quantity of sediment deposited within the reservoir. Therefore, the representativeness of modeling results is highly dependent on the characteristics of sediment input to the model. The following recommendations, that account for suspended-sediment inflows to be used in the numerical modeling of sediment transport and deposition in Watts Bar Reservoir, were developed through an evaluation of available watershed and sediment deposition data. (1) Use the suspended-sediment rating regression equations of Gaydos et al., for Emory River at Oakdale, TN, and for Poplar Creek near Oak Ridge, TN, to represent the suspended-sediment inflows into Watts Bar Reservoir from its tributaries; (2) Use a suspended-sediment rating regression equation that was derived from suspended-sediment and streamflow data of the Little Tennessee River at McGhee, TN, to represent sediment inflow from the Little Tennessee River for simulation of any historical year before the completion of Tellico Dam; (3) Check the appropriateness of any assumption for suspended-sediment inflows from upstream reservoirs by using its long-term relationship to local suspended-sediment inflows and to the suspended-sediment outflow through Watts Bar Dam; and (4) Focus refinements to suspended-sediment inflow rates on the Clinch arm of Watts Bar Reservoir.

  14. Factors controlling the fluvial export of large woody debris, and its contribution to organic carbon budgets at watershed scales

    Science.gov (United States)

    Seo, Jung Il; Nakamura, Futoshi; Nakano, Daisuke; Ichiyanagi, Hidetaka; Chun, Kun Woo

    2008-04-01

    The fluvial export of large woody debris (LWD) was monitored in 131 reservoirs throughout Japan. Published data on the fluvial export of dissolved and particulate organic carbon were used to estimate the contributions of LWD in carbon budgets. Of all variables tested, watershed area was most important in explaining LWD carbon (LWDC) export, followed by annual precipitation. LWDC export per unit area was relatively high in small watersheds, highest in intermediate-sized watersheds, and decreased in large watersheds. In small watersheds, a large proportion of LWD retained on narrow valley floors may fragment or decay and eventually be exported in forms other than LWD. In intermediate-sized watersheds, LWD supplied from upstream and recruited by bank erosion is consistently transported downstream. In large watersheds, LWD recruitment is limited and LWD transported from upstream is stored on large floodplains. These differences in LWD recruitment, retention and transport in watersheds of different sizes lead to the proportion of LWDC in organic carbon exports to be maximum in intermediate-sized watersheds and decline rapidly in large watersheds.

  15. Hydrological modeling of a watershed affected by acid mine drainage (Odiel River, SW Spain). Assessment of the pollutant contributing areas

    Science.gov (United States)

    Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.

    2016-09-01

    The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.

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

    International Nuclear Information System (INIS)

    McHenry, J.R.; Ritchie, J.C.

    1977-01-01

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

  17. Fundamentals of watershed hydrology

    Science.gov (United States)

    Pamela J. Edwards; Karl W.J. Williard; Jon E. Schoonover

    2015-01-01

    This is a primer about hydrology, the science of water. Watersheds are the basic land unit for water resource management and their delineation, importance, and variation are explained and illustrated. The hydrologic cycle and its components (precipitation, evaporation, transpiration, soil water, groundwater, and streamflow) which collectively provide a foundation for...

  18. Watershed hydrology. Chapter 7.

    Science.gov (United States)

    Elons S. Verry; Kenneth N. Brooks; Dale S. Nichols; Dawn R. Ferris; Stephen D. Sebestyen

    2011-01-01

    Watershed hydrology is determined by the local climate, land use, and pathways of water flow. At the Marcell Experimental Forest (MEF), streamflow is dominated by spring runoff events driven by snowmelt and spring rains common to the strongly continental climate of northern Minnesota. Snowmelt and rainfall in early spring saturate both mineral and organic soils and...

  19. Watersheds in disordered media

    Directory of Open Access Journals (Sweden)

    José S. Andrade Jr.

    2015-02-01

    Full Text Available What is the best way to divide a rugged landscape? Since ancient times, watershedsseparating adjacent water systems that flow, for example, toward different seas, have beenused to delimit boundaries. Interestingly, serious and even tense border disputes betweencountries have relied on the subtle geometrical properties of these tortuous lines. For instance,slight and even anthropogenic modifications of landscapes can produce large changes in awatershed, and the effects can be highly nonlocal. Although the watershed concept arisesnaturally in geomorphology, where it plays a fundamental role in water management, landslide,and flood prevention, it also has important applications in seemingly unrelated fields suchas image processing and medicine. Despite the far-reaching consequences of the scalingproperties on watershed-related hydrological and political issues, it was only recently that a moreprofound and revealing connection has been disclosed between the concept of watershed andstatistical physics of disordered systems. This review initially surveys the origin and definition of awatershed line in a geomorphological framework to subsequently introduce its basic geometricaland physical properties. Results on statistical properties of watersheds obtained from artificialmodel landscapes generated with long-range correlations are presented and shown to be ingood qualitative and quantitative agreement with real landscapes.

  20. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT ...

    Science.gov (United States)

    The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS2) hydrologic models. The application of these two models allows AGWA to conduct hydrologic modeling and watershed assessments at multiple temporal and spatial scales. AGWA’s current outputs are runoff (volumes and peaks) and sediment yield, plus nitrogen and phosphorus with the SWAT model. AGWA uses commonly available GIS data layers to fully parameterize, execute, and visualize results from both models. Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM) based on the individual model requirements. The watershed model elements are then intersected with soils and land cover data layers to derive the requisite model input parameters. The chosen model is then executed, and the results are imported back into AGWA for visualization. This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. AGWA also has tools to apply an array of best management practices. There are currently two versions of AGWA available; AGWA 1.5 for

  1. Allegheny County Watershed Boundaries

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset demarcates the 52 isolated sub-Watersheds of Allegheny County that drain to single point on the main stem rivers. Created by 3 Rivers 2nd Nature based...

  2. Understanding recurrent land use processes and long-term transitions in the dynamic south-central United States, c. 1800 to 2006

    Science.gov (United States)

    Drummond, Mark A.; Griffith, Glenn E.; Auch, Roger F.; Stier, Michael P.; Taylor, Janis L.; Hester, David J.; Riegle, Jodi L.; McBeth, Jamie L.

    2017-01-01

    Forests have historically been under significant land use pressures that cause periods of degradation, clearance, and recovery. To understand these changes, studies are needed that place trends in a historical landscape context and also examine recent dynamics. Here, we use historical investigation (c. 1800) and an examination of land use and land cover change between 1973 and 2006 to establish a baseline trajectory of the forested system of the south-central United States (US) plains. The study culminates in a highly detailed accounting of the processes and causes of land change between 2001 and 2006. In the study region, the forest transitioned from early low-intensity use, to clearance for farming and timber, to widespread recovery from degradation beginning in the 1930s. By 1970, the region was transitioning from recovered woodlands to an intensive regime of recurrent timber harvest and replanting. The recurring cycle inherent in intensive silviculture has been the main cause of land change for the past several decades, accounting for more than 95% of the total extent of change between 2001 and 2006. The transition to forest recovery in the south-central US was an important historical occurrence. However, the dynamic post-transition landscape needs to be better understood.

  3. Amphibian, reptilian, and avian remains from the Fox Hills Formation (Maastrichtian): Shoreline and estuarine deposits of the Pierre Sea in south-central North Dakota

    Science.gov (United States)

    Hoganson, J.W.; Erickson, J.M.; Holland, F.D.

    2007-01-01

    Although vertebrate fossils, except for fish, are not common in the Maastrichtian Fox Hills Formation, amphibian, reptilian, and avian remains have been recovered at several localities in south-central North Dakota from shoreline facies of the retreating Pierre-Fox Hills seaway. This mixed fauna of aquatic, terrestrial, and marine taxa provides insight into the composition of coastal communities and habitats at the interface between the Hell Creek delta and the Western Interior Seaway. The delta-platform aquatic paleocommunity is represented by the efficient swimming salamanders Opistho- trition kayi and Lisserpeton bairdi, the carnivorous soft-shelled turtle "Aspideretes" sensu lato, the underwater piscivorous predator Champsosaurus laramiensis, and the large, predatory crocodile IBorealosuchus. Terrestrial areas were inhabited by the tortoise-like Basilemys and the predatory dinosaurs Tyrannosaurus and cf. Saurornit- holestes. Birds occupied niches in the warm-temperate to subtropical, forested delta platform and shoreline areas. These nonmarine taxa in the Fox Hills Formation indicate that the geographic range of these animals extended to shoreline areas of the Western Interior Seaway. The toxochelyid turtle Lophochelys and the ambush predators Mosasaurus dekayi and IPlioplatecarpus resided in the shallow marine and estuarine habitats. These taxa and marine fish taxa reported earlier indicate that normal marine conditions in south- central North Dakota persisted into the latest Late Cretaceous in comparison with coeval Hell Creek Formation sites more distal from the Western Interior Seaway. ?? 2007 The Geological Society of America. All rights reserved.

  4. Triatominae survey (Hemiptera: Reduviidae: Triatominae) in the south-central region of the state of Bahia, Brazil between 2008 and 2013.

    Science.gov (United States)

    Mendonça, Vagner José; de Oliveira, Jader; Rimoldi, Aline; Filho, Júlio C R Ferreira; de Araújo, Renato Freitas; da Rosa, João Aristeu

    2015-05-01

    Triatomine surveillance in rural areas, artificial ecotypes, and natural ecotopes of the cities of Caturama, Ibipitanga, Macaúbas, and Seabra in the south-central region of the Brazilian state of Bahia was carried out between 2008 and 2013. Natural infection by Trypanosoma cruzi was evaluated in the specimens collected to monitor vectors of Chagas disease. A total of 1,357 specimens were collected, and four species were identified: Triatoma sordida (83%), Triatoma lenti (16.4%), Triatoma pseudomaculata (0.5%), and Panstrongylus geniculatus (0.1%). Triatoma sordida was found in four cities, only 0.7% in intradomiciliary environments. Triatoma lenti was found only in Macaúbas; 8.5% were found in intradomiciliary environments, 88.3% in peridomiciliary environments, and 3.1% in sylvatic environments. Natural infection by T. cruzi was 0.5% for T. sordida and 3.1% T. lenti. All of these cases were found in peridomiciliary environments of Macaúbas. As the results show, triatomines were found in intradomiciliary environments in three cities that were surveyed in the south-central region of the state of Bahia. Thus, an epidemiologic survey should be performed to avoid the risk of transmission to the population. © The American Society of Tropical Medicine and Hygiene.

  5. Watershed controls on the export of large wood from stream corridors

    Science.gov (United States)

    Fremier, Alexander K.; Seo, Jung Il; Nakamura, Futoshi

    2010-04-01

    Large wood maintains in-channel and floodplain habitats by influencing the biophysical character of the river corridor. Large wood dynamics in a river corridor are a product of watershed wide processes and also of local recruitment, transport, and storage. This complexity of scales added to the logistical constraints in taking measurements limits our understanding of large wood dynamics through the watershed. To begin to unravel this issue, we compiled a data set of the volume of large wood deposited annually into 131 reservoirs across Japan and compared large wood export to flow discharge and watershed characteristics (watershed size, latitude, channel slope, percent forest, and forest type). We found that large wood was predominately transported during peak flow events. Large wood export increased logarithmically with watershed area. The decreasing export rate of large wood per watershed area is interpreted as a combination of annual export variability in upper watersheds, a non-significant increase in large wood recruitment along the longitudinal gradient (potentially human influenced), the increase in long-term storage on adjacent large floodplains, and significant decay/fragmentation downstream. Watersheds < 10-20 km2 had a highly variable large wood export pattern, conforming generally to previously published work that suggest transport limitation in smaller watersheds. The data suggest the existence of an export threshold (∼ 75 km2) where large wood export is no longer related to watershed size. Export across all watershed sizes was controlled by watershed characteristics (slope, percent forested, etc.) and peak discharge events. The connection with upstream watersheds and laterally with the floodplain increases the net flux of large wood through downstream transport and retransport of buried logs. Identifying rates of large wood transport from watershed connectivity as a potential key input process will improve our basic understanding of geomorphic and

  6. Hydrological controls on cascade reservoirs regulating phosphorus retention and downriver fluxes.

    Science.gov (United States)

    Lu, Ting; Chen, Nengwang; Duan, Shuiwang; Chen, Zhuhong; Huang, Bangqin

    2016-12-01

    Many coastal rivers have a system of cascade reservoirs, but the role of these reservoirs in regulating nutrient transport from watershed to coast is still unknown. In this study, phosphorus (P) in surface water and top sediment was investigated along the North Jiulong River (southeast China) under three hydrological conditions (high flow, medium flow and low flow) in 2012-2013, and P dynamics in a cascade reservoir (Xipi Reservoir) were studied on a monthly scale. Results showed that the concentrations of dissolved reactive phosphorus (DRP) consistently decreased longitudinally in the upper river with the lowest values observed in the section of cascade reservoirs, likely due to tributary inputs and in situ uptakes. The decrease was most rapid during base flow when DRP was highest in the free-flowing river section and lowest in cascade reservoirs. Results from monthly monitoring on the Xipi Reservoir showed general downriver decreases in DRP, total particulate phosphorus (TPP) and total phosphorus (TP) in the riverine zone and transition zone. Mass balance results on an annual basis suggest that the Xipi Reservoir (lacustrine zone) was an overall sink for TPP (6 % retention) but somewhat a source of DRP (-0.3 %) with TP retention (1 %). Even scaled up to the whole cascade reservoir system, P retention was low compared with worldwide reservoirs, which we ascribe to the high P loading and short hydraulic residence time. Nevertheless, major processes controlling P retention in coastal rivers with cascade reservoirs varied from sedimentation in the dry-cold season to biotic transformation in the wet-warm season, thereby affecting loading and composition of P from watershed to the coast. This study highlights the hydrological controls on the role of cascade reservoirs in regulating P retention and downriver fluxes in different seasons.

  7. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...

  8. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Calls have been made to the government through various media to assist its populace in combating this nagging problem. It was concluded that sediment maximum accumulation is experienced in reservoir during the periods of maximum flow. Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1.

  9. Dynamic reservoir well interaction

    NARCIS (Netherlands)

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.

    2004-01-01

    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady

  10. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  11. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  12. Larger earthquakes recur more periodically: New insights in the megathrust earthquake cycle from lacustrine turbidite records in south-central Chile

    Science.gov (United States)

    Moernaut, J.; Van Daele, M.; Fontijn, K.; Heirman, K.; Kempf, P.; Pino, M.; Valdebenito, G.; Urrutia, R.; Strasser, M.; De Batist, M.

    2018-01-01

    Historical and paleoseismic records in south-central Chile indicate that giant earthquakes on the subduction megathrust - such as in AD1960 (Mw 9.5) - reoccur on average every ∼300 yr. Based on geodetic calculations of the interseismic moment accumulation since AD1960, it was postulated that the area already has the potential for a Mw 8 earthquake. However, to estimate the probability of such a great earthquake to take place in the short term, one needs to frame this hypothesis within the long-term recurrence pattern of megathrust earthquakes in south-central Chile. Here we present two long lacustrine records, comprising up to 35 earthquake-triggered turbidites over the last 4800 yr. Calibration of turbidite extent with historical earthquake intensity reveals a different macroseismic intensity threshold (≥VII1/2 vs. ≥VI1/2) for the generation of turbidites at the coring sites. The strongest earthquakes (≥VII1/2) have longer recurrence intervals (292 ±93 yrs) than earthquakes with intensity of ≥VI1/2 (139 ± 69yr). Moreover, distribution fitting and the coefficient of variation (CoV) of inter-event times indicate that the stronger earthquakes recur in a more periodic way (CoV: 0.32 vs. 0.5). Regional correlation of our multi-threshold shaking records with coastal paleoseismic data of complementary nature (tsunami, coseismic subsidence) suggests that the intensity ≥VII1/2 events repeatedly ruptured the same part of the megathrust over a distance of at least ∼300 km and can be assigned to Mw ≥ 8.6. We hypothesize that a zone of high plate locking - identified by geodetic studies and large slip in AD 1960 - acts as a dominant regional asperity, on which elastic strain builds up over several centuries and mostly gets released in quasi-periodic great and giant earthquakes. Our paleo-records indicate that Poissonian recurrence models are inadequate to describe large megathrust earthquake recurrence in south-central Chile. Moreover, they show an enhanced

  13. Effects of mountain tea plantations on nutrient cycling at upstream watersheds

    Science.gov (United States)

    Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

    2015-11-01

    The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of

  14. Adaptive Management Fitness of Watersheds

    Directory of Open Access Journals (Sweden)

    Ignacio Porzecanski

    2012-09-01

    Full Text Available Adaptive management (AM promises to improve our ability to cope with the inherent uncertainties of managing complex dynamic systems such as watersheds. However, despite the increasing adherence and attempts at implementation, the AM approach is rarely successful in practice. A one-size-fits-all AM strategy fails because some watersheds are better positioned at the outset to succeed at AM than others. We introduce a diagnostic tool called the Index of Management Condition (IMC and apply it to twelve diverse watersheds in order to determine their AM "fitness"; that is, the degree to which favorable adaptive management conditions are in place in a watershed.

  15. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  16. Quantification of Interbasin Transfers into the Addicks Reservoir during Hurricane Harvey

    Science.gov (United States)

    Sebastian, A.; Juan, A.; Gori, A.; Maulsby, F.; Bedient, P. B.

    2017-12-01

    Between August 25 and 30, Hurricane Harvey dropped unprecedented rainfall over southeast Texas causing widespread flooding in the City of Houston. Water levels in the Addicks and Barker reservoirs, built in the 1940s to protect downtown Houston, exceeded previous records by approximately 2 meters. Concerns regarding structural integrity of the dams and damage to neighbourhoods in within the reservoir pool resulted in controlled releases into Buffalo Bayou, flooding an estimated 4,000 additional structures downstream of the dams. In 2016, during the Tax Day it became apparent that overflows from Cypress Creek in northern Harris County substantially contribute to water levels in Addicks. Prior to this event, little was known about the hydrodynamics of this overflow area or about the additional stress placed on Addicks and Barker reservoirs due to the volume of overflow. However, this information is critical for determining flood risk in Addicks Watershed, and ultimately Buffalo Bayou. In this study, we utilize the recently developed HEC-RAS 2D model the interbasin transfer that occurs between Cypress Creek Watershed and Addicks Reservoir to quantify the volume and rate at which water from Cypress enters the reservoir during extreme events. Ultimately, the results of this study will help inform the official hydrologic models used by HCFCD to determine reservoir operation during future storm events and better inform residents living in or above the reservoir pool about their potential flood risk.

  17. Examination of the Reelfoot Rift Petroleum System, south-central United States, and the elements that remain for potential exploration and development

    Science.gov (United States)

    Coleman, James; Pratt, Thomas L.

    2016-01-01

    The Reelfoot rift is one segment of a late Proterozoic(?) to early Paleozoic intracontinental rift complex in the south-central United States. The rift complex is situated beneath Mesozoic to Cenozoic strata of the Mississippi embayment of southeastern Missouri, northeastern Arkansas, and western Tennessee and Kentucky. The rift portion of the stratigraphic section consists primarily of synrift Cambrian and Ordovician strata, capped by a postrift sag succession of Late Ordovician to Cenozoic age. Potential synrift source rocks have been identified in the Cambrian Elvins Shale. Thermal maturity of Paleozoic strata within the rift ranges from the oil window to the dry gas window. Petroleum generation in Elvins source rocks likely occurred during the middle to late Paleozoic. Upper Cretaceous sedimentary rocks unconformably overlie various Paleozoic units and define the likely upper boundary of the petroleum system.

  18. Acoustic Identification of Individuals within Large Avian Populations: A Case Study of the Brownish-Flanked Bush Warbler, South-Central China

    Science.gov (United States)

    Xia, Canwei; Lin, Xuanlong; Liu, Wei; Lloyd, Huw; Zhang, Yanyun

    2012-01-01

    Acoustic identification is increasingly being used as a non-invasive method for identifying individuals within avian populations. However, most previous studies have utilized small samples of individuals (Warbler (Cettia fortipes) in the Dongzhai National Nature Reserve, south-central China. Most spectro-temporal variables we measured show greater variation among individuals than within individual. Although there was slight decline in the correct rate of individual identification with increasing sample sizes, the total mean correct rate yielded by discriminant function analysis was satisfactory, with more than 98% of songs correctly recognized to the corresponding individuals. We also found that using a part of randomly selected measured variables was sufficient to obtain a high correct rate of individual identification. We believe that our work will increase confidence in the use of using acoustic recognition techniques for avian population monitoring programs. PMID:22880018

  19. Discovery of microscopic evidence for shock metamorphism at the Serpent Mound structure, south-central Ohio: Confirmation of an origin by impact

    Science.gov (United States)

    Carlton, R.W.; Koeberl, C.; Baranoski, M.T.; SchuMacHer, G.A.

    1998-01-01

    The origin of the Serpent Mound structure in south-central Ohio has been disputed for many years. Clearly, more evidence was needed to resolve the confusion concerning the origin of the Serpent Mound feature either by endogenic processes or by hypervelocity impact. A petrographic study of 21 samples taken from a core 903 m long drilled in the central uplift of the structure provides evidence of shock metamorphism in the form of multiple sets of planar deformation features in quartz grains, as well as the presence of clasts of altered impact-melt rock. Crystallographic orientations of the planar deformation features show maxima at the shock-characteristic planes of {101??3} and {101??2} and additional maxima at {101??1}, {213??1}, and {516??1}. Geochemical analyses of impact breccias show minor enrichments in the abundances of the siderophile elements Cr, Co, Ni, and Ir, indicating the presence of a minor meteoritic component.

  20. Distribution and Diversity of Pathogenic Leptospira Species in Peri-domestic Surface Waters from South Central Chile.

    Science.gov (United States)

    Mason, Meghan R; Encina, Carolina; Sreevatsan, Srinand; Muñoz-Zanzi, Claudia

    2016-08-01

    Leptospirosis is a neglected zoonosis affecting animals and humans caused by infection with Leptospira. The bacteria can survive outside of hosts for long periods of time in soil and water. While identification of Leptospira species from human cases and animal reservoirs are increasingly reported, little is known about the diversity of pathogenic Leptospira species in the environment and how surveillance of the environment might be used for monitoring and controlling disease. Water samples (n = 104) were collected from the peri-domestic environment of 422 households from farms, rural villages, and urban slums participating in a broader study on the eco-epidemiology of leptospirosis in the Los Rios Region, Chile, between October 2010 and April 2012. The secY region of samples, previously detected as pathogenic Leptospira by PCR, was amplified and sequenced. Sequences were aligned using ClustalW in MEGA, and a minimum spanning tree was created in PHYLOViZ using the goeBURST algorithm to assess sequence similarity. Sequences from four clinical isolates, 17 rodents, and 20 reference strains were also included in the analysis. Overall, water samples contained L. interrogans, L. kirschneri, and L. weilii, with descending frequency. All species were found in each community type. The distribution of the species differed by the season in which the water samples were obtained. There was no evidence that community-level prevalence of Leptospira in dogs, rodents, or livestock influenced pathogen diversity in the water samples. This study reports the presence of pathogenic Leptospira in the peri-domestic environment of households in three community types and the differences in Leptospira diversity at the community level. Systematic environmental surveillance of Leptospira can be used for detecting changes in pathogen diversity and to identify and monitor contaminated areas where an increased risk of human infection exists.

  1. Reconstructing depositional processes and history from reservoir stratigraphy: Englebright Lake, Yuba River, northern California

    Science.gov (United States)

    Snyder, N.P.; Wright, S.A.; Alpers, Charles N.; Flint, L.E.; Holmes, C.W.; Rubin, D.M.

    2006-01-01

    Reservoirs provide the opportunity to link watershed history with its stratigraphic record. We analyze sediment cores from a northern California reservoir in the context of hydrologic history, watershed management, and depositional processes. Observations of recent depositional patterns, sediment-transport calculations, and 137CS geochronology support a conceptual model in which the reservoir delta progrades during floods of short duration (days) and is modified during prolonged (weeks to months) drawdowns that rework topset beds and transport sand from topsets to foresets. Sediment coarser than 0.25-0.5 mm. deposits in foresets and topsets, and finer material falls out of suspension as bottomset beds. Simple hydraulic calculations indicate that fine sand (0.063-0.5 mm) is transported into the distal bottomset area only during floods. The overall stratigraphy suggests that two phases of delta building occurred in the reservoir. The first, from dam construction in 1940 to 1970, was heavily influenced by annual, prolonged >20 m drawdowns of the water level. The second, built on top of the first, reflects sedimentation from 1970 to 2002 when the influence of drawdowns was less. Sedimentation rates in the central part of the reservoir have declined ???25% since 1970, likely reflecting a combination of fewer large floods, changes in watershed management, and winnowing of stored hydraulic mining sediment. Copyright 2006 by the American Geophysical Union.

  2. Glaciolacustrine deposits formed in an ice-dammed tributary valley in the south-central Pyrenees: New evidence for late Pleistocene climate

    Science.gov (United States)

    Sancho, Carlos; Arenas, Concha; Pardo, Gonzalo; Peña-Monné, José Luis; Rhodes, Edward J.; Bartolomé, Miguel; García-Ruiz, José M.; Martí-Bono, Carlos

    2018-04-01

    Combined geomorphic features, stratigraphic characteristics and sedimentologic interpretation, coupled with optically stimulated luminescence (OSL) dates, of a glacio-fluvio-lacustrine sequence (Linás de Broto, northern Spain) provide new information to understand the palaeoenvironmental significance of dynamics of glacier systems in the south-central Pyrenees during the Last Glacial Cycle (≈130 ka to 14 ka). The Linás de Broto depositional system consisted of a proglacial lake fed primarily by meltwater streams emanating from the small Sorrosal glacier and dammed by a lateral moraine of the Ara trunk glacier. The resulting glacio-fluvio-lacustrine sequence, around 55 m thick, is divided into five lithological units consisting of braided fluvial (gravel deposits), lake margin (gravel and sand deltaic deposits) and distal lake (silt and clay laminites) facies associations. Evolution of the depositional environment reflects three phases of progradation of a high-energy braided fluvial system separated by two phases of rapid expansion of the lake. Fluvial progradation occurred during short periods of ice melting. Lake expansion concurred with ice-dam growth of the trunk glacier. The first lake expansion occurred over a time range between 55 ± 9 ka and 49 ± 11 ka, and is consistent with the age of the Viu lateral moraine (49 ± 8 ka), which marks the maximum areal extent of the Ara glacier during the Last Glacial Cycle. These dates confirm that the maximum areal extent of the glacier occurred during Marine Isotope Stages 4 and 3 in the south-central Pyrenees, thus before the Last Glacial Maximum. The evolution of the Linás de Broto depositional system during this maximum glacier extent was modulated by climate oscillations in the northern Iberian Peninsula, probably related to latitudinal shifts of the atmospheric circulation in the southern North-Atlantic Ocean, and variations in summer insolation intensity.

  3. Observed and CMIP5 modeled influence of large-scale circulation on summer precipitation and drought in the South-Central United States

    Science.gov (United States)

    Ryu, Jung-Hee; Hayhoe, Katharine

    2017-12-01

    Annual precipitation in the largely agricultural South-Central United States is characterized by a primary wet season in May and June, a mid-summer dry period in July and August, and a second precipitation peak in September and October. Of the 22 CMIP5 global climate models with sufficient output available, 16 are able to reproduce this bimodal distribution (we refer to these as "BM" models), while 6 have trouble simulating the mid-summer dry period, instead producing an extended wet season ("EW" models). In BM models, the timing and amplitude of the mid-summer westward extension of the North Atlantic Subtropical High (NASH) are realistic, while the magnitude of the Great Plains Lower Level Jet (GPLLJ) tends to be overestimated, particularly in July. In EW models, temporal variations and geophysical locations of the NASH and GPLLJ appear reasonable compared to reanalysis but their magnitudes are too weak to suppress mid-summer precipitation. During warm-season droughts, however, both groups of models reproduce the observed tendency towards a stronger NASH that remains over the region through September, and an intensification and northward extension of the GPLLJ. Similarly, future simulations from both model groups under a +1 to +3 °C transient increase in global mean temperature show decreases in summer precipitation concurrent with an enhanced NASH and an intensified GPLLJ, though models differ regarding the months in which these decreases are projected to occur: early summer in the BM models, and late summer in the EW models. Overall, these results suggest that projected future decreases in summer precipitation over the South-Central region appear to be closely related to anomalous patterns of large-scale circulation already observed and modeled during historical dry years, patterns that are consistently reproduced by CMIP5 models.

  4. Managing Watersheds as Couple Human-Natural Systems: A Review of Research Opportunities

    Science.gov (United States)

    Cai, X.

    2011-12-01

    Many watersheds around the world are impaired with severe social and environmental problems due to heavy anthropogenic stresses. Humans have transformed hydrological and biochemical processes in watersheds from a stationary to non-stationary status through direct (e.g., water withdrawals) and indirect (e.g., altering vegetation and land cover) interferences. It has been found that in many watersheds that socio-economic drivers, which have caused increasingly intensive alteration of natural processes, have even overcome natural variability to become the dominant factor affecting the behavior of watershed systems. Reversing this trend requires an understanding of the drivers of this intensification trajectory, and needs tremendous policy reform and investment. As stressed by several recent National Research Council (NRC) reports, watershed management will pose an enormous challenge in the coming decades. Correspondingly, the focus of research has started an evolution from the management of reservoir, stormwater and aquifer systems to the management of integrated watershed systems, to which policy instruments designed to make more rational economic use of water resources are likely to be applied. To provide a few examples: reservoir operation studies have moved from a local to a watershed scale in order to consider upstream best management practices in soil conservation and erosion control and downstream ecological flow requirements and water rights; watersheds have been modeled as integrated hydrologic-economic systems with multidisciplinary modeling efforts, instead of traditional isolated physical systems. Today's watershed management calls for a re-definition of watersheds from isolated natural systems to coupled human-natural systems (CHNS), which are characterized by the interactions between human activities and natural processes, crossing various spatial and temporal scales within the context of a watershed. The importance of the conceptual innovation has been

  5. Dynamic Processes of Large Wood and Their Effects on Fluvial Export at the Watershed Scale

    Science.gov (United States)

    Seo, J.; Nakamura, F.; Chun, K.

    2008-12-01

    The presence of large wood (LW) has a pronounced impact on the geomorphic and ecological character of river corridors, yet relatively little is known about the patterns and processes at the watershed scale. To understand these patterns we monitored the volumetric input of LW into 131 reservoirs and a suite of watershed characteristics. Of all geomorphic and hydrologic variables tested, watershed area was most important in explaining LW export. LW export per unit watershed area was relatively high in small watersheds, peaked in intermediate-sized watersheds and decreased in large watersheds. To explain these variations, we surveyed the amount of LW with respect to channel morphology in 78 segments (26 segments in each size class) in the Nukabira River, northern Japan, and examined the differences in LW dynamics, including its recruitment, transport, storage, and fragmentation and decay along the spectrum of watershed sizes. We found in small watersheds a larger proportion of LW produced by forest dynamics and hillslope processes was retained due to narrower valley floors and lower stream power. The retained LW pieces may eventually be exported during debris flows. In intermediate-sized watersheds the volume of LW pieces derived from hillslopes decreased substantially with reductions of proportion of channel length bordered by hillslope margins, which potentially deliver large quantities of LW. Because these channels have lower wood piece length to channel width ratios and higher stream power, LW pieces can be transported downstream. During transport, LW pieces are further fragmented and can be more easily transported; and therefore, the fluvial export of LW is maximized in intermediate-sized watersheds. Rivers in large watersheds, where the recruitment of LW is limited by the decreasing hillslope margins, cannot transport LW pieces because of their low stream power and thus LW pieces accumulate at various storage sites. Although these stored LW pieces can be re

  6. Application of the Precipitation Runoff Modeling System to measure impacts of forest fire on watershed hydrology

    Science.gov (United States)

    Driscoll, J. M.

    2015-12-01

    Precipitation in the southwestern United States falls primarily in areas of higher elevation. Drought conditions over the past five years have limited snowpack and rainfall, increasing the vulnerability to and frequency of forest fires in these montane regions. In June 2012, the Little Bear fire burned approximately 69 square miles (44,200 acres) in high-elevation forests of the Rio Hondo headwater catchments, south-central New Mexico. Burn severity was high or moderate on 53 percent of the burn area. The Precipitation Runoff Modeling System (PRMS) is a publically-available watershed model developed by the U.S. Geological Survey (USGS). PRMS data are spatially distributed using a 'Geospatial Fabric' developed at a national scale to define Hydrologic Response Units (HRUs), based on topography and points of interest (such as confluences and streamgages). The Little Bear PRMS study area is comprised of 22 HRUs over a 587 square-mile area contributing to the Rio Hondo above Chavez Canyon streamgage (USGS ID 08390020), in operation from 2008 to 2014. Model input data include spatially-distributed climate data from the National Aeronautics and Space Administration (NASA) DayMet and land cover (such as vegetation and soil properties) data from the USGS Geo Data Portal. Remote sensing of vegetation over time has provided a spatial distribution of recovery and has been applied using dynamic parameters within PRMS on the daily timestep over the study area. Investigation into the source and timing of water budget components in the Rio Hondo watershed may assist water planners and managers in determining how the surface-water and groundwater systems will react to future land use/land cover changes. Further application of PRMS in additional areas will allow for comparison of streamflow before and following wildfire conditions, and may lead to better understanding of the changes in watershed-scale hydrologic processes in the Southwest through post-fire watershed recovery.

  7. Alaska Index of Watershed Integrity

    Science.gov (United States)

    The US Environmental Protection Agency’s (EPA) Index of Watershed Integrity (IWI) is used to calculate and visualize the status of natural watershed infrastructure that supports ecological processes (e.g., nutrient cycling) and services provided to society (e.g., subsistenc...

  8. Global perspective of watershed management

    Science.gov (United States)

    Kenneth N. Brooks; Karlyn Eckman

    2000-01-01

    This paper discusses the role of watershed management in moving towards sustainable natural resource and agricultural development. Examples from 30 field projects and six training projects involving over 25 countries are presented to illustrate watershed management initiatives that have been implemented over the last half of the 20th century. The level of success has...

  9. HESS Opinions: Linking Darcy's equation to the linear reservoir

    Science.gov (United States)

    Savenije, Hubert H. G.

    2018-03-01

    In groundwater hydrology, two simple linear equations exist describing the relation between groundwater flow and the gradient driving it: Darcy's equation and the linear reservoir. Both equations are empirical and straightforward, but work at different scales: Darcy's equation at the laboratory scale and the linear reservoir at the watershed scale. Although at first sight they appear similar, it is not trivial to upscale Darcy's equation to the watershed scale without detailed knowledge of the structure or shape of the underlying aquifers. This paper shows that these two equations, combined by the water balance, are indeed identical provided there is equal resistance in space for water entering the subsurface network. This implies that groundwater systems make use of an efficient drainage network, a mostly invisible pattern that has evolved over geological timescales. This drainage network provides equally distributed resistance for water to access the system, connecting the active groundwater body to the stream, much like a leaf is organized to provide all stomata access to moisture at equal resistance. As a result, the timescale of the linear reservoir appears to be inversely proportional to Darcy's conductance, the proportionality being the product of the porosity and the resistance to entering the drainage network. The main question remaining is which physical law lies behind pattern formation in groundwater systems, evolving in a way that resistance to drainage is constant in space. But that is a fundamental question that is equally relevant for understanding the hydraulic properties of leaf veins in plants or of blood veins in animals.

  10. Decision Support System for Reservoir Management and Operation in Africa

    Science.gov (United States)

    Navar, D. A.

    2016-12-01

    Africa is currently experiencing a surge in dam construction for flood control, water supply and hydropower production, but ineffective reservoir management has caused problems in the region, such as water shortages, flooding and loss of potential hydropower generation. Our research aims to remedy ineffective reservoir management by developing a novel Decision Support System(DSS) to equip water managers with a technical planning tool based on the state of the art in hydrological sciences. The DSS incorporates a climate forecast model, a hydraulic model of the watershed, and an optimization model to effectively plan for the operation of a system of cascade large-scale reservoirs for hydropower production, while treating water supply and flood control as constraints. Our team will use the newly constructed hydropower plants in the Omo Gibe basin of Ethiopia as the test case. Using the basic HIDROTERM software developed in Brazil, the General Algebraic Modeling System (GAMS) utilizes a combination of linear programing (LP) and non-linear programming (NLP) in conjunction with real time hydrologic and energy demand data to optimize the monthly and daily operations of the reservoir system. We compare the DSS model results with the current reservoir operating policy used by the water managers of that region. We also hope the DSS will eliminate the current dangers associated with the mismanagement of large scale water resources projects in Africa.

  11. Map Showing Geologic Terranes of the Hailey 1°x2° Quadrangle and the western part of the Idaho Falls 1°x2° Quadrangle, south-central Idaho

    Data.gov (United States)

    Department of the Interior — The paper version of Map Showing Geologic Terranes of the Hailey 1°x2° Quadrangle and the western part of the Idaho Falls 1°x2° Quadrangle, south-central Idaho was...

  12. Environmental Impact Assessment of reservoir construction: new perspectives for restoration economy, and development: the Belo Monte Power Plant case study.

    Science.gov (United States)

    Tundisi, J G; Matsumura-Tundisi, T; Tundisi, J E M

    2015-08-01

    The Environmental Impact Assessment of reservoir construction can be viewed as a new strategic perspective for the economic development of a region. Based on the principles of a watershed approach a interdisciplinary and multidisciplinary systemic view including biogeophysiographical, economic and socio environmental studies the new vision of a EIA provides a basic substratum for the restoration economy and an advanced model for the true development much well ahead of the modernization aspects of the project of a reservoir construction.

  13. Rainfall prediction of Cimanuk watershed regions with canonical correlation analysis (CCA)

    Science.gov (United States)

    Rustiana, Shailla; Nurani Ruchjana, Budi; Setiawan Abdullah, Atje; Hermawan, Eddy; Berliana Sipayung, Sinta; Gede Nyoman Mindra Jaya, I.; Krismianto

    2017-10-01

    Rainfall prediction in Indonesia is very influential on various development sectors, such as agriculture, fisheries, water resources, industry, and other sectors. The inaccurate predictions can lead to negative effects. Cimanuk watershed is one of the main pillar of water resources in West Java. This watersheds divided into three parts, which is a headwater of Cimanuk sub-watershed, Middle of Cimanuk sub-watershed and downstream of Cimanuk sub- watershed. The flow of this watershed will flow through the Jatigede reservoir and will supply water to the north-coast area in the next few years. So, the reliable model of rainfall prediction is very needed in this watershed. Rainfall prediction conducted with Canonical Correlation Analysis (CCA) method using Climate Predictability Tool (CPT) software. The prediction is every 3months on 2016 (after January) based on Climate Hazards group Infrared Precipitation with Stations (CHIRPS) data over West Java. Predictors used in CPT were the monthly data index of Nino3.4, Dipole Mode (DMI), and Monsoon Index (AUSMI-ISMI-WNPMI-WYMI) with initial condition January. The initial condition is chosen by the last data update. While, the predictant were monthly rainfall data CHIRPS region of West Java. The results of prediction rainfall showed by skill map from Pearson Correlation. High correlation of skill map are on MAM (Mar-Apr-May), AMJ (Apr-May-Jun), and JJA (Jun-Jul-Aug) which means the model is reliable to forecast rainfall distribution over Cimanuk watersheds region (over West Java) on those seasons. CCA score over those season prediction mostly over 0.7. The accuracy of the model CPT also indicated by the Relative Operating Characteristic (ROC) curve of the results of Pearson correlation 3 representative point of sub-watershed (Sumedang, Majalengka, and Cirebon), were mostly located in the top line of non-skill, and evidenced by the same of rainfall patterns between observation and forecast. So, the model of CPT with CCA method

  14. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...... driftsstrategier kan erstattes af optimale strategier baseret på den nyeste udvikling indenfor computer-baserede beregninger. Hovedbidraget i afhandlingen er udviklingen af et beregningssystem, hvori en simuleringsmodel er koblet til en model for optimering af nogle udvalgte beslutningsvariable, der i særlig grad...

  15. Integrating operational watershed and coastal models for the Iberian Coast: Watershed model implementation - A first approach

    Science.gov (United States)

    Brito, David; Campuzano, F. J.; Sobrinho, J.; Fernandes, R.; Neves, R.

    2015-12-01

    River discharges and loads are essential inputs to coastal seas, and thus for coastal seas modelling, and their properties are the result of all activities and policies carried inland. For these reasons main rivers were object of intense monitoring programs having been generated some important amount of historical data. Due to the decline in the Portuguese hydrometric network and in order to quantify and forecast surface water streamflow and nutrients to coastal areas, the MOHID Land model was applied to the Western Iberia Region with a 2 km horizontal resolution and to the Iberian Peninsula with 10 km horizontal resolution. The domains were populated with land use and soil properties and forced with existing meteorological models. This approach also permits to understand how the flows and loads are generated and to forecast their values which are of utmost importance to perform coastal ocean and estuarine forecasts. The final purpose of the implementation is to obtain fresh water quantity and quality that could be used to support management decisions in the watershed, reservoirs and also to estuaries and coastal areas. A process oriented model as MOHID Land is essential to perform this type of simulations, as the model is independent of the number of river catchments. In this work, the Mohid Land model equations and parameterisations were described and an innovative methodology for watershed modelling is presented and validated for a large international river, the Tagus River, and the largest national river of Portugal, the Mondego River. Precipitation, streamflow and nutrients modelling results for these two rivers were compared with observations near their coastal outlet in order to evaluate the model capacity to represent the main watershed trends. Finally, an annual budget of fresh water and nutrient transported by the main twenty five rivers discharging in the Portuguese coast is presented.

  16. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  17. Session: Reservoir Technology

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  18. Watershed-based survey designs

    Science.gov (United States)

    Detenbeck, N.E.; Cincotta, D.; Denver, J.M.; Greenlee, S.K.; Olsen, A.R.; Pitchford, A.M.

    2005-01-01

    Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream–downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs.

  19. Impact of Water Usage on the Hydrology of Streams in the Mill River Watershed, Massachusetts

    Science.gov (United States)

    Newton, R. M.; Rhodes, A. L.; Pufall, A.; Bradstreet, E.; Katchpole, S.; Mattison, E.; Woods, R.

    2001-05-01

    Removal of surface water for municipal water supplies has reduced base flow in two tributary streams to the Mill River in Whately Massachusetts. This reduction in the flow of high quality water from these tributaries reduces the amount of dilution of high anthropogenic chemical loads in the main branch of the Mill River leading to high concentrations of chloride and sulfate. The city of Northampton, operates a reservoir on West Brook that removes an average of 5,700 m3/day. West Brook occupies a 28.4 km2 watershed underlain by Paleozoic igneous and metamorphic rocks that are mainly overlain by thin deposits of Pleistocene till. There are isolated areas of stratified drift in the area of the reservoir and where West Brook enters into the area formerly occupied by Glacial Lake Hitchcock. The reservoir (0.35 km2 in area) lies within the upper third of the subcatchment and is primarily fed by Avery Brook (7.6 km2 watershed). Although the reservoirs watershed represent about one third of the West Brook watershed, high water demands limit the release of water from the reservoir to periods of high flow associated with intense rainfall or snowmelt events. A comparison of unit hydrographs from Avery Brook, upstream of the reservoir with those from West Brook near where it enters the Mill River show significant lower discharges downstream (1mm/day). A comparison of flow duration curves show that discharges below the reservoir are dramatically lower during low flow conditions. The town of South Deerfield operates a reservoir on Roaring Brook that removes approximately 3,800 m3/day. Roaring Brook occupies a 14.0 km2 watershed that is similar in geology to West Brook. The reservoir is located on the downstream section of the brook just above where it enters the Mill River. Unlike the Northampton reservoir, water is almost continually released from the reservoir although the rate does fluctuate greatly. Data from a gage station located just downstream of the dam show rapid

  20. Scope and Limits of an anamnestic questionnaire in a control-induced low-endemicity helminthiasis setting in south-central Côte d'Ivoire.

    Directory of Open Access Journals (Sweden)

    Thomas Fürst

    Full Text Available BACKGROUND: Schistosomiasis and soil-transmitted helminthiasis are two high-burden neglected tropical diseases. In highly endemic areas, control efforts emphasize preventive chemotherapy. However, as morbidity, infection, and transmission begin to decrease, more targeted treatment is likely to become more cost-effective, provided that comparatively cheap diagnostic methods with reasonable accuracy are available. METHODOLOGY: Adults were administered an anamnestic questionnaire in mid-2010 during a cross-sectional epidemiological survey in the Taabo health demographic surveillance system in south-central Côte d'Ivoire. Questions pertaining to risk factors and signs and symptoms for schistosomiasis and soil-transmitted helminthiasis were included. The individuals' helminth infection status and their belonging to three different anthelmintic treatment groups were compared with the questionnaire results (i to inform the local health authorities about the epidemiological and clinical footprint of locally prevailing helminthiases, and (ii to explore the scope and limits of an anamnestic questionnaire as monitoring tool, which eventually could help guiding the control of neglected tropical diseases in control-induced low-endemicity settings. PRINCIPAL FINDINGS: Our study sample consisted of 195 adults (101 males, 94 females. We found prevalences of hookworm, Trichuris trichiura, Schistosoma haematobium, and Schistosoma mansoni of 39.0%, 2.7%, 2.1%, and 2.1%, respectively. No Ascaris lumbricoides infection was found. Helminth infection intensities were generally very low. Seven, 74 and 79 participants belonged to three different treatment groups. Multivariable logistic regression models revealed statistically significant (p<0.05 associations between some risk factors, signs, and symptoms, and the different helminth infections and treatment groups. However, the risk factors, signs, and symptoms showed weak diagnostic properties. CONCLUSIONS

  1. The Biology of the Triatomine Bugs Native to South Central Texas and Assessment of the Risk They Pose for Autochthonous Chagas Disease Exposure.

    Science.gov (United States)

    Wozniak, Edward J; Lawrence, Gena; Gorchakov, Rodion; Alamgir, Hasanat; Dotson, Ellen; Sissel, Blake; Sarkar, Sahotra; Murray, Kristy O

    2015-10-01

    Triatomine bugs are a group of hematophagous arthropods that can serve as biological vectors for Trypanosoma cruzi , the etiological agent of American trypanosomiasis (Chagas disease). Because of differences in the biology and feeding habits among triatomine species, some are more likely than others to be involved in zoonotic and/or human-to-human transmission cycles of T. cruzi . In an attempt to assess the risk for Chagas disease exposure in south-central Texas, human habitations across Texas Health Service Region 8 (HSR 8) and surrounding counties were surveyed for triatomines to characterize the geographic distribution, species-specific biology, and T. cruzi -infection prevalence better. Between May 2010 and August 2013, a total of 545 triatomines representing all 5 known indigenous species (Triatoma gerstaeckeri, Triatoma indictiva, Triatoma lecticularia, Triatoma sanguisuga, and Triatoma protracta woodi) were collected from 59 sites across the region. Triatoma gerstaeckeri was the species most commonly found in domestic and peridomestic ecotopes across Texas HSR 8, representing over 80% of the triatomines collected. Adult T. gerstaeckeri exhibited a seasonal dispersal pattern that began in late April, peaked in mid-May, and then continued into August. On homes with available crevices in the exterior walls, adult T. gerstaeckeri were observed emerging from or entering these protective microhabitats, suggesting possible opportunistic colonization of some exterior walls compartments. Laboratory testing of triatomine hindgut contents for T. cruzi by PCR demonstrated the adult T. gerstaeckeri-infection prevalence across Texas HSR 8 to be 64%. Monitoring peridomestic adult T. gerstaeckeri over the seasonal dispersal peak demonstrated statistically significant increases in both their T. cruzi -infection prevalence (P tendency to invade human dwellings (P tendencies. The high prevalence of T. cruzi infection in native triatomines, and the high frequency with which T

  2. Wellspring characteristics in Rawapening watershed

    Science.gov (United States)

    Hafidah, A. D.; Damayanti, A.; Waryono, T.

    2017-07-01

    Rawapening watershed is formed in a volcanic region and is the headwater of Tuntang River that disembogues into Rawa Pening Lake. Rawa Pening Lake was formed due to gravitational tectonic events that form many faults and folds. Those events result in aquifers that create many wellsprings in Rawapening watershed. This research is conducted to determine the wellsprings distribution based on physical characteristics of the discharge area and the types of wellsprings in Rawapening watershed. Associative and descriptive analysis are used to explain the wellsprings' condition based on height, slopeness, geological formation, and the soil utilization.

  3. Comparison of the Prevalences and Diversities of Listeria Species and Listeria monocytogenes in an Urban and a Rural Agricultural Watershed.

    Science.gov (United States)

    Stea, Emma C; Purdue, Laura M; Jamieson, Rob C; Yost, Chris K; Truelstrup Hansen, Lisbeth

    2015-06-01

    Foods and related processing environments are commonly contaminated with the pathogenic Listeria monocytogenes. To investigate potential environmental reservoirs of Listeria spp. and L. monocytogenes, surface water and point source pollution samples from an urban and a rural municipal water supply watershed in Nova Scotia, Canada, were examined over 18 months. Presumptive Listeria spp. were cultured from 72 and 35% of rural and urban water samples, respectively, with 24% of the positive samples containing two or three different Listeria spp. The L. innocua (56%) and L. welshimeri (43%) groups were predominant in the rural and urban watersheds, respectively. Analysis by the TaqMan assay showed a significantly (P Listeria spp. were associated with 70 times higher odds of isolating L. monocytogenes (odds ratio = 70; P Listeria species population and could be a potential reservoir for L. monocytogenes, especially in rural agricultural watersheds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  5. Parallel reservoir simulator computations

    International Nuclear Information System (INIS)

    Hemanth-Kumar, K.; Young, L.C.

    1995-01-01

    The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

  6. Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Jha

    2011-06-01

    Full Text Available This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS. Meteorological input, including precipitation and temperature from six weather stations located in and around the watershed, and measured streamflow data at the watershed outlet, were used in the simulation. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and baseflow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model was found to explain at least 86% and 69% of the variability in the measured streamflow data for calibration and validation periods, respectively. This initial hydrologic assessment will facilitate future modeling applications using SWAT to the Maquoketa River watershed for various watershed analyses, including watershed assessment for water quality management, such as total maximum daily loads, impacts of land use and climate change, and impacts of alternate management practices.

  7. GIBSI: an integrated modelling system for watershed management – sample applications and current developments

    Directory of Open Access Journals (Sweden)

    A. N. Rousseau

    2007-11-01

    Full Text Available Hydrological and pollutant fate models have long been developed for research purposes. Today, they find an application in integrated watershed management, as decision support systems (DSS. GIBSI is such a DSS designed to assist stakeholders in watershed management. It includes a watershed database coupled to a GIS and accessible through a user-friendly interface, as well as modelling tools that simulate, on a daily time step, hydrological processes such as evapotranspiration, runoff, soil erosion, agricultural pollutant transport and surface water quality. Therefore, GIBSI can be used to assess a priori the effect of management scenarios (reservoirs, land use, waste water effluents, diffuse sources of pollution that is agricultural pollution on surface hydrology and water quality. For illustration purposes, this paper presents several management-oriented applications using GIBSI on the 6680 km2 Chaudière River watershed, located near Quebec City (Canada. They include impact assessments of: (i municipal clean water program; (ii agricultural nutrient management scenarios; (iii past and future land use changes, as well as (iv determination of achievable performance standards of pesticides management practices. Current and future developments of GIBSI are also presented as these will extend current uses of this tool and make it useable and applicable by stakeholders on other watersheds. Finally, the conclusion emphasizes some of the challenges that remain for a better use of DSS in integrated watershed management.

  8. Values, Watersheds and Justification

    DEFF Research Database (Denmark)

    Wiberg, Katrina

    2015-01-01

    The aim of this paper is to articulate and present some arguments for the following main hypothesis concerning the handling of water (HOW) in the urban landscapes of our times of climate change. During industrialism water in urban areas to a very high degree was handled by ‘undergrounding......’ it in systems of water provision, sewagesystems etc. Under conditions of climate change this ‘undergrounding’ approach has shown its limitations. In extreme weather conditions water is ‘resurfacing’ which creates both problems and a new condition of HOW in urban landscapes. Problems of water cannot be ‘buried......’ anymore; they also have to be handled at surface levels. This has two interconnected implications: firstly, watersheds gains new importance for HOW at surface-levels, and secondly, such surfacing of water problems leads to a rise in the potential levels of value-disputes and conflicts of interest...

  9. Effects of residential and agricultural land uses on the chemical quality of baseflow of small streams in the Croton Watershed, southeastern New York

    Science.gov (United States)

    Heisig, Paul M.

    2000-01-01

    Data on the chemical quality of baseflow from 33 small streams that drain basins of differing land-use type and intensity within the Croton watershed were collected seasonally for 1 year to identify and characterize the quality of ground-water contributions to surface water. The watershed includes twelve of New York City's water-supply reservoirs. Baseflow samples were collected a minimum of three days after the most recent precipitation and were analyzed for major ions, boron, and nutrients.

  10. Asotin Creek Model Watershed Plan

    Energy Technology Data Exchange (ETDEWEB)

    Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

    1995-04-01

    The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

  11. The water-quality monitoring program for the Baltimore reservoir system, 1981-2007—Description, review and evaluation, and framework integration for enhanced monitoring

    Science.gov (United States)

    Koterba, Michael T.; Waldron, Marcus C.; Kraus, Tamara E.C.

    2011-01-01

    The City of Baltimore, Maryland, and parts of five surrounding counties obtain their water from Loch Raven and Liberty Reservoirs. A third reservoir, Prettyboy, is used to resupply Loch Raven Reservoir. Management of the watershed conditions for each reservoir is a shared responsibility by agreement among City, County, and State jurisdictions. The most recent (2005) Baltimore Reservoir Watershed Management Agreement (RWMA) called for continued and improved water-quality monitoring in the reservoirs and selected watershed tributaries. The U.S. Geological Survey (USGS) conducted a retrospective review of the effectiveness of monitoring data obtained and analyzed by the RWMA jurisdictions from 1981 through 2007 to help identify possible improvements in the monitoring program to address RWMA water-quality concerns. Long-term water-quality concerns include eutrophication and sedimentation in the reservoirs, and elevated concentrations of (a) nutrients (nitrogen and phosphorus) being transported from the major tributaries to the reservoirs, (b) iron and manganese released from reservoir bed sediments during periods of deep-water anoxia, (c) mercury in higher trophic order game fish in the reservoirs, and (d) bacteria in selected reservoir watershed tributaries. Emerging concerns include elevated concentrations of sodium, chloride, and disinfection by-products (DBPs) in the drinking water from both supply reservoirs. Climate change and variability also could be emerging concerns, affecting seasonal patterns, annual trends, and drought occurrence, which historically have led to declines in reservoir water quality. Monitoring data increasingly have been used to support the development of water-quality models. The most recent (2006) modeling helped establish an annual sediment Total Maximum Daily Load to Loch Raven Reservoir, and instantaneous and 30-day moving average water-quality endpoints for chlorophyll-a (chl-a) and dissolved oxygen (DO) in Loch Raven and Prettyboy

  12. Stable sulfur and oxygen isotope ratios of the Świętokrzyski National Park spring waters generated by natural and anthropogenic factors (south-central Poland)

    International Nuclear Information System (INIS)

    Michalik, Artur; Migaszewski, Zdzisław M.

    2012-01-01

    This paper presents the results of an isotopic study of spring waters in Świętokrzyski (Holy Cross Mountain) National Park (ŚNP), south-central Poland. The δ 34 S V-CDT and δ 18 O V-SMOW of soluble sulfates (n = 40) varied from 0.5‰ to 18.1‰ and from 3.5‰ to 12.2‰, respectively. The average δ 34 S values are closely similar to those of rainwater, soils and rocks (comprising scattered pyrite). This suggests that soluble sulfates in the springs originated from mixing of recent and historic deposition, sulfates derived from pyrite oxidation, and CS-mineralization in soils and debris. An additional anthropogenic sulfur input (inorganic fertilizer) occurs in the water of spring S-61 located in the Świętokrzyski National Park buffer zone. The δ 18 O V-SMOW of spring waters (n = 4) were in the range of −10.6‰ to −10.2‰ indicating that they are derived from vadose groundwater in ŚNP. This was the first isotope study of spring waters in the national parks of Poland. It enabled the determination of sulfur pathways and discrimination between natural and anthropogenic sources of this element in a relatively pristine area.

  13. Vegetative Propagation Trial of Prosopis africana (Guill. et Perr. Taub. by Air Layering under Sudano-Sahelian Climate in the South-Central Niger

    Directory of Open Access Journals (Sweden)

    Laouali Abdou

    2015-01-01

    Full Text Available Prosopis africana is a species of great socioeconomic importance but threatened with extinction in Niger because of overuse and regeneration problem. This study, conducted in the Maradi (Niger area, precisely at El Gueza in the south of Gazaoua department, aims to evaluate the vegetative propagation capacity of P. africana by air layering under the Sudano-Sahelian climate of the south-central Niger. A ring of bark was taken on each selected branch and the wound was covered with a black plastic filled with a damp mixture of soil and wood debris. The chosen parameters are the diameter class and the position on the branch. In all, 60 branches were treated and followed for 130 days: 28.33% produced shoots and there was no significant difference between the diameter classes and between the positions. These results show that propagating trees of the species by air layering is possible and this technique can be used to multiply and keep this species, which will reduce the regeneration problem linked to a low seed germination rate.

  14. Toponymic Data Helps to Reveal the Occurrence of Previously Unknown Populations of Wild Zamia pumila L. on Volcanic Substrates in South Central Puerto Rico

    Directory of Open Access Journals (Sweden)

    Jaime R. Pagán-Jiménez

    2013-03-01

    Full Text Available This is the first report of the occurrence of wild Zamia pumila L. Zamiaceae populations on various volcanic substrates in the piedmont area of south central Puerto Rico. Data acquisition and its field confirmation were possible after the identification of toponymic names in old and current maps, and historic documents of the island in which one of the indigenous names for the genus (marunguey [marungüey] or marungueyes has been used for naming some localities. These preliminary data have deep implications for paleo- and neoethnobotanical research, and for population ecology of the species in Puerto Rico, because they expand the traditionally accepted range for the species on the island. Zamia has been described as one of the main food plants among pre- and post-Columbian inhabitants in two islands of the Greater Antilles, Hispaniola and Puerto Rico, where the most sophisticated pre-Columbian society of the Antilles, the Taínos, emerged. Our findings suggest that Zamia might have been more available to humans, as a food source, than previously thought. 

  15. Lead poisoning of children in Africa. Part 4. Exposure to dust lead in primary schools in south-central Durban, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Liggans, Girvin L.; Nriagu, Jerome O. [Department of Environmental and Industrial Health, School of Public Health, University of Michigan, 109 Observatory, Ann Arbor (United States)

    1998-10-08

    Twenty primary schools in three areas (Merebank, Austerville and Bluff) of south-central Durban, South Africa were studied to determine if dust lead loading ({mu}g/m{sup 2}) is high enough to constitute a risk to children. Atmospheric lead fallout rates in the schools varied from 9 to 264 {mu}g/m{sup 2} per day and are higher than the values now being reported in the developed countries. Mean outside dust lead loadings were 425 {mu}g/m{sup 2} in Merebank, 771 {mu}g/m{sup 2} in Austerville and 1174 {mu}g/m{sup 2} in Bluff areas, and 25% of the primary schools were found to have mean outside dust lead loading above 1000 {mu}g/m{sup 2}. Mean dust lead loadings inside classrooms were 2-4 times lower than the outside rates, and showed no significant difference among schools in the three areas. Dust lead loadings were correlated with lead concentrations in dust but not with distance from the highway or with atmospheric lead deposition rates. Exposure to dust lead in classrooms and in the school yard is considered to be an important contributor to blood lead levels in, and hence a potential health hazard to, children in many urban areas of the country

  16. Geology and taphonomy of the L'Espinau dinosaur bonebed, a singular lagoonal site from the Maastrichtian of South-Central Pyrenees

    Science.gov (United States)

    Fondevilla, V.; Vicente, A.; Battista, F.; Sellés, A. G.; Dinarès-Turell, J.; Martín-Closas, C.; Anadón, P.; Vila, B.; Razzolini, N. L.; Galobart, À.; Oms, O.

    2017-06-01

    The L'Espinau site is a dinosaur bonebed from the Upper Cretaceous of the South-Central Pyrenees (north-eastern Spain) that have provided hundreds of bone remains attributed to hadrosauroids, together with a rich assemblage of herpetofauna, fish and microflora. Magnetostratigraphy calibrated the site with the early late Maastrichtian, and the combined sedimentology, stable isotope geochemistry and palaeoecology revealed that this fossil site formed in a lagoon, in which a mixed freshwater-brackish palaeoenvironment was developed. This setting displays a south-north charophyte zonation from freshwater (Clavator brachycerus-dominated assemblage) to brackish or eurihaline conditions (Feistiella malladae-dominated assemblage), revealing a palaeoenvironment change towards the coast. Sedimentology and taphonomy (bidirectional arrangement of long bones, abrasion and disarticulation) indicate that the L'Espinau site is the result of a cohesive mass flow event originated very close to the sea. This process entrained and mixed fauna from both the terrestrial and the brackish/marine environment of a lagoon. An increasing of the water runoff (e.g. by intense rainfall) reworking poorly consolidated sediments is considered here as the most probable triggering mechanism. Mass flow-hosted bonebeds are commonly linked to fluvial palaeoenvironments, so our study case is a rare example of bones accumulating near the sea. This study adds evidence that hadrosauroids inhabited littoral environments during the Maastrichtian in the southern Pyrenean area.

  17. Discovery of modern (post-1850 CE) lavas in south-central British Columbia, Canada: Origin from coal fires or intraplate volcanism?

    Science.gov (United States)

    Canil, Dante; Mihalynuk, Mitch; Lacourse, Terri

    2018-01-01

    We describe three unusual lavas in the Northern Cordillera in south-central British Columbia, Canada, occurring as spatter, scoria and blocks over small 400 m2 areas. The lavas coat and weld cobbles and pebbles in glacial till and are vesicular and glassy with microlites of clinopyroxene and plagioclase, and xenocrysts of quartz, feldspar or clinopyroxene. Chemically the lavas are basaltic trachyandesite (55-61 wt% SiO2) with trace element patterns similar to average British Columbia upper crust, except for having higher V and lower Zr, Hf, Nb, Th and U. Melting experiments and plagioclase-melt thermometry on the glasses, and phase equilibrium in simple systems, require liquidus temperatures of 1150-1300 °C. Interaction of the liquids with carbonaceous matter at low pressure formed Fe metal spherules and SiC. Radiocarbon ages of charcoal and dendrochronology show the lavas are modern, emplaced in the last 120 years. The similar bulk composition of these lavas to several other Quaternary-aged volcanic centers in the North American Cordillera, some of which show recent seismic activity, could suggest a possible tectonic origin, but the deposits are unusually small and show no central vent for emplacement. Conversely, the balance of evidence would suggest an origin from coal fires or hot gas venting, but is less consistent with the observed calc- and per-alkaline lava compositions, and the lack of known local coal-bearing strata as a heat source. Other anthropogenic origins for the lavas are considered less plausible.

  18. PAH fluxes in the Laja Lake of south central Chile Andes over the last 50 years: Evidence from a dated sediment core

    International Nuclear Information System (INIS)

    Quiroz, Roberto; Popp, Peter; Urrutia, Roberto; Bauer, Coretta; Araneda, Alberto; Treutler, Hanns-Christian; Barra, Ricardo

    2005-01-01

    This paper reports the occurrence of polyaromatic hydrocarbons (PAHs) deposition inferred from a sediment core of an Andean lake in south central Chile. Sediments were carefully collected from one of the deepest section of the lake and sliced every 1 cm. The samples were analyzed for PAHs, 137 Cs, 210 Pb, organic carbon and grain-size. The stratigraphic chronology and the sedimentation rates were estimated using the sedimentary signature left by the 137 Cs and 210 Pb fallout as temporal markers. PAHs were quantified by HPLC-fluorescence detection (HPLC-Fluorescence). 15 priority EPA PAHs were analyzed in this study. Based on these results, PAH deposition over the last 50 years was estimated (a period characterized by an important intervention in the area). PAH concentration ranged from 226 to 620 ng g -1 d.w. The highest concentrations of PAHs were found in the core's bottom. The PAH profile is dominated by the presence of perylene indicating a natural source of PAH. In addition, two clear PAH deposition periods could be determined: the most recent with two-four rings PAHs, the older one with five-seven rings predomination. Determined fluxes where 71 to 972 μg m -2 year -1 , dominated by perylene deposition. PAH levels and fluxes are lower compared to the levels found in sediments from remote lakes in Europe and North America. It is concluded that the main source of PAHs into the Laja Lake sediments are of natural origin

  19. Uranium concentrations in stream waters and sediments from selected sites in the eastern Seward Peninsula, Koyukuk, and Charley River areas, and across South-Central Alaska

    International Nuclear Information System (INIS)

    Sharp, R.R. Jr.; Hill, D.E.

    1978-04-01

    During the summer of 1975, a 6-week reconnaissance was conducted in widespread areas of Alaska as part of the National Uranium Resource Evaluation (NURE) program; Water, stream sediment, and bedrock samples were taken from the eastern Seward Peninsula, from north of Koyukuk River, from the Charley River area, and from across south central Alaska. This report contains the LASL uranium determinations resulting from fluorometric analysis of the water samples and delayed-neutron counting of the stream sediment samples. Results of total uranium for 611 water and 641 sediment samples, from 691 stream locations, are presented. Overlays showing the numbered sample locations and graphically portraying the concentrations of uranium in water and stream sediment samples, at 1:250,000 scale for use with existing National Topographic Map Series (NTMS) sheets and published geologic maps, are provided as plates. The main purposes of this work are to make the uranium data available to the public in the standard computer format used in the NURE Hydrogeochemical and Stream Sediment Reconnaissance (i.e., with a DOE sample number giving the latitude and longitude of each sample location) and to provide uranium concentration overlays at the standard scale of 1:250,000 adopted by the DOE for the NURE program. It also allows a plausible explanation of differences between the uranium values for sediment as determined by acid dissolution/extraction/fluorometry and by delayed-neutron counting that were noted in the earlier report

  20. Disparity between state fish consumption advisory systems for Methylmercury and US Environmental Protection Agency recommendations: a case study of the South Central United States

    Science.gov (United States)

    Adams, Kimberly; Drenner, Ray W.; Chumchal, Matthew M.; Donato, David I.

    2015-01-01

    Fish consumption advisories are used to inform citizens in the United States about noncommercial game fish with hazardous levels of methylmercury (MeHg). The US Environmental Protection Agency (USEPA) suggests issuing a fish consumption advisory when concentrations of MeHg in fish exceed a human health screening value of 300 ng/g. However, states have authority to develop their own systems for issuing fish consumption advisories for MeHg. Five states in the south central United States (Arkansas, Louisiana, Mississippi, Oklahoma, and Texas) issue advisories for the general human population when concentrations of MeHg exceed 700 ng/g to 1000 ng/g. The objective of the present study was to estimate the increase in fish consumption advisories that would occur if these states followed USEPA recommendations. The authors used the National Descriptive Model of Mercury in Fish to estimate the mercury concentrations in 5 size categories of largemouth bass–equivalent fish at 766 lentic and lotic sites within the 5 states. The authors found that states in this region have not issued site-specific fish consumption advisories for most of the water bodies that would have such advisories if USEPA recommendations were followed. One outcome of the present study may be to stimulate discussion between scientists and policy makers at the federal and state levels about appropriate screening values to protect the public from the health hazards of consuming MeHg-contaminated game fish.

  1. Effects of projected climate (2011–50) on karst hydrology and species vulnerability—Edwards aquifer, south-central Texas, and Madison aquifer, western South Dakota

    Science.gov (United States)

    Mahler, Barbara J.; Stamm, John F.; Poteet, Mary F.; Symstad, Amy J.; Musgrove, MaryLynn; Long, Andrew J.; Norton, Parker A.

    2015-12-22

    Karst aquifers—formed by the dissolution of soluble rocks such as limestone—are critical groundwater resources in North America, and karst springs, caves, and streams provide habitat for unique flora and fauna. Springflow and groundwater levels in karst terrane can change greatly over short time scales, and therefore are likely to respond rapidly to climate change. How might the biological communities and ecosystems associated with karst respond to climate change and accompanying changes in groundwater levels and springflow? Sites in two central U.S. regions—the Balcones Escarpment of south-central Texas and the Black Hills of western South Dakota (fig. 1)—were selected to study climate change and its potential effects on the local karst hydrology and ecosystem. The ecosystems associated with the Edwards aquifer (Balcones Escarpment region) and Madison aquifer (Black Hills region) support federally listed endangered and threatened species and numerous State-listed species of concern, including amphibians, birds, insects, and plants. Full results are provided in Stamm and others (2014), and are summarized in this fact sheet.

  2. Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran

    KAUST Repository

    Landgraf, A.

    2013-09-01

    The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a “simple” to a “composite” state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex.

  3. Nocturnal arboreality in snakes in the swamplands of the Atchafalaya Basin of south-central Louisiana and Big Thicket National Preserve of Southeast Texas

    Science.gov (United States)

    Glorioso, Brad M.; Waddle, J. Hardin

    2017-01-01

    The southeastern United States is home to a diverse assemblage of snakes, but only one species, the Rough Greensnake (Opheodrys aestivus), is considered specialized for a predominantly arboreal lifestyle. Other species, such as Ratsnakes (genus Pantherophis) and Ribbonsnakes/Gartersnakes (genus Thamnophis), are widely known to climb into vegetation and trees. Some explanations given for snake climbing behavior are foraging, thermoregulation, predator avoidance, and response to flood. Reports of arboreality in snake species typically not associated with life in the trees (such as terrestrial, aquatic, and even fossorial species) usually come from single observations, with no knowledge of prevalence of the behavior. Here, we report on arboreality of snake species detected during 8 years of night surveys in the Atchafalaya Basin of south-central Louisiana and 5+ years of night surveys in Big Thicket National Preserve in southeast Texas. We recorded a total of 1,088 detections of 19 snake species between the two study areas, with 348 detections above ground level (32%). The Rough Greensnake and Western Ribbonsnake (Thamnophis proximus) accounted for nearly 75% of total arboreal detections among the two study areas. However, with one exception, all snake species detected more than once between both study areas had at least one arboreal detection. These observations demonstrate that snakes with widely varying natural histories may be found in the trees at night, and for some species, this behavior may be more common than previously believed.

  4. Discharge, suspended sediment, and salinity in the Gulf Intracoastal Waterway and adjacent surface waters in South-Central Louisiana, 1997–2008

    Science.gov (United States)

    Swarzenski, Christopher M.; Perrien, Scott M.

    2015-10-19

    Discharge, suspended sediment, and salinity data collected between 1997 and 2008 indicate that the Gulf Intracoastal Waterway (GIWW) is an important distributary of river water and suspended sediments to coastal wetlands in south-central coastal Louisiana. Following natural hydraulic gradients, the GIWW passively distributes freshwater and suspended sediments from the Atchafalaya River to areas at least 30 to 50 miles west and east, respectively, of Morgan City. The magnitude and reach of the discharge in the GIWW increase as stage of the Wax Lake Outlet at Calumet and Lower Atchafalaya River (LAR) at Morgan City increase. The magnitude and duration of discharge vary from year to year depending on the flow regime of the Atchafalaya River. Annual discharge of water in the GIWW was greater during years when stage of the LAR remained anomalously high throughout the year, compared with average and peak flood years. During years when Atchafalaya River flow is low, Bayou Boeuf, a waterway draining the Verret subbasin, becomes a major source of water maintaining the eastward flow in the GIWW. The GIWW is the only means of getting river water to some parts of coastal Louisiana.

  5. Contrasting Eutrophication Risks and Countermeasures in Different Water Bodies: Assessments to Support Targeted Watershed Management.

    Science.gov (United States)

    Li, Tong; Chu, Chunli; Zhang, Yinan; Ju, Meiting; Wang, Yuqiu

    2017-06-29

    Eutrophication is a major problem in China. To combat this issue, the country needs to establish water quality targets, monitoring systems, and intelligent watershed management. This study explores a new watershed management method. Water quality is first assessed using a single factor index method. Then, changes in total nitrogen/total phosphorus (TN/TP) are analyzed to determine the limiting factor. Next, the study compares the eutrophication status of two water function districts, using a comprehensive nutritional state index method and geographic information system (GIS) visualization. Finally, nutrient sources are qualitatively analyzed. Two functional water areas in Tianjin, China were selected and analyzed: Qilihai National Wetland Nature Reserve and Yuqiao Reservoir. The reservoir is a drinking water source. Results indicate that total nitrogen (TN) and total phosphorus (TP) pollution are the main factors driving eutrophication in the Qilihai Wetland and Yuqiao Reservoir. Phosphorus was the limiting factor in the Yuqiao Reservoir; nitrogen was the limiting factor in the Qilihai Wetland. Pollution in Qilihai Wetland is more serious than in Yuqiao Reservoir. The study found that external sources are the main source of pollution. These two functional water areas are vital for Tianjin; as such, the study proposes targeted management measures.

  6. Biogeochemical mass balances in a turbid tropical reservoir. Field data and modelling approach

    Science.gov (United States)

    Phuong Doan, Thuy Kim; Némery, Julien; Gratiot, Nicolas; Schmid, Martin

    2014-05-01

    The turbid tropical Cointzio reservoir, located in the Trans Mexican Volcanic Belt (TMVB), behaves as a warm monomictic water body (area = 6 km2, capacity 66 Mm3, residence time ~ 1 year). It is strategic for the drinking water supply of the city of Morelia, capital of the state of Michoacán, and for downstream irrigation during the dry season. This reservoir is a perfect example of a human-impacted system since its watershed is mainly composed of degraded volcanic soils and is subjected to high erosion processes and agricultural loss. The reservoir is threatened by sediment accumulation and nutrients originating from untreated waters in the upstream watershed. The high content of very fine clay particles and the lack of water treatment plants lead to serious episodes of eutrophication (up to 70 μg chl. a L-1), high levels of turbidity (Secchi depth water vertical profiles, reservoir inflow and outflow) we determined suspended sediment (SS), carbon (C), nitrogen (N) and phosphorus (P) mass balances. Watershed SS yields were estimated at 35 t km2 y-1 of which 89-92 % were trapped in the Cointzio reservoir. As a consequence the reservoir has already lost 25 % of its initial storage capacity since its construction in 1940. Nutrient mass balances showed that 50 % and 46 % of incoming P and N were retained by sedimentation, and mainly eliminated through denitrification respectively. Removal of C by 30 % was also observed both by sedimentation and through gas emission. To complete field data analyses we examined the ability of vertical one dimensional (1DV) numerical models (Aquasim biogeochemical model coupled with k-ɛ mixing model) to reproduce the main biogeochemical cycles in the Cointzio reservoir. The model can describe all the mineralization processes both in the water column and in the sediment. The values of the entire mass balance of nutrients and of the mineralization rates (denitrification and aerobic benthic mineralization) calculated from the model

  7. APPLICATION OF INTEGRATED RESERVOIR MANAGEMENT AND RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jack Bergeron; Tom Blasingame; Louis Doublet; Mohan Kelkar; George Freeman; Jeff Callard; David Moore; David Davies; Richard Vessell; Brian Pregger; Bill Dixon; Bryce Bezant

    2000-03-01

    Reservoir performance and characterization are vital parameters during the development phase of a project. Infill drilling of wells on a uniform spacing, without regard to characterization does not optimize development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, especially carbonate reservoirs. These reservoirs are typically characterized by: (1) large, discontinuous pay intervals; (2) vertical and lateral changes in reservoir properties; (3) low reservoir energy; (4) high residual oil saturation; and (5) low recovery efficiency. The operational problems they encounter in these types of reservoirs include: (1) poor or inadequate completions and stimulations; (2) early water breakthrough; (3) poor reservoir sweep efficiency in contacting oil throughout the reservoir as well as in the nearby well regions; (4) channeling of injected fluids due to preferential fracturing caused by excessive injection rates; and (5) limited data availability and poor data quality. Infill drilling operations only need target areas of the reservoir which will be economically successful. If the most productive areas of a reservoir can be accurately identified by combining the results of geological, petrophysical, reservoir performance, and pressure transient analyses, then this ''integrated'' approach can be used to optimize reservoir performance during secondary and tertiary recovery operations without resorting to ''blanket'' infill drilling methods. New and emerging technologies such as geostatistical modeling, rock typing, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can then be used to develop a 3-D simulation model for prediction of infill locations. The application of reservoir surveillance techniques to identify additional reservoir ''pay'' zones

  8. Watershed and longitudinal monitoring events

    Science.gov (United States)

    Harold Harbert; Steven Blackburn

    2016-01-01

    Georgia Adopt-A-Stream partners annually with many organizations, universities and watershed groups to conduct sampling events with volunteers at a watershed level. These monitoring events range from one-day snapshots to week-long paddle trips. One-day sampling events, also called “Blitzs,” River Adventures and River Rendezvous, generally target 20-50 sites within a...

  9. Understanding the Role of Reservoir Size on Probable Maximum Precipitation

    Science.gov (United States)

    Woldemichael, A. T.; Hossain, F.

    2011-12-01

    This study addresses the question 'Does surface area of an artificial reservoir matter in the estimation of probable maximum precipitation (PMP) for an impounded basin?' The motivation of the study was based on the notion that the stationarity assumption that is implicit in the PMP for dam design can be undermined in the post-dam era due to an enhancement of extreme precipitation patterns by an artificial reservoir. In addition, the study lays the foundation for use of regional atmospheric models as one way to perform life cycle assessment for planned or existing dams to formulate best management practices. The American River Watershed (ARW) with the Folsom dam at the confluence of the American River was selected as the study region and the Dec-Jan 1996-97 storm event was selected for the study period. The numerical atmospheric model used for the study was the Regional Atmospheric Modeling System (RAMS). First, the numerical modeling system, RAMS, was calibrated and validated with selected station and spatially interpolated precipitation data. Best combinations of parameterization schemes in RAMS were accordingly selected. Second, to mimic the standard method of PMP estimation by moisture maximization technique, relative humidity terms in the model were raised to 100% from ground up to the 500mb level. The obtained model-based maximum 72-hr precipitation values were named extreme precipitation (EP) as a distinction from the PMPs obtained by the standard methods. Third, six hypothetical reservoir size scenarios ranging from no-dam (all-dry) to the reservoir submerging half of basin were established to test the influence of reservoir size variation on EP. For the case of the ARW, our study clearly demonstrated that the assumption of stationarity that is implicit the traditional estimation of PMP can be rendered invalid to a large part due to the very presence of the artificial reservoir. Cloud tracking procedures performed on the basin also give indication of the

  10. Trapping Efficiency of Fine Sediments in Reservoir Lake in Fukushima Rivers as Revealed by Radiocaesium attached in Suspended Sediment

    Science.gov (United States)

    Taniguchi, K.; Onda, Y.; Kuramoto, T.; Smith, H.; Blake, W.; Onuma, S.; Sato, T.; Arai, H.; Blake, W.

    2017-12-01

    Radiocaesium released from Fukushima Daiichi Nuclear Power Plant were widely distributed in the surrounded area. The radiocaesium deposited inland area were adsorbed to fine particles of the surface soils such as silt and clay particles. The contaminated particles were eroded by rainfall events, and then transported through river systems. The purpose of this research is to investigate the impact of existence of large reservoirs on the riverine transport of fine sediments by using the 137Cs as a kind of tracer. At 30 monitoring sites located in 9 river systems in the area affected by the accident, suspended sediments (SS) ware collected by time-integrated SS samplers. The particulate radiocaesium activity concentration was measured by germanium detector. The water discharge and SS flux each site were calculated by the water level and turbidity data every 10 minutes obtained by monitoring. The 137Cs flux was calculated by multiplying the activity concentration and the SS flux. The Cs-137 flux normalized by the water discharge and initial deposition of 137Cs in the watershed (L/QD) showed a correlation with the coverages of land use types in the watershed in the case of monitoring sites where there was no large reservoir in the watershed. However, at the sites that have large reservoir in the watershed, the value of L/QD were 6.5 -21 % of the values estimated by the coverage of land use types. This result implies that approximately more than 80 % of the fine SS is trapped by the reservoirs.

  11. Analysis, Evaluation and Measures to Reduce Environmental Risk within Watershed Areas of the Eastern Zauralye District Lakes

    Science.gov (United States)

    Rasskasova, N. S.; Bobylev, A. V.; Malaev, A. V.

    2017-11-01

    The authors have performed an analysis for the use of watershed areas of the lakes of the Eastern Zauralye district (the territory to the east of Ural) for national economic purposes. The analysis gave a possibility to assess the impact of watersheds depending on the applied technologies on the dump of various runoff into the reservoir waters. The watershed areas of all lakes have been found to be actively used as pastures, farmland and recreational resources. Some of the main sources of solid and liquid industrial waste are cattle farms and agricultural land using outdated equipment and technologies. The study of 26 km of the watershed line areas showed that pollutants (household garbage, fuels and lubricants) and organic substances (phosphorus and nitrogen) got into the waters of the reservoirs. The maximum runoff of solid and liquid waste into the waters of the lakes happens in summer which leads to increased concentrations of organic substances, an increase in productivity of alga and higher aquatic flora determining the degree of eutrophication and trophy in the reservoirs. The average annual trophic status of TSI lakes of the Eastern Zauralye district is 56 which corresponds to the typical phase of eutrophy. The reduced transparency of lakes is also the evidence of an increase in biological productivity of reservoirs, their eutrophication and, as a result, the water quality deterioration. The intensive eutrophication of reservoirs, in its turn, most significantly affects the concentration of the ammonium form of nitrogen, total phosphorus and total nitrogen, increase in pH and deterioration of oxygen condition. The authors have developed various activities to reduce a technogenic risk in the watershed areas of the lakes in the Eastern Zauralye district which can be applied to other areas using the analogy method.

  12. Water quality assessment of fifth-order tributaries of the reservoir at the Marechal Mascarenhas de Morais Hydroelectric Power Station in the Rio Grande watershed (State of Minas Gerais, Brazil Avaliação da qualidade da água dos afluentes de quinta ordem do reservatório da Usina Hidrelétrica de Marechal Mascarenhas de Morais na bacia hidrográfica do médio rio Grande (Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    Douglas de Pádua Andrade

    2012-09-01

    Full Text Available Aim: This study assessed the water quality from the springs and river mouths of the fifth-order tributaries which compose the reservoir of Marechal Mascarenhas de Morais HPS in the middle Rio Grande watershed, Minas Gerais, Brazil. Methods: It has been studied 14 tributaries distributed in the reservoir, two points for tributary - spring and river mouth. Eighteen limnological variables added to the Rapid Assessment Protocol and Trophic Level Index were evaluated. The benthic macroinvertebrates had been collected by the use of a granulometric sieve and a Petersen-type sampler. Results: The cluster analysis of limnological data revealed the existence of two tributary groups. Group I consisted of eutrophic tributaries degraded by human activities, while group II exhibited good water quality and well-preserved environments. Group I was divided into two subgroups, Ia tributaries were characterized by being altered by human activities, while the Ib subgroup was composed of highly impacted tributaries. By ordering the PCA, it can be observed spatial segregation of groups, where the most polluted tributaries were separated from those which are better preserved. A total of 8,987 individuals belonging to 36 families of macroinvertebrates were identified. The family Chironomidae was the most abundant. There was no significant difference in total abundance and the richness of macroinvertebrates taxa inhabiting springs, by those who inhabiting the river mouths. Conclusions: It was noticed that most of the tributaries which supply and composes the reservoir are already degraded and have low quality water. It is observed that the human presence drastically affected water quality and faunal composition of tributaries. Thus, it is necessary a complementary study of the tributaries in working with issues related to reservoirs, as these components have direct influence on the water quality and composition of these lentic environments.Objetivos: O trabalho avaliou

  13. Estimating hydrologic budgets for six Persian Gulf watersheds, Iran

    Science.gov (United States)

    Hosseini, Majid; Ghafouri, Mohammad; Tabatabaei, MahmoudReza; Goodarzi, Masoud; Mokarian, Zeinab

    2017-10-01

    Estimation of the major components of the hydrologic budget is important for determining the impacts on the water supply and quality of either planned or proposed land management projects, vegetative changes, groundwater withdrawals, and reservoir management practices and plans. As acquisition of field data is costly and time consuming, models have been created to test various land use practices and their concomitant effects on the hydrologic budget of watersheds. To simulate such management scenarios realistically, a model should be able to simulate the individual components of the hydrologic budget. The main objective of this study is to perform the SWAT2012 model for estimation of hydrological budget in six subbasin of Persian Gulf watershed; Golgol, Baghan, Marghab Shekastian, Tangebirim and Daragah, which are located in south and south west of Iran during 1991-2009. In order to evaluate the performance of the model, hydrological data, soil map, land use map and digital elevation model (DEM) are obtained and prepared for each catchment to run the model. SWAT-CUP with SUFI2 program was used for simulation, uncertainty and validation with 95 Percent Prediction Uncertainty. Coefficient of determination ( R 2) and Nash-Sutcliffe coefficient (NS) were used for evaluation of the model simulation results. Comparison of measured and predicted values demonstrated that each component of the model gave reasonable output and that the interaction among components was realistic. The study has produced a technique with reliable capability for annual and monthly water budget components in Persian Gulf watershed.

  14. Size distribution of planktonic autotrophy and microheterotrophy in DeGray Reservoir, Arkansas

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, B.L.; Groeger, A.W.

    1983-01-01

    Naturally occurring assemblages of phytoplankton and bacterioplankton were radiolabelled with sodium /sup 14/C-bicarbonate and sodium /sup 3/H-acetate and size fractionated to determine the size structure of planktonic autotrophy and microheterotrophy in DeGray Reservoir, an oligotrophic impoundment of the Caddo River in south-central Arkansas. Size distributions of autotrophy and microheterotrophy were remarkably uniform seasonally, vertically within the water column, and along the longitudinal axis of the reservoir despite significant changes in environmental conditions. Planktonic autotrophy was dominated by small algal cells with usually >50% of the photosynthetic carbon uptake accounted for by organisms <8.0 ..mu..m. Microheterotrophic activity in the 0.2- to 1.0-..mu..m size fraction, presumably associated with free-living bacterioplankton not attached to suspended particles, usually accounted for >75% of the planktonic microheterotrophy. Longitudinal patterns in autotrophic and microheterotrophic activities associated with >3-..mu..m and >1-..mu..m size fractions, respectively, suggest an uplake to downlake shift from riverine to lacustrine environmental influences within the reservoir. 83 references, 7 figures.

  15. Budgeting suspended sediment fluxes in tropical monsoonal watersheds with limited data: the Lake Tana basin

    Directory of Open Access Journals (Sweden)

    Zimale Fasikaw A.

    2018-03-01

    Full Text Available Soil erosion decreases soil fertility of the uplands and causes siltation of lakes and reservoirs; the lakes and reservoirs in tropical monsoonal African highlands are especially affected by sedimentation. Efforts in reducing loads by designing management practices are hampered by lack of quantitative data on the relationship of erosion in the watersheds and sediment accumulation on flood plains, lakes and reservoirs. The objective of this study is to develop a prototype quantitative method for estimating sediment budget for tropical monsoon lakes with limited observational data. Four watersheds in the Lake Tana basin were selected for this study. The Parameter Efficient Distributed (PED model that has shown to perform well in the Ethiopian highlands is used to overcome the data limitations and recreate the missing sediment fluxes. PED model parameters are calibrated using daily discharge data and the occasionally collected sediment concentration when establishing the sediment rating curves for the major rivers. The calibrated model parameters are then used to predict the sediment budget for the 1994-2009 period. Sediment retained in the lake is determined from two bathymetric surveys taken 20 years apart whereas the sediment leaving the lake is calculated based on measured discharge and observed sediment concentrations. Results show that annually on average 34 t/ha/year of sediment is removed from the gauged part of the Lake Tana watersheds. Depending on the up-scaling method from the gauged to the ungauged part, 21 to 32 t/ha/year (equivalent to 24-38 Mt/year is transported from the upland watersheds of which 46% to 65% is retained in the flood plains and 93% to 96% is trapped on the flood plains and in the lake. Thus, only 4-7% of all sediment produced in the watersheds leaves the Lake Tana Basin.

  16. Impacts of channel deposition on the risk of flooding in a watershed

    Science.gov (United States)

    Ting-Yue, Hong; Chia-Ling, Chang

    2017-04-01

    Taiwan is located in East Asian where is always hit by typhoons. Typhoons usually bring huge amounts of rainfall and result in the problems of channel deposition. Deposition influences the functions of channel and increases the risk of flooding. The Luliao Reservoir Watershed is the case area in this study. It is the major water source for agricultural activity and domestic use. The objective of this study is to assess the possible impacts of channel deposition on the watershed environment. This study applies the Storm Water Management Model (SWMM) to predict the hydrologic responses and evaluate the risk of flooding. The results show that the decrease of cross section induced by deposition in a channel may increase the risk of flooding and impact the safety of watershed environment. Therefore, canal desilting is important in channel regulation. The discussion and analysis can be useful references for channel regulation.

  17. SWAT Model Prediction of Phosphorus Loading in a South Carolina Karst Watershed with a Downstream Embayment

    Science.gov (United States)

    Devendra M. Amatya; Manoj K. Jha; Thomas M. Williams; Amy E. Edwards; Daniel R.. Hitchcock

    2013-01-01

    The SWAT model was used to predict total phosphorus (TP) loadings for a 1555-ha karst watershed—Chapel Branch Creek (CBC)—which drains to a lake via a reservoir-like embayment (R-E). The model was first tested for monthly streamflow predictions from tributaries draining three potential source areas as well as the downstream R-E, followed by TP loadings using data...

  18. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  19. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yutian Luo

    2017-01-01

    Full Text Available This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results.

  20. Structural and Conservation Effort Alternatives to Extending Jatigede Reservoir Service Lifetime by Limiting Sedimentation

    Science.gov (United States)

    Rohmat, F. I.; Hadihardaja, I. K.; Rohmat, D.

    2013-12-01

    Jatigede Reservoir, which is being constructed in West Java province, Indonesia, is planned to begin operation in late 2013. It is designed to provide 90,000 ha of paddy field irrigation, 100 MW power generation, and flood control. However, previous studies indicate that the reservoir will only have a service life of 7 to 30 years, rather than its 100-year design service life. One reason is the high rate of sedimentation, which is predicted to reach more than 8 million tons per year because of changes in land use in the watershed. This condition is aggravated by the removal of the flushing gate on the bottom of the dam. This study examines alternatives to extend the service life of Jatigede Reservoir, including a structural solution (extending and raising the irrigation inlet to increase the dead storage), watershed conservation, and a combination of these alternatives. The structural effort may extend the reservoir's service life by 10 to 20 years, but with considerable effect on increasing flooding and drought risk by reduced live storage. Structural options need to be combined with conservation options in order to extend the service life of Jatigede Reservoir to the desired range.

  1. Small reservoir effects on headwater water quality in the rural-urban fringe, Georgia Piedmont, USA

    Directory of Open Access Journals (Sweden)

    Dr.. Amber R. Ignatius, Geographer

    2016-12-01

    Full Text Available Small reservoirs are prevalent landscape features that affect the physical, chemical, and biological characteristics of headwater streams. Tens of thousands of small reservoirs, often less than a hectare in size, were constructed over the past century within the United States. While remote-sensing and geographic-mapping technologies assist in identifying and quantifying these features, their localized influence on water quality is uncertain. We report a year-long physicochemical study of nine small reservoirs (0.15–2.17 ha within the Oconee and Broad River Watersheds in the Georgia Piedmont. Study sites were selected along an urban-rural gradient with differing amounts of agricultural, forested, and developed land covers. Sites were sampled monthly for discharge and inflow/outflow water quality parameters (temperature, specific conductance, pH, dissolved oxygen, turbidity, alkalinity, total phosphorus, total nitrogen, nitrate, ammonium. While the proportion of developed land cover within watersheds had positive correlations with reservoir specific conductivity values, agricultural and forested land covers showed correlations (positive and negative, respectively with reservoir alkalinity, total nitrogen, nitrate, and specific conductivity. The majority of outflow temperatures were warmer than inflows for all land uses throughout the year, especially in the summer. Outflows had lower nitrate concentrations, but higher ammonium. The type of outflow structure was also influential; top-release dams showed higher dissolved oxygen and pH than bottom-release dams. Water quality effects were still evident 250 m below the dam, albeit reduced.

  2. Occurrence of methane in groundwater of south-central New York State, 2012-systematic evaluation of a glaciated region by hydrogeologic setting

    Science.gov (United States)

    Heisig, Paul M.; Scott, Tia-Marie

    2013-01-01

    A survey of methane in groundwater was undertaken to document methane occurrence on the basis hydrogeologic setting within a glaciated 1,810-square-mile area of south-central New York along the Pennsylvania border. Sixty-six wells were sampled during the summer of 2012. All wells were at least 1 mile from any known gas well (active, exploratory, or abandoned). Results indicate strong positive and negative associations between hydrogeologic settings and methane occurrence. The hydrogeologic setting classes are based on topographic position (valley and upland), confinement or non-confinement of groundwater by glacial deposits, well completion in fractured bedrock or sand and gravel, and hydrogeologic subcategories. Only domestic wells and similar purposed supply wells with well-construction and log information were selected for classification. Field water-quality characteristics (pH, specific conductance, dissolved oxygen, and temperature) were measured at each well, and samples were collected and analyzed for dissolved gases, including methane and short-chain hydrocarbons. Carbon and hydrogen isotopic ratios of methane were measured in 21 samples that had at least 0.3 milligram per liter (mg/L) of methane. Results of sampling indicate that occurrence of methane in groundwater of the region is common—greater than or equal to 0.001 mg/L in 78 percent of the groundwater samples. Concentrations of methane ranged over five orders of magnitude. Methane concentrations at which monitoring or mitigation are indicated (greater than or equal to 10 mg/L) were measured in 15 percent of the samples. Methane concentrations greater than 0.1 mg/L were associated with specific hydrogeologic settings. Wells completed in bedrock within valleys and under confined groundwater conditions were most closely associated with the highest methane concentrations. Fifty-seven percent of valley wells had greater than or equal to 0.1 mg/L of methane, whereas only 10 percent of upland wells

  3. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. I. - July of 2001; Asesoria especializada en seguridad radiologica al hospital central sur de alta especialidad, PEMEX I.- Julio de 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J

    2001-09-15

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  4. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. II.- August of 2001; Asesoria especializada en seguridad radiologica al hospital central sur de alta especialidad, PEMEX II.- Agosto de 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Rodriguez A, F.; Garcia A, J

    2001-12-15

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  5. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. IV. - October of 2001; Asesoria especializada en seguridad radiologica a la clinica al hospital central sur de alta especialidad, PEMEX. IV.- Octubre de 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Garcia A, J.; Rodriguez A, F

    2002-01-15

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  6. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. III.- September of 2001; Asesoria especializada en seguridad radiologica al hospital central sur de alta especialidad, PEMEX III.- Septiembre de 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Rodriguez A, F.; Garcia A, J

    2001-12-15

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Author)

  7. Specialized consultant in radiological safety to the south central hospital of high speciality, PEMEX. V. - November of 2001; Asesoria especializada en seguridad radiologica al hospital central sur de alta especialidad, PEMEX. V.- Noviembre de 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J.; Benitez S, J. A.; Garcia A, J.; Rodriguez A, F

    2002-01-15

    The south central hospital of high speciality, dependent of PEMEX, It request consultant of the ININ to be able to maintain their sanitary license for the use of X-ray equipment for the radiologic diagnostic.The proposal of the ININ was to be a program of technical attendance, schedule monthly to be able to solve the observations that are presented in the use of those equipment, and that the hospital can conserve its respective sanitary license.(Autho000.

  8. Nebela jiuhuensis nov. sp. (Amoebozoa; Arcellinida; Hyalospheniidae): A New Member of the Nebela saccifera - equicalceus - ansata Group Described from Sphagnum Peatlands in South-Central China.

    Science.gov (United States)

    Qin, Yangmin; Man, Baiying; Kosakyan, Anush; Lara, Enrique; Gu, Yansheng; Wang, Hongmei; Mitchell, Edward A D

    2016-09-01

    Hyalospheniids are among the most common and conspicuous testate amoebae in high-latitude peatlands and forest humus. These testate amoebae were widely studied as bioindicators and are increasingly used as models in microbial biogeography. However, data on their diversity and ecology are still very unevenly distributed geographically: notably, data are lacking for low-latitude peatlands. We describe here a new species, Nebela jiuhuensis, from peatlands near the Middle Yangtze River reach of south-central China with characteristic morphology. The test (shell) has hollow horn-like lateral extensions also found in N. saccifera, N. equicalceus (=N. hippocrepis), and N. ansata, three large species restricted mostly to Sphagnum peatlands of Eastern North America. Mitochondrial cytochrome oxidase (COI) data confirm that N. jiuhuensis is closely related to the morphologically very similar North American species N. saccifera and more distantly to N. ansata within the N. penardiana group. These species are all found in wet mosses growing in poor fens. Earlier reports of morphologically similar specimens found in South Korea peatlands suggest that N. jiuhuensis may be distributed in comparable peatlands in Eastern Asia (China and Korea). The discovery of such a conspicuous new species in Chinese peatlands suggests that many new testate amoebae species are yet to be discovered, including potential regional endemics. Furthermore, human activities (e.g., drainage, agriculture, and pollution) have reduced the known habitat of N. jiuhuensis, which can thus be considered as locally endangered. We, therefore, suggest that this very conspicuous micro-organism with a probably limited geographical distribution and specific habitat requirement should be considered as a flagship species for microbial biogeography as well as local environmental conservation and management. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  9. The role of E-W basement faults in the Mesozoic geodynamic evolution of the Gafsa and Chotts basins, south-central Tunisia

    Science.gov (United States)

    Amri, Dorra Tanfous; Dhahri, Ferid; Soussi, Mohamed; Gabtni, Hakim; Bédir, Mourad

    2017-10-01

    The Gafsa and Chotts intracratonic basins in south-central Tunisia are transitional zones between the Atlasic domain to the north and the Saharan platform to the south. The principal aim of this paper is to unravel the geodynamic evolution of these basins following an integrated approach including seismic, well log and gravity data. These data are used to highlight the tectonic control on the deposition of Jurassic and Lower Cretaceous series and to discuss the role of the main faults that controlled the basin architecture and Cretaceous-Tertiary inversion. The horizontal gravity gradient map of the study area highlights the pattern of discontinuities within the two basins and reveals the presence of deep E-W basement faults. Primary attention is given to the role played by the E-W faults system and that of the NW-SE Gafsa fault which was previously considered active since the Jurassic. Facies and thickness analyses based on new seismic interpretation and well data suggest that the E-W-oriented faults controlled the subsidence distribution especially during the Jurassic. The NW-SE faults seem to be key structures that controlled the basins paleogeography during Late Cretaceous-Cenozoic time. The upper Triassic evaporite bodies, which locally outline the main NW-SE Gafsa fault, are regarded as intrusive salt bodies rather than early diapiric extrusions as previously interpreted since they are rare and occurred only along main strike-slip faults. In addition, seismic lines show that Triassic rocks are deep and do not exhibit true diapiric features.

  10. Potential influence of the late Holocene climate on settled farming versus nomadic cattle herding in the Minusinsk Hollow, south-central Siberia

    International Nuclear Information System (INIS)

    Blyakharchuk, T A; Tchebakova, N M; Parfenova, E I; Soja, A J

    2014-01-01

    Prehistoric and early historic human cultures are known to be closely connected to and dependent on their natural environments. We test the hypothesis that climate change influenced the means of subsistence of ancient tribes and favored agricultural or cattle herding economic strategies. Our study area is the Khakass–Minusinsk Hollow, located in the foothills of the Sayan Mountains, south-central Siberia, which was, for a few millennia, a buffer zone for human migrations across the Great Eurasian Steppe. Three different methods (the Montane BioClimatic Model, MontBCliM; the biomization method; and the actualizm method) are employed to reconstruct vegetation taken from the fossil pollen of sediment cores in two mountain lakes at eleven time slices related to successive human cultures back to the mid-Holocene. MontBCliM model is used inversely to convert site paleo-vegetation into site paleo-climates. Climate-based regression models are developed and applied to reconstructed climates to evaluate possible pasture and grain crops for these time slices. Pollen-based reconstructions of the climate fluctuations uncovered several dry periods with steppe and forest-steppe and wetter periods with forests since 6000 BP. Grasslands increased by an order of magnitude during the dry periods and provided extensive open space suitable for pastoralism; however, both grain and pasture yields decreased during these dry periods. During wetter climates, both grain and pasture yields increased twofold and supported more fixed human settlements centered around farming and cattle herding. Thus, the dry periods favored pastoralist rather than farming activities. Conversely, tribes that practiced agriculture had some advantage in the wet periods. (papers)

  11. Differential Late Paleozoic active margin evolution in South-Central Chile (37°S-40°S) - the Lanalhue Fault Zone

    Science.gov (United States)

    Glodny, Johannes; Echtler, Helmut; Collao, Santiago; Ardiles, Mary; Burón, Pablo; Figueroa, Oscar

    2008-12-01

    The N-S oriented Coastal Cordillera of South Central Chile shows marked lithological contrasts along strike at ˜38°S. Here, the sinistral NW-SE-striking Lanalhue Fault Zone ( nomen novum) juxtaposes Permo-Carboniferous magmatic arc granitoids and associated, frontally accreted metasediments (Eastern Series) in the northeast with a Late Carboniferous to Triassic basal-accretionary forearc wedge complex (Western Series) in the southwest. The fault is interpreted as an initially ductile deformation zone with divergent character, located in the eastern flank of the basally growing, upwarping, and exhuming Western Series. It was later transformed and reactivated as a semiductile to brittle sinistral transform fault. Rb-Sr data and fluid inclusion studies of late-stage fault-related mineralizations revealed Early Permian ages between 280 and 270 Ma for fault activity, with subsequent minor erosion. Regionally, crystallization of arc intrusives and related metamorphism occurred between ˜306 and ˜286 Ma, preceded by early increments of convergence-related deformation. Basal Western Series accretion started at >290 Ma and lasted to ˜250 Ma. North of the Lanalhue fault, Late Paleozoic magmatic arc granitoids are nearly 100 km closer to the present day Andean trench than further south. We hypothesize that this marked difference in paleo-forearc width is due to an Early Permian period of subduction erosion north of 38°S, contrasting with ongoing accretion further south, which kinematically triggered the evolution of the Lanalhue Fault Zone. Permo-Triassic margin segmentation was due to differential forearc accretion and denudation characteristics, and is now expressed in contrasting lithologies and metamorphic signatures in todays Andean forearc region north and south of the Lanalhue Fault Zone.

  12. A deglacial and Holocene record of climate variability in south-central Alaska from stable oxygen isotopes and plant macrofossils in peat

    Science.gov (United States)

    Jones, Miriam C.; Wooller, Matthew J.; Peteet, Dorothy M.

    2014-01-01

    We used stable oxygen isotopes derived from bulk peat (δ18OTOM), in conjunction with plant macrofossils and previously published carbon accumulation records, in a ∼14,500 cal yr BP peat core (HT Fen) from the Kenai lowlands in south-central Alaska to reconstruct the climate history of the area. We find that patterns are broadly consistent with those from lacustrine records across the region, and agree with the interpretation that major shifts in δ18OTOM values indicate changes in strength and position of the Aleutian Low (AL), a semi-permanent low-pressure cell that delivers winter moisture to the region. We find decreased strength or a more westerly position of the AL (relatively higher δ18OTOM values) during the Bølling-Allerød, Holocene Thermal Maximum (HTM), and late Holocene, which also correspond to warmer climate regimes. These intervals coincide with greater peat preservation and enhanced carbon (C) accumulation rates at the HT Fen and with peatland expansion across Alaska. The HTM in particular may have experienced greater summer precipitation as a result of an enhanced Pacific subtropical high, a pattern consistent with modern δ18O values for summer precipitation. The combined warm summer temperatures and greater summer precipitation helped promote the observed rapid peat accumulation. A strengthened AL (relatively lower δ18OTOM values) is most evident during the Younger Dryas, Neoglaciation, and the Little Ice Age, consistent with lower peat preservation and C accumulation at the HT Fen, suggesting less precipitation reaches the leeward side of the Kenai Mountains during periods of enhanced AL strength. The peatlands on the Kenai Peninsula thrive when the AL is weak and the contribution of summer precipitation is higher, highlighting the importance of precipitation seasonality in promoting peat accumulation. This study demonstrates that δ18OTOM values in peat can be applied toward understand large-scale shifts in atmospheric circulation

  13. Discard composition associated with the deep water rose shrimp fisheries (Parapenaeus longirostris, Lucas 1846 in the south-central Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. MILISENDA

    2017-02-01

    Full Text Available Discarding in fisheries is believed to be a waste of natural resources, as it is the part of the total catch brought on board but then returned to the sea dead or alive for any reason. This study aims to advance knowledge of the discards associated with the deep water rose shrimp fisheries in the south-central Mediterranean Sea. We address this issue by examining the data collected within the module of commercial catch monitoring (Campbiol of European data collection framework (DCF between January 2009 and December 2013. Multivariate data analysis and the generalized additive model (GAMs were used to assess the spatio-temporal composition of the discard and factors influencing its distribution. Overall, discard represented 32.9±15.4% of the total catch. Multiple analysis of variance highlighted the significant effect on discard assemblage only for the factor of depth (p-value <0.05. In general, bony fish were the most discarded organisms (23.5±14.4%. Cartilaginous fish, crustaceans and other invertebrates represented approximately 13% of the total catch. The fraction of discard in the catch presented significant variation regarding the years, depth and fishing ground. Our results showed that most of the discards in the deep water rose shrimp (DPS fisheries are due to species that have a minimum legal size (Hake, DPS, Trachurus spp., and are consequently subjected to the discard ban (art. 15 of the reg. EU 1380/2013. To avoid the landing of discards, specific measures aimed to minimize the unwanted catches of undersized species should be implemented.

  14. P12.01 Epidemiology in spinal tumors treated surgically at the South Central Hospital of High Specialty from PEMEX in Mexico

    Science.gov (United States)

    Hernandez Resendiz, R.; Cordoba Mosqueda, M.; Guerra Mora, J.; Loya Aguilar, I.; Garcia Gonzalez, U.

    2016-01-01

    Abstract Introduction: The spinal tumors are rare neoplasms, they can be primary or metastatic; in the literature they are divided in extradural and intradural, extramedullary and intramedullary, from which extradural tumors are the most frequent and are usually metastatic, the intramedullary are generally gliomas. From the primary tumors up to 78% are benign and 22% malign, the histological stripe and the involvement to the spinal compartments are of great importance for the results and the treatment which is mainly surgical, individualized and meticulously planned with the support of technological resources such as the electrophysiological monitoring during the surgery. Methods and Materials: Observational study with a range of patients from March 1999- March 2016 to whom surgical resection of the spinal tumor was performed and reported on the Electronic Files of the South Central Hospital of High Specialty PEMEX. A Statistical analysis is made with the SPSS Statistic of disease of the Institution program. Results: 23 patients with spinal tumor surgical resection were found. The median age was 53 ± 10 years. The most common clinical manifestation was radiculopathy (65%). The Karnofsky scale was used for initial evaluation where a 43% of patients had a 90 score at the moment of the diagnosis, while 65% had an ECOG 1. The most frequent tumor was the Spinal Shwannoma (39%), followed in prevalence by the Condroid Cordoma (17%), where the intradural extramedullary location was the most prevalent (78%). The medium rate of survival after the surgical procedure was from 11 months. Conclusions: Our cases and the international statistics coincide. Radiculopathy as high prevalence initial manifestation conceals us to dismiss in the sixth decade of life any possibility for spinal tumor presentation. Most of spinal tumor patients do not have any clinical deterioration in their basal state, which indicates that performing a successful surgical procedure and the right

  15. Seismic imaging of the southern California plate-boundary around the South-Central Transverse Ranges using double-difference tomography

    Science.gov (United States)

    Share, P. E.; Ben-Zion, Y.; Thurber, C. H.; Zhang, H.; Guo, H.

    2017-12-01

    We derive P and S seismic velocities within and around the South-Central Transverse Ranges section of the San Andreas Fault (SAF), using a new double-difference tomography algorithm incorporating both event-pair and station-pair differential times. The event-pair data can determine high-resolution relative earthquake locations and resolve fine-scale structure in seismogenic zones, whereas station-pair data allow for better absolute locations and higher resolution of structure near the surface where stations are most dense. The tomographic results are based on arrival times of P and S waves generated by 17,753 M>1 local events from 1/1/2010 to 6/30/2015 recorded by 259 stations within a 222 km x 164 km region. The resulting P and S velocity models include low velocities along major fault segments and across-fault velocity contrasts. For example, at depths 50 km parallel to the SAF around Coachella Valley but offset to the NE by 13 km. This is interpreted to mark a dipping section of the SAF that separates granites at depth in the SW from gneisses and schists in the NE. Analysis of fault zone head waves propagating along these sections of the SAF and SJFZ show that major bimaterial interfaces are associated with the observed velocity contrasts. Additional features within the models include elongated low velocity anomalies extending from the SJFZ trifurcation area, which itself has associated low velocity at great depth (>14 km), to the Elsinore Fault in the SW. Moreover, a deep (>13 km) velocity contrast appears beneath the SBB with an east-west strike oblique to both the northern SJFZ and SAF traces. The latter is potentially related to the ancestral Banning Fault, which dips to the north, separating low velocity Pelona schist in the north from high velocity granites in the south.

  16. Seasonal mercury concentrations and δ15N and δ13C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile

    International Nuclear Information System (INIS)

    Díaz-Jaramillo, Mauricio; Muñoz, Claudia; Rudolph, Ignacio; Servos, Mark; Barra, Ricardo

    2013-01-01

    The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes (δ 15 N and δ 13 C). Mercury concentrations in Lenga sediments ranged from 0.4 ± 0.1 to 13 ± 3 mg/kg, while those in Tubul sediments ranged from 0.02 ± 0.01 to 0.07 ± 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p 0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of δ 13 C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources. -- Highlights: ► Hg in sediments and biota from Lenga Estuary were elevated compared to nearby estuary. ► Invertebrates showed interspecific and seasonal differences in terms of organic Hg %. ► Total Hg levels in the ragworm best reflect Hg sediment gradient in Lenga Estuary. ► Interspecific variation in δ 13 C signatures indicated different feeding modes. ► Organic forms of Hg in invertebrates were mainly related to the carbon sources.

  17. Synergistic Use of Remote Sensing and Modeling to Assess an Anomalously High Chlorophyll-a Event during Summer 2015 in the South Central Red Sea

    Directory of Open Access Journals (Sweden)

    Wenzhao Li

    2017-07-01

    Full Text Available An anomalously high chlorophyll-a (Chl-a event (>2 mg/m3 during June 2015 in the South Central Red Sea (17.5° to 22°N, 37° to 42°E was observed using Moderate Resolution Imaging Spectroradiometer (MODIS data from the Terra and Aqua satellite platforms. This differs from the low Chl-a values (<0.5 mg/m3 usually encountered over the same region during summertime. To assess this anomaly and possible causes, we used a wide range of oceanographical and meteorological datasets, including Chl-a concentrations, sea surface temperature (SST, sea surface height (SSH, mixed layer depth (MLD, ocean current velocity and aerosol optical depth (AOD obtained from different sensors and models. Findings confirmed this anomalous behavior in the spatial domain using Hovmöller data analysis techniques, while a time series analysis addressed monthly and daily variability. Our analysis suggests that a combination of factors controlling nutrient supply contributed to the anomalous phytoplankton growth. These factors include horizontal transfer of upwelling water through eddy circulation and possible mineral fertilization from atmospheric dust deposition. Coral reefs might have provided extra nutrient supply, yet this is out of the scope of our analysis. We thought that dust deposition from a coastal dust jet event in late June, coinciding with the phytoplankton blooms in the area under investigation, might have also contributed as shown by our AOD findings. However, a lag cross correlation showed a two- month lag between strong dust outbreak and the high Chl-a anomaly. The high Chl-a concentration at the edge of the eddy emphasizes the importance of horizontal advection in fertilizing oligotrophic (nutrient poor Red Sea waters.

  18. Identifying Optimum Landscapes for Water Quality and Ecosystem Services in an Agricultural Watershed

    Science.gov (United States)

    Dalzell, B. J.; Pennington, D. N.; Mulla, D.; Polasky, S.; Taff, S.; Nelson, E.

    2011-12-01

    Many areas in the US fail to meet water quality standards. Management actions to improve water quality also impact other ecosystem services, both positively and negatively. We developed an integrated approach to analyze how to meet various levels of water quality while maximizing the net benefits of other ecosystem services in an agricultural watershed. We used the SWAT model (Soil and Water Assessment Tool) to predict crop yield, flow, sediment and phosphorus export and the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model to estimate market returns from agriculture production and non-market values from sediment and phosphorus reduction and from carbon sequestration. We applied these models to an agricultural watershed located in South Central Minnesota to find optimal landscape arrangement for a range of water quality goals. Results showed that the current landscape is near the economic optimum and that market returns from agricultural production dominate total economic returns, even when ecosystem services such as water quality and carbon sequestration are valued. We find that land use patterns that achieve 50% reductions in sediment and phosphorus result in significant annual losses in economic returns (averaging approximately 300/ha and 250/ha for sediment and phosphorus, respectively). When including non-market valuation of ecosystem services, 50% reductions in sediment and phosphorus result in declines in total watershed value an average of about 220/ha and 180/ha for sediment and phosphorus, respectively. However, compared to the current landscape, we show that marginal water quality improvements (10-15% reductions in sediment and phosphorus) could be achieved with no net loss in economic returns. Further, when ecosystem service valuation is included, reductions in sediment and phosphorus on the order of 15-20%, respectively, could be achieved with no net loss of total value. Landscape changes to achieve sediment and phosphorus

  19. Application of Watershed Scale Models to Predict Nitrogen Loading From Coastal Plain Watersheds

    Science.gov (United States)

    George M. Chescheir; Glenn P Fernandez; R. Wayne Skaggs; Devendra M. Amatya

    2004-01-01

    DRAINMOD-based watershed models have been developed and tested using data collected from an intensively instrumented research site on Kendricks Creek watershed near Plymouth. NC. These models were applied to simulate the hydrology and nitrate nitrogen (NO3-N) loading from two other watersheds in the Coastal Plain of North Carolina, the 11600 ha Chicod Creek watershed...

  20. Review of Watershed Water Quality Models

    National Research Council Canada - National Science Library

    Deliman, Patrick

    1999-01-01

    .... Several available watershed water quality models were reviewed and rated with regard to their potential in being utilized as the building block for the development of a Corps of Engineers watershed water quality model...

  1. DNR Watersheds - DNR Level 02 - HUC 04

    Data.gov (United States)

    Minnesota Department of Natural Resources — These data consists of watershed delineations in one seamless dataset of drainage areas called Minnesota Department of Natural Resources (DNR) Level 02 Watersheds....

  2. Application of SELECT and SWAT models to simulate source load, fate, and transport of fecal bacteria in watersheds.

    Science.gov (United States)

    Ranatunga, T.

    2017-12-01

    Modeling of fate and transport of fecal bacteria in a watershed is a processed based approach that considers releases from manure, point sources, and septic systems. Overland transport with water and sediments, infiltration into soils, transport in the vadose zone and groundwater, die-off and growth processes, and in-stream transport are considered as the other major processes in bacteria simulation. This presentation will discuss a simulation of fecal indicator bacteria source loading and in-stream conditions of a non-tidal watershed (Cedar Bayou Watershed) in South Central Texas using two models; Spatially Explicit Load Enrichment Calculation Tool (SELECT) and Soil and Water Assessment Tool (SWAT). Furthermore, it will discuss a probable approach of bacteria source load reduction in order to meet the water quality standards in the streams. The selected watershed is listed as having levels of fecal indicator bacteria that posed a risk for contact recreation and wading by the Texas Commission of Environmental Quality (TCEQ). The SELECT modeling approach was used in estimating the bacteria source loading from land categories. Major bacteria sources considered were, failing septic systems, discharges from wastewater treatment facilities, excreta from livestock (Cattle, Horses, Sheep and Goat), excreta from Wildlife (Feral Hogs, and Deer), Pet waste (mainly from Dogs), and runoff from urban surfaces. The estimated source loads from SELECT model were input to the SWAT model, and simulate the bacteria transport through the land and in-stream. The calibrated SWAT model was then used to estimate the indicator bacteria in-stream concentrations for future years based on regional land use, population and household forecast (up to 2040). Based on the reductions required to meet the water quality standards in-stream, the corresponding required source load reductions were estimated.

  3. Geothermal reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, C.R.; Golabi, K.

    1978-02-01

    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  4. Estimating irrigation water demand using an improved method and optimizing reservoir operation for water supply and hydropower generation: a case study of the Xinfengjiang reservoir in southern China

    Science.gov (United States)

    Wu, Yiping; Chen, Ji

    2013-01-01

    The ever-increasing demand for water due to growth of population and socioeconomic development in the past several decades has posed a worldwide threat to water supply security and to the environmental health of rivers. This study aims to derive reservoir operating rules through establishing a multi-objective optimization model for the Xinfengjiang (XFJ) reservoir in the East River Basin in southern China to minimize water supply deficit and maximize hydropower generation. Additionally, to enhance the estimation of irrigation water demand from the downstream agricultural area of the XFJ reservoir, a conventional method for calculating crop water demand is improved using hydrological model simulation results. Although the optimal reservoir operating rules are derived for the XFJ reservoir with three priority scenarios (water supply only, hydropower generation only, and equal priority), the river environmental health is set as the basic demand no matter which scenario is adopted. The results show that the new rules derived under the three scenarios can improve the reservoir operation for both water supply and hydropower generation when comparing to the historical performance. Moreover, these alternative reservoir operating policies provide the flexibility for the reservoir authority to choose the most appropriate one. Although changing the current operating rules may influence its hydropower-oriented functions, the new rules can be significant to cope with the increasingly prominent water shortage and degradation in the aquatic environment. Overall, our results and methods (improved estimation of irrigation water demand and formulation of the reservoir optimization model) can be useful for local watershed managers and valuable for other researchers worldwide.

  5. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  6. Cloud GIS Based Watershed Management

    Science.gov (United States)

    Bediroğlu, G.; Colak, H. E.

    2017-11-01

    In this study, we generated a Cloud GIS based watershed management system with using Cloud Computing architecture. Cloud GIS is used as SAAS (Software as a Service) and DAAS (Data as a Service). We applied GIS analysis on cloud in terms of testing SAAS and deployed GIS datasets on cloud in terms of DAAS. We used Hybrid cloud computing model in manner of using ready web based mapping services hosted on cloud (World Topology, Satellite Imageries). We uploaded to system after creating geodatabases including Hydrology (Rivers, Lakes), Soil Maps, Climate Maps, Rain Maps, Geology and Land Use. Watershed of study area has been determined on cloud using ready-hosted topology maps. After uploading all the datasets to systems, we have applied various GIS analysis and queries. Results shown that Cloud GIS technology brings velocity and efficiency for watershed management studies. Besides this, system can be easily implemented for similar land analysis and management studies.

  7. CLOUD GIS BASED WATERSHED MANAGEMENT

    Directory of Open Access Journals (Sweden)

    G. Bediroğlu

    2017-11-01

    Full Text Available In this study, we generated a Cloud GIS based watershed management system with using Cloud Computing architecture. Cloud GIS is used as SAAS (Software as a Service and DAAS (Data as a Service. We applied GIS analysis on cloud in terms of testing SAAS and deployed GIS datasets on cloud in terms of DAAS. We used Hybrid cloud computing model in manner of using ready web based mapping services hosted on cloud (World Topology, Satellite Imageries. We uploaded to system after creating geodatabases including Hydrology (Rivers, Lakes, Soil Maps, Climate Maps, Rain Maps, Geology and Land Use. Watershed of study area has been determined on cloud using ready-hosted topology maps. After uploading all the datasets to systems, we have applied various GIS analysis and queries. Results shown that Cloud GIS technology brings velocity and efficiency for watershed management studies. Besides this, system can be easily implemented for similar land analysis and management studies.

  8. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  9. Watershed Management Optimization Support Tool v3

    Science.gov (United States)

    The Watershed Management Optimization Support Tool (WMOST) is a decision support tool that facilitates integrated water management at the local or small watershed scale. WMOST models the environmental effects and costs of management decisions in a watershed context that is, accou...

  10. Emerging tools and technologies in watershed management

    Science.gov (United States)

    D. Phillip Guertin; Scott N. Miller; David C. Goodrich

    2000-01-01

    The field of watershed management is highly dependent on spatially distributed data. Over the past decade, significant advances have been made toward the capture, storage, and use of spatial data. Emerging tools and technologies hold great promise for improving the scientific understanding of watershed processes and are already revolutionizing watershed research....

  11. Encapsulated microsensors for reservoir interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  12. Watershed Education for Broadcast Meteorologists

    Science.gov (United States)

    Lamos, J. P.; Sliter, D.; Espinoza, S.; Spangler, T. C.

    2006-12-01

    The National Environmental Education and Training Organization (NEETF) published a report in 2005 that summarized the findings of ten years of NEETF and Roper Research. The report stated, "Our years of data from Roper surveys show a persistent pattern of environmental ignorance even among the most educated and influential members of society." Market research has also shown that 80% of television viewers list the weather as the primary reason for watching the local news. Broadcast meteorologists, with a broader understanding of environmental and related sciences have an opportunity to use their weathercasts to inform the public about the environment and the factors that influence environmental health. As "station scientists," broadcast meteorologists can use the weather, and people's connection to it, to broaden their understanding of the environment they live in. Weather and watershed conditions associated with flooding and drought have major human and environmental impacts. Increasing the awareness of the general public about basic aspects of the hydrologic landscape can be an important part of mitigating the adverse effects of too much or too little precipitation, and of protecting the environment as well. The concept of a watershed as a person's natural neighborhood is a very important one for understanding hydrologic and environmental issues. Everyone lives in a watershed, and the health of a watershed is the result of the interplay between weather and human activity. This paper describes an online course to give broadcast meteorologists a basic understanding of watersheds and how watersheds are impacted by weather. It discusses how to convey watershed science to a media- savvy audience as well as how to model the communication of watershed and hydrologic concepts to the public. The course uses a narrative, story-like style to present its content. It is organized into six short units of instruction, each approximately 20 minutes in duration. Each unit is

  13. Chapter 19. Cumulative watershed effects and watershed analysis

    Science.gov (United States)

    Leslie M. Reid

    1998-01-01

    Cumulative watershed effects are environmental changes that are affected by more than.one land-use activity and that are influenced by.processes involving the generation or transport.of water. Almost all environmental changes are.cumulative effects, and almost all land-use.activities contribute to cumulative effects

  14. Multiagent distributed watershed management

    Science.gov (United States)

    Giuliani, M.; Castelletti, A.; Amigoni, F.; Cai, X.

    2012-04-01

    Deregulation and democratization of water along with increasing environmental awareness are challenging integrated water resources planning and management worldwide. The traditional centralized approach to water management, as described in much of water resources literature, is often unfeasible in most of the modern social and institutional contexts. Thus it should be reconsidered from a more realistic and distributed perspective, in order to account for the presence of multiple and often independent Decision Makers (DMs) and many conflicting stakeholders. Game theory based approaches are often used to study these situations of conflict (Madani, 2010), but they are limited to a descriptive perspective. Multiagent systems (see Wooldridge, 2009), instead, seem to be a more suitable paradigm because they naturally allow to represent a set of self-interested agents (DMs and/or stakeholders) acting in a distributed decision process at the agent level, resulting in a promising compromise alternative between the ideal centralized solution and the actual uncoordinated practices. Casting a water management problem in a multiagent framework allows to exploit the techniques and methods that are already available in this field for solving distributed optimization problems. In particular, in Distributed Constraint Satisfaction Problems (DCSP, see Yokoo et al., 2000), each agent controls some variables according to his own utility function but has to satisfy inter-agent constraints; while in Distributed Constraint Optimization Problems (DCOP, see Modi et al., 2005), the problem is generalized by introducing a global objective function to be optimized that requires a coordination mechanism between the agents. In this work, we apply a DCSP-DCOP based approach to model a steady state hypothetical watershed management problem (Yang et al., 2009), involving several active human agents (i.e. agents who make decisions) and reactive ecological agents (i.e. agents representing

  15. Watershed Boundaries, Frederick County, Maryland, watershed management areas that extend to the topographic watershed divide. Watersheds were developed from catchment delineations (2008) by dissolving catchments within larger drainage areas that were previously defined by Fre, Published in 2008, 1:12000 (1in=1000ft) scale, Frederick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Watershed Boundaries dataset current as of 2008. Frederick County, Maryland, watershed management areas that extend to the topographic watershed divide. Watersheds...

  16. Assessment of nutrient loadings of a large multipurpose prairie reservoir

    Science.gov (United States)

    Morales-Marín, L. A.; Wheater, H. S.; Lindenschmidt, K. E.

    2017-07-01

    The relatively low water flow velocities in reservoirs cause them to have high capacities for retaining sediments and pollutants, which can lead to a reduction in downstream nutrient loading. Hence, nutrients can progressively accumulate in reservoirs, resulting in the deterioration of aquatic ecosystems and water quality. Lake Diefenbaker (LD) is a large multipurpose reservoir, located on the South Saskatchewan River (SSR), that serves as a major source of freshwater in Saskatchewan, Canada. Over the past several years, changes in land use (e.g. expansion of urban areas and industrial developments) in the reservoir's catchment have heightened concerns about future water quality in the catchment and in the reservoir. Intensification of agricultural activities has led to an increase in augmented the application of manure and fertilizer for crops and pasture. Although previous research has attempted to quantify nutrient retention in LD, there is a knowledge gap related to the identification of major nutrient sources and quantification of nutrient export from the catchment at different spatial scales. Using the SPAtially Referenced Regression On Watershed (SPARROW) model, this gap has been addressed by assessing water quality regionally, and identifying spatial patterns of factors and processes that affect water quality in the LD catchment. Model results indicate that LD retains about 70% of the inflowing total nitrogen (TN) and 90% of the inflowing total phosphorus (TP) loads, of which fertilizer and manure applied to agricultural fields contribute the greatest proportion. The SPARROW model will be useful as a tool to guide the optimal implementation of nutrient management plans to reduce nutrient inputs to LD.

  17. Soil-Transmitted Helminths and Associated Factors among Pre-School Children in Butajira Town, South-Central Ethiopia: A Community-Based Cross-Sectional Study.

    Science.gov (United States)

    Shumbej, Teha; Belay, Tariku; Mekonnen, Zeleke; Tefera, Tamirat; Zemene, Endalew

    2015-01-01

    Soil-transmitted helminths (STH) remain a major public health problem, particularly in tropical and sub-tropical regions of the world. Though infections are prevalent among all age groups, the world health organization (WHO) considers Pre-school age children (PSAC), school-aged children, and pregnant women as segments of population at high risk of STH morbidities. This study aimed at determining the prevalence and infection intensity of STH and associated factors among PSAC in Butajira Town, south-central Ethiopia. A community-based cross-sectional study was conducted from May to June, 2014 in Butajira Town. The PSAC were selected by systematic sampling technique and invited to participate in the present study. McMaster technique was employed for parasitological analysis of stool samples. Pearson's Chi-square and Fisher's exact tests were performed where appropriate to identify any association between STH infection and independent factors. Multivariate logistic regression model was fitted to identify independent predictors of STH among the PSAC. P-value less than 0.05 was considered statistically significant. A total of 377 (with 96% compliance rate) PSAC were able to provide complete data (socio-demographic information and stool sample). The study showed that 23.3% (88/377) PSAC were infected with one or more species of STH. Ascaris lumbricoides was the most prevalent STH (14.9%) followed by Trichuris trichiura (6.4%). The overall infection intensity, expressed as geometric mean for A. lumbricoides, T. trichiura, and hookworms were 229, 178, and 154 eggs per gram of stool, respectively. The multivariate logistic regression model estimated that being in the age group of 36-47 months (AOR: 2.5, 95% CI: 1.2-5.3, P = 0.016), untrimmed finger nail (AOR: 3.2, 95% CI: 1.8-5.5, P STH infections among the children. The present study showed that STH was a public health problem among PSAC in the study area necessitating annual deworming to control morbidities associated with

  18. Soil-Transmitted Helminths and Associated Factors among Pre-School Children in Butajira Town, South-Central Ethiopia: A Community-Based Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Teha Shumbej

    Full Text Available Soil-transmitted helminths (STH remain a major public health problem, particularly in tropical and sub-tropical regions of the world. Though infections are prevalent among all age groups, the world health organization (WHO considers Pre-school age children (PSAC, school-aged children, and pregnant women as segments of population at high risk of STH morbidities.This study aimed at determining the prevalence and infection intensity of STH and associated factors among PSAC in Butajira Town, south-central Ethiopia.A community-based cross-sectional study was conducted from May to June, 2014 in Butajira Town. The PSAC were selected by systematic sampling technique and invited to participate in the present study. McMaster technique was employed for parasitological analysis of stool samples. Pearson's Chi-square and Fisher's exact tests were performed where appropriate to identify any association between STH infection and independent factors. Multivariate logistic regression model was fitted to identify independent predictors of STH among the PSAC. P-value less than 0.05 was considered statistically significant.A total of 377 (with 96% compliance rate PSAC were able to provide complete data (socio-demographic information and stool sample. The study showed that 23.3% (88/377 PSAC were infected with one or more species of STH. Ascaris lumbricoides was the most prevalent STH (14.9% followed by Trichuris trichiura (6.4%. The overall infection intensity, expressed as geometric mean for A. lumbricoides, T. trichiura, and hookworms were 229, 178, and 154 eggs per gram of stool, respectively. The multivariate logistic regression model estimated that being in the age group of 36-47 months (AOR: 2.5, 95% CI: 1.2-5.3, P = 0.016, untrimmed finger nail (AOR: 3.2, 95% CI: 1.8-5.5, P < 0.001, and not washing hands before a meal (AOR: 3.0, 95% CI: 1.7-5.4, P < 0.001 were independent predictors of STH infections among the children.The present study showed that STH was a

  19. Presence of the tunicate Asterocarpa humilis on ship hulls and aquaculture facilities in the coast of the Biobío Region, south central Chile

    Directory of Open Access Journals (Sweden)

    Javier Pinochet

    2017-08-01

    Full Text Available Non-native ascidians are important members of the fouling community associated with artificial substrata and man-made structures. Being efficient fouling species, they are easily spread by human-mediated transports (e.g., with aquaculture trade and maritime transports. This is exemplified by the ascidian Asterocarpa humilis which displays a wide distribution in the Southern Hemisphere and has been recently reported in the Northern Hemisphere (NW Europe. In continental Chile, its first report dates back from 2000 for the locality of Antofagasta (23°S. Although there was no evidence about the vectors of introduction and spread, nor the source, some authors suggested maritime transport by ship hulls and aquaculture devices as putative introduction pathways and vectors. In the present study, we report for the first time the presence of A. humilis on the hull of an international ship in a commercial port in Concepción bay (36°S, south central Chile. We also found one individual associated to a seashell farm, 70 km far from Concepción bay. Further individuals were subsequently identified within Concepción bay: one juvenile settled upon international harbor pilings and a dozen individuals along aquaculture seashell longlines. For the first specimens sampled, species identification was ascertained using both morphological criteria and molecular barcoding, using the mitochondrial gene cytochrome c oxidase subunit I (COI and a nuclear gene (ribosomal RNA 18S. The nuclear 18S gene and the mitochondrial gene COI clearly assigned the specimens to A. humilis, confirming our morphological identification. Two haplotypes were obtained with COI corresponding to haplotypes previously obtained with European and Northern Chilean specimens. The present study thus reports for the first time the presence of A. humilis in the Araucanian ecoregion, documenting the apparent expansion of this non-native tunicate in Chile over 2,000 km, spanning over three ecoregions

  20. Structural and sedimentary evidence from the northern margin of the Tauride platform in south central Turkey used to test alternative models of Tethys during Early Mesozoic time

    Science.gov (United States)

    Mackintosh, Peter W.; Robertson, Alastair H. F.

    2009-07-01

    Critical to reconstruction of the Tethys ocean is the nature and significance of a reported latest Triassic "Cimmerian" tectonic event in the Tauride Mountains of south central Turkey. In one published model, a "Cimmerian" continental fragment, including the Tauride platform rifted from the northern margin of Gondwana and collided with a Eurasian-derived "Anatolide" continental fragment during Late Triassic time, causing orogenic deformation of the Tauride continental platform. In a second published model, southward subduction of a Palaeotethyan ocean opened a back-arc basin associated with rift-related uplift of the Tauride platform during Early Triassic time. The Tauride platform remained as a north-facing passive margin from the Mid-Late Triassic to Late Cretaceous without further deformation. In a third published model, a continental fragment rifted from a Tauride-Anatolide platform in the south, opening a small ocean basin (Ankara-İzmir ocean) to the north by Mid-Late Triassic time. Late Triassic deformation and uplift of the Tauride platform possibly resulted from far-field stress transmission from the Cimmerian orogeny that affected the Eurasian margin. In an additional model, a Tauride-Anatolide continent experienced a rift-related evolution, culminating in a pulse of extension-related uplift during the latest Triassic, followed by seafloor spreading to the north. The models are tested using evidence from relatively autochthonous Tauride units (Geyik Dağ; Sultan Dağ) and over-riding thrust sheets (Hadim (Aladağ) nappe; Bolkar nappe). Geological mapping of critical areas and related structural evidence show that most of the deformation in the area can be related to Late Cretaceous and Early Cenozoic (Alpine) emplacement of the Tauride nappes, although Late Triassic compressional deformation is likely at one locality. Sedimentary evidence from the Çayır Formation, a widespread ~ latest Triassic-earliest Jurassic clastic sequence shows that it

  1. Uplift Sequence of the Main Morphoestructural Units of the South Central Andes at 30°S: Insights from a Multidisciplinary Approach

    Science.gov (United States)

    Lossada, A. C.; Mardónez, D.; Suriano, J.; Hoke, G. D.; Fitzgerald, P. G.; Mahoney, J. B.; Giambiagi, L.; Aragon, E.

    2015-12-01

    The South Central Andes at 30°S represent a key area to understand the Andes geodynamics as it corresponds to the flat slab segment, characterized by a subhorizontal subduction angle, absence of Neogene magmatism and a highly compressive tectonic regime. Under these settings, crustal shortening is believed to be the principal mechanism responsible for the rise of the Andes. However, the sequence of uplift of the different morphoestructural units composing the orogen is not fully understood; neither do the location and time of activity of intracrustal detachments and their connection with shallower structures. We attempt to develop a multidisciplinary analysis that allow us to characterize the timing, magnitude and activity of the principal structures involved in the construction of the Andes at 30°S trough the Coastal Range, the Frontal Cordillera and the Precordillera. The main phase of deformation in the Coastal Range occurred between 60 and 40Ma, based on published thermochronological and structural data. Our structural analyses constrain the Frontal Cordillera uplift between 18 and 13Ma. In the Precordillera area, in turn, we carried out structural, sedimentological and U-Pb provenience studies. Provenience studies and the 12 and 9Ma ages obtained for the youngest zircons indicated that the main thrusts uplifting the western sector of the Precordillera thrust system were activated since 13Ma at this latitude, and not before that time as it was previously suggested. In order to better constrain the exhumation and thermal history of Frontal Cordillera, a thermochronological study is being conducted. Twenty samples for apatite fission tracks (AFT) and apatite (U-Th)/He (AHe) were collected from two vertical profiles located at western sector (Guanta granitoid) and eastern sector (Colanguil granitoid) of the Frontal Cordillera system. Samples are currently being processed, and they are partially reseted, which will allow us to obtain a cooling age. The aim is to

  2. P02.05 Peripheral Nerve Sheath Tumor Epidemiology in the South Central Hospital of High Specialty from PEMEX in Mexico

    Science.gov (United States)

    Guerra Mora, J.; Cordoba Mosqueda, M.; Hernandez Resendiz, R.; Loya Aguilar, I.; Vicuña Gonzalez, R.; Garcia Gonzalez, U.

    2016-01-01

    Abstract Introduction: The peripheral sheath tumors are part of a large group of neoplasms that range from biologically benign with minimal disorders in life quality to highly malign with life quality deterioration and high mortality. There are subtypes with high prevalence like Schwannomas and some much rarer like the intracranial peripheral nerve sheath tumor which happen to have very bad prognosis. The aim of this study is to describe the epidemiologic and clinical characteristics of patients with peripheral nerve sheat tumors in a hospital of high specialty. Method and materials: Observational study with patients from March 1999 to March 2016 with confirmed diagnosis of peripheral nerve sheath tumor in the electronic files of the South Central Hospital of High Specialty PEMEX. A statistical analysis is made through the SPSS Statistics of the disease in this Institution program. Results: There were 84 patients with the diagnosis of peripheral nerve sheath tumor with a median age of 48.04 years, 65.5% were males, the most common histological type found was the Schwannoma with a 72.6%, followed by senescent Schwannoma 13.1%, neurofibroma 8.3%, and malign peripheral nerve sheath tumor 2.4%. The most frequent location was at the site of cranial nerves, followed by cervical level 27.4%, lumbar 16.7% and thoracic 9.5%. The most common initial symptom was pain in 23.8% of the patients, and the time of the onset of symptoms to the diagnosis was 31.6 months. From the total of patients 8.3% had neurofibromatosis type 1, 6.0% neurofibromatosis type 2. Conclusions: We realized in our series of reported cases that the frequency is similar to those reported in worldwide population; nevertheless the time between the onset of symptoms and the diagnosis is much higher in our cases as well as the population of patients with neurofibromatosis. This study justifies the need of attention quality improvement and the knowledge of this information the medical doctor of first

  3. Internal dynamics of a paleoaccretionary wedge: insights from combined isotope tectonochronology and sandbox modelling of the South-Central Chilean forearc

    Science.gov (United States)

    Glodny, Johannes; Lohrmann, Jo; Echtler, Helmut; Gräfe, Kirsten; Seifert, Wolfgang; Collao, Santiago; Figueroa, Oscar

    2005-02-01

    Forearc accretionary wedges are cyclic systems in which material is frontally and/or basally accreted. Material cycling involves underthrusting, subduction, underplating, exhumation, erosion, transfer to the trench and underthrusting again. In this study we present a novel, tectonochronologic approach to constrain long-term exhumation rates of basally accreted wedge complexes, based on isotopic dating of structural features, on petrological data and sandbox analogue simulations. Congruence between the structural inventory in nature and structures generated in scaled sandbox experiments allows detailed insights into wedge dynamics. For the present-day surface material of the paleoaccretionary wedge of South-Central Chile (Valdivia area, 40°S), published U-Pb ages of detrital zircon place a maximum age of ˜278 Ma for subduction. Prograde metamorphism at transitional greenschist to blueschist facies conditions (420 °C, 8-9 kbar) was immediately followed by progressive penetrative deformation associated with basal accretion, dated at ˜250-245 Ma using Rb/Sr internal mineral isochrons. The accretion process involved duplex tectonics and antiformal stacking, with formation of near-horizontal mylonitic shear zones at around 241 Ma. Continuous basal accretion at depth gave rise to an extensional tectonic regime at higher structural levels. Both semi-ductile, small-scale extensional shear zones and post-kinematic vein mineralizations yield Rb/Sr ages of ˜235 Ma. Tension gashes, representing the latest isotopically dateable stage of structural evolution, were formed at ˜210 Ma, at conditions of ˜230 °C at 1.5-3 kbar, as constrained by fluid inclusion data. Zircon fission track data indicate final cooling to below ˜200 °C at 186±24 Ma. The results suggest continuous basal accretion for at least 50 Ma, with long-term average exhumation rates of 0.6±0.2 mm/a, most probably outbalanced by similar long-term average erosion rates. Changing plate boundary conditions at

  4. Presence of the tunicateAsterocarpa humilison ship hulls and aquaculture facilities in the coast of the Biobío Region, south central Chile.

    Science.gov (United States)

    Pinochet, Javier; Leclerc, Jean-Charles; Brante, Antonio; Daguin-Thiébaut, Claire; Díaz, Christian; Tellier, Florence; Viard, Frédérique

    2017-01-01

    Non-native ascidians are important members of the fouling community associated with artificial substrata and man-made structures. Being efficient fouling species, they are easily spread by human-mediated transports (e.g., with aquaculture trade and maritime transports). This is exemplified by the ascidian Asterocarpa humilis which displays a wide distribution in the Southern Hemisphere and has been recently reported in the Northern Hemisphere (NW Europe). In continental Chile, its first report dates back from 2000 for the locality of Antofagasta (23°S). Although there was no evidence about the vectors of introduction and spread, nor the source, some authors suggested maritime transport by ship hulls and aquaculture devices as putative introduction pathways and vectors. In the present study, we report for the first time the presence of A. humilis on the hull of an international ship in a commercial port in Concepción bay (36°S), south central Chile. We also found one individual associated to a seashell farm, 70 km far from Concepción bay. Further individuals were subsequently identified within Concepción bay: one juvenile settled upon international harbor pilings and a dozen individuals along aquaculture seashell longlines. For the first specimens sampled, species identification was ascertained using both morphological criteria and molecular barcoding, using the mitochondrial gene cytochrome c oxidase subunit I (COI) and a nuclear gene (ribosomal RNA 18S). The nuclear 18S gene and the mitochondrial gene COI clearly assigned the specimens to A. humilis, confirming our morphological identification. Two haplotypes were obtained with COI corresponding to haplotypes previously obtained with European and Northern Chilean specimens. The present study thus reports for the first time the presence of A. humilis in the Araucanian ecoregion, documenting the apparent expansion of this non-native tunicate in Chile over 2,000 km, spanning over three ecoregions. In addition

  5. Time variations of gaseous and reactive mercury in the industrial area of Puertollano (south-central Spain). Temporal cycles with marked variations

    Science.gov (United States)

    Martínez-Coronado, Alba; Esbrí, Jose Maria; Higueras, Pablo

    2016-06-01

    Puertollano (48,086 inhabitants) is the largest industrial city in the Castilla-La Mancha region (South-Central Spain). The city is located some 250 km South of Madrid; it was an important coal mining site during the last century and today it is the location of one of the most important Spanish oil refineries and the only refinery located away from the coast. Nowadays the area (which mainly includes the Ojailen valley) has a large open pit coal mine (Encasur), two power plants (Eon and Elcogas) and a petrochemical complex (Repsol) located S and SE from the town. These industries give rise to a complex scenario in terms of mercury emissions to the atmosphere: Repsol, Elcogas and Eon act as discrete sources, while coal mine and dumps acts as a general, diffuse source. The mercury contents in Puertollano town and the related industrial area were characterized during 2010 and 2011 by acquiring stationary data of Gaseous Elemental Mercury (GEM), Reactive Gaseous Mercury (RGM), meteorological parameters and other atmospheric contaminants (NO, NO2, SO2, benzene, toluene, xylene, ozone and PM10). In addition, several Total Gaseous Mercury (TGM) mobile surveys were carried out covering the Ojailen valley. Total Gaseous Mercury (TGM) in the whole valley was in the range 0-24 ng m-3 in all surveys, while higher levels were found near to the coal mine and in the vicinity of a coal power plant that employs clean technology (Elcogas). Tekran data showed low GEM levels during 2010-2011 (1.81 ng m-3 on average), while lower GEM levels were measured during autumn and summer, and maximum levels in spring (7.32 ng m-3 on average). RGM measurements were 0.0088 ng m-3, i.e., significantly lower than background levels in the USA and Europe (0.04 ng m-3). Concentrations of these mercury species' were higher during summer (0.0117 ng m-3). Multiple regression analysis was carried out and good relationships between GEM levels, meteorological parameters and other pollutants were identified

  6. A metabolism-based whole lake eutrophication model to estimate the magnitude and time scales of the effects of restoration in Upper Klamath Lake, south-central Oregon

    Science.gov (United States)

    Wherry, Susan A.; Wood, Tamara M.

    2018-04-27

    A whole lake eutrophication (WLE) model approach for phosphorus and cyanobacterial biomass in Upper Klamath Lake, south-central Oregon, is presented here. The model is a successor to a previous model developed to inform a Total Maximum Daily Load (TMDL) for phosphorus in the lake, but is based on net primary production (NPP), which can be calculated from dissolved oxygen, rather than scaling up a small-scale description of cyanobacterial growth and respiration rates. This phase 3 WLE model is a refinement of the proof-of-concept developed in phase 2, which was the first attempt to use NPP to simulate cyanobacteria in the TMDL model. The calibration of the calculated NPP WLE model was successful, with performance metrics indicating a good fit to calibration data, and the calculated NPP WLE model was able to simulate mid-season bloom decreases, a feature that previous models could not reproduce.In order to use the model to simulate future scenarios based on phosphorus load reduction, a multivariate regression model was created to simulate NPP as a function of the model state variables (phosphorus and chlorophyll a) and measured meteorological and temperature model inputs. The NPP time series was split into a low- and high-frequency component using wavelet analysis, and regression models were fit to the components separately, with moderate success.The regression models for NPP were incorporated in the WLE model, referred to as the “scenario” WLE (SWLE), and the fit statistics for phosphorus during the calibration period were mostly unchanged. The fit statistics for chlorophyll a, however, were degraded. These statistics are still an improvement over prior models, and indicate that the SWLE is appropriate for long-term predictions even though it misses some of the seasonal variations in chlorophyll a.The complete whole lake SWLE model, with multivariate regression to predict NPP, was used to make long-term simulations of the response to 10-, 20-, and 40-percent

  7. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    Directory of Open Access Journals (Sweden)

    S. A. Watmough

    2002-01-01

    Full Text Available The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario. In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1 from

  8. Late Quaternary alluvial fans of Emli Valley in the Ecemiş Fault Zone, south central Turkey: Insights from cosmogenic nuclides

    Science.gov (United States)

    Akif Sarıkaya, M.; Yıldırım, Cengiz; Çiner, Attila

    2015-01-01

    Alluvial fans within the paraglacial Ecemiş River drainages on the Aladağlar Mountains in south central Turkey were studied using geomorphological, sedimentological, and chlorine-36 terrestrial cosmogenic nuclide (TCN) surface exposure dating methods to examine the timing of alluvial fan abandonment/incision, and to understand the role of climatic and tectonic processes in the region. These alluvial fan complexes are among the best-preserved succession of alluvial fans in Turkey and they were offset by the major strike-slip Ecemiş Fault of the Central Anatolian Fault Zone. The alluvial fans are mostly composed of well-lithified limestone cobbles (5 to 25 cm in size), and comprise crudely stratified thick beds with a total thickness reaching up to about 80 m. TCN surface exposure dating indicates that the oldest alluvial fan surface (Yalak Fan) was likely formed and subsequently abandoned latest by 136.0 ± 23.4 ka ago, largely on the transition of the Penultimate Glaciation (Marine Isotope Stage 6, MIS 6) to the Last Interglacial (MIS 5) (i.e. Termination II). The second set of alluvial fan (Emli Fan) was possibly developed during the Last Interglacial (MIS 5), and incised twice by between roughly 97.0 ± 13.8 and 81.2 ± 13.2 ka ago. A younger alluvial fan deposit placed on relatively older erosional terraces of the Emli Fan suggests that it may have been produced during the Last Glacial Cycle (MIS 2). These events are similar to findings from other fluvial and lacustrine deposits throughout central Anatolia. The incision times of the Ecemiş alluvial fan surfaces largely coincide with major climatic shifts from the cooler glacial periods to warmer interglacial/interstadial conditions. This indicates that alluvial fans were produced by outwash sediments of paleoglaciers during cooler conditions, and, later, when glaciers started to retreat due to a major warming event, the excess water released from the glaciers incised the pre-existing fan surfaces. An

  9. Water-table decline in the south-central Great Basin during the Quaternary Period; implications for toxic-waste disposal

    Science.gov (United States)

    Winograd, I.J.; Szabo, B. J.

    1986-01-01

    The distribution of vein calcite, tufa, and other features indicative of paleo-groundwater discharge, indicates that during the early to middle Pleistocene, the water table at Ash Meadows, in the Amargosa Desert, Nevada, and at Furnace Creek Wash, in east-central Death Valley, California, was tens to hundreds of meters above the modern water table, and that groundwater discharge occurred up to 18 km up-the-hydraulic gradient from modern discharge areas. Uranium series dating of the calcitic veins permits calculation of rates of apparent water table decline; rates of 0.02 to 0.08 m/1000 yr are indicated for Ash meadows and 0.2 to 0.6 m/1000 yr for Furnace Creek Wash. The rates for Furnace Creek Wash closely match a published estimate of vertical crustal offset for this area, suggesting that tectonism is a major cause for the displacement observed. In general, displacements of the paleo-water table probably reflect a combination of: (a) tectonic uplift of vein calcite and tufa, unaccompanied by a change in water table altitude; (b) decline in water table altitude in response to tectonic depression of areas adjacent to dated veins and associated tufa; (c) decline in water table altitude in response to increasing aridity caused by major uplift of the Sierra Nevada and Transverse Ranges during the Quaternary; and (d) decline in water altitude in response to erosion triggered by increasing aridity and/or tectonism. A synthesis of geohydrologic, neotectonic, and paleoclimatologic information with the vein-calcite data permits the inference that the water table in the south-central Great Basin progressively lowered throughout the Quaternary. This inference is pertinent to an evaluation of the utility of thick (200-600 m) unsaturated zones of the region for isolating solidified radioactive wastes from the hydrosphere for hundreds of millenia. Wastes buried a few tens to perhaps 100 m above the modern water table--that is above possible water level rises due to future

  10. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    Science.gov (United States)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  11. Geochemical studies in watersheds expanded

    Science.gov (United States)

    Church, M. Robbins

    In the past, geochemical research in forested watersheds has focused on understanding the basic processes that occur in soils and rocks. Watershed geochemical processes, however, are greatly influenced by, and in turn, greatly influence, both organisms and biological process in soils, and hydrologic responses of catchments. To date, geochemical research has dealt principally with basic chemical processes in soils and rocks, and much less with questions concerning hydrologic routing through catchments and the effects such routing has on temporal variation in chemical composition of surface waters.Research on flow generation in catchments has focused on intensive field studies on plots, hillslope sections, and small catchments, with extension to larger scales necessarily involving the application of conceptual models that might (or might not) be valid. The acquisition of direct experimental evidence (for example, verifying flow generation mechanisms) on larger-scale watersheds has always been problematic. Although geochemists understand that the explanation of some geochemical observations requires that flow pathways be explicitly identified, and hydrologists understand that flow generation can be better elucidated if the geochemical history of waters is known, critical integrated communication between the disciplines is often lacking. In turn, biologists require physical and geochemical information to interpret biological effects in watersheds, and hydrologists and geochemists need to be aware of the effects of biological processes on hydrochemical response of catchments.

  12. 10 Watershed Disturbance.cdr

    African Journals Online (AJOL)

    Administrator

    plant species and several endemic butterfly species like N. lamborni and B. ... been colonized by invasive species notably the Siam weed ..... to climate change. If these activities are not checked, the water bodies which owe their existence to the watershed will be negatively affected. Conclusion. The study examined the ...

  13. RESERVOIR CHARACTERIZATION OF THE LOWER GREEN RIVER FORMATION, SOUTHWEST UINTA BASIN, UTAH

    Energy Technology Data Exchange (ETDEWEB)

    S. Robert Bereskin

    2003-02-11

    Anastamosing, low gradient distributary channels produce {approx}30 gravity, paraffinic oils from the Middle Member of the lacustrine Eocene Green River Formation in the south-central portion of the Uinta Basin. This localized depocenter was situated along the fluctuating southern shoreline of Lake Uinta, where complex deposits of marginal-lacustrine to lower delta plain accumulations are especially characteristic. The Middle Member contains several fining-upward parasequences that can be recognized in outcrop, core, and downhole logs. Each parasequence is about 60 to 120 feet thick and consists of strata deposited during multiple lake level fluctuations that approach 30 to 35 feet in individual thickness. Such parasequences represent 300,000-year cycles based on limited absolute age dating. The subaerial to subaqueous channels commonly possess an erosional base and exhibit a fining upward character. Accordingly, bedding features commonly range from large-scale trough and planar cross bedding or lamination at the base, to a nonreservoir, climbing ripple assemblage near the uppermost reservoir boundary. The best reservoir quality occurs within the laminated to cross-stratified portions, and the climbing ripple phase usually possesses more deleterious micas and/or detrital clays. Diagenesis also exerts a major control on reservoir quality. Certain sandstones were cemented by an early, iron-poor calcite cement, which can be subsequently leached. Secondary intergranular porosity (up to 20%) is largely responsible for the 10 -100 millidarcy rock, which represents petrophysical objectives for both primary and secondary production. Otherwise, intense compaction, silicic and iron-rich carbonate cements, and authigenic clays serve to reduce reservoir quality to marginal economic levels.

  14. A review of reservoir desiltation

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation......physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation...

  15. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  16. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  17. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  18. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... 50% calcite, leaving the remaining internal surface to the fine grained silica and clay. The high specific surface of these components causes clay- and silica rich intervals to have high irreducible water saturation. Although chalks typically are found to be water wet, chalk with mixed wettability...... stabilizes chemically by recrystallization. This process requires energy and is promoted by temperature. This recrystallization in principle does not influence porosity, but only specific surface, which decreases during recrystallization, causing permeability to increase. The central North Sea is a warm...

  19. Pacifiers: a microbial reservoir.

    Science.gov (United States)

    Comina, Elodie; Marion, Karine; Renaud, François N R; Dore, Jeanne; Bergeron, Emmanuelle; Freney, Jean

    2006-12-01

    The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.

  20. Urban stormwater flood management in the Cordeiro watershed, Sao Paulo, Brazil: does the interaction between socio-political and technical aspects create an opportunity to attain community resilience?

    NARCIS (Netherlands)

    Borba, M.L.; Warner, J.F.; Porto, M.F.A.

    2016-01-01

    In the urban Cordeiro watershed, São Paulo, Brazil, the impervious surface has reduced stormwater infiltration and the drainage system has become insufficient. Engineering firms have been contracted, under government supervision, to implement the construction of six water reservoirs in order to

  1. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  2. Phytoplankton assemblage of a small, shallow, tropical African reservoir.

    Science.gov (United States)

    Mustapha, Moshood K

    2009-12-01

    I measured physico-chemical properties and phytoplankton in the small, shallow tropical reservoir of Oyun (Offa, Nigeria) between January 2002 and December 2003. I identified 25 phytoplankton genera in three sampling stations. Bacillariophyceae dominated (75.3%), followed by Chlorophyceae (12.2%), Cyanobacteria (11.1%) and Desmidiaceae (0.73%). The high amount of nutrients (e.g. nitrate, phosphate, sulphate and silica) explain phytoplankton heterogeneity (p<0.05). Phytoplankton was abundant during the rainy season, but the transition period had the richest assemblage and abundance. Fluctuations in phytoplankton density were a result of seasonal changes in concentration of nutrients, grazing pressure and reservoir hydrology. The reservoir is eutrophic with excellent water quality and a diverse phytoplankton assemblage: fish production would be high. These conditions resulted from strategies such as watershed best management practices (BMPs) to control eutrophication and sedimentation, and priorities for water usage established through legislation. Additional measures are recommended to prevent oligotrophy, hypereutrophy, excessive phytoplankton bloom, toxic cyanobacteria, and run-off of organic waste and salts.

  3. Gravity observations for hydrocarbon reservoir monitoring

    NARCIS (Netherlands)

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The

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

    Science.gov (United States)

    Harrison, J.A.; Maranger, R.J.; Alexander, Richard 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 (<50 km2) were critical in the analysis, retaining almost half (9.3 Tg N year -1) of the 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

  5. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  6. Well testing in gas hydrate reservoirs

    OpenAIRE

    Kome, Melvin Njumbe

    2015-01-01

    Reservoir testing and analysis are fundamental tools in understanding reservoir hydraulics and hence forecasting reservoir responses. The quality of the analysis is very dependent on the conceptual model used in investigating the responses under different flowing conditions. The use of reservoir testing in the characterization and derivation of reservoir parameters is widely established, especially in conventional oil and gas reservoirs. However, with depleting conventional reserves, the ...

  7. [Relationships between landscape pattern and water quality at western reservoir area in Shenzhen City].

    Science.gov (United States)

    Yue, Jun; Wang, Yang-lin; Li, Gui-cai; Wu, Jian-sheng; Xie, Miao-miao

    2008-01-01

    In this paper, the relationships between landscape pattern and water quality at western reservoir area in Shenzhen City were studied with grey connection method, and the influences of source' and 'sink' landscape patterns on non-point pollution were probed. The results showed that the dominance, adjacency, and fragmentation of 'source' and 'sink' landscapes could markedly influence the water quality. From 2000 to 2001, due to the changes of the 'source' and 'sink' landscape patterns in research areas, the output of pollutants increased and the reduction of pollution decreased, resulting in the deterioration of water quality of three reservoirs. According to the spatial distribution of 'source' and 'sink' landscapes, it was found that the distribution of 'sink' landscapes at the middle-lower reaches of the watersheds had close relationships with the changes of reservoir water quality, suggesting that 'sink' landscape pattern was of significance in the management of non-point pollution.

  8. Rainfall-Runoff and Water-Balance Models for Management of the Fena Valley Reservoir, Guam

    Science.gov (United States)

    Yeung, Chiu W.

    2005-01-01

    The U.S. Geological Survey's Precipitation-Runoff Modeling System (PRMS) and a generalized water-balance model were calibrated and verified for use in estimating future availability of water in the Fena Valley Reservoir in response to various combinations of water withdrawal rates and rainfall conditions. Application of PRMS provides a physically based method for estimating runoff from the Fena Valley Watershed during the annual dry season, which extends from January through May. Runoff estimates from the PRMS are used as input to the water-balance model to estimate change in water levels and storage in the reservoir. A previously published model was calibrated for the Maulap and Imong River watersheds using rainfall data collected outside of the watershed. That model was applied to the Almagosa River watershed by transferring calibrated parameters and coefficients because information on daily diversions at the Almagosa Springs upstream of the gaging station was not available at the time. Runoff from the ungaged land area was not modeled. For this study, the availability of Almagosa Springs diversion data allowed the calibration of PRMS for the Almagosa River watershed. Rainfall data collected at the Almagosa rain gage since 1992 also pr