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Sample records for agricultural central valley

  1. Mapping Evapotranspiration over Agricultural Land in the California Central Valley

    NASA Astrophysics Data System (ADS)

    Melton, F. S.; Huntington, J. L.; Guzman, A.; Johnson, L.; Morton, C.; Nemani, R. R.; Post, K. M.; Rosevelt, C.; Shupe, J. W.; Spellenberg, R.; Vitale, A.

    2015-12-01

    Recent advances in satellite mapping of evapotranspiration (ET) have made it possible to largely automate the process of mapping ET over large areas at the field-scale. This development coincides with recent drought events across the western U.S. which have intensified interest in mapping of ET and consumptive use to address a range of water management challenges, including resolving disputes over water rights, improving irrigation management, and developing sustainable management plans for groundwater resources. We present a case study for California that leverages two automated ET mapping capabilities to estimate ET at the field scale over agricultural areas in the California Central Valley. We utilized the NASA Earth Exchange and applied a python-based implementation of the METRIC surface energy balance model and the Satellite Irrigation Management Support (SIMS) system, which uses a surface reflectance-based approach, to map ET over agricultural areas in the Central Valley. We present estimates from 2014 from both approaches and results from a comparison of the estimates. Though theoretically and computationally quite different from each other, initial results from both approaches show good agreement overall on seasonal ET totals for 2014. We also present results from comparisons against ET measurements collected on commercial farms in the Central Valley and discuss implications for accuracy of the two different approaches. The objective of this analysis is to provide data that can inform planning for the development of sustainable groundwater management plans, and assist water managers and growers in evaluating irrigation demand during drought events.

  2. Climate Impacts on Irrigated Agriculture in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Winter, J.; Young, C. A.; Mehta, V. K.; Davitt, A. W. D.; Azarderakhsh, M.; Ruane, A. C.; Rosenzweig, C.

    2015-12-01

    Irrigated farms account for 80%-90% of consumptive water use in the United States and $118.5 billion of US agricultural production. Despite the vast water use and high yields of irrigated croplands, agriculture is typically the lowest value sector in a water resources system, and thus the first to face reductions when water becomes scarce. A major challenge for hydrologic and agricultural communities is assessing the effects of climate change on the sustainability of regional water resources and irrigated agriculture. To explore the interface of water and agriculture in California's Central Valley, the Decision Support System for Agrotechnology Transfer (DSSAT) crop model was coupled to the Water Evaluation and Planning System (WEAP) water resources model, deployed over the service area of Yolo County Flood Control and Water Conservation District, and forced using both historical and future climate scenarios. This coupling brings water supply constraints to DSSAT and sophisticated agricultural water use, management, and diagnostics to WEAP. Thirty year historical (1980-2009) simulations of WEAP-DSSAT for corn, wheat, and rice were run using a spatially interpolated observational dataset, and contrasted with future simulations using climate scenarios developed by adjusting the spatially interpolated observational dataset with North American Regional Climate Change Assessment Program differences between future (2050-2069) and historical (1980-1999) regional climate model simulations of precipitation and temperature. Generally, within the Central Valley temperatures warm by approximately 2°C, precipitation remains constant, and crop water use efficiency increases. On average corn yields decrease, wheat yields increase, and rice yields remain unchanged. Potential adaptations, as well as implications for groundwater pumping, irrigation extent and method, and land use change including fallowing and switching crops, are examined.

  3. Mapping Drought Impacts on Agricultural Production in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Melton, F. S.; Guzman, A.; Johnson, L.; Rosevelt, C.; Verdin, J. P.; Dwyer, J. L.; Mueller, R.; Zakzeski, A.; Thenkabail, P. S.; Wallace, C.; Jones, J.; Windell, S.; Urness, J.; Teaby, A.; Hamblin, D.; Post, K. M.; Nemani, R. R.

    2014-12-01

    The ongoing drought in California has substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to requests for local water transfers, county drought disaster designations, and allocation of emergency funds to mitigate drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in idle acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to timeseries of data from Landsat TM, ETM+, OLI, and MODIS. Our effort has been focused on development of indicators of drought impacts in the March - August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 640 fields from March - September, 2014. We present the algorithm along with updated results from the accuracy assessment, and discuss potential applications to other regions.

  4. Climate Change Impacts on Water Resources and Irrigated Agriculture in the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Winter, J.; Young, C. A.; Azarderakhsh, M.; Ruane, A. C.; Rosenzweig, C.

    2013-12-01

    Agricultural productivity is strongly dependent on the availability of water, necessitating accurate projections of water resources, the allocation of water resources across competing sectors, and the effects of insufficient water resources on crops to assess the impacts of climate change on agricultural productivity. To explore the interface of water and agriculture in California's Central Valley, the Decision Support System for Agrotechnology Transfer (DSSAT) crop model was coupled to the Water Evaluation and Planning System (WEAP) water resources model, deployed over the region, and run using both historical and future climate scenarios. This coupling brings water supply constraints to DSSAT and sophisticated agricultural water use, management, and diagnostics to WEAP. A 30-year simulation of WEAP-DSSAT forced using a spatially interpolated observational dataset was run from 1980-2009. Moderate Resolution Imaging Spectroradiometer Surface Resistance and Evapotranspiration (MOD16) and Terrestrial Observation and Prediction System (TOPS) data were used to evaluate WEAP-DSSAT evapotranspiration calculations. Overall WEAP-DSSAT reasonably captures the seasonal cycle of observed evapotranspiration, but some catchments contain significant biases. Future climate scenarios were constructed by adjusting the spatially interpolated observational dataset with North American Regional Climate Change Assessment Program differences between future (2050-2069) and historical (1980-1999) regional climate model simulations of precipitation and temperature. Generally, within the Central Valley temperatures warm by approximately 2°C, precipitation remains constant, and crop water use efficiency increases. The overall impacts of future climate on irrigated agricultural yields varies across the Central Valley and is highly dependent on crop, water resources demand assumptions, and agricultural management.

  5. Hydro-economic analysis of groundwater pumping for irrigated agriculture in California's Central Valley, USA

    NASA Astrophysics Data System (ADS)

    Medellín-Azuara, Josué; MacEwan, Duncan; Howitt, Richard E.; Koruakos, George; Dogrul, Emin C.; Brush, Charles F.; Kadir, Tariq N.; Harter, Thomas; Melton, Forrest; Lund, Jay R.

    2015-09-01

    As in many places, groundwater in California (USA) is the major alternative water source for agriculture during drought, so groundwater's availability will drive some inevitable changes in the state's water management. Currently, agricultural, environmental, and urban uses compete for groundwater, resulting in substantial overdraft in dry years with lowering of water tables, which in turn increases pumping costs and reduces groundwater pumping capacity. In this study, SWAP (an economic model of agricultural production and water use in California) and C2VISim (the California Department of Water Resources groundwater model for California's Central Valley) are connected. This paper examines the economic costs of pumping replacement groundwater during drought and the potential loss of pumping capacity as groundwater levels drop. A scenario of three additional drought years continuing from 2014 show lower water tables in California's Central Valley and loss of pumping capacity. Places without access to groundwater and with uncertain surface-water deliveries during drought are the most economically vulnerable in terms of crop revenues, employment and household income. This is particularly true for Tulare Lake Basin, which relies heavily on water imported from the Sacramento-San Joaquin Delta. Remote-sensing estimates of idle agricultural land between 2012 and 2014 confirm this finding. Results also point to the potential of a portfolio approach for agriculture, in which crop mixing and conservation practices have substantial roles.

  6. Drought Impacts on Agricultural Production and Land Fallowing in California's Central Valley in 2015

    NASA Astrophysics Data System (ADS)

    Rosevelt, C.; Melton, F. S.; Johnson, L.; Guzman, A.; Verdin, J. P.; Thenkabail, P. S.; Mueller, R.; Jones, J.; Willis, P.

    2015-12-01

    The ongoing drought in California substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to mitigation of drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in fallow acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to timeseries of data from Landsat TM, ETM+, OLI, and MODIS. Our effort has been focused on development of indicators of drought impacts in the March - August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 650 fields from March - September in 2014 and 2015. We present the algorithm along with updated results from the accuracy assessment, and data and maps of land fallowing in the Central Valley in 2015.

  7. Drought Impacts on Agricultural Production and Land Fallowing in California's Central Valley in 2015

    NASA Technical Reports Server (NTRS)

    Rosevelt, Carolyn; Melton, Forrest S.; Johnson, Lee; Guzman, Alberto; Verdin, James P.; Thenkabail, Prasad S.; Mueller, Rick; Jones, Jeanine; Willis, Patrick

    2016-01-01

    The ongoing drought in California substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to mitigation of drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in fallow acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to time-series data from Landsat TM (Thematic Mapper), ETM+ (Enhanced Thematic Mapper Plus), OLI (Operational Land Imager), and MODIS (Moderate Resolution Imaging Spectroradiometer). Our effort has been focused on development of indicators of drought impacts in the March-August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 650 fields from March-September in 2014 and 2015. We present the algorithm along with updated results from the accuracy assessment, and data and maps of land fallowing in the Central Valley in 2015.

  8. Quality of ground water in agricultural areas of the San Luis Valley, south-central Colorado

    USGS Publications Warehouse

    Edelmann, Patrick; Buckles, D.R.

    1984-01-01

    The quality of ground water in the principal agricultural areas of the San Luis Valley, south-central Colorado was evaluated using chemical analyses of water collected from 57 wells completed in the unconfined aquifer and from 25 wells completed in the confined aquifer. Ground water in both aquifers generally contains dissolved-solids concentrations of less than 500 milligrams per liter. In most areas, calcium is the principal cation in the ground water. Nitrite plus nitrate concentrations expressed as nitrogen, are generally less than 1 milligram per liter. However, the quality of ground water in certain areas may pose health and agricultural hazards. Water in the unconfined aquifer near Center contains high nitrite plus nitrate as nitrogen concentrations. The highest measured concentration in this area was 33 milligrams per liter. Water containing more than 1 milligram per liter of nitrite as nitrogen, or 10 milligrams per liter nitrate, as nitrogen, poses a potential health hazard for infants and should not be used for drinking. In addition, dissolved-solids concentration in the ground water in some areas is greater than 500 milligrams per liter and, if used for irrigation may reduce crop yields. (USGS)

  9. Ecosystem Services Mapping for Sustainable Agricultural Water Management in California's Central Valley.

    PubMed

    Matios, Edward; Burney, Jennifer

    2017-02-24

    Accurate information on agricultural water needs and withdrawals at appropriate spatial and temporal scales remains a key limitation to joint water and land management decision-making. We use InVEST ecosystem service mapping to estimate water yield and water consumption as functions of land use in Fresno County, a key farming region in California's Central Valley. Our calculations show that in recent years (2010-2015), the total annual water yield for the county has varied dramatically from ∼0.97 to 5.37 km(3) (all ±17%; 1 MAF ≈ 1.233 km(3)), while total annual water consumption has changed over a smaller range, from ∼3.37 to ∼3.98 km(3) (±20%). Almost all of the county's water consumption (∼96% of total use) takes place in Fresno's croplands, with discrepancy between local annual surface water yields and crop needs met by surface water allocations from outside the county and, to a much greater extent, private groundwater irrigation. Our estimates thus bound the amount of groundwater needed to supplement consumption each year (∼1.76 km(3) on average). These results, combined with trends away from field crops and toward orchards and vineyards, suggest that Fresno's land and water management have become increasingly disconnected in recent years, with the harvested area being less available as an adaptive margin to hydrological stress.

  10. Stable isotope and groundwater flow dynamics of agricultural irrigation recharge into groundwater resources of the Central Valley, California

    SciTech Connect

    Davisson, M.L.; Criss, R.E.

    1995-01-01

    Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the {delta}{sup 18}O values of groundwater were relatively homogeneous (mostly -7.0 {+-} 0.5{per_thousand}), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high {sup 18}O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low {sup 18}O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in {delta}{sup 18}O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are {approximately}10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for {approximately}40 years, creating cones of depression {approximately}25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low {sup 18}O water (-11.0{per_thousand}) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp {sup 18}O gradients in our groundwater isotope map.

  11. Historic, Current, and Future Availability of Surface Water for Agricultural Groundwater Banking in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Kocis, T. N.; Dahlke, H. E.

    2015-12-01

    Groundwater banking, the intentional recharge of groundwater from surface water for storage and recovery, is an important conjunctive use strategy for water management in California. A largely unexplored approach to groundwater banking, agricultural groundwater banking (ag-GB), utilizes flood flows and agricultural lands for recharging groundwater. Understanding the availability of excess streamflow (e.g., the magnitude, frequency, timing, and duration of winter flood flows) is fundamental to assessing the feasibility of local-scale implementation of ag-GB. In this study, we estimate the current availability and forecast the future availability of winter (Nov to Apr) flood flows based on current and historic daily streamflow records for 200 stream gauges on tributaries to and streams within the Central Valley, California. For each gauge, we consider flows above a stationary 90th percentile as ideal for ag-GB because reservoir operations mitigate flood risk by releasing early winter flood flows. Results based on 70 years of data show that for 25% of the gauges there are significantly decreasing flow volumes above the 90th percentile and a decreasing number of days with flows above the 90th percentile. These flows, on average, make up 20% of the total annual winter flows. The majority of gauges further show, over the past 70 years, a decrease in total annual streamflow magnitude, a decrease in the magnitude of extreme flood events, and an increase in the frequency of flood events. Variations in winter flood flows due to climate change and climate variability are a challenge to water management in California. To aid the long-term forecast of streamflow conditions in California, we present a new water year type index for the Central Valley, which considers the variation in flow percentiles over time. Together, our results suggest that flexible, coordinated efforts for the local diversion of flood flows are needed to better utilize the increasingly rare winter flood

  12. The Central Valley Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Faunt, C.; Belitz, K.; Hanson, R. T.

    2009-12-01

    Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial

  13. 76 FR 18581 - Correction; Central Valley Project Improvement Act, Standard Criteria for Agricultural and Urban...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Agricultural and Urban Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of... Urban Water Management Plans. In the SUPPLEMENTARY INFORMATION section, the Web site in which to...

  14. Development of a complete Landsat evapotranspiration and energy balance archive to support agricultural consumptive water use reporting and prediction in the Central Valley, CA

    NASA Astrophysics Data System (ADS)

    Vitale, A.; Morton, C.; Huntington, J. L.; Melton, F. S.; Guzman, A.; McEvoy, D.

    2015-12-01

    Mapping evapotranspiration (ET) from agricultural areas in California's Central Valley is critical for understanding historical consumptive use of surface and groundwater. In addition, long histories of ET maps provide valuable training information for predictive studies of surface and groundwater demands. During times of drought, groundwater is commonly pumped to supplement reduced surface water supplies in the Central Valley. Due to the lack of extensive groundwater pumping records, mapping consumptive use using satellite imagery is an efficient and robust way for estimating agricultural consumptive use and assessing drought impacts. To this end, we have developed and implemented an algorithm for automated calibration of the METRIC remotely sensed surface energy balance model on NASA's Earth Exchange (NEX) to estimate ET at the field scale. Using automated calibration techniques on the NEX has allowed for the creation of spatially explicit historical ET estimates for the Landsat archive dating from 1984 to the near present. Further, our use of spatial NLDAS and CIMIS weather data, and spatial soil water balance simulations within the NEX METRIC workflow, has helped overcome challenges of time integration between satellite image dates. This historical and near present time archive of agricultural water consumption for the Central Valley will be an extremely useful dataset for water use and drought impact reporting, and predictive analyses of groundwater demands.

  15. Dimethyl Sulfide Emissions from Dairies and Agriculture as a Potential Contributor to Sulfate Aerosols in the California Central Valley

    NASA Astrophysics Data System (ADS)

    Lebel, E.; Marrero, J. E.; Bertram, T. H.; Blake, D. R.

    2014-12-01

    Whole air samples have been collected throughout Southern California during the previous five years of the NASA Student Airborne Research Program (SARP). During a flight over the Salton Sea in 2014, higher concentrations of dimethyl sulfide (DMS), a known marine emitted gas, were observed over neighboring agricultural land than over the sea itself. A comparison of DMS to methyl iodide, another known marine emitted gas, showed minimal correlation, revealing that DMS was being emitted from local sources. Ground samples at the Salton Sea verified that the DMS was not transported from the Pacific Ocean. Previous SARP studies have shown that DMS is emitted from dairies. The enhancements in ethanol (another dairy tracer) and DMS in several airborne samples collected south of the Salton Sea suggest dairy emissions of the observed DMS. DMS is a compound of interest because its oxidation can form cloud condensation nuclei. Based on data from all six SARP flights between 2009-2014, we propose that dairy and farming emissions of DMS in the San Joaquin Valley may be impacting aerosol loading in this region. A simple model that takes into account the particulate matter mass loadings was used to calculate the percent contribution of DMS to aerosol formation for the San Joaquin Valley.

  16. Recent landscape change in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Soulard, C. E.; Wilson, T. S.

    2012-12-01

    Long term monitoring of land use and land cover in California's intensively farmed Central Valley reveals several key physical and socioeconomic factors driving landscape change. As part of the USGS Land Cover Trends Project, we analyzed modern land-use/land-cover change for the California Central Valley ecoregion between 2000 and 2010, monitoring annual change between 2005 and 2010, while creating two new change intervals (2000-2005 and 2005-2010) to update the existing 27-year, interval-based analysis. Between 2000 and 2010, agricultural lands fluctuated due to changes in water allocations and emerging drought conditions, or were lost permanently to development (240 square km). Land-use pressure from agriculture and development also led to a decline in grasslands and shrublands across the region (280 square km). Overall, 400 square km of new developed lands were added in the first decade of the 21st century. From 2007 to 2010, development only expanded by 50 square km, coinciding with defaults in the banking system, the onset of historic foreclosure crisis in California and the global economic downturn. Our annual LULC change estimates capture landscape-level change in response to regional policy changes, climate, and fluctuations (e.g., growth or decline) in the national and global economy. The resulting change data provide insights into the drivers of landscape change in the California Central Valley and the combination of two consistent mapping efforts represents the first continuous, 37-year endeavor of its kind.

  17. Biological Assessment of Urban and Agricultural Streams in the California Central Valley (Fall 2002 Through Spring 2004)

    NASA Astrophysics Data System (ADS)

    Bacey, J.; Moncada, A.

    2005-05-01

    California has over 200,000 miles of rivers and streams that are increasingly impacted from human activities. Various agencies in the state have begun to conduct bioassessment to evaluate these impacts. We conducted a pilot study to assess potential aquatic impacts of pesticides and other human activities in two urban creeks and two agricultural creeks in the fall and spring for two years (2002-04) using a modified U.S. EPA EMAP method. All creeks showed highly impacted conditions. Water quality measurements indicated below normal dissolved oxygen levels at 44% and 15% of the sites, and elevated temperatures at 70% and 73% of the urban and agricultural sites, respectively. Physical habitat scores indicated significant impacts. Diazinon and chlorpyrifos were detected at all sites (trace to 0.212 ppb). Pyrethroids were detected in water and sediment in urban sites only (trace to 27.5 ppt). High numbers of chironomidae and very low numbers of pollution intolerant species were detected in the benthic macroinvertebrate community. Urban creeks had a higher number of pollution tolerant species compared to agricultural creeks. All sites were ecologically impacted. Mulitvariate ANOVA of macroinvertebrate metrics revealed a significant difference between urban and agricultural sites (P= 0.002) and between fall and spring seasons (P=0.036).

  18. Characterization of LANDSAT-4 TM and MSS Image Quality for the Interpretation of California's Agricultural Resources. [Central Valley

    NASA Technical Reports Server (NTRS)

    Degloria, S. D.; Colwell, R. N.

    1985-01-01

    The quality of LANDSAT-4 MSS and TM data was determined by analyzing TM spectral and spatial performance in terms of spectral variability of natural targets and the TM-ground instantaneous field-of-view (IFOV) variability in level and mountainous terrain; and by assessing the suitability of TM and MSS image products for characterizing renewable resourse features. The TM data should be extremelly valuable for crop type and area proportion estimation; undating agricultural land use survey maps at 1:24,000 scale and smaller, field boundary definition; and determining the size and location of individual farmsteads. Ongoing research activities are focused on making spectral and spatial analyses of both MSS and TM analytical film products. The improved spectral, spatial, and radiometric quality of the TM data, should promote a renewed emphasis and interest in direct visual interpretation of these image products, both for updating and improving land stratification in support of resource inventory and for enhancing the image analyst's contribution to computer-assisted analysis procedures.

  19. Groundwater Availability of the Central Valley Aquifer, California

    USGS Publications Warehouse

    Faunt, Claudia C.

    2009-01-01

    California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

  20. Water availability and subsidence in California's Central Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Sneed, Michelle

    2015-01-01

    California’s Central Valley covers about 52,000 square kilometers (km2) and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the broad alluvial filled structural trough, with an estimated value exceeding $20 billion per year (Faunt 2009) (Figure 1). Central Valley agriculture depends on state and federal water systems that divert surface water, predominantly originating from Sierra Nevada snowmelt, to agricultural fields. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture, as it grew, developed a reliance on groundwater for irrigation.

  1. Climate change and agricultural transformation in the Oaxaca Valley, Mexico

    SciTech Connect

    Dilley, F.B.

    1993-01-01

    The Valley of Oaxaca, a semi-arid region in the central highlands of southern Mexico, provides a case study through which to develop a methodology for climate change impact assessment. The causes and impacts of climate change originate in dialectic processes within a nexus of inter-dependent social, technical, environmental, cultural and academic production relations. Agriculture is the most important economic activity in the Valley, and rain-fed maize the most important crop. Harvest failures from droughts occur one year in four. Annual rainfall varies with large-scale convection of water vapor transported from the Pacific and Gulf of Mexico during summer, upper-air disturbances caused by hurricanes and El Ninos. Variations in maize yields and losses have roughly moisture availability during August. Yields and losses can be predicted using precipitation during this time, or directly from atmospheric circulation. Contemporary agriculture in the Valley of Oaxaca has both traditional and modern sectors, of which both may appear within individual communities and households. The traditional sector consists of semi-autonomous rural communities using traditional technology for subsistence farming. The modern sector uses tractors, irrigation pumps, agricultural chemicals and hybrid seeds to produce cash crops and dairy products. The evidence for climate change in the Valley is ambiguous and contradictory. Under wet or dry scenarios, climate change affects the rate and pathway of the absorption of Oaxaca's traditional rural communities into the wage labor market of the larger capitalist system. Increased moisture availability would raise land productivity, promoting cash cropping and development of the modern market-oriented agricultural sector and leading to land consolidation and rural-to-urban migration. Decreased moisture availability would inhibit cash-cropping but also lead to rural-to-urban migration due to decreased land productivity.

  2. Increased body mass of ducks wintering in California's Central Valley

    USGS Publications Warehouse

    Fleskes, Joseph P.; Yee, Julie L.; Yarris, Gregory S.; Loughman, Daniel L.

    2016-01-01

    Waterfowl managers lack the information needed to fully evaluate the biological effects of their habitat conservation programs. We studied body condition of dabbling ducks shot by hunters at public hunting areas throughout the Central Valley of California during 2006–2008 compared with condition of ducks from 1979 to 1993. These time periods coincide with habitat increases due to Central Valley Joint Venture conservation programs and changing agricultural practices; we modeled to ascertain whether body condition differed among waterfowl during these periods. Three dataset comparisons indicate that dabbling duck body mass was greater in 2006–2008 than earlier years and the increase was greater in the Sacramento Valley and Suisun Marsh than in the San Joaquin Valley, differed among species (mallard [Anas platyrhynchos], northern pintail [Anas acuta], America wigeon [Anas americana], green-winged teal [Anas crecca], and northern shoveler [Anas clypeata]), and was greater in ducks harvested late in the season. Change in body mass also varied by age–sex cohort and month for all 5 species and by September–January rainfall for all except green-winged teal. The random effect of year nested in period, and sometimes interacting with other factors, improved models in many cases. Results indicate that improved habitat conditions in the Central Valley have resulted in increased winter body mass of dabbling ducks, especially those that feed primarily on seeds, and this increase was greater in regions where area of post-harvest flooding of rice and other crops, and wetland area, has increased. Conservation programs that continue to promote post-harvest flooding and other agricultural practices that benefit wintering waterfowl and continue to restore and conserve wetlands would likely help maintain body condition of wintering dabbling ducks in the Central Valley of California.

  3. Effects of Groundwater Development on Uranium: Central Valley, California, USA

    USGS Publications Warehouse

    Jurgens, Bryant C.; Fram, Miranda S.; Belitz, Kenneth; Burow, Karen R.; Landon, Matthew K.

    2009-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential longterm effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.

  4. Effects of groundwater development on uranium: Central Valley, California, USA.

    PubMed

    Jurgens, Bryant C; Fram, Miranda S; Belitz, Kenneth; Burow, Karen R; Landon, Matthew K

    2010-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco(2) concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.

  5. Winter habitat associations of diurnal raptors in Californias Central Valley

    USGS Publications Warehouse

    Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

    2011-01-01

    The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

  6. Effects of Groundwater Development on Uranium: Central Valley, California, USA

    USGS Publications Warehouse

    Jurgens, B.C.; Fram, M.S.; Belitz, K.; Burow, K.R.; Landon, M.K.

    2010-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world. Journal compilation ?? 2009 National Ground Water Association. No claim to original US government works.

  7. Evapotranspiration of applied water, Central Valley, California, 1957-78

    USGS Publications Warehouse

    Williamson, Alex K.

    1982-01-01

    In the Central Valley, Calif., where 57% of the 20,000 square miles of land is irrigated, ground-water recharge from agricultural lands is an important input to digital simulation models of ground-water flow. Several methods of calculating recharge were explored for the Central Valley Aquifer Project and a simplified water budget was designed where net recharge (recharge minus pumpage) equals net surface water diverted minus evapotranspiration of applied water (ETAW). This equation eliminates the need to determine pumpage from the water-table aquifer, assuming that the time lag for infiltration is not longer than the time intervals of interest for modeling. This study evaluates only the evapotranspiration of applied water. Future reports will describe the other components of the water budget. ETAW was calculated by summing the products of ETAW coefficients and respective crop areas for each 7 1/2-minute quadrangle area in the valley, for each of three land-use surveys between 1957 and 1978. In 1975 total ETAW was 15.2 million acre-feet, a 43% increase since 1959. The largest increases were in the south, especially Kern County, which had a sixfold increase, which was caused by the import of surface water in the California Aqueduct. (USGS)

  8. Agricultural Development, Land Change, and Livelihoods in Tanzania's Kilombero Valley

    NASA Astrophysics Data System (ADS)

    Connors, John Patrick

    The Kilombero Valley lies at the intersection of a network of protected areas that cross Tanzania. The wetlands and woodlands of the Valley, as well as the forest of surrounding mountains are abundant in biodiversity and are considered to be critical areas for conservation. This area, however, is also the home to more than a half million people, primarily poor smallholder farmers. In an effort to support the livelihoods and food security of these farmers and the larger Tanzanian population, the country has recently targeted a series of programs to increase agricultural production in the Kilombero Valley and elsewhere in the country. Bridging concepts and methods from land change science, political ecology, and sustainable livelihoods, I present an integrated assessment of the linkages between development and conservation efforts in the Kilombero Valley and the implications for food security. This dissertation uses three empirical studies to understand the process of development in the Kilombero Valley and to link the priorities and perceptions of conservation and development efforts to the material outcomes in food security and land change. The first paper of this dissertation examines the changes in land use in the Kilombero Valley between 1997 and 2014 following the privatization of agriculture and the expansion of Tanzania's Kilimo Kwanza program. Remote sensing analysis reveals a two-fold increase in agricultural area during this short time, largely at the expense of forest. Protected areas in some parts of the Valley appear to be deterring deforestation, but rapid agricultural growth, particularly surrounding a commercial rice plantation, has led to loss of extant forest and sustained habitat fragmentation. The second paper focuses examines livelihood strategies in the Valley and claims regarding the role of agrobiodiversity in food security. The results of household survey reveal no difference or lower food security among households that diversify their

  9. California's Central Valley Groundwater Study: A Powerful New Tool to Assess Water Resources in California's Central Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Hanson, Randall T.; Belitz, Kenneth; Rogers, Laurel

    2009-01-01

    Competition for water resources is growing throughout California, particularly in the Central Valley. Since 1980, the Central Valley's population has nearly doubled to 3.8 million people. It is expected to increase to 6 million by 2020. Statewide population growth, anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta have created an intense demand for water. Tools and information can be used to help manage the Central Valley aquifer system, an important State and national resource.

  10. 27 CFR 9.49 - Central Delaware Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Delaware Valley.” (b) Approved maps. The appropriate maps for determining the boundaries of the Central... generally westward along Sanford Road to its intersection with Route 519 about one mile north of...

  11. ANALYSIS OF LOTIC MACROINVERTEBRATE ASSEMBLAGES IN CALIFORNIA'S CENTRAL VALLEY

    EPA Science Inventory

    Using multivariate and cluster analyses, we examined the relaitonships between chemical and physical characteristics and macroinvertebrate assemblages at sites sampled by R-EMAP in California's Central Valley. By contrasting results where community structure was summarized as met...

  12. Sustainability of irrigated agriculture in the San Joaquin Valley, California.

    PubMed

    Schoups, Gerrit; Hopmans, Jan W; Young, Chuck A; Vrugt, Jasper A; Wallender, Wesley W; Tanji, Ken K; Panday, Sorab

    2005-10-25

    The sustainability of irrigated agriculture in many arid and semiarid areas of the world is at risk because of a combination of several interrelated factors, including lack of fresh water, lack of drainage, the presence of high water tables, and salinization of soil and groundwater resources. Nowhere in the United States are these issues more apparent than in the San Joaquin Valley of California. A solid understanding of salinization processes at regional spatial and decadal time scales is required to evaluate the sustainability of irrigated agriculture. A hydro-salinity model was developed to integrate subsurface hydrology with reactive salt transport for a 1,400-km(2) study area in the San Joaquin Valley. The model was used to reconstruct historical changes in salt storage by irrigated agriculture over the past 60 years. We show that patterns in soil and groundwater salinity were caused by spatial variations in soil hydrology, the change from local groundwater to snowmelt water as the main irrigation water supply, and by occasional droughts. Gypsum dissolution was a critical component of the regional salt balance. Although results show that the total salt input and output were about equal for the past 20 years, the model also predicts salinization of the deeper aquifers, thereby questioning the sustainability of irrigated agriculture.

  13. Solar Energy within the Central Valley, CA: Current Practices and Potential

    NASA Astrophysics Data System (ADS)

    Hoffacker, M. K.; Hernandez, R. R.; Allen, M. F.

    2015-12-01

    Utility-scale solar energy (USSE, ≥ 1 megawatt [MW]) systems are rapidly being deployed in the Central Valley of California, generating clean electricity and new job opportunities. Utility-scale solar energy systems require substantial quantities of land or space, often prompting an evaluation of environmental impacts and trade-offs when selecting their placement. Utilizing salt-contaminated agricultural land (as the sodium absorption and electrical conductivity values are unsuitably high), unsuitable for food production, and lands within the built environment (developed), can serve as a co-benefit opportunity when reclamation of these lands for USSE development is prioritized. In this study, we quantify the theoretical and generation-based solar energy potential for the Central Valley according to land-cover type, crop type, and for salt-contaminated lands. Further, we utilize the Carnegie Energy and Environmental Compatibility (CEEC) model to identify and prioritize solar energy, integrating environmental resource opportunities and constraints most relevant to the Central Valley. We use the CEEC model to generate a value-based environmental compatibility output for the Central Valley. The Central Valley extends across nearly 60,000 km2 of California with the potential of generating 21,800 - 30,300 TWh y-1 and 41,600 TWh y-1 of solar energy for photovoltaic (PV) and concentrating solar power (CSP), respectively. Pasture, hay, and cultivated crops comprise over half of the Central Valley, much of which is considered prime agriculture or of statewide or local importance for farming (28,200 km2). Together, approximately one-third of this region is salt-contaminated (16%) or developed (11%). This confers a generation-based potential of 5713 - 7891 TWh y-1 and 2770 TWh y-1 for PV and CSP, respectively. As energy, food, and land are inextricably linked, our study shows how land favorable for renewable energy systems can be used more effectively in places where land is

  14. Emission rates of organics from vegetation in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Winer, Arthur M.; Arey, Janet; Atkinson, Roger; Aschmann, Sara M.; Long, William D.; Morrison, C. Lynn; Olszyk, David M.

    Rates of emission of speciated hydrocarbons have been determined for more than 30 of the most dominant (based on acreage) agricultural and natural plant types found in California's Central Valley. These measurements employed flow-through Teflon chambers, sample collection on solid adsorbent and thermal desorption gas chromatography (GC) and GC-mass spectrometry analysis to identify more than 40 individual organic compounds. In addition to isoprene and the monoterpenes, we observed sesquiterpenes, alcohols, acetates, aldehydes, ketones, ethers, esters, alkanes, alkenes and aromatics as emissions from these plant species. Mean emission rates for total monoterpenes ranged from none detected in the case of beans, grapes, rice and wheat, to as high as 12-30 μg h -1 g -1 for pistachio and tomato (normalized to dry leaf and total biomass, respectively). Other agricultural species exhibiting substantial rates of emission of monoterpenes included carrot, cotton, lemon, orange and walnut. All of the plant species studied showed total assigned compound emission rates in the range between 0.1 and 36 νg h -1 g -1.

  15. Characterization of the Mid Summer Drought in the Central Valley of Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Alfaro, E.

    2013-05-01

    The IAS region is characterized by climate features of unique nature, one of them is the Mid-Summer Drought (MSD) or "veranillo", an atmospheric feature rarely observed in other tropical regions. On the Pacific slope of Central America, the precipitation annual cycle is characterized by two rainfall maxima in June and September-October, an extended dry season from November to May, and a secondary precipitation minima during July-August (MSD). Three daily gauge stations records, e.g. La Argentina, Fabio Baudrit and Juan Santamaria, located in the Central Valley of Costa Rica were studied to characterize the MSD from 1937 to 2010. Among the aspects considered are the MSD duration, intensity, timing and seasonal predictability. The modulation of these aspects by climate variability sources as Equatorial Eastern Pacific and Tropical North Atlantic was lately explored, including their interannual and decadal variability. The MSD signal strongly impact social and economic life in the region like energy and the agriculture sector. Additionally, the Central Valley of Costa Rica hosts most of the Costa Rican population with the higher level of exposure and vulnerability to hydro-meteorological hazards.

  16. Groundwater Quality in the Central Eastside San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, Kenneth; Landon, Matthew K.

    2010-01-01

    The Central Eastside study unit is located in California's San Joaquin Valley. The 1,695 square mile study unit includes three groundwater subbasins: Modesto, Turlock, and Merced (California Department of Water Resources, 2003). The primary water-bearing units consist of discontinuous lenses of gravel, sand, silt, and clay, which are derived largely from the Sierra Nevada Mountains to the east. Public-supply wells provide most of the drinking water supply in the Central Eastside. Consequently, the primary aquifer in the Central Eastside study unit is defined as that part of the aquifer corresponding to the perforated interval of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 350 feet, consist of solid casing from the land surface to a depth of about 100 to 200 feet, and they are perforated below the solid casing. Water quality in the shallower and deeper parts of the aquifer system may differ from that in the primary aquifer. The Central Eastside study unit has hot and dry summers and cool, moist, winters. Average annual rainfall ranges from 11 to 15 inches. The Stanislaus, Tuolumne, and Merced Rivers, with headwaters in the Sierra Nevada Mountains, are the primary streams traversing the study unit. Land use in the study unit is approximately 59 percent (%) agricultural, 34% natural (primarily grassland), and 7% urban. The primary crops are almonds, walnuts, peaches, grapes, grain, corn, and alfalfa. The largest urban areas (2003 population in parentheses) are the cities of Modesto (206,872), Turlock (63,467), and Merced (69,512). Municipal water use accounts for about 5% of the total water use in the Central Eastside study unit, with the remainder used for irrigated agriculture. Groundwater accounts for about 75% of the municipal supply, and surface water accounts for about 25%. Recharge to the groundwater flow system is primarily from percolation of irrigation return

  17. Land use investigations in the central valley and central coastal test sites, California

    NASA Technical Reports Server (NTRS)

    Estes, J. E.

    1973-01-01

    The Geography Remote Sensing Unit (GRSU) at the University of California, Santa Barbara is responsible for investigations with ERTS-1 data in the Central Coastal Zone and West Side of the San Joaquin Valley. The nature of investigative effort involves the inventory, monitoring, and assessment of the natural and cultural resources of the two areas. Land use, agriculture, vegetation, landforms, geology, and hydrology are the principal subjects for attention. These parameters are the key indicators of the dynamically changing character of the areas. Monitoring of these parameters with ERTS-1 data will provide the techniques and methodologies required to generate the information needed by federal, state, county, and local agencies to assess change-related phenomena and plan for management and development.

  18. Water availability and land subsidence in the Central Valley, California, USA

    USGS Publications Warehouse

    Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

    2016-01-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  19. Water availability and land subsidence in the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

    2016-05-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  20. Gravity survey of Dixie Valley, west-central Nevada

    USGS Publications Warehouse

    Schaefer, Donald H.

    1983-01-01

    Dixie Valley, a northeast-trending structural trough typical of valleys in the Basin and Range Province, is filled with a maximum of about 10,000 feet of alluvial and lacustrine deposits , as estimated from residual-gravity measurements obtained in this study. On the basis of gravity measurements at 300 stations on nine east-west profiles, the gravity residuals reach a maximum of 30 milligals near the south-central part of the valley. Results from a three-dimensional inversion model indicate that the central depression of the valley is offset to the west of the geographic axis. This offset is probably due to major faulting along the west side of the valley adjacent to the Stillwater Range. Comparison of depths to bedrock obtained during this study and depths obtained from a previous seismic-refraction study indicates a reasonably good correlation. A heterogeneous distribution of densities within the valley-fill deposits would account for differing depths determined by the two methods. (USGS)

  1. Irrigation in California's Central Valley Strengthens the Southwestern U. S. Monsoon

    NASA Astrophysics Data System (ADS)

    Lo, M.; Famiglietti, J. S.

    2011-12-01

    Agricultural irrigation in the Central Valley of California has always depended on surface water reservoirs and groundwater pumping. This anthropogenic redistribution of water modifies the land hydrological cycle significantly, especially by increasing evapotranspiration. In this study we establish the importance of California's Central Valley irrigation in the local and regional hydrological cycles, including its role in land surface-atmosphere interactions. We use the global, NCAR Community Atmosphere Model, with realistic estimates of irrigation applied to the NCAR Community Land Model. Consistent with previous studies, we find that irrigation modifies the surface radiation budget by generally increasing latent heat, decreasing sensible heat and decreasing land surface temperature. Although atmospheric water vapor increases due to enhanced evapotranspiration, during the summer, the Central Valley underlies the descending branch of the large-scale circulation, which inhibits the occurrence of convection. Consequently, Central Valley irrigation has negligible effects on local precipitation. However, precipitation in the downwind region of California, i.e., in the southwestern U. S., increases, enhancing the North American Monsoon, while forming a regional, anthropogenic recycling loop in the hydrologic cycle which returns water to California. This study has implications for the importance of human-driven impacts on the hydrological cycle and local and regional climate, and for water resources management in California and the Western United States.

  2. Student and School Indicators for Youth in California's Central Valley

    ERIC Educational Resources Information Center

    Danenberg, Anne; Jepsen, Christopher; Cerdan, Pedro

    2002-01-01

    Twenty percent of California's public-school students attend schools in the Central Valley. Many of these students are at risk of poor educational outcomes: One-quarter of the children in grades K-5 do not speak English or do not speak it well; one-half of all K-12 students participate in a subsidized lunch program. This sourcebook provides a…

  3. 27 CFR 9.49 - Central Delaware Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Central Delaware Valley. 9.49 Section 9.49 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU.... (ix) From there northward along Covered Bridge Road to Green Sergeant Covered Bridge. (x) From...

  4. 27 CFR 9.49 - Central Delaware Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Central Delaware Valley. 9.49 Section 9.49 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas §...

  5. 27 CFR 9.49 - Central Delaware Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Central Delaware Valley. 9.49 Section 9.49 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas §...

  6. Underground water in Sanpete and central Sevier valleys, Utah

    USGS Publications Warehouse

    Richardson, George Burr

    1907-01-01

    Sanpete and central Sevier valleys are situated at the border of the Basin Range and Plateau provinces in south-central Utah. They are bounded on the east by the Wasatch and Sevier plateaus and on the west by the Gunnison Plateau and the Valley and Pavant ranges, and are drained by Sevier River, which empties into Sevier Lake in the Great Basin. (See fig. 1, p. 6.)These valleys rank with the richest parts of the State. They were occupied a few years after the Mormon pioneers founded Salt Lake City, in 1847, when settlements, which soon became thriving farming communities, were established where water for irrigation was most available. A variety of crops, especially wheat, are successfully grown, and the valleys are popularly known as the "granary of Utah." Sheep raising is also an important industry, the adjacent highlands being used for summer pastures. The climate is arid, and there is a striking contrast between those areas which in their natural state are covered with sagebrush and grease wood and the fruitful cultivated tracts. (See PI. I, A and B.) Trees are normally absent in the valleys, but they flourish to a limited extent on the adjacent highlands, where there are thin growths of quaking aspen, scrub oak, and stunted conifers. Irrigation is necessary for the production of crops. Canal systems are maintained by San Pitch Creek and Sevier River, and the mountain streams are tapped by ditches near the mouths of the canyons, but this supply is insufficient and attention is being turned to the subterranean store.This report is a preliminary statement of the general conditions of occurrence of underground water in Sanpete and central Sevier valleys. The field work was carried on in cooperation with Sanpete and Sevier counties through the State engineer, Mr. Caleb Tanner, who detailed Mr. C. S. Jarvis to collect the data embodied in the list of springs and wells on pages 51-60.

  7. Drought, Land-Use Change, and Water Availability in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Faunt, C. C.; Sneed, M.; Traum, J.

    2015-12-01

    The Central Valley is a broad alluvial-filled structural trough that covers about 52,000 square kilometers and is one of the most productive agricultural regions in the world. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture developed a reliance on groundwater for irrigation. During recent drought periods (2007-09 and 2012-present), groundwater pumping has increased due to a combination of factors including drought and land-use changes. In response, groundwater levels have declined to levels approaching or below historical low levels. In the San Joaquin Valley, the southern two thirds of the Central Valley, the extensive groundwater pumpage has caused aquifer system compaction, resulting in land subsidence and permanent loss of groundwater storage capacity. The magnitude and rate of subsidence varies based on geologic materials, consolidation history, and historical water levels. Spatially-variable subsidence has changed the land-surface slope, causing operational, maintenance, and construction-design problems for surface-water infrastructure. It is important for water agencies to plan for the effects of continued water-level declines, storage losses, and/or land subsidence. To combat these effects, excess surface water, when available, is artificially recharged. As surface-water availability, land use, and artificial recharge continue to vary, long-term groundwater-level and land-subsidence monitoring and modelling are critical to understanding the dynamics of the aquifer system. Modeling tools, such as the Central Valley Hydrologic Model, can be used in the analysis and evaluation of management strategies to mitigate adverse impacts due to subsidence, while also optimizing water availability. These analyses will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  8. Impact of Air Pollution on California Central Valley Fog Frequency

    NASA Astrophysics Data System (ADS)

    Gray, E.; Baldocchi, D. D.; Goldstein, A. H.

    2015-12-01

    Throughout the 20th century, trends in California Central Valley fog frequency have changed dramatically without explanation. While episodes of dense radiation fog, known regionally as Tule Fog, increased steadily from 1930-1970, analysis from both ground and remote sensing measurements confirm a 46-50% reduction in fog days in the last 30 years (Baldocchi and Waller, 2014, Herkes et al., 2014). The dominant hypotheses suggest that the recent decline in radiation fog can be explained by the rising temperatures associated with climate change or urban heat island effect. This assertion fails to explain the significant increase in Central Valley fog midcentury. Here we instead assert that changes in air pollution, rather than climate, better support this upward then downward temporal trend. Automobile use greatly increased emissions of nitrogen oxide (NOx) midcentury, followed by a large decrease in vehicle emissions due to statewide regulation from 1980 to present. In the Central Valley, NOx from automobile emissions contributes to the formation ammonium nitrate (NH4NO3), the dominant hygroscopic aerosol in the valley's wintertime boundary layer that can act as cloud condensation nuclei (CCN) necessary for fog droplet formation. Thus, changes in air pollution not only affect the number of CCN, but may also impact the density and persistence of fog episodes. Using NOAA meteorological records throughout the twentieth century, we will show the correlation between fog frequency, air pollution, and climatic drivers. We conclude that fog trends are closely correlated with changes in air pollution, rather than solely climate change.

  9. Field Scale Groundwater Nitrate Loading Model for the Central Valley, California, 1945-Current

    NASA Astrophysics Data System (ADS)

    Harter, T.; Dzurella, K.; Bell, A.; Kourakos, G.

    2015-12-01

    Anthropogenic groundwater nitrate contamination in the Central Valley aquifer system, California, is widespread, with over 40% of domestic wells in some counties exceeding drinking water standards. Sources of groundwater nitrate include leaky municipal wastewater systems, municipal wastewater recharge, onsite wastewater treatment (septic) systems, atmospheric nitrogen deposition, animal farming, application of organic waste materials (sludge, biosolids, animal manure) to agricultural lands, and synthetic fertilizer. At the site or field scale, nitrogen inputs to the landscape are balanced by plant nitrogen uptake and harvest, atmospheric nitrogen losses, surface runoff of nitrogen, soil nitrogen storage changes, and leaching to groundwater. Irrigated agriculture is a dominant player in the Central Valley nitrogen cycle: The largest nitrogen fluxes are synthetic fertilizer and animal manure applications to cropland, crop nitrogen uptake, and groundwater nitrogen losses. We construct a historic field/parcel scale groundwater nitrogen loading model distinguishing urban and residential areas, individual animal farming areas, leaky wastewater lagoons, and approximately 50 different categories of agricultural crops. For non-agricultural landuses, groundwater nitrate loading is based on reported leaching values, animal population, and human population. For cropland, groundwater nitrate loading is computed from mass balance, taking into account diverse and historically changing management practices between different crops. Groundwater nitrate loading is estimated for 1945 to current. Significant increases in groundwater nitrate loading are associated with the expansion of synthetic fertilizer use in the 1950s to 1970s. Nitrate loading from synthetic fertilizer use has stagnated over the past 20 years due to improvements in nutrient use efficiency. However, an unbroken 60 year exponential increase in dairy production until the late 2000s has significantly impacted the

  10. Spatially Distributed Exposure Assessment of Pesticide Sources in the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Zhang, M.

    2009-12-01

    Pesticides in agricultural runoff are considered as significant pollution from nonpoint sources in intensive agricultural regions such as California’s Central Valley. This study presents a spatially explicit modeling approach to extend field-scale pesticide transport model into basin level. The approach was applied to simulate chlorpyrifos use in the Central Valley during 2003-2007. Chlorpyrifos loadings were reported for each section (1×1 mi cell), and the simulation results were in general agreements with monitoring results at watershed level. The average value of loading as percent of use (LAPU) is 0.031% and varied with seasons and locations. Results of this study provide strong evidence that surface runoff generation and pesticide application timing are the two influencing factors on the spatial and temporal variability of chlorpyrifos sources from agricultural fields. This is one of the first studies in coupling GIS and field-scale models and providing simulations for the dynamics of pesticides over an agriculturally dominated landscape. The demonstrated modeling approach may be useful for assessment of the implementations of best management practice (BMPs) and total maximum daily load (TMDL).

  11. Integrated Economic Modeling of Water Supply-Quality Tradeoffs: An Application to the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Bair, L.; MacEwan, D.

    2015-12-01

    Sustainable water management in the San Joaquin Valley, California involves the complex interaction of agricultural, municipal and industrial, and environmental water use. California's Sustainable Groundwater Management Act (SGMA) of 2014 requires groundwater basins historically in a state of overdraft to bring the basin into a sustainable balance over the next 20 years. In addition to limiting groundwater availability, implementation of the SGMA has implications for surface and groundwater quality. Availability of groundwater influences agricultural production decisions, resulting in variation in agricultural runoff and changes to surface and groundwater quality. Changes in water quality have economic impacts on agricultural production and urban water use. These impacts range from reductions in crop productivity to costs of alternative water supplies to amend declining water quality. We model the impact of agricultural and urban groundwater availability on surface water quality within the San Joaquin and Kings River watersheds in the Central Valley, downriver to the Mendota Pool by linking SWAT (Soil and Water Assessment Tool), an integrated water supply-quality model, with SWAP (Statewide Agricultural Production Model), a regional agricultural economics model. The integrated model specifies the relationship between changes in groundwater availability, groundwater elevation, agricultural production, and surface water quality. We link the SWAT-SWAP model output to urban and agricultural economic loss calculations that are a function of water quality. Model results demonstrate the economic tradeoffs between groundwater availability and water quality. The results of the integrated economic water supply-quality model are applicable to other regions in California and elsewhere that contain complex water supply-quality interactions.

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

    USGS Publications Warehouse

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

    1969-01-01

    remainder of the valley is drained by the Rio Grande and its tributaries. The climate of the San Luis Valley is arid, and a successful agricultural economy would not be possible without irrigation. It is characterized by cold winters, moderate summers, and much sunshine. The average annual precipitation on the valley floor ranges from 7 to 10 inches. More than half the precipitation occurs from July to September. Moisture deficiency in the valley is shown by the graph comparing pan evaporation and precipitation {fig. 3}. For the years 1961-67 average pan evaporation for the period April through September was 52.25 inches, but average precipitation for the period was only 5.02 inches. Average annual precipitation was 7.8 inches. Owing to the short growing season (90-120 days), crops a.re restricted mainly to barley, oats, potatoes, and other vegetables.

  13. Modeling the long-term fate of agricultural nitrate in groundwater in the San Joaquin Valley, California

    USGS Publications Warehouse

    Chapelle, Francis H.; Campbell, Bruce G.; Widdowson, Mark A.; Landon, Mathew K.

    2013-01-01

    Nitrate contamination of groundwater systems used for human water supplies is a major environmental problem in many parts of the world. Fertilizers containing a variety of reduced nitrogen compounds are commonly added to soils to increase agricultural yields. But the amount of nitrogen added during fertilization typically exceeds the amount of nitrogen taken up by crops. Oxidation of reduced nitrogen compounds present in residual fertilizers can produce substantial amounts of nitrate which can be transported to the underlying water table. Because nitrate concentrations exceeding 10 mg/L in drinking water can have a variety of deleterious effects for humans, agriculturally derived nitrate contamination of groundwater can be a serious public health issue. The Central Valley aquifer of California accounts for 13 percent of all the groundwater withdrawals in the United States. The Central Valley, which includes the San Joaquin Valley, is one of the most productive agricultural areas in the world and much of this groundwater is used for crop irrigation. However, rapid urbanization has led to increasing groundwater withdrawals for municipal public water supplies. That, in turn, has led to concern about how contaminants associated with agricultural practices will affect the chemical quality of groundwater in the San Joaquin Valley. Crop fertilization with various forms of nitrogen-containing compounds can greatly increase agricultural yields. However, leaching of nitrate from soils due to irrigation has led to substantial nitrate contamination of shallow groundwater. That shallow nitrate-contaminated groundwater has been moving deeper into the Central Valley aquifer since the 1960s. Denitrification can be an important process limiting the mobility of nitrate in groundwater systems. However, substantial denitrification requires adequate sources of electron donors in order to drive the process. In many cases, dissolved organic carbon (DOC) and particulate organic carbon

  14. A Comparison of Groundwater Storage Using GRACE Data, Groundwater Levels, and a Hydrological Model in Californias Central Valley

    NASA Technical Reports Server (NTRS)

    Kuss, Amber; Brandt, William; Randall, Joshua; Floyd, Bridget; Bourai, Abdelwahab; Newcomer, Michelle; Skiles, Joseph; Schmidt, Cindy

    2011-01-01

    The Gravity Recovery and Climate Experiment (GRACE) measures changes in total water storage (TWS) remotely, and may provide additional insight to the use of well-based data in California's agriculturally productive Central Valley region. Under current California law, well owners are not required to report groundwater extraction rates, making estimation of total groundwater extraction difficult. As a result, other groundwater change detection techniques may prove useful. From October 2002 to September 2009, GRACE was used to map changes in TWS for the three hydrological regions (the Sacramento River Basin, the San Joaquin River Basin, and the Tulare Lake Basin) encompassing the Central Valley aquifer. Net groundwater storage changes were calculated from the changes in TWS for each of the three hydrological regions and by incorporating estimates for additional components of the hydrological budget including precipitation, evapotranspiration, soil moisture, snow pack, and surface water storage. The calculated changes in groundwater storage were then compared to simulated values from the California Department of Water Resource's Central Valley Groundwater- Surface Water Simulation Model (C2VSIM) and their Water Data Library (WDL) Geographic Information System (GIS) change in storage tool. The results from the three methods were compared. Downscaling GRACE data into the 21 smaller Central Valley sub-regions included in C2VSIM was also evaluated. This work has the potential to improve California's groundwater resource management and use of existing hydrological models for the Central Valley.

  15. Efficient crop type mapping based on remote sensing in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Zhong, Liheng

    Most agricultural systems in California's Central Valley are purposely flexible and intentionally designed to meet the demands of dynamic markets. Agricultural land use is also impacted by climate change and urban development. As a result, crops change annually and semiannually, which makes estimating agricultural water use difficult, especially given the existing method by which agricultural land use is identified and mapped. A minor portion of agricultural land is surveyed annually for land-use type, and every 5 to 8 years the entire valley is completely evaluated. So far no effort has been made to effectively and efficiently identify specific crop types on an annual basis in this area. The potential of satellite imagery to map agricultural land cover and estimate water usage in the Central Valley is explored. Efforts are made to minimize the cost and reduce the time of production during the mapping process. The land use change analysis shows that a remote sensing based mapping method is the only means to map the frequent change of major crop types. The traditional maximum likelihood classification approach is first utilized to map crop types to test the classification capacity of existing algorithms. High accuracy is achieved with sufficient ground truth data for training, and crop maps of moderate quality can be timely produced to facilitate a near-real-time water use estimate. However, the large set of ground truth data required by this method results in high costs in data collection. It is difficult to reduce the cost because a trained classification algorithm is not transferable between different years or different regions. A phenology based classification (PBC) approach is developed which extracts phenological metrics from annual vegetation index profiles and identifies crop types based on these metrics using decision trees. According to the comparison with traditional maximum likelihood classification, this phenology-based approach shows great advantages

  16. Analysis of gravity data in Central Valleys, Oaxaca, southern, Mexico

    NASA Astrophysics Data System (ADS)

    Gonzalez, T.; Ferrusquia, I.

    2015-12-01

    The region known as Central Valleys is located in the state of Oaxaca, southern, Mexico (16.3o- 17.7 o N Lat. and 96 o - 97 o W Long.) In its central portion is settled the capital of the state. There are very few published detailed geological studies.. Geomorphological and geological features, indicates that Central Valleys and surrounding mountains conform a graben structure. Its shape is an inverted Y, centred on Oaxaca City. The study area was covered by a detailed gravity survey with a homogenous distribution of stations. The Bouguer gravity map is dominated by a large gravity low, oriented NW-SE. In order to know the characteristics of anomalies observed gravity, data transformations were used. The use of spectral methods has increased in recent years, especially for the estimation of the depth of the source. Analysis of the gravity data sheds light on the regional depth of the Graben basement and the spatial distribution of the volcanic rocks

  17. Analysis of the quality of image data acquired by the LANDSAT-4 thematic mapper and multispectral scanners. [Central Valley, California

    NASA Technical Reports Server (NTRS)

    Colwell, R. N. (Principal Investigator)

    1983-01-01

    Image products and numeric data were extracted from both TM and MSS data in an effort to evaluate the quality of these data for interpreting major agricultural resources and conditions in California's Central Valley. The utility of TM data appears excellent for meeting most of the inventory objectives of the agricultural resource specialist. These data should be extremely valuable for crop type and area proportion estimation, for updating agricultural land use survey maps at 1:24,000-scale and smaller, for field boundary definition, and for determining the size and location of individual farmsteads.

  18. Comparison of basal Silurian quartzarenites in Great Valley and Valley and Ridge provinces of central Appalachians

    SciTech Connect

    Suter, T.D.

    1987-05-01

    Throughout the Valley and Ridge province of the central Appalachians, the basal Silurian units are the Tuscarora Sandstone (quartzarenite), Rose Hill (Clinton) Formation (shale), and Keefer Sandstone (quartz subgraywacke). In the Great Valley province to the east, the basal Silurian is represented by a single quartzarenite unit, the Massanutten Sandstone. Based on similar thicknesses and stratigraphic positions, it has been assumed that the Massanutten section is equivalent to the Lower Silurian section in the Valley and ridge. Very little work has been done on the petrography of these two sections to see if there are similarities in terms of depositional environment and provenance to support this correlation. The purpose of this study is to compare the quartzarenite portions of the two sections by means of cathodoluminescence. Cathodoluminescence allows characterization of the source terrane (high versus low-temperature quartz) for a sandstone based on the luminescent colors of the quartz grains. Overall, the ratio of brown to blue luminescing quartz in the Tuscarora differs from that of the Massanutten, suggesting a different source area with more low-temperature quartz supplied to the Tuscarora. Furthermore, within the Massanutten, the ratio of brown to blue quartz decreases from the bottom to the top of the section, consistent with an increased input of high-grade metamorphic or igneous quartz through time. The possible differences in source terranes for the Tuscarora and Massanutten Sandstones are in general agreement with paleogeographic models that have been proposed for the area.

  19. Recent land-use/land-cover change in the Central California Valley

    USGS Publications Warehouse

    Soulard, Christopher E.; Wilson, Tamara S.

    2013-01-01

    Open access to Landsat satellite data has enabled annual analyses of modern land-use and land-cover change (LULCC) for the Central California Valley ecoregion between 2005 and 2010. Our annual LULCC estimates capture landscape-level responses to water policy changes, climate, and economic instability. From 2005 to 2010, agriculture in the region fluctuated along with regulatory-driven changes in water allocation as well as persistent drought conditions. Grasslands and shrublands declined, while developed lands increased in former agricultural and grassland/shrublands. Development rates stagnated in 2007, coinciding with the onset of the historic foreclosure crisis in California and the global economic downturn. We utilized annual LULCC estimates to generate interval-based LULCC estimates (2000–2005 and 2005–2010) and extend existing 27 year interval-based land change monitoring through 2010. Resulting change data provides insights into the drivers of landscape change in the Central California Valley ecoregion and represents the first, continuous, 37 year mapping effort of its kind.

  20. Packaging policies to reform the water sector: The case of the Central Valley Project Improvement Act

    NASA Astrophysics Data System (ADS)

    Fischhendler, Itay; Zilberman, David

    2005-07-01

    Existing water policies often deviate from measures suggested by economic and environmental analysis. This is particularly true in the case of drought response policies, where effective policies are rarely adopted. This study focuses on how to enhance the political feasibility of options rather than identifying the optimal water policies. It argues that a legislative policy package may be a mechanism both to unite divergent interest groups into a coalition with common policy agendas and also to fragment or realign existing and traditional alliances. This majority building approach may have a greater chance of obtaining the required political support to advance water reforms. The negotiation over the Central Valley Project Improvement Act in California is used as an example. The case study illustrates how the policy packaging strategy split the traditional power alliance between the agricultural sector and the urban sector in California and between the agricultural sector in California and their allies in other U.S. western states. At the same time, policy packaging has created new regional and sectoral advocacy coalitions in support of water reform. As a result, the Bureau of Reclamation changed its policies in the Central Valley in California relating to the establishment of water markets, water pricing, and wildlife restoration fund and allocating water for the environment.

  1. Chemical quality of ground water in the central Sacramento Valley, California

    USGS Publications Warehouse

    Fogelman, Ronald P.

    1978-01-01

    The study area includes about 1,200 square miles in the central Sacramento Valley adjacent to the Sacramento River from Knights Landing to Los Molinos, Calif. With recent agricultural development in the area, additional land has been brought under irrigation from land which had been used primarily for dry farming and grazing. This report documents the chemical character of the ground water prior to water-level declines resulting from extensive pumping for irrigation or to changes caused by extensive use of imported surface water. Chemical analyses of samples from 209 wells show that most of the area is underlain by ground water of a quality suitable for most agricultural and domestic purposes. Most of the water sampled in the area has dissolved-solids concentrations ranging from 100 to 700 milligrams per liter. The general water types for the area are a calcium magnesium bicarbonate or magnesium calcium bicarbonate and there are negligible amounts of toxic trace elements. (Woodard-USGS)

  2. Planned updates and refinements to the central valley hydrologic model, with an emphasis on improving the simulation of land subsidence in the San Joaquin Valley

    USGS Publications Warehouse

    Faunt, C.C.; Hanson, R.T.; Martin, P.; Schmid, W.

    2011-01-01

    California's Central Valley has been one of the most productive agricultural regions in the world for more than 50 years. To better understand the groundwater availability in the valley, the U.S. Geological Survey (USGS) developed the Central Valley hydrologic model (CVHM). Because of recent water-level declines and renewed subsidence, the CVHM is being updated to better simulate the geohydrologic system. The CVHM updates and refinements can be grouped into two general categories: (1) model code changes and (2) data updates. The CVHM updates and refinements will require that the model be recalibrated. The updated CVHM will provide a detailed transient analysis of changes in groundwater availability and flow paths in relation to climatic variability, urbanization, stream flow, and changes in irrigated agricultural practices and crops. The updated CVHM is particularly focused on more accurately simulating the locations and magnitudes of land subsidence. The intent of the updated CVHM is to help scientists better understand the availability and sustainability of water resources and the interaction of groundwater levels with land subsidence. ?? 2011 ASCE.

  3. Planned updates and refinements to the Central Valley hydrologic model with an emphasis on improving the simulation of land subsidence in the San Joaquin Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Hanson, Randall T.; Martin, Peter; Schmid, Wolfgang

    2011-01-01

    California's Central Valley has been one of the most productive agricultural regions in the world for more than 50 years. To better understand the groundwater availability in the valley, the U.S. Geological Survey (USGS) developed the Central Valley hydrologic model (CVHM). Because of recent water-level declines and renewed subsidence, the CVHM is being updated to better simulate the geohydrologic system. The CVHM updates and refinements can be grouped into two general categories: (1) model code changes and (2) data updates. The CVHM updates and refinements will require that the model be recalibrated. The updated CVHM will provide a detailed transient analysis of changes in groundwater availability and flow paths in relation to climatic variability, urbanization, stream flow, and changes in irrigated agricultural practices and crops. The updated CVHM is particularly focused on more accurately simulating the locations and magnitudes of land subsidence. The intent of the updated CVHM is to help scientists better understand the availability and sustainability of water resources and the interaction of groundwater levels with land subsidence.

  4. Central California Valley Ecoregion: Chapter 17 in Status and trends of land change in the Western United States--1973 to 2000

    USGS Publications Warehouse

    Sleeter, Benjamin M.

    2012-01-01

    The Central California Valley Ecoregion, which covers approximately 45,983 km2 (17,754 mi2), is an elongated basin extending approximately 650 km north to south through central California (fig. 1) (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion is surrounded entirely by the Southern and Central California Chaparral and Oak Woodlands Ecoregion, which includes parts of the Coast Ranges to the west and which is bounded by the Sierra Nevada to the east. The Central California Valley Ecoregion accounts for more than half of California’s agricultural production value and is one of the most important agricultural regions in the country, with flat terrain, fertile soils, a favorable climate, and nearly 70 percent of its land in cultivation (Kuminoff and others, 2000; Sumner and others, 2003). Commodities produced in the region include milk and dairy, cattle and calves, cotton, almonds, citrus, and grapes, among others (U.S. Department of Agriculture, 2004; Johnston and McCalla, 2004; Kuminoff and others, 2000) (figs. 2A,B,C). Six of the top eight agricultural-producing counties in California are located at least partly within the Central California Valley Ecoregion (Kuminoff and others, 2000) (table 1). The Central California Valley Ecoregion is also home to nearly 5 million people spread throughout the region, including the major cities of Sacramento (state capital), Fresno, Bakersfield, and Stockton, California (U.S. Census Bureau, 2000) (fig. 1).

  5. Reuse/disposal of agricultural drainage water with high levels of salinity and toxic trace elements in central California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural drainage waters in the western San Joaquin Valley of Central California contain high levels of salts, boron (B) and selenium (Se). Discharge of the drainage water directly into the Kesterson Reservoir in 1980's was hazardous to plants and wildlife. To investigate the plausibility of usi...

  6. Population Structure of Phytophthora infestans in the Toluca Valley Region of Central Mexico.

    PubMed

    Grünwald, N J; Flier, W G; Sturbaum, A K; Garay-Serrano, E; van den Bosch, T B; Smart, C D; Matuszak, J M; Lozoya-Saldaña, H; Turkensteen, L J; Fry, W E

    2001-09-01

    ABSTRACT We tested the hypothesis that the population of Phytophthora infestans in the Toluca valley region is genetically differentiated according to habitat. Isolates were sampled in three habitats from (i) wild Solanum spp. (WILD), (ii) land-race varieties in low-input production systems (RURAL), and (iii) modern cultivars in high-input agriculture (VALLEY). Isolates were sampled in 1988-89 (n= 179) and in 1997-98 (n= 389). In both sampling periods, the greatest genetic diversity was observed in RURAL and VALLEY habitats. Based on the Glucose-6-phosphate isomerase and Peptidase allozymes, the subpopulations from the three habitats were significantly differentiated in both sampling periods. In contrast to allozyme data for 1997-98, no differences were found among the three subpopulations for sensitivity to metalaxyl. Two groups of isolates identical for allozyme and mating type were further investigated by restriction fragment length polymorphism fingerprinting; 65% of one group and 85% of another group were demonstrated to be unique. The genetic diversity data and the chronology of disease occurrence during the season are consistent with the hypothesis that populations of P. infestans on wild Solanum populations are derived from populations on cultivated potatoes in the central highlands of Mexico near Toluca.

  7. Students, Teachers, and Schools in California's Central Valley. Research Brief. Issue #62

    ERIC Educational Resources Information Center

    Public Policy Institute of California, 2002

    2002-01-01

    This research brief provides an overview of the statistics presented in a report by Anne Danenberg, Christopher Jepsen, and Pedro Cerdan, "Student and School Indicators for Youth in California's Central Valley" (2002) [ED497305]. Twenty percent of California's public-school students attend schools in the Central Valley. Many of these…

  8. Synoptic-Dynamics of Extreme Cold Air Outbreaks Over the California Central Valley

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Grotjahn, R.

    2015-12-01

    Cold air outbreaks (CAOs) have created multi-billion dollar losses in the state of California. Especially hard hit have been agricultural operations in the California Central Valley. Criteria based on duration and extreme values of daily minimum surface temperature at 17 stations over California Central Valley and 700hPa temperature at the Oakland radiosonde station are used to identify CAOs during the period of 1950-2013. 32 strong CAO events in total are obtained with our criterion. 10 stronger CAOs are selected for detailed study. Composite analyses and bootstrap statistical tests are applied to these 10 strong CAOs and find a similar large scale meteorological pattern (LSMP) in each event. This LSMP has a ridge-trough-ridge pattern in the mass field extending from Alaska across North America to the Southeastern part of the US as the LSMP in Grotjahn & Faure (2008). A challenging problem arises in the analyses caused by the different phase speeds of waves prior to different CAO events. We use dynamical analysis methods, such as wave activity flux, three-dimensional trajectories, and temperature tendency equation terms, to reveal the synoptic-dynamical mechanisms of how the LSMP and cold air formation/migration lead to these CAOs.

  9. A summary of ground-water pumpage in the Central Valley, California, 1961-77

    USGS Publications Warehouse

    Diamond, Jonathan; Williamson, A.K.

    1983-01-01

    In the Central Valley of California, a great agricultural economy has been developed in a semiarid environment. This economy is supported by imported surface water and 9 to 15 million acre-feet per year of ground water. Estimates of ground-water pumpage computed from power consumption have been compiled and summarized. Under ideal conditions, the accuracy of the methods used is about 3 percent. This level of accuracy is not sustained over the entire study area. When pumpage for the entire area is mapped, the estimates seem to be consistent areally and through time. A multiple linear-regression model was used to synthesize data for the years 1961 through 1977, when power data were not available. The model used a relation between ground-water pumpage and climatic indexes to develop a full suite of pumpage data to be used as input to a digital ground-water model, one of the products of the Central Valley Aquifer Project. Statistical analysis of well-perforation data from drillers ' logs and water-temperature data was used to determine the percentage of pumpage that was withdrawn from each of two horizontal layers. (USGS)

  10. Searching for evidence of changes in extreme rainfall indices in the Central Rift Valley of Ethiopia

    NASA Astrophysics Data System (ADS)

    Muluneh, Alemayehu; Bewket, Woldeamlak; Keesstra, Saskia; Stroosnijder, Leo

    2016-02-01

    Extreme rainfall events have serious implications for economic sectors with a close link to climate such as agriculture and food security. This holds true in the Central Rift Valley (CRV) of Ethiopia where communities rely on highly climate-sensitive rainfed subsistence farming for livelihoods. This study investigates changes in ten extreme rainfall indices over a period of 40 years (1970-2009) using 14 meteorological stations located in the CRV. The CRV consists of three landscape units: the valley floor, the escarpments, and the highlands all of which are considered in our data analysis. The Belg (March-May) and Kiremt (June-September) seasons are also considered in the analysis. The Mann-Kendall test was used to detect trends of the rainfall indices. The results indicated that at the annual time scale, more than half (57 %) of the stations showed significant trends in total wet-day precipitation (PRCPTOT) and heavy precipitation days (R10mm). Only 7-35 % of stations showed significant trends, for the other rainfall indices. Spatially, the valley floor received increasing annual rainfall while the escarpments and the highlands received decreasing annual rainfall over the last 40 years. During Belg, 50 % of the stations showed significant increases in the maximum number of consecutive dry days (CDD) in all parts of the CRV. However, most other rainfall indices during Belg showed no significant changes. During Kiremt, considering both significant and non-significant trends, almost all rainfall indices showed an increasing trend in the valley floor and a decreasing trend in the escarpment and highlands. During Belg and Kiremt, the CDD generally showed increasing tendency in the CRV.

  11. Hydrogeology of Palm Valley, central Australia; a Pleistocene flora refuge?

    NASA Astrophysics Data System (ADS)

    Wischusen, John D. H.; Fifield, L. Keith; Cresswell, Richard G.

    2004-06-01

    The Palm Valley Oasis (Finke Gorge National Park) in arid central Australia is characterised by large stands of red cabbage palm trees ( Livistona mariae). How these unique plants, over 1000 km away from nearest relatives in the tropical parts of northern Australia persist, has long fascinated visitors. The hydrogeology of this area helps explain this phenomenon. Stable isotope (δ 2H, δ 8O) analyses shows groundwater to have a uniform composition that plots on or near a local meteoric water line. Carbon-14 results are observed to vary throughout this aquifer from effectively dead (<4%) to 87% modern carbon. Ratios of chlorine-36 to chloride range from 130 to 290×10 -1536Cl/Cl. In this region atmospheric 36Cl/Cl ratio is around 300×10 -15. Thus an age range of around 300 ka is indicated if, as is apparent radioactive decay is the only significant cause of 36Cl/Cl variation within the aquifer. The classic homogenous aquifer with varying surface topography flow model is the simplest conceptual model that need be invoked to explain these data. Complexities, associated with local topography flow cells superimposed on the regional gradient, may mean groundwater with markedly different flow path lengths has been sampled. This potential flow path complexity, which is also evidenced by slight variation in groundwater cation ratios, can account for the distribution of isotope age data throughout the aquifer. Given the likely very slow travel times indicated by this aquifer's hydraulic properties, age differences of the magnitude indicated from chlorine-36 data are feasible. The likely slow travel times (>100 ka) along some flow paths indicate groundwater discharge would endure through arid phases associated with Quaternary climate oscillations. Such a flow system can explain the persistence of this population of Palms and also highlight the possibility that Palm Valley has acted as a flora refuge since at least the mid Pleistocene.

  12. Agricultural water and energy use in the Senegal River Valley

    NASA Astrophysics Data System (ADS)

    Masiyandima, M. C.; Sow, A.

    2015-12-01

    Assessment of the productivity of irrigation water is important measuring the performance of irrigation schemes especially in water scarce areas. Equally important for performance is the energy cost of providing water for irrigation. Sahel irrigation schemes are dependent on pumping water from rivers into a network of gravity operated channels. In the Senegal River valley in Senegal the cost of pumping water and for irrigation has been estimated to be 20-25% of total rice production costs. Irrigation schemes in the valley are characterized by low water productivity. We analysed rice production, irrigation water use and energy use for supplying irrigation water at Pont Gendarme, Ndiawar and Ngallenka MCA irrigation schemes in the Senegal River valley. For the 2013 rainfall season the mean yield ranged between 6 and 8t ha-1. Dry season yield ranged between 1.7 and 6.8t ha-1. Energy use for irrigation in the Ndiawar irrigation scheme was 8kg MJ-1 and 6.4kg MJ-1 in the 2013 and 2014 rainfall seasons respectively. In 2014 (rainfall season) energy productivity of irrigation water was 8.5, 8.0 and 16.4 kg MJ-1 at Ngallenka MCA, Ndiawar and Pont Gendarme respectively. Dry season (2014) energy productivity at Ndiawar and Pont Gendarme was 3.4 and 11.2kg MJ-1 respectively. Productivity of irrigation water was similar for all schemes (0.37kg m-3 at Pont Gendarme, 0.42kg m-3 at Ngallenka MCA, and 0.41kg m-3 Ndiawar). Energy use for the supply of irrigation water in the rainfall season ranged from 403 to 1,002MJ ha-1. Dry season irrigation energy use was 589MJ ha-1 Pont Gendarme and 331MJ ha-1 at Ndiawar. Reducing water use in these schemes through better water management will result in lower production costs and increased margins for the farmers. The observations from 2013 - 2014 highlight the importance of using both water and energy productivity to assess performance of irrigation schemes.

  13. Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California’s Central Valley

    PubMed Central

    Fleskes, Joseph P.

    2017-01-01

    The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

  14. Projected impacts of climate, urbanization, water management, and wetland restoration on waterbird habitat in California’s Central Valley

    USGS Publications Warehouse

    Matchett, Elliott L.; Fleskes, Joseph

    2017-01-01

    The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

  15. Utilizing Remote Sensing Landsat 7 Data to Measure Changes in Soil Salinity in Central Valley, CA

    NASA Astrophysics Data System (ADS)

    Whitney, K. L.; El-Askary, H. M.

    2015-12-01

    Drought in California has had a major impact on agriculture in the Central Valley. A decrease in irrigation and soil moisture creates an increase in soil salinity. The are focused on south of Fresno and north of Bakersfield which is path 42 and row 35. Remote sensing data provided by Landsat 7 ETM+ remote sensing data provides 7 bands of reflection in a 30 meter by 30 meter resolution. Bands reflecting red, near infrared and short-wave infrared are used to produce indices concerning vegetation and soil salinity over 12 years. The normalized difference vegetation index (NDVI) require the red and near infrared. Two soil salinity indices (SI) are calculate one requires red, infrared and short-wave infrared bands, and the other requires green, violet and red bands. Three dates within the 12 years are studied to show changes in the NDVI and SI.

  16. Efficacy of constructed wetlands in pesticide removal from tailwaters in the Central Valley, California.

    PubMed

    Budd, Robert; O'Geen, Anthony; Goh, Kean S; Bondarenko, Svetlana; Gan, Jay

    2009-04-15

    Pollutants in agricultural irrigation return flow (tailwater) constitute a significant nonpoint source of pollution in intensive agricultural regions such as the Central Valley of California. Constructed wetlands (CWs) represent a feasible mitigation option to remove pollutants including pesticides in the tailwater. In this study, we evaluated two CWs in the Central Valley for their performance in removing pyrethroid and organophosphate insecticides under field-scale production conditions. Both CWs were found to be highly effective in reducing pyrethroid concentrations in the tailwater, with season-average concentration reductions ranging from 52 to 94%. The wetlands also reduced the flow volume by 68-87%, through percolation and evapotranspiration. When both concentration and volume reductions were considered, the season-average removal of pyrethroids ranged from 95 to 100%. The primary mechanism for pyrethroid removal was through sedimentation of pesticide-laden particles, which was influenced by hydraulic residence time and vegetation density. Temporal analysis indicates a potential efficiency threshold during high flow periods. The season-average removal of chlorpyrifos ranged 52-61%. The wetlands, however, were less effective at removing diazinon, likely due to its limited sorption to sediment particles. Analysis of pesticide partitioning showed that pyrethroids were enriched on suspended particles in the tailwater. Monitoring of pesticide association with suspended solids and bed sediments suggested an increased affinity of pyrethroids for lighter particles with the potential to move further downstream before subject to sedimentation. Results from this study show that flow-through CWs, when properly designed, are an effective practice for mitigating hydrophobic pesticides in the irrigation tailwater.

  17. New observations of VOC emissions and concentrations in, above, and around the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Goldstein, A. H.; Fares, S.; Gentner, D. R.; Park, J.; Weber, R.; Ormeno, E.; Holzinger, R.; Misztal, P. K.; Karl, T. R.; Guenther, A. B.; Fischer, M. L.; Harley, R. A.; Karlik, J. F.

    2011-12-01

    Large portions of the Central Valley of California are out of compliance with current state and federal air quality standards for ozone and particulate matter, and the relative importance of biogenic and anthropogenic VOC emissions to their photochemical production in this region remains uncertain. In 2009-2011 multiple measurement campaigns were completed investigating the VOC emission inventory and concentration distributions. In 2009 BVOC emissions from more than 20 species of major agricultural crops in California were measured in a greenhouse using branch enclosures by both PTRMS and in-situ GC. Overall, crops were found to emit low amounts of BVOC compared to the natural forests surrounding the valley. Crops mainly emitted methanol and terpenes, with a broad array of other species emitted at lower levels, and all the measured crops showed negligible emissions of isoprene. Navel oranges were the largest crop BVOC emitters measured so a full year of flux measurements were made in an orange grove near Visalia in 2010 by eddy covariance(EC)-PTRMS with two multi-week periods of concentration measurements by hourly in-situ GC, and one month of high mass resolution flux measurements by EC-PTR-TOF-MS. The dominant BVOC emissions from the orange grove were methanol and terpenes, followed by acetone, acetaldehyde, and a low level of emissions for many other species. In 2011 aircraft eddy covariance measurements of BVOC fluxes were made by EC-PTRMS covering a large area of California as part of the California Airborne Bvoc Emission Research in Natural Ecosystem Transects (CABERNET) campaign aimed at improving BVOC emission models on regional scales, mainly profiling BVOC emissions from oak woodlands surrounding the Central Valley. In 2010, hourly in-situ VOC measurements were made via in-situ GC in Bakersfield, CA as part of the CalNex experiment. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel. Measurements by

  18. Reconnaissance geology of the Central Mastuj Valley, Chitral State, Pakistan

    USGS Publications Warehouse

    Stauffer, Karl W.

    1975-01-01

    The Mastuj Valley in Chitral State is a part of the Hindu Kush Range, and is one of the structurally most complicated areas in northern Pakistan. Sedimentary rocks ranging from at least Middle Devonian to Cretaceous, and perhaps Early Tertiary age lie between ridge-forming granodiorite intrusions and are cut by thrust faults. The thrust planes dip 10? to 40? to the north- west. Movement of the upper thrust plates has been toward the southeast relative to the lower blocks. If this area is structurally typical of the Hindu-Kush and Karakoram Ranges, then these mountains are much more tectonically disturbed than previously recorded, and suggest compression on a scale compatible with the hypothesis that the Himalayan, Karakoram, and Hindu Kush Ranges form part of a continental collision zone. The thrust faults outline two plates consisting of distinctive sedimentary rocks. The lower thrust plate is about 3,000 feet thick and consists of the isoclinally folded Upper Cretaceous to perhaps lower Tertiary Reshun Formation. It has overridden the Paleozoic metasedimentary rocks of the Chitral Slate unit. This thrust plate is, in turn, overridden by an 8,000-foot thick sequence consisting largely of Devonian to Carboniferous limestones and quartzites. A key factor in the tectonic processes has been the relatively soft and plastic lithology of the siltstone layers in the Reshun Formation which have acted as lubricants along the principal thrust faults, where they are commonly found today as fault slices and smears. The stratigraphic sequence, in the central Mastuj Valley was tentatively divided into 9 mapped units. The fossiliferous shales and carbonates of the recently defined Shogram Formation and the clastlcs of the Reshun Formation have been fitted into a sequence of sedimentary rocks that has a total thick- ness of at least 13,000 feet and ranges in age from Devonian to Neogene. Minerals of potential economic significance include antimony sulfides which have been mined

  19. Hydrogeology of McMullen Valley, west-central Arizona

    USGS Publications Warehouse

    Pool, D.R.

    1987-01-01

    The geohydrology of McMullen Valley, west-central Arizona, was investigated using geologic, geophysical, and hydrologic data and a numerical model of the groundwater system. Interpretation of geologic and geophysical information indicates that the main structure of McMullen Valley is a syncline that has been normal faulted on the southeast side. Basin fill that accumulated in the structural depression during late Miocene to Pleistocene time is the main aquifer and is divided into upper and lower units on the basis of lithologic information. The upper unit is a thin layer of coarse-grained sediments and generally is not saturated. The lower unit is 3,000 to 4,000 ft thick, includes a fine-grained facies in the upper 1,000 ft, and is the main source of water. The fine-grained facies is found in the southwest half of the basin and is further divided into upper and lower parts. The lower part of the fine-grained facies has: a higher percentage of silt and clay than the upper part, contains evaporites, does not yield water to wells, and separates the aquifer into shallow and deep systems. A numerical model was used to analyze the groundwater system for both steady-state and transient conditions. The transient model was used to analyze system response to pumping stress. The transient system is one of storage depletion, and water level declines are controlled by pumping and specific yield distributions. Water level declines are also influenced by hydraulic properties and areal extent of the fine-grained facies. Significant water level declines may extend to aquifer boundaries in most of the basin; in one area, impermeable boundary greatly influences declines. The location of the nearby boundary was estimated through gravity data modeling. Several hydrologic components, including hydraulic properties and areal extent of the fine-grained facies , storage properties, and aquifer boundaries, need better definition in order to develop a more accurate model of the groundwater

  20. Commercial Agriculture and Modern Transport in Central America.

    ERIC Educational Resources Information Center

    Horst, Oscar H.

    1981-01-01

    Describes an exercise for use in college-level geography courses dealing with the tandem development of transport networks and commercial agriculture in Central America. Using six maps, the author shows the parallels between highway and railroad construction and commercial crops, (coffee, bananas, and cotton) in Central America between 1855-1975.…

  1. Effectiveness and Tradeoffs between Portfolios of Adaptation Strategies Addressing Future Climate and Socioeconomic Uncertainties in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Tansey, M. K.; Van Lienden, B.; Das, T.; Munevar, A.; Young, C. A.; Flores-Lopez, F.; Huntington, J. L.

    2013-12-01

    The Central Valley of California is one of the major agricultural areas in the United States. The Central Valley Project (CVP) is operated by the Bureau of Reclamation to serve multiple purposes including generating approximately 4.3 million gigawatt hours of hydropower and providing, on average, 5 million acre-feet of water per year to irrigate approximately 3 million acres of land in the Sacramento, San Joaquin, and Tulare Lake basins, 600,000 acre-feet per year of water for urban users, and 800,000 acre-feet of annual supplies for environmental purposes. The development of effective adaptation and mitigation strategies requires assessing multiple risks including potential climate changes as well as uncertainties in future socioeconomic conditions. In this study, a scenario-based analytical approach was employed by combining three potential 21st century socioeconomic futures with six representative climate and sea level change projections developed using a transient hybrid delta ensemble method from an archive of 112 bias corrected spatially downscaled CMIP3 global climate model simulations to form 18 future socioeconomic-climate scenarios. To better simulate the effects of climate changes on agricultural water demands, analyses of historical agricultural meteorological station records were employed to develop estimates of future changes in solar radiation and atmospheric humidity from the GCM simulated temperature and precipitation. Projected changes in atmospheric carbon dioxide were computed directly by weighting SRES emissions scenarios included in each representative climate projection. These results were used as inputs to a calibrated crop water use, growth and yield model to simulate the effects of climate changes on the evapotranspiration and yields of major crops grown in the Central Valley. Existing hydrologic, reservoir operations, water quality, hydropower, greenhouse gas (GHG) emissions and both urban and agricultural economic models were integrated

  2. 75 FR 38538 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... 1982, the Bureau of Reclamation developed and published the Criteria for Evaluating Water...

  3. 77 FR 33240 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... Bureau of Reclamation developed and published the Criteria for Evaluating Water Management...

  4. 76 FR 54251 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... Management Plans (Criteria). For the purpose of this announcement, Water Management Plans (Plans)...

  5. 76 FR 12756 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... published the Criteria for Evaluating Water Management Plans (Criteria). For the purpose of...

  6. 78 FR 21414 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... Water Management Plans (Criteria). For the purpose of this announcement, Water Management Plans...

  7. 75 FR 70020 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior ACTION: Notice of Availability. SUMMARY: The following Water Management Plans are... Bureau of Reclamation developed and published the Criteria for Evaluating Water Management...

  8. ANALYSIS OF MACROINVERTEBRATE ASSEMBLAGES IN RELATION TO ENVIRONMENTAL GRADIENTS AMONG LOTIC HABITATS OF CALIFORNIA'S CENTRAL VALLEY

    EPA Science Inventory

    We analyzed relationships between environmental characteristics and macroinvertebrate assemblages in lotic habitats of California's Central Valley with community metric and multivariate statistical approaches. Using canonical ordination analyses, we contrasted results when asse...

  9. RELATIONSHIPS BETWEEN ENVIRONMENTAL VARIABLES AND BENTHIC DIATOM ASSEMBLAGES IN CALIFORNIA CENTRAL VALLEY STREAMS (USA)

    EPA Science Inventory

    Streams and rivers in the California Central Valley Ecoregion have been substantially modified by human activities. This study examines distributional patterns of benthic diatom assemblages in relation to environmental characteristics in streams and rivers of this region. Benthic...

  10. Convergence in nitrogen deposition and cryptic isotopic variation across urban and agricultural valleys in northern Utah

    NASA Astrophysics Data System (ADS)

    Hall, S. J.; Ogata, E. M.; Weintraub, S. R.; Baker, M. A.; Ehleringer, J. R.; Czimczik, C. I.; Bowling, D. R.

    2016-09-01

    The extent to which atmospheric nitrogen (N) deposition reflects land use differences and biogenic versus fossil fuel reactive N sources remains unclear yet represents a critical uncertainty in ecosystem N budgets. We compared N concentrations and isotopes in precipitation-event bulk (wet + dry) deposition across nearby valleys in northern Utah with contrasting land use (highly urban versus intensive agriculture/low-density urban). We predicted greater nitrate (NO3-) versus ammonium (NH4+) and higher δ15N of NO3- and NH4+ in urban valley sites. Contrary to expectations, annual N deposition (3.5-5.1 kg N ha-1 yr-1) and inorganic N concentrations were similar within and between valleys. Significant summertime decreases in δ15N of NO3- possibly reflected increasing biogenic emissions in the agricultural valley. Organic N was a relatively minor component of deposition ( 13%). Nearby paired wildland sites had similar bulk deposition N concentrations as the urban and agricultural sites. Weighted bulk deposition δ15N was similar to natural ecosystems (-0.6 ± 0.7‰). Fine atmospheric particulate matter (PM2.5) had consistently high values of bulk δ15N (15.6 ± 1.4‰), δ15N in NH4+ (22.5 ± 1.6‰), and NO3- (8.8 ± 0.7‰), consistent with equilibrium fractionation with gaseous species. The δ15N in bulk deposition NH4+ varied by more than 40‰, and spatial variation in δ15N within storms exceeded 10‰. Sporadically high values of δ15N were thus consistent with increased particulate N contributions as well as potential N source variation. Despite large differences in reactive N sources, urban and agricultural landscapes are not always strongly reflected in the composition and fluxes of local N deposition—an important consideration for regional-scale ecosystem models.

  11. RELATIONSIPS BETWEEN AQUATIC INVERTEBRATE ASSEMBLAGES AND REACH AND LANDSCAPE ATTRIBUTES ON WADEABLE, WILLAMETTE VALLEY STREAMS IN AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    In summer 1997, we sampled reaches in 24 wadeable, Willamette Valley ecoregion streams draining agriculturally-infiuenced watersheds. Within these reaches, physical habitat, water chemistry, aquatic invertebrate and fish data and samples were collected. Low-level air photos were ...

  12. Subsidence in the Central Valley, California 2007 - present measured by InSAR

    NASA Astrophysics Data System (ADS)

    Farr, T. G.; Liu, Z.; Jones, C. E.

    2015-12-01

    Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with ~cm accuracy. For this study, we have obtained and analyzed Japanese PALSAR data for 2006 - 2011, Canadian Radarsat-1 data for 2011 - 2013, Radarsat-2 data for 2012 - 2015, and ESA's Sentinel-1A for 2015 and produced maps of subsidence for those periods. High resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2015. Using multiple scenes acquired by these systems, we were able to produce the time histories of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. The high resolution maps from UAVSAR were used to identify and quantify new, highly localized areas of accelerated subsidence along the California Aqueduct that occurred in 2014. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  13. Predicting the Impacts of Climate Change on Central American Agriculture

    NASA Astrophysics Data System (ADS)

    Winter, J. M.; Ruane, A. C.; Rosenzweig, C.

    2011-12-01

    Agriculture is a vital component of Central America's economy. Poor crop yields and harvest reliability can produce food insecurity, malnutrition, and conflict. Regional climate models (RCMs) and agricultural models have the potential to greatly enhance the efficiency of Central American agriculture and water resources management under both current and future climates. A series of numerical experiments was conducted using Regional Climate Model Version 3 (RegCM3) and the Weather Research and Forecasting Model (WRF) to evaluate the ability of RCMs to reproduce the current climate of Central America and assess changes in temperature and precipitation under multiple future climate scenarios. Control simulations were thoroughly compared to a variety of observational datasets, including local weather station data, gridded meteorological data, and high-resolution satellite-based precipitation products. Future climate simulations were analyzed for both mean shifts in climate and changes in climate variability, including extreme events (droughts, heat waves, floods). To explore the impacts of changing climate on maize, bean, and rice yields in Central America, RCM output was used to force the Decision Support System for Agrotechnology Transfer Model (DSSAT). These results were synthesized to create climate change impacts predictions for Central American agriculture that explicitly account for evolving distributions of precipitation and temperature extremes.

  14. Economic assessment of acid deposition and ozone damage on the San Joaquin Valley agriculture. Final report

    SciTech Connect

    Howitt, R.

    1993-02-01

    The California Agricultural Resources Model (CARM) was used to estimate the economic impact of acidic deposition and ozone on crops in the San Joaquin Valley. Data on ozone exposure-crop response and agricultural markets are used in the CARM to estimate the potential economic benefits of an improvement in air quality. The study focused on the economic impact of two ozone reduction scenarios in agricultural regions of California. The CARM projected that if growing season concentrations of ozone were reduced to 0.04 ppm, annual benefits to consumers (higher availability and lower prices) and producers (higher production and lower production costs) would be approximately $489 million. In comparison, the benefit projected if statewide levels of ozone were uniformly reduced to 0.025 ppm was approximately $1.5 billion. Although the 0.025 ppm scenario is unlikely, the economic benefits were estimated to be correspondingly large.

  15. Conservation Effects Assessment Project-Wetlands assessment in California's Central Valley and Upper Klamath River Basin

    USGS Publications Warehouse

    Duffy, Walter G.; Kahara, Sharon N.; Records, Rosemary M.

    2011-01-01

    Executive Summary-Ecosystem Services Derived from Wetlands Reserve Program Conservation Practices in California's Central Valley and Oregon's Upper Klamath River Basin. The Wetlands Reserve Program (WRP) is one of several programs implemented by the U.S. Department of Agriculture (USDA). Since the WRP's inception in 1990, it has resulted in the restoration of approximately 29,000 hectares in California's Central Valley (CCV) and roughly 12,300 hectares in Oregon's Upper Klamath River Basin (UKRB). Both the CCV and UKRB are agricultural dominated landscapes that have experienced extensive wetland losses and hydrological alteration. Restored habitats in the CCV and UKRB are thought to provide a variety of ecosystem services, but little is known about the actual benefits afforded. The U.S. Geological Survey (USGS) California Cooperative Fish and Wildlife Unit in collaboration with the USDA Natural Resources Conservation Service surveyed 70 WRP sites and 12 National Wildlife Refuge sites in the CCV, and 11 sites in the UKRB to estimate ecosystem services provided. In the CCV, sites were selected along three primary gradients; (1) restoration age, (2) management intensity, and (3) latitude (climate). Sites in the UKRB were assessed along restoration age and management intensity gradients where possible. The management intensity gradient included information about the type and frequency of conservation practices applied at each site, which was then ranked into three categories that differentiated sites primarily along a hydrological gradient. Information collected was used to estimate the following ecosystem services: Soil and vegetation nutrient content, soil loss reduction, floodwater storage as well as avian, amphibian, fish, and pollinator use and habitat availability. Prior to this study, very little was known about WRP habitat morphology in the CCV and UKRB. Therefore in this study, we described these habitats and related them to ecosystem services provided. Our

  16. The Limits of Subsistence: Agriculture and Industry in Central Appalachia.

    ERIC Educational Resources Information Center

    Pudup, Mary Beth

    Current interpretations of central Appalachia's chronic poverty focus on the region's economic dependence on the bituminous coal industry, controlled by absentee investors and serving an external market. Such theories overlook the ways in which the agricultural sector shaped subsequent industrial development. By analyzing the farm economy of 16…

  17. Paired, facing monoclines in the Sanpete-Sevier Valley area, central Utah

    USGS Publications Warehouse

    Witkind, I.J.

    1992-01-01

    Several major monoclines that trend northward through the Sanpete-Sevier Valley area of central Utah are paired and face one another. This pairing of monoclines may have occurred when near-horizontal sedimentary and volcanic strata subsided into voids created as salt was removed from a salt diapir concealed beneath valley fill. Removal was mostly by dissolution or extrusion during Neogene time. The paired monoclines, thus, are viewed as collapse features rather than as normal synclinal folds. -from Author

  18. Agricultural Business and Management Materials for Agricultural Education Programs. Core Agricultural Education Curriculum, Central Cluster.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Office of Agricultural Communications and Education.

    This curriculum guide contains 5 teaching units for 44 agricultural business and management cluster problem areas. These problem areas have been selected as suggested areas of study to be included in a core curriculum for secondary students enrolled in an agricultural education program. The five units are as follows: (1) agribusiness operation and…

  19. Agricultural Resources Materials for Agricultural Education Programs. Core Agricultural Education Curriculum, Central Cluster.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Office of Agricultural Communications and Education.

    This curriculum guide contains four units with relevant problem areas and is intended as a source unit for agricultural education. These problem areas have been selected as suggested areas of study to be included in a core curriculum for secondary students enrolled in an agricultural education program. Each problem area includes some or all of the…

  20. Evolution of the knowledge system for agricultural development in the Yaqui Valley, Sonora, Mexico

    PubMed Central

    McCullough, Ellen B.; Matson, Pamela A.

    2016-01-01

    Knowledge systems—networks of linked actors, organizations, and objects that perform a number of knowledge-related functions that link knowledge and know how with action—have played a key role in fostering agricultural development over the last 50 years. We examine the evolution of the knowledge system of the Yaqui Valley, Mexico, a region often described as the home of the green revolution for wheat, tracing changes in the functions of critical knowledge system participants, information flows, and research priorities. Most of the knowledge system's key players have been in place for many decades, although their roles have changed in response to exogenous and endogenous shocks and trends (e.g., drought, policy shifts, and price trends). The system has been agile and able to respond to challenges, in part because of the diversity of players (evolving roles of actors spanning research–decision maker boundaries) and also because of the strong and consistent role of innovative farmers. Although the agricultural research agenda in the Valley is primarily controlled from within the agricultural sector, outside voices have become an important influence in broadening development- and production-oriented perspectives to sustainability perspectives. PMID:21606365

  1. Evolution of the knowledge system for agricultural development in the Yaqui Valley, Sonora, Mexico.

    PubMed

    McCullough, Ellen B; Matson, Pamela A

    2016-04-26

    Knowledge systems-networks of linked actors, organizations, and objects that perform a number of knowledge-related functions that link knowledge and know how with action-have played a key role in fostering agricultural development over the last 50 years. We examine the evolution of the knowledge system of the Yaqui Valley, Mexico, a region often described as the home of the green revolution for wheat, tracing changes in the functions of critical knowledge system participants, information flows, and research priorities. Most of the knowledge system's key players have been in place for many decades, although their roles have changed in response to exogenous and endogenous shocks and trends (e.g., drought, policy shifts, and price trends). The system has been agile and able to respond to challenges, in part because of the diversity of players (evolving roles of actors spanning research-decision maker boundaries) and also because of the strong and consistent role of innovative farmers. Although the agricultural research agenda in the Valley is primarily controlled from within the agricultural sector, outside voices have become an important influence in broadening development- and production-oriented perspectives to sustainability perspectives.

  2. Sunflower (Helianthus annuus) pollination in California's Central Valley is limited by native bee nest site location.

    PubMed

    Sardiñas, Hillary S; Tom, Kathleen; Ponisio, Lauren Catherine; Rominger, Andrew; Kremen, Claire

    2016-03-01

    The delivery of ecosystem services by mobile organisms depends on the distribution of those organisms, which is, in turn, affected by resources at local and landscape scales. Pollinator-dependent crops rely on mobile animals like bees for crop production, and the spatial relationship between floral resources and nest location for these central-place foragers influences the delivery of pollination services. Current models that map pollination coverage in agricultural regions utilize landscape-level estimates of floral availability and nesting incidence inferred from expert opinion, rather than direct assessments. Foraging distance is often derived from proxies of bee body size, rather than direct measurements of foraging that account for behavioral responses to floral resource type and distribution. The lack of direct measurements of nesting incidence and foraging distances may lead to inaccurate mapping of pollination services. We examined the role of local-scale floral resource presence from hedgerow plantings on nest incidence of ground-nesting bees in field margins and within monoculture, conventionally managed sunflower fields in California's Central Valley. We tracked bee movement into fields using fluorescent powder. We then used these data to simulate the distribution of pollination services within a crop field. Contrary to expert opinion, we found that ground-nesting native bees nested both in fields and edges, though nesting rates declined with distance into field. Further, we detected no effect of field-margin floral enhancements on nesting. We found evidence of an exponential decay rate of bee movement into fields, indicating that foraging predominantly occurred in less than 1% of medium-sized bees' predicted typical foraging range. Although we found native bees nesting within agricultural fields, their restricted foraging movements likely centralize pollination near nest sites. Our data thus predict a heterogeneous distribution of pollination services

  3. Mapping geodiversity and cultural heritage; a case study: Aït Bou Oulli valley in central High-Atlas, Morocco.

    NASA Astrophysics Data System (ADS)

    Bouzekraoui, Hicham; Barakat, Ahmed; El Youssi, Mohammed; El Khalki, Yahia; Hafid, Abdelatif; Mouaddine, Atika

    2016-04-01

    Central High-Atlas mountain in the centre of Morocco, contains an exceptional geodiversity. Some geomorphological and geological objects of it are included and protected recently by the World Heritage list. The valley of Aït Bou Oulli is located in the heart of the Moroccan central High-Atlas, whose height is 4068 m in Ighil M'goun and 3800 m in Rat Mountain. The mountain areas are characterized by higher geodiversity in comparison with other areas. The valley possesses a geological and geomorphological heritage which is very rich, much diversified and exceptional landscapes of high mountains. It is part of geopark M'Goun; the valley attracts a number of tourists every year. However, this number remains restricted because of the lack of the tools of promotion, valuation and mediation of this geoheritage. Moreover, the touristic infrastructure is modest. Regarding this situation, the geotouristic map appears as a tool of promotion of the geotourism and diversification of the regional and national tourist product. This work aims at elaborating new maps of geomorphosites, cultural sites, and geomonuments in high Mountain landscapes of the valley, suggested in geotourism circuits. The first results reveal the low exploitation of the geodiversity of this valley-oasis: the spectacular waterfalls, water sources, canyons, glacial cirques and U-shaped valleys, superficial karstic forms (sinkholes and swallow-holes), high-Atlas peaks and cliffs, spectacular scree slopes, badlands landscapes, fairy chimneys, and the geological history dating back to the Paleozoic and angular unconformity. In addition, the valley has diverse tangible cultural heritage spanning hundreds of years such as the enigmatic rock engravings (dating from 2000 to 3000 years), troglodyte caves and terraced agriculture landscapes, geomonuments (old cooperative storage, Kasbah, traditional water mills) and the architecture of the villages. It has also an intangible cultural heritage such as folklore. This

  4. Winter fog is decreasing in the fruit growing region of the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Baldocchi, Dennis; Waller, Eric

    2014-05-01

    The Central Valley of California is home to a variety of fruit and nut trees. These trees account for 95% of the U.S. production, but they need a sufficient amount of winter chill to achieve rest and quiescence for the next season's buds and flowers. In prior work, we reported that the accumulation of winter chill is declining in the Central Valley. We hypothesize that a reduction in winter fog is cooccurring and is contributing to the reduction in winter chill. We examined a 33 year record of satellite remote sensing to develop a fog climatology for the Central Valley. We find that the number of winter fog events, integrated spatially, decreased 46%, on average, over 32 winters, with much year to year variability. Less fog means warmer air and an increase in the energy balance on buds, which amplifies their warming, reducing their chill accumulation more.

  5. Thirty Years of Cloud Cover Patterns from Satellite Data: Fog in California's Central Valley and Coast

    NASA Astrophysics Data System (ADS)

    Waller, E.; Baldocchi, D. D.

    2012-12-01

    In an effort to assess long term trends in winter fog in the Central Valley of California, custom maps of daily cloud cover from an approximately 30 year record of AVHRR (1981-1999) and MODIS (2000-2012) satellite data were generated. Spatial rules were then used to differentiate between fog and general cloud cover. Differences among the sensors (e.g., spectral content, spatial resolution, overpass time) presented problems of consistency, but concurrent climate station data were used to resolve systematic differences in products, and to confirm long term trends. The frequency and extent of Central Valley ("Tule") fog appear to have some periodic oscillation, but also appear to be on the decline, especially in the Sacramento Valley and in the "shoulder" months of November and February. These results may have strong implications for growers of fruit and nut trees in the Central Valley dependent on winter chill hours that are augmented by the foggy daytime conditions. Conclusions about long term trends in fog are limited to daytime patterns, as results are primarily derived from reflectance-based products. Similar analyses of daytime cloud cover are performed on other areas of concern, such as the coastal fog belt of California. Large area and long term patterns here appear to have periodic oscillation similar to that for the Central Valley. However, the relatively coarse spatial resolution of the AVHRR LTDR (Long Term Data Record) data (~5-km) may be limiting for fine-scale analysis of trends.

  6. Drought resilience of the California Central Valley surface-groundwater-conveyance system

    SciTech Connect

    Miller, N.L.; Dale, L.L.; Brush, C.; Vicuna, S.; Kadir, T.N.; Dogrul, E.C.; Chung, F.I.

    2009-05-15

    A series of drought simulations were performed for the California Central Valley using computer applications developed by the California Department of Water Resources and historical datasets representing a range of droughts from mild to severe for time periods lasting up to 60 years. Land use, agricultural cropping patterns, and water demand were held fixed at the 2003 level and water supply was decreased by amounts ranging between 25 and 50%, representing light to severe drought types. Impacts were examined for four hydrologic subbasins, the Sacramento Basin, the San Joaquin Basin, the Tulare Basin, and the Eastside Drainage. Results suggest the greatest impacts are in the San Joaquin and Tulare Basins, regions that are heavily irrigated and are presently overdrafted in most years. Regional surface water diversions decrease by as much as 70%. Stream-to-aquifer flows and aquifer storage declines were proportional to drought severity. Most significant was the decline in ground water head for the severe drought cases, where results suggest that under these scenarios the water table is unlikely to recover within the 30-year model-simulated future. However, the overall response to such droughts is not as severe as anticipated and the Sacramento Basin may act as ground-water insurance to sustain California during extended dry periods.

  7. Spatial use by wintering greater white-fronted geese relative to a decade of habitat change in California's Central Valley

    USGS Publications Warehouse

    Ackerman, J.T.; Takekawa, J.Y.; Orthmeyer, D.L.; Fleskes, J.P.; Yee, J.L.; Kruse, K.L.

    2006-01-01

    We investigated the effect of recent habitat changes in California's Central Valley on wintering Pacific greater white-fronted geese (Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 1987-1990 and 1998-2000. These habitat changes included wetland restoration and agricultural land enhancement due to the 1990 implementation of the Central Valley Joint Venture, increased land area used for rice (Oryza sativa) production, and the practice of flooding, rather than burning, rice straw residues for decomposition because of burning restrictions enacted in 1991. Using radiotelemetry, we tracked 192 female geese and recorded 4,516 locations. Geese traveled shorter distances between roosting and feeding sites during 1998-2000 (24.2 ?? 2.2 km) than during 1987-1990 (32.5 ?? 3.4 km); distance traveled tended to decline throughout winter during both decades and varied among watershed basins. Population range size was smaller during 1998-2000 (3,367 km2) than during 1987-1990 (5,145 km2), despite a 2.2-fold increase in the size of the Pacific Flyway population of white-fronted geese during the same time period. The population range size also tended to increase throughout winter during both decades. Feeding and roosting distributions of geese also differed between decades; geese shifted into basins that had the greatest increases in the amount of area in rice production (i.e., American Basin) and out of other basins (i.e., Delta Basin). The use of rice habitat for roosting (1987-1990: 40%, 1998-2000: 54%) and feeding (1987-1990: 57%, 1998-2000: 72%) increased between decades, whereas use of wetlands declined for roosting (1987-1990: 36%, 1998-2000: 31%) and feeding (1987-1990: 22%, 1998-2000: 12%). Within postharvested rice habitats, geese roosted and fed primarily in burned rice fields during 1987-1990 (roost: 43%, feed: 34%), whereas they used flooded rice fields during 1998-2000 (roost: 78%, feed: 64

  8. On the formation of the tunnel valleys of the Superior lobe, central Minnesota

    NASA Astrophysics Data System (ADS)

    Moores, Howard D.

    1989-07-01

    When considering the formation of tunnel valleys, most researchers have appealed to basal melting as the primary source of water. Erosion of the tunnel valleys can then be accomplished by steady-state drainage over a long period or by storage and subsequent catastrophic release. However, field relationships in a large system of tunnel valleys formed by the Superior lobe in central Minnesota indicate that another source of water must be considered. The Minnesota tunnel valleys are composed of individual segments 10-20 km long, and the segments commonly terminate in subaerial outwash fans at recessional ice margin positions. Eskers, associated with the tunnel valleys, are also composed of short segments, frequently beginning at moulin kames and terminating at the head of outwash fans. The dominant source of the water responsible for tunnel-valley formation was seasonal meltwater from the glacier surface that reached the bed through moulins and crevasses. The apparent continuity of the valleys resulted from the headward development of the englacial drainage system during ice retreat.

  9. Data network, collection, and analysis in the Diamond Valley flow system, central Nevada

    USGS Publications Warehouse

    Knochenmus, Lari A.; Berger, David L.; Moreo, Michael T.; Smith, J. LaRue

    2011-01-01

    Future groundwater development and its effect on future municipal, irrigation, and alternative energy uses in the Diamond Valley flow system are of concern for officials in Eureka County, Nevada. To provide a better understanding of the groundwater resources, the U.S. Geological Survey, in cooperation with Eureka County, commenced a multi-phase study of the Diamond Valley flow system in 2005. Groundwater development primarily in southern Diamond Valley has resulted in water-level declines since the 1960s ranging from less than 5 to 100 feet. Groundwater resources in the Diamond Valley flow system outside of southern Diamond Valley have been relatively undeveloped. Data collected during phase 2 of the study (2006-09) included micrometeorological data at 4 evapotranspiration stations, 3 located in natural vegetation and 1 located in an agricultural field; groundwater levels in 95 wells; water-quality constituents in aquifers and springs at 21 locations; lithologic information from 7 recently drilled wells; and geophysical logs from 3 well sites. This report describes what was accomplished during phase 2 of the study, provides the data collected, and presents the approaches to strengthen relations between evapotranspiration rates measured at micrometeorological stations and spatially distributed groundwater discharge. This report also presents the approach to improve delineation of areas of groundwater discharge and describes the current methodology used to improve the accuracy of spatially distributed groundwater discharge rates in the Diamond Valley flow system.

  10. Virtual water flows related to land use in an intensive agriculture in the Fergana Valley, Uzbekistan

    NASA Astrophysics Data System (ADS)

    Klipstein, A.; Schneider, K.; Breuer, L.; Frede, H. G.

    2009-04-01

    Due to low annual precipitation, agricultural production in Uzbekistan is depending on irrigation from the Syrdarya and Amudarya rivers to a great deal. One of the most important cash crops of the country is cotton. Current irrigation management leads to elevated groundwater levels, salinization of soils and to a degradation of soil and water resources. Through export of cotton and other crops, the problems related to water consumption and water management are transported beyond the producing country. The amount of water transported through production and export is referred to as virtual water. To distinguish between productive and unproductive partitioning of water flows, the terms green and blue water have been introduced. Information on virtual water flows due to crop production usually only exist on country level. To reduce uncertainties related to generalization, the effect of land management and environmental factors on the partitioning of water flows needs to be studied on smaller scales. The presented study analyzes water fluxes in an intensively used agricultural area in the Fergana Valley, Uzbekistan. The study aims to a) quantify crop specific water consumption in agricultural production under current management and b) analyze water use efficiency as subject to land use and irrigation management. Based on crop production, irrigation management and environmental conditions in the study area, virtual water flows will be calculated on the level of agricultural collectives (Water Users Associations). In a further step, the partitioning of green and blue water fluxes will be quantified. Alternative scenarios for improved water management will be analyzed in a model study.

  11. Ground-water areas and well logs, central Sevier Valley, Utah

    USGS Publications Warehouse

    Young, Richard A.

    1960-01-01

    Between September 1959 and June 1960 the United States Geological Survey and the Utah State Engineer, with financial assistance from Garfield, Millard, Piute, Sanpete, and Sevier Counties and from local water-users’ associations, cooperated in an investigation to determine the structural framework of the central Sevier Valley and to evaluate the valley’s ground-water potential. An important aspect of the study was the drilling of 22 test holes under private contract. These data and other data collected during the course of the larger ground-water investigation of which the test drilling was a part will be evaluated in a report on the geology and ground-water resources of the central Sevier Valley. The present report has been prepared to make available the logs of test holes and to describe in general terms the availability of ground water in the different areas of the valley.

  12. Patterns and controls of nitrous oxide emissions from waters draining a subtropical agricultural valley

    NASA Astrophysics Data System (ADS)

    Harrison, John; Matson, Pamela

    2003-09-01

    Although nitrous oxide (N2O) emission from agricultural runoff is thought to constitute a globally important source of this greenhouse gas, N2O flux from polluted aquatic systems is poorly understood and scarcely reported, especially in low-latitude (0°-30°) regions where rapid agricultural intensification is occurring. We measured N2O emissions, dissolved N2O concentrations, and factors likely to control rates of N2O production in drainage canals receiving agricultural and mixed agricultural/urban inputs from the intensively farmed Yaqui Valley of Sonora, Mexico. Average per-area N2O flux in both purely agricultural and mixed urban/agricultural drainage systems (16.5 ng N2O-N cm-2 hr-1) was high compared to other fresh water fluxes, and extreme values ranged up to 244.6 ng N2O-N cm-2 hr-1. These extremely high N2O fluxes occurred during green algae blooms, when organic carbon, nitrogen, and oxygen concentrations were high, and only in canals receiving pig-farm and urban inputs, suggesting an important link between land-use and N2O emissions. N2O concentrations and fluxes correlated significantly with water column concentrations of nitrate, particulate organic carbon and nitrogen, ammonium, and chlorophyll a, and a multiple linear regression model including ammonium, dissolved organic carbon, and particulate organic carbon was the best predictor of [N2O] (r2 = 52%). Despite high per-area N2O fluxes, our estimate of regional N2O emission from surface drainage (20,869 kg N2O-N yr-1; 0.046% of N-fertilizer inputs) was low compared to values predicted by algorithms used in global budgets.

  13. Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California

    USGS Publications Warehouse

    Petrie, Mark J.; Fleskes, Joseph P.; Wolder, Mike A.; Isola, Craig R.; Yarris, Gregory S.; Skalos, Daniel A.

    2016-01-01

    We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.

  14. 78 FR 63491 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... developed and published the Criteria for Evaluating Water Management Plans (Criteria). For the purpose...

  15. 77 FR 64544 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... and published the Criteria for Evaluating Water Management Plans (Criteria). For the purpose of...

  16. Evaluation of the Central Valley Partnership of the James Irvine Foundation

    ERIC Educational Resources Information Center

    Campbell, Martha S.; Patton, Michael Quinn; Patrizi, Patricia

    2005-01-01

    The Central Valley Partnership (CVP) was the centerpiece of the Civic Culture Program area of the James Irvine Foundation headquartered in San Francisco. Initiated in 1996 as a "partnership for citizenship," CVP had three objectives: (1) assisting and supporting immigrants seeking citizenship; (2) promoting active civic participation…

  17. Barriers to Coverage of Transborder Environmental Issues in the Ferghana Valley of Central Asia

    ERIC Educational Resources Information Center

    Freedman, Eric

    2014-01-01

    Three former Soviet republics occupy Central Asia's Ferghana Valley, a region of serious transborder environmental problems, especially ones that involve water and energy. Most news organizations in Kyrgyzstan, Tajikistan, and Uzbekistan provide little in-depth coverage of these issues. Journalists in one country usually do not seek news sources…

  18. Glyphosate-resistant hairy fleabane (Conyza bonariensis) Documented in the Central Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years poor control of hairy fleabane (Conyza bonariensis) with glyphosate has been reported by growers and pest consultants in some areas of the Central Valley. Since glyphosate-resistance in a related species horseweed (Conyza canadensis) was recently documented in similar locations, we ...

  19. 76 FR 58840 - Central Valley Project Improvement Act; Refuge Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-22

    ... Bureau of Reclamation Central Valley Project Improvement Act; Refuge Water Management Plans AGENCY... Refuge Water Management Plans (Refuge Criteria). Several entities have each developed a Refuge Water... requirements of these Refuge Criteria (see list in Supplementary Information below). Willow Creek Mutual...

  20. Character and evolution of the ground-water flow system in the central part of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, K.R.

    1988-01-01

    The occurrence of selenium in agricultural drain water derived from the western San Joaquin Valley, California, has focused concern on the groundwater flow system of the western valley. Previous work and recently collected texture and water level data were used to evaluate the character and evolution of the regional groundwater flow system in the central part of the western valley, with particular emphasis on the deposits overlying the Corcoran Clay Member of the Tulane Formation. The Corcoran Clay Member, where present, divides the flow system into an upper semiconfined zone and a lower confined zone. Above the Corcoran, three geohydrologic units can be recognized: Coast Range alluvium, Sierran sand, and flood-basin deposits. These units differ in texture, hydrologic properties, and oxidation state. The development of irrigated agriculture in the central part of the western valley has significantly altered the flow system. Percolation of irrigation water past crop roots has caused a rise in the altitude of the water table in mid-fan and distal-fan areas. Pumpage of groundwater from wells has caused a lowering of the water table beneath parts of the fanheads and a lowering of the potentiometric surface of the confined zone over much of the western valley. The combination of percolation and pumpage has resulted in development of a large downward hydraulic head gradient in the semi-confined zone and has created a groundwater divide along the western margin of the valley. Surface water deliveries from the California Aqueduct have allowed a decrease in pumpage and a consequent recovery in hydraulic head throughout the system. (Author 's abstract)

  1. Can We Mitigate Climate Extremes using Managed Aquifer Recharge: Case Studies California Central Valley and South-Central Arizona, USA

    NASA Astrophysics Data System (ADS)

    Scanlon, B. R.; Reedy, R. C.; Faunt, C. C.; Pool, D. R.; Uhlman, K.

    2015-12-01

    Frequent long-term droughts interspersed with intense floods in the southwestern U.S. underscore the need to store more water to manage these climate extremes. Here we show how managed aquifer recharge can enhance drought resilience in the southwestern U.S. with ~ 70% of California under extreme drought and 75% of Arizona under moderate drought. Data on water sources, transportation, and users were compiled for managed aquifer recharge systems in the Central Valley and south-central Arizona. Groundwater depletion of 115 to 145 km3 in the 1900s created large subsurface reservoirs in thick alluvial basins in these regions. Large canals and aqueducts up to several 100 km long allow water to be imported from reservoirs, mostly in more humid regions. Imported water is either used instead of groundwater or is applied in surface spreading basins primarily during wet periods (≤1.3 km3/yr Central Valley, ≤0.7 km3/yr Arizona) and is extracted during droughts. The dominant water users include irrigators and municipalities both within and outside the managed aquifer recharge systems. Groundwater modeling indicates that recharge basins significantly increase groundwater storage in the Central Valley. Managed aquifer recharge systems significantly enhance drought resilience and increase sustainability of water resources in semiarid regions, complementing surface water reservoirs and conjunctive surface water/groundwater use by providing longer term storage.

  2. Genetics of Central Valley O. mykiss populations: drainage and watershed scale analyses

    USGS Publications Warehouse

    Nielsen, Jennifer L.; Pavey, Scott A.; Wiacek, Talia; Williams, Ian S.

    2005-01-01

    Genetic variation at 11 microsatellite loci described population genetic structure for Oncorhynchus mykiss in the Central Valley, California. Spatial and temporal variation was examined as well as relationships between hatchery and putative natural spawning anadromous stocks. Genetic diversity was analyzed at two distinct spatial scales: fine-scale within drainage for five populations on Clear Creek; between and among drainage diversity for 23 populations. Significant regional spatial structure was apparent, both within Clear Creek and among rainbow trout populations throughout the Central Valley. Significant differences in allelic frequencies were found among most river or drainage systems. Less than 1% of the molecular variance could be attributed to differences found between drainages. Hatchery populations were shown to carry similar genetic diversity to geographically proximate wild populations. Central Valley M = 0.626 (below the M < 0.68 threshold) supported recent population reductions within the Central Valley. However, average estimated effective population size was relatively high (Ne = 5066). Significant allelic differences were found in rainbow trout collected above and below impassable dams on the American, Yuba, Stanislaus and Tuolumne rivers. Rainbow trout sampled in Spring Creek were extremely bottlenecked with allelic variation at only two loci and an estimated effective population size of 62, suggesting some local freshwater O. mykiss stocks may be declining rapidly. These data support significant genetic population structure for steelhead and rainbow trout populations within the Central Valley across multiple scales. Careful consideration of this genetic diversity and its distribution across the landscape should be part of future conservation and restoration efforts. 

  3. Sustainable conjunctive water management in irrigated agriculture: Model formulation and application to the Yaqui Valley, Mexico

    NASA Astrophysics Data System (ADS)

    Schoups, Gerrit; Addams, C. Lee; Minjares, José Luis; Gorelick, Steven M.

    2006-10-01

    This paper investigates strategies to alleviate the effects of droughts on the profitability and sustainability of irrigated agriculture. These strategies include conjunctive management of surface water and groundwater resources, and engineered improvements such as lining of irrigation canals and addition of regional pumping well capacity. A spatially distributed simulation-optimization model was developed for an irrigated system consisting of multiple surface water reservoirs and an alluvial aquifer. The simulation model consists of an agronomic component and simulators describing the hydrologic system. The physical models account for storage and flow through the reservoirs, routing through the irrigation canals, and regional groundwater flow. The agronomic model describes crop productivity as a function of irrigation quantity and salinity, and determines agricultural profit. A profit maximization problem was formulated and solved using large-scale constrained gradient-based optimization. The model was applied to a real-world conjunctive surface water/groundwater management problem in the Yaqui Valley, an irrigated agricultural region in Sonora, Mexico. The model reproduces recorded reductions in agricultural production during a historical drought. These reductions were caused by a decline in surface water availability and limited installed pumping capacity. Results indicate that the impact of the historical 8-year drought could have been significantly reduced without affecting profit in wet years by better managing surface water and groundwater resources. Namely, groundwater could have been more heavily relied upon and surface water allocation capped at a sustainable level as an operating rule. Lining the irrigation canals would have resulted in water savings of 30% of historical reservoir releases during wet years, which could have been used in subsequent drier years to increase agricultural production. The benefits of a greater reliance on groundwater pumping

  4. Denitrification potential of different land-use types in an agricultural watershed, lower Mississippi valley

    USGS Publications Warehouse

    Ullah, S.; Faulkner, S.P.

    2006-01-01

    Expansion of agricultural land and excessive nitrogen (N) fertilizer use in the Mississippi River watershed has resulted in a three-fold increase in the nitrate load of the river since the early 1950s. One way to reduce this nitrate load is to restore wetlands at suitable locations between croplands and receiving waters to remove run-off nitrate through denitrification. This research investigated denitrification potential (DP) of different land uses and its controlling factors in an agricultural watershed in the lower Mississippi valley (LMV) to help identify sites with high DP for reducing run-off nitrate. Soil samples collected from seven land-use types of an agricultural watershed during spring, summer, fall and winter were incubated in the laboratory for DP determination. Low-elevation clay soils in wetlands exhibited 6.3 and 2.5 times greater DP compared to high-elevation silt loam and low-elevation clay soils in croplands, respectively. DP of vegetated-ditches was 1.3 and 4.2 times that of un-vegetated ditches and cultivated soils, respectively. Soil carbon and nitrogen availability, bulk density, and soil moisture significantly affected DP. These factors were significantly influenced in turn by landscape position and land-use type of the watershed. It is evident from these results that low-elevation, fine-textured soils under natural wetlands are the best locations for mediating nitrate loss from agricultural watersheds in the LMV. Landscape position and land-use types can be used as indices for the assessment/modeling of denitrification potential and identification of sites for restoration for nitrate removal in agricultural watersheds. ?? 2006 Elsevier B.V. All rights reserved.

  5. Seroprevalence survey of American trypanosomiasis in Central Valley of Toluca.

    PubMed

    Quijano-Hernández, Israel A; Castro-Barcena, Alejandro; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Del Ángel-Caraza, Javier; Vázquez-Chagoyán, Juan C

    2012-01-01

    American trypanosomiasis is a growing health issue in the Americas. México is an endemic country, where some locations such as in the State of México are considered highly prevalent. In the valley of Toluca city, the capital of the State of Mexico, there exists an apparent high prevalence in dogs. The absence of triatomine vectors suggests that dogs may not be infected. Therefore, we conducted a directed survey to domiciliated and nondomiciliated dogs to reassess dogs' T. cruzi seroprevalence status. HAI and ELISA serologic tests were applied to 124 and 167 serums of domiciliated and nondomiciliated dogs in the target city. Risk factors were estimated, but the results did not show any evidence to assess them. No domiciliated dogs tested positive to both tests, whereas only one non-domiciliated dog resulted positive. This animal may have acquired the infection in an endemic area and then migrated to Toluca. Research results indicate that T. cruzi infection is not actively transmitted among dogs, and it is pointed out that dogs are the main sentinel animal population to evaluate a possible expansion of the territory affected by Chagas' disease.

  6. Groundwater Age in Multi-Level Water Quality Monitor Wells on California Central Valley Dairies

    NASA Astrophysics Data System (ADS)

    Esser, B. K.; Visser, A.; Hillegonds, D. J.; Singleton, M. J.; Moran, J. E.; Harter, T.

    2011-12-01

    Dairy farming in California's Central Valley is a significant source of nitrate to underlying aquifers. One approach to mitigation is to implement farm-scale management plans that reduce nutrient loading to groundwater while sustaining crop yield. While the effect of different management practices on crop yield is easily measured, their effect on groundwater quality has only infrequently been evaluated. Documenting and predicting the impact of management on water quality requires a quantitative assessment of transport (including timescale and mixing) through the vadose and saturated zones. In this study, we measured tritium, helium isotopic composition, and noble gas concentrations in groundwater drawn from monitor wells on several dairies in the Lower San Joaquin Valley and Tulare Lake Basin of California's Central Valley in order to predict the timescales on which changes in management may produce observable changes in groundwater quality. These dairies differ in age (from <10 to >100 years old), thickness of the vadose zone (from <10 to 60 m), hydrogeologic setting, and primary source of irrigation water (surface or groundwater). All of the dairies use manure wastewater for irrigation and fertilization. Three of the dairies have implemented management changes designed to reduce nutrient loading and/or water usage. Monitor wells in the southern Tulare Lake Basin dairies were installed by UC-Davis as multi-level nested wells allowing depth profiling of tritium and noble gases at these sites. Tritium/helium-3 groundwater ages, calculated using a simple piston-flow model, range from <2 to >50 years. Initial tritium (the sum of measured tritium and tritiogenic helium-3) is close to or slightly above precipitation in the calculated recharge year for young samples; and significantly above the precipitation curve for older samples. This pattern is consistent with the use of 20-30 year old groundwater recharged before 1980 for irrigation, and illustrates how irrigation

  7. Estimation of Evapotranspiration of Almond orchards using Remote Sensing based SEBAL model in Central Valley, California

    NASA Astrophysics Data System (ADS)

    Roy, S.; Ustin, S.; Kefauver, S. C.

    2009-12-01

    Evapotranspiration is one of the main components of the hydrologic cycle and its impact to hydrology, agriculture,forestry and environmental studies is very crucial. SEBAL (Surface Energy Balance Algorithm for Land) is an image-processing model comprised of twenty-five computational sub-models that computes actual evapotranspiration (ETa) and other energy exchanges as a component of energy balance which is used to derive the surface radiation balance equation for the net surface radiation flux (Rn) on a pixel-by-pixel basis. For this study, SEBAL method is applied to Level 1B dataset of visible, near-infrared and thermal infrared radiation channels of MASTER instrument on-board NASA-DC 8 flight. This paper uses the SEBAL method to (1) investigate the spatial distribution property of land surface temperature (Ls), NDVI, and ETa over the San Joaquin valley. (2) Estimate actual evapotranspiration of almond class on pixel-by-pixel basis in the Central valley, California. (3) Comparison of actual Evapotranspiration obtained from SEBAL model with reference evapotranspiration (Eto) using Penman Monteiths method based on the procedures and available data from California Irrigation Management Information System (CIMIS) stations. The results of the regression between extracted land surface temperature, NDVI and, evapotranspiration show negative (-) correlation. On the other hand Ls possessed a slightly stronger negative correlation with the ETa than with NDVI for Almond class. The correlation coefficient of actual ETa estimates from remote sensing with Reference ETo from Penmann Monteith are 0.8571. ETa estimated for almond crop from SEBAL were found to be almost same with the CIMIS_Penman Monteith method with bias of 0.77 mm and mean percentage difference is 0.10%. These results indicate that combination of MASTER data with surface meteorological data could provide an efficient tool for the estimation of regional actual ET used for water resources and irrigation scheduling

  8. Geophysical Data from Spring Valley to Delamar Valley, East-Central Nevada

    USGS Publications Warehouse

    Mankinen, Edward A.; Roberts, Carter W.; McKee, Edwin H.; Chuchel, Bruce A.; Morin, Robert L.

    2007-01-01

    Cenozoic basins in eastern Nevada and western Utah constitute major ground-water recharge areas in the eastern part of the Great Basin and these were investigated to characterize the geologic framework of the region. Prior to these investigations, regional gravity coverage was variable over the region, adequate in some areas and very sparse in others. Cooperative studies described herein have established 1,447 new gravity stations in the region, providing a detailed description of density variations in the middle to upper crust. All previously available gravity data for the study area were evaluated to determine their reliability, prior to combining with our recent results and calculating an up-to-date isostatic residual gravity map of the area. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill in the major valleys of the study area. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a much improved view of subsurface shapes of these basins and provides insights useful for the development of hydrogeologic models for the region.

  9. Assessment of regional change in nitrate concentrations in groundwater in the Central Valley, California, USA, 1950s-2000s

    USGS Publications Warehouse

    Burow, Karen R.; Jurgens, Bryant C.; Belitz, Kenneth; Dubrovsky, Neil M.

    2013-01-01

    A regional assessment of multi-decadal changes in nitrate concentrations was done using historical data and a spatially stratified non-biased approach. Data were stratified into physiographic subregions on the basis of geomorphology and soils data to represent zones of historical recharge and discharge patterns in the basin. Data were also stratified by depth to represent a shallow zone generally representing domestic drinking-water supplies and a deep zone generally representing public drinking-water supplies. These stratifications were designed to characterize the regional extent of groundwater with common redox and age characteristics, two factors expected to influence changes in nitrate concentrations over time. Overall, increasing trends in nitrate concentrations and the proportion of nitrate concentrations above 5 mg/L were observed in the east fans subregion of the Central Valley. Whereas the west fans subregion has elevated nitrate concentrations, temporal trends were not detected, likely due to the heterogeneous nature of the water quality in this area and geologic sources of nitrate, combined with sparse and uneven data coverage. Generally low nitrate concentrations in the basin subregion are consistent with reduced geochemical conditions resulting from low permeability soils and higher organic content, reflecting the distal portions of alluvial fans and historical groundwater discharge areas. Very small increases in the shallow aquifer in the basin subregion may reflect downgradient movement of high nitrate groundwater from adjacent areas or overlying intensive agricultural inputs. Because of the general lack of regionally extensive long-term monitoring networks, the results from this study highlight the importance of placing studies of trends in water quality into regional context. Earlier work concluded that nitrate concentrations were steadily increasing over time in the eastern San Joaquin Valley, but clearly those trends do not apply to other

  10. Ethiopian Central Rift Valley basin hydrologic modelling using HEC-HMS and ArcSWAT

    NASA Astrophysics Data System (ADS)

    Pascual-Ferrer, Jordi; Candela, Lucila; Pérez-Foguet, Agustí

    2013-04-01

    An Integrated Water Resources Management (IWRM) shall be applied to achieve a sustainable development, to increase population incomes without affecting lives of those who are highly dependent on the environment. First step should be to understand water dynamics at basin level, starting by modeling the basin water resources. For model implementation, a large number of data and parameters are required, but those are not always available, especially in some developing countries where different sources may have different data, there is lack of information on data collection, etc. The Ethiopian Central Rift Valley (CRV) is an endorheic basin covering an area of approximately 10,000 km2. For the period 1996-2005, the average annual volume of rainfall accounted for 9.1 Mm3, and evapotranspiration for 8 Mm3 (Jansen et al., 2007). From the environmental point of view, basin ecosystems are endangered due to human activities. Also, poverty is widespread all over the basin, with population mainly living from agriculture on a subsistence economy. Hence, there is an urgent need to set an IWRM, but datasets required for water dynamics simulation are not too reliable. In order to reduce uncertainty of numerical simulation, two semi-distributed open software hydrologic models were implemented: HEC-HMS and ArcSWAT. HEC-HMS was developed by the United States Army Corps of Engineers (USACoE) Hydrologic Engineering Center (HEC) to run precipitation-runoff simulations for a variety of applications in dendritic watershed systems. ArcSWAT includes the SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) model developed for the USDA Agricultural Research Service into ArcGIS (ESRI®). SWAT was developed to assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time (Neitsch et al., 2005). According to this, ArcSWAT would be the best option for IWRM implementation in the basin. However

  11. Modeling Land Application of Food-Processing Wastewater in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Rubin, Y.; Benito, P.; Miller, G.; McLaughlin, J.; Hou, Z.; Hermanowicz, S.; Mayer, U.

    2007-12-01

    California's Central Valley contains over 640 food-processing plants, serving a multi-billion dollar agricultural industry. These processors consume approximately 7.9 x 107 m3 of water per year. Approximately 80% of these processors discharge the resulting wastewater, which is typically high in organic matter, nitrogen, and salts, to land, and many of these use land application as a treatment method. Initial investigations revealed elevated salinity levels to be the most common form of groundwater degradation near land application sites, followed by concentrations of nitrogen compounds, namely ammonia and nitrate. Enforcement actions have been taken against multiple food processors, and the regulatory boards have begun to re-examine the land disposal permitting process. This paper summarizes a study that was commissioned in support of these actions. The study has multiple components which will be reviewed briefly, including: (1) characterization of the food-processing related waste stream; (2) fate and transport of the effluent waste stream in the unsaturated zone at the land application sites; (3) fate and transport of the effluent waste stream at the regional scale; (4) predictive uncertainty due to spatial variability and data scarcity at the land application sites and at the regional scale; (5) problem mitigation through off-site and in-situ actions; (6) long-term solutions. The emphasis of the talk will be placed on presenting and demonstrating a stochastic framework for modeling the transport and attenuation of these wastes in the vadose zone and in the saturated zone, and the related site characterization needs, as affected by site conditions, water table depth, waste water application rate, and waste constituent concentrations.

  12. Tracing groundwater recharge in the San Luis Valley, Colorado: Groundwater contamination susceptibility in an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Patel, Tanya; Hindshaw, Ruth; Singer, Michael

    2015-04-01

    Water is a vital resource in any agricultural watershed, yet in the arid western United States farming practices threaten the quality and availability of groundwater. This is a pressing concern in the San Luis Valley, southern Colorado, where agriculture comprises 30% of the local economy, and employs over half the valley population. Although 54 % of the water used for irrigation is surface water, farmers do not usually apply this water directly to their fields. Instead, the water is often diverted into pits which recharge the aquifer, and the water is subsequently pumped during the following irrigation season. The Rio Grande Water Conservation District recognises that recharge to the unconfined aquifer has been outpaced by commercial irrigation for at least four decades, resulting in a decline in groundwater levels. Recycled irrigation water, and leakage from unlined canals now represent the greatest recharge contribution to the unconfined aquifer in this region. This makes the shallow groundwater particularly susceptible to agricultural contamination. The purpose of this study is to assess groundwater contamination in the unconfined and upper confined aquifers of the San Luis Valley, which are the most susceptible to contamination due to their close proximity to the surface. Although concentrations of potentially harmful contaminants from agricultural runoff are regularly monitored, the large spatial and temporal fluctuations in values make it difficult to determine long-term trends. We have analysed δ18O, δ2H and major-ion chemistry of 57 groundwater, stream and precipitation samples, collected in June 2014, and interpreted them alongside regional stream flow data and groundwater levels. This will allow us to study the seasonality and locality of groundwater recharge to provide greater insight into the watershed's potential for pollution. A groundwater vulnerability assessment was performed using the model DRASTIC (Depth to water, Recharge, Aquifer media, Soil

  13. Geophysical Investigation of Avon Valley, West-Central Montana, using Gravity and Seismic Reflection Profiling

    NASA Astrophysics Data System (ADS)

    Knatterud, L.; Mosolf, J.; Speece, M. A.; Zhou, X.

    2014-12-01

    The Avon Valley and adjacent mountains in west-central Montana lie within the Lewis and Clark Line, a major system of WNW-striking faults and folds that transect the more northerly structural grain of the northern Rockies and represent alternating episodes of transtensional and transpressional deformation. The northwest-trending valley has been previously interpreted as an extensional half graben filled with Tertiary sedimentary and volcanic deposits; however, little-to-no geophysical constraints on basin architecture or the thickness of Tertiary fill have been reported. A major northwest-striking fault with significant normal displacement clearly bounds the valley to the northeast, juxtaposing Tertiary sedimentary deposits against Proterozoic-Mesozoic units deformed by shortening structures and crosscut by Cretaceous granitic intrusions. Tertiary volcanic deposits unconformably overlying faulted and folded Phanerozoic-Proterozoic sequences in the eastern Garnet Range bound the valley to the southwest, but in the past no faults had been mapped along this margin. New mapping by the Montana Bureau of Mines and Geology (MBMG) has identified a system of high-angle, northwest- and northeast-striking, oblique-slip faults along the southwest border of the Avon calling into question if the valley is a half, full, or asymmetrical graben. Geophysical data has recently been acquired by Montana Tech to help define the structural architecture of the Avon Valley and the thickness of its Tertiary fill. Gravity data and a short seismic reflection profile have been collected and a preliminary interpretation of these data indicates a half graben with a series of normal faults bounding the western side of the valley. Ongoing gravity data collection throughout 2014 should refine this interpretation by better defining the bedrock-Tertiary interface at depth.

  14. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    PubMed Central

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley. PMID:22645352

  15. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley.

    PubMed

    Scanlon, Bridget R; Faunt, Claudia C; Longuevergne, Laurent; Reedy, Robert C; Alley, William M; McGuire, Virginia L; McMahon, Peter B

    2012-06-12

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km(3) of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km(3), occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km(3) shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  16. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  17. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  18. Using Imaging Spectrometry to Identify Crops in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Shivers, S.; Roberts, D. A.

    2015-12-01

    With a growing global population, limited resources and a changing climate, understanding and monitoring the distribution of our food and water resources is essential to their sustainability. Regional food yield estimates and water resource accounting are dependent upon accurate agricultural records. Crop mapping provides farmers, managers, and policymakers the information necessary to anticipate annual food supplies and water demands by better understanding the distribution of species. While on the ground crop accounting usually happens yearly at the county level and requires significant time and labor inputs, remote sensing has the potential to map crops and monitor their health over a greater spatial area with more frequent time intervals. Specifically, imaging spectrometers have the capability to produce imagery at high spectral and spatial resolutions, which may allow for differentiation of crops at the field-level scale. In this research 14 crop species and soil were classified in Kern County, California using canonical discriminant analysis (CDA) and Multiple Endmember Spectral Mixture Analysis (MESMA) on airborne visible/infrared imaging spectrometer (AVIRIS) imagery from June 2013. Imagery was then degraded to Landsat spectral resolution and reclassified for comparison. Results with the AVIRIS imagery show an overall accuracy of 69.0% using MESMA and 89.4% using CDA with nine out of fourteen crop species showing user and producer errors under ten percent. Lower accuracy was found for OLI data. This research illustrates great potential for field-level crop mapping with imaging spectrometry.

  19. Hydrogeologic framework of Antelope Valley and Bedell Flat, Washoe County, west-central Nevada

    USGS Publications Warehouse

    Berger, D.L.; Ponce, D.A.; Ross, W.C.

    2001-01-01

    Description of the hydrogeologic framework of Antelope Valley and Bedell Flat in west-central Nevada adds to the general knowledge of regional ground-water flow north of the Reno-Sparks metropolitan area. The hydrogeologic framework is defined by the rocks and deposits that transmit ground water or impede its movement and by the combined thickness of Cenozoic deposits. When data are lacking about the subsurface geology of an area, geophysical methods can be used to provide additional information. In this study, gravimetric and seismic-refraction methods were used to infer the form of structural features and to estimate the thickness of Cenozoic deposits in each of the two valleys. In Antelope Valley, the thickness of these deposits probably does not exceed about 300 feet, suggesting that ground-water storage in the basin-fill aquifer is limited. Beneath Bedell Flat is an elongated, northeast-trending structural depression in the pre-Cenozoic basement; the maximum thickness of Cenozoic deposits is about 2,500 feet beneath the south-central part of the valley. Shallow ground water in the northwest corner of Bedell Flat may be a result of decreasing depth to the pre-Cenozoic basement.

  20. Descriptions and chemical analyses for selected wells in the Central Sacramento Valley, California

    USGS Publications Warehouse

    Fogelman, Ronald P.

    1976-01-01

    The Sacramento Valley occupies the northern one-third of the Great Central Valley of California. The study area of this report includes about 1,200 square miles (3,100 square kilometers) adjacent to the Sacramento River from Knights Landing to Los Molinos, in parts of Yolo, Sutter, Colusa, Glenn, Butte, and Tehama Counties. Between April and August 1975, 559 wells were canvassed, and during September and October 1975, water samples were collected for chemical analysis from 209 of these wells. Field determinations of alkalinity, conductance, pH , and temperature were made on the site at the time of sampling. Samples were prepared in the field for shipment and analysis for individual constituents at the Geological Survey Central Laboratory, Salt Lake City, Utah. Descriptive data for water wells are listed, chemical data are tabulated, and the location of wells is shown on maps. (Woodard-USGS)

  1. The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields (2011 Final)

    EPA Science Inventory

    EPA announced the availability of the final report, The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields. This report assesses the state of the science on the environmental impacts of mountaintop mines and valley ...

  2. Vivid valleys, pallid peaks? Hypsometric variations and rural-urban land change in the Central Peruvian Andes.

    PubMed

    Haller, Andreas

    2012-11-01

    What happens to the land cover within the hinterland's altitudinal belts while Central Andean cities are undergoing globalization and urban restructuring? What conclusions can be drawn about changes in human land use? By incorporating a regional altitudinal zonation model, direct field observations and GIS analyses of remotely sensed long term data, the present study examines these questions using the example of Huancayo Metropolitano - an emerging Peruvian mountain city of 420,000 inhabitants, situated at 3260 m asl in the Mantaro Valley. The study's results indicate that rapid urban growth during the late 1980s and early 1990s was followed by the agricultural intensification and peri-urban condominization at the valley floor (quechua) - since the beginning of Peru's neoliberal era. Moreover, regarding the adjoining steep slopes (suni) and subsequent grassland ecosystems (puna), the research output presents land cover change trajectories that clearly show an expansion of human land use, such as reforestation for wood production and range burning for livestock grazing, even at high altitudes - despite rural-urban migration trends and contrary to several results of extra-Andean studies. Consequently, rural-urban planners and policy makers are challenged to focus on the manifold impacts of globalization on human land use - at all altitudinal belts of the Andean city's hinterland: toward sustainable mountain development that bridges the social and physical gaps - from the bottom up.

  3. Vivid valleys, pallid peaks? Hypsometric variations and rural–urban land change in the Central Peruvian Andes

    PubMed Central

    Haller, Andreas

    2012-01-01

    What happens to the land cover within the hinterland's altitudinal belts while Central Andean cities are undergoing globalization and urban restructuring? What conclusions can be drawn about changes in human land use? By incorporating a regional altitudinal zonation model, direct field observations and GIS analyses of remotely sensed long term data, the present study examines these questions using the example of Huancayo Metropolitano – an emerging Peruvian mountain city of 420,000 inhabitants, situated at 3260 m asl in the Mantaro Valley. The study's results indicate that rapid urban growth during the late 1980s and early 1990s was followed by the agricultural intensification and peri-urban condominization at the valley floor (quechua) – since the beginning of Peru's neoliberal era. Moreover, regarding the adjoining steep slopes (suni) and subsequent grassland ecosystems (puna), the research output presents land cover change trajectories that clearly show an expansion of human land use, such as reforestation for wood production and range burning for livestock grazing, even at high altitudes – despite rural–urban migration trends and contrary to several results of extra-Andean studies. Consequently, rural–urban planners and policy makers are challenged to focus on the manifold impacts of globalization on human land use – at all altitudinal belts of the Andean city's hinterland: toward sustainable mountain development that bridges the social and physical gaps – from the bottom up. PMID:23564987

  4. Water budgets for major streams in the Central Valley, California, 1961-77

    USGS Publications Warehouse

    Mullen, J.R.; Nady, Paul

    1985-01-01

    A compilation of annual streamflow data for 20 major stream systems in the central Valley of California, for water years 1961-77, is presented. The water-budget tables list gaged and ungaged inflow from tributaries and canals, diversions, and gaged outflow. Theoretical outflow and gain or loss in a reach are computed. A schematic diagram and explanation of the data are provided for each water-budget table. (USGS)

  5. Integrated simulation of consumptive use and land subsidence in the Central Valley, California, for the past and for a future subject to urbanization and climate change

    USGS Publications Warehouse

    Hanson, Randall T.; Flint, Alan L.; Faunt, Claudia C.; Cayan, Daniel R.; Flint, Lorraine E.; Leake, Stanley A.; Schmid, Wolfgang

    2010-01-01

    Competition for water resources is growing throughout California, particularly in the Central Valley where about 20% of all groundwater used in the United States is consumed for agriculture and urban water supply. Continued agricultural use coupled with urban growth and potential climate change would result in continued depletion of groundwater storage and associated land subsidence throughout the Central Valley. For 1962-2003, an estimated 1,230 hectare meters (hm3) of water was withdrawn from fine-grained beds, resulting in more than three meters (m) of additional land subsidence locally. Linked physically-based, supply-constrained and emanddriven hydrologic models were used to simulate future hydrologic conditions under the A2 climate projection scenario that assumes continued "business as usual" greenhouse gas emissions. Results indicate an increased subsidence in the second half of the twenty-first century. Potential simulated land subsidence extends into urban areas and the eastern side of the valley where future surface-water deliveries may be depleted. 

  6. Revised magnitude-bound relation for the Wabash Valley seismic zone of the central United States

    USGS Publications Warehouse

    Olson, S.M.; Green, R.A.; Obermeier, S.F.

    2005-01-01

    Seismic hazard assessment in the central United States, and in particular the Wabash Valley seismic zone of Indiana-Illinois, frequently relies on empirical estimates of paleoearthquake magnitudes (M). In large part these estimates have been made using the magnitude-bound method. Existing region-specific magnitude-bound relations rely heavily on only a few historical earthquakes in the central United States and eastern Canada that induced reported liquefaction features. Recent seismological studies have suggested smaller magnitudes than previously presumed for some of these earthquakes, however, and other studies have reinterpreted site-to-source distances to liquefaction features associated with some of these earthquakes. In this paper, we re-examine historical earthquakes (M > ???5) that occurred in the central and eastern United States and eastern Canada; some of these earthquakes triggered liquefaction and others did not. Based on our findings, we reinterpret the region-specific magnitude-bound relation for the Wabash Valley. Using this revised magnitude-bound relation, we present magnitude estimates for four prehistoric earthquakes that occurred in the Wabash Valley seismic zone during Holocene time.

  7. Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada Mountains

    USGS Publications Warehouse

    Zabik, John M.; Seiber, James N.

    1993-01-01

    Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada mountains was assessed by collecting air- and wet-deposition samples during December, January, February, and March, 1990 to 1991. Large-scale spraying of these pesticides occurs during December and January to control insect infestations in valley orchards. Sampling sites were placed at 114- (base of the foothills), 533-, and 1920-m elevations. Samples acquired at these sites contained chlorpyrifos [phosphorothioic acid; 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl) ester], parathion [phosphorothioic acid, 0-0-diethylo-(4-nitrophenyl) ester], diazinon {phosphorothioic acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester} diazinonoxon {phosphoric acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester}, and paraoxon [phosphoric acid, 0,0-diethyl 0-(4-nitrophenyl) ester] in both air and wet deposition samples. Air concentrations of chloropyrifos, diazinon and parathion ranged from 13 to 13 000 pg/m3 at the base of the foothills. At 533-m air concentrations were below the limit of quantification (1.4 pg/m3) to 83 pg/m3 and at 1920 m concentrations were below the limit of quantification. Concentrations in wet deposition varied with distance and elevation from the Central Valley. Rainwater concentrations at the base of the foot hills ranged from 16 to 7600 pg/mL. At 533-m rain and snow water concentrations ranged from below the limit of quantification (1.3 pg/mL) to 140 pg/mL and at 1920 m concentrations ranged from below the limit of quantification to 48 pg/mL. These findings indicate that atmospheric transport of pesticides applied in the valley to the Sierra Nevada mountains is occurring, but the levels decrease as distance and elevation increase from the valley floor.

  8. Mechanisms Contributing to Suppressed Precipitation in Mt. Hua of Central China. Part I: Mountain Valley Circulation

    SciTech Connect

    Yang, Yan; Fan, Jiwen; Leung, L. Ruby; Zhao, Chun; Li, Zhanqing; Rosenfeld, Daniel

    2016-03-01

    Significant reduction in precipitation in the past decades has been documented over many mountain ranges such as those in central and eastern China. Consistent with the increase of air pollution in these regions, it has been argued that the precipitation trend is linked to aerosol microphysical effect on suppressing warm rain. Rigorous quantitative investigations on the reasons responsible for the precipitation reduction are lacking. Here in this study, we employed an improved Weather Research and Forecasting (WRF) model with online coupled chemistry (WRF-Chem) and conducted simulations at the convection-permitting scale to explore the major mechanisms governing changes in precipitation from orographic clouds in the Mountain (Mt.) Hua area in Central China. We find that anthropogenic pollution contributes to a ~ 40% reduction of precipitation over Mt. Hua during the one-month summer time period. The reduction is mainly associated with precipitation events associated with valleymountain circulation and a mesoscale cold front event. In this Part I paper, we scrutinize the mechanism leading to significant reduction for the cases associated with valley-mountain circulation. We find that the valley breeze is weakened by aerosols due to absorbing aerosol induced warming aloft and cooling near the surface as a result of aerosol-radiation interaction (ARI). The weakened valley breeze along with reduced water vapor in the valley due to reduced evapotranspiration as a result of surface cooling significantly reduce the transport of water vapor from the valley to mountain and the relative humidity over the mountain, thus suppressing convection and precipitation in the mountain.

  9. Influence of Organic Agriculture on the Net Greenhouse Effect in the Red River Valley, Minnesota

    NASA Astrophysics Data System (ADS)

    Phillips, R. L.

    2004-12-01

    Fluxes for the suite of biologically-produced greenhouse gases (CH4, N2O and CO2) are strongly influenced by agriculture, yet the influence of organic agriculture on all three gases, which comprise the net greenhouse effect (GHE), is not clear in the context of large-scale agricultural production. Greenhouse gas mitigation potential will depend upon the net balance for all three gases [GHE balance (CO2 equiv.)= CO2 flux+ 23CH4flux + 296N2Oflux]. On-farm, field-scale experiments were performed to test the hypothesis that the net GHE at the soil-atmosphere interface is reduced under organic wheat production, compared with conventional, and that effects vary inter-seasonally. Trace gas fluxes were measured at the soil-atmosphere interface for organic and conventional wheat farms in the Red River Valley, Minnesota, one of the most productive agricultural regions in the US. We utilized 40-60 ha field pairs planted with hard red spring wheat (Triticum aestivum L.). Treatment pairs were located 6km apart and consisted of fields continuously cropped for wheat/soybean/sugar beet production for over 20 yr. Ten random, permanent points were generated for each 8.1 ha sub-plot nested inside each field. Each field pair was similar with respect to crop, climate, cultivation history, tillage, rotation, soil texture, pH, macronutrients, bulk density, and water holding capacity. Differences between treatments for the last five years were soil amendments (compost or urea) and herbicide/fungicide application versus mechanical weed control. We collected gas fluxes at each of the 41 points from April (wheat emergence) until the end of July (maturity) to determine the hourly and seasonally integrated net GHE for each management practice, given similar soil/plant/climatic conditions. Moreover, we analyzed inter-seasonal variability to determine the relationship between wheat phenology and flux under field conditions for soil temperature and moisture (water-filled pore space). The net GHE

  10. Mapping agricultural landscapes and characterizing adaptive capacity in Central America

    NASA Astrophysics Data System (ADS)

    Holland, M. B.; Imbach, P. A.; Bouroncle, C.; Donatti, C.; Leguia, E.; Martinez, M.; Medellin, C.; Saborio-Rodriguez, M.; Shamer, S.; Zamora, J.

    2013-12-01

    One of the key challenges in developing adaptation strategies for smallholder farmers in developing countries is that of a data-poor environment, where spatially-explicit information about where the most vulnerable smallholder communities are located is lacking. Developing countries tend to lack consistent and reliable maps on agricultural land use, and have limited information available on smallholder adaptive capacity. We developed a novel participatory and expert mapping process to overcome these barriers and develop detailed national-scale maps that allow for a characterization of unique agricultural landscapes based on profiles of adaptive capacity for smallholder agriculture in each area. This research focuses specifically on the Central American nations of Costa Rica, Guatemala, and Honduras, where our focus is on coffee and basic grains as the two main cropping systems. Here we present the methodology and results of a series of in-depth interviews and participatory mapping sessions with experts working within the broader agricultural sector in each country. We held individual interviews and mapping sessions with approximately thirty experts from each country, and used a detailed survey instrument for each mapping session to both spatially identify distinct agricultural landscapes, and to further characterize each area based on specific farm practices and social context. The survey also included a series of questions to help us assess the relative adaptive capacity of smallholder agriculture within each landscape. After all expert mapping sessions were completed in each country we convened an expert group to assist in both validating and refining the set of landscapes already defined. We developed a characterization of adaptive capacity by aggregating indicators into main assets-based criteria (e.g. land tenure, access to credit, access to technical assistance, sustainable farm practices) derived from further expert weighting of indicators through an online

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

    USGS Publications Warehouse

    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

  12. Organochlorine Pesticide Residues in Plankton, Rangsit Agricultural Area, Central Thailand

    PubMed Central

    Siriwong, W.; Thirakhupt, K.; Sitticharoenchai, D.; Borjan, M.; Robson, M.

    2014-01-01

    Few studies have investigated organochlorine pesticide residue content in freshwater plankton communities in Thailand. As a result, this study looks to examine the concentration of organochlorine pesticide residues in plankton collected from Khlong 7 (canal) at Rangsit agricultural area, central Thailand from June 2006 to February 2007. The results from this study show that plankton communities were composed of microphytoplankton, microzooplankton, and mesozooplankton. The average method recoveries varied from 84% to 103% with a relative standard deviation between 0.20% and 3.72%. The concentrations of organochlorine pesticide residues during a one-year-period were in the range of 0.10–3.65 ng/g wet wt and contained DDT and derivatives > Σ endosulfan > Σ HCH > Σ heptachlor > aldrin and dieldrin > endrin and endrin aldehyde > methoxychlor, respectively. Moreover, the residues of Σ HCH, DDT and derivatives, and methoxychlor were higher during wet season than dry season (t-test, p ≤ 0.05). PMID:18777151

  13. Organochlorine pesticide residues in plankton, Rangsit agricultural area, central Thailand.

    PubMed

    Siriwong, W; Thirakhupt, K; Sitticharoenchai, D; Borjan, M; Robson, M

    2008-12-01

    Few studies have investigated organochlorine pesticide residue content in freshwater plankton communities in Thailand. As a result, this study looks to examine the concentration of organochlorine pesticide residues in plankton collected from Khlong 7 (canal) at Rangsit agricultural area, central Thailand from June 2006 to February 2007. The results from this study show that plankton communities were composed of microphytoplankton, microzooplankton, and mesozooplankton. The average method recoveries varied from 84% to 103% with a relative standard deviation between 0.20% and 3.72%. The concentrations of organochlorine pesticide residues during a one-year-period were in the range of 0.10-3.65 ng/g wet wt and contained DDT and derivatives > Sigma endosulfan > Sigma HCH > Sigma heptachlor > aldrin and dieldrin > endrin and endrin aldehyde > methoxychlor, respectively. Moreover, the residues of Sigma HCH, DDT and derivatives, and methoxychlor were higher during wet season than dry season (t-test, p

  14. InSAR deformation time series for an agricultural area in the San Luis Valley

    NASA Astrophysics Data System (ADS)

    Reeves, J. A.; Knight, R.; Zebker, H. A.; Schreüder, W. A.; Shanker, P.; Lauknes, T. R.

    2009-05-01

    The San Luis Valley (SLV) is an 8000 km2 region in southern Colorado that is home to a thriving agricultural economy. This valley is currently in a period of extreme drought, with county and state regulators struggling to develop appropriate management policies for both the surface water and the ground water. In 1998 the state of Colorado commissioned the Rio Grande Decision Support System to refine the hydogeologic characterization of the system, including the development of a MODFLOW finite difference model of groundwater flow. The main challenge in the SLV is acquiring sufficient data to characterize the spatially heterogeneous, time-varying behavior of the groundwater system. Here we apply the small baseline subset analysis (SBAS) interferometric radar (InSAR) technique to provide such data. InSAR techniques yield the deformation of Earth's surface at fine spatial resolution occurring between two satellite overflights, and SBAS permits solution for a time series of deformation maps. The measured deformation can be related to changes in the water table in underlying confined aquifers. The ability to map these changes, over time, in the SLV will provide critical information about the groundwater system. Historically, InSAR measurements have been difficult to make in agricultural areas. The change in cm-scale crop structure with time leads to signal decorrelation and the loss of useful information about surface deformation. The recently-developed SBAS method allows stable deformation estimates at certain ground points in an otherwise decorrelated time series of data. We applied this approach to data collected by the European Space Agency's ERS-1 and ERS-2 satellites over the western SLV from track 98 frame 2853 for the years 1992-2001. We used the Generic SAR (GSAR) SBAS software developed by Norut to produce time series deformation measurements for many positions across the entire SLV. We find that the 2000 km2 area captured in track 98 frame 2853 shows very high

  15. Runoff simulation in the Ferghana Valley (Central Asia) using conceptual hydrological HBV-light model

    NASA Astrophysics Data System (ADS)

    Radchenko, Iuliia; Breuer, Lutz; Forkutsa, Irina; Frede, Hans-Georg

    2013-04-01

    Glaciers and permafrost on the ranges of the Tien Shan mountain system are primary sources of water in the Ferghana Valley. The water artery of the valley is the Syr Darya River that is formed by confluence of the Naryn and Kara Darya rivers, which originate from the mountain glaciers of the Ak-Shyrak and the Ferghana ranges accordingly. The Ferghana Valley is densely populated and main activity of population is agriculture that heavily depends on irrigation especially in such arid region. The runoff reduction is projected in future due to global temperature rise and glacier shrinkage as a consequence. Therefore, it is essential to study climate change impact on water resources in the area both for ecological and economic aspects. The evaluation of comparative contribution of small upper catchments (n=24) with precipitation predominance in discharge and the large Naryn and Karadarya River basins, which are fed by glacial melt water, to the Fergana Valley water balance under current and future climatic conditions is general aim of the study. Appropriate understanding of the hydrological cycle under current climatic conditions is significant for prognosis of water resource availability in the future. Thus, conceptual hydrological HBV-light model was used for analysing of the water balance of the small upper catchments that surround the Ferghana Valley. Three trial catchments (the Kugart River basin, 1010 km²; the Kurshab River basin, 2010 km2; the Akbura River basin, 2260 km²) with relatively good temporal quality data were chosen to setup the model. Due to limitation of daily temperature data the MODAWEC weather generator, which converts monthly temperature data into daily based on correlation with rainfall, was tested and applied for the HBV-light model.

  16. Late Pleistocene deglaciation in the upper Gállego Valley, central Pyrenees

    NASA Astrophysics Data System (ADS)

    Palacios, David; de Andrés, Nuria; López-Moreno, Juan I.; García-Ruiz, José M.

    2015-05-01

    Deglaciation processes in the upper Gállego Valley, central-southern Pyrenees, were studied using geomorphological mapping and 36Cl cosmogenic dating of moraine and rock glacier boulders, as well as polished bedrock. Although the precise position of the Gállego Glacier during the global last glacial maximum is not known, there is evidence that ice tongues retreated to the headwaters, which caused subdivision of the main glacier into a number of individual glaciers prior to 17 ka. A range of ages (16 to 11 ka) was found among three tributary valleys within the general trend of deglaciation. The retreat rate to cirque was estimated to be relatively rapid (approximately 5 km per ka). The mapped glacial sedimentology and geomorphology appears to support the occurrence of multiple minor advances and retreats, or periods of stasis during the late deglaciation. Geomorphological and geological differences among the tributary valleys, and error estimates associated with the results obtained, prevented unambiguous correlations of the advances with the late Pleistocene cold periods. During the latter advances, small glaciers and rock glaciers developed close to the cirque headwalls, and co-occurred under the same climatic conditions. No evidence for Holocene re-advance was found for any of the three tributary valleys.

  17. The Costa Rican Central Valley Lavina Formation: Lahar or Debris Avalanche?

    NASA Astrophysics Data System (ADS)

    Hidalgo, P. J.; Alvarado Induni, G. E.; Linkimer, L.

    2005-12-01

    The Lavina Formation of the Central Valley of Costa Rica consists of lava blocks floating in a volcanic mud matrix. Different authors have interpreted this deposit genetically as a lahar or debris flow deposit. Based on geomorphologic, textural, and morphometric evidence, we conclude that the origin of this deposit is a debris avalanche event that transformed into a debris flow on its path down the valley. Using aerial photographs, many debris avalanche amphitheaters are found in the western sector of the Irazu volcanic complex. However, textural and morphometric characteristics of the deposit are consistent with the source of the sector collapse being located on the west flank of the Cabeza de Vaca volcano. Three-dimensional modeling of the Lavina Formation was done using data from 213 drill cores distributed along the Central Valley area. Maps of isopaches and isohipses of the roof and floor of this stratum were created. These allowed for qualification of morphometry of the stratigraphic surfaces, characterization of the paleoslopes, and quantification of the compacted deposit volume. The data derived form the isopach and isohipse contour maps indicate that abrupt changes in the thickness of the stratum are common. Also, it illustrates the morphological differences between the roof, elongated hills in the direction of the flux, and the floor of the stratum, smooth and uniform. The morphometric, geomorphologic, and textural evidence, were used to conclude that the Lavina deposit originated as a debris avalanche event in the Cabeza de Vaca Volcano. The debris avalanche was eventually fluidized into a debris flow that spread extensively (130 km2) along the Central Valley of Costa Rica.

  18. (Negative) Impacts of Intensive Agriculture in the Neighborhood of the National Park Lower Oder Valley

    NASA Astrophysics Data System (ADS)

    Chmieleski, Jana; Herrmann, Frank

    2014-05-01

    National Parks are areas of special interest with regard to biodiversity, development of wilderness but also water quality as well as socio-economic functions as education and recreation. Agricultural use is restricted to small parts of the area. But which problems arise from intensive agriculture directly outside of the National Park area? Referred to as water pollution and nutrient leaching trough groundwater pathways, shifting of nutrients via soil erosion there are a lot of problems arising and are increasing due to intensification of land use, for instance for bioenergy crops (maize). How this can be quali- and quantified? The German National Park Lower Oder Valley protects the floodplain and the riparian zone of the river Oder as well as old deciduous forest on the mineral plateau. The shape is elongated and narrow. The edge with non-protected is large. In the Northern part are industrial areas. Large areas more and more are used for bioenergy crops. This results in high nitrate and phosphorous concentrations in soil and interflow/groundwater. Often this water is gathered in drainage canals which end up in natural small waterways. Outside the National Park the waterways often are drains but inside the Park area they are (semi-)natural. These waterways are of high interest with redarding to nature conservation aspects - since they are in (very) good structural conditions (Water Frame Work evaluation). How to deal with this discrepancy? In order to quali- and quantify nutrient concentration and transport as well as to detect the change of vegetation and habitats in the whole National Park we set up an environmental observatory by installing transect measurements as well as point measurements.

  19. Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

    USGS Publications Warehouse

    Tumbusch, Mary L.; Plume, Russell W.

    2006-01-01

    The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

  20. Data for projected impacts of climate, urbanization, water management, and wetland restoration on waterbird habitat in California’s Central Valley

    USGS Publications Warehouse

    Matchett, Elliott L.; Fleskes, Joseph

    2017-01-01

    he Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there.  Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats.  Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial.  Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework.  Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario.  Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time.  After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years.  The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats.  This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning.  Results indicate that increased wetland

  1. Agricultural pesticide residues of farm runoff in the Okanagan Valley, British Columbia, Canada.

    PubMed

    Kuo, Jen-ni; Soon, Alicia Y; Garrett, Christine; Wan, Michael T K; Pasternak, John P

    2012-01-01

    The objectives of this study were to determine environmental occurrence and concentrations of selected currently-used-pesticides and some transformation products in agricultural farms in the Okanagan Valley (OKV), and to conduct a simple risk assessment of environmental pesticides levels detected in OKV on non-target aquatic organisms. The OKV is the tree fruit country of the Province of British Columbia where considerable amount of pesticides are applied annually. Water, sediment and soil samples were collected at eleven sites in early June and late September following rainfall events and/or extended periods of irrigation from drainage ditches and/or from small streams. Undisturbed reference sites were also sampled. Study results showed that forty of the eighty chemicals analyzed, including organochlorine, nitrogen-containing and organophosphate pesticides commonly used for OKV crops, were detected in runoff and small stream water samples. Among which, endosulfan-sulfate was the most frequently detected chemical. Also, azinophos-methyl (0.699-25.5 ng/L), diazinon (0.088-214 ng/L) exceeded, and α-, β- endosulfan, endosulfan sulphate approached the guidelines for the protection of aquatic life.

  2. Late Quaternary tectonic landforms and fluvial aggradation in the Saryu River valley: Central Kumaun Himalaya

    NASA Astrophysics Data System (ADS)

    Kothyari, Girish Ch.; Luirei, Khayingshing

    2016-09-01

    The present study has been carried out with special emphasis on the aggradational landforms to explain the spatial and temporal variability in phases of aggradation/incision in response to tectonic activity during the late Quaternary in the Saryu River valley in central Kumaun Himalaya. The valley has preserved cut-and-fill terraces with thick alluvial cover, debris flow terraces, and bedrock strath terraces that provide signatures of tectonic activity and climate. Morphostratigraphy of the terraces reveals that the oldest landforms preserved south of the Main Central Thrust, the fluvial modified debris flow terraces, were developed between 30 and 45 ka. The major phase of valley fill is dated between 14 and 22 ka. The youngest phase of aggradation is dated at early and mid-Holocene (9-3 ka). Following this, several phases of accelerated incision/erosion owing to an increase in uplift rate occurred, as evident from the strath terraces. Seven major phases of bedrock incision/uplift have been estimated during 44 ka (3.34 mm/year), 35 ka (1.84 mm/year), 15 ka (0.91 mm/year), 14 ka (0.83 mm/year), 9 ka (1.75 mm/year), 7 ka (5.38 mm/year), and around 3 ka (4.4 mm/year) from the strath terraces near major thrusts. We postulate that between 9 and 3 ka the terrain witnessed relatively enhanced surface uplift (2-5 mm/year).

  3. Predicted pH at the domestic and public supply drinking water depths, Central Valley, California

    USGS Publications Warehouse

    Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, Jo Ann M.

    2017-03-08

    This scientific investigations map is a product of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project modeling and mapping team. The prediction grids depicted in this map are of continuous pH and are intended to provide an understanding of groundwater-quality conditions at the domestic and public supply drinking water zones in the groundwater of the Central Valley of California. The chemical quality of groundwater and the fate of many contaminants is often influenced by pH in all aquifers. These grids are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to pH. In this work, the median well depth categorized as domestic supply was 30 meters below land surface, and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically boosted regression trees (BRT) with a Gaussian error distribution within a statistical learning framework within the computing framework of R (http://www.r-project.org/). The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1,337 wells and was compiled from two sources: USGS National Water Information System (NWIS) database (all data are publicly available from the USGS: http://waterdata.usgs.gov/ca/nwis/nwis) and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: http://www.waterboards.ca.gov/gama/geotracker_gama.shtml). Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993–2014 was used. A total of 1,003 wells (training dataset) were used to train the BRT

  4. Modeling The Evolution Of A Regional Aquifer System With The California Central Valley Groundwater-Surface Water Simulation Model (C2VSIM)

    NASA Astrophysics Data System (ADS)

    Brush, C. F.; Dogrul, E. C.; Kadir, T. N.; Moncrief, M. R.; Shultz, S.; Tonkin, M.; Wendell, D.

    2006-12-01

    The finite element application IWFM has been used to develop an integrated groundwater-surface water model for California's Central Valley, an area of ~50,000 km2, to simulate the evolution of the groundwater flow system and historical groundwater-surface water interactions on a monthly time step from October 1921 to September 2003. The Central Valley's hydrologic system changed significantly during this period. Prior to 1920, most surface water flowed unimpeded from source areas in the mountains surrounding the Central Valley through the Sacramento-San Joaquin Delta to the Pacific Ocean, and groundwater largely flowed from recharge areas on the valley rim to discharge as evapotransipration in extensive marshes along the valley's axis. Rapid agricultural development led to increases in groundwater pumping from ~0.5 km3/yr in the early 1920's to 13-18 km3/yr in the 1940's to 1970's, resulting in strong vertical head gradients, significant head declines throughout the valley, and subsidence of >0.3 m over an area of 13,000 km2. Construction of numerous dams and development of an extensive surface water delivery network after 1950 altered the surface water flow regime and reduced groundwater pumping to the current ~10 km3/yr, increasing net recharge and leading to local head gradient reversals and water level recoveries. A model calibrated to the range of historical flow regimes in the Central Valley will provide robust estimations of stream-groundwater interactions for a range of projected future scenarios. C2VSIM uses the IWFM application to simulate a 3-D finite element groundwater flow process dynamically coupled with 1-D land surface, stream flow, lake and unsaturated zone processes. The groundwater flow system is represented with three layers each having 1393 elements. Land surface processes are simulated using 21 subregions corresponding to California DWR water-supply planning areas. The surface-water network is simulated using 431 stream nodes representing 72

  5. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    NASA Astrophysics Data System (ADS)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  6. Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California's Central Valley

    USGS Publications Warehouse

    Ackerman, Joshua T.; Miles, A. Keith; Eagles-Smith, Collin A.

    2010-01-01

    We examined methylmercury (MeHg) bioavailability in four of the most predominant wetland habitats in California's Central Valley agricultural region during the spring and summer: white rice, wild rice, permanent wetlands, and shallowly-flooded fallow fields. We sampled MeHg and total mercury (THg) concentrations in two aquatic macroinvertebrate taxa at the inlets, centers, and outlets of four replicated wetland habitats (8 wetlands total) during two time periods bounding the rice growing season and corresponding to flood-up and pre-harvest (96 total samples). In general, THg concentrations (mean ± standard error) in Notonectidae (Notonecta, back swimmers; 1.18 ± 0.08 µg g− 1 dry weight [dw]) were higher than in Corixidae (Corisella, water boatmen; 0.89 ± 0.06 µg g− 1 dw, MeHg: 0.74 ± 0.05 µg g− 1 dw). MeHg concentrations were correlated with THg concentrations in Corixidae (R2 = 0.80) and 88% of THg was in the MeHg form. Wetland habitat type had an important influence on THg concentrations in aquatic invertebrates, but this effect depended on the sampling time period and taxa. In particular, THg concentrations in Notonectidae, but not Corixidae, were higher in permanent wetlands than in white rice, wild rice, or shallowly-flooded fallow fields. THg concentrations in Notonectidae were higher at the end of the rice growing season than near the time of flood-up, whereas THg concentrations in Corixidae did not differ between time periods. The effect of wetland habitat type was more prevalent near the end of the rice growing season, when Notonectidae THg concentrations were highest in permanent wetlands. Additionally, invertebrate THg concentrations were higher at water outlets than at inlets of wetlands. Our results indicate that although invertebrate THg concentrations increased from the time of flood-up to draw-down of wetlands, temporarily flooded habitats such as white rice, wild rice, and shallowly-flooded fallow fields did not

  7. Impact of Sustainable Agriculture on Secondary School Agricultural Education Teachers and Programs in the North Central Region.

    ERIC Educational Resources Information Center

    Agbaje, Kehinde Aderemi Ajaiyeoba; Martin, Robert A.; Williams, David L.

    2001-01-01

    Responses from 298 of 600 secondary agriculture teachers in north central United States revealed limited impact of sustainable agriculture. Most teachers had neutral perceptions; a moderate number taught it, but not from a systems perspective. However, related agronomy topics were taught, providing a possible foundation for future inclusion of…

  8. Adapting to Climate Variability and Change: Experiences from Cereal-Based Farming in the Central Rift and Kobo Valleys, Ethiopia

    NASA Astrophysics Data System (ADS)

    Kassie, Belay Tseganeh; Hengsdijk, Huib; Rötter, Reimund; Kahiluoto, Helena; Asseng, Senthold; Van Ittersum, Martin

    2013-11-01

    Small-holder farmers in Ethiopia are facing several climate related hazards, in particular highly variable rainfall with severe droughts which can have devastating effects on their livelihoods. Projected changes in climate are expected to aggravate the existing challenges. This study examines farmer perceptions on current climate variability and long-term changes, current adaptive strategies, and potential barriers for successful further adaptation in two case study regions—the Central Rift Valley (CRV) and Kobo Valley. The study was based on a household questionnaire, interviews with key stakeholders, and focus group discussions. The result revealed that about 99 % of the respondents at the CRV and 96 % at the Kobo Valley perceived an increase in temperature and 94 % at CRV and 91 % at the Kobo Valley perceived a decrease in rainfall over the last 20-30 years. Inter-annual and intraseasonal rainfall variability also has increased according to the farmers. The observed climate data (1977-2009) also showed an increasing trend in temperature and high inter-annual and intra-seasonal rainfall variability. In contrast to farmers’ perceptions of a decrease in rainfall totals, observed rainfall data showed no statistically significant decline. The interaction among various bio-physical and socio-economic factors, changes in rainfall intensity and reduced water available to crops due to increased hot spells, may have influenced the perception of farmers with respect to rainfall trends. In recent decades, farmers in both the CRV and Kobo have changed farming practices to adapt to perceived climate change and variability, for example, through crop and variety choice, adjustment of cropping calendar, and in situ moisture conservation. These relatively low-cost changes in farm practices were within the limited adaptation capacity of farmers, which may be insufficient to deal with the impacts of future climate change. Anticipated climate change is expected to impose new

  9. Reclaiming agricultural drainage water with nanofiltration membranes: Imperial Valley, California, USA

    USGS Publications Warehouse

    Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,

    2003-01-01

    We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse

  10. The cultural and chronological context of early Holocene maize and squash domestication in the Central Balsas River Valley, Mexico

    PubMed Central

    Ranere, Anthony J.; Piperno, Dolores R.; Holst, Irene; Dickau, Ruth; Iriarte, José

    2009-01-01

    Molecular evidence indicates that the wild ancestor of maize is presently native to the seasonally dry tropical forest of the Central Balsas watershed in southwestern Mexico. We report here on archaeological investigations in a region of the Central Balsas located near the Iguala Valley in Guerrero state that show for the first time a long sequence of human occupation and plant exploitation reaching back to the early Holocene. One of the sites excavated, the Xihuatoxtla Shelter, contains well-stratified deposits and a stone tool assemblage of bifacially flaked points, simple flake tools, and numerous handstones and milling stone bases radiocarbon dated to at least 8700 calendrical years B.P. As reported in a companion paper (Piperno DR, et al., in this issue of PNAS), starch grain and phytolith residues from the ground and chipped stone tools, plus phytoliths from directly associated sediments, provide evidence for maize (Zea mays L.) and domesticated squash (Cucurbita spp.) in contexts contemporaneous with and stratigraphically below the 8700 calendrical years B.P. date. The radiocarbon determinations, stratigraphic integrity of Xihuatoxtla's deposits, and characteristics of the stone tool assemblages associated with the maize and squash remains all indicate that these plants were early Holocene domesticates. Early agriculture in this region of Mexico appears to have involved small groups of cultivators who were shifting their settlements seasonally and engaging in a variety of subsistence pursuits. PMID:19307573

  11. The cultural and chronological context of early Holocene maize and squash domestication in the Central Balsas River Valley, Mexico.

    PubMed

    Ranere, Anthony J; Piperno, Dolores R; Holst, Irene; Dickau, Ruth; Iriarte, José

    2009-03-31

    Molecular evidence indicates that the wild ancestor of maize is presently native to the seasonally dry tropical forest of the Central Balsas watershed in southwestern Mexico. We report here on archaeological investigations in a region of the Central Balsas located near the Iguala Valley in Guerrero state that show for the first time a long sequence of human occupation and plant exploitation reaching back to the early Holocene. One of the sites excavated, the Xihuatoxtla Shelter, contains well-stratified deposits and a stone tool assemblage of bifacially flaked points, simple flake tools, and numerous handstones and milling stone bases radiocarbon dated to at least 8700 calendrical years B.P. As reported in a companion paper (Piperno DR, et al., in this issue of PNAS), starch grain and phytolith residues from the ground and chipped stone tools, plus phytoliths from directly associated sediments, provide evidence for maize (Zea mays L.) and domesticated squash (Cucurbita spp.) in contexts contemporaneous with and stratigraphically below the 8700 calendrical years B.P. date. The radiocarbon determinations, stratigraphic integrity of Xihuatoxtla's deposits, and characteristics of the stone tool assemblages associated with the maize and squash remains all indicate that these plants were early Holocene domesticates. Early agriculture in this region of Mexico appears to have involved small groups of cultivators who were shifting their settlements seasonally and engaging in a variety of subsistence pursuits.

  12. Pulmonary paragonimiasis in Southeast Asians living in the central San Joaquin Valley.

    PubMed Central

    Yee, B.; Hsu, J. I.; Favour, C. B.; Lohne, E.

    1992-01-01

    We describe four cases of pulmonary paragonimiasis in Southeast Asians who emigrated to the central San Joaquin Valley of California. Physicians should be alerted to the possibility of this disease in Asian patients with hemoptysis and pulmonary infiltrates. Paragonimiasis can masquerade as pulmonary tuberculosis, especially in patients from areas that are endemic for both the parasite and the tubercle bacillus. The ease and safety with which this infection can be treated, in contrast to tuberculosis, reiterates the importance of diagnosing this lung fluke when it is present. Images PMID:1574893

  13. Importance of wetland landscape structure to shorebirds wintering in an agricultural valley

    USGS Publications Warehouse

    Taft, Oriane W.; Haig, Susan M.

    2006-01-01

    Only recently has the influence of landscape structure on habitat use been a research focus in wetland systems. During non-breeding periods when food can be locally limited, wetland spatial pattern across a landscape may be of great importance in determining wetland use. We studied the influence of landscape structure on abundances of wintering Dunlin (Calidris alpina) and Killdeer (Charadrius vociferus) observed on wetlands in the agricultural Willamette Valley of Oregon, USA, during two winters (1999a??2000, 2000a??2001) of differing rainfall. We examined (1) shorebird use within a sample of 100 km2 regions differing in landscape structure (hectares of shorebird habitat [wet, unvegetated]) and (2) use of sites differing in landscape context (area of shorebird habitat within a species-defined radius). For use of sites, we also assessed the influence of two local characteristics: percent of soil exposed and area of wet habitat. We analyzed data using linear regression and information-theoretic modeling. During the dry winter (2000a??2001), Dunlin were attracted to regions with more wetland habitat and their abundances at sites increased with greater area of shorebird habitat within both the site and the surrounding landscape. In contrast, Dunlin abundances at sites were related to availability of habitat at only a local scale during the wet winter (1999a??2000). Regional habitat availability was of little importance in predicting Killdeer distributions, and Killdeer site use appeared unrelated to habitat distributions at both landscape and local scales. Results suggest prioritizing sites for conservation that are located in areas with high wetland coverage.

  14. Geomorphological analysis of the Lower Tagus Valley Fault Zone, Central Portugal.

    NASA Astrophysics Data System (ADS)

    Canora-Catalan, Carolina; Besana-Ostman, Glenda; Vilanova, Susana; Fonseca, Joao; Pinto, Luis; Domingues, Ana; Narciso, Joao; Pinheiro, Patricia

    2013-04-01

    The Lower Tagus Valley Fault Zone (LTVFZ) is a northeast-southwest trending tectonic structure located within the Lower Tagus Valley (LTV), in central Portugal associated with at least two historical events: the 1909 Mw 6.0-6.2 Benavente earthquake and the 1531 Mw 6.9 earthquake. Recent investigations indicate that the relatively linear valley associated with the Lower Tagus River is controlled by active faults in varying geometry and slip rates. Based on mapped traces, LTVFZ is about 80 kilometers long and transects Miocene to late Quaternary deposit. The east and west strands of the fault zone may have different level of activity based on the variable clarity of mapped morphological expressions. In this work, new fault strands were identified using aerial photos on eastern side of LTV. These eastern faults has a trend that almost parallel those active traces previously mapped by Besana-Ostman et al., 2012 on the western side of the valley. The newly-mapped faults has left-lateral strike-slip movements and can be separated into two segments based on the kinematic indicators like offsets on river, ridges, and valley together with fluvial terraces displacements. Until this study, no Holocene fault scarps have been identified on the eastern portion of the LTV. Quaternary activity of faults can be assessed by the evaluation of morphometric indexes. In case of LTVFZ, the most characteristic landforms are fault-generated mountain fronts and valleys where the mountain front sinuosity index Smf is measured for fault activity evaluation. Through this morphometric index, mountain fronts are classified into Class I (Smf 1-1.4); active, Class II (Smf 1.4-2.5); intermediate, and Class III (Smf >2.5); inactive. In this paper, the Smf is calculated for the western and eastern sides of LTV as 1.3 and 1.8, respectively. These Smf values indicate that the western mountain front of the LTV corresponds to Class I while the eastern mountain front is Class II. However, considering the

  15. Late Cenozoic stratigraphy and structure of the western margin of the central San Joaquin Valley, California

    USGS Publications Warehouse

    Lettis, William R.

    1982-01-01

    Late Cenozoic Stratigraphy Late Cenozoic deposits in the west-central San Joaquin Valley and adjacent foothills of the Diablo Range consist mainly of unconsolidated, poorly-sorted to well-sorted gravel, sand, silt and clay derived primarily from the Diablo Range and secondarily from the Sierra Nevada. Sedimentary structures, such as channeled contacts, laminated bedding, cross-stratification and clast-imbrication indicate that most of the deposits were transported and laid down by running water. These deposits are described and their facies relationships are illustrated in the 'Late Cenozoic Stratigraphy' section of this report (see Figures 17, and 26, and Table 9). Sediment shed from the Diablo Range accumulated primarily as a complex of coalescing alluvial fans on the piedmont slope of a San Joaquin Valley that at one time extended across the foothill belt to the present margin of the central Diablo Range; and as local fills within stream valleys of the Diablo Range foothills tributary to the San Joaquin Valley. These deposits are well exposed in Interstate-5 roadcuts, California Aqueduct and Delta-Mendota canal cuts, and stream banks along the many ephemeral and intermittent streams draining the Diablo Range. Sediment derived from the Sierra Nevada is confined primarily to the floodbasin of the San Joaquin Valley. It includes arkosic riverine and floodbasin deposits from the San Joaquin River and associated sloughs, as well as local ephemeral and perennial pond, swamp, oxbow-lake and lake deposits. These deposits are well-exposed in stream banks of the San Joaquin River and a few of the larger sloughs such as Salt Slough, Mud Slough and Kings Slough. Well-sorted, fine- and medium-grained, quartzose, cross-bedded sand, presumably derived from the Sierra Nevada, locally interfinger with or underlie fine-grained Coast Range alluvial-fan deposits. The sand probably originated by eolian reworking of Sierran alluvium from the floodbasin of the lower San Joaquin River

  16. Health risk in agricultural villages practicing wastewater irrigation in central Mexico: perspectives for protection.

    PubMed

    Cifuentes, E; Blumenthal, U; Ruiz-Palacios, G; Bennett, S; Quigley, M

    2000-01-01

    9,435 individuals participated in a cross-sectional survey in the irrigation districts of the Mezquital Valley (central Mexico). Exposure groups were: 848 households irrigating with untreated wastewater, 544 households irrigating with the effluent from a series of interconnected reservoirs, and 928 households farming with natural rainfall. The unit of analysis was the individual, and the health outcomes included diarrhoeal diseases and Ascaris lumbricoides infection. Water quality was assessed using faecal coliforms (FC) and nematode eggs, as suggested by (WHO, 1989) for the safe use of wastewater in agriculture. Children from households irrigating with untreated wastewater (10(8) FC/100 mL and 135 nematode eggs/L) had a 33% higher risk of diarrhoeal diseases and a fivefold increase in risk of A. lumbricoides infection (OR = 5.71) compared to children from the control group, farming with rainfall. The risk of A. lumbricoides infection in older individuals was even higher (OR = 13.18). The final analysis showed that drinking unboiled water and cultivating vegetables crops were both associated with a higher risk of diarrheal diseases (OR = 1.45 and 2.00); individuals infected with A. lumbricoides infection came mostly from landless households with poorer dwellings and low standards of sanitation (OR = 2.20, 2.23, 1.72 and 1.43, respectively). These results are discussed in the context of health protection measures and policy recommendations.

  17. Paleoseismic results of the east strand of the Lower Tagus Valley Fault Zone, Central Portugal.

    NASA Astrophysics Data System (ADS)

    Canora, Carolina; Vilanova, Susana; Besana-Ostman, Glenda; Heleno, Sandra; Fonseca, Joao; Domingues, Ana; Pinheiro, Patricia; Pinto, Luis

    2014-05-01

    The Lower Tagus Valley Fault Zone (LTVFZ) is a northeast-southwest trending tectonic structure located within the Lower Tagus Valley (LTV), in central Portugal associated with at least two historical events: the 1909 Mw 6.0-6.2 Benavente earthquake and the 1531 Mw 6.9 earthquake. Recent investigations indicate that the relatively linear valley associated with the Lower Tagus River is controlled by active faults in varying geometry and slip rates. Based on mapped traces, LTVFZ is about 80 kilometers long and transects Miocene to Holocene deposit. The east and west strands of the fault zone may have different level of activity based on the variable clarity of mapped morphological expressions. In recent studies new fault strands were identified using aerial photos and field survey on eastern side of LTV. These eastern faults have a trend that almost parallel those active traces previously mapped by Besana-Ostman et al., 2012 on the western side of the valley. Quaternary activity of this fault deforms fluvial terraces and produces morphological features related to left-lateral strike-slip movement like river offsets. In this work we present the results of the first paleoseismic analysis carried out on this strand of the fault. Trenching studies shows that surface rupture events have occurred affecting Tagus fluvial terraces. The geometry of faulting exposed in the trench provides valuable insights into the kinematics of the fault, and provides a preliminary minimum net slip rate. New relative ages of the deformation are established on preliminary trenching results, and recurrence intervals will be determined upon receipt of results of sample processing for C14 dating. The aim of this work is to contribute with new data to parameterize the paleoseismic activity of this active fault in order to be included in the future seismic hazard assessments. Further studies are proposed and underway to characterize the LTVFZ, including high-resolution LIDAR images analysis, more

  18. Depositional environments and sedimentary tectonics of subsurface Cotton Valley group (upper Jurassic), west-central Mississippi

    SciTech Connect

    Sydboten, B.D. Jr.; Bowen, R.L.

    1987-09-01

    Study of data from 65 selected wells in a 6-county area (about 60 by 60 mi) north and west of Jackson, Mississippi, discloses that Cotton Valley strata, now within the axial trough of the Mississippi embayment, display thickness variations which demonstrate that Late Jurassic sedimentation was strongly controlled by maximum subsidence along the same trough axis. Examination of well logs, other records, and cutting sets from 38 wells has resulted in preparation of dip and strike cross sections that permit information definition of lower, middle, and upper parts of the Cotton Valley Group throughout the area evaluated. Within these lithostratigraphic diversions, lithofacies are discriminable that represent alluvial, upper delta plain, lower delta plain, and prodeltaic environments. These facies display a general variation from coarse, commonly red, oxidized sediments on the north and east, to mudrocks, locally calcareous and carbonaceous, on the southwest. Within the Cotton Valley Group examined, two persistent clastic lobes demonstrate relative environmental stability while deposits ranging in thickness from 1500 ft (northwestern corner of study area) to 4500 ft (axial depocenter on the south) accumulated. During Cotton Valley deposition, west-central Mississippi was the site of a two-toed birdfoot delta within which lignites were deposited. Major sediment supply was from the east and north; a minor source was to the northwest (Ouachita-Ozarks). Irregulatories in both rates of supply of clastics and of shelf subsidence permitted intermittent shallow, clear-water, marine incursions from the south during which thin carbonate beds were deposited, interfingering with the clastics. Thus, potential source and host rocks for hydrocarbon traps are closely associated, for thick, organic-rich, interlobate mudrocks pass laterally and vertically into fluvial sands of the delta lobes.

  19. Spatial and seasonal variability of base flow in the Verde Valley, central Arizona, 2007 and 2011

    USGS Publications Warehouse

    Garner, Bradley D.; Bills, Donald J.

    2012-01-01

    Synoptic base-flow surveys were conducted on streams in the Verde Valley, central Arizona, in June 2007 and February 2011 by the U.S. Geological Survey (USGS), in cooperation with the Verde River Basin Partnership, the Town of Clarkdale, and Yavapai County. These surveys, also known as seepage runs, measured streamflow under base-flow conditions at many locations over a short period of time. Surveys were conducted on a segment of the Verde River that flows through the Verde Valley, between USGS streamflow-gaging stations 09504000 and 09506000, a distance of 51 river miles. Data from the surveys were used to investigate the dominant controls on Verde River base flow, spatial variability in gaining and losing reaches, and the effects that human alterations have on base flow in the surface-water system. The most prominent human alterations in the Verde Valley are dozens of surface-water diversions from streams, including gravity-fed ditch diversions along the Verde River.Base flow that entered the Verde River from the tributary streams of Oak Creek, Beaver Creek, and West Clear Creek was found to be a major source of base flow in the Verde River. Groundwater discharge directly into the Verde River near these three confluences also was an important contributor of base flow to the Verde River, particularly near the confluence with Beaver Creek. An examination of individual reaches of the Verde River in the Verde Valley found three reaches (largely unaffected by ditch diversions) exhibiting a similar pattern: a small net groundwater discharge in February 2011 (12 cubic feet per second or less) and a small net streamflow loss in June 2007 (11 cubic feet per second or less). Two reaches heavily affected by ditch diversions were difficult to interpret because of the large number of confounding human factors. Possible lower and upper bounds of net groundwater flux were calculated for all reaches, including those heavily affected by ditches.

  20. Central and South West Services (CSWS) transmission system studies: (Rio Grande Valley FACTS studies). Final report

    SciTech Connect

    Arabi, S.; Hamadanizadeh, H.

    1998-12-01

    Stability limitations impose constraints on power imports into the Rio Grande Valley, the southern region of Central Power and Light`s (CPL) system. CPL`s parent company, Central and South West Services, sought to identify viable plans for eliminating these constraints to enable power transfers via two 345-kV transmission lines. This project conducted assessment studies of the CPL system, using applications from EPRI`s Power System Analysis Package, and identified two scenarios as the most likely remedial measures required. These consisted of the addition of generating units and the use of series compensation of the two transmission lines, in conjunction with shunt compensation. While Flexible AC Transmission System (FACTS) devices were not indicated in this study phase, the researchers indicated a Thyristor Controlled Series Compensation device could be considered to address a potential subsynchronous resonance issue.

  1. Predicting Arsenic in Drinking Water Wells of the Central Valley, California.

    PubMed

    Ayotte, Joseph D; Nolan, Bernard T; Gronberg, Jo Ann

    2016-07-19

    Probabilities of arsenic in groundwater at depths used for domestic and public supply in the Central Valley of California are predicted using weak-learner ensemble models (boosted regression trees, BRT) and more traditional linear models (logistic regression, LR). Both methods captured major processes that affect arsenic concentrations, such as the chemical evolution of groundwater, redox differences, and the influence of aquifer geochemistry. Inferred flow-path length was the most important variable but near-surface-aquifer geochemical data also were significant. A unique feature of this study was that previously predicted nitrate concentrations in three dimensions were themselves predictive of arsenic and indicated an important redox effect at >10 μg/L, indicating low arsenic where nitrate was high. Additionally, a variable representing three-dimensional aquifer texture from the Central Valley Hydrologic Model was an important predictor, indicating high arsenic associated with fine-grained aquifer sediment. BRT outperformed LR at the 5 μg/L threshold in all five predictive performance measures and at 10 μg/L in four out of five measures. BRT yielded higher prediction sensitivity (39%) than LR (18%) at the 10 μg/L threshold-a useful outcome because a major objective of the modeling was to improve our ability to predict high arsenic areas.

  2. Conodont biostratigraphy of the Ordovician-Silurian boundary in the Central Appalachian Valley and Ridge Province

    SciTech Connect

    Philips, P.L. Jr.; Hall, J.C. . Dept. of Earth Sciences)

    1993-03-01

    Conodont biostratigraphy of the Ordovician-Silurian boundary in the Central Appalachian Valley and Ridge Province is based primarily on lithologic criteria. Although the boundary is precisely defined lithologically, virtually nothing is known about the biostratigraphic relationships in this interval due to a historic lack of detailed studies in this region. The present study is based on nearly 50 samples from 7 sections in Tennessee and Virginia, aimed at establishing a conodont-based biostratigraphic framework useful for local and regional correlation of lithostratigraphic units and boundaries. The data at hand show uppermost Ordovician rocks in this region have conodont faunas which are characterized by species of Oulodus, Aphelognathus, Phragmodus, and Plectodina. These faunas represent associations which locally correspond to the Oulodus velicuspis to Aphelognathus divergens Zones. Lowermost Silurian rocks contain faunas dominated by species of Ozarkodina, Distomodus, Pranognathus, and Walliserodus that correspond to the faunas of the Distomodus kentuckyensis Zone. Conodont ages indicate that the uppermost Ordovician rocks in the Central Appalachians range in age from upper Edenian to upper Richmondian and lowermost Silurian rocks range in age from upper Rhuddanian to lower Telychian in age. No conodont faunas which characterize the uppermost Richmondian, Gamachian, or lowermost Rhuddanian have yet been identified. The results of this study are in agreement with those of out previous study of the Southern Appalachian Valley and Ridge Province.

  3. Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations

    USGS Publications Warehouse

    Brown, Larry R.; Bauer, Marissa L.

    2010-01-01

    Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologic infrastructure and management affect streamflow characteristics of rivers in the Central Valley, California and discuss those characteristics in the context of habitat requirements of native and alien fishes. We evaluated the effects of water management by comparing observed discharges with estimated discharges assuming no water management ("full natural runoff"). Rivers in the Sacramento River drainage were characterized by reduced winter–spring discharges and augmented discharges in other months. Rivers in the San Joaquin River drainage were characterized by reduced discharges in all months but particularly in winter and spring. Two largely unaltered streams had hydrographs similar to those based on full natural runoff of the regulated rivers. The reduced discharges in the San Joaquin River drainage streams are favourable for spawning of many alien species, which is consistent with observed patterns of fish distribution and abundance in the Central Valley. However, other factors, such as water temperature, are also important to the relative success of native and alien resident fishes. As water management changes in response to climate change and societal demands, interdisciplinary programs of research and monitoring will be essential for anticipating effects on fishes and to avoid unanticipated ecological outcomes.

  4. Predicting arsenic in drinking water wells of the Central Valley, California

    USGS Publications Warehouse

    Ayotte, Joseph; Nolan, Bernard T.; Gronberg, JoAnn M.

    2016-01-01

    Probabilities of arsenic in groundwater at depths used for domestic and public supply in the Central Valley of California are predicted using weak-learner ensemble models (boosted regression trees, BRT) and more traditional linear models (logistic regression, LR). Both methods captured major processes that affect arsenic concentrations, such as the chemical evolution of groundwater, redox differences, and the influence of aquifer geochemistry. Inferred flow-path length was the most important variable but near-surface-aquifer geochemical data also were significant. A unique feature of this study was that previously predicted nitrate concentrations in three dimensions were themselves predictive of arsenic and indicated an important redox effect at >10 μg/L, indicating low arsenic where nitrate was high. Additionally, a variable representing three-dimensional aquifer texture from the Central Valley Hydrologic Model was an important predictor, indicating high arsenic associated with fine-grained aquifer sediment. BRT outperformed LR at the 5 μg/L threshold in all five predictive performance measures and at 10 μg/L in four out of five measures. BRT yielded higher prediction sensitivity (39%) than LR (18%) at the 10 μg/L threshold–a useful outcome because a major objective of the modeling was to improve our ability to predict high arsenic areas.

  5. Tracking sediment through the Holocene: Determining anthropogenic contributions to a sediment-rich agricultural system, north-central USA

    NASA Astrophysics Data System (ADS)

    Gran, Karen; Belmont, Patrick; Finnegan, Noah

    2013-04-01

    Management and restoration of sediment-impaired streams requires quantification of sediment sources and pathways of transport. Addressing the role of humans in altering the magnitude and sources of sediment supplied to a catchment is notoriously challenging. Here, we explore how humans have amplified erosion in geomorphically-sensitive portions of the predominantly-agricultural Minnesota River basin in north-central USA. In the Minnesota River basin, the primary sources of sediment are classified generally as upland agricultural field vs. near-channel sources, with near-channel sources including stream banks, bluffs, and ravines. Using aerial lidar data, repeat terrestrial lidar scans of bluffs, ravine monitoring, historic air photo analyses, and sediment fingerprinting, we have developed a sediment budget to determine the relative importance of each source in a tributary to the Minnesota River, the Le Sueur River. We then investigate how these sources have changed through time, from changes evident over the past few decades to changes associated with valley evolution over the past 13,400 years. The Minnesota River valley was carved ~13,400 years ago through catastrophic drainage of glacial Lake Agassiz. As the Minnesota River valley incised, knickpoints have migrated upstream into tributaries, carving out deep valleys where the most actively eroding near-channel sediment sources occur. The modern sediment budget, closed for the time period 2000 to 2010, shows that the majority of the fine sediment load in the Le Sueur River comes from bluffs and other near-channel sources in the deeply-incised knick zone. Numerical modeling of valley evolution constrained by mapped and dated strath terraces cut into the glacial till presents an opportunity to compare the modern sediment budget to that of the river prior to anthropogenic modification. This comparison reveals a natural background or "pre-agriculture" rate of erosion from near-channel sources to be 3-5 times lower

  6. Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California

    USGS Publications Warehouse

    Pigati, J.S.; Miller, D.M.; Bright, J.E.; Mahan, S.A.; Nekola, J.C.; Paces, J.B.

    2011-01-01

    groundwater supported persistent and long-lived desert wetlands in many broad valleys and basins in the American Southwest. When active, these systems provided important food and water sources for local fauna, supported hydrophilic and phreatophytic vegetation, and acted as catchments for eolian and alluvial sediments. Desert wetlands are represented in the geologic record by groundwater discharge deposits, which are also called spring or wetland deposits. Groundwater discharge deposits contain information on the timing and magnitude of past changes in water-table levels and, thus, are a source of paleohydrologic and paleoclimatic information. Here, we present the results of an investigation of extensive groundwater discharge deposits in the central Mojave Desert at Valley Wells, California. We used geologic mapping and stratigraphic relations to identify two distinct wetland sequences at Valley Wells, which we dated using radiocarbon, luminescence, and uranium-series techniques. We also analyzed the sediments and microfauna (ostracodes and gastropods) to reconstruct the specific environments in which they formed. Our results suggest that the earliest episode of high water-table conditions at Valley Wells began ca. 60 ka (thousands of calendar yr B.P.), and culminated in peak discharge between ca. 40 and 35 ka. During this time, cold (4-12 ??C) emergent groundwater supported extensive wetlands that likely were composed of a wet, sedge-rush-tussock meadow mixed with mesic riparian forest. After ca. 35 ka, the water table dropped below the ground surface but was still shallow enough to support dense stands of phreatophytes through the Last Glacial Maximum (LGM). The water table dropped further after the LGM, and xeric conditions prevailed until modest wetlands returned briefly during the Younger Dryas cold event (13.0-11.6 ka). We did not observe any evidence of wet conditions during the Holocene at Valley Wells. The timing of these fluctuations is consistent with

  7. Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California

    USGS Publications Warehouse

    Pigati, Jeffrey S.; Miller, David M.; Bright, Jordon E.; Mahan, Shannon; Nekola, Jeffrey C.; Paces, James B.

    2011-01-01

    During the late Pleistocene, emergent groundwater supported persistent and long-lived desert wetlands in many broad valleys and basins in the American Southwest. When active, these systems provided important food and water sources for local fauna, supported hydrophilic and phreatophytic vegetation, and acted as catchments for eolian and alluvial sediments. Desert wetlands are represented in the geologic record by groundwater discharge deposits, which are also called spring or wetland deposits. Groundwater discharge deposits contain information on the timing and magnitude of past changes in water-table levels and, thus, are a source of paleohydrologic and paleoclimatic information. Here, we present the results of an investigation of extensive groundwater discharge deposits in the central Mojave Desert at Valley Wells, California. We used geologic mapping and stratigraphic relations to identify two distinct wetland sequences at Valley Wells, which we dated using radiocarbon, luminescence, and uranium-series techniques. We also analyzed the sediments and microfauna (ostracodes and gastropods) to reconstruct the specific environments in which they formed. Our results suggest that the earliest episode of high water-table conditions at Valley Wells began ca. 60 ka (thousands of calendar yr B.P.), and culminated in peak discharge between ca. 40 and 35 ka. During this time, cold (4–12 °C) emergent groundwater supported extensive wetlands that likely were composed of a wet, sedge-rush-tussock meadow mixed with mesic riparian forest. After ca. 35 ka, the water table dropped below the ground surface but was still shallow enough to support dense stands of phreatophytes through the Last Glacial Maximum (LGM). The water table dropped further after the LGM, and xeric conditions prevailed until modest wetlands returned briefly during the Younger Dryas cold event (13.0–11.6 ka). We did not observe any evidence of wet conditions during the Holocene at Valley Wells. The timing

  8. [Ethnic conflicts and environmental degradation in Central Asia. The Ferghana valley and northern Kazakhstan].

    PubMed

    De Cordier, B

    1996-01-01

    This work seeks to demonstrate that the combination of ecological degradation, demographic pressure, and ethnic heterogeneity in Central Asia constitute a serious threat to the future stability of the region. The predominantly rural Ferghana Valley and Northern Kazakhstan suffer from shortages of water and land and from unemployment that leads to extensive out-migration to cities suffering from decline in their Soviet-era industries. The problem in the Ferghana Valley began with Tsarist conquest of the valley in 1876 and the subsequent imposition of cotton cultivation, which was greatly expanded by the Soviet Union. The Ferghana Valley, despite being a natural unit, was divided between Uzbekistan, Tajikistan, and Kyrgyzstan in the 1920s and 1930s, and remains divided between the independent states. The current population of 11 million is ethnically diverse, with Uzbeks in the majority and increasing most rapidly. Immigration from the Caucasus since 1950 added to the tension. Future peace will depend on such factors as whether the neo-Communist political regime chooses to incite ethnic hostilities, the manner in which land is redistributed, and the outcome of struggles for control of the flourishing narcotics trade. The northern Kazakhstan region was designated a pioneer wheat-growing region by Soviet planners in 1954. Russian and Ukrainian migrants established between 1954 and 1956 are today the predominant population sector, but feel their privileged position threatened by nationalist policies making Kazakh the official language and giving preference in employment to Kazakhs. Resettlement of Kazakhs from Mongolia, China, and Afghanistan in the region and the high Kazakh birth rate increase tensions. Grain production initially grew rapidly, but the mediocre soil and erosion-inducing constant dry winds have caused production to stagnate or decline. Regional disputes within Kazakhstan complicate the situation. Northern Kazakhstan, with its industrial development, is

  9. Viscous flow lobes in central Taylor Valley, Antarctica: Origin as remnant buried glacial ice

    NASA Astrophysics Data System (ADS)

    Swanger, Kate M.; Marchant, David R.; Kowalewski, Douglas E.; Head, James W., III

    2010-08-01

    Viscous flow lobes are common throughout the McMurdo Dry Valleys (MDV) of Antarctica. These features have been described as rock glaciers, gelifluction lobes, solifluction lobes, talus mobilized by pore ice and/or segregation ice, and debris-covered glaciers. We investigate the origin, modification, and flow of a 2-km-long lobe (East Stocking Lobe or ESL) along the north wall of central Taylor Valley using field mapping techniques, shallow seismic surveys, time-dependent displacement surveys, and isotopic analyses of buried-ice samples. On the basis of these integrated analyses, we show that the ESL is cored with remnant glacier ice, most probably derived from an advance of nearby Stocking Glacier ˜ 130 kyr BP. Seismic data, coupled with results from ice-flow modeling assuming plastic flow of clean ice, suggest that the buried core of glacier ice is ˜ 14- to 30-m thick. Near its terminus, the ESL flows at a rate of ˜ 2.4 to 6.7 mm a - 1 . The loose drift that caps the buried ice (typically < 1 m thick) is composed of moderately stratified sand- and gravel-sized clasts; it is dry (1-3% soil gravimetric water content; GWC), except near ephemeral stream channels and the margins of melting snow banks (6-25% GWC). Stable isotopic analyses of samples from the upper 30 cm of the ice lie on a slope of ˜ 5.8 (when plotted on a δD vs. δ18O graph), well below the local meteoric water line of 7.75, suggesting modification by freeze/thaw processes and evaporation/sublimation. Measured air and soil temperatures show that intermittent melting is most likely possible during summer months where buried ice is ≤ 35 cm below the ground surface. Morphological comparisons with ice-cored deposits in upland regions of the Dry Valleys, e.g., Mullins and Beacon Valleys (30 km inland and ˜ 500 m higher in elevation), and near the coast (40 km distant and ˜ 500 m lower) reveal marked contrasts in the style of near-surface ice degradation and cryoturbation. From these morphological

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

    USGS Publications Warehouse

    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

  11. An Airborne Investigation of Boundary Layer Dynamics, Entrainment, and Ozone Photochemical Production During DISCOVER-AQ in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Conley, S. A.; Post, A.; Faloona, I. C.

    2014-12-01

    During the California deployment of NASA's DISCOVER-AQ project of January/February 2013, our team flew a Mooney TLS research aircraft instrumented with an in-house wind measurement system, a UV absorption ozone instrument, temperature probe, and a Picarro methane, carbon dioxide, and water vapor analyzer. Flights were focused on the lowest 1000 m across the Central Valley axis just north of Fresno in order to characterize the wintertime atmospheric boundary layer (ABL). For seven flights we report the observed ABL growth rates, and compare these with a simple mixed layer model driven by surface heat flux estimates from the North American Regional Reanalysis data set. By enforcing a mixed layer budget closure of the observed water vapor trend and the differential across the ABL top, we derive midday entrainment velocities for the region that average 1.2 (± 0.4) cm s-1. A similar budgeting method is used for ozone to estimate wintertime photochemical production rates that ranged from 0.5 to 7.0 ppb h-1, and exhibited a strong correlation with ambient temperature (see Figure) and total ozone abundance. Finally, the gross emissions of methane for this heavily agricultural region are estimated and compared to existing inventories. These results can provide important constraints on ABL growth and entrainment to aid surface studies of aerosol composition and other trace gases that are being conducted for DISCOVER-AQ.

  12. Glacial stages and post-glacial environmental evolution in the Upper Garonne valley, Central Pyrenees.

    PubMed

    Fernandes, M; Oliva, M; Palma, P; Ruiz-Fernández, J; Lopes, L

    2017-04-15

    The maximum glacial extent in the Central Pyrenees during the Last Glaciation is known to have occurred before the global Last Glacial Maximum, but the succession of cold events afterwards and their impact on the landscape are still relatively unknown. This study focuses on the environmental evolution in the upper valley of the Garonne River since the Last Glaciation. Geomorphological mapping allows analysis of the spatial distribution of inherited and current processes and landforms in the study area. The distribution of glacial records (moraines, till, erratic boulders, glacial thresholds) suggests the existence of four glacial stages, from the maximum expansion to the end of the glaciation. GIS modeling allows quantification of the Equilibrium Line Altitude, extent, thickness and volume of ice in each glacial stage. During the first stage, the Garonne glacier reached 460m in the Loures-Barousse-Barbazan basin, where it formed a piedmont glacier 88km from the head and extended over 960km(2). At a second stage of glacier stabilization during the deglaciation process, the valley glaciers were 12-23km from the head until elevations of 1000-1850m, covering an area of 157km(2). Glaciers during stage three remained isolated in the upper parts of the valley, at heights of 2050-2200m and 2.6-4.5km from the head, with a glacial surface of 16km(2). In stage four, cirque glaciers were formed between 2260m and 2590m, with a length of 0.4-2km and a glacial area of 5.7km(2). Also, the wide range of periglacial, slope, nival and alluvial landforms existing in the formerly glaciated environments allows reconstruction of the post-glacial environmental dynamics in the upper Garonne basin. Today, the highest lands are organized following three elevation belts: subnival (1500-1900m), nival (1900-2300m) and periglacial/cryonival (2300-2800m).

  13. Remediation of Mudboil Discharges in the Tully Valley of Central New York

    USGS Publications Warehouse

    Kappel, William M.

    2009-01-01

    Mudboils have been documented in the Tully Valley in Onondaga County, in central New York State, since the late 1890s and have continuously discharged sediment-laden (turbid) water into nearby Onondaga Creek since the 1950s. The discharge of sediment causes gradual land-surface subsidence that, in the past, necessitated rerouting a major petroleum pipeline and a buried telephone cable, and caused two road bridges to collapse. The turbid water discharged from mudboils can be either fresh or brackish (salty). Mudboil activity was first reported in the Syracuse, NY, Post Standard in a short article dated October 19, 1899: 'Tully Valley - A Miniature Volcano Few people are aware of the existence of a volcano in this town. It is a small one, to be sure, but very interesting. In the 20-rod gorge where the crossroad leads by the Tully Valley grist mill the hard highway bed has been rising foot after foot till the apex of a cone which has been booming has broken open and quicksand and water flow down the miniature mountain sides. It is an ever increasing cone obliterating wagon tracks as soon as crossed. The nearby bluff is slowly sinking. Probably the highway must sometime be changed on account of the sand and water volcano, unless it ceases its eruption.' This newspaper article accurately describes mudboil activity and presages the collapse of the Otisco Road bridge, 92 years later in 1991. The article indicates that land subsidence occurred nearby, but gives no indication that Onondaga Creek was turbid; this was either an oversight by the reporter or was not a concern at that time.

  14. Evaluating spatial and temporal variations of rainfall erosivity, case of Central Rift Valley of Ethiopia

    NASA Astrophysics Data System (ADS)

    Meshesha, Derege Tsegaye; Tsunekawa, Atsushi; Tsubo, Mitsuru; Haregeweyn, Nigussie; Adgo, Enyew

    2015-02-01

    Land degradation in many Ethiopian highlands occurs mainly due to high rainfall erosivity and poor soil conservation practices. Rainfall erosivity is an indicator of the precipitation energy and ability to cause soil erosion. In Central Rift Valley (CRV) of Ethiopia, where the climate is characterized as arid and semiarid, rainfall is the main driver of soil erosion that in turn causes a serious expansion in land degradation. In order to evaluate the spatial and temporal variability of rainfall erosivity and its impact on soil erosion, long-term rainfall data (1980-2010) was used, and the monthly Fournier index (FI) and the annual modified Fournier index (MFI) were applied. Student's t test analysis was performed particularly to examine statistical significances of differences in average monthly and annual erosivity values. The result indicated that, in a similar spatial pattern with elevation and rainfall amount, average annual erosivity is also found being higher in western highlands of the valley and gradually decreased towards the east. The long-term average annual erosivity (MFI) showed a general decreasing trend in recent 10 years (2000-2010) as compared to previous 20 years (1980-1999). In most of the stations, average erosivity of main rainy months (May, June, July, and August) showed a decreasing trend, whereby some of them (about 33.3 %) are statically significant at 90 and 95 % confidence intervals but with high variation in spatial pattern of changes. The overall result of the study showed that rainfall aggression (erosivity) in the region has a general decreasing trend in the recent decade as compared to previous decades, especially in the western highlands of the valley. Hence, it implies that anthropogenic factors such as land use change being coupled with topography (steep slope) have largely contributed to increased soil erosion rate in the region.

  15. Sources of methane and nitrous oxide in California's Central Valley estimated through direct airborne flux and positive matrix factorization source apportionment of groundbased and regional tall tower measurements

    NASA Astrophysics Data System (ADS)

    Guha, Abhinav

    Methane (CH4) and nitrous oxide (N2O) are two major greenhouse gases that contribute significantly to the increase in anthropogenic radiative-forcing causing perturbations to the earth's climate system. In a watershed moment in the state's history of environmental leadership and commitment, California, in 2006, opted for sharp reductions in their greenhouse gas (GHG) emissions and adopted a long-term approach to address climate change that includes regulation of emissions from individual emitters and source categories. There are large CH4 and N2O emissions sources in the state, predominantly in the agricultural and waste management sector. While these two gases account for < 10% of total annual greenhouse gas emissions of the state, large uncertainties exist in their `bottom-up' accounting in the state GHG inventory. Additionally, an increasing number of `top-down' studies based on ambient observations point towards underestimation of their emissions in the inventory. Three intensive field observation campaigns that were spatially and temporally diverse took place between 2010 and 2013 in the Central Valley of California where the largest known sources of CH4 and N2O (e.g. agricultural systems and dairies) and potentially significant CH4 sources (e.g. oil and gas extraction) are located. The CalNex (California Nexus - Research at the Nexus of Air Quality and Climate Change) field campaign during summer 2010 (May 15 - June 30) took place in the urban core of Bakersfield in the southern San Joaquin Valley, a city whose economy is built around agriculture and the oil and gas industry. During summer of 2011, airborne measurements were performed over a large spatial domain, all across and around the Central Valley as part of the CABERNET (California Airborne BVOC Emission Research in Natural Ecosystem Transects) study. Next, a one-year continuous field campaign (WGC 2012-13, June 2012 - August 2013) was conducted at the Walnut Grove tall tower near the Sacramento

  16. Methods, quality assurance, and data for assessing atmospheric deposition of pesticides in the Central Valley of California

    USGS Publications Warehouse

    Zamora, Celia; Majewski, Michael S.; Foreman, William T.

    2013-01-01

    The U.S. Geological Survey monitored atmospheric deposition of pesticides in the Central Valley of California during two studies in 2001 and 2002–04. The 2001 study sampled wet deposition (rain) and storm-drain runoff in the Modesto, California, area during the orchard dormant-spray season to examine the contribution of pesticide concentrations to storm runoff from rainfall. In the 2002–04 study, the number and extent of collection sites in the Central Valley were increased to determine the areal distribution of organophosphate insecticides and other pesticides, and also five more sample types were collected. These were dry deposition, bulk deposition, and three sample types collected from a soil box: aqueous phase in runoff, suspended sediment in runoff, and surficial-soil samples. This report provides concentration data and describes methods and quality assurance of sample collection and laboratory analysis for pesticide compounds in all samples collected from 16 sites. Each sample was analyzed for 41 currently used pesticides and 23 pesticide degradates, including oxygen analogs (oxons) of 9 organophosphate insecticides. Analytical results are presented by sample type and study period. The median concentrations of both chloryprifos and diazinon sampled at four urban (0.067 micrograms per liter [μg/L] and 0.515 μg/L, respectively) and four agricultural sites (0.079 μg/L and 0.583 μg/L, respectively) during a January 2001 storm event in and around Modesto, Calif., were nearly identical, indicating that the overall atmospheric burden in the region appeared to be fairly similar during the sampling event. Comparisons of median concentrations in the rainfall to those in the McHenry storm-drain runoff showed that, for some compounds, rainfall contributed a substantial percentage of the concentration in the runoff; for other compounds, the concentrations in rainfall were much greater than in the runoff. For example, diazinon concentrations in rainfall were about

  17. Large quaternary landslides in the central appalachian valley and ridge province near Petersburg, West Virginia

    USGS Publications Warehouse

    Scott, Southworth C.

    1988-01-01

    Geological mapping and photointerpretation of side-looking airborne radar images and color-infrared aerial photographs reveal two large Quaternary landslides in the Valley and Ridge province of the central Appalachians near Petersburg, W. Va. The Elkhorn Mountain rock avalanche occurs on the thrust-faulted northwestern flank of the Elkhorn Mountain anticlinorium. A minimum of 7 ?? 106 m3 of quartzite colluvium was transported more than 3 km from a 91 m high escarpment of Silurian Tuscarora Quartzite. The extensively vegetated deposit may owe, in part, its transport and weathering to periglacial conditions during the Pleistocene. In contrast, the Gap Mountain rock block slide is a single allochthonous block that is 1.2 km long, 0.6 km wide, and at least 60 m thick. The 43 ?? 106 m3 block is composed of limestone of the Helderberg Group and the Oriskany Sanstone of Early Devonian age. Planar detachment probably occurred along a dissolution bedding plane near the Shriver Chert and the Oriskany Sandstone contact. Failure probably was initiated by downcutting of the South Branch Potomac River during the Pleistocene. Landslides of this magnitude suggest accelerated erosion during periglacial climates in the Pleistocene. The recognition of these large slope failures may provide evidence of paleoclimatic conditions and, thereby, increase our understanding of the geomorphologic development of the Valley and Ridge province. ?? 1988.

  18. Ground-water data in the Corvallis-Albany area, central Willamette Valley, Oregon

    USGS Publications Warehouse

    Frank, F.J.; Johnson, N.A.

    1972-01-01

    THE CORVALLIS-ALBANY AREA IS PART OF THE ALLUVIAL PLAIN THAT LIES BETWEEN THE CASCADE AND COAST RANGES IN THE CENTRAL WILLAMETTE VALLEY IN NORTHWESTERN OREGON. THE ALLUVIAL DEPOSITS (SAND AND GRAVEL) OF THE VALLEY PLAIN CONTAIN THE MOST PRODUCTIVE AQUIFERS IN THE AREA AND ARE CONSIDERED TO BE THE ONLY UNITS FEASIBLE FOR LARGE-SCALE DEVELOPMENT OF GROUNDWATER SUPPLIES. DURING 1971 THE SEASONAL DECLINE OF WATER LEVELS FROM WINTER TO LATE SUMMER AVERAGED ABOUT 10 FEET FOR THE ALLUVIAL DEPOSITS. THE SEASONAL CHANGE OF STORAGE WAS ESTIMATED TO BE ABOUT 130,000 ACRE-FEET. OF THIS VOLUME, ABOUT 14,000 ACRE-FEET WAS PUMPED FROM WELLS; THE REST WAS DISCHARGED THROUGH SEEPS AND SPRINGS BY EVAPOTRANSPIRATION. THE DIFFERENCE BETWEEN PUMPAGE AND NATURAL DISCHARGE INDICATES THAT A GREAT QUANTITY OF ADDITIONAL WATER IS AVAILABLE FOR DEVELOPMENT. THE STORAGE CAPACITY OF THE ALLUVIAL AQUIFERS IS ESTIMATED TO BE ABOUT 750,000 ACRE-FEET BETWEEN DEPTHS OF 10 AND 100 FEET. WATER FROM THE ALLUVIAL DEPOSITS IS CHEMICALLY SUITABLE FOR ALL USES, AS IS MOST OF THE WATER FROM PERCHED-WATER BODIES IN THE OLDER SEDIMENTARY AND VOLCANIC ROCKS.

  19. A plan to study the aquifer system of the Central Valley of California

    USGS Publications Warehouse

    Bertoldi, Gilbert L.

    1979-01-01

    Unconsolidated Quaternary alluvial deposits comprise a large complex aquifer system in the Central Valley of California. Millions of acre-feet of water is pumped from the system annually to support a large and expanding agribusiness industry. Since the 1950's, water levels have been steadily declining in many areas of the valley and concern has been expressed about the ability of the entire ground-water system to support agribusiness at current levels, not to mention its ability to function at projected expansion levels. At current levels of ground-water use, an estimated 1.5 to 2 million acre-feet is withdrawn from storage each year; that is, 1.5 to 2 million acre-feet of water is pumped annually in excess of annual replenishment. The U.S. Geological Survey has initiated a 4-year study to develop geologic, hydrologic, and hydraulic information and to establish a valleywide ground-water data base that will be used to build computer models of the ground-water flow system. Subsequently, these models may be used to evaluate the system response to various ground-water management alternatives. This report describes current problems, objectives of the study, and outlines the general work to be accomplished in the study area. A bibliography of about 600 references is included. (Kosco-USGS)

  20. Buried paleoindian-age landscapes in stream valleys of the central plains, USA

    USGS Publications Warehouse

    Mandel, R.D.

    2008-01-01

    A systematic study of late-Quaternary landscape evolution in the Central Plains documented widespread, deeply buried paleosols that represent Paleoindian-age landscapes in terrace fills of large streams (> 5th order), in alluvial fans, and in draws in areas of western Kansas with a thick loess mantle. Alluvial stratigraphic sections were investigated along a steep bio-climatic gradient extending from the moist-subhumid forest-prairie border of the east-central Plains to the dry-subhumid and semi-arid shortgrass prairie of the west-central Plains. Radiocarbon ages indicate that most large streams were characterized by slow aggradation accompanied by cumulic soil development from ca. 11,500 to 10,000??14C yr B.P. In the valleys of some large streams, such as the Ninnescah and Saline rivers, these processes continued into the early Holocene. The soil-stratigraphic record in the draws of western Kansas indicates slow aggradation punctuated by episodes of landscape stability and pedogenesis beginning as early as ca. 13,300??14C yr B.P. and spanning the Pleistocene-Holocene boundary. The development record of alluvial fans in western Kansas is similar to the record in the draws; slow aggradation was punctuated by multiple episodes of soil development between ca. 13,000 and 9000??14C yr B.P. In eastern Kansas and Nebraska, development of alluvial fans was common during the early and middle Holocene, but evidence shows fan development as early as ca. 11,300??14C yr B.P. Buried soils dating between ca. 12,600 and 9000??14C yr B.P. were documented in fans throughout the region. In stream valleys across the Central Plains, rapid alluviation after ca. 9000??14C yr B.P. resulted in deeply buried soils that may harbor Paleoindian cultural deposits. Hence, the paucity of recorded stratified Paleoindian sites in the Central Plains is probably related to poor visibility (i.e., deep burial in alluvial deposits) instead of limited human occupation in the region during the terminal

  1. Ground water in the Corvallis-Albany area, central Willamette Valley, Oregon

    USGS Publications Warehouse

    Frank, Frank J.

    1974-01-01

    The Corvallis-Albany area is part of the alluvial plain that lies between the Cascade and Coast Ranges in the central Willamette Valley in northwestern Oregon. As used in this report, the Corvallis-Albany area consists of approximately 210 square miles and includes a part of the lower foothills of the Coast and Cascade Ranges. Volcanic and marine sedimentary units exposed in the foothills range in age from Eocene to Oligocene or Miocene. The volcanic rocks are primarily pillow lavas and basalt flows, which yield only small quantities of water generally adequate for domestic and stock use. Marine-deposited sandstone, siltstone, and shale of the older sedimentary units are fine grained, poorly permeable, and generally yield small volumes of water to wells. In the valley plain the older units are overlain by Pleistocene and Holocene alluvial deposits. The alluvial deposits (sand and gravel) of the valley plain contain the most productive aquifers in the area and are considered to be the only units feasible for large-scale development of ground-water supplies. Aquifers in the area are recharged principally by direct infiltration of precipitation. Most of the precipitation (about 38 in. per yr avg) occurs during late autumn and winter. Ground water is discharged naturally from the area by seepage and spring flow to streams, by evapotranspiration, by underflow, and artificially through wells. During 1971 the seasonal decline of water levels from winter to late summer averaged about 10 feet for the alluvial deposits. The seasonal change of storage in that year was estimated to be about 130,000 acre-feet. Of this volume, about 14,000 acre-feet was pumped from wells; the rest (about 116,000 acre-feet) was discharged through seeps and springs by evapotranspiration. The difference between pumpage and natural discharge indicates that a great quantity of additional water is available for development. The storage capacity of the alluvial aquifers in the area is estimated to be

  2. Depth to water, 1991, in the Rathdrum Prairie, Idaho; Spokane River valley, Washington; Moscow-Lewiston-Grangeville area, Idaho; and selected intermontane valleys, east-central Idaho

    USGS Publications Warehouse

    Berenbrock, Charles E.; Bassick, M.D.; Rogers, T.L.; Garcia, S.P.

    1995-01-01

    This map report illustrates digitally generated depth-to-water zones for the Rathdrum Prairie in Idaho; part of the Spokane River Valley in eastern Washington; and the intermontane valleys of the upper Big Wood, Big Lost, Pahsimeroi, Little Lost, and Lemhi Rivers and Birch Creek in Idaho. Depth to water is 400 to 500 feet below land surface in the northern part of Rathdrum Prairie, 100 to 200 feet below land surface at the Idaho-Washington State line, and 0 to 250 feet below land surface in the Spokane area. Depth to water in the intermontane valleys in east-central Idaho is least (usually less than 50 feet) near streams and increases toward valley margins where mountain-front alluvial fans have formed. Depths to water shown in the Moscow-Lewiston-Grangeville area in Idaho are limited to point data at individual wells because most of the water levels measured were not representative of levels in the uppermost aquifer but of levels in deeper aquifers.

  3. Community health centers: a promising venue for supplemental nutrition assistance program education in the Central Valley.

    PubMed

    MkNelly, Barbara; Nishio, Stephanie; Peshek, Cynthia; Oppen, Michelle

    2011-01-01

    Health care providers could help achieve the necessary shift to healthful eating and active living; however, lack of coverage or reimbursement, lack of time, and limited information about appropriate interventions are some of the documented barriers. This report highlights the potential for Supplemental Nutrition Assistance Program Education (SNAP-Ed) implementation in the relatively nontraditional setting of Federally Qualified Health Centers based on the experience of the Central Valley Health Network's Nutrition Education Demonstration Project. The report provides a brief overview of the primary prevention role(s) suggested for health care providers, relevant SNAP-Ed policies, how SNAP-Ed has been implemented in Federally Qualified Health Center settings, and recommendations for similar efforts.

  4. Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

    NASA Technical Reports Server (NTRS)

    Lewis, Jasper R., Jr.; DeYoung, Russell J.; Chu, D. Allen

    2010-01-01

    Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2008. While the PM2.5 concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM2.5 in the winter can exceed summer PM2.5 by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Measurements of the boundary layer height from lidar instruments are necessary to incorporate satellite measurements with air quality measurements.

  5. The Dynamics of Social Indicator Research for California’s Central Valley in Transition

    PubMed Central

    Hernandez, Marcia D.; Sylvester, Dari E.; Weffer, Simón E.

    2010-01-01

    How can social indicator research improve understanding of community health as well as inform stakeholders about the assets disadvantaged communities have for coping with disparities? This paper describes the development and evolution of the Partnership for Assessment of Communities (PAC) and its best practices for social indicator research. The PAC will be of interest to researchers across multiple disciplines for a number of reasons. First, PAC is a working model of best practices for multidisciplinary scholarly inquiry. Second, it has developed an integrated model of quantitative and qualitative methodology to define and measure community health as compared to traditional quality-of-life indicators. Third, it serves as an example of “action research,” in that the findings have the potential to make an impact on community stakeholders and policy outcomes in the greater Central San Joaquin Valley of California, a region characterized by deep social and economic disparities. PMID:21212814

  6. Agriculture, irrigation, and drainage on the west side of the San Joaquin Valley, California: Unified perspective on hydrogeology, geochemistry and management

    SciTech Connect

    Narasimhan, T.N.; Quinn, N.W.T.

    1996-03-01

    The purpose of this report is to provide a broad understanding of water-related issues of agriculture and drainage on the west side of the San Joaquin Valley. To this end, an attempt is made to review available literature on land and water resources of the San Joaquin Valley and to generate a process-oriented framework within which the various physical-, chemical-, biological- and economic components of the system and their interactions are placed in mutual perspective.

  7. Water Quality and Supply Issues of Irrigated Agricultural Regions - Lessons from the San Joaquin Valley of California

    NASA Astrophysics Data System (ADS)

    Suen, C. J.; Wang, D.

    2014-12-01

    The San Joaquin Valley of California covers 4 million hectares of farmland and produces $25 billion of agricultural products annually, but its average annual rainfall ranges from only 130 mm in the south to 330 mm in the north and nearly all occur in the winter. On the east side of the valley, irrigation water is mostly derived from the Sierra snow melt. On the west side, water is imported from the northern part of the state through the Sacramento Delta and a network of canals and aqueducts. Ground water is also used for both east and west sides of the valley to supplement surface water sources, especially during droughts. After years of intense irrigation, a number of water supply and water quality issues have emerged. They include groundwater overdraft, land subsidence, water contamination by agricultural drainage laden with selenium, salinity buildup in soil and water, nutrients contamination from fertilizers and livestock production, competition for water with megalopolis and environmental use and restoration. All these problems are intensified by the effect of climate change that has already taken place and other geological hazards, such as earthquakes that can bring the water supply system to a complete halt. In addition to scientific and technical considerations, solutions for these complex issues necessarily involve management planning, public policy and actions. Currently, they include furloughing marginally productive lands, groundwater recharge and banking, water reuse and recycle, salinity and nutrient management, integrated regional water management planning, and public education and outreach. New laws have been enacted to better monitor groundwater elevations, and new bond measures to improve storage, infrastructures, and reliability, have been placed on the public ballot. The presentation will discuss these complex water issues.

  8. Factors Influencing Surface Runoff and Hydrologic Connectivity on an Agricultural Hillslope in Central Pennsylvania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved understanding of surface hydrologic processes is central to the targeted application of agricultural management practices for water quality protection. Factors influencing surface runoff production and hydrologic connectivity were explored at three landscape positions on a single hillslope...

  9. Factors affecting the stable isotopes ratios in groundwater impacted by intense agricultural practices: A case study from the Nile Valley of Egypt.

    PubMed

    Mohammed, Abdel Mawgoud; Krishnamurthy, R V; Kehew, Alan E; Crossey, Laura J; Karlstrom, Karl K

    2016-12-15

    The monitoring of stable isotopes (δ(18)O and δ(2)H) in water can provide a sensitive indicator of water loss by evaporation. We obtained water samples from surface water and groundwater from both the young and old alluvial plains in the central part of the Nile Valley of Egypt. Groundwater is the only source for irrigation in the old alluvial plains while both surface water (River Nile and irrigation canals) and groundwater are used in the young alluvial plain. Results showed different isotopic compositions between each group of samples and hydrologic connections between shallow groundwater and surface water in the young alluvial plain. The δ(18)O and δ(2)H relationship of the samples collected from the desert areas of the old alluvial plains below agricultural lands define an evaporation line with a slope of 4.5 and low deuterium excess of <-14‰. These values can be attributed to return flow of irrigation water that has been subjected to evaporative processes, further amplified by intense agricultural practices. Average evaporative losses were estimated to be between 31% and 36%.

  10. The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields (2011 Final)

    EPA Science Inventory

    This report assesses the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the central Appalachian coalfields. These coalfields cover about 48,000 square kilometers (122 million acres) in West Virginia, Kentucky, Virgi...

  11. The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields (External Review Draft)

    EPA Science Inventory

    This report assesses the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the Central Appalachian Coalfields. Our review focused on the aquatic impacts of mountaintop removal coal mining, which, as its name suggests, ...

  12. Institutions, Social Capital and Agricultural Change in Central and Eastern Europe

    ERIC Educational Resources Information Center

    Slangen, Louis H. G.; van Kooten, G. Cornelis; Suchanek, Pavel

    2004-01-01

    Data from a survey of agricultural stakeholders are used to demonstrate that institutions and social capital play an important role in agricultural success in Central and Eastern European Countries (CEECs). Protection of private property, freedom of exchange, consistency in monitoring environmental laws, governments that act neutrally and are not…

  13. Characterizing the ozone formation potential of agricultural sources in California's San Joaquin Valley: A computational and experimental approach

    NASA Astrophysics Data System (ADS)

    Howard, Cody Jerome

    The global pattern of expanding urban centers and increasing agricultural intensity is leading to more frequent interactions between air pollution emissions from urban and agricultural sources. The confluence of these emissions that traditionally have been separated by hundreds of kilometers is creating new air quality challenges in numerous regions across the United States. An area of particular interest is California's San Joaquin Valley (SJV), which has an agricultural output higher than many countries, a rapidly expanding human population, and ozone concentrations that are already higher than many dense urban areas. New regulations in the SJV restrict emissions of reactive organic gases (ROG) from animal sources in an attempt to meet Federal and State ozone standards designed to protect human health. A transportable "smog" chamber was developed and tested to directly measure the ozone formation potential of a variety of agricultural emissions in representative urban and rural atmospheres. After validation of the experimental procedure, four animal types were examined: beef cattle, dairy cattle, swine, and poultry, as well as six commonly used animal feeds: cereal silage (wheat grain and oat grain), alfalfa silage, corn silage, high moisture ground corn, almond shells, almond hulls, and total mixed ration. The emitted ROG composition was also measured so that the theoretical incremental reactivity could be calculated for a variety of atmospheres and directly compared with the measured ozone formation potential (OFP) under the experimental conditions. A computational model was created based on a modified form of the Caltech Atmospheric Chemistry Mechanism and validated against experimental results. After validation, the computational model was used to predict OFP across a range of NOx and ROG concentrations. The ROG OFP measurements combined with adjusted agricultural ROG emissions inventory estimates were used to predict the actual ozone production in the SJV

  14. Paleoseismology of a possible fault scarp in Wenas Valley, central Washington

    USGS Publications Warehouse

    Sherrod, Brian L.; Barnett, Elizabeth A.; Knepprath, Nichole; Foit, Franklin F.

    2013-01-01

    In October 2009, two trenches excavated across an 11-kilometer-long scarp at Wenas Valley in central Washington exposed evidence for late Quaternary deformation. Lidar imagery of the Wenas Valley illuminated the west-northwest-trending, 2- to 8-meter-high scarp as it bisected alluvial fans developed at the mouths of canyons along the south side of Umtanum Ridge. The alignment of the scarp and aeromagnetic lineaments suggested that the scarp may be a product of and controlled by the same tectonic structure that produced the magnetic lineaments. Several large landslides mapped in the area demonstrated the potential for large mass-wasting events in the area. In order to test whether the scarp was the result of an earthquake-generated surface rupture or a landslide, trenches were excavated at Hessler Flats and McCabe Place. The profiles of bedrock and soil stratigraphy that underlie the scarp in each trench were photographed, mapped, and described, and a sequence of depositional and deformational events established for each trench. The McCabe Place trench exposed a sequence of volcaniclastic deposits overlain by soils and alluvial deposits separated by three unconformities. Six normal faults and two possible reverse faults deformed the exposed strata. Crosscutting relations indicated that up to five earthquakes occurred on a blind reverse fault, and a microprobe analysis of lapilli suggested that the earliest faulting occurred after 47,000 years before present. The Hessler Flat trench exposure revealed weathered bedrock that abuts loess and colluvium deposits and is overlain by soil, an upper sequence of loess, and colluvium. The latter two units bury a distinctive paloesol.

  15. Groundwater Quality and Nitrogen Use Efficiency in Nebraska's Central Platte River Valley.

    PubMed

    Ferguson, Richard B

    2015-03-01

    Groundwater nitrate contamination has been an issue in the Platte River Valley of Nebraska since the 1960s, with groundwater nitrate-N concentrations frequently in excess of 10 mg L. This article summarizes education and regulatory efforts to reduce the environmental impact of irrigated crop production in the Platte River Valley. In 1988, a Groundwater Management Area (GWMA) was implemented in the Central Platte Natural Resources District to encourage adoption of improved management practices. Since 1988, there have been steady declines in average groundwater nitrate-N concentrations of about 0.15 mg NO-N L yr in much of the GWMA (from 19 to 15 mg NO-N L). However, N use efficiency (NUE) (partial factor productivity for N [PFP]) has increased very little from 1988 to 2012 (60-65 kg grain kg N), whereas statewide PFP increased from 49 to 67 kg grain kg N in the same period. Although growers are encouraged to credit N from sources besides fertilizer (e.g., soil residual, legumes, irrigation water, and manure), confidence in and use of credits tended to decrease as credits became larger; there was a tendency toward an average N rate regardless of credit-based recommendations. This information, coupled with data from other studies, suggests that much of the decline in groundwater nitrate can be attributed to improved irrigation management-especially conversion from furrow to sprinkler irrigation-and to a lesser extent to improved timing of N application. The development and adoption of improved N management practices, such as fertigation, controlled-release N formulation, and use of crop canopy sensors for in-season N application may be required for further significant NUE gains in these irrigated systems.

  16. The Chako antiform: A folded segment of the Greater Himalayan sequence, Nar valley, Central Nepal Himalaya

    NASA Astrophysics Data System (ADS)

    Gleeson, Thomas P.; Godin, Laurent

    2006-09-01

    Recent and previously published mapping in the Nar valley, north of the Annapurna massif in central Nepal, recognised an enigmatic metamorphic culmination of the Greater Himalayan sequence, surrounded by rocks correlated with the Tethyan sedimentary sequence. The map area is re-interpreted as two structural levels within the Greater Himalayan sequence. The Lower Level is correlated to the well-studied Greater Himalayan sequence of the Annapurna region, based on characteristic rock types, high-strain zones with south-verging shear-sense indicators, and high-grade metamorphism. The rocks of the Upper Level, previously mapped as the sub-greenschist or zeolite facies Tethyan sedimentary sequence, are garnet-bearing schists. Petrography and garnet-biotite thermometry suggest the Upper Level equilibrated at amphibolite facies (500-650 °C). These results support the recent contention that the Upper Level rocks are a component of the Greater Himalayan sequence, and thus indicate that components of the Himalayan metamorphic core vary considerably along strike. Structural, metamorphic and age constraints are integrated into a cohesive regional tectonometamorphic model. The Lower and Upper Levels both experienced D 1 deformation and peak metamorphism before ˜20 Ma. The Lower and Upper Levels were juxtaposed along the synmetamorphic Chame detachment after 20 Ma during retrograde metamorphism. After ˜19 Ma, the Phu detachment placed the unmetamorphosed Tethyan sedimentary sequence above the Lower and Upper Levels. The entire package was then subsequently folded, after 19 Ma, by a non-cylindrical antiform-synform pair with a ˜25 km wavelength creating an apparent dome. The proposed tectonometamorphic model reconciles previously contradictory interpretations of the transition between metamorphic core and overlying sediments in the Nar valley.

  17. Demographics and movements of least terns and piping plovers in the Central Platte River Valley, Nebraska

    USGS Publications Warehouse

    Roche, Erin A.; Sherfy, Mark H.; Ring, Megan M.; Shaffer, Terry L.; Anteau, Michael J.; Stucker, Jennifer H.

    2016-08-09

    The Central Platte River Valley provides breeding habitat for a variety of migratory birds, including federally endangered interior least terns (Sternula antillarum; least tern) and threatened piping plovers (Charadrius melodus). Since 2009, researchers have collected demographic data on both species that span their lifecycle (that is, from egg laying through survival of adults). Demographic data were used to estimate vital rates (for example, nest survival, chick survival, and so on) for both species and assess how these vital rates were related to type and age of nesting habitat. Nest survival of both species was unrelated to the age of the site a nest was initiated on. Piping plover chick survival to fledging age was not related to the age of the site it was hatched at, however, the probability of a least tern chick surviving to fledging was higher at older sites. In general there were fewer piping plover nests than least tern nests found at sites created through either the physical construction of a new site or new vegetation management regimes, during 2009–14.Mean daily least tern nest survival was 0.9742 (95-percent confidence interval [CI]: 0.9692–0.9783) and cumulative nest survival was 0.59 (95-percent CI: 0.53–0.65). Mean daily least tern chick survival was 0.9602 (95-percent CI: 0.9515–0.9673) and cumulative survival to fledging was 0.54 (95-percent CI = 0.48–0.61). Annual apparent survival rates were estimated at 0.42 (95-percent CI = 0.22–0.64) for adult least terns nesting in the Central Platte River Valley and an apparent survival rate of 0.14 (95-pecent CI = 0.04–0.41) for juvenile least terns. The number of least tern nests present at sites created during 2009–14 was associated with the age of the site; more least tern nests were associated with older sites. During 2009–14, there were four (less than 1 percent of all chicks marked) least tern chicks hatched from the Central Platte River Valley that were subsequently captured on

  18. Prediction and visualization of redox conditions in the groundwater of Central Valley, California

    NASA Astrophysics Data System (ADS)

    Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, JoAnn M.

    2017-03-01

    Regional-scale, three-dimensional continuous probability models, were constructed for aspects of redox conditions in the groundwater system of the Central Valley, California. These models yield grids depicting the probability that groundwater in a particular location will have dissolved oxygen (DO) concentrations less than selected threshold values representing anoxic groundwater conditions, or will have dissolved manganese (Mn) concentrations greater than selected threshold values representing secondary drinking water-quality contaminant levels (SMCL) and health-based screening levels (HBSL). The probability models were constrained by the alluvial boundary of the Central Valley to a depth of approximately 300 m. Probability distribution grids can be extracted from the 3-D models at any desired depth, and are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions. Models were constructed using a Boosted Regression Trees (BRT) machine learning technique that produces many trees as part of an additive model and has the ability to handle many variables, automatically incorporate interactions, and is resistant to collinearity. Machine learning methods for statistical prediction are becoming increasing popular in that they do not require assumptions associated with traditional hypothesis testing. Models were constructed using measured dissolved oxygen and manganese concentrations sampled from 2767 wells within the alluvial boundary of the Central Valley, and over 60 explanatory variables representing regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrologic properties. Models were trained on a USGS dataset of 932 wells, and evaluated on an independent hold-out dataset of 1835 wells from the California Division of Drinking Water. We used cross-validation to assess the predictive performance of

  19. Prediction and visualization of redox conditions in the groundwater of Central Valley, California

    USGS Publications Warehouse

    Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, JoAnn M.

    2017-01-01

    Regional-scale, three-dimensional continuous probability models, were constructed for aspects of redox conditions in the groundwater system of the Central Valley, California. These models yield grids depicting the probability that groundwater in a particular location will have dissolved oxygen (DO) concentrations less than selected threshold values representing anoxic groundwater conditions, or will have dissolved manganese (Mn) concentrations greater than selected threshold values representing secondary drinking water-quality contaminant levels (SMCL) and health-based screening levels (HBSL). The probability models were constrained by the alluvial boundary of the Central Valley to a depth of approximately 300 m. Probability distribution grids can be extracted from the 3-D models at any desired depth, and are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions.Models were constructed using a Boosted Regression Trees (BRT) machine learning technique that produces many trees as part of an additive model and has the ability to handle many variables, automatically incorporate interactions, and is resistant to collinearity. Machine learning methods for statistical prediction are becoming increasing popular in that they do not require assumptions associated with traditional hypothesis testing. Models were constructed using measured dissolved oxygen and manganese concentrations sampled from 2767 wells within the alluvial boundary of the Central Valley, and over 60 explanatory variables representing regional-scale soil properties, soil chemistry, land use, aquifer textures, and aquifer hydrologic properties. Models were trained on a USGS dataset of 932 wells, and evaluated on an independent hold-out dataset of 1835 wells from the California Division of Drinking Water. We used cross-validation to assess the predictive performance of

  20. Rift Valley Fever Virus Circulating among Ruminants, Mosquitoes and Humans in the Central African Republic

    PubMed Central

    Nakouné, Emmanuel; Kamgang, Basile; Berthet, Nicolas; Manirakiza, Alexandre; Kazanji, Mirdad

    2016-01-01

    Background Rift Valley fever virus (RVFV) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in East Africa. Infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. Humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the Aedes and Culex genuses. Although the cycle of RVFV infection in savannah regions is well documented, its distribution in forest areas in central Africa has been poorly investigated. Methodology/Principal Findings To evaluate current circulation of RVFV among livestock and humans living in the Central African Republic (CAR), blood samples were collected from sheep, cattle, and goats and from people at risk, such as stock breeders and workers in slaughterhouses and livestock markets. The samples were tested for anti-RVFV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. We also sequenced the complete genomes of two local strains, one isolated in 1969 from mosquitoes and one isolated in 1985 from humans living in forested areas. The 1271 animals sampled comprised 727 cattle, 325 sheep, and 219 goats at three sites. The overall seroprevalence of anti-RVFV IgM antibodies was 1.9% and that of IgG antibodies was 8.6%. IgM antibodies were found only during the rainy season, but the frequency of IgG antibodies did not differ significantly by season. No evidence of recent RVFV infection was found in 335 people considered at risk; however, 16.7% had evidence of past infection. Comparison of the nucleotide sequences of the strains isolated in the CAR with those isolated in other African countries showed that they belonged to the East/Central African cluster. Conclusion and significance This study confirms current circulation of RVFV in CAR. Further studies are needed to determine the potential vectors involved and the virus reservoirs. PMID:27760144

  1. Spatial variation of soil salinity in the Mexicali Valley, Mexico: application of a practical method for agricultural monitoring.

    PubMed

    Judkins, Gabriel; Myint, Soe

    2012-09-01

    The degradation of irrigated lands through the process of soil salinization, or the buildup of salts in the soil, has hampered recent increases in agricultural productivity and threatens the sustainability of large-scale cultivation in critical agricultural regions of the world. Rapid detection of soil salinity on a regional basis has been identified as key for effective mitigation of such land degradation. The ability to detect regional patterns of soil salinity at an accuracy sufficient for regional-scale resource management is demonstrated using Landsat 5 Thematic Mapper (TM) imagery. A case study of the Mexicali Valley of Baja California, Mexico was selected due to the region's agricultural significance and concern for future soil salinity increases. Surface soil salinity was mapped using georeferenced field measurements of electrical conductivity (EC), collected concurrently with Landsat 5 TM imagery. Correlations between EC measurements and common indices derived from the satellite imagery were used to produce a model of soil salinity through regression analysis. Landsat band 7, TNDVI, PCA 1, Tasseled Cap 3 and Tasseled Cap 5 were found to offer the most promising correlations with surface soil salinity. Generally low levels of soil salinity were detected, however, distinct areas of elevated surface salinity were detected at levels potentially impacting sensitive crops cultivated within the region. The difficulty detecting low levels of salinity and the mid-range spatial resolution of Landsat 5 TM imagery restrict the applicability of this methodology to the study of broad regional patterns of degradation most appropriate for use by regional resource managers.

  2. Spatial Variation of Soil Salinity in the Mexicali Valley, Mexico: Application of a Practical Method for Agricultural Monitoring

    NASA Astrophysics Data System (ADS)

    Judkins, Gabriel; Myint, Soe

    2012-09-01

    The degradation of irrigated lands through the process of soil salinization, or the buildup of salts in the soil, has hampered recent increases in agricultural productivity and threatens the sustainability of large-scale cultivation in critical agricultural regions of the world. Rapid detection of soil salinity on a regional basis has been identified as key for effective mitigation of such land degradation. The ability to detect regional patterns of soil salinity at an accuracy sufficient for regional-scale resource management is demonstrated using Landsat 5 Thematic Mapper (TM) imagery. A case study of the Mexicali Valley of Baja California, Mexico was selected due to the region's agricultural significance and concern for future soil salinity increases. Surface soil salinity was mapped using georeferenced field measurements of electrical conductivity (EC), collected concurrently with Landsat 5 TM imagery. Correlations between EC measurements and common indices derived from the satellite imagery were used to produce a model of soil salinity through regression analysis. Landsat band 7, TNDVI, PCA 1, Tasseled Cap 3 and Tasseled Cap 5 were found to offer the most promising correlations with surface soil salinity. Generally low levels of soil salinity were detected, however, distinct areas of elevated surface salinity were detected at levels potentially impacting sensitive crops cultivated within the region. The difficulty detecting low levels of salinity and the mid-range spatial resolution of Landsat 5 TM imagery restrict the applicability of this methodology to the study of broad regional patterns of degradation most appropriate for use by regional resource managers.

  3. Sustainable smallholder poultry interventions to promote food security and social, agricultural, and ecological resilience in the Luangwa Valley, Zambia.

    PubMed

    Dumas, Sarah E; Lungu, Luke; Mulambya, Nathan; Daka, Whiteson; McDonald, Erin; Steubing, Emily; Lewis, Tamika; Backel, Katherine; Jange, Jarra; Lucio-Martinez, Benjamin; Lewis, Dale; Travis, Alexander J

    2016-06-01

    In Zambia's Luangwa Valley, highly variable rainfall and lack of education, agricultural inputs, and market access constrain agricultural productivity, trapping smallholder farmers in chronic poverty and food insecurity. Human and animal disease (e.g. HIV and Newcastle Disease, respectively), further threaten the resilience of poor families. To cope with various shocks and stressors, many farmers employ short-term coping strategies that threaten ecosystem resilience. Community Markets for Conservation (COMACO) utilizes an agribusiness model to alleviate poverty and food insecurity through conservation farming, market development and value-added food production. COMACO promotes household, agricultural and ecological resilience along two strategic lines: improving recovery from shocks (mitigation) and reducing the risk of shock occurrence. Here we focus on two of COMACO's poultry interventions and present data showing that addressing health and management constraints within the existing village poultry system resulted in significantly improved productivity and profitability. However, once reliable productivity was achieved, farmers preferred to sell chickens rather than eat either the birds or their eggs. Sales of live birds were largely outside the community to avoid price suppression; in contrast, the sale of eggs from community-operated, semi-intensive egg production facilities was invariably within the communities. These facilities resulted in significant increases in both producer income and community consumption of eggs. This intervention therefore has the potential to improve not only producers' economic resilience, but also resilience tied to the food security and physical health of the entire community.

  4. Early Pleistocene Glacial Lake Lesley, West Branch Susquehanna River valley, central Pennsylvania

    NASA Astrophysics Data System (ADS)

    Ramage, Joan M.; Gardner, Thomas W.; Sasowsky, Ira D.

    1998-02-01

    Laurentide glaciers extended into north central Pennsylvania repeatedly during at least the last 2 million years. Early Pleistocene glaciation extended farther south into central Pennsylvania than any subsequent glaciation, reaching the West Branch Susquehanna River (WBSR) valley. Early Pleistocene ice dammed the northeast-flowing West Branch Susquehanna River at Williamsport, forming Glacial Lake Lesley, a 100-km-long proglacial lake. In this paper, we present compelling evidence for the lake and its age. Maximum lake volume (˜ 100 km 3) was controlled by the elevation of the lowest drainage divide, ˜ 340 m above sea level at Dix, Pennsylvania. Stratified deposits at McElhattan and Linden are used to reconstruct depositional environments in Glacial Lake Lesley. A sedimentary section 40 m thick at McElhattan fines upward from crossbedded sand to fine, wavy to horizontally laminated clay, consistent with lake deepening and increasing distance from the sediment source with time. At Linden, isolated cobbles, interpreted as dropstones, locally deform glacio-lacustrine sediment. We use paleomagnetism as an age correlation tool in the WBSR valley to correlate contemporaneous glaciofluvial and proglacial lacustrine sediments. Reversed remanent polarity in finely-laminated lacustrine clay and silt at McElhattan ( I = 20.4°, D = 146.7°, α95 = 17.7°) and in interbedded silt and sand at Linden ( I = 55.3°, D = 175.2°, α95 = 74.6°) probably corresponds to the latter part of the Matuyama Reversed Polarity Chron, indicating an age between ˜ 770 and ˜ 970 ka. At McElhattan, a diamicton deformed the finely laminated silt and clay by loading and partial fluidization during or soon after lake drainage. As a result, the deformed clay at McElhattan lacks discrete bedding and records a different characteristic remanent magnetism from underlying, undeformed beds. This difference indicates that the characteristic remanent magnetism is detrital. An electrical resistivity

  5. A statistical learning framework for groundwater nitrate models of the Central Valley, California, USA

    USGS Publications Warehouse

    Nolan, Bernard T.; Fienen, Michael N.; Lorenz, David L.

    2015-01-01

    We used a statistical learning framework to evaluate the ability of three machine-learning methods to predict nitrate concentration in shallow groundwater of the Central Valley, California: boosted regression trees (BRT), artificial neural networks (ANN), and Bayesian networks (BN). Machine learning methods can learn complex patterns in the data but because of overfitting may not generalize well to new data. The statistical learning framework involves cross-validation (CV) training and testing data and a separate hold-out data set for model evaluation, with the goal of optimizing predictive performance by controlling for model overfit. The order of prediction performance according to both CV testing R2 and that for the hold-out data set was BRT > BN > ANN. For each method we identified two models based on CV testing results: that with maximum testing R2 and a version with R2 within one standard error of the maximum (the 1SE model). The former yielded CV training R2 values of 0.94–1.0. Cross-validation testing R2 values indicate predictive performance, and these were 0.22–0.39 for the maximum R2 models and 0.19–0.36 for the 1SE models. Evaluation with hold-out data suggested that the 1SE BRT and ANN models predicted better for an independent data set compared with the maximum R2 versions, which is relevant to extrapolation by mapping. Scatterplots of predicted vs. observed hold-out data obtained for final models helped identify prediction bias, which was fairly pronounced for ANN and BN. Lastly, the models were compared with multiple linear regression (MLR) and a previous random forest regression (RFR) model. Whereas BRT results were comparable to RFR, MLR had low hold-out R2 (0.07) and explained less than half the variation in the training data. Spatial patterns of predictions by the final, 1SE BRT model agreed reasonably well with previously observed patterns of nitrate occurrence in groundwater of the Central Valley.

  6. Sensitivity of agricultural runoff to climate change in the San Joaquin Valley watershed of California

    NASA Astrophysics Data System (ADS)

    Ficklin, D. L.; Luo, Y.; Gatzke, S. E.; Zhang, M.

    2008-12-01

    The quantification of the hydrological response to climate change and increasing atmospheric CO2 concentrations is required for the proper management of agricultural systems and water resources. This study simulated variations in CO2, temperature and precipitation to quantify the hydrologic response in an intensive agricultural system. The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on agricultural runoff in the San Joaquin watershed in California. The results of this study suggest that atmospheric CO2, precipitation, and temperature changes have significant effects on the yield of sediment, nitrate, total phosphorus, and two pesticides (diazinon and chlorypyrifos) chosen for consideration. As expected, precipitation had a greater impact on agricultural runoff compared to changes in either CO2 concentration or temperature. A change in precipitation of ±10% and ±20% generally altered agricultural runoff proportionally. In comparison to present day reference scenarios, a simulated increase in CO2 concentration while holding temperature and precipitation constant resulted in an increased nitrate, total phosphorus, and chlorpyrifos yield of 4.2, 7.8, and 6.4%, respectively, and a decreased sediment and diazinon yield of 6.3 and 6.4%, respectively. A temperature increase with no precipitation or CO2 concentration change caused a decrease for all agricultural runoff components. Results from this study provide valuable insight into the effects of various climate change scenarios on agricultural runoff and can direct policy makers and agricultural stakeholders in their efforts to create and comply with water quality legislation in a rapidly changing environment.

  7. Horticulture Materials for Agricultural Education Programs. Core Agricultural Education Curriculum, Central Cluster.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Office of Agricultural Communications and Education.

    This curriculum guide contains five units with relevant problem areas for horticulture. These problem areas have been selected as suggested areas of study to be included in a core curriculum for secondary students enrolled in an agricultural education program. Each problem area includes some or all of the following components: related problem…

  8. Intensive rice agriculture deteriorates the quality of shallow groundwater in a typical agricultural catchment in subtropical central China.

    PubMed

    Wang, Yi; Li, Yuyuan; Li, Yong; Liu, Feng; Liu, Xinliang; Gong, Dianlin; Ma, Qiumei; Li, Wei; Wu, Jinshui

    2015-09-01

    High nitrogen (N) concentrations in rural domestic water supplies have been attributed to excessive agricultural N leaching into shallow groundwater systems; therefore, it is important to determine the impact of agriculture (e.g., rice production) on groundwater quality. To understand the impact of agricultural land use on the N concentrations in the shallow groundwater in subtropical central China, a large observation program was established to observe ammonium-N (NH4-N), nitrate-N (NO3-N), and total N (TN) concentrations in 161 groundwater observation wells from April 2010 to November 2012. The results indicated that the median values of NH4-N, NO3-N, and TN concentrations in the groundwater were 0.15, 0.39, and 1.38 mg N L(-1), respectively. A total of 36.3 % of the water samples were categorized as NH4-N pollution, and only a small portion of the samples were categorized as NO3-N pollution, based on the Chinese Environmental Quality Standards for Groundwater of GB/T 14848-93 (General Administration of Quality Supervision of China, 1993). These results indicated of moderate groundwater NH4-N pollution, which was mainly attributed to intensive rice agriculture with great N fertilizer application rates in the catchment. In addition, tea and vegetable fields showed higher groundwater NO3-N and TN concentrations than other agricultural land use types. The factorial correspondence analysis (FCA) suggested that the flooded agricultural land use types (e.g., single-rice and double-rice) had potential to impose NH4-N pollution, particularly in the soil exhausting season during from July to October. And, the great N fertilizer application rates could lead to a worse NO3-N and TN pollution in shallow groundwater. Hence, to protect groundwater quality and minimize NH4-N pollution, managing optimal fertilizer application and applying appropriate agricultural land use types should be implemented in the region.

  9. Rock avalanche deposits in Alai Valley, Central Asia: misinterpretation of glacial record

    NASA Astrophysics Data System (ADS)

    Reznichenko, Natalya; Davies, Tim; Robinson, Tom; De Pascale, Gregory

    2013-04-01

    The reconstruction of Quaternary glaciations has been restricted by conventional approaches with resulting contradictions in interpretation of the regional glacial record, that recently have been subjected to critical re-evaluation. Along with uncertainties in dating techniques and their applicability to particular landforms (Kirkbride and Winkler, 2012), it has recently been demonstrated that the presence of rock avalanche debris in a landform can be unequivocally detected; this allows for the first time definitive identification of and distinction between glacial moraines and landslide deposits. It also identifies moraines that have formed due to rock avalanche deposition on glaciers, possibly with no associated climatic signal (Reznichenko et al., 2012). Confusion between landslide deposits and moraines is evident for ranges in Central Asia (e.g., Hewitt, 1999) where the least-studied glacial record is selectively correlated with established glacial chronologies in Alpine ranges, which in turn masks the actual glacial extent and their responses to climate change, tectonics and landsliding activity. We describe examples in the glaciated Alai Valley, large intermountain depression between the Zaalay Range of the Northern Pamir and the Alay Range of the Southern Tien-Shan, showing that some large Quaternary deposits classically interpreted as moraines are of rock avalanche origin. Sediment from these deposits has been tested for the presence of agglomerates that are only produced under high stress conditions during rock avalanche motion, and are absent from glacial sediments (Reznichenko et al., 2012). This reveals that morphologically-similar deposits have radically different geneses: rock avalanche origin for a deposit in the Komansu river catchment and glacial origin for deposits in the Ashiktash and Kyzylart catchments. The enormous Komansu rock avalanche deposit, probably triggered by a rupture of the Main Pamir thrust, currently covers about 100 km2 with a

  10. Hydrogeologic framework and occurrence, movement, and chemical characterization of groundwater in Dixie Valley, west-central Nevada

    USGS Publications Warehouse

    Huntington, Jena M.; Garcia, C. Amanda; Rosen, Michael R.

    2014-01-01

    Dixie Valley, a primarily undeveloped basin in west-central Nevada, is being considered for groundwater exportation. Proposed pumping would occur from the basin-fill aquifer. In response to proposed exportation, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and Churchill County, conducted a study to improve the understanding of groundwater resources in Dixie Valley. The objective of this report is to characterize the hydrogeologic framework, the occurrence and movement of groundwater, the general water quality of the basin-fill aquifer, and the potential mixing between basin-fill and geothermal aquifers in Dixie Valley. Various types of geologic, hydrologic, and geochemical data were compiled from previous studies and collected in support of this study. Hydrogeologic units in Dixie Valley were defined to characterize rocks and sediments with similar lithologies and hydraulic properties influencing groundwater flow. Hydraulic properties of the basin-fill deposits were characterized by transmissivity estimated from aquifer tests and specific-capacity tests. Groundwater-level measurements and hydrogeologic-unit data were combined to create a potentiometric surface map and to characterize groundwater occurrence and movement. Subsurface inflow from adjacent valleys into Dixie Valley through the basin-fill aquifer was evaluated using hydraulic gradients and Darcy flux computations. The chemical signature and groundwater quality of the Dixie Valley basin-fill aquifer, and potential mixing between basin-fill and geothermal aquifers, were evaluated using chemical data collected from wells and springs during the current study and from previous investigations. Dixie Valley is the terminus of the Dixie Valley flow system, which includes Pleasant, Jersey, Fairview, Stingaree, Cowkick, and Eastgate Valleys. The freshwater aquifer in the study area is composed of unconsolidated basin-fill deposits of Quaternary age. The basin-fill hydrogeologic unit

  11. Simulation of water-table response to management alternatives, central part of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, K.R.; Phillips, S.P.

    1992-01-01

    The occurrence of selenium in agricultural drainwater in the central pan of the western San Joaquin Valley, California, has focused concern on alternatives other than agricultural drains for managing shallow, poor-quality ground water. A transient, three-dimensional, finite-difference ground-water flow model was developed to assess the response of the water table to various management alternatives. The modeled area is 551 square miles and includes the semiconfined and confined zones above and below the Corcoran Clay Member of the Tulare Formation of Pleistocene age. The model was calibrated using hydrologic data from 1972 to 1988 and was able to reproduce the average change in water-table altitude to within 4 percent. The calibrated model was extended to forecast to the year 2040 for various management alternatives including maintenance of present practices, land retirement, reduced recharge, increased ground-water pumping, combinations of these alternatives, and five alternatives proposed by the U.S. Bureau of Reclamation. The model indicates that if current rates of recharge and pumping (as determined from an analysis of 1980 water-budget data) are maintained, the total area subject to bare-soil evaporation will increase by more than 50 percent and drainflow will increase by 20 percent. Model results indicate that retirement of land will result in a water-table decline beneath the area retired, but the effect on adjacent areas will be small to negligible. The effects of reducing recharge or increasing ground-water pumping vary with the magnitude of the change relative to average conditions and the size of the area managed. The area of land subject to bare-soil evaporation and the amount of drainflow in the model area can be reduced by more than 40 and 50 percent, respectively, if (1) recharge is reduced by 40 percent (about 0.3 foot per year) in areas that currently use only surface water, and by 15 percent (an average of about O. 1 foot per year) in the

  12. Application of pesticide transport model for simulating diazinon runoff in California’s central valley

    NASA Astrophysics Data System (ADS)

    Joyce, Brian A.; Wallender, Wesley W.; Mailapalli, Damodhara R.

    2010-12-01

    Dormant spray application of pesticides to almond and other stone fruit orchards is the main source of diazinon during the winter in California's central valley. Understanding the pesticide transport and the tradeoffs associated with the various management practices is greatly facilitated by the use of physically-based contaminant transport models. In this study, performance of Joyce's et al. (2008) pesticide transport model was evaluated using experimental data collected from two ground treatments such as resident vegetation and bare soil. The model simulation results obtained in calibration and validation process were analyzed for pesticide concentration and total load. The pesticide transport model accurately predicted the pesticide concentrations and total load in the runoff from bare field and was capable of simulating chemical responses to rainfall-runoff events. In case of resident vegetation, the model results exhibited a larger range of variation than was observed in the bare soil simulations due to increased model parameterization with the addition of foliage and thatch compartments. Furthermore, the model was applied to study the effect of runoff lag time, extent of crop cover, organic content of soil and post-application irrigation on the pesticide peak concentration and total load. Based on the model results, recommendations were suggested to growers prior to implementing certain management decisions to mitigate diazinon transport in the orchard's spray runoff.

  13. Comparison of Two Parametric Methods to Estimate Pesticide Mass Loads in California's Central Valley

    USGS Publications Warehouse

    Saleh, D.K.; Lorenz, D.L.; Domagalski, J.L.

    2011-01-01

    Mass loadings were calculated for four pesticides in two watersheds with different land uses in the Central Valley, California, by using two parametric models: (1) the Seasonal Wave model (SeaWave), in which a pulse signal is used to describe the annual cycle of pesticide occurrence in a stream, and (2) the Sine Wave model, in which first-order Fourier series sine and cosine terms are used to simulate seasonal mass loading patterns. The models were applied to data collected during water years 1997 through 2005. The pesticides modeled were carbaryl, diazinon, metolachlor, and molinate. Results from the two models show that the ability to capture seasonal variations in pesticide concentrations was affected by pesticide use patterns and the methods by which pesticides are transported to streams. Estimated seasonal loads compared well with results from previous studies for both models. Loads estimated by the two models did not differ significantly from each other, with the exceptions of carbaryl and molinate during the precipitation season, where loads were affected by application patterns and rainfall. However, in watersheds with variable and intermittent pesticide applications, the SeaWave model is more suitable for use on the basis of its robust capability of describing seasonal variation of pesticide concentrations. ?? 2010 American Water Resources Association. This article is a US Government work and is in the public domain in the USA.

  14. Comparison of two parametric methods to estimate pesticide mass loads in California's Central Valley

    USGS Publications Warehouse

    Saleh, Dina K.; Lorenz, David L.; Domagalski, Joseph L.

    2011-01-01

    Mass loadings were calculated for four pesticides in two watersheds with different land uses in the Central Valley, California, by using two parametric models: (1) the Seasonal Wave model (SeaWave), in which a pulse signal is used to describe the annual cycle of pesticide occurrence in a stream, and (2) the Sine Wave model, in which first-order Fourier series sine and cosine terms are used to simulate seasonal mass loading patterns. The models were applied to data collected during water years 1997 through 2005. The pesticides modeled were carbaryl, diazinon, metolachlor, and molinate. Results from the two models show that the ability to capture seasonal variations in pesticide concentrations was affected by pesticide use patterns and the methods by which pesticides are transported to streams. Estimated seasonal loads compared well with results from previous studies for both models. Loads estimated by the two models did not differ significantly from each other, with the exceptions of carbaryl and molinate during the precipitation season, where loads were affected by application patterns and rainfall. However, in watersheds with variable and intermittent pesticide applications, the SeaWave model is more suitable for use on the basis of its robust capability of describing seasonal variation of pesticide concentrations.

  15. Modeling nitrate at domestic and public-supply well depths in the Central Valley, California

    USGS Publications Warehouse

    Nolan, Bernard T.; Gronberg, JoAnn M.; Faunt, Claudia C.; Eberts, Sandra M.; Belitz, Ken

    2014-01-01

    Aquifer vulnerability models were developed to map groundwater nitrate concentration at domestic and public-supply well depths in the Central Valley, California. We compared three modeling methods for ability to predict nitrate concentration >4 mg/L: logistic regression (LR), random forest classification (RFC), and random forest regression (RFR). All three models indicated processes of nitrogen fertilizer input at the land surface, transmission through coarse-textured, well-drained soils, and transport in the aquifer to the well screen. The total percent correct predictions were similar among the three models (69–82%), but RFR had greater sensitivity (84% for shallow wells and 51% for deep wells). The results suggest that RFR can better identify areas with high nitrate concentration but that LR and RFC may better describe bulk conditions in the aquifer. A unique aspect of the modeling approach was inclusion of outputs from previous, physically based hydrologic and textural models as predictor variables, which were important to the models. Vertical water fluxes in the aquifer and percent coarse material above the well screen were ranked moderately high-to-high in the RFR models, and the average vertical water flux during the irrigation season was highly significant (p < 0.0001) in logistic regression.

  16. Geochemistry of natural gas manifestions from the Upper Tiber Valley (central Italy)

    USGS Publications Warehouse

    Vaselli, O.; Tassi, F.; Minissale, A.; Capaccioni, B.; Macro, G.; Evans, William C.

    1997-01-01

    Six natural gas manifestions from the upper Tiber Valley at Caprese Michelangela and Pieve S. Stefano (Arezzo) and at Umbertide (Pertugia) localities have been analysed for major, minor, trace gas compositions, as well as for ??13C in CO2 and CH4, ??15N in N2 and 3He/4He isotopic ratios. All gas emissions are CO2-rich (???94%), with N2 contents of 4-5%. Those from Caprese and Pieve S. Stefano have very peculiar compsitions when compared to other gases from northern-central Apennines. Apart from CO2, these gases show relatively high contents of He (with crustal isotopic ratios) and medium to high temperature-related gases such as CO, H2 and C6H6. Although located quite far from the geothermal areas in Tuscany, the application of several gas geothermetric techniques suggest for these gases deep equilibrium tempratures of about 300??C. Moreover, the ??13C in CO2 and CH4 (~.4.0% and -38.0%, respectively) and the ??13N values in N2 (+0.064 to +0.84%) would seem to imply a multiple deep source for these gases.

  17. Modeling nitrate at domestic and public-supply well depths in the Central Valley, California.

    PubMed

    Nolan, Bernard T; Gronberg, JoAnn M; Faunt, Claudia C; Eberts, Sandra M; Belitz, Ken

    2014-05-20

    Aquifer vulnerability models were developed to map groundwater nitrate concentration at domestic and public-supply well depths in the Central Valley, California. We compared three modeling methods for ability to predict nitrate concentration >4 mg/L: logistic regression (LR), random forest classification (RFC), and random forest regression (RFR). All three models indicated processes of nitrogen fertilizer input at the land surface, transmission through coarse-textured, well-drained soils, and transport in the aquifer to the well screen. The total percent correct predictions were similar among the three models (69-82%), but RFR had greater sensitivity (84% for shallow wells and 51% for deep wells). The results suggest that RFR can better identify areas with high nitrate concentration but that LR and RFC may better describe bulk conditions in the aquifer. A unique aspect of the modeling approach was inclusion of outputs from previous, physically based hydrologic and textural models as predictor variables, which were important to the models. Vertical water fluxes in the aquifer and percent coarse material above the well screen were ranked moderately high-to-high in the RFR models, and the average vertical water flux during the irrigation season was highly significant (p < 0.0001) in logistic regression.

  18. Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

    NASA Technical Reports Server (NTRS)

    Lewis, Jasper; DeYoung, Russell; Ferrare, Richard; Chu, D. Allen

    2010-01-01

    Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2007. While the ground PM(sub 2.5) concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM(sub 2.5) in the winter can exceed summer PM(sub 2.5) by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures and wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Temperature inversions, especially during the winter, contribute to higher PM(sub 2.5) measurements at the surface. Measurements of the boundary layer height from lidar instruments provide valuable information need to understand the relationship between satellite measurements of optical depth and in-situ measurements of PM(sub 2.5).

  19. Genetic demography of Antioquia (Colombia) and the Central Valley of Costa Rica.

    PubMed

    Carvajal-Carmona, Luis G; Ophoff, Roel; Service, Susan; Hartiala, Jaana; Molina, Julio; Leon, Pedro; Ospina, Jorge; Bedoya, Gabriel; Freimer, Nelson; Ruiz-Linares, Andrés

    2003-05-01

    We report a comparative genetic characterization of two population isolates with parallel demographic histories: the Central Valley of Costa Rica (CVCR) and Antioquia (in northwest Colombia). The analysis of mtDNA, Y-chromosome and autosomal polymorphisms shows that Antioquia and the CVCR are genetically very similar, indicating that closely related parental populations founded these two isolates. In both populations, the male ancestry is predominantly European, whereas the female ancestry is mostly Amerind. In agreement with their isolation, the Amerindian mtDNA diversity of Antioquia and the CVCR is typical of ethnically-defined native populations and is markedly lower than in other Latin American populations. A comparison of linkage disequilibrium (LD) at 18 marker pairs in Antioquia and the CVCR shows that markers in LD in both populations are located at short genetic distances (

  20. Sex-related differences in habitat associations of wintering American Kestrels in California's Central Valley

    USGS Publications Warehouse

    Pandolfino, E.R.; Herzog, M.P.; Smith, Z.

    2011-01-01

    We used roadside survey data collected from 19 routes over three consecutive winters from 200708 to 200910 to compare habitat associations of male and female American Kestrels (Falco sparverius) in the Central Valley of California to determine if segregation by sex was evident across this region. As a species, American Kestrels showed positive associations with alfalfa and other forage crops like hay and winter wheat, as well as grassland, irrigated pasture, and rice. Habitat associations of females were similar, with female densities in all these habitats except rice significantly higher than average. Male American Kestrels showed a positive association only with grassland and were present at densities well below those of females in alfalfa, other forage crops, and grassland. Males were present in higher densities than females in most habitats with negative associations for the species, such as orchards, urbanized areas, and oak savannah. The ratio of females to males for each route was positively correlated with the overall density of American Kestrels on that route. Our findings that females seem to occupy higher quality habitats in winter are consistent with observations from elsewhere in North America. ?? 2011 The Raptor Research Foundation, Inc.

  1. Data for ground-water test hole near Butte City, Central Valley aquifer project, California

    USGS Publications Warehouse

    French, James J.; Page, R.W.; Bertoldi, G.L.

    1983-01-01

    This report provides preliminary data for the third of seven test holes drilled as part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 32, T. 19 N., R. 1 W., Glenn County, California, about one-half mile south of the town of Butte City. Drilled to a depth of 1,432 feet below land surface, the hole is cased to a depth of 82 feet and equipped with three piezometer tubes to depths of 592 feet, 968 feet, and 1,330 feet. A 5-foot well screen is at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer , and the well bore is filled between the plugs with sediment. Nine cores and 49 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, and chemical quality of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

  2. Data for ground-water test hole near Zamora, Central Valley Aquifer Project, California

    USGS Publications Warehouse

    French, J.J.; Page, R.W.; Bertoldi, G.L.

    1982-01-01

    Preliminary data are presented for the first of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 SE 1/4 sec. 34, T. 12 N. , R. 1 E., Yolo County, California, about 3 miles northeast of the town of Zamora. Drilled to a depth of 2,500 feet below land surface, the hole is cased to a depth of 190 feet and equipped with three piezometer tubes to depths of 947, 1,401, and 2,125 feet. A 5-foot well screen is at the bottom of each piezometer. Eighteen cores and 68 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, diatom identification, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

  3. Data for ground-water test hole near Nicolaus, Central Valley aquifer project, California

    USGS Publications Warehouse

    French, James J.; Page, R.W.; Bertoldi, Gilbert L.

    1983-01-01

    Preliminary data are provided for the third of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 2, T.12N., R.3E., Sutter County, California, about 1 1/2 miles northwest of the town of Nicolaus. Drilled to a depth of 1,150 feet below land surface, the hole is cased to a depth of 100 feet and equipped with three piezometer tubes to depths of 311, 711, and 1,071 feet. A 5-foot well screen is set in sand at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer, and the well bore is filled between the plugs with sediment. Thirty-one cores and 34 sidewall cores were recovered. Laboratory tests were made for minerology, consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis of the three tapped zones and measured for water level. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

  4. Geothermal gradients in the Missoula and Bitterroot Valleys, west-central Montana

    USGS Publications Warehouse

    Leonard, Robert B.; Wood, Wayne A.

    1980-01-01

    Temperature-depth profiles of six cased test holes in the Missoula and Bitterroot Valleys, west-central Montana, consist of linear segments, the intersections of which commonly correspond with lithologic boundaries. Geothermal gradients commonly decreased with depth, probably as a result of compaction and higher quartz content of the deeper sedimentary deposits. There is no evidence for hydrothermal discharge. A maximum temperature of 31.7 degrees Celsius was measured at a depth of 869 meters. Estimated temperatures at a depth of 1 kilometer at the drill sites ranged from about 34 to 63 degrees Celsius. Temperatures exceeding 90 degrees Celsius probably would not occur at depths less than 1,500 meters. Values of thermal conductivity needed to maintain an assumed regional heat flow of about 2.1 heat flow units along the measured geothermal gradients generally exceeded published values for the rock and soil penetrated by the wells. Laboratory determinations of the thermal conductivity of cores and cuttings would be useful to refine the estimates and to test the conclusion that the measured temperatures are not hotter than normal. (USGS)

  5. In Situ Aerosol Properties Measured over the California Central Valley and the Sierra Nevada Mountain Range

    NASA Astrophysics Data System (ADS)

    Tomlinson, J. M.; Comstock, J. M.; Hubbe, J.; Kluzek, C.; Schmid, B.; Jonsson, H.; Woods, R.

    2011-12-01

    Anthropogenic aerosols are hypothesized to influence the formation of clouds and precipitation amounts within the Sierra Nevada Mountains. This could have a profound effect on the California water supply. To study this phenomena, an Ultra High Sensitivity Aerosol Spectrometer (UHSAS), Passive Cavity Aerosol Spectrometer (PCASP), and Cloud Aerosol Spectrometer (CAS) were operated aboard the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF) Gulfstream-1 aircraft from February 2 to March 6, 2011 during the CalWater field campaign. The combined aerosol size distribution from the three instruments characterizes the size-resolved concentration of the submicron and supermicron aerosol over the California Central Valley and Sierra Nevada Mountain Range. The measured aerosol size distributions from CalWater are compared with the size distributions measured during the DOE Carbonaceous Aerosol and Radiative Effects Study (CARES) in June 2010 to determine the changes in the aerosol size distributions during different seasons, atmospheric river events, and long-range transport events from Asia. These changes are used to estimate the resulting aerosol effect on cloud condensation nuclei concentrations and the potential impact on cloud formation and precipitation.

  6. Movement of Salt and Nitrate in Shallow Groundwater in California's Central Valley - Large Scale Water, Salt, and Nitrate Balance Calculations

    NASA Astrophysics Data System (ADS)

    Dalgish, B. A.; Boyle, D.; Kretsinger Grabert, V. J.

    2013-12-01

    A large-scale analysis of salt and nitrate was performed for the shallow groundwater aquifer of the entire California Central Valley floor (about 20,000 square miles). This analysis combined many different platforms of data in order to complete water and mass balance calculations. Groundwater and surface water quality test data were used in combination with mass loading from a watershed model (the Environmental Protection Agency's Watershed Analysis Risk Management Framework, or WARMF), as well as an integrated hydrologic model that simulates the use and movement of water coupled between the landscape, surface water, and groundwater (the U.S. Geological Survey's Central Valley Hydrologic Model, or CVHM). For this analysis, the Central Valley floor was divided into 22 zones, and the movement of shallow groundwater, surface water, salt, and nitrate was simulated in, out, and between the zones on a quarterly basis for a 20-year simulation period. In this analysis, shallow groundwater is defined by an estimate of the vertical distance water will travel from the water table within 20 years. Fluxes of mass from deep ambient groundwater and ambient surface water quality were estimated from measured concentration data. Quantities of mass were acquired for recharge (from WARMF output) or calculated using concentrations and other water budget components. Flow and volume components were extracted by post-processing CVHM output data. This resulted in a transient water, salt, and nitrate budget for each of the 22 zones. Simulated shallow groundwater concentrations were calculated to investigate water quality trends for the Central Valley. Four zones were identified as areas with the highest concentrations of salt (TDS) in the southwestern portion of the Central Valley; and six zones were identified as areas with the highest nitrate concentrations, mostly in the southeastern portion of the Valley. Additional analyses intended to shift from the large-scale balance calculations to

  7. Hydrology of Alkali Creek and Castle Valley Ridge coal-lease tracts, central Utah, and potential effects of coal mining

    USGS Publications Warehouse

    Seiler, R.L.; Baskin, R.L.

    1988-01-01

    The Alkali Creek coal-lease tract includes about 2,150 acres in the Book Cliffs coal field in central Utah, and the Castle Valley Ridge coal-lease tract includes about 3,360 acres in the Wasatch Plateau coal field, also in central Utah. Both the Alkali Creek and Castle Valley Ridge coal-lease tracts are near areas where coal is currently (1987) mined by underground methods from the Cretaceous Blackhawk Formation. The Alkali Creek and Castle Valley Ridge areas have intermittent streams in which flow after snowmelt runoff is locally sustained into midsummer by springflow. The only perennial stream is South Fork Corner Canyon Creek in the Castle Valley Ridge area. Peak flow in both areas generally is from snowmelt runoff; however, peak flow from thunderstorm runoff in the Alkali Creek area can exceed that from snowmelt runoff. Estimated annual source-area sediment yield was 0.5 acre-ft/sq mi in the Alkali Creek lease tract and it was 0.3 acre-ft/sq mi in the Castle Valley Ridge lease tract. Groundwater in the Alkali Creek area occurs in perched aquifers in the Flagstaff Limestone and in other formations above the coal-bearing Blackhawk Formation. The principal source of recharge to the aquifers is snowmelt on outcrops. Faults may be major conduits and control the movement of groundwater. Groundwater discharges at formation contacts, between zones of differing permeability within a formation, near faults and into mines. Water sampled from 13 springs in the Alkali Creek area contained dissolved solids at concentrations ranging from 273 to 5,210 mg/L. Water sampled from 17 springs in the Castle Valley Ridge area contained dissolved solids at concentrations ranging from 208 to 579 mg/L. The composition of water from a recently abandoned part of an active mine the Wasatch Plateau closely resembles that of water discharging from a nearby mine that has been abandoned for more than 30 years. Mining of the Alkali Creek and Castle Valley Ridge coal-lease tracts likely will

  8. Knickpoint retreat and landscape disequilibrium on the James River from the Piedmont through the Valley and Ridge, central Virginia, USA

    NASA Astrophysics Data System (ADS)

    Hancock, G.; Harbor, D.; Felis, J.

    2003-12-01

    Several lines of evidence indicate landscape disequilibrium in the James River basin in central Virginia. The river longitudinal profile possesses pronounced convexities and apparently migratory knickzones. Along much of its length, it flows in a narrow inner valley incised into a discontinuous, low-relief upland. In the inner Piedmont, the 150 m wide river channel occupies an incised valley that can be as little as 600 m wide and 75 m deep. Broad fluvial terraces are often found capping the high topography directly adjacent to the valleys, and we use these disconnected terraces to reconstruct paleo-river profiles spanning ~200 km in the Piedmont. These high, extensive terraces disappear in the James River Gap through the Blue Ridge, but reappear with less distinction in the carbonate rocks of the Great Valley. The river remains incised within the Great Valley, with prominent knickzones ~60-100 km above the Blue Ridge gap found on both the mainstem and tributaries. We dated terraces in the Piedmont with in-situ 10Be profiles and a depth integration technique. Dates from the highest terrace level at three locations along ~100 km of the river are ~1 m.yr., suggesting rapid river incision rates of ~55 m/m.yr. We also have documented exceptionally high incision rates along a tributary in the Great Valley. This dating suggests disequilibrium erosion was initiated and has persisted here during the late Quaternary. Assuming the incision is accomplished largely by knickpoint retreat, the dates suggest past retreat rates of up to one m/yr in the Piedmont and 250 m/m.yr. between the outer Piedmont and the Great Valley. We have two hypotheses for how this recent incision was triggered: 1) response to flexural-isostatic uplift generated by drainage basin capture and associated denudation and/or 2) the shift to more rapid climate fluctuations in the early Pleistocene. Additionally, we suggest two interpretations for the generation of the extensive high terrace surfaces. They

  9. Middle Pleistocene palaeoenvironments and the late Lower-Middle Palaeolithic of the Hrazdan valley, central Armenia

    NASA Astrophysics Data System (ADS)

    Wilkinson, Keith; Adler, Daniel; Nahapetyan, Samvel; Smith, Victoria; Mark, Darren; Mallol, Carolina; Blockley, Simon; Gasparian, Boris

    2014-05-01

    The palaeogeographic importance of the southern Caucasus in the Pleistocene as a region of population expansion and contraction between Africa, the Levant and Eurasia is well established as a result of recent archaeological works in the Republics of Armenia and Georgia. Not only does the area have a unique Palaeolithic record, but the presence of volcanic layers in association with archaeological sites and off site sequences means that there is the potential for both high precision dating and correlation. The Hrazdan valley, central Armenia is a case in point. Late Lower to late Middle Palaeolithic sites found as a result of systematic survey and then explored in excavations in 2008-2011 are associated with various volcanogenic strata. 40K/40Ar and 40Ar/39Ar dating in the 1970-2000s demonstrates the onset of volcanism in the adjacent Gegham range in the period 700-500ky BP, while recent 40Ar/39Ar dates on the latest lava from the Gutanasar volcano shows the latest effusive eruption to have occurred at c. 200 ky BP. Nine Middle Pleistocene lavas from the intervening period have been mapped in the Hrazdan valley in a 15km-long study area 12km north-east of Yerevan. Several of the basalts seal terrestrial strata, and thereby bury and 'fossilize' earlier landscapes. The most significant of these is sandwiched between basalts dating to 200 and 440ky BP, where a 135m-long exposure contains a palaeosol developing in floodplain alluvium and in situ archaeological material (Nor Geghi 1). Morphological and micromorphological examination of site strata suggest that hominin activity took place during a temperate episode, which 40Ar/39Ar dating of interbedded crypotephra suggests was MIS 9e. However, strata at other locales buried beneath the same 200ky BP basalt suggest that the landscape occupied by these hominids was a mosaic of river channels, floodplains and lakes. The fossilized MIS 9 landscape is not unique as further lacustrine deposits are buried beneath earlier Middle

  10. Sustaining Irrigated Agriculture in Arid Areas: Lessons Learned in the San Joaquin Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The conventional wisdom is that drainage is required to sustain irrigation in arid and semiarid areas. However, disposal of saline drainage water is a problem throughout the world that is challenging the sustainability of irrigated agriculture. The presence of elements besides salt in the drainage w...

  11. Quaternary landscape evolution of tectonically active intermontane basins: the case of the Middle Aterno River Valley (Abruzzo, Central Italy)

    NASA Astrophysics Data System (ADS)

    Falcucci, Emanuela; Gori, Stefano; Della Seta, Marta; Fubelli, Giandomenico; Fredi, Paola

    2014-05-01

    The Middle Aterno River Valley is characterised by different Quaternary tectonic depressions localised along the present course of the Aterno River (Central Apennine) .This valley includes the L'Aquila and Paganica-Castelnuovo-San Demetrio tectonic basins, to the North, the Middle Aterno Valley and the Subequana tectonic basin, to the South. The aim of this contribution is to improve the knowledge about the Quaternary geomorphological and tectonic evolution of this portion of the Apennine chain. A synchronous lacustrine depositional phase is recognized in all these basins and attributed to the Early Pleistocene by Falcucci et al. (2012). At that time, this sector of the chain showed four distinct closed basins, hydrologically separated from each other and from the Sulmona depression. This depression, actually a tectonic basin too, was localized South of the Middle Aterno River Valley and it was drained by an endorheic hydrographic network. The formation of these basins was due to the activity of different fault systems, namely the Upper Aterno River Valley-Paganica system and San Pio delle Camere fault, to the North, and the Middle Aterno River Valley-Subequana Valley fault system to the South. These tectonic structures were responsible for the origin of local depocentres inside the depressions which hosted the lacustrine basins. Ongoing surveys in the uppermost sectors of the Middle Aterno River Valley revealed the presence of sub-horizontal erosional surfaces that are carved onto the carbonate bedrock and suspended several hundreds of metres over the present thalweg. Gently dipping slope breccias referred to the Early Pleistocene rest on these surfaces, thus suggesting the presence of an ancient low-gradient landscape adjusting to the local base level.. Subsequently, this ancient low relief landscape underwent a strong erosional phase during the Middle Pleistocene. This erosional phase is testified by the occurrence of valley entrenchment and of coeval fluvial

  12. Multi-temporal analysis of an agricultural landscape transformation and abandonment (Lubietová, Central Slovakia)

    NASA Astrophysics Data System (ADS)

    Masný, Matej; Zaušková, Lubica

    2015-12-01

    Socio-political changes in the countries of Eastern and Central Europe in the era of socialism had significant effects on agricultural landscape. Collectivisation (1950 - 1970) lost almost all of traditional agricultural landscapes. On the other hand, the phenomenon of agricultural abandonment started to be significant after 1989. In the model area (part of The Polana Biosphere Reserve) these two processes that formed the agricultural landscape structure were analysed. The analyses were carried out using orthophotos that represented the landscape structure in 1949, 1986 and 2006. It was found that almost complete extinction of the traditional agricultural landscape represented by a mosaic of narrow fields and permanent grasslands occurred during the period. At the same time, increasing trend of abandonment processes was observed. In 2006, non-forestwoody vegetation covered 48% of agricultural land.Natural reforestation as the final stage of agricultural abandonment extended to 46% on the former agricultural land in 2006. Abandonment processes were the most significant already in the period of socialist agriculture. To describe the changes, landscape metrics such as Number of patches (NP), Mean patch size (MPS), Patch size standard deviation (PSSD) and Mean shape index (MSI) were used.

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

    USGS Publications Warehouse

    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

  14. Large-scale single incised valley from a small catchment basin on the western Adriatic margin (central Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Maselli, Vittorio; Trincardi, Fabio

    2013-01-01

    The Manfredonia Incised Valley (MIV) is a huge erosional feature buried below the Apulian shelf, on the western side of the Adriatic margin. The incision extends more than 60 km eastward, from the Tavoliere Plain to the outer shelf, not reaching the shelf edge. High-resolution chirp sonar profiles allow reconstruction of the morphology of the incision and its correlation at regional scale. The MIV records a single episode of incision, induced by the last glacial-interglacial sea level fall that forced the rivers draining the Tavoliere Plain to advance basinward, reaching their maximum extent at the peak of the Last Glacial Maximum. The valley was filled during a relatively short interval of about 10,000 yr during the Late Pleistocene-Holocene sea level rise and almost leveled-off at the time of maximum marine ingression, possibly recording the short-term climatic fluctuations that occurred. The accommodation space generated by the lowstand incision was exploited during the following interval of sea level rise by very high rates of sediment supply that allowed the preservation of up to 45 m of valley fill. High-resolution chirp sonar profiles highlight stratal geometries that are consistent with a typical transgressive valley fill of an estuary environment, including bay-head deltas, central basin and distal barrier-island deposits, organized in a backstepping configuration. The highest complexity of the valley fill is reached in the shallowest and most proximal area, where a kilometric prograding wedge formed during a period dominated by riverine input, possibly connected to high precipitation rates. Based on the depth of the valley margins during this interval, the fill was likely isochronous with the formation of sapropel S1 in the Mediterranean region and may have recorded significant fluctuations within the hydrological cycle.

  15. Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, California

    USGS Publications Warehouse

    May, J.T.; Brown, L.R.

    2002-01-01

    The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, California between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the current study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of California as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the current study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the current study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, California. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic ecosystems; preservation of these ecosystems will require innovative management strategies.

  16. Validation and future predictions based on a new Non-Point Source Assessment Toolbox, applied to the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2011-12-01

    GIS platform and can be used for efficient scenario evaluations without the need to repeat groundwater model simulations. This method is applied to the southern third part of the Central Valley Aquifer, California, which is an intensively farmed semi-arid area, where the local communities rely heavily on groundwater. To obtain a detailed velocity field, the Central Valley Hydrologic Model (CVHM) developed by the USGS was used as the coarse solution, split and refined into a large number of sub-domains. The CVHM resolution is 1 sq mi, with the stresses applied to the center of each cell. In our refined model the well stresses are spatially distributed to a large number of hypothetical wells, where the pumping rates, well depths and screen lengths are obtained from empirical probability distributions, derived from real data. The NPSAT generates a time-dependent water quality probability distribution, which express the time-dependent probability for a discharge surface (e.g., well) to exceed a threshold level of contamination across at a specific time. The model result is compared against real historic nitrate data, and used for future predictions with different scenario evaluations.

  17. Agricultural pesticide exposure and perinatal mortality in central Sudan.

    PubMed Central

    Taha, T. E.; Gray, R. H.

    1993-01-01

    Hospital- and community-based studies were conducted in central Sudan to investigate the association between pesticide exposure and perinatal mortality. The cases were 197 stillbirths in the hospital and 36 perinatal deaths in the community; the controls were 812 liveborn, normal-birth-weight infants in the hospital, and 1505 liveborn infants who survived for the first 7 days after birth in the community. The odds ratio (OR) of perinatal death associated with pesticide exposure was estimated using multiple logistic regression. There was a consistent and significant association between pesticide exposure and perinatal mortality in the hospital (adjusted OR = 1.9; 95% confidence interval (CI): 1.3-2.8) and the community populations (adjusted OR = 2.7; 95% CI: 1.1-6.4). The OR was significantly higher among women engaged in farming (3.6; 95% CI: 1.6-8.0), but not among women in nonfarming occupations (1.6; 95% CI: 0.8-3.3). The estimated attributable risks of perinatal death owing to pesticide exposure were 22.6% for hospital stillbirths and 15.7% for community perinatal deaths; but among women engaged in farming in the hospital population the attributable risks were substantially higher (34.5%). PMID:8324850

  18. Bayesian nitrate source apportionment to individual groundwater wells in the Central Valley by use of elemental and isotopic tracers

    USGS Publications Warehouse

    Ransom, Katherine M; Grote, Mark N.; Deinhart, Amanda; Eppich, Gary; Kendall, Carol; Sanborn, Matthew E.; Sounders, A. Kate; Wimpenny, Joshua; Yin, Qing-zhu; Young, Megan B.; Harter, Thomas

    2016-01-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Shallow domestic wells (less than 150 m deep) in agricultural areas are often contaminated by nitrate. Agricultural and rural nitrate sources include dairy manure, synthetic fertilizers, and septic waste. Knowledge of the relative proportion that each of these sources contributes to nitrate concentration in individual wells can aid future regulatory and land management decisions. We show that nitrogen and oxygen isotopes of nitrate, boron isotopes, and iodine concentrations are a useful, novel combination of groundwater tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate. Furthermore, in this work, we develop a new Bayesian mixing model in which these isotopic and elemental tracers were used to estimate the probability distribution of the fractional contributions of manure, fertilizers, septic waste, and natural sources to the nitrate concentration found in an individual well. The approach was applied to 56 nitrate-impacted private domestic wells located in the San Joaquin Valley. Model analysis found that some domestic wells were clearly dominated by the manure source and suggests evidence for majority contributions from either the septic or fertilizer source for other wells. But, predictions of fractional contributions for septic and fertilizer sources were often of similar magnitude, perhaps because modeled uncertainty about the fraction of each was large. For validation of the Bayesian model, fractional estimates were compared to surrounding land use and estimated source contributions were broadly consistent with nearby land use types.

  19. Bayesian nitrate source apportionment to individual groundwater wells in the Central Valley by use of elemental and isotopic tracers

    NASA Astrophysics Data System (ADS)

    Ransom, Katherine M.; Grote, Mark N.; Deinhart, Amanda; Eppich, Gary; Kendall, Carol; Sanborn, Matthew E.; Souders, A. Kate; Wimpenny, Joshua; Yin, Qing-zhu; Young, Megan; Harter, Thomas

    2016-07-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Shallow domestic wells (less than 150 m deep) in agricultural areas are often contaminated by nitrate. Agricultural and rural nitrate sources include dairy manure, synthetic fertilizers, and septic waste. Knowledge of the relative proportion that each of these sources contributes to nitrate concentration in individual wells can aid future regulatory and land management decisions. We show that nitrogen and oxygen isotopes of nitrate, boron isotopes, and iodine concentrations are a useful, novel combination of groundwater tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate. Furthermore, in this work, we develop a new Bayesian mixing model in which these isotopic and elemental tracers were used to estimate the probability distribution of the fractional contributions of manure, fertilizers, septic waste, and natural sources to the nitrate concentration found in an individual well. The approach was applied to 56 nitrate-impacted private domestic wells located in the San Joaquin Valley. Model analysis found that some domestic wells were clearly dominated by the manure source and suggests evidence for majority contributions from either the septic or fertilizer source for other wells. But, predictions of fractional contributions for septic and fertilizer sources were often of similar magnitude, perhaps because modeled uncertainty about the fraction of each was large. For validation of the Bayesian model, fractional estimates were compared to surrounding land use and estimated source contributions were broadly consistent with nearby land use types.

  20. A site effect study in the Verchiano valley during the 1997 Umbria-Marche (Central Italy) earthquakes

    NASA Astrophysics Data System (ADS)

    Gaffet, Stephane; Cultrera, Giovanna; Dietrich, Michel; Courboulex, Francoise; Marra, Fabrizio; Bouchon, Michel; Caserta, Arrigo; Cornou, Cecile; Deschamps, Anne; Glot, Jean-Paul; Guiguet, Robert

    Strong site effects were observed during the two M W 5.7 and M W 6.0 main shocks of the Colfiorito seismic crisis which occured on September 26, 1997 in Umbria-Marche (Central Italy).The most obvious indications of these effects are the dramatic differences in damage shown by buildings of similar construction in neighboring villages.Such observations were specifically made in the Verchiano valley in the fault area, 15 km south of Colfiorito where the Verchiano village and the Colle and Camino hamlets were heavily damaged (MCS intensity IX-X) since the first main shock of 1997/09/26,while in contrast, the Curasci village located 2 km eastwards remains almost intact.In order to study the anomalous ground motion amplifications in this area, an array of 11, 3-components seismo- and accelero-meters was set up during the 1997/10/20-24 period, extending from the western side of the valley, up to the top of Mount San Salvatore, going accross the Colle and Curasci hamlets.During the experiment, 67 aftershocks enlightened the valley from the Colfiorito (10 km north) and the Sellano (6 km south) active swarms.Seismic refraction experiments were conducted at the same time in the 500 m wide, 1500 m long Verchiano valley in order to determine the thickness and main characteristics of the alluvial infilling.The main results are: (i) compared to the valley side ground motion, and for all the events, recordings in the central part of the valley (piana di Verchiano) show relative amplification of 10 with a clear lengthening of the seismogram duration by a factor of 2 - (ii) broad band relative amplification of 6-8 is also clearly identified at the top of the Mount San Salvatore overhanging the valley - (iii) any of the site effect measurements done explains by itself the strongly contrasted damage observed at Colle and Curasci: i.e. the modification of the near-field radiation pattern by interaction with the free heterogeneous surface may have induced local shadow zones that saved

  1. Floods of November-December 1950 in the Central Valley basin, California

    USGS Publications Warehouse

    Paulsen, C.G.

    1953-01-01

    The flood of November-December 1950 in the Central Valley basin was the greatest in most parts of the basin since the turn of the century and probably was exceeded in the lower San Joaquin River basin only by the historic flood of 1862. In respect to monetary loss, the 1950 flood was the most disastrous in the history of the basin. Loss of life was remarkably small when one considers the extensive damage and destruction to homes and other property, which is estimated at 33 million dollars. Outstanding features of the flood were its unprecedented occurrence so early in the winter flood season, its magnitude in respect to both peak and volume in most major tributaries, and the occurrence of a succession of near-peak flows with a period of three weeks. The flood was caused by a series of storms during the period November 16 to December 8, which brought exceptionally warm, moisture-laden air inland against the Sierra Nevada range and caused intense rainfall, instead of snowfall, at unusually high altitudes. Basin-wide totals of rainfall during the period ranged from 30 inches over the Yuba and American River basins to 13 inches over the upper Sacramento and Feather River basins. Based on continuous records of discharge on major tributaries for periods ranging from 22 to 55 years and averaging about 43 years, the 1950 flood peaks were the greatest of record on the American, Cosumnes, Mokelumne, Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, lower San Joaquin, Kings, Kaweah, Tule, and Kern Rivers. Second highest peak of record occurred during the flood of March 1928 on the Yuba, American and Mokelumne Rivers; the flood of Marcn 1940 on Cosumnes River; the flood of January 1911 on the Stanislaus and Tuolumne Rivers; the flood of December 1937 on the Merced, Kings, and Kaweah Rivers; the flood of March 1938 on the Chowchilla, Fresno, and lower San Joaquin Rivers; and the flood of March 1943 on the Tule and Kern Rivers. Peak discharges for 1950 did not exceed previous

  2. Serosurveillance of infectious agents in equines of the Central Valley of Costa Rica.

    PubMed

    Jiménez, D; Romero-Zuñiga, J J; Dolz, G

    2014-01-01

    Blood samples from 181 equines from the Central Valley of Costa Rica were collected in the year 2012 to determine the presence of antibodies against selected infectious agents in horses and to determine the risk factors associated with these agents. The presence of antibodies against Equine Infectious Anemia Virus (EIAV), Equine Herpes Virus 1 and 4 (EHV-1 and EHV-4), West Nile Virus (WNV), Influenza A Virus (IAV), Equine Viral Arteritis Virus (EVAV), Babesia caballi, Theileria equi, Neospora caninum and Chlamydia abortus was determined using commercial assays, and risk factors associated with seropositivity to the different infectious agents was established. The most seroprevalent agent detected was EHV-4 (96.7%), followed by WNV (44.2%), and IAV (41.8%). Horses >3 years, used for work or sports, and with access to pastures, had significantly increased probability to be seropositive to WNV, whereas horses used for breeding and recreational purposes, being stabled, and without access to pastures, had significantly greater probability to be seropositive to IAV. Seroprevalence to B. caballi (19.9%) was lower than to T. equi (38.1%). For B. caballi, access to pastures was determined as a risk factor, whereas being older than 3 years was established as a risk factor for T. equi. Low seroprevalences were determined for EHV-1 (5.0%), EVAV (5.0%), C. abortus (4.8%), and N. caninum (4.4%). Mares having history of abortion were more likely to be seropositive to EHV-1, whereas horses >3 years, used for work and sports, and mares having multiple parturitions, were more likely to be seropositive to N. caninum. None of the horses were seropositive to EIAV. Earlier, only diseases caused by EIAV, WNV and piroplasmosis were reported in Costa Rica. The present study however, determined the presence of carriers for EHV-1, EHV-4, and EIAV.

  3. Rainwater harvesting for small-scale irrigation of maize in the Central Rift Valley, Ethiopia

    NASA Astrophysics Data System (ADS)

    Keesstra, Saskia; Hartog, Maaike; Muluneh, Alemayehu; Stroosnijder, Leo

    2013-04-01

    In the Central Rift Valley of Ethiopia, small scale farmers mostly rely on rainfall for crop production. The erratic nature of rainfall causes frequent crop failures and makes the region structurally dependent on food aid. Rainwater Harvesting (RWH) is a technique to collect and store runoff that could provide water for livestock, domestic use or small scale irrigation. Usually, such irrigation is promoted for high value crops, but in the light of regional food security it may become interesting to invest in irrigation of maize. In this research, two cemented RWH cisterns were investigated to determine their economic and social potential for supplemental irrigation of maize using drip irrigation. For this, data from test fields with irrigated maize and monitoring of water levels of the cisterns were used, as well as a survey under 30 farmers living close to the experimental site. The results show that catchment size and management should be in balance with the designed RWH system, to prevent too little runoff or flooding. An analysis with Cropwat 8.0 was used to investigate the possibility of irrigating maize with the observed amounts of water in the RWH cisterns. This would suffice for 0.3-0.8 ha of maize. For a RWH cistern with a drip irrigation system to be economically viable, the production on this acreage should become 3-4 ton/ha; 2.5 times higher than the current yield. But the biggest challenge would be to change the perception of respondents, who don't find it logical to spend precious water on a common crop like maize. Therefore, if the Ethiopian government considers the irrigation of maize to be important for regional food security, it is recommended to either subsidize the construction of RWH cisterns or provide credit on favourable terms.

  4. Serosurveillance of infectious agents in equines of the Central Valley of Costa Rica

    PubMed Central

    Jiménez, D.; Romero-Zuñiga, J.J.; Dolz, G.

    2014-01-01

    Blood samples from 181 equines from the Central Valley of Costa Rica were collected in the year 2012 to determine the presence of antibodies against selected infectious agents in horses and to determine the risk factors associated with these agents. The presence of antibodies against Equine Infectious Anemia Virus (EIAV), Equine Herpes Virus 1 and 4 (EHV-1 and EHV-4), West Nile Virus (WNV), Influenza A Virus (IAV), Equine Viral Arteritis Virus (EVAV), Babesia caballi, Theileria equi, Neospora caninum and Chlamydia abortus was determined using commercial assays, and risk factors associated with seropositivity to the different infectious agents was established. The most seroprevalent agent detected was EHV-4 (96.7%), followed by WNV (44.2%), and IAV (41.8%). Horses >3 years, used for work or sports, and with access to pastures, had significantly increased probability to be seropositive to WNV, whereas horses used for breeding and recreational purposes, being stabled, and without access to pastures, had significantly greater probability to be seropositive to IAV. Seroprevalence to B. caballi (19.9%) was lower than to T. equi (38.1%). For B. caballi, access to pastures was determined as a risk factor, whereas being older than 3 years was established as a risk factor for T. equi. Low seroprevalences were determined for EHV-1 (5.0%), EVAV (5.0%), C. abortus (4.8%), and N. caninum (4.4%). Mares having history of abortion were more likely to be seropositive to EHV-1, whereas horses >3 years, used for work and sports, and mares having multiple parturitions, were more likely to be seropositive to N. caninum. None of the horses were seropositive to EIAV. Earlier, only diseases caused by EIAV, WNV and piroplasmosis were reported in Costa Rica. The present study however, determined the presence of carriers for EHV-1, EHV-4, and EIAV. PMID:26623349

  5. Agricultural producers' perceptions of sandhill cranes in the San Luis Valley of Colorado

    USGS Publications Warehouse

    Laubhan, M.K.; Gammonley, J.H.

    2001-01-01

    Management for migratory birds at an ecosystem scale requires forming cooperative partnerships with the private sector. To be effective, however, wildlife managers must understand the economic and social attitudes of private landowners to ensure that strategies involving stakeholders are viable and can be implemented. We documented attitudes of farmers in the San Luis Valley (SLV) of Colorado toward Rocky Mountain Population greater sandhill cranes (Grus canadensis tabida) using a self administered, mail-back survey. Overall response rate was 46.7%. Viewing sandhill cranes in the SLV was considered somewhat important or important by 78.6% of respondents. In contrast, only 62.1% of respondents indicated that viewing sandhill cranes was somewhat important or important on their own land. Farmers' attitudes toward viewing sandhill cranes on their own property were related (P=0.02) to perceived conflicts with crop production. The extent of crane use (P=0.04) was the only variable we tested that predicted whether conflicts were reported. Our results suggest that partnerships between farmers and natural resource agencies concerned with management of sandhill cranes may be viable. However, the role of farmers in any proposed management strategy must be examined carefully because there may be an upper limit of crane use on private land that farmers will tolerate.

  6. Physical activity in youth from a subsistence agriculture community in the Valley of Oaxaca, southern Mexico.

    PubMed

    Malina, Robert M; Reyes, Maria Eugenia Peña; Tan, Swee Kheng; Little, Bertis B

    2008-08-01

    Observations of activities of contemporary subsistence agricultural communities may provide insights into the lifestyle of youth of 2 to 3 generations ago. The purpose of this study was to document age- and sex-associated variation in household activities and daily steps walking to school of youth 9-17 years in an indigenous subsistence agricultural community in Oaxaca, southern Mexico. Activities during leisure were also considered. A cross-sectional survey of a rural Zapotec-speaking community was undertaken, and respondents included 118 boys and 152 girls, aged 8.7-17.9 years. Household and leisure activities were documented by questionnaire and subsequent interview. Household activities were classified by estimated intensity for before and after school and on the weekend, and an estimate of METS per day accumulated while doing chores was derived. Number of steps from home to school was estimated. Contingency table analysis and MANCOVA controlling for age was used to evaluate results. Household activities tended to cluster at light and moderate intensities in girls and at moderate to moderate-to-vigorous intensities in boys. Estimated METS per day in approximately 2 h of chores differed significantly by sex. Secondary school girls expended significantly more METS per day in chores than primary school girls, but there was no difference by school level in boys. The daily round trip from home to school was approximately 2400 steps for primary students and approximately 2700 and approximately 3100 steps for secondary boys and girls, respectively. Television viewing and participation in sports were major leisure activities for boys and girls. Daily household chores, walking, and leisure activities suggest moderately active and moderately-to-vigorously active lifestyles in girls and boys, respectively, in this indigenous subsistence agricultural community.

  7. A detailed lithologic study of glacially buried valley in central Champaign County, Ohio

    SciTech Connect

    Schilling, D.J.; Dominic, D.F. . Dept. of Geological Sciences)

    1994-04-01

    Previous subsurface mapping in this area has identified a bedrock valley (Teays), which trends southeast to northwest and has a maximum depth of 135 m and width of 7 km. The valley is largely filled with outwash and is flanked on the east by moraines. This study focuses on the details of the sedimentary fill in the valley; it was spurred by proposed highway construction and its possible effects on a nearby fen. In addition to the surficial geology map of the county, lithologic interpretations were based on logs of water wells, and lithologic logs of 43 wells drilled by Wright State University to evaluate the stratigraphy of the valley, together with 26 gamma logs of these holes. The well logs were interpreted in terms of seven standardized lithologies and then correlated as depositional units on cross sections.

  8. Agricultural Adjustment and the Diversification of Farm Households and Corporate Farms in Central Europe

    ERIC Educational Resources Information Center

    Chaplin, Hannah; Davidova, Sophia; Gorton, Matthew

    2004-01-01

    Survey evidence from three Central European Countries (Czech Republic, Hungary and Poland) is analysed to identify the degree of non-agricultural farm diversification and the factors facilitating or impeding it in individual and corporate farms. The effect of diversification on rural job creation and household incomes is investigated. The results…

  9. Pre-Hispanic agricultural decline prior to the Spanish Conquest in southern Central America

    NASA Astrophysics Data System (ADS)

    Taylor, Zachary P.; Horn, Sally P.; Finkelstein, David B.

    2013-08-01

    Archeological and paleoenvironmental records from southern Central America attribute population collapse to the Spanish Conquest about 500 years ago. Paleoclimate records from the circum-Caribbean have shown evidence of severe, regional droughts that contributed to the collapse of the Mayan Civilization, but there are few records of these droughts in southern Central America and no records of their effects on prehistoric populations in the region. Here we present a high-resolution lake sediment record of prehistoric agricultural activities using bulk sediment stable carbon isotopes from Laguna Zoncho, Costa Rica. We find isotopic evidence that agriculture was nearly absent from the watershed approximately 220 years prior to the Spanish arrival in Costa Rica and identify two distinct periods of agricultural decline, 1150-970 and 860-640 cal yr BP, which correspond to severe droughts in central Mexico. We attribute decreases in agriculture to a weakened Central American monsoon, which would have shortened the growing season at Laguna Zoncho, reduced crop yields, and negatively affected prehistoric populations.

  10. Late Holocene glacial history of the Copper River Delta, coastal south-central Alaska, and controls on valley glacier fluctuations

    NASA Astrophysics Data System (ADS)

    Barclay, David J.; Yager, Elowyn M.; Graves, Jason; Kloczko, Michael; Calkin, Parker E.

    2013-12-01

    Fluctuations of four valley glaciers in coastal south-central Alaska are reconstructed for the past two millennia. Tree-ring crossdates on 216 glacially killed stumps and logs provide the primary age control, and are integrated with glacial stratigraphy, ages of living trees on extant landforms, and historic forefield photographs to constrain former ice margin positions. Sheridan Glacier shows four distinct phases of advance: in the 530s to c.640s in the First Millennium A.D., and the 1240s to 1280s, 1510s to 1700s, and c.1810s to 1860s during the Little Ice Age (LIA). The latter two LIA advances are also recorded on the forefields of nearby Scott, Sherman and Saddlebag glaciers. Comparison of the Sheridan record with other two-millennia long tree-ring constrained valley glacier histories from south-central Alaska and Switzerland shows the same four intervals of advance. These expansions were coeval with decreases in insolation, supporting solar irradiance as the primary pacemaker for centennial-scale fluctuations of mid-latitude valley glaciers prior to the 20th century. Volcanic aerosols, coupled atmospheric-oceanic systems, and local glacier-specific effects may be important to glacier fluctuations as supplemental forcing factors, for causing decadal-scale differences between regions, and as a climatic filter affecting the magnitude of advances.

  11. Late Pleistocene and Holocene environmental history of the Iguala Valley, Central Balsas Watershed of Mexico.

    PubMed

    Piperno, D R; Moreno, J E; Iriarte, J; Holst, I; Lachniet, M; Jones, J G; Ranere, A J; Castanzo, R

    2007-07-17

    The origin of agriculture was a signal development in human affairs and as such has occupied the attention of scholars from the natural and social sciences for well over a century. Historical studies of climate and vegetation are closely associated with crop plant evolution because they can reveal the ecological contexts of plant domestication together with the antiquity and effects of agricultural practices on the environment. In this article, we present paleoecological evidence from three lakes and a swamp located in the Central Balsas watershed of tropical southwestern Mexico that date from 14,000 B.P. to the modern era. [Dates expressed in B.P. years are radiocarbon ages. Calibrated (calendar) ages, expressed as cal B.P., are provided for dates in the text.] Previous molecular studies suggest that maize (Zea mays L.) and other important crops such as squashes (Cucurbita spp.) were domesticated in the region. Our combined pollen, phytolith, charcoal, and sedimentary studies indicate that during the late glacial period (14,000-10,000 B.P.), lake beds were dry, the climate was cooler and drier, and open vegetational communities were more widespread than after the Pleistocene ended. Zea was a continuous part of the vegetation since at least the terminal Pleistocene. During the Holocene, lakes became important foci of human activity, and cultural interference with a species-diverse tropical forest is indicated. Maize and squash were grown at lake edges starting between 10,000 and 5,000 B.P., most likely sometime during the first half of that period. Significant episodes of climatic drying evidenced between 1,800 B.P. and 900 B.P. appear to be coeval with those documented in the Classic Maya region and elsewhere, showing widespread instability in the late Holocene climate.

  12. Late Pleistocene and Holocene environmental history of the Iguala Valley, Central Balsas Watershed of Mexico

    PubMed Central

    Piperno, D. R.; Moreno, J. E.; Iriarte, J.; Holst, I.; Lachniet, M.; Jones, J. G.; Ranere, A. J.; Castanzo, R.

    2007-01-01

    The origin of agriculture was a signal development in human affairs and as such has occupied the attention of scholars from the natural and social sciences for well over a century. Historical studies of climate and vegetation are closely associated with crop plant evolution because they can reveal the ecological contexts of plant domestication together with the antiquity and effects of agricultural practices on the environment. In this article, we present paleoecological evidence from three lakes and a swamp located in the Central Balsas watershed of tropical southwestern Mexico that date from 14,000 B.P. to the modern era. [Dates expressed in B.P. years are radiocarbon ages. Calibrated (calendar) ages, expressed as cal B.P., are provided for dates in the text.] Previous molecular studies suggest that maize (Zea mays L.) and other important crops such as squashes (Cucurbita spp.) were domesticated in the region. Our combined pollen, phytolith, charcoal, and sedimentary studies indicate that during the late glacial period (14,000–10,000 B.P.), lake beds were dry, the climate was cooler and drier, and open vegetational communities were more widespread than after the Pleistocene ended. Zea was a continuous part of the vegetation since at least the terminal Pleistocene. During the Holocene, lakes became important foci of human activity, and cultural interference with a species-diverse tropical forest is indicated. Maize and squash were grown at lake edges starting between 10,000 and 5,000 B.P., most likely sometime during the first half of that period. Significant episodes of climatic drying evidenced between 1,800 B.P. and 900 B.P. appear to be coeval with those documented in the Classic Maya region and elsewhere, showing widespread instability in the late Holocene climate. PMID:17537917

  13. Nitrogen loadings and environmental impacts in rice agriculture catchments in subtropical central China

    NASA Astrophysics Data System (ADS)

    Wang, Y.

    2015-12-01

    The severe deterioration of water quality in rice agriculture catchments challenges ecologists and hydrologists in exploring how rice agriculture affects nutrient loadings and water quality. This research observed the nitrogen (N) concentrations in stream water and groundwater in one forest and five rice agriculture catchments in subtropical central China to quantify the relationships between rice agriculture intensification, water quality of water bodies, and catchment N loadings. Our results indicate that intensive rice agriculture deteriorated stream water quality. A non-linear fitting analysis using a Boltzmann sigmoid function suggests that the concentrations and mass fluxes of ammonium-N (NH4+-N), nitrate-N (NO3--N), and total N (TN) in stream water increase with the areal proportion of rice agriculture in the catchments; however, these increases can only be detected when the areal proportions of rice agriculture in the catchments are greater than 13-30%, highlighting the importance of reasonable land use planning for managing stream water quality as well as N loadings from catchments. The factorial correspondence analysis (FCA) also suggests that rice agriculture has a potential to impose groundwater NH4+-N pollution, particularly in the soil exhausting season of July - October. And, the great N fertilizer application rates for rice cropping can increase the groundwater NO3-N and TN concentrations due to large quantities of N leaching into groundwater system beneath the paddy fields. The high N concentrations in groundwater result in strong N loadings via the base flow process. The NO3--N loadings via the base flow reaches 0.12-0.27 kg N ha-1 month-1 in the rice agriculture catchments, contributing 27.3%-36.5% of the total NO3--N loadings by the stream discharge. Therefore, the best management practices for N reduction and the smart land use planning should be applied in the rice agriculture catchments to improve water quality and mitigate N loadings.

  14. Prevalence of hepatitis B infection among young and unsuspecting Hmong blood donors in the Central California Valley.

    PubMed

    Sheikh, Muhammad Y; Atla, Pradeep R; Raoufi, Rahim; Sadiq, Humaira; Sadler, Patrick C

    2012-02-01

    Chronic hepatitis B virus (HBV) infection may result in cirrhosis and/or hepatocellular carcinoma and is one of the leading causes of mortality in Asian Americans including Hmong Americans. The Central California Valley is home to a huge Hmong population. To date, the true prevalence of HBV among Hmong is largely unknown. The aim of this study was to contribute to the limited data on HBV prevalence and its trends in Hmong population in the Central California Valley. Between fiscal years 2006 and 2010, a total of 219, 450 voluntary donors were identified at Central California Blood Center in Fresno. Of these, 821 (399 males and 422 females) were Hmong donors. A cross-sectional review of the HBV (hepatitis B surface antigen) positivity among all donors was carried out. Prevalence estimates with 95% confidence intervals (CI) were calculated. Ninety-two percent of Hmong donors were between age groups 16 and 35 years, and only 8% were ≥36 years. The overall prevalence in Hmong was noted at 3.41% (95%CI 2.3-4.9) compared to 0.06% (95%CI 0.05-0.07) in donors of all ethnicities. The calculated prevalence could be an underestimate of the true HBV prevalence in Hmong as the study enrolled only healthy blood donors with predominant younger age (≤35 years) population. These results underscore the persistent burden of HBV infection and potentially increased risk of premature death even in the second generation Hmong community of the Central California Valley. This study reemphasizes the unequivocal need to develop robust preventive and treatment strategies for HBV in Hmong community.

  15. Hydrochemistry of the Mahomet Bedrock Valley Aquifer, East-Central Illinois: indicators of recharge and ground-water flow

    USGS Publications Warehouse

    Panno, S.V.; Hackley, Keith C.; Cartwright, K.; Liu, Chao-Li

    1994-01-01

    A conceptual model of the ground-water flow and recharge to the Mahomet Bedrock Valley Aquifer (MVA), east-central Illinois, was developed using major ion chemistry and isotope geochemistry. The MVA is a 'basal' fill in the east-west trending buried bedrock valley composed of clean, permeable sand and gravel to thicknesses of up to 61 m. It is covered by a thick sequence of glacial till containing thinner bodies of interbedded sand and gravel. Ground water from the MVA was found to be characterized by clearly defined geochemical regions with three distinct ground-water types. A fourth ground-water type was found at the confluence of the MVA and the Mackinaw Bedrock Valley Aquifer (MAK) to the west. Ground water in the Onarga Valley, a northeastern tributary of the MVA, is of two types, a mixed cation-SO42- type and a mixed cation-HCO3- type. The ground water is enriched in Na+, Ca2+, Mg2+, and SO42- which appears to be the result of an upward hydraulic gradient and interaction of deeper ground water with oxidized pyritic coals and shale. We suggest that recharge to the Onarga Valley and overlying aquifers is 100% from bedrock (leakage) and lateral flow from the MVA to the south. The central MVA (south of the Onarga Valley) is composed of relatively dilute ground water of a mixed cation-HCO3- type, with low total dissolved solids, and very low concentrations of Cl- and SO42-. Stratigraphic relationships of overlying aquifers and ground-water chemistry of these and the MVA suggest recharge to this region of the MVA (predominantly in Champaign County) is relatively rapid and primarily from the surface. Midway along the westerly flow path of the MVA (western MVA), ground water is a mixed cation-HCO3- type with relatively high Cl-, where Cl- increases abruptly by one to ??? two orders of magnitude. Data suggest that the increase in Cl- is the result of leakage of saline ground water from bedrock into the MVA. Mass-balance calculations indicate that approximately 9.5% of

  16. Landscape context mediates influence of local food abundance on wetland use by wintering shorebirds in an agricultural valley

    USGS Publications Warehouse

    Taft, Oriane W.; Haig, Susan M.

    2006-01-01

    While it is widely understood that local abundance of benthic invertebrates can greatly influence the distribution and abundance of wetland birds, no studies have examined if wetland landscape context can mediate this relationship. We studied the influence of wetland food abundance and landscape context on use of agricultural wetlands by wintering dunlin (Calidris alpina) and killdeer (Charadrius vociferus) in the Willamette Valley of Oregon, USA, over two winters (1999a??2000, 2000a??2001) of differing rainfall and subsequent habitat distribution. We monitored bird use (frequency of occurrence and abundance) at a sample of wetlands differing in local food abundance (density and biomass) and landscape context [adjacent shorebird habitat (defined as ha of wet habitat with less than 50% vegetative cover and within a 2-km radius) and nearest neighbor distance]. We evaluated predictive models for bird use using linear regression and the Cp criterion to select the most parsimonious model. During the dry winter (2000a??2001), dunlin exhibited greater use of sites with higher invertebrate density and biomass but also with more adjacent shorebird habitat and closest to a wetland neighbor. However, neither landscape context nor food abundance were important predictors of dunlin use during the wet winter (1999a??2000). Use of sites by killdeer was unrelated to either local food abundance or landscape context measures during both winters. Our findings contribute to a growing recognition of the importance of landscape structure to wetland birds and highlight a number of implications for the spatial planning and enhancement of wetlands using a landscape approach.

  17. Processes affecting the distribution of selenium in shallow groundwater of agricultural areas, western San Joaquin Valley, California

    USGS Publications Warehouse

    Deverel, S.J.; Fujii, R.

    1988-01-01

    A study was undertaken to evaluate the processes affecting the chemistry of shallow groundwater associated with agricultural drainage systems in the western San Joaquin Valley, California. The study was prompted by a need for an understanding of selenium mobility in areas having high selenium concentrations in shallow groundwater. Groundwater samples were collected along transects in three artificially drained fields where the age of the drainage system varied (15, 6, and 1.5 years). Selenium concentrations in the drain water also varied (430, 58, and 3700 μg/L, respectively). Isotopic enrichment and chemical composition of the groundwater samples indicate that saline- and selenium-enriched water has evolved as a result of evaporation or transpiration of groundwater. This evaporated, isotopically enriched water is being displaced by more recent, less saline irrigation water percolating through the root zone. This displacement seems to be a process whereby sodium chloride and sodium sulfate water is being replaced by more dilute calcium sulfate and calcium bicarbonate water.

  18. Processes affecting the distribution of selenium in shallow ground water of agricultural areas, western San Joaquin Valley, California

    USGS Publications Warehouse

    Deverel, S.J.; Fujii, Roger

    1987-01-01

    A study was undertaken to evaluate the processes affecting the chemistry of shallow groundwater associated with agricultural drainage systems in the western San Joaquin Valley, California. The study was prompted by a need for an understanding of selenium mobility in areas having high selenium concentrations in shallow groundwater. Groundwater samples were collected along transects in three artificially drained fields where the age of the drainage system varied (15, 6, and 1.5 years). Selenium concentrations in the drainage water also varied (430, 58, and 3700 mg/L, respectively). Isotopic enrichment and chemical composition of the groundwater samples indicate that saline- and selenium- enriched water has evolved as a result of evaporation of groundwater. This evaporated, isotopically enriched water is being displaced by more recent, less saline irrigation water percolating through the root zone. This placement seems to be a process in which sodium chloride and sodium sulfate water is being replaced by more dilute calcium sulfate and calcium bicarbonate water. (Author 's abstract)

  19. Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Moss, R. C.; Blumenshine, S.; Fleskes, J.

    2005-05-01

    California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km2 region, increase aquatic insect production and aid in the recovery of declining bird populations.

  20. Regional hydrogeochemical groundwater characterization and Natural Arsenic occurrence in Upper Valtellina Valley (Central Italian Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Pena Reyes, Fredy; Crosta, Giovanni B.; Frattini, Paolo; Basiricò, Stefano

    2015-04-01

    The aim of the research is the characterization of the alpine Upper Valtellina Valley (central Italian Alps, 800 km2) aquifers by means of hydrogeological, hydrogeochemical, As speciation, isotopic and whole-rock analyses. In particular, the main focus of the study was the understanding of the processes responsible for As release and mobilization into the groundwater. Historical chemical data from springs, wells, lakes, rivers and public fountains were collected from the Lombardy Region Health Agency (ASL) and implemented into a geodatabase. The available groundwater chemistry analyses (3050) from five municipalities (Bormio, Livigno, Valdidentro, Valdisotto and Valfurva) cover a relatively long time span between 1996 and 2011. Moreover, samples across the entire study area and covering one full hydrologic year 2012-2013 were collected during four different campaigns (June 2012, October 2012, May 2013, and September 2013) and analyzed . During these campaigns, water samples have been collected from both cold springs and thermal springs. The hydrogeochemistry of aquifers and superficial waters through the hydrologic year, and the long-term regional As distribution and time variability were analyzed. Although the studied springs belong to different catchments with different hydrochemical and lithological conditions, they present some typical characteristics: (1) the water types are dominated by dissolution of the main ions Ca - Mg and SO4-HCO3; (2) the Cl concentration is always very low, and poorly correlated with other ions; (3) the circulation time obtained from isotopic data ranges between 5 and 10 years for thermal springs and it is lower than 2 years for cold springs; (4) the average yearly temperatures (about 12°C for cold springs, and between 18°C and 42° for thermal springs) are nearly constant through the year; (5) dominant oxidizing environments have been observed for most of the cold springs and also for the thermal springs; (6) anthropogenic

  1. Bridging dry spells for maize cropping through supplemental irrigation in the Central Rift Valley of Ethiopia

    NASA Astrophysics Data System (ADS)

    Muluneh Bitew, Alemayehu; Keesstra, Saskia; Stroosnijder, Leo

    2015-04-01

    Maize yield in the Central Rift Valley of Ethiopia (CRV) suffers from dry spells at sensitive growth stages. Risk of crop failure makes farmers reluctant to invest in fertilizer. This makes the CRV food insecure. There are farms with well-maintained terraces and Rain Water Harvesting (RWH) systems using concrete farms ponds. We tested the hypothesis that in these farms supplemental irrigation with simultaneous crop intensification might boost production of a small maize area sufficient to improve food security. Intensification includes a higher plant density of a hybrid variety under optimum fertilization. First we assessed the probability of occurrence of dry spells. Then we estimated the availability of sufficient runoff in the ponds in dry years. During 2012 (dry) and 2013 (wet) on-farm field research was conducted with 10 combinations of supplemental irrigation and plant density. The simplest was rainfed farming with 30,000 plants ha-1. The most advanced was no water stress and 75,000 plants ha-1. Finally we compared our on-farm yield with that of neighbouring farmers. Because 2013 was a wet year no irrigation was needed. Our long term daily rainfall (1970-2011) analysis proves the occurrence of dry spells during the onset of the maize (Belg months March and April). In March there is hardly enough water in the ponds. So, we advise later sowing. Starting from April available water (runoff from a 2.2 ha catchment) matches crop water requirement (for 0.5 ha maize). Significant differences between grain and total biomass yield were observed between rainfed and other irrigation levels. However, since the largest difference is only 12%, the investment in irrigation non-critical drought years is not worth the effort. There was also a limited effect (18-22%) of increasing plant density. So, we advise not to use more than 45,000 plants ha-1. The grain yield and total biomass difference between farmers own practice and our on-farm research was 101% and 84% respectively

  2. Historical estimates of spatial reference evapotranspiration for the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Falk, M.; Snyder, R. L.; Orang, M.; Hayes, S.

    2009-12-01

    In this study we present spatial reference evapotranspiration (ETo) estimates for the Central Valley from 1921 to 2008 derived from NCDC/NOAA daily climate data and PRISM monthly climate data grids (PRISM group; Oregon State University, Corvallis, USA; http://www.prism.oregonstate.edu). Data from the California Irrigation Management Information System (CIMIS) weather station were also used. 2009 is currently the third year of drought in California and better tools for irrigation and water resource management are needed to provide a secure water supply in the future. Temperature and Precipitation are driving variables in the estimation of ET occurring on the landscape scale. Consequently, modeling evaluations of a growing number of hydrological issues are increasingly requiring reliable area coverage of meteorological datasets. The availability of these datasets with adequate spatial and temporal resolution is particularly critical for decision support models for better management of water resources, such as the SIMETAW-II project supported with this study. Daily maximum-minimum temperature and precipitation spatial datasets were calculated by combining daily NCDC climate station data and monthly PRISM climate data grids. This study relies on the input PRISM grids to reproduce spatial climate patterns as well as anchor the daily climate values to the monthly averages given in the PRISM dataset such as total monthly precipitation and average daily temperatures. The historic daily climate data available for the period from 1921 to present consists of data for minimum temperature, maximum temperature and precipitation. Due to this restricted historical data set we cannot directly compute Penman-Monteith Reference Evapotranspiration (ETo) as adopted by the Environmental Water Resources Institute - American Society of Civil Engineers (ASCE-EWRI, 2004). Instead this study uses the Hargreaves-Samani equation for estimating Reference Evapotranspiration (ETh). For the final

  3. InSAR data produce specific storage estimates for an agricultural area in the San Luis Valley, Colorado

    NASA Astrophysics Data System (ADS)

    Reeves, J.; Knight, R. J.; Zebker, H. A.; Schreuder, W.; Agram, P. S.; Lauknes, T.

    2010-12-01

    The San Luis Valley (SLV) is an 8000 km2 region in southern Colorado that is home to a thriving agricultural economy. This valley is currently in a period of extreme drought, with county and state regulators struggling to develop appropriate management policies in order to sustain water levels in the confined aquifer system. The water level from 1970 - 2000 remains a key, but poorly known, component for characterization. Some relevant data, such as water levels measured in wells, were collected during this period and incorporated into a groundwater flow model. However, data with finer spatial and temporal resolution would be very valuable in understanding the behavior and therefore the management of the system. Spaceborne interferometric synthetic aperture radar (InSAR) data provide maps of the deformation of the Earth’s surface at a spatial resolution of 50 m; these data are acquired approximately once per month. The deformation measured by InSAR can be related to water levels in the confined aquifer system. However, changes in cm-scale crop structure in agricultural areas lead to signal decorrelation over long periods of time, resulting in low quality data. Here we apply the recently developed small baseline subset (SBAS) analysis to InSAR data collected by the European Space Agency’s ERS-1 and ERS-2 satellites over the western SLV for the years 1992-2001. The SBAS measurements show high levels of InSAR correlation, denoting high quality data, in areas between the center pivot irrigation circles, where the lack of water results in little surface vegetation. By using SBAS analysis, we are able to estimate the magnitude of the seasonal deformation and compare it with hydraulic head measurements in nearby wells. We directly compare, at three well locations, specific storage parameters estimated from InSAR data to those estimated using traditional pump test techniques. The InSAR and pump test estimated parameters are: 3.4 x10-5 ft-1 vs. 1.7 x 10-5 ft-1, 2.2 x 10

  4. Assessing Drought Impacts on Water Storage using GRACE Satellites and Regional Groundwater Modeling in the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Scanlon, B. R.; Zhang, Z.; Save, H.; Faunt, C. C.; Dettinger, M. D.

    2015-12-01

    Increasing concerns about drought impacts on water resources in California underscores the need to better understand effects of drought on water storage and coping strategies. Here we use a new GRACE mascons solution with high spatial resolution (1 degree) developed at the Univ. of Texas Center for Space Research (CSR) and output from the most recent regional groundwater model developed by the U.S. Geological Survey to evaluate changes in water storage in response to recent droughts. We also extend the analysis of drought impacts on water storage back to the 1980s using modeling and monitoring data. The drought has been intensifying since 2012 with almost 50% of the state and 100% of the Central Valley under exceptional drought in 2015. Total water storage from GRACE data declined sharply during the current drought, similar to the rate of depletion during the previous drought in 2007 - 2009. However, only 45% average recovery between the two droughts results in a much greater cumulative impact of both droughts. The CSR GRACE Mascons data offer unprecedented spatial resolution with no leakage to the oceans and no requirement for signal restoration. Snow and reservoir storage declines contribute to the total water storage depletion estimated by GRACE with the residuals attributed to groundwater storage. Rates of groundwater storage depletion are consistent with the results of regional groundwater modeling in the Central Valley. Traditional approaches to coping with these climate extremes has focused on surface water reservoir storage; however, increasing conjunctive use of surface water and groundwater and storing excess water from wet periods in depleted aquifers is increasing in the Central Valley.

  5. Assessing the Vulnerability of Public-Supply Wells to Contamination: Central Valley Aquifer System near Modesto, California

    USGS Publications Warehouse

    Jagucki, Martha L.; Jurgens, Bryant C.; Burow, Karen R.; Eberts, Sandra M.

    2009-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well in Modesto, California. The well selected for study pumps on average about 1,600 gallons per minute from the Central Valley aquifer system during peak summer demand. Water samples were collected at the public-supply well and at monitoring wells installed in the Modesto vicinity. Samples from the public-supply wellhead contained the undesirable constituents uranium, nitrate, arsenic, volatile organic compounds (VOCs), and pesticides, although none were present at concentrations exceeding drinking-water standards. Of these contaminants, uranium and nitrate pose the most significant water-quality risk to the public-supply well because human activities have caused concentrations in groundwater to increase over time. Overall, study findings point to four primary factors that affect the movement and (or) fate of contaminants and the vulnerability of the public-supply well in Modesto: (1) groundwater age (how long ago water entered, or recharged, the aquifer); (2) irrigation and agricultural and municipal pumping that drives contaminants downward into the primary production zone of the aquifer; (3) short-circuiting of contaminated water down the public-supply well during the low-pumping season; and (4) natural geochemical conditions of the aquifer. A local-scale computer model of groundwater flow and transport to the public-supply well was constructed to simulate long-term nitrate and uranium concentrations reaching the well. With regard to nitrate, two conflicting processes influence concentrations in the area contributing recharge to the well: (1) Beneath land that is being farmed or has recently been farmed (within the last 10 to 20 years), downward-moving irrigation waters contain elevated nitrate concentrations; yet (2) the proportion of agricultural land has decreased and the proportion of urban land has increased since 1960. Urban land use is associated with low nitrate

  6. Groundwater quality in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts, California

    USGS Publications Warehouse

    Parsons, Mary C.; Belitz, Kenneth

    2014-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. Selected groundwater basins in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts constitute one of the study units being evaluated.

  7. Paleomagnetic and structural evidence for middle Tertiary counterclockwise block rotation in the Dixie Valley region, west-central Nevada

    SciTech Connect

    Hudson, M.R.; Geissman, J.W.

    1987-07-01

    Paleomagnetic data from late Oligocene to early Miocene ash-flow tuffs at four localities in the northern Dixie Valley region, west-central Nevada, indicate that parts of the crust have rotated counterclockwise by at least 25/sup 0/ and perhaps significantly more in late Cenozoic time. Field relations in White Rock Canyon, Stillwater Range, suggest that rotation (1) was accommodated by right-lateral slip on northwest-trending faults, (2) spanned ash-flow tuff emplacement, and (3) probably ceased before eruption of overlying middle Miocene basalts. Accurate estimates of Cenozoic extension, as well as evaluation of earlier Mesozoic structures, must include the strain partitioned into rotation in the area.

  8. Agricultural management change effects on river nutrient yields in a catchment of Central Greece

    NASA Astrophysics Data System (ADS)

    Panagopoulos, Y.

    2009-04-01

    Modelling efforts are strongly recommended nowadays by European legislation for investigating non-structural mitigation measures against water pollution on catchment scale. Agricultural diffuse pollution is considered to be the main responsible human activity for the Eutrophication of inland waters with nitrogen (N) and phosphorus (P). The physically-based water quality model SWAT is implemented in an agricultural medium-size agricultural catchment of Central Greece with the purpose to simulate the baseline situation and subsequently to predict the effects that realistic non-structural interventions, applied on the agricultural land, have on water quality and crop yields. SWAT was successfully calibrated according to measured flows and water quality data and subsequently scenarios were developed by changing chemical fertilizer application rates and timing on corn, cotton and wheat cultivations. All scenarios resulted in a decrease of nutrient emissions to surface waters but with a simultaneous small decrease in crop yields. The model predicted explicitly the consequences of non-structural mitigation measures against water pollution sustaining that the understanding of land management changes in relation to its driving factors provides essential information for sustainable management of the agricultural sector in an agricultural country like Greece.

  9. Gravity Data from Dry Lake and Delamar Valleys, east-central Nevada

    USGS Publications Warehouse

    Mankinen, Edward A.; Chuchel, Bruce A.; Moring, Barry C.

    2008-01-01

    Cenozoic basins in eastern Nevada and western Utah constitute major ground-water recharge areas in the eastern part of the Great Basin, and our continuing studies are intended to characterize the geologic framework of the region. Prior to these investigations, regional gravity coverage was variable over the region, adequate in some areas and very sparse in others. The current study in Nevada provides additional high-resolution gravity along transects in Dry Lake and Delamar Valleys to supplement data we established previously in Cave and Muleshoe Valleys. We combine all previously available gravity data and calculate an up-to-date isostatic residual gravity map of the study area. Major density contrasts are identified, indicating zones where Cenozoic tectonic activity could have been accommodated. A gravity inversion method is used to calculate depths to pre-Cenozoic basement rock and to estimate maximum alluvial/volcanic fill in the valleys. Average depths of basin fill in the deeper parts of Cave, Muleshoe, Dry Lake, and Delamar Valleys are approximately 4 km, 2 km, 5 km, and 3 km, respectively.

  10. Lava flows vs. surface water: the geologic battle for the upper McKenzie valley, central Oregon Cascades

    NASA Astrophysics Data System (ADS)

    Deligne, N. I.; Conrey, R. M.; Cashman, K. V.; Grant, G. E.; Amidon, W. H.

    2010-12-01

    Over the past several thousand years, a battle for the upper McKenzie valley in the central Oregon Cascades has raged between, on one side, lava flows from the Sand Mountain volcanic chain and Belknap volcano, and on the other side, surface water fed by prolific springs. The north-south oriented upper McKenzie valley marks the boundary between the (old) western Cascades and the (active) high Cascades. The McKenzie valley hosted a glacier in the Pleistocene. In the Holocene, the valley has become a natural destination and conduit for both lava flows and surface water: it is downhill from volcanic vents, and as it follows the boundary between low (west) and high (east) porosity terrains, groundwater sourced from the high Cascades is forced to emerge in the valley. New surface age exposure dates, in conjunction with 14C dating, indicate that about 3000 years ago multiple lava flows from the Sand Mountain volcanic chain entered the valley from the east. The entire eruptive episode lasted several hundred years and caused massive disturbances to the ancestral McKenzie river. In the early stages of the eruptive episode, a lava flow dammed the McKenzie river, forming Clear Lake (modern source of the McKenzie river) and drowning a Douglas Fir forest. Relic drowned trees suggest that Clear Lake formed in two stages, as trees tops in the deepest part of the lake are consistently rotted off at a depth of 20 meters below water level, while trees in the shallower parts of the lake are rotted off at the surface. This suggests a paleo-lake level 20 meters below modern levels; lake levels are suspected to have reached modern levels later in the course of the eruptive episode when subsequent Sand Mountain lava flows entered the lake. In the years since the Sand Mountain eruptive episode, the McKenzie river re-established itself by adopting a lava channel. Considerable water also flows through the lava flows, emerging as springs along the river channel. The river also hosts two

  11. Ground-water quality beneath irrigated agriculture in the central High Plains aquifer, 1999-2000

    USGS Publications Warehouse

    Bruce, Breton W.; Becker, Mark F.; Pope, Larry M.; Gurdak, Jason J.

    2003-01-01

    In 1999 and 2000, 30 water-quality monitoring wells were installed in the central High Plains aquifer to evaluate the quality of recently recharged ground water in areas of irrigated agriculture and to identify the factors affecting ground-water quality. Wells were installed adjacent to irrigated agricultural fields with 10- or 20-foot screened intervals placed near the water table. Each well was sampled once for about 100 waterquality constituents associated with agricultural practices. Water samples from 70 percent of the wells (21 of 30 sites) contained nitrate concentrations larger than expected background concentrations (about 3 mg/L as N) and detectable pesticides. Atrazine or its metabolite, deethylatrazine, were detected with greater frequency than other pesticides and were present in all 21 samples where pesticides were detected. The 21 samples with detectable pesticides also contained tritium concentrations large enough to indicate that at least some part of the water sample had been recharged within about the last 50 years. These 21 ground-water samples are considered to show water-quality effects related to irrigated agriculture. The remaining 9 groundwater samples contained no pesticides, small tritium concentrations, and nitrate concentrations less than 3.45 milligrams per liter as nitrogen. These samples are considered unaffected by the irrigated agricultural land-use setting. Nitrogen isotope ratios indicate that commercial fertilizer was the dominant source of nitrate in 13 of the 21 samples affected by irrigated agriculture. Nitrogen isotope ratios for 4 of these 21 samples were indicative of an animal waste source. Dissolved-solids concentrations were larger in samples affected by irrigated agriculture, with large sulfate concentrations having strong correlation with large dissolved solids concentrations in these samples. A strong statistical correlation is shown between samples affected by irrigated agriculture and sites with large rates of

  12. Landslide Susceptibility Evaluation on agricultural terraces of DOURO VALLEY (PORTUGAL), using physically based mathematical models.

    NASA Astrophysics Data System (ADS)

    Faria, Ana; Bateira, Carlos; Laura, Soares; Fernandes, Joana; Gonçalves, José; Marques, Fernando

    2016-04-01

    The work focuses the evaluation of landslide susceptibility in Douro Region agricultural terraces, supported by dry stone walls and earth embankments, using two physically based models. The applied models, SHALSTAB (Montgomery et al.,1994; Dietrich et al., 1995) and SINMAP (PACK et al., 2005), combine an infinite slope stability model with a steady state hydrological model, and both use the following geophysical parameters: cohesion, friction angle, specific weight and soil thickness. The definition of the contributing areas is different in both models. The D∞ methodology used by SINMAP model suggests a great influence of the terraces morphology, providing a much more diffuse flow on the internal flow modelling. The MD8 used in SHALSTAB promotes an important degree of flow concentration, representing an internal flow based on preferential paths of the runoff as the areas more susceptible to saturation processes. The model validation is made through the contingency matrix method (Fawcett, 2006; Raia et al., 2014) and implies the confrontation with the inventory of past landslides. The True Positive Rate shows that SHALSTAB classifies 77% of the landslides on the high susceptibility areas, while SINMAP reaches 90%. The SINMAP has a False Positive Rate (represents the percentage of the slipped area that is classified as unstable but without landslides) of 83% and the SHALSTAB has 67%. The reliability (analyzes the areas that were correctly classified on the total area) of SHALSTAB is better (33% against 18% of SINMAP). Relative to Precision (refers to the ratio of the slipped area correctly classified over the whole area classified as unstable) SHALSTAB has better results (0.00298 against 0.00283 of SINMAP). It was elaborate the index TPR/FPR and better results obtained by SHALSTAB (1.14 against 1.09 of SINMAP). SHALSTAB shows a better performance in the definition of susceptibility most prone areas to instability processes. One of the reasons for the difference of

  13. Summary of reported agriculture and irrigation water use in west-central Arkansas counties, 1991

    USGS Publications Warehouse

    Holland, T.W.; Manning, C.A.; Stafford, K.L.

    1993-01-01

    This report summarizes the 1991 water-use reporting through the Conservation District Offices in the following west-central Arkansas counties: Conway, Crawford, Faulkner, Franklin, Johnson, Logan, Perry, Pope, Scott, Sebastian, and Yell. The number of withdrawal registrations for west-central Arkansas counties was 307 (90 groundwater and 217 surface water). Water withdrawals reported during the registration process total 1.00 Mgal/d (0.15 Mgal/d groundwater and 0.85 Mgal/d surface water) for agriculture and 32.07 Mgal/d (5.67 Mgal/d groundwater and 26.40 Mgal/d surface water) for irrigation. The registration reports for 1991 indicate that this water was applied to 22,856 acres of land to irrigate rice, corn, sorghum, soybeans, wheat, cash grains, hay, milo, vegetables, sod, berries, grapes, and fruit trees as well as for the agricultural uses of catfish and ducks.

  14. Tomographic Rayleigh wave group velocities in the Central Valley, California, centered on the Sacramento/San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Fletcher, Jon B.; Erdem, Jemile; Seats, Kevin; Lawrence, Jesse

    2016-04-01

    If shaking from a local or regional earthquake in the San Francisco Bay region were to rupture levees in the Sacramento/San Joaquin Delta, then brackish water from San Francisco Bay would contaminate the water in the Delta: the source of freshwater for about half of California. As a prelude to a full shear-wave velocity model that can be used in computer simulations and further seismic hazard analysis, we report on the use of ambient noise tomography to build a fundamental mode, Rayleigh wave group velocity model for the region around the Sacramento/San Joaquin Delta in the western Central Valley, California. Recordings from the vertical component of about 31 stations were processed to compute the spatial distribution of Rayleigh wave group velocities. Complex coherency between pairs of stations was stacked over 8 months to more than a year. Dispersion curves were determined from 4 to about 18 s. We calculated average group velocities for each period and inverted for deviations from the average for a matrix of cells that covered the study area. Smoothing using the first difference is applied. Cells of the model were about 5.6 km in either dimension. Checkerboard tests of resolution, which are dependent on station density, suggest that the resolving ability of the array is reasonably good within the middle of the array with resolution between 0.2 and 0.4°. Overall, low velocities in the middle of each image reflect the deeper sedimentary syncline in the Central Valley. In detail, the model shows several centers of low velocity that may be associated with gross geologic features such as faulting along the western margin of the Central Valley, oil and gas reservoirs, and large crosscutting features like the Stockton arch. At shorter periods around 5.5 s, the model's western boundary between low and high velocities closely follows regional fault geometry and the edge of a residual isostatic gravity low. In the eastern part of the valley, the boundaries of the low

  15. Water Quality in a Wet Meadow, Platte River Valley, Central Nebraska

    USGS Publications Warehouse

    Emmons, Patrick J.

    1996-01-01

    The Platte River Valley in Nebraska, and in particular the reach from Kearney to Grand Island, is an extremely important natural habitat area. Over 300 migratory bird species, including several threatened and endangered species, have been observed along the Platte River. In the spring, nearly 500,000 sandhill cranes, along with millions of ducks and geese, use this reach as a staging and feeding area during their northerly migration. Wet meadows (grasslands which have waterlogged soils much of the year) are a critical part of this migratory-bird habitat. However, the area of wet meadows between Kearney and Grand Island has declined nearly 50 percent due to the activities of man. The condition of the remaining wet meadows is of vital importance. The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to describe the status and trends in the quality of the Nation's surface water and groundwater resources and to provide a sound understanding of the natural and human factors that affect the quality of these resources. A study of the groundwater beneath a selected wet meadow was undertaken as part of the Central Nebraska Basins NAWQA study unit. Observation wells were installed in the wet meadow at various distances along two transects downgradient from the edge of a corn field. One to five wells completed at depths of about 15 to 100 feet were located at each of the 5 sites. The wells were completed in the Platte River alluvium or the underlying Ogallala Formation. The depth to the water table ranges from 0 to 5 feet below land surface. The general direction of groundwater flow is parallel to flow in the Platte River. Selected wells were sampled in February, March, June, and December 1994 for major cations and anions, nutrients, and organonitrogen herbicides. Pesticides and fertilizers are used extensively in Nebraska to enhance the production of row crops. Some of these pesticides and fertilizers have migrated into the groundwater

  16. Agriculture

    EPA Pesticide Factsheets

    The EPA Agriculture Resource Directory offers comprehensive, easy-to-understand information about environmental stewardship on farms and ranches; commonsense, flexible approaches that are both environmentally protective and agriculturally sound.

  17. Structure and regional significance of the Late Permian(?) Sierra Nevada - Death Valley thrust system, east-central California

    USGS Publications Warehouse

    Stevens, C.H.; Stone, P.

    2005-01-01

    An imbricate system of north-trending, east-directed thrust faults of late Early Permian to middle Early Triassic (most likely Late Permian) age forms a belt in east-central California extending from the Mount Morrison roof pendant in the eastern Sierra Nevada to Death Valley. Six major thrust faults typically with a spacing of 15-20 km, original dips probably of 25-35??, and stratigraphic throws of 2-5 km compose this structural belt, which we call the Sierra Nevada-Death Valley thrust system. These thrusts presumably merge into a de??collement at depth, perhaps at the contact with crystalline basement, the position of which is unknown. We interpret the deformation that produced these thrusts to have been related to the initiation of convergent plate motion along a southeast-trending continental margin segment probably formed by Pennsylvanian transform truncation. This deformation apparently represents a period of tectonic transition to full-scale convergence and arc magmatism along the continental margin beginning in the Late Triassic in central California. ?? 2005 Elsevier B.V. All rights reserved.

  18. Vector competence of alpine, Central Valley, and coastal mosquitoes (Diptera: Culicidae) from California for Jamestown Canyon virus.

    PubMed

    Kramer, L D; Bowen, M D; Hardy, J L; Reeves, W C; Presser, S B; Eldridge, B F

    1993-03-01

    Mosquitoes collected from alpine, Central Valley, and coastal habitats in California were evaluated for their vector competence for four strains of Jamestown Canyon (JC) virus. Three of the viral strains examined were isolated from alpine Aedes species collected in California, and one, the prototype JC virus, was isolated from Culiseta inornata (Williston) collected in Colorado. Alpine Aedes tahoensis Dyar, Ae. cataphylla Dyar, Ae. hexodontus Dyar, Ae. increpitus Dyar, Ae. clivis Lanzaro and Eldridge, and coastal Aedes washinoi Lanzaro and Eldridge were variably susceptible to alpine strains of JC virus. Infection rates ranged from 22 to 77%, and peroral transmission rates of the infected females ranged from 0 to 26%. The differences were related to both mosquito species and viral strain. Coastal populations of Cs. inornata, Ae. washinoi, and Ae. sierrensis (Ludlow) were incompetent vectors when fed an alpine strain of JC virus, whereas Ae. squamiger (Coquillet) and Ae. dorsalis (Meigen) were competent vectors. Peroral transmission rates following parenteral infection of females of most species were about twofold higher than those for perorally infected females. A population of Cs. inornata from the Central Valley was highly susceptible when fed an alpine strain of JCV and transmitted virus both horizontally and vertically. Alpine strains of JC virus also were transmitted vertically by Ae. tahoensis, Ae. washinoi, and Ae. squamiger following parenteral infection of females.

  19. Chemical and nutritional composition of tejate, a traditional maize and cacao beverage from the Central Valleys of Oaxaca, Mexico.

    PubMed

    Sotelo, Angela; Soleri, Daniela; Wacher, Carmen; Sánchez-Chinchillas, Argelia; Argote, Rosa Maria

    2012-06-01

    Foam-topped cacao and maize beverages have a long history in Mesoamerica. Tejate is such a beverage found primarily in the Zapotec region of the Central Valleys of Oaxaca, Mexico. Historically tejate has been ceremonially important but also as an essential staple, especially during periods of hard fieldwork. However, the nutritional contribution of traditional foods such as tejate has not been investigated. We analyzed tejate samples from three Central Valley communities, vendors in urban Oaxaca markets and one migrant vendor in California, USA for their proximate composition, amino acid content and scores, and mineral and methylxanthine content. Nutritional and chemical variation exists among tejate recipes, however, the beverage is a source of energy, fat, methylxanthines, K, Fe and other minerals although their availability due to presence of phytates remains to be determined. Tejate is a source of protein comparable to an equal serving size of tortillas, with protein quality similarly limited in both. Tejate provides the nutritional benefits of maize, and some additional ones, in a form appealing during hot periods of intense work, and year round because of its cultural significance. Its substitution by sodas and other high glycemic beverages may have negative nutritional, health and cultural consequences.

  20. Hydrogeology of the Helena Valley-fill aquifer system, west-central Montana. Water resources investigation

    SciTech Connect

    Briar, D.W.; Madison, J.P.

    1992-01-01

    The report, which presents the study results, describes the hydrogeology of the valley-fill aquifer system. Specific objectives were to: describe the geometry and the hydraulic characteristics of the aquifer system; define the potentiometric surface and the direction of ground-water flow; locate and quantify sources of ground-water recharge and discharge including surface- and ground-water interactions; and characterize the water quality in terms of susceptibility of the aquifer system to contamination and in terms of concentrations, distribution, and sources of major ions, trace elements, and organic compounds. The results of the study will be useful to the development of a comprehensive management program for the use and protection of the ground-water resources of the Helena Valley.

  1. Magmatic-Tectonic Interactions: Implications for Seismic Hazard Assessment in the Central Walker Lane and Long Valley Caldera Regions

    NASA Astrophysics Data System (ADS)

    Chacko, R.; Hammond, W. C.; Blewitt, G.; Bormann, J. M.

    2014-12-01

    Accurate estimates of fault slip rates based on geodetic data rely on measurements that represent the long-term deformation of the crust. In the Central Walker Lane/Sierra Nevada transition, the Long Valley Caldera region has experienced multiple episodes of uplift and subsidence during the last four decades. The latest episode began in late 2011 and is detectable as a transient signal in the time series of GPS stations around the caldera. These transient signals become more apparent and reveal the extent of the impact on the ambient crustal deformation field of the Walker Lane when the velocity vectors are transformed to a Sierra-Nevada reference frame. Estimating contemporary slip-rates on faults for the purpose of seismic hazard assessment in the region around Long Valley requires detecting and subtracting the transient signals caused by the uplift and subsidence in the caldera. We estimate the geographic extent to which the ambient crustal deformation field is significantly perturbed by ongoing magmatic activity in Long Valley. We present a time variable 3D deformation field constrained by InSAR and GPS observations, and discuss the implications that tectonic-magmatic interaction have for estimates of present-day fault slip-rate. We model the time dependent deformation at Long Valley by analyzing InSAR time series from Envisat and ERS interferograms spanning a period of more than 19 years. We use an analytical volcano deformation source model derived from vertical (GPS) and line of site (InSAR) component of geodetic observations to estimate the horizontal component of the signals associated with magmatic activity beneath the caldera. Previous studies showed that the latest episode of uplift can be modeled with a Mogi source located at a depth of ~6 km with a volume change of 0.03 km3 beneath the resurgent dome. This model predicts a perturbation to the ambient crustal deformation field extending as far as 60 km from the center of the resurgent dome. Thus the

  2. Wild food plants and wild edible fungi in two valleys of the Qinling Mountains (Shaanxi, central China)

    PubMed Central

    2013-01-01

    Background The aim of the study was to investigate knowledge and use of wild food plants in two mountain valleys separated by Mount Taibai – the highest peak of northern China and one of its biodiversity hotspots, each adjacent to species-rich temperate forest vegetation. Methods Seventy two free lists were collected among the inhabitants of two mountain valleys (36 in each). All the studied households are within walking distance of primary forest vegetation, however the valleys differed in access to urban centers: Houzhenzi is very isolated, and the Dali valley has easier access to the cities of central Shaanxi. Results Altogether, 185 wild food plant species and 17 fungi folk taxa were mentioned. The mean number of freelisted wild foods was very high in Houzhenzi (mean 25) and slightly lower in Dali (mean 18). An average respondent listed many species of wild vegetables, a few wild fruits and very few fungi. Age and male gender had a positive but very low effect on the number of taxa listed. Twelve taxa of wild vegetables (Allium spp., Amaranthus spp., Caryopteris divaricata, Helwingia japonica, Matteucia struthiopteris, Pteridium aquilinum, Toona sinensis, Cardamine macrophylla, Celastrus orbiculatus, Chenopodium album, Pimpinella sp., Staphylea bumalda &S. holocarpa), two species of edible fruits (Akebia trifoliata, Schisandra sphenanthera) and none of the mushrooms were freelisted by at least half of the respondents in one or two of the valleys. Conclusion The high number of wild vegetables listed is due to the high cultural position of this type of food in China compared to other parts of the world, as well as the high biodiversity of the village surroundings. A very high proportion of woodland species (42%, double the number of the ruderal species used) among the listed taxa is contrary to the general stereotype that wild vegetables in Asia are mainly ruderal species. The very low interest in wild mushroom collecting is noteworthy and is difficult to

  3. Stable isotopes as indicators of sources and processes influencing nitrate distributions in dairy monitoring wells and domestic supply wells in the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Young, M. B.; Harter, T.; Kendall, C.; Silva, S. R.; Esser, B. K.; Singleton, M. J.; Holstege, D.; Lockhart, K.; Applegate, O.

    2011-12-01

    Nitrate concentrations above the 10 mg/L NO3-N maximum contaminant level (MCL) have been found in many wells throughout the Central Valley, California. This area contains many possible anthropogenic nitrate sources including current and historic agriculture, private septic systems, municipal waste water, and confined animal feeding operations (primarily dairies). In order to better understand the potential contributions of dairy manure derived nitrate to both shallow and deep groundwater, we used a combined chemical, stable isotope, and age-dating approach for water samples collected from a network of shallow groundwater monitoring wells located on seven different dairies, and from a survey of approximately 200 deeper domestic supply wells (used for drinking water and dairy operations). Groundwater from shallow monitoring wells and deep supply wells was collected in two geographic regions. In the northern region, the lower San Joaquin Valley, the water table is shallow (2- 5 m below surface) and therefore considered highly vulnerable to contamination, while in the southern region, the Tulare Lake Basin, the water table is much deeper (20 - 30 m). Mean δ15N of nitrate in dairy monitoring wells in both the north and south regions was significantly higher than the mean δ15N measured in the deeper supply wells, and also showed greater variability. Mean δ15N and δ18O values measured in the deep supply wells were not significantly different between the north and south regions. Mean nitrate concentrations, δ15N, and δ18O were significantly higher in the northern (lower San Joaquin Valley) monitoring wells in comparison to the southern (Tulare Lake Basin) monitoring wells. Nitrate isotope measurements indicated that many of the northern monitoring wells had consistently high contributions of manure-derived nitrate to the shallow groundwater during the 16 month study. Monitoring wells located in relatively new dairies in the south region showed little evidence of

  4. Trends in nitrate concentrations and determination of its origin using stable isotopes (18O and 15N) in groundwater of the Western Central Valley, Costa Rica.

    PubMed

    Reynolds-Vargas, Jenny; Fraile-Merino, Julio; Hirata, Ricardo

    2006-08-01

    A study was conducted to evaluate long-term trends in nitrate concentrations and to try to identify the origin of nitrate using stable isotopes (15N(NO3-) and 18O(NO3-)) in the aquifers of the western Central Valley, Costa Rica, where more than 1 million people depend on groundwater to satisfy their daily needs. Data from 20 sites periodically sampled for 4 to 17 years indicate an increasing trend in nitrate concentrations at five sites, which in a period ranging from 10 to 40 years, will exceed recommended maximum concentrations. Results of isotopic analysis indicate a correspondence between land use patterns and the isotopic signature of nitrate in groundwater and suggest that urbanization processes without adequate waste disposal systems, followed by coffee fertilization practices, are threatening water quality in the region. We conclude that groundwater management in this area is not sustainable, and that land use substitution processes from agricultural activity to residential occupation that do not have proper sewage disposal systems may cause a significant increment in the nitrate contaminant load.

  5. Co-evolution of soils and vegetation in the Aísa Valley Experimental Station (Central Pyrenees)

    NASA Astrophysics Data System (ADS)

    Serrano Muela, Maria Pilar; Nadal Romero, Estela; Lasanta, Teodoro; María García Ruiz, José

    2013-04-01

    Soils and vegetation tend to evolve jointly in relation to climate evolution and the impacts of human activity. This study analyzes soil and vegetation characteristics under various plant covers, using information from the Aísa Valley Experimental Station (AVES), Spanish Pyrenees, from 1991 to 2010. The land uses considered were: dense shrub cover, grazing meadow, abandoned field, cereal (barley), abandoned shifting agriculture, active shifting agriculture, burnt1 and burnt2 plots, and in-fallow plot. All the plots were installed on a field abandoned 45 years ago. Some of the plots did not change in plant cover through the study period (e.g., the meadow, cereal and shifting agriculture plots), but others underwent changes in density and composition, such as: (i) The dense shrub cover plot represents the natural evolution of the abandoned field. When the AVES was equipped, this plot was completely dominated by Genista scorpius, with a few stands of Rosa gr. Canina. Twenty years later, Genista scorpius is affected of senescence and shows almost no regeneration capacity. (ii) The abandoned field had previously been cultivated with cereals until 1993. Once abandoned, the progression of plant colonization was very rapid. Firstly with grasses and, 10 years later, with Genista scorpius. At present, this latter occupies more than 50% of the plot. (iii) The evolution of plant colonization in the abandoned shifting agriculture plot was slower than that in the 'normal' abandoned field, mainly because of the differences in fertilization when they were cultivated. (iv) One of the burnt plots evolved from 0% to a coverage of almost 100% in a shot period, whereas the other plot remained with a shrub density of about 60% several years after the fire. Soil samples (superficial and depth) were analyzed to obtain physical and chemical properties: structure, texture, pH, CaCO3, Organic Matter and various anions and cations. The main purpose was to detect differences in the soil

  6. Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by Use of Elemental and Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Ransom, K.; Grote, M. N.; Deinhart, A.; Eppich, G.; Kendall, C.; Sanborn, M.; Souders, K.; Wimpenny, J.; Yin, Q. Z.; Young, M. B.; Harter, T.

    2015-12-01

    Groundwater quality is a concern in alluvial aquifers that underlie agricultural areas, such as in the San Joaquin Valley of California. Nitrate from fertilizers and animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are prevailing sources of nitrate in groundwater for the San Joaquin Valley with septic waste contributing as a major source in some areas. The rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (less than 150 m deep), of which many have been affected by nitrate. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. In contrast, Bayesian mixing models treat source contributions probabilistically, building statistical variation into the inferences for each well. The authors developed a Bayesian mixing model on a pilot network of 56 private domestic wells in the San Joaquin Valley for which nitrogen, oxygen, and boron isotopes as well as nitrate and iodine were measured. Nitrogen, oxygen, and boron isotopes as well as iodine can be used as tracers to differentiate between manure, fertilizers, septic waste, and natural sources of nitrate (which can contribute nitrate in concentrations up to 4 mg/L). In this work, the isotopic and elemental tracers were used to estimate the proportional contribution of manure, fertilizers, septic waste, and natural sources to overall groundwater nitrate concentration in individual wells. Prior distributions for the four tracers for each of the four

  7. Estuarine fluvial floodplain formation in the Holocene Lower Tagus valley (Central Portugal) and implications for Quaternary fluvial system evolution

    NASA Astrophysics Data System (ADS)

    van der Schriek, Tim; Passmore, David G.; Rolão, Jose; Stevenson, Anthony C.

    2007-11-01

    We present a brief synthesis of the Quaternary fluvial record in the Lower Tagus Basin (central Portugal), concentrating on factors controlling infill and incision. The Holocene part of the record forms the focus of this paper and guides the questioning of the basic assumptions of the established Quaternary fluvial evolution model, in particular the link between sea-level change and fluvial incision-deposition. We suggest that several incision-aggradation phases may have occurred during glacial periods. Major aggradation events may overlap with cold episodes, while incision appears to concentrate on the warming limb of climate transitions. The complex stratigraphy of the Quaternary record in the Lower Tagus valley is influenced by repeated base-level and climate changes. This paper submits the first chronostratigraphic framework for valley fill deposits in the Lower Tagus area. Sea-level rise forced aggradation and controlled deposition of the fine-grained sedimentary wedge underlying the low-gradient Lower Tagus floodplain. Investigations have focused on the lower Muge tributary, where rapidly aggrading estuarine and fluvial environments were abruptly established (∼8150 cal BP) as sea level rose. Base level at the valley mouth controlled the upstream extent of the fine-grained backfill. Tidal environments disappeared abruptly (∼5800 cal BP) when the open estuary at the Muge confluence was infilled by the Tagus River. The decrease and final still stand of sea-level rise led to floodplain stabilisation with peat (∼6400-5200 cal BP) and soil formation (∼5200-2200 cal BP). Localised renewed sedimentation (∼2200-200 cal BP) is linked to human activity.

  8. Principal facts for gravity stations in the Antelope Valley-Bedell Flat area, west-central Nevada

    USGS Publications Warehouse

    Jewel, Eleanore B.; Ponce, David A.; Morin, Robert L.

    2000-01-01

    In April 2000 the U.S. Geological Survey (USGS) established 211 gravity stations in the Antelope Valley and Bedell Flat area of west-central Nevada (see figure 1). The stations were located about 15 miles north of Reno, Nevada, southwest of Dogskin Mountain, and east of Petersen Mountain, concentrated in Antelope Valley and Bedell Flat (figure 2). The ranges in this area primarily consist of normal-faulted Cretaceous granitic rocks, with some volcanic and metavolcanic rocks. The purpose of the survey was to characterize the hydrogeologic framework of Antelope Valley and Bedell Flat in support of future hydrologic investigations. The information developed during this study can be used in groundwater models. Gravity data were collected between latitude 39°37.5' and 40°00' N and longitude 119°37.5' and 120°00' W. The stations were located on the Seven Lakes Mountain, Dogskin Mountain, Granite Peak, Bedell Flat, Fraser Flat, and Reno NE 7.5 minute quadrangles. All data were tied to secondary base station RENO-A located on the campus of the University of Nevada at Reno (UNR) in Reno, Nevada (latitude 39°32.30' N, longitude 119°48.70' W, observed gravity value 979674.69 mGal). The value for observed gravity was calculated by multiple ties to the base station RENO (latitude 39°32.30' N, longitude 119°48.70' W, observed gravity value 979674.65 mGal), also on the UNR campus. The isostatic gravity map (figure 3) includes additional data sets from the following sources: 202 stations from a Geological Survey digital data set (Ponce, 1997), and 126 stations from Thomas C. Carpenter (written commun., 1998).

  9. Heat flow in Railroad Valley, Nevada and implications for geothermal resources in the south-central Great Basin

    USGS Publications Warehouse

    Williams, C.F.; Sass, J.H.

    2006-01-01

    The Great Basin is a province of high average heat flow (approximately 90 mW m-2), with higher values characteristic of some areas and relatively low heat flow (<60 mW m-2) characteristic of an area in south-central Nevada known as the Eureka Low. There is hydrologie and thermal evidence that the Eureka Low results from a relatively shallow, hydrologically controlled heat sink associated with interbasin water flow in the Paleozoic carbonate aquifers. Evaluating this hypothesis and investigating the thermal state of the Eureka Low at depth is a high priority for the US Geological Survey as it prepares a new national geothermal resource assessment. Part of this investigation is focused on Railroad Valley, the site of the largest petroleum reservoirs in Nevada and one of the few locations within the Eureka Low with a known geothermal system. Temperature and thermal conductivity data have been acquired from wells in Railroad Valley in order to determine heat flow in the basin. The results reveal a complex interaction of cooling due to shallow ground-water flow, relatively low (49 to 76 mW m-2) conductive heat flow at depth in most of the basin, and high (up to 234 mW m-2) heat flow associated with the 125??C geothermal system that encompasses the Bacon Flat and Grant Canyon oil fields. The presence of the Railroad Valley geothermal resource within the Eureka Low may be reflect the absence of deep ground-water flow sweeping heat out of the basin. If true, this suggests that other areas in the carbonate aquifer province may contain deep geothermal resources that are masked by ground-water flow.

  10. Distribution and sources of organochlorine pesticides in agricultural soils from central China.

    PubMed

    Zhou, Qun; Wang, Jingjing; Meng, Beidi; Cheng, Junqi; Lin, Guoping; Chen, Jiachun; Zheng, Dan; Yu, Yanhong

    2013-07-01

    There is little information on the organochlorine pesticides (OCPs) residues in agricultural soils of Wuhan, the largest city in central China. Surface soil samples were collected from agricultural soils in Wuhan and analyzed to determine twenty-one OCPs. According to the measured concentrations and detection frequencies, dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), heptachlor (HEPT), hexachlorobenzene (HCB) and aldrin were the predominant compounds in soil. DDTs accounted for 77.10% of total OCPs, followed by HCHs (7.83%), aldrin (4.21%), HEPTs (2.82%) and HCB (1.53%). The total DDT concentrations ranged from nd to 1198.0ngg(-1) and the main contaminated areas were distributed in Hannan and Xinzhou districts of Wuhan. The total HCH concentrations ranged from nd to 100.58ngg(-1) in soil and relatively higher levels were observed in soil samples from Huangpi and Hannan districts. Source analysis showed that OCPs residues except heptachlor originated mainly from historical application, besides slight recent introduction at some sites. Based on the China National Soil Quality Standard, DDT pollution in most samples of Wuhan agricultural soils could be considered as no and low contamination, while the level of HCHs was classified as no pollution. Our study indicated that there existed potential exposure risk of OCPs in Wuhan agricultural soils although the use of OCPs has been banned.

  11. Comparison of sediment supply to San Francisco Bay from watersheds draining the Bay Area and the Central Valley of California

    USGS Publications Warehouse

    McKee, L.J.; Lewicki, M.; Schoellhamer, D.H.; Ganju, N.K.

    2013-01-01

    Quantifying suspended sediment loads is important for managing the world's estuaries in the context of navigation, pollutant transport, wetland restoration, and coastal erosion. To address these needs, a comprehensive analysis was completed on sediment supply to San Francisco Bay from fluvial sources. Suspended sediment, optical backscatter, velocity data near the head of the estuary, and discharge data obtained from the output of a water balance model were used to generate continuous suspended sediment concentration records and compute loads to the Bay from the large Central Valley watershed. Sediment loads from small tributary watersheds around the Bay were determined using 235 station-years of suspended sediment data from 38 watershed locations, regression analysis, and simple modeling. Over 16 years, net annual suspended sediment load to the head of the estuary from its 154,000 km2 Central Valley watershed varied from 0.13 to 2.58 (mean = 0.89) million metric t of suspended sediment, or an average yield of 11 metric t/km2/yr. Small tributaries, totaling 8145 km2, in the nine-county Bay Area discharged between 0.081 and 4.27 (mean = 1.39) million metric t with a mean yield of 212 metric t/km2/yr. The results indicate that the hundreds of urbanized and tectonically active tributaries adjacent to the Bay, which together account for just 5% of the total watershed area draining to the Bay and provide just 7% of the annual average fluvial flow, supply 61% of the suspended sediment. The small tributary loads are more variable (53-fold between years compared to 21-fold for the inland Central Valley rivers) and dominated fluvial sediment supply to the Bay during 10 out of 16 yr. If San Francisco Bay is typical of other estuaries in active tectonic or climatically variable coastal regimes, managers responsible for water quality, dredging and reusing sediment accumulating in shipping channels, or restoring wetlands in the world's estuaries may need to more carefully

  12. Starch grain and phytolith evidence for early ninth millennium B.P. maize from the Central Balsas River Valley, Mexico

    PubMed Central

    Piperno, Dolores R.; Ranere, Anthony J.; Holst, Irene; Iriarte, Jose; Dickau, Ruth

    2009-01-01

    Questions that still surround the origin and early dispersals of maize (Zea mays L.) result in large part from the absence of information on its early history from the Balsas River Valley of tropical southwestern Mexico, where its wild ancestor is native. We report starch grain and phytolith data from the Xihuatoxtla shelter, located in the Central Balsas Valley, that indicate that maize was present by 8,700 calendrical years ago (cal. B.P.). Phytolith data also indicate an early preceramic presence of a domesticated species of squash, possibly Cucurbita argyrosperma. The starch and phytolith data also allow an evaluation of current hypotheses about how early maize was used, and provide evidence as to the tempo and timing of human selection pressure on 2 major domestication genes in Zea and Cucurbita. Our data confirm an early Holocene chronology for maize domestication that has been previously indicated by archaeological and paleoecological phytolith, starch grain, and pollen data from south of Mexico, and reshift the focus back to an origin in the seasonal tropical forest rather than in the semiarid highlands. PMID:19307570

  13. Starch grain and phytolith evidence for early ninth millennium B.P. maize from the Central Balsas River Valley, Mexico.

    PubMed

    Piperno, Dolores R; Ranere, Anthony J; Holst, Irene; Iriarte, Jose; Dickau, Ruth

    2009-03-31

    Questions that still surround the origin and early dispersals of maize (Zea mays L.) result in large part from the absence of information on its early history from the Balsas River Valley of tropical southwestern Mexico, where its wild ancestor is native. We report starch grain and phytolith data from the Xihuatoxtla shelter, located in the Central Balsas Valley, that indicate that maize was present by 8,700 calendrical years ago (cal. B.P.). Phytolith data also indicate an early preceramic presence of a domesticated species of squash, possibly Cucurbita argyrosperma. The starch and phytolith data also allow an evaluation of current hypotheses about how early maize was used, and provide evidence as to the tempo and timing of human selection pressure on 2 major domestication genes in Zea and Cucurbita. Our data confirm an early Holocene chronology for maize domestication that has been previously indicated by archaeological and paleoecological phytolith, starch grain, and pollen data from south of Mexico, and reshift the focus back to an origin in the seasonal tropical forest rather than in the semiarid highlands.

  14. Pliocene and Pleistocene geologic and climatic evolution in the San Luis Valley of south-central Colorado

    USGS Publications Warehouse

    Rogers, K.L.; Larson, E.E.; Smith, G.; Katzman, D.; Smith, G.R.; Cerling, T.; Wang, Y.; Baker, R.G.; Lohmann, K.C.; Repenning, C.A.; Patterson, P.; Mackie, G.

    1992-01-01

    Sediments of the Alamosa Formation spanning the upper part of the Gauss and most of the Matuyama Chrons were recovered by coring in the high (2300 m) San Luis Valley of south-central Colorado. The study site is located at the northern end of the Rio Grande rift. Lithologic changes in the core sediments provide evidence of events leading to integration of the San Luis drainage basin into the Rio Grande. The section, which includes the Huckleberry Ridge Ash (2.02 Ma) and spans the entire Matuyama Chron, contains pollen, and invertebrate and vertebrate fossils. Stable isotope analyses of inorganic and biogenic carbonate taken over most of the core indicate substantially warmer temperatures than occur today in the San Luis Valley. At the end of the Olduvai Subchron, summer precipitation decreased, summer pan evaporation increased, and temperatures increased slightly compared to the earlier climate represented in the core. By the end of the Jaramillo Subchron, however, cold/wet and warm/dry cycles become evident and continue into the cold/wet regime associated with the deep-sea oxygen-isotope Stage 22 glaciation previously determined from outcrops at the same locality. Correspondence between the Hansen Bluff climatic record and the deep-sea oxygen-isotope record (oxygen-isotope stages from about 110-18) is apparent, indicating that climate at Hansen Bluff was responding to global climatic changes. ?? 1992.

  15. Central Avra Valley Storage and Recovery Project (CAVSARP) Site, Tucson, Arizona: Floodwater and Soil Moisture Investigations with Extraterrestrial Applications

    NASA Technical Reports Server (NTRS)

    Rucker, D. F.; Dohm, J. M.; Ferre, T. P. A.; Ip, Felipe; Baker, V. R.; Davies, A. G.; Castano, R.; Chien, S.; Doggett, T. C.

    2004-01-01

    Planetary geologists, geomorphologists, and hydrologists have hypothesized that Mars is a dynamic, water-enriched planet since the Mariner and Viking missions based on geologic, geomorphic, and topographic information. Recent acquisition of Gamma Ray and Neutron Spectrometer information has added further credence to this hypothesis. A unique investigation is underway to work towards being able to successfully map the extent and depth of water on Mars. Researchers from the University of Arizona and members of the Autonomous Sciencecraft Experiment (ASE) have been compiling multiple layers of information in time and space at the Central Avra Valley Storage and Recovery Project (CAVSARP) site, Tucson, Arizona, for eventual comparative analysis. This information has been acquired from a variety of observational/scientific platforms in controlled conditions. CAVSARP facility:

  16. Crustal shear-wave anisotropy in the New Madrid and Wabash Valley seismic regions of the Central US

    NASA Astrophysics Data System (ADS)

    Jemberie, A. L.

    2012-12-01

    Local and regional earthquakes recorded by the US Array , the New Madrid and GSN - IRIS/USGS network of stations are analyzed to study crustal shear-wave anisotropy of the New Madrid and Wabash Valley seismic zones of the Central United States. The N-S and E-W components of the ground motion are cross-correlated to obtain the polarization angle of the fast shear-wave, and delay time of the slow shear-wave. Data with high signal to noise ratio, and incidence angle at a station less than 35 degrees are selected for further analysis. Preliminary results from data recorded by select stations show that the fast shear-wave is polarized in the direction of regional maximum horizontal compressional stress. Time delays over 100 ms are observed between the fast and the slow shear-waves.

  17. Younger Dryas Cladocera assemblages from two valley mires in central Poland and their potential significance for climate reconstructions

    NASA Astrophysics Data System (ADS)

    Pawłowski, Dominik

    2012-12-01

    Two sections of sediment from small oxbow-lake infillings located in different river valleys in central Poland were studied by cladoceran analysis in order to examine the response of aquatic ecosystems to the Younger Dryas. Lithological and geochemical records, as well as chydorid (Chydoridae) ephippia analysis were also used to reconstruct Younger Dryas climate trends. A high concentration of cladocerans, as well as the presence of Cladocera taxa preferring warmer water, was found. It is likely that local processes in the oxbow lakes were important, because the presence of warm-preferring taxa was also related to their habitats and their development. Yet local environmental forces, such as the influence of the rivers, habitat modification, macrophyte abundance, and eutrophication, were not only major factors to affect the Cladocera diversity in the Younger Dryas. The observation of changes in the composition and concentration of Cladocera in oxbow-lake infillings indicates that most of the changes occurred in response to climate changes.

  18. Dissolved Pesticide and Organic Carbon Concentrations Detected in Surface Waters, Northern Central Valley, California, 2001-2002

    USGS Publications Warehouse

    Orlando, James L.; Jacobson, Lisa A.; Kuivila, Kathryn

    2004-01-01

    Field and laboratory studies were conducted to determine the effects of pesticide mixtures on Chinook salmon under various environmental conditions in surface waters of the northern Central Valley of California. This project was a collaborative effort between the U.S. Geological Survey (USGS) and the University of California. The project focused on understanding the environmental factors that influence the toxicity of pesticides to juvenile salmon and their prey. During the periods January through March 2001 and January through May 2002, water samples were collected at eight surface water sites in the northern Central Valley of California and analyzed by the USGS for dissolved pesticide and dissolved organic carbon concentrations. Water samples were also collected by the USGS at the same sites for aquatic toxicity testing by the Aquatic Toxicity Laboratory at the University of California Davis; however, presentation of the results of these toxicity tests is beyond the scope of this report. Samples were collected to characterize dissolved pesticide and dissolved organic carbon concentrations, and aquatic toxicity, associated with winter storm runoff concurrent with winter run Chinook salmon out-migration. Sites were selected that represented the primary habitat of juvenile Chinook salmon and included major tributaries within the Sacramento and San Joaquin River Basins and the Sacramento?San Joaquin Delta. Water samples were collected daily for a period of seven days during two winter storm events in each year. Additional samples were collected weekly during January through April or May in both years. Concentrations of 31 currently used pesticides were measured in filtered water samples using solid-phase extraction and gas chromatography-mass spectrometry at the U.S. Geological Survey's organic chemistry laboratory in Sacramento, California. Dissolved organic carbon concentrations were analyzed in filtered water samples using a Shimadzu TOC-5000A total organic carbon

  19. Isotopic composition in precipitation and groundwater in the northern mountainous region of the Central Valley of Costa Rica.

    PubMed

    Sánchez-Murillo, Ricardo; Esquivel-Hernández, Germain; Sáenz-Rosales, Oscar; Piedra-Marín, Gilberto; Fonseca-Sánchez, Alicia; Madrigal-Solís, Helga; Ulloa-Chaverri, Franz; Rojas-Jiménez, Luis D; Vargas-Víquez, José A

    2017-03-01

    The linkage between precipitation and recharge is still poorly understood in the Central America region. This study focuses on stable isotopic composition in precipitation and groundwater in the northern mountainous region of the Central Valley of Costa Rica. During the dry season, rainfall samples corresponded to enriched events with high deuterium excess. By mid-May, the Intertropical Convergence Zone poses over Costa Rica resulting in a depletion of (18)O/(16)O and (2)H/H ratios. A parsimonious four-variable regression model (r(2 )= 0.52) was able to predict daily δ(18)O in precipitation. Air mass back trajectories indicated a combination of Caribbean Sea and Pacific Ocean sources, which is clearly depicted in groundwater isoscape. Aquifers relying on Pacific-originated recharge exhibited a more depleted pattern, whereas recharge areas relying on Caribbean parental moisture showed an enrichment trend. These results can be used to enhance modelling efforts in Central America where scarcity of long-term data limits water resources management plans.

  20. Alkaline Basalts of The Quaternary Buffalo Valley Volcanic Field, NW Fish Creek Mountains, North-central Nevada, Great Basin

    NASA Astrophysics Data System (ADS)

    Cousens, B.; Henry, C. D.

    2008-12-01

    The Buffalo Valley volcanic field, 5 km southwest of Battle Mountain, consists of approximately 11 cinder cones and associated flows. Youthful volcanoes are rare in the region, and thus this field offers the opportunity to investigate mantle sources currently beneath the central Great Basin. Most of the eruptive centers are distributed along the northwestern margin of the Fish Creek Mountains, a mid-Tertiary caldera complex, along a 13-km-long northeasterly trend that is perpendicular to the regional stress field (or GPS velocity field), suggesting fault control or eruption from a now-buried fissure. The cones are geomorphologically youthful, with well-defined, commonly breached craters. At least one cone, situated slightly east of the main trend, consists of only a thin mantle of scoria and bombs overlying grey Paleozoic limestone. Previous K-Ar and Ar-Ar dating indicate that the cones are between 1.29 and 0.95 Ma in age. Two other nearby Quaternary volcanic centers lie northeast of the Fish Creek Mountains (K-Ar date of 3.3 Ma) and in the center of the Fish Creek caldera (age unknown). Rare Tertiary basalts and more common Tertiary andesites lie around the margin of the caldera. Lavas from the Buffalo Valley cones have vesicular flow tops and more massive interiors. All Quaternary centers are similar petrographically, including 1-2% olivine phenocrysts and megacrysts up to 1 cm in size, and characteristic plagioclase megacrysts that are rarely up to 4 cm long, commonly in a glassy matrix. Two cone samples are alkalic basalt and tephrite with Mg numbers of 0.55, high TiO2 (2.4%), K2O (2.0%), light REE, Nb (60 ppm), but low Cr and Ni (80 ppm), Pb (2 ppm), Ba (450 ppm) and 87Sr/86Sr (0.70375) compared to Late Pliocene/Quaternary volcanic rocks from the western Great Basin near Reno/Carson City/Fallon. The Buffalo Valley cones are similar chemically to lavas from the Pliocene-Quaternary Lunar Craters volcanic field in central Nevada, and are melts of mantle that is

  1. Potential ecological and economic consequences of climate-driven agricultural and silvicultural transformations in central Siberia

    NASA Astrophysics Data System (ADS)

    Tchebakova, Nadezhda M.; Zander, Evgeniya V.; Pyzhev, Anton I.; Parfenova, Elena I.; Soja, Amber J.

    2014-05-01

    Increased warming predicted from general circulation models (GCMs) by the end of the century is expected to dramatically impact Siberian forests. Both natural climate-change-caused disturbance (weather, wildfire, infestation) and anthropogenic disturbance (legal/illegal logging) has increased, and their impact on Siberian boreal forest has been mounting over the last three decades. The Siberian BioClimatic Model (SiBCliM) was used to simulate Siberian forests, and the resultant maps show a severely decreased forest that has shifted northwards and a changed composition. Predicted dryer climates would enhance the risks of high fire danger and thawing permafrost, both of which challenge contemporary ecosystems. Our current goal is to evaluate the ecological and economic consequences of climate warming, to optimise economic loss/gain effects in forestry versus agriculture, to question the relative economic value of supporting forestry, agriculture or a mixed agro-forestry at the southern forest border in central Siberia predicted to undergo the most noticeable landcover and landuse changes. We developed and used forest and agricultural bioclimatic models to predict forest shifts; novel tree species and their climatypes are introduced in a warmer climate and/or potential novel agriculture are introduced with a potential variety of crops by the end of the century. We applied two strategies to estimate climate change effects, motivated by forest disturbance. One is a genetic means of assisting trees and forests to be harmonized with a changing climate by developing management strategies for seed transfer to locations that are best ecologically suited to the genotypes in future climates. The second strategy is the establishment of agricultural lands in new forest-steppe and steppe habitats, because the forests would retreat northwards. Currently, food, forage, and biofuel crops primarily reside in the steppe and forest-steppe zones which are known to have favorable

  2. "Nuestro camino es más largo" (Our Journey Is Much Longer): A "Testimonio" of Immigrant Life in the Central Valley and the Road towards the Professoriate

    ERIC Educational Resources Information Center

    Jiménez, Rosa M.

    2016-01-01

    Throughout my life I have come home to Modesto, California more times than my heart can remember; it is my heart that remembers and keeps my hometown ever present. Today, I am an Assistant Professor at the University of San Francisco. Yet, who I am today is profoundly intertwined with the little girl who grew up in the Central Valley as a daughter…

  3. The central role of agricultural water-use productivity in sustainable water management (Invited)

    NASA Astrophysics Data System (ADS)

    Gleick, P. H.

    2013-12-01

    As global and regional populations continue to rise for the next several decades, the need to grow more food will worsen old -- and produce new -- challenges for water resources. Expansion of irrigated agriculture is slowing due to constraints on land and water, and as a result, some have argued that future new food demands will only be met through improvements in agricultural productivity on existing irrigated and rainfed cropland, reductions in field losses and food waste, and social changes such as dietary preferences. This talk will address the central role that improvements in water-use productivity can play in the food/water/population nexus. In particular, the ability to grow more food with less water will have a great influence on whether future food demands will be met successfully. Such improvements can come about through changes in technology, regulatory systems, economic incentives and disincentives, and education of water users. Example of potential savings from three different strategies to improve agricultural water productivity in California. (From Pacific Institute).

  4. Land use and stream nitrogen concentrations in agricultural watersheds along the central coast of California.

    PubMed

    Los Huertos, M; Gentry, L E; Shennan, C

    2001-11-22

    In coastal California nitrogen (N) in runoff from urban and agricultural land is suspected to impair surface water quality of creeks and rivers that discharge into the Monterey Bay Sanctuary. However, quantitative data on the impacts of land use activities on water quality are largely limited to unpublished reports and do not estimate N loading. We report on spatial and temporal patterns of N concentrations for several coastal creeks and rivers in central California. During the 2001 water year, we estimated that the Pajaro River at Chittenden exported 302.4 Mg of total N. Nitrate-N concentrations were typically <1 mg N l(-1) in grazing lands, oak woodlands, and forests, but increased to a range of 1 to 20 mg N l(-1) as surface waters passed through agricultural lands. Very high concentrations of nitrate (in excess of 80 mg N l(-1)) were found in selected agricultural ditches that received drainage from tiles (buried perforated pipes). Nitrate concentrations in these ditches remained high throughout the winter and spring, indicating nitrate was not being flushed out of the soil profile. We believe unused N fertilizer has accumulated in the shallow groundwater through many cropping cycles. Results are being used to organize landowners, resource managers, and growers to develop voluntary monitoring and water quality protection plans.

  5. The influence of mistletoes on birds in an agricultural landscape of central Mexico

    NASA Astrophysics Data System (ADS)

    Zuria, Iriana; Castellanos, Ignacio; Gates, J. Edward

    2014-11-01

    Mistletoes are hemiparasitic flowering plants that function as keystone resources in forests and woodlands of temperate regions, where a positive relationship between mistletoe density and avian species richness has been observed. Mistletoes have been less studied in tropical regions and the relationship between birds and mistletoes has seldom been explored in tropical agricultural systems. Therefore, we studied the presence of infected trees and infection prevalence (i.e., number of parasitized trees/total number of trees) by Psittacanthus (Loranthaceae) mistletoes in 23 hedgerows located in an agricultural landscape of central Mexico during the dry and rainy seasons, and investigated the relationship between bird species richness and abundance and the abundance of mistletoes. We found a mean of 74 mistletoe plants per 100-m transect of only one species, Psittacanthus calyculatus. Thirty-one percent of the trees surveyed were infected and tree species differed in infection prevalence, mesquite (Prosopis laevigata) being the most infected species with 86% of the surveyed trees infected. For both seasons, we found a positive and significant association between bird species richness and number of mistletoe plants. The same pattern was observed for total bird abundance. Many resident and Neotropical migratory birds were observed foraging on mistletoes. Our results show that mistletoes are important in promoting a higher bird species richness and abundance in tropical agricultural landscapes.

  6. Water-Quality Assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas--Surface-Water Quality, Shallow Ground-Water Quality, and Factors Affecting Water Quality in the Rincon Valley, South-Central New Mexico, 1994-95

    USGS Publications Warehouse

    Anderholm, Scott K.

    2002-01-01

    As part of the National Water-Quality Assessment Program, surface-water and ground-water samples were collected in 1994 and 1995 for analysis of common constituents, nutrients, dissolved organic carbon, trace elements, radioactivity, volatile organic compounds, and pesticides to characterize surface- water quality and shallow ground-water quality and to determine factors affecting water quality in the Rincon Valley, south-central New Mexico. Samples of surface water were collected from three sites on the Rio Grande and from sites on three agricultural drains in the Rincon Valley in January 1994 and 1995, April 1994, and October 1994. Ground-water samples were collected in late April and early May 1994 from 30 shallow wells that were installed during the investigation. Dissolved-solids concentrations in surface water ranged from 434 to 1,510 milligrams per liter (mg/L). Dissolved-solids concentrations were smallest in water from the Rio Grande below Caballo Dam and largest in the drains. Nitrite plus nitrate concentrations ranged from less than 0.05 to 3.3 mg/L as nitrogen, and ammonia concentrations ranged from less than 0.015 to 0.33 mg/L as nitrogen in surface-water samples. Trace-element concentrations in surface water were significantly smaller than the acute-fisheries standards. One or more pesticides were detected in 34 of 37 surface-water samples. DCPA (dacthal) and metolachlor were the most commonly detected pesticides. No standards have been established for the pesticides analyzed for in this study. Dissolved-solids concentrations in shallow ground water ranged from 481 to 3,630 mg/L. All but 2 of 30 samples exceeded the secondary maximum contaminant level for dissolved solids of 500 mg/L. Water from about 73 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for sulfate, and water from about 7 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for chloride. Nitrite plus nitrate

  7. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; shallow ground-water quality of a land-use area in the San Luis Valley, south-central Colorado, 1993

    USGS Publications Warehouse

    Anderholm, S.K.

    1996-01-01

    This report describes the quality of shallow ground water in an agricultural area in the San Luis Valley, Colorado, and discusses how natural and human factors affect the quality of shallow ground water. Thirty-five wells were installed, and water samples were collected from these wells and analyzed for selected dissolved common constituents, nutrients, trace elements, radionuclides, and synthetic organic compounds. The San Luis Valley is a high intermontane valley that is partially drained by the Rio Grande. The San Luis Valley land-use study area was limited to a part of the valley where the depth to water is generally less than 25 feet. The area where the 35 monitor wells were installed was further limited to the part of the study area where center-pivot overhead sprinklers are used to irrigate crops. Precipitation, runoff from adjacent mountainous areas, and ground-water inflow from the adjacent mountainous areas are the main sources of water to the aquifers in the San Luis Valley. Discharge of water from the shallow, unconfined aquifer in the valley is mainly from evapotranspiration. The dominant land use in the San Luis Valley is agriculture, although nonirrigated land and residential land are interspersed with agricultural land. Alfalfa, native hay, barley, wheat, potatoes, and other vegetables are the main crops. Dissolved-solids concentrations in shallow ground water sampled ranged from 75 to 1,960 milligrams per liter. The largest median concentration of cations was for calcium, and the largest median concentration of anions was for bicarbonate in shallow ground water in the San Luis Valley. Calcium concentrations ranged from 7.5 to 300 milligrams per liter, and bicarbonate concentrations ranged from 28 to 451 milligrams per liter. Nitrite plus nitrate concentrations ranged from less than 0.1 to 58 milligrams per liter as N; water from 11 wells had nitrite plus nitrate concentrations greater than 10 milligrams per liter as N. With the exception of the

  8. Scenario earthquake hazards for the Long Valley Caldera-Mono Lake area, east-central California

    USGS Publications Warehouse

    Chen, Rui; Branum, David M.; Wills, Chris J.; Hill, David P.

    2014-01-01

    As part of the U.S. Geological Survey’s (USGS) multi-hazards project in the Long Valley Caldera-Mono Lake area, the California Geological Survey (CGS) developed several earthquake scenarios and evaluated potential seismic hazards, including ground shaking, surface fault rupture, liquefaction, and landslide hazards associated with these earthquake scenarios. The results of these analyses can be useful in estimating the extent of potential damage and economic losses because of potential earthquakes and in preparing emergency response plans. The Long Valley Caldera-Mono Lake area has numerous active faults. Five of these faults or fault zones are considered capable of producing magnitude ≥6.7 earthquakes according to the Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) developed by the 2007 Working Group of California Earthquake Probabilities (WGCEP) and the USGS National Seismic Hazard Mapping (NSHM) Program. These five faults are the Fish Slough, Hartley Springs, Hilton Creek, Mono Lake, and Round Valley Faults. CGS developed earthquake scenarios for these five faults in the study area and for the White Mountains Fault to the east of the study area. Earthquake scenarios are intended to depict the potential consequences of significant earthquakes. They are not necessarily the largest or most damaging earthquakes possible. Earthquake scenarios are both large enough and likely enough that emergency planners should consider them in regional emergency response plans. Earthquake scenarios presented here are based on fault geometry and activity data developed by the WGCEP, and are consistent with the 2008 Update of the United States National Seismic Hazard Maps (NSHM).For the Hilton Creek Fault, two alternative scenarios were developed in addition to the NSHM scenario to account for different opinions in how far north the fault extends into the Long Valley Caldera. For each scenario, ground motions were calculated using the current standard practice

  9. Issues of sustainable irrigated agriculture in the San Joaquin Valley of California in a changing regulatory environment concerning water quality and protection of wildlife

    SciTech Connect

    Quinn, N.W.T.; Delamore, M.L.

    1994-06-01

    Since the discovery of selenium toxicosis in the Kesterson Reservoir in the San Joaquin Valley, California, public perception of irrigated agriculture as a benign competitor for California`s developed water supply has been changed irrevocably. Subsurface return flows from irrigated agriculture were implicated as the source of selenium which led to incidents of reproductive failure in waterfowl and threatened survival of other fish and wildlife species. Stringent water quality objectives were promulgated to protect rivers, tributaries, sloughs and other water bodies receiving agricultural discharges from selenium contamination. Achieving these objectives was left to the agricultural water districts, federal and state agencies responsible for drainage and water quality enforcement in the San Joaquin Basin. This paper describes some of the strategies to improve management of water resources and water quality in response to these new environmental objectives. Similar environmental objectives will likely be adopted by other developed and developing countries with large regions of arid zone agriculture and susceptible wildlife resources. A series of simulation models have been developed over the past four years to evaluate regional drainage management strategies such as: irrigation source control; drainage recycling; selective retirement of agricultural land; regional shallow ground water pumping; coordination of agricultural drainage, wetland and reservoir releases; and short-term ponding of drainage water. A new generation of Geographic Information Service-based software is under development to bridge the gap between planning and program implementation. Use of the decision support system will allow water districts and regulators to continuously monitor drainage discharges to the San Joaquin River in real-time and to assess impacts of management strategies that have been implemented to take advantage of the River`s assimilative capacity for trace elements and salts.

  10. Agricultural Workers in Central California. Volume 1: In 1989; Volume 2: Phase II, 1990-91. California Agricultural Studies, 90-8 and 91-5.

    ERIC Educational Resources Information Center

    Alvarado, Andrew J.; And Others

    Two surveys developed profiles of seasonal agricultural workers and their working conditions in central California. In 1989, a random sample of 347 seasonal workers was interviewed. The sample was 30 percent female and 87 percent Mexican-born. Average age was 35 years and average educational attainment was 5.9 years. Most had parents, spouses, or…

  11. The effects of mountaintop mines and valley fills on the physicochemical quality of stream ecosystems in the central Appalachians: a review.

    PubMed

    Griffith, Michael B; Norton, Susan B; Alexander, Laurie C; Pollard, Amina I; LeDuc, Stephen D

    2012-02-15

    This review assesses the state of the science on the effects of mountaintop mines and valley fills (MTM-VF) on the physicochemical characteristics of streams in the central Appalachian coalfields of West Virginia, Kentucky, Virginia and Tennessee, USA. We focus on the impacts of mountaintop removal coal mining, which involves removing all - or some portion - of the top of a mountain or ridge to expose and mine one or more coal seams. Excess overburden is disposed in constructed fills in small valleys adjacent to the mining site. MTM-VF leachate persistently increases the downstream concentrations of major ions. Conductivity is a coarse measure of these ions, which are dominated by a distinct mixture of SO(4)(2-), HCO(3)(-), Ca(2+) and Mg(2+), that reflects their source, the oxidation of pyrite to form acid followed by neutralization of the acidity by carbonate minerals within the valley fills. This results in neutral to alkaline pHs, a range at which many metals are relatively insoluble. Other compounds within coal or overburden are solubilized and occur at elevated albeit lower concentrations, including K(+), Na(+), Cl(-), Se and Mn. In terms of physical characteristics, the valley fills act like headwater aquifers, baseflows increase in streams below valley fills and water temperatures exhibit reduced seasonal variation. Peak discharges may be increased in response to intense precipitation events, because of compaction of base surfaces of the MTM-VF areas, but newer approaches to reclamation reduce this compaction and may ameliorate these peak flows. Although the sedimentation pond is intended to capture fine particles that wash downstream from the valley fill, some studies found increased fine sediments in streams downstream from valley fills. However, a proportion of these fines may be eroded from stream banks rather than the valley fills. This is probably a result of the alterations in stream flows.

  12. Spatial variability of ammonia and methane dairy emissions in the Central Valley, California with open-path mobile measurements during NASA DISCOVER-AQ 2013

    NASA Astrophysics Data System (ADS)

    Miller, D. J.; Sun, K.; Tao, L.; Zondlo, M. A.

    2013-12-01

    Atmospheric ammonia (NH3) is an important fine aerosol gas-phase precursor, with implications for regional air quality and climate change. Atmospheric methane (CH4) is an important greenhouse gas, with high uncertainties in the partitioning of various emission sources. Ammonia and methane agricultural emissions are highly variable in space and time and are highly uncertain, with a lack of widespread, in-situ measurements. We characterize the spatial variability of dairy livestock emissions by performing high resolution (5 Hz), in-situ, on-road mobile measurements of NH3, CH4, CO2, N2O, CO and H2O simultaneously with open-path sensors mounted on a passenger vehicle. This suite of multiple trace gas measurements allows for emission ratio calculations and separation of agricultural, petrochemical and combustion emission signatures. Mobile measurements were performed in the Tulare County dairy farm region (~120 dairy farms sampled downwind) in the Central Valley, California during NASA DISCOVER-AQ in winter 2013. We calculate the ΔNH3/ΔCH4 and ΔNH3/ΔCO2 emission ratios for each dairy farm sampled downwind. Emission plumes from individual farms are isolated based on known dairy farm locations and high resolution (1 km) surface wind field simulations. Background concentrations are subtracted to calculate the emission ratios. We find high spatial variability of ammonia and methane concentrations, with localized maximums of >1 ppmv NH3 downwind of individual dairy farms. The spatial extent of individual farm emission plumes are evaluated for NH3, CH4 and CO2, which all show well-defined enhancements localized to the dairy farms near the roadside (typical sampling proximity of ≤ 50 m). The NH3 concentrations are correlated with the distance from each dairy farm. The observed median concentration within 100 m downwind of the dairy farms is 63 ppbv NH3, with the 95th percentile at 417 ppbv NH3 and decreases to background conditions at ~500 m distance downwind. The

  13. Utilization of geothermal energy in the production of fuel grade ethanol in the San Luis Valley, Colorado

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Walter, K.M.

    1981-10-01

    The San Luis Valley, a high alpine valley in south-central Colorado, is an area of known geothermal activity. The valley is a sparsely populated agricultural area whose principal crops are potatoes, beer barley, and wheat. In the surrounding mountains there are several lumber operations. This combination of a geothermal heat source and a biomass feedstock source makes the valley a candidate area for the production of fermentation ethanol. Therefore, a study was initiated to investigate the engineering, environmental, institutional and economic feasibility of utilizing geothermal energy for the commercial production of 76 to 189 million liters (20 to 50 million gallons) of fuel grade ethanol in the San Luis Valley.

  14. Estimating the Effects of Conversion of Agricultural Land to Urban Land on Deep Percolation of Irrigation Water in the Grand Valley, Western Colorado

    USGS Publications Warehouse

    Mayo, John W.

    2008-01-01

    The conversion of agricultural land to urban residential land is associated with rapid population growth in the Grand Valley of western Colorado. Information regarding the effects of this land-use conversion on deep percolation, irrigation-water application, and associated salt loading to the Colorado River is needed to support water-resource planning and conservation efforts. The Natural Resources Conservation Service (NRCS) assessed deep percolation and estimated salt loading derived from irrigated agricultural lands in the Grand Valley in a 1985 to 2002 monitoring and evaluation study (NRCS M&E). The U.S. Geological Survey (USGS), in cooperation with the Colorado River Salinity Control Forum and the Mesa Conservation District, quantified the current (2005-2006) deep percolation and irrigation-water application characteristics of 1/4-acre residential lots and 5-acre estates, urban parks, and urban orchard grass fields in the Grand Valley, and compared the results to NRCS M&E results from alfalfa-crop sites. In addition, pond seepage from three irrigation-water holding ponds was estimated. Salt loading was estimated for the urban study results and the NRCS M&E results by using standard salt-loading factors. A daily soil-moisture balance calculation technique was used at all urban study irrigated sites. Deep percolation was defined as any water infiltrating below the top 12 inches of soil. Deep percolation occurred when the soil-moisture balance in the first 12 inches of soil exceeded the field capacity for the soil type at each site. Results were reported separately for urban study bluegrass-only sites and for all-vegetation type (bluegrass, native plants, and orchard grass) sites. Deep percolation and irrigation-water application also were estimated for a complete irrigation season at three subdivisions by using mean site data from each subdivision. It was estimated that for the three subdivisions, 37 percent of the developed acreage was irrigated (the balance

  15. Groundwater discharge by evapotranspiration, Dixie Valley, west-central Nevada, March 2009-September 2011

    USGS Publications Warehouse

    Garcia, C. Amanda; Huntington, Jena M; Buto, Susan G.; Moreo, Michael T.; Smith, J. LaRue; Andraski, Brian J.

    2014-01-01

    Mean annual basin-scale ETg totaled about 28 million cubic meters (Mm3) (23,000 acre-feet [acre-ft]), and represents the sum of ETg from all ET units. Annual groundwater ET from vegetated areas totaled about 26 Mm3 (21,000 acre-ft), and was dominated by the moderate-to-dense shrubland ET unit (54 percent), followed by sparse shrubland (37 percent) and grassland (9 percent) ET units. Senesced grasses observed in the northern most areas of the moderate-to-dense ET unit likely confounded the vegetation index and led to an overestimate of ETg for this ET unit. Therefore, mean annual ETg for moderate-to-dense shrubland presented here is likely an upper bound. Annual groundwater ET from the playa ET unit was 2.2 Mm3 (1,800 acre-ft), whereas groundwater ET from the playa lake ET unit was 0–0.1 Mm3 (0–100 acre-ft). Oxygen-18 and deuterium data indicate discharge from the playa center predominantly represents removal of local precipitation-derived recharge. The playa lake estimate, therefore, is considered an upper bound. Mean annual ETg estimates for Dixie Valley are assumed to represent the pre‑development, long-term ETg rates within the study area.

  16. Geophysical studies of large blind thrust, Valley and Ridge province, central Appalachians

    SciTech Connect

    Wilson, T.H.

    1989-03-01

    Possible thrust-sheet geometries in the unexposed Cambrian-Ordovician lithotectonic unit in the Nittany anticlinorium of the Valley and Ridge province in West Virginia are defined through analysis of geophysical data. Calculated gravity for different subsurface interpretations is compared with observed gravity. Comparisons of model calculations to terrain-corrected Bouguer gravity indicate that a large blind thrust of the Cambrian-Ordovician lithotectonic unit, extending across the entire width of the anticlinorium, is an acceptable subsurface interpretation. A seismic line across the anticlinorium is also presented. The seismic line reveals that a large part of the area is underlain by a double thickness of the Cambrian-Ordovician lithotectonic unit. Data can be interpreted many ways. However, the gravity data require that an acceptable model have only minor lateral density contrasts across the anticlinorium so that effectively, a double thickness of the Cambrian Ordovician lithotectonic unit exists across it. Both the gravity and seismic data indicate that the presence of separate horses beneath the major Silurian-Devonian structures exposed at the surface is unlikely. 12 figures.

  17. Socioeconomic effects of power marketing alternatives for the Central Valley and Washoe Projects: 2005 regional econmic impact analysis using IMPLAN

    SciTech Connect

    Anderson, D.M.; Godoy-Kain, P.; Gu, A.Y.; Ulibarri, C.A.

    1996-11-01

    The Western Area Power Administration (Western) was founded by the Department of Energy Organization Act of 1977 to market and transmit federal hydroelectric power in 15 western states outside the Pacific Northwest, which is served by the Bonneville Power Administration. Western is divided into four independent Customer Service Regions including the Sierra Nevada Region (Sierra Nevada), the focus of this report. The Central Valley Project (CVP) and the Washoe Project provide the primary power resources marketed by Sierra Nevada. Sierra Nevada also purchases and markets power generated by the Bonneville Power Administration, Pacific Gas and Electric (PG&E), and various power pools. Sierra Nevada currently markets approximately 1,480 megawatts of power to 77 customers in northern and central California. These customers include investor-owned utilities, public utilities, government agencies, military bases, and irrigation districts. Methods and conclusions from an economic analysis are summarized concerning distributional effects of alternative actions that Sierra Nevada could take with it`s new marketing plan.

  18. Deep-currents along a rift valley of Central Indian Ridge observed by AUV "r2D4"

    NASA Astrophysics Data System (ADS)

    Komaki, K.; Ura, T.; Nagahashi, K.; Tamaki, K.

    2008-12-01

    In December 2006, the Institute of Industrial Science made geological and chemical investigation along rift valleys off the Rodriguez Island in the Central Indian Ridge with an AUV "gr2D4"h and found hydrothermal activities in one of the valleys, named the Great Dodo Lava Plain (water depth of approximately 2700m). In this present study, based on the AUV"fs navigation data taken from the investigation, we figured out the distribution of deep-currents in the Great Dodo Lava Plain and analyzed those currents and their relations with the tidal current and water-mass property. For current velocity, we used water-tracking velocity data measured by the Doppler Velocity Log (DVL) at a layer under the AUV. When the AUV was close to the sea bed, the velocity was adjusted to the absolute current velocity with bottom-tracking velocity measured by the DVL. When the bottom-tracking velocity was not available, the velocity was adjusted with AUV"fs velocity measured by the Inertial Navigation System. The adjusted current velocity data in the Great Dodo Lava Plain were observed for 6.5-hours in the range of 18.32°S-18.45°S, 65.28°E-65.37°E, and most of them reached 20 cm s-1 or more. The direction of the currents is between northwest and northeast, which almost corresponds to the direction of the valley"fs extension (north-northwest). The observed current speed is much higher than the tidal current speed predicted from a barotropic tidal model (< 3 cm s-1), but its meridional velocity component is stronger than the zonal component as well as the observed velocity. The predicted tidal current velocity shows semi-diurnal period, and that is also the case in the observed meridional velocity component. Thus, it is expected that the deep-currents and tidal currents are influenced by the bottom topography extending north-northwestward. For error consideration, we compared near-surface current velocities measured by the AUV and by the shipboard acoustic Doppler velocity profiler of

  19. Geomorphic process and vegetation diversity in the active riverbed and the floodplain in the Kamikochi valley, central Japan

    NASA Astrophysics Data System (ADS)

    Shimazu, H.

    2012-04-01

    The Kamikochi valley is located in a mountainous area in central Japan. The R. Azusa in this valley is a braided river with floodplains. Dense riparian forests cover the floodplains and fragmented small pioneer plant patches and isolated old pioneer trees are distributed in the active riverbed. This study aims to discuss the relationships between geomorphic processes of the river and vegetation diversity. Yearly mapping of the riverbed micro-landforms revealed that channel migrations and landform changes in the active riverbed occurs once every one or several years during a bankfull flood in the rainy season. Germination ages of riparian trees using a dendrochronological technique, their established layers and landform structure were examined to reconstruct floodplain dynamics. Major channel migrations destroyed the riparian forest repeatedly and the recent event occurred about 100 years ago. This caused a longitudinal zonal structure of the riparian forest vegetation, elm-fir forest, mature pioneer forest and young pioneer forests. The young pioneer forest is located alongside the present riverbed. The mature pioneer forest lies between the older elm-fir forests. The pioneer plants germinated simultaneously on the abandoned channel after channel migration. These trees became the mature pioneer forest. Ditches and lobes including boulders are found in the floodplain. The ditches extend parallel to the direction of the present and former channels. The lobes are distributed alongside them. Younger trees under the canopy grow on the lobes in the inner part of the floodplain. These young trees and lobes show that dominant sedimentation process in the floodplain is not lateral flooding, but longitudinal flooding. Sediments from the present channel flew downward through the ditches and were overflowed on the floodplain. This process destroyed the vegetation in and alongside the ditches causing vegetation diversity in the inner part of the riparian forest. Several species

  20. Early agriculture and crop transmission among Bronze Age mobile pastoralists of Central Eurasia

    PubMed Central

    Spengler, Robert; Frachetti, Michael; Doumani, Paula; Rouse, Lynne; Cerasetti, Barbara; Bullion, Elissa; Mar'yashev, Alexei

    2014-01-01

    Archaeological research in Central Eurasia is exposing unprecedented scales of trans-regional interaction and technology transfer between East Asia and southwest Asia deep into the prehistoric past. This article presents a new archaeobotanical analysis from pastoralist campsites in the mountain and desert regions of Central Eurasia that documents the oldest known evidence for domesticated grains and farming among seasonally mobile herders. Carbonized grains from the sites of Tasbas and Begash illustrate the first transmission of southwest Asian and East Asian domesticated grains into the mountains of Inner Asia in the early third millennium BC. By the middle second millennium BC, seasonal camps in the mountains and deserts illustrate that Eurasian herders incorporated the cultivation of millet, wheat, barley and legumes into their subsistence strategy. These findings push back the chronology for domesticated plant use among Central Eurasian pastoralists by approximately 2000 years. Given the geography, chronology and seed morphology of these data, we argue that mobile pastoralists were key agents in the spread of crop repertoires and the transformation of agricultural economies across Asia from the third to the second millennium BC. PMID:24695428

  1. Early agriculture and crop transmission among Bronze Age mobile pastoralists of Central Eurasia.

    PubMed

    Spengler, Robert; Frachetti, Michael; Doumani, Paula; Rouse, Lynne; Cerasetti, Barbara; Bullion, Elissa; Mar'yashev, Alexei

    2014-05-22

    Archaeological research in Central Eurasia is exposing unprecedented scales of trans-regional interaction and technology transfer between East Asia and southwest Asia deep into the prehistoric past. This article presents a new archaeobotanical analysis from pastoralist campsites in the mountain and desert regions of Central Eurasia that documents the oldest known evidence for domesticated grains and farming among seasonally mobile herders. Carbonized grains from the sites of Tasbas and Begash illustrate the first transmission of southwest Asian and East Asian domesticated grains into the mountains of Inner Asia in the early third millennium BC. By the middle second millennium BC, seasonal camps in the mountains and deserts illustrate that Eurasian herders incorporated the cultivation of millet, wheat, barley and legumes into their subsistence strategy. These findings push back the chronology for domesticated plant use among Central Eurasian pastoralists by approximately 2000 years. Given the geography, chronology and seed morphology of these data, we argue that mobile pastoralists were key agents in the spread of crop repertoires and the transformation of agricultural economies across Asia from the third to the second millennium BC.

  2. Predictors of blood lead levels in agricultural villages practicing wastewater irrigation in Central Mexico.

    PubMed

    Cifuentes, E; Villanueva, J; Sanin, L H

    2000-01-01

    To investigate whether the agricultural use of untreated wastewater (i.e. crop irrigation) was associated with elevated blood lead levels in a farming population in the Mezquital Valley and which risk factors, other than exposure to untreated wastewater, were associated with elevated blood lead levels, lead levels were measured in venous blood obtained from 735 individuals. Blood samples were analyzed by atomic absorption spectrophotometry. Food habits and dietary intake were gathered by interview, using a semi-quantitative food-frequency questionnaire. The average blood lead level was 7.8 microg/dL (SD 4.66 microg/dL; range 1.2-36.7 microg/dL). 23% of the study population had blood lead levels exceeding 10 microg/dL. The use of lead-glazed ceramics (LGC) was significantly associated with elevated lead levels (p = < 0.001). Other significant variables included age, gender (males), and non-farming-related occupations (e.g., technicians, factory workers). p = 0.005, 0.08, and 0.001, respectively. When the analysis was stratified by the use of LGC for food preparation, an inverse relationship between higher daily calcium intake and blood lead level was detected (beta = - 0.040, p = < 0.05). Thus, blood lead levels were positively associated with the use of LGC. Calcium intake showed a protective effect, maybe by decreasing absorption of lead in the gastrointestinal tract. No association between occupational exposure to untreated wastewater or crop consumption and blood lead levels was detected. Further environmental and health surveillance is recommended.

  3. Long-Term Impacts on Macroinvertebrates Downstream of Reclaimed Mountaintop Mining Valley Fills in Central Appalachia

    NASA Astrophysics Data System (ADS)

    Pond, Gregory J.; Passmore, Margaret E.; Pointon, Nancy D.; Felbinger, John K.; Walker, Craig A.; Krock, Kelly J. G.; Fulton, Jennifer B.; Nash, Whitney L.

    2014-10-01

    Recent studies have documented adverse effects to biological communities downstream of mountaintop coal mining and valley fills (VF), but few data exist on the longevity of these impacts. We sampled 15 headwater streams with VFs reclaimed 11-33 years prior to 2011 and sampled seven local reference sites that had no VFs. We collected chemical, habitat, and benthic macroinvertebrate data in April 2011; additional chemical samples were collected in September 2011. To assess ecological condition, we compared VF and reference abiotic and biotic data using: (1) ordination to detect multivariate differences, (2) benthic indices (a multimetric index and an observed/expected predictive model) calibrated to state reference conditions to detect impairment, and (3) correlation and regression analysis to detect relationships between biotic and abiotic data. Although VF sites had good instream habitat, nearly 90 % of these streams exhibited biological impairment. VF sites with higher index scores were co-located near unaffected tributaries; we suggest that these tributaries were sources of sensitive taxa as drifting colonists. There were clear losses of expected taxa across most VF sites and two functional feeding groups (% scrapers and %shredders) were significantly altered. Percent VF and forested area were related to biological quality but varied more than individual ions and specific conductance. Within the subset of VF sites, other descriptors (e.g., VF age, site distance from VF, the presence of impoundments, % forest) had no detectable relationships with biological condition. Although these VFs were constructed pursuant to permits and regulatory programs that have as their stated goals that (1) mined land be reclaimed and restored to its original use or a use of higher value, and (2) mining does not cause or contribute to violations of water quality standards, we found sustained ecological damage in headwaters streams draining VFs long after reclamation was completed.

  4. Long-term impacts on macroinvertebrates downstream of reclaimed mountaintop mining valley fills in Central Appalachia.

    PubMed

    Pond, Gregory J; Passmore, Margaret E; Pointon, Nancy D; Felbinger, John K; Walker, Craig A; Krock, Kelly J G; Fulton, Jennifer B; Nash, Whitney L

    2014-10-01

    Recent studies have documented adverse effects to biological communities downstream of mountaintop coal mining and valley fills (VF), but few data exist on the longevity of these impacts. We sampled 15 headwater streams with VFs reclaimed 11-33 years prior to 2011 and sampled seven local reference sites that had no VFs. We collected chemical, habitat, and benthic macroinvertebrate data in April 2011; additional chemical samples were collected in September 2011. To assess ecological condition, we compared VF and reference abiotic and biotic data using: (1) ordination to detect multivariate differences, (2) benthic indices (a multimetric index and an observed/expected predictive model) calibrated to state reference conditions to detect impairment, and (3) correlation and regression analysis to detect relationships between biotic and abiotic data. Although VF sites had good instream habitat, nearly 90 % of these streams exhibited biological impairment. VF sites with higher index scores were co-located near unaffected tributaries; we suggest that these tributaries were sources of sensitive taxa as drifting colonists. There were clear losses of expected taxa across most VF sites and two functional feeding groups (% scrapers and %shredders) were significantly altered. Percent VF and forested area were related to biological quality but varied more than individual ions and specific conductance. Within the subset of VF sites, other descriptors (e.g., VF age, site distance from VF, the presence of impoundments, % forest) had no detectable relationships with biological condition. Although these VFs were constructed pursuant to permits and regulatory programs that have as their stated goals that (1) mined land be reclaimed and restored to its original use or a use of higher value, and (2) mining does not cause or contribute to violations of water quality standards, we found sustained ecological damage in headwaters streams draining VFs long after reclamation was completed.

  5. Regional soil geochemistry in the Ojailen Valley: a realm dominated by the industrial and mining city of Puertollano (South Central Spain)

    NASA Astrophysics Data System (ADS)

    López-Berdonces, Miguel; Fernandez-Calderón, Sergio; Higueras, Pablo; María Esbrí, Jose; Gonzalez-Corrochano, Beatríz; García-Noguero, Eva Mª; Martínez-Coronado, Alba; García-Noguero, Carolina

    2013-04-01

    Regional soil geochemistry in the Ojailén Valley: a realm dominated by the industrial and mining city of Puertollano (South Central Spain). Authors: Miguel A. López-Berdonces¹; Sergio Fernández Calderón¹; Pablo Higueras¹; José María Esbrí¹; Beatriz González-Corrochano¹; Eva Mª García-Noguero¹; Alba Martínez-Coronado¹; Carolina García Noguero¹ ¹Instituto de Geología Aplicada, Universidad de Castilla La Mancha, Almadén 13400 (Spain). Ojailén Valley is situated in South Central of Spain, an area where livestock, agriculture, mining and industry coexist. This work tries to assess the relationships between these activities and local environmental compartments: water, soils and heavy metal contents, and establish the most appropriate methodology of sample treatment and analytical techniques that can be employed on this kind of studies. For soil geochemistry, 152 samples were taken at two different depths, one at surface layer and another at 20 cm depth, and establish relationships between them and the possible sources. For this purpose, we determine soil parameters (pH, conductivity and organic matter) and total metal contents by Energy Dispersion of X Ray Fluorescence (EDXRF). Samples with higher nickel contents were analyzed with Inductive Coupled Plasma Spectroscopy (ICP-OES) after acid digestion. The study of surface waters includes 18 samples along the river and tributaries near mining and industrial areas. Water analysis was performed by ICP-OES. Soil samples shows pH between 6 and 8.5, highest located near on the east part of the valley, in the vicinity of petrochemical complex. Conductivity values show higher levels (1600 µS cm¯¹) in the vicinity of Puertollano and the industrial sites. Local reference value (LRV) for contaminated soils were determined according to the methodology proposed by Jimenez-Ballesta et al. (2010), using the equation: LRV=GM + 2SD, where LRV: Local Reference Value, GM: Geometric Mean, SD: Standard Deviation

  6. Flooding of the Great River during the Common Era: A Paleohydrological Record of High Magnitude Flood Events from the Central Mississippi River Valley

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Munoz, S. E.; Gruley, K. E.; Massie, A.

    2014-12-01

    Streamflow characteristics are known to be sensitive to changes in climate, but few continuous records of flooding exist to evaluate the response of hydrological systems to centennial- and millennia-scale climate changes. Here, we present sedimentary records from two oxbow lakes (Horseshoe Lake and Grassy Lake, Illinois, USA) in the central Mississippi River valley (CMRV) that display abrupt shifts in sediment composition and particle-size consistent with deposition by floodwaters immediately following inundation of the floodplain. The sedimentary record at Horseshoe Lake begins ca. AD 100 and displays five major flood events, with four of these occurring after ca. AD 1100. Situated 200 km downstream, the record from Grassy Lake begins later, ca. AD 800, and also shows four major flood events after ca. AD 1100. An analysis of synchronicity using Bayesian age modelling software shows high likelihoods that the four overlapping flood events occurred at the same time, confirming that these events resulted from flooding of the Mississippi River. The most recent event we record at AD 1840 ± 50 corresponds to the AD 1844 flood, the largest flood by discharge (37 m3/s) measured by the gauging station at St. Louis, Missouri, indicating that our sedimentary records document high magnitude flood events. Together, our two sedimentary records show a major shift in the frequency of high magnitude flooding in the central Mississippi River at ca. AD 1100. From AD 100 - AD 1100, only one relatively subtle flood event is recorded, but from AD 1100 - AD 1900, four high magnitude floods deposited distinctive sediment at both sites. The period of infrequent flooding corresponds to a time of agricultural intensification and population growth in the CMRV, while the entire region was abandoned when flood frequency increased. The pronounced shift in flood frequency we observe in our records at ca. AD 1100 begins during the Medieval Climate Anomaly (MCA; AD 950 - AD 1250), a period of

  7. Solar pacing of storm surges, coastal flooding and agricultural losses in the Central Mediterranean.

    PubMed

    Kaniewski, David; Marriner, Nick; Morhange, Christophe; Faivre, Sanja; Otto, Thierry; Van Campo, Elise

    2016-04-29

    Storm surges, leading to catastrophic coastal flooding, are amongst the most feared natural hazards due to the high population densities and economic importance of littoral areas. Using the Central Mediterranean Sea as a model system, we provide strong evidence for enhanced periods of storminess leading to coastal flooding during the last 4500 years. We show that long-term correlations can be drawn between storminess and solar activity, acting on cycles of around 2200-yr and 230-yr. We also find that phases of increased storms and coastal flooding have impacted upon mid- to late Holocene agricultural activity on the Adriatic coast. Based on the general trend observed during the second half of the 20(th) century, climate models are predicting a weakening of Mediterranean storminess. By contrast, our new data suggest that a decrease in solar activity will increase and intensify the risk of frequent flooding in coastal areas.

  8. Solar pacing of storm surges, coastal flooding and agricultural losses in the Central Mediterranean

    PubMed Central

    Kaniewski, David; Marriner, Nick; Morhange, Christophe; Faivre, Sanja; Otto, Thierry; Van Campo, Elise

    2016-01-01

    Storm surges, leading to catastrophic coastal flooding, are amongst the most feared natural hazards due to the high population densities and economic importance of littoral areas. Using the Central Mediterranean Sea as a model system, we provide strong evidence for enhanced periods of storminess leading to coastal flooding during the last 4500 years. We show that long-term correlations can be drawn between storminess and solar activity, acting on cycles of around 2200-yr and 230-yr. We also find that phases of increased storms and coastal flooding have impacted upon mid- to late Holocene agricultural activity on the Adriatic coast. Based on the general trend observed during the second half of the 20th century, climate models are predicting a weakening of Mediterranean storminess. By contrast, our new data suggest that a decrease in solar activity will increase and intensify the risk of frequent flooding in coastal areas. PMID:27126207

  9. Solar pacing of storm surges, coastal flooding and agricultural losses in the Central Mediterranean

    NASA Astrophysics Data System (ADS)

    Kaniewski, David; Marriner, Nick; Morhange, Christophe; Faivre, Sanja; Otto, Thierry; van Campo, Elise

    2016-04-01

    Storm surges, leading to catastrophic coastal flooding, are amongst the most feared natural hazards due to the high population densities and economic importance of littoral areas. Using the Central Mediterranean Sea as a model system, we provide strong evidence for enhanced periods of storminess leading to coastal flooding during the last 4500 years. We show that long-term correlations can be drawn between storminess and solar activity, acting on cycles of around 2200-yr and 230-yr. We also find that phases of increased storms and coastal flooding have impacted upon mid- to late Holocene agricultural activity on the Adriatic coast. Based on the general trend observed during the second half of the 20th century, climate models are predicting a weakening of Mediterranean storminess. By contrast, our new data suggest that a decrease in solar activity will increase and intensify the risk of frequent flooding in coastal areas.

  10. Evidence for Groundwater Contamination Vulnerability in California?s Central Valley

    SciTech Connect

    Moran, J E; Leif, R; Esser, B K; Singleton, M J

    2005-12-13

    The California Water Resources Control Board, in collaboration with the US Geological Survey and Lawrence Livermore National Laboratory, has implemented a program to assess the susceptibility of groundwater resources. Advanced techniques such as groundwater age dating using the tritium-helium method, extensive use of oxygen isotopes of the water molecule ({delta}{sup 18}O) for recharge water provenance, and analysis of common volatile organic compounds (VOCs) at ultra-low levels are applied with the goal of assessing the contamination vulnerability of deep aquifers, which are frequently used for public drinking water supply. Over 1200 public drinking water wells have been tested to date, resulting in a very large, tightly spaced collection of groundwater ages in some of the heavily exploited groundwater basins of California. Smaller scale field studies that include shallow monitoring wells are aimed at assessing the probability that nitrate will be transported to deep drinking water aquifers. When employed on a basin-scale, groundwater ages are an effective tool for identifying recharge areas, defining flowpaths, and determining the rate of transport of water and entrained contaminants. De-convolution of mixed ages, using ancillary dissolved noble gas data, gives insight into the water age distribution drawn at a well, and into the effective dilution of contaminants such as nitrate at long-screened production wells. In combination with groundwater ages, low-level VOCs are used to assess the impact of vertical transport. Special studies are focused on the fate and transport of nitrate with respect to vulnerability of aquifers in agricultural and formerly agricultural areas.

  11. First report on organochlorine pesticides in water in a highly productive agro-industrial basin of the Central Valley, Chile.

    PubMed

    Montory, Monica; Ferrer, Javier; Rivera, Diego; Villouta, María Valentina; Grimalt, Joan O

    2017-05-01

    The Ñuble River flows through an agricultural area in the central zone of Chile in which different types of fruits are grown. The objective of this study was to identify the levels and source of organochlorine pesticides (OCPs) in the surface waters of the Ñuble River. Surface water samples were collected at 10 sampling points and analyzed for 19 organochlorine pesticides during the dry (spring-summer) and wet (autumn-winter) periods of 2013 and 2014. The results revealed that concentrations of total OCPs in surface waters ranged from 0.12 to 26.28 ng/l. Endosulfan and lindane were the main OCPs in the water. The maximum OCP levels were found in the dry period, while significantly lower concentrations were recorded in the wet period. This indicates that patterns of OCPs have varied in the last 10 years as this study found low concentrations of DDT and metabolites but significantly increased concentrations of α-endosulfan. Given the fact that OCPs were withdrawn from agricultural used many years ago, their presence indicates that they may be still in use clandestinely. Findings of significant concentrations of endosulfan and lindane in this study lead to the conclusion that the chemical fallow practices contribute to runoff into the river and surface water infiltration into groundwater. Because no studies have previously measured OCP levels in agricultural basins in Chile, this study is an important contribution to the knowledge of organochlorine contaminants present in surface water in Chile.

  12. SEASONAL VARIATION IN PESTICIDE LOADS AND TRENDS IN THE CENTRAL VALLEY, CALIFORNIA: CALCULATED USING TWO PARAMETRIC METHODS

    NASA Astrophysics Data System (ADS)

    Saleh, D.; Domagalski, J. L.; Johnson, H. M.; Lorenz, D. J.

    2009-12-01

    Mass loading and trends in concentration were calculated for four pesticides in two watersheds with different land uses in the Central Valley, California, by using two parametric models: (1) the Seasonal Wave model (SeaWave), in which a pulse signal is used to describe the annual cycle of pesticide occurrence in a stream; and, (2) the Sine Wave model (SineWave), in which first-order Fourier series sine and cosine terms are used to simulate seasonal loading patterns. The models were applied to data for water years 1997 through 2005 provided by the National Water Quality Assessment Program (NAWQA). The pesticides considered in this study were carbaryl, diazinon, metolachlor, and molinate. Data were analyzed for two seasons: precipitation season (October through March), and the irrigation season (April through September). Results from the two models show that the ability to capture seasonal variations in pesticide concentrations was affected by pesticide use patterns and the methods by which pesticides are transported to streams. When compared with results from previous studies, both models well estimated seasonal loads and trends in concentrations. It is important to point out that loads estimated by the two models did not differ substantially from each other, with the exceptions of carbaryl and molinate during the precipitation season, where loads were affected by application patterns and precipitation. At the same time, trends in pesticide concentrations over time, as estimated by both models, were nearly identical indicating that either model can be used equally for calculating trends in concentrations. However, in watersheds where pesticides are applied in specific patterns— involving multiple applications of various amounts—the SeaWave model might be a better model to use due to its robust capability to describe seasonal variations in pesticide concentrations. As a case study, trends in pesticide concentrations for streams in the Central Valley were

  13. Crustal imaging using old industry seismic reflection data across the Coast Ranges and the Great Valley in Central Californa, USA

    NASA Astrophysics Data System (ADS)

    Gutjahr, Stine; Buske, Stefan

    2014-05-01

    We make use of the old industry seismic reflection data set SJ-6 in order to image middle and lower crustal structures beneath the California Coast Ranges and the Great Valley in Central California. For this purpose we use advanced imaging techniques in combination with a local 3D tomographic velocity model in order to map the reflectivity structure of the crust in particular across the San Andreas fault zone. The SJ-6 data set is so far the only active seismic data set crossing the San Andreas fault where the transitional fault segment approaches into the locked segment that last ruptured during the 1857 M7.9 Fort Tejon earthquake. This particular region shows major non volcanic tremor activity that is related directly to and at close range to the deep San Andreas fault zone. The SJ-6 data have been recorded along a crooked profile line that changes its predominating orientation from SW-NE to W-E after crossing the San Andreas fault surface trace. For this reason the imaging technique is implemented in 3D in order to account for the true source and receiver locations. We use a Prestack Kirchhoff type migration method called Fresnel Volume migration that spatializes the recorded reflection energy to the vicinity of the actual reflector elements according to the subsurface model. The results are high quality seismic images of improved signal- to noise ratio compared to standard Prestack Kirchhoff migration techniques. In order to extract reflection signals recorded from the deep crust we extend the record length of the data by adding zeros to the original field data and then crosscorrelate the latter with the source sweep signal. Several adjustments are applied to the migration and stacking schemes in order to obtain final 2D depth sections that represent the reflectivity structure directly beneath the crooked acquisition line. The most prominent feature southwest of the San Andreas fault is a bundle of strong northeast dipping reflectors within the lower crust of

  14. Diagenesis of quartz in the Upper Proterozoic Kaimur Sandstones, Son Valley, central India

    NASA Astrophysics Data System (ADS)

    Morad, S.; Bhattacharyya, Ajit; Al-Aasm, I. S.; Ramseyer, K.

    1991-10-01

    The Upper Proterozoic Kaimur Sandstones in central India are quartz-, sublithic- and lithic-arenites cemented by quartz, illite and hematite. Diagenetic quartz occurs in five modes: syntaxial overgrowths, fracture healings, aggregates of small euhedral crystals, quartz resulting from the alteration of detrital silicates and from the recrystallization of quartz. Intergranular pressure dissolution is suggested as the main source of silica with smaller contribution from other sources, such as silica dissolved in meteoric waters, stylolitization, clay-mineral diagenesis, and the alteration of detrital silicates. Studies on the fluid inclusions and oxygen isotopes of diagenetic quartz suggest that meteoric water modified by diagenetic reactions has mediated the quartz cementation.

  15. A new subdivision of the central Sesia Zone (Aosta Valley, Italy)

    NASA Astrophysics Data System (ADS)

    Giuntoli, Francesco; Engi, Martin; Manzotti, Paola; Ballèvre, Michel

    2015-04-01

    The Sesia Zone in the Western Alps is a continental terrane probably derived from the NW-Adriatic margin and polydeformed at HP conditions during Alpine convergence. Subdivisions of the Sesia Zone classically have been based on the dominant lithotypes: Eclogitic Micaschist Complex, Seconda Zona Diorito-Kinzigitica, and Gneiss Minuti Complex. However, recent work (Regis et al., 2014) on what was considered a single internal unit has revealed that it comprises two or more tectonic slices that experienced substantially different PTDt-evolutions. Therefore, detailed regional petrographic and structural mapping (1:3k to 1:10k) was undertaken and combined with extensive sampling for petrochronological analysis. Results allow us to propose a first tectonic scheme for the Sesia Zone between the Aosta Valley and Val d'Ayas. A set of field criteria was developed and applied, aiming to recognize and delimit the first order tectonic units in this complex structural and metamorphic context. The approach rests on three criteria used in the field: (1) Discontinuously visible metasedimentary trails (mostly carbonates) considered to be monocyclic (Permo-Mesozoic protoliths); (2) mappable high-strain zones; and (3) visible differences in the metamorphic imprint. None of these key features used are sufficient by themselves, but in combination they allow us to propose a new map that delimits main units. We propose an Internal Complex with three eclogitic sheets, each 0.5-3 km thick. Dominant lithotypes include micaschists associated with mafic rocks and minor orthogneiss. The main foliation is of HP, dipping moderately NW. Each of these sheets is bounded by (most likely monometamorphic) sediments, <10-50 m thick. HP-relics (of eclogite facies) are widespread, but a greenschist facies overprint locally is strong close to the tectonic contact to neighbouring sheets. An Intermediate Complex lies NW of the Internal Complex and comprises two thinner, wedge-shaped units termed slices. These

  16. Estimation of a water budget for 1972-2000 for the Grasslands Area, central part of the Western San Joaquin Valley, California

    USGS Publications Warehouse

    Brush, Charles F.; Belitz, Kenneth; Phillips, Steven P.

    2004-01-01

    Equitable implementation of regulations restricting discharges from agricultural drains into the San Joaquin River requires a greater understanding of the influence of extreme precipitation events on the ground-water flow system. As part of a larger investigation, this study estimated ground-water recharge and ground-water pumpage, two important components of the water budget in the Grasslands drainage area in the central part of the western San Joaquin Valley, California, for the water years 1972 through 2000. These estimates will be used as inputs to a numerical simulation model of the regional ground-water flow system in the continuing investigation. Crop-acreage and surface-water delivery data were compiled for 14 water districts and 6 other areas comprising approximately 97 percent of the 600-square-mile study area. Little ground-water pumpage data exists for the study area. A climate-based approach was employed to estimate annual water-table recharge flux and ground-water pumpage for 11 water-budget areas. Ground-water pumpage was estimated from the residual irrigation demand after crop consumption of surface water. Estimated recharge flux to the water table for the entire study area averaged 0.8 ft/yr, and estimated ground-water pumpage per unit area for the entire study area averaged 0.5 ft/yr. Increased discharges from agricultural drains in the late 1990s may have been due partly to 4 years of high recharge from precipitation over the 6-year period from 1993 to 1998. Knowledge of the ratio of annual crop water demand to annual potential evapotranspiration, expressed as an aggregate crop coefficient, Kd, will facilitate estimation of annual water-budget components in future studies. Annual aggregate crop coefficients, calculated each year for the entire study area, were nearly constant at 0.59 from 1983 to 2000, and reasonably constant at 0.53 prior to 1983. The overall trend suggests continuous reductions in recharge from irrigation over time. This

  17. Late Quaternary environments and prehistoric occupation in the lower White Nile valley, central Sudan

    NASA Astrophysics Data System (ADS)

    Williams, Martin A. J.; Usai, Donatella; Salvatori, Sandro; Williams, Frances M.; Zerboni, Andrea; Maritan, Lara; Linseele, Veerle

    2015-12-01

    Despite the major contributions provided over fifty years ago by A.J. Arkell and J.D. Tothill to our understanding of late Quaternary environments and prehistoric occupation near the confluence of the Blue and White Nile in central Sudan, three key questions have remained unresolved since then. (a) Was the decline in Nile flood levels from early Holocene times onwards caused by a reduction in Nile discharge, or by channel incision, or both? (b) Was the regional climate wetter during times of high Nile floods and drier during times of low Nile floods? (c) Given the high degree of disturbance of Mesolithic and later prehistoric sites, is it possible to identify primary-context, stratified and undisturbed occupation? Drawing upon dated evidence from three sites to the east of and three to the west of the lower White Nile, we provide a qualified answer to the first question and documented affirmative answers to the second and third questions.

  18. Modelling air quality impact of a biomass energy power plant in a mountain valley in Central Italy

    NASA Astrophysics Data System (ADS)

    Curci, Gabriele; Cinque, Giovanni; Tuccella, Paolo; Visconti, Guido; Verdecchia, Marco; Iarlori, Marco; Rizi, Vincenzo

    2012-12-01

    In this study, we investigate the potential impact on local air quality of a biomass power plant, which is planned for installation near L'Aquila, a city of 70,000 people located in a mountain valley in Central Italy. The assessment is carried out by applying a one year simulation with the CALPUFF model, following the recommendations of the U. S. Environmental Protection Agency. Meteorological input is produced with CALMET model, fed with both MM5 meteorological fields at 3 km resolution and wind observations from a surface weather station. We estimate small (<0.5 μg m-3) annual average increments to SO2, NO2 and PM10 ambient levels over the domain of interest, but significant (up to 50% for NO2) enhancements and several violations (up to 141 for NO2) of hourly limits for human protection within 1.5 km from the source. These results anticipate a larger negative effect on local air quality than those published by the building firm of the plant. We also suggest that a minimum distance of 5 km from the nearest residential area would represent a significant decrease of population exposure.

  19. Magnetic Susceptibility and Mineral Zonations Controlled by Provenance in Loess along the Illinois and Central Mississippi River Valleys

    USGS Publications Warehouse

    Grimley, D.A.; Follmer, L.R.; McKay, E.D.

    1998-01-01

    Magnetic susceptibility (MS) patterns have proven useful for regional stratigraphic correlations of zones within thick, oxidized Peoria and Roxana Silts along the Illinois and Central Mississippi River valleys for more than 350 km. Variations in MS of C horizon loess are controlled by silt-sized magnetite content and are interpreted to reflect changes in sediment provenance due to fluctuations of the Superior and Lake Michigan glacier lobes and the diversion of the Mississippi River to its present course. Grain size distributions and scanning electron microscopic observations indicate that stratigraphic changes in MS are not significantly influenced by eolian sorting or diagenetic dissolution, respectively. Three compositional zones (lower, middle, and upper) are delineated within Peoria Silt which usually can be traced in the field by MS, the occurrence of clay beds, interstadial soils, and/or subtle color changes. These zones can be correlated with, but are generally of more practical use than, previously studied dolomite zones (McKay, 1977) or clay mineral zones (Frye et al., 1968). However, mineralogical analyses can help to substantiate zone boundaries when in question. MS and compositional zones may indirectly record a climatic signal, primarily through the effect that global cooling has had on ice lobe fluctuations in the Upper Mississippi drainage basin. ?? 1998 University of Washington.

  20. Genetic analysis of 17 Y-STRs in a Mestizo population from the Central Valley of Mexico.

    PubMed

    Santana, Carla; Noris, Gino; Meraz-Ríos, Marco Antonio; Magaña, Jonathan J; Calderon-Aranda, Emma S; Muñoz, Maria de Lourdes; Gómez, Rocío

    2014-01-01

    This study aims to portray the complex diversity of the Mexican Mestizo population, which represents 98.8% of the entire population of Mexico. We compiled extended haplotype data of the Y chromosome from populations in the Central Valley of Mexico (CVM), which we compared with other Mestizo and parental (Amerindian, European, and African) populations. A complex ancestral relationship was found in the CVM population, suggesting cosmopolitan origins. Nevertheless, the most preeminent lineages point toward a European ancestry, where the R1b lineage was most frequent. In addition, important frequencies of Amerindian lineages were also found in the Mestizo sample studied. Interestingly, the Amerindian ancestry showed a remarkable substructure, which was represented by the two main founding lineages: QL54 (× M3) and M3. However, even within each lineage a high diversity was found despite the small number of sample bearers of these lineages. Further, we detected important genetic differences between the CVM populations and the Mexican Mestizo populations from the north and south. This result points to the fact that Mestizo populations present different ancestral proportions, which are related to the demographic events that gave origin to each population. Finally, we provide additional forensic statistical parameters that are useful in the interpretation of genetic analysis where autosomal loci are limited. Our findings illustrate the complex genetic background of the Mexican Mestizo population and reinforce the need to encompass more geographic regions to generate more robust data for forensic applications.

  1. Influence of grazing and available moisture on breeding densities of grassland birds in the central platte river valley, Nebraska

    USGS Publications Warehouse

    Kim, D.H.; Newton, W.E.; Lingle, G.R.; Chavez-Ramirez, F.

    2008-01-01

    We investigated the relationship between grassland breeding bird densities and both grazing and available moisture in the central Platte River Valley. Nebraska between 1980 and 1996. We also compared species richness and community similarity of breeding birds in sedge (Carex spp.) meadows and mesic grasslands. Densities of two species had a significant relationship with grazing and six of seven focal species had a significant relationship with available moisture. Bobolink (Dolichonyx oryzivorus) and Brown-headed Cowbird (Molothrus ater) densities were lower in grazed plots compared to ungrazed plots, whereas Red-winged Blackbird (Agelaius phoeniceus) densities were greater in sedge-meadow plots compared to mesic grassland plots. Bobolink, Dickcissel (Spiza americana). and Brown-headed Cowbird were negatively associated with available moisture with breeding densities peaking during the driest conditions. Our results suggest that wet conditions increase species richness for the community through addition of wetland-dependant and wetland-associated birds, but decrease densities of ground-nesting grassland birds in wet-meadow habitats, whereas dry conditions reduce species richness but increase the density of the avian assemblage. We propose that wet-meadow habitats serve as local refugia for grassland-nesting birds during local or regional droughts.

  2. Analysis of systematic differences from GPS-measured and GRACE-modeled deformation in Central Valley, California

    NASA Astrophysics Data System (ADS)

    Tan, Weijie; Dong, Danan; Chen, Junping; Wu, Bin

    2016-01-01

    Crustal seasonal displacement signals, which are commonly attributed to surface mass redistributions, can be measured by continuous GPS, modeled by GRACE and loading models. Previous studies have shown that the three methods generally agree with one another. However, the discrepancy among them in some regions has not yet been investigated comprehensively. In this paper, we compare the vertical annual displacement signals in the Central Valley, California derived from GPS, GRACE and loading models. The results show a general agreement from these three methods for most sites, which reach the maximum during the dry late summer and autumn. Irregular annual terms with peaks during the wet winter and spring are detected from GPS solutions for the sites located in places with extensive groundwater depletion. However, annual vertical variations for these same sites derived from GRACE and loading models reach the maximum in August and minimum in February. To explain such apparent discrepancy, we find that the vertical components of abnormal sites show a strong correlation with in situ groundwater data, which display peaks during cold months. In addition, with the assistance of water table depth data, we perform hydrological simulations based on Terzaghi's Principle, Mogi's Model and Green's function method. The results suggest that the discrepancy from GPS-measured and GRACE-modeled deformation is induced by the seasonal variations of groundwater.

  3. Predicted Impacts of Conjunctive Water Management Scenarios on Late Summer Streamflow in an Agricultural Groundwater Basin with Limited Storage, Scott Valley, CA.

    NASA Astrophysics Data System (ADS)

    Tolley, D. G., III; Foglia, L.; Harter, T.

    2015-12-01

    Late summer streamflow for the Scott River in northern California has decreased approximately 50% since the mid 1960's, resulting in increased water temperatures and disconnection of the stream. This negatively impacts aquatic habitat of fish species such as coho and fall-run Chinook salmon. In collaboration with local stakeholders, the Scott Valley Integrated Hydrologic Model has been developed, which combines a water budget model and a groundwater-surface water model (MODFLOW) of the 200 km2 basin. The goal of the integrated model is to better understand the hydrologic system of the valley and explore effects of different conjunctive management scenarios on late summer streamflow. The groundwater model has a 100 m lateral resolution with aggregated monthly stresses over a 21 year simulation period (1990-2011). The Scott River and tributaries are represented using the streamflow routing (SFR) package. A sensitivity analysis and calibration were performed by hand using 812 head observations from 50 wells in the basin and average daily streamflow observations from a USGS stream gauge during the simulation period. The calibrated model was used to evaluate two different management scenarios: 1) in-lieu recharge where surface-water instead of groundwater is used to irrigate fields near the river while streamflow is sufficiently high, and 2) managed aquifer recharge during the winter months on agricultural fields located in gulches on the eastern side of the valley using existing infrastructure. Preliminary results indicate that implementation of conjunctive water management may increase late summer streamflow at the gauging station by 1-2 cubic feet per second (cfs), a significant amount given that flows are around 10-20 cfs during this time. This increase in flow during the late summer decreases the length of dry reaches both spatially and temporally, allowing for earlier reconnection of the Scott River and decreased stress on fish.

  4. Climate Change Impact on Meteorological, Hydrological, and Agricultural Drought: A case study of Central Illinois

    NASA Astrophysics Data System (ADS)

    Cai, X.; Wang, D.; Hejazi, M. I.; Valocchi, A. J.

    2010-12-01

    Regional climate change projections based on dynamic downscaling through regional climate models are used to assess drought frequency, intensity and duration, and the impact propagation from meteorological, hydrological and agricultural sectors. The impact on a meteorological drought index (standardized precipitation index, SPI) is first assessed based on daily climate inputs from RCMs driven by three general circulation models (GCMs) (PCM, HadCM3, CCSM3) with different climate sensitivities. Two emission scenarios, relatively high and low emission, are undertaken for each of the three GCMs and dynamically downscaled through the RCMs. Feeding the climate projections to a calibrated hydro-agronomic model at the watershed scale in Central Illinois, hydrological drought (standardized runoff index, SRI) and agricultural drought (standardized soil water index, SSWI) indices and the economic impacts are assessed. RCMs driven by different GCMs predict different changes of drought properties. From the intensity-density-frequency (IDF) curves of SPI, SSWI, and SRI based on the three GCM-RCMs, as expected, the return period increases with the increase of drought duration for a given drought intensity. However, the change of IDF curves from baseline to future years varies with GCM-RCM and drought indicator. HadCM3-RCM predicts moderate increase of drought frequency and CCSM3-RCM predicts significant increase of drought frequency especially for the SSWI and SRI with moderate drought intensity (I<-1). The combination of climate sensitivity and emission scenarios determines the future drought predictions. In general high sensitivity and high emission level results in more serious droughts, particularly, the increase of the frequency of moderate drought is more significant with high emission scenarios. However, even though the climate sensitivity of HadCM3 is high compared to the other two GCMs, the exceedance probability curves of drought indices from HadCM3-RCM is almost

  5. Effects of two contrasting agricultural land uses on shallow groundwater quality in the San Joaquin Valley, California; design and preliminary interpretation

    USGS Publications Warehouse

    Dubrovsky, N.M.; Burow, Karen R.; Gronberg, Jo Ann M.

    1995-01-01

    From 1992 through 1994, the San Joaquin-Tulare Basins Study team of the USGS National Water Quality Assessment program investigated the occurrence and distribution of water quality con- stituents in shallow groundwater underlying two areas of different agricultural land uses: almond orchards and vineyards. The study was restricted to the alluvial fans of the eastern San Joaquin Valley, the area of most groundwater use in the valley. A geographic information system (GIS) was used to delineate the distribution of the two target land uses, to evaluate ancillary data, and to select candidate wells that fit prescribed criteria. Twenty domestic water supply wells were sampled in each of the two areas. In addition, pairs of observation wells were installed and sampled at five of the sites in each area to evaluate whether the water quality in the domestic wells reflects that of the shallow groundwater underlying the target land use. A preliminary evaluation of the results shows that nitrate concentrations in the shallow groundwater are significantly higher in the almond orchard areas than in the vineyard area (p=0.005). In contrast, concentrations of 1,2-dibromo-3-chloropropane (DBCP) were higher in the vineyard area than in the almond orchard area (p=0.032). The most frequently detected pesticides in groundwater underlying both areas were simazine, atrazine, and desethylatrazine (an atrazine degradation product). These observations are explained, in part, by differences in chemical application and hydrogeologic factors.

  6. Assessing the cost of groundwater pollution: the case of diffuse agricultural pollution in the Upper Rhine valley aquifer.

    PubMed

    Rinaudo, J-D; Arnal, C; Blanchin, R; Elsass, P; Meilhac, A; Loubier, S

    2005-01-01

    This paper presents an assessment of the costs of diffuse groundwater pollution by nitrates and pesticides for the industrial and the drinking water sectors in the Upper Rhine valley, France. Pollution costs which occurred between 1988 and 2002 are described and assessed using the avoidance cost method. Geo-statistical methods (kriging) are then used to construct three scenarios of nitrate concentration evolution. The economic consequences of each scenario are then assessed. The estimates obtained are compared with the results of a contingent valuation study carried out in the same study area ten years earlier.

  7. Effects of the 1997 flood on the transport and storage of sediment and mercury within the Carson River Valley, west-central Nevada

    SciTech Connect

    Miller, J.; Barr, R.; Grow, D.; Richardson, D.; Waltman, K.; Lechler, P.; Warwick, J.

    1999-05-01

    Intense, warm rains falling on a heavy snowpack in the Sierra Nevada at the end of December 1996 produced some of the largest floods on record in west-central Nevada. Within the Carson River basin, a peak discharge of 632 cm was recorded at the Fort Churchill gaging station on January 3, 1997, a flow exceeding the 100-yr event. Geomorphic impacts of the event, and the redistribution of mercury (Hg) released to the Carson River valley by Comstock mining operations during the mid- to late-1800s, were assessed by combining field data with the interpretation of aerial photographs. Geomorphic impacts included significant increases in channel width, measuring up to 280% of preflood conditions, and large-scale shifts in channel position, ranging from < 10 to 110 m. Both changes in channel width and position vary as a function of valley morphometry (width and slope) and differ from the long-term trends measured from 1965 to 1991. The 1997 flood also produced widespread overbank deposits that vary morphologically and sedimentologically according to distance from the channel and the nature of the vegetation on the valley floor. Within the overbank deposits, Hg is primarily associated with the fine-grained (< 63 {micro}m) sediment fraction, which makes up a larger percentage of the deposits immediately adjacent to the channel and at the extremities of overbank deposition. Mass balance calculations demonstrate that, along reaches with narrow valleys (< 450 m), approximately 10%--65% of the sediment eroded from the channel banks was stored in overbank deposits, whereas more than 90% of the sediment eroded along reaches with wider valleys was stored on the valley floor. Locally, however, storage exceeded 650% where meander cutoff was extensive. The above data indicate that the erosion, redeposition, and storage of sediment and sediment-bound Hg were greater along reaches characterized by low gradients and wide valley floors. Downstream trends in Hg concentration within the

  8. Evolution of Polaskia chichipe (Cactaceae) under domestication in the Tehuacan Valley, central Mexico: reproductive biology.

    PubMed

    Otero-Arnaiz, Adriana; Casas, Alejandro; Bartolo, Carmen; Pérez-Negrón, Edgar; Valiente-Banuet, Alfonso

    2003-04-01

    Polaskia chichipe, a columnar cactus, is cultivated for its edible fruits in central Mexico. This study analyzed whether artificial selection has modified its reproduction patterns and caused barriers to pollen exchange between wild, managed in situ, and cultivated populations. Anthesis was diurnal (∼16 h in winter, ∼10 h in spring) as well as partly nocturnal (∼12 h in winter, ∼3 h in spring), and flowers were pollinated by bees, hummingbirds, and hawk moths. Manual cross-pollination was ∼37-49% effective in all populations. Self-pollination was ∼12% successful in the wild, but twice as successful (∼22-27%) in managed and cultivated populations. Diurnal pollination was ∼35-55% effective in winter and 100% in spring. Nocturnal pollination was successful only in winter (15%). Crosses among individuals were more effective within populations than among populations, including populations under a similar management regimen. The least successful crosses were between wild and cultivated populations. Flowers were produced in all populations from January to March, but flowering peaks differed by 1 mo among wild, managed, and cultivated populations and by 2 mo between wild and cultivated populations. The latter interrupted pollen exchange in May. Seeds from managed and cultivated populations germinated faster than those from wild individuals. Domestication has seemingly favored self-compatible P. chichipe plants with higher fruit yield, a longer period of fruit production, and faster seed germination, attributes that have resulted in partial reproductive barriers between wild and manipulated populations.

  9. Denitrification in a Shallow Aquifer Underlying a Dairy Farm in the Central Valley of California

    NASA Astrophysics Data System (ADS)

    Esser, B. K.; Beller, H. R.; Carle, S. F.; Hudson, G. B.; Kane, S. R.; McNab, W. W.; Moran, J. E.; Tompson, A. F.

    2004-12-01

    Nitrate loading to shallow aquifers from dairy farm operations presents a serious threat to critical groundwater resources in California. Less well known is the extent to which saturated zone denitrification may mitigate the problem by converting nitrate to the benign end-product nitrogen, before nitrate is transported to deeper aquifers used for drinking water. We are carrying out a multi-disciplinary study of saturated zone denitrification, in a dense network of monitoring points at a 1500-cow dairy in Kings County, California. Detailed vertical profiles of anion and cation concentrations, along with dissolved excess nitrogen were obtained at five-foot intervals using temporary direct-push wells. Results show nitrate concentrations in excess of 100 mg/L over the top few meters of the water column, abruptly falling to less than 5 mg/L below a depth of approximately 10m. Over the same interval, dissolved excess nitrogen concentrations sharply increase, indicating that denitrification is responsible for a significant fraction of the nitrate decrease. This pattern is in effect across the entire dairy site. A key aspect of the project is a concurrent focus on understanding the hydrogeology of the site. Regionally, overdraft over the past several decades has resulted in the development of separate shallow (10 m) and deeper (≥ 40 m) aquifer systems. Recharge to the shallow aquifer is derived from low TDS, isotopically depleted Kings River water from a nearby unlined irrigation canal. Local agricultural pumping from the shallow aquifer and infiltration from irrigation water are significant factors in the shallow system. The deeper aquifer is characterized by intensive regional pumping, rapidly decreasing water levels, and the apparent disposition of the shallow aquifer as a perched system for a 1-km2 or more area surrounding the farm. The air gap separating the aquifers is low in oxygen and undergoes pressure changes as water levels fluctuate below. Age dating and

  10. Outdoor near-roadway, community and residential pollen, carbon dioxide and particulate matter measurements in the urban core of an agricultural region in central CA

    NASA Astrophysics Data System (ADS)

    Shendell, Derek G.; Therkorn, Jennifer H.; Yamamoto, Naomichi; Meng, Qingyu; Kelly, Sarah W.; Foster, Christine A.

    2012-04-01

    We can control asthma through proper clinical and environmental management and education. The U.S. population is growing, urbanizing and aging; seniors of low-to-middle income families are working and living longer. We conducted community-based participatory research in Visalia, Tulare County, California with a prospective, cross-sectional repeated measures design and quantitative and qualitative process; home environment and health-related outcomes data were collected. In this paper, we presented results of the air quality sampling-pollen, carbon dioxide (CO2) and particulate matter (PM) outdoors away from most major sources (agricultural fields, large pollinating trees, etc)-at a community central site close to a mobile line source and participant homes in the cooling season, July, 2009. Weather was hot and dry with light winds; diurnal variation ranged between 65-107 °F (18-42 °C) and 12-76% relative humidity at the study's central site. Co-located active (reference) and passive (PAAS) samplers were used for pollen; passive monitoring for CO2 (Telaire 7001) and active sampling for PM were conducted. Overall, we observed spatial variability in CO2, fine PM (PM2.5), and pollen counts. Weekday and study week average CO2 and PM2.5 concentrations were higher near study homes compared to central site sampling points, but peak measures and overnight/pre-dawn time period averages were elevated at the central site. Pollen counts were typically lower at homes-even if grass, trees, flowers or potted plants were present-compared to the central site closer to and generally downwind from commercial agricultural tree production. Data are new; the nine-county San Joaquin Valley has one pollen count station in the national network, and two of four government outdoor air monitoring stations in the county are in national parks. We suggest-given poor air quality in large part due to PM-adding routine pollen counts to regional/state agency air monitoring sites and more CO2 and PM

  11. A Survey of \\delta18O and \\delta15N Ratios in Ground Water from an Agricultural Community in the San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Glowacki, S. D.; Suen, C. J.

    2004-12-01

    We studied ground water samples from domestic and monitoring wells in an agricultural community in the eastern side of the San Joaquin Valley, California. The study area is rich in alluvial soils creating an extremely fertile farmland. Livestock farms and agricultural fields are abundant in the area. Fifty-four ground water samples were analyzed for \\delta18O and \\delta15N in dissolved nitrate, in addition to nutrients and major minerals. Nitrate concentration levels in groundwater are elevated and affected by agricultural and other activities. Possible sources of nutrients include: a municipal waste-water treatment facility, a raisin processing plant, a meat processing plant, a turkey farm, diary operations, and agricultural fields. However, except for the turkey farm and a diary, we found no statistical significant contribution of nitrate from the other facilities as compared to the rest of the area. The \\delta18O versus \\delta15N ratios plot of dissolved ground water nitrate shows most samples clustered around an area consistent with soil organic nitrogen. In addition, the rest of the samples show a trend that is indicative of denitrification process. Generally, high \\delta15N values are associated with low nitrate concentrations. The isotopic signal of denitrification is particularly pronounced in samples in the vicinity of the waste water treatment facility, where the highest values of \\delta15N and the lowest nitrate concentrations are observed. However, these samples also have elevated chloride concentrations indicating a waste-water source. These data suggest that the denitrification in the subsurface may have been enhanced by bacteria species introduced by the effluence of the plant. [This study was performed with the collaboration of Steven R Silva of USGS, Menlo Park, and Iris Yamagata and Holly Jo Ferrin of California Department of Water Resources.

  12. Reconnaissance of water quality in the High Plains Aquifer beneath agricultural lands, south-central Kansas

    USGS Publications Warehouse

    Stullken, L.E.; Stamer, J.K.; Carr, J.E.

    1987-01-01

    The High Plains of western Kansas was one of 14 areas selected for preliminary groundwater quality reconnaissance by the U.S. Geological Survey 's Toxic Waste--Groundwater Contamination Program. The specific objective was to evaluate the effects of land used for agriculture (irrigated cropland and non-irrigated rangeland) on the water in the High Plains aquifer. Conceptual inferences, based on the information available, would lead one to expect groundwater beneath irrigated cropland to contain larger concentrations of sodium, sulfate, chloride, nitrite plus nitrate, and some water soluble pesticides than water beneath non-irrigated land (range-land) The central part of the Great Bend Prairie, an area of about 1,800 sq mi overlying the High Plains aquifer in south-central Kansas, was selected for the study of agricultural land use because it has sand soils, a shallow water table, relatively large annual precipitation, and includes large areas that are exclusively irrigated cropland or non-irrigated rangeland. As determined by a two-tailed Wilcoxon rank-sum test, concentrations of sodium and alkalinity were significantly larger at the 95% confidence level for water samples from beneath irrigated cropland than from beneath rangeland. No statistically significant difference in concentrations of sulfate, chloride, nitrite plus nitrate, and ammonia, was detected. Concentrations of 2,4-D found in water samples from beneath the rangeland were larger at the 99% confidence level as compared to concentrations of 2,4-D in samples from beneath irrigated cropland. Larger concentrations of sodium and alkalinity were found in water beneath irrigated cropland, and the largest concentration of the pesticide atrazine (triazines were found in three samples) was found in water from the only irrigation well sampled. The sodium and atrazine concentrations found in water from the irrigation well support the premise that water-level drawdown develops under irrigated fields. This diverts

  13. Irrigation Water Supply and Management in the Central High Plains: Can Agriculture Compete for a Limited Resource?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The era of expanding irrigated agriculture in the central high plains has come to an end, and we are likely entering a period of contraction. Contraction has begun in Colorado where the state estimates that current consumptive use exceeds sustainable supplies by about 10%. Groundwater pumping has ...

  14. Long-term trends in climate and hydrology in an agricultural headwater watershed of central Pennsylvania, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change has emerged as a key issue facing agriculture and water resources in the US. Long-term (1968-2012) temperature, precipitation and streamflow data from a small (7.3 km2) watershed in east-central Pennsylvania was used to examine climatic and hydrologic trends in the context of recent c...

  15. Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by use of Nitrogen, Oxygen, and Boron Isotopic Tracers

    NASA Astrophysics Data System (ADS)

    Lockhart, K.; Harter, T.; Grote, M.; Young, M. B.; Eppich, G.; Deinhart, A.; Wimpenny, J.; Yin, Q. Z.

    2014-12-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide, an example of which is the San Joaquin Valley, California. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. Dairy manure and synthetic fertilizers are the major sources of nitrate in groundwater in the San Joaquin Valley, however, septic waste can be a major source in some areas. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Consumption of water containing nitrate above the drinking water limit has been linked to major health effects including low blood oxygen in infants and certain cancers. Knowledge of the proportion of each of the three main nitrate sources (manure, synthetic fertilizer, and septic waste) contributing to individual well nitrate can aid future regulatory decisions. Nitrogen, oxygen, and boron isotopes can be used as tracers to differentiate between the three main nitrate sources. Mixing models quantify the proportional contributions of sources to a mixture by using the concentration of conservative tracers within each source as a source signature. Deterministic mixing models are common, but do not allow for variability in the tracer source concentration or overlap of tracer concentrations between sources. Bayesian statistics used in conjunction with mixing models can incorporate variability in the source signature. We developed a Bayesian mixing model on a pilot network of 32 private domestic wells in the San Joaquin Valley for which nitrate as well as nitrogen, oxygen, and boron isotopes were measured. Probability distributions for nitrogen, oxygen, and boron isotope source signatures for manure, fertilizer, and septic waste were compiled from the literature and from a previous groundwater monitoring project on several

  16. Human effects on the hydrologic system of the Verde Valley, central Arizona, 1910–2005 and 2005–2110, using a regional groundwater flow model

    USGS Publications Warehouse

    Garner, Bradley D.; Pool, D.R.; Tillman, Fred D; Forbes, Brandon T.

    2013-01-01

    Water budgets were developed for the Verde Valley of central Arizona in order to evaluate the degree to which human stresses have affected the hydrologic system and might affect it in the future. The Verde Valley is a portion of central Arizona wherein concerns have been raised about water availability, particularly perennial base flow of the Verde River. The Northern Arizona Regional Groundwater Flow Model (NARGFM) was used to generate the water budgets and was run in several configurations for the 1910–2005 and 2005–2110 time periods. The resultant water budgets were subtracted from one another in order to quantify the relative changes that were attributable solely to human stresses; human stresses included groundwater withdrawals and incidental and artificial recharge but did not include, for example, human effects on the global climate. Three hypothetical and varied conditions of human stresses were developed and applied to the model for the 2005–2110 period. On the basis of this analysis, human stresses during 1910–2005 were found to have already affected the hydrologic system of the Verde Valley, and human stresses will continue to affect the hydrologic system during 2005–2110. Riparian evapotranspiration decreased and underflow into the Verde Valley increased because of human stresses, and net groundwater discharge to the Verde River in the Verde Valley decreased for the 1910–2005 model runs. The model also showed that base flow at the upstream end of the study area, as of 2005, was about 4,900 acre-feet per year less than it would have been in the absence of human stresses. At the downstream end of the Verde Valley, base flow had been reduced by about 10,000 acre-feet per year by the year 2005 because of human stresses. For the 2005–2110 period, the model showed that base flow at the downstream end of the Verde Valley may decrease by an additional 5,400 to 8,600 acre-feet per year because of past, ongoing, and hypothetical future human

  17. Biomonitoring with Micronuclei Test in Buccal Cells of Female Farmers and Children Exposed to Pesticides of Maneadero Agricultural Valley, Baja California, Mexico

    PubMed Central

    Castañeda-Yslas, Idalia Jazmin; Arellano-García, María Evarista; García-Zarate, Marco Antonio; Ruíz-Ruíz, Balam; Zavala-Cerna, María Guadalupe; Torres-Bugarín, Olivia

    2016-01-01

    Feminization of the agricultural labor is common in Mexico; these women and their families are vulnerable to several health risks including genotoxicity. Previous papers have presented contradictory information with respect to indirect exposure to pesticides and DNA damage. We aimed to evaluate the genotoxic effect in buccal mucosa from female farmers and children, working in the agricultural valley of Maneadero, Baja California. Frequencies of micronucleated cells (MNc) and nuclear abnormalities (NA) in 2000 cells were obtained from the buccal mucosa of the study population (n = 144), divided in four groups: (1) farmers (n = 37), (2) unexposed (n = 35), (3) farmers' children (n = 34), and (4) unexposed children (n = 38). We compared frequencies of MNc and NA and fitted generalized linear models to investigate the interaction between these variables and exposition to pesticides. Differences were found between farmers and unexposed women in MNc (p < 0.0001), CC (p = 0.3376), and PN (p < 0.0001). With respect to exposed children, we found higher significant frequencies in MNc (p < 0.0001), LN (p < 0.0001), CC (p < 0.0001), and PN (p < 0.004) when compared to unexposed children. Therefore working as a farmer is a risk for genotoxic damage; more importantly indirectly exposed children were found to have genotoxic damage, which is of concern, since it could aid in future disturbances of their health. PMID:26981119

  18. Residential Agricultural Pesticide Exposures and Risk of Neural Tube Defects and Orofacial Clefts Among Offspring in the San Joaquin Valley of California

    PubMed Central

    Yang, Wei; Carmichael, Suzan L.; Roberts, Eric M.; Kegley, Susan E.; Padula, Amy M.; English, Paul B.; Shaw, Gary M.

    2014-01-01

    We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997–2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects. PMID:24553680

  19. Biomonitoring with Micronuclei Test in Buccal Cells of Female Farmers and Children Exposed to Pesticides of Maneadero Agricultural Valley, Baja California, Mexico.

    PubMed

    Castañeda-Yslas, Idalia Jazmin; Arellano-García, María Evarista; García-Zarate, Marco Antonio; Ruíz-Ruíz, Balam; Zavala-Cerna, María Guadalupe; Torres-Bugarín, Olivia

    2016-01-01

    Feminization of the agricultural labor is common in Mexico; these women and their families are vulnerable to several health risks including genotoxicity. Previous papers have presented contradictory information with respect to indirect exposure to pesticides and DNA damage. We aimed to evaluate the genotoxic effect in buccal mucosa from female farmers and children, working in the agricultural valley of Maneadero, Baja California. Frequencies of micronucleated cells (MNc) and nuclear abnormalities (NA) in 2000 cells were obtained from the buccal mucosa of the study population (n = 144), divided in four groups: (1) farmers (n = 37), (2) unexposed (n = 35), (3) farmers' children (n = 34), and (4) unexposed children (n = 38). We compared frequencies of MNc and NA and fitted generalized linear models to investigate the interaction between these variables and exposition to pesticides. Differences were found between farmers and unexposed women in MNc (p < 0.0001), CC (p = 0.3376), and PN (p < 0.0001). With respect to exposed children, we found higher significant frequencies in MNc (p < 0.0001), LN (p < 0.0001), CC (p < 0.0001), and PN (p < 0.004) when compared to unexposed children. Therefore working as a farmer is a risk for genotoxic damage; more importantly indirectly exposed children were found to have genotoxic damage, which is of concern, since it could aid in future disturbances of their health.

  20. Modeling vadose zone processes during land application of food-processing waste water in California's Central Valley.

    PubMed

    Miller, Gretchen R; Rubin, Yoram; Mayer, K Ulrich; Benito, Pascual H

    2008-01-01

    Land application of food-processing waste water occurs throughout California's Central Valley and may be degrading local ground water quality, primarily by increasing salinity and nitrogen levels. Natural attenuation is considered a treatment strategy for the waste, which often contains elevated levels of easily degradable organic carbon. Several key biogeochemical processes in the vadose zone alter the characteristics of the waste water before it reaches the ground water table, including microbial degradation, crop nutrient uptake, mineral precipitation, and ion exchange. This study used a process-based, multi-component reactive flow and transport model (MIN3P) to numerically simulate waste water migration in the vadose zone and to estimate its attenuation capacity. To address the high variability in site conditions and waste-stream characteristics, four food-processing industries were coupled with three site scenarios to simulate a range of land application outcomes. The simulations estimated that typically between 30 and 150% of the salt loading to the land surface reaches the ground water, resulting in dissolved solids concentrations up to sixteen times larger than the 500 mg L(-1) water quality objective. Site conditions, namely the ratio of hydraulic conductivity to the application rate, strongly influenced the amount of nitrate reaching the ground water, which ranged from zero to nine times the total loading applied. Rock-water interaction and nitrification explain salt and nitrate concentrations that exceed the levels present in the waste water. While source control remains the only method to prevent ground water degradation from saline wastes, proper site selection and waste application methods can reduce the risk of ground water degradation from nitrogen compounds.

  1. Hydrology of the Sevier-Sigurd ground-water basin and other ground-water basins, central Sevier Valley, Utah.

    USGS Publications Warehouse

    Lambert, P.M.; Mason, J.L.; Puchta, R.W

    1995-01-01

    The hydrologic system in the central Sevier Valley, and more specifically the Sevier-Sigurd basin, is a complex system in which surface- and ground-water systems are interrelated. Seepage from an extensive irrigation system is the primary source of recharge to the basin-fill aquifer in the Sevier-Sigurd basin.Water-quality data indicate that inflow from streams and subsurface inflow that intersect evaporite deposits in the Arapien Shale does not adversely affect ground-water quality in the Sevier-Sigurd basin. Stable-isotope data indicate that large sulfate concentrations in water from wells are from the dissolution of gypsum within the basin fill rather than inflow from the Arapien Shale.A ground-water-flow model of the basin-fill aquifer in the Sevier-Sigurd basin was calibrated to steady-state conditions and transient conditions using yearly water-level changes from 1957-88 and monthly water-level changes from 1958-59. Predictive simulations were made to test the effects of reduced recharge from irrigation and increased well discharge. To simulate the effects of conversion from flood to sprinkler irrigation, recharge from irrigated fields was reduced by 50 percent. After twenty years, this reduction resulted in water-level declines of 1 to 8 feet in most of the basin, and a reduction in ground-water discharge to the Sevier River of 4,800 acre-ft/yr. Water-level declines of as much as 12 feet and a reduction in recharge to the Sevier River of 4,800 acre-ft/yr were the result of increasing well discharge near Richfield and Monroe by 25,000 acre-ft/yr. 

  2. Monitoring unrest in a large silicic caldera, the long Valley-inyo craters volcanic complex in east-central California

    USGS Publications Warehouse

    Hill, D.P.

    1984-01-01

    Recent patterns of geologic unrest in long Valley caldera in east-central California emphasize that this large, silicic volcanic system and the adjacent, geologically youthful Inyo-Mono Craters volcanic chain are still active and capable of producing locally hazardous volcanic eruptions. A series of four magnitude -6 earthquakes in May 1980 called attention to this current episode of unrest, and subsequent activity has included numerous earthquake swarms in the south moat of the caldera accompanied by inflation of the resurgent dome by more than 50 cm over the last five years. The seismicity associated with this unrest is currently monitored by a network of 31 telemetered seismic stations with an automatic processing system that yelds hypocentral locations and earthquake magnitudes in near-real time. Deformation of the ground is monitored by a) a series of overlapping trilateration networks that provide coverage ranging from annual measurements of regional deformation to daily measurements of deformation local to the active, southern section of the caldera, b) a regional network of level lines surveyed annually, c) a regional network of precise gravity stations occupied annually, d) local, L-shaped level figures surveyed every few months, and e) a network of fourteen borehole tiltmeter clusters (two instruments in each cluster) and a borehole dilatometer, the telemetered signals from which provide continuous data on deformation rates. Additional telemetered data provide continuous information on fluctuations in the local magnetic field, hydrogen gas emission rates at three sites, and water level and temperatures in three wells. Continuous data on disharge rates and temperatures from hot springs and fumaroles are collected by several on-site recorders within the caldera, and samples for liquid and gas chemistry are collected several times per year from selected hot springs and fumaroles. ?? 1984 Intern. Association of Volcanology and Chemistry of the Earth

  3. Heritability of Cognitive Functions in Families of Successful Cognitive Aging Probands from the Central Valley of Costa Rica

    PubMed Central

    Greenwood, Tiffany A.; Beeri, Michal S.; Schmeidler, James; Valerio, Daniel; Raventós, Henriette; Mora-Villalobos, Lara; Camacho, Karla; Carrión-Baralt, José R.; Angelo, Gary; Almasy, Laura; Sano, Mary; Silverman, Jeremy M.

    2012-01-01

    We sought to identify cognitive phenotypes for family/genetic studies of successful cognitive aging (SCA; maintaining intact cognitive functioning while living to late old age).We administered a battery of neuropsychological tests to nondemented nonagenarians (n = 65; mean age = 93.4±3.0) and their offspring (n = 188; mean age = 66.4±5.0) from the Central Valley of Costa Rica. After covarying for age, gender, and years of education, as necessary, heritability was calculated for cognitive functions at three pre-defined levels of complexity: specific neuropsychological functions (e.g., delayed recall, sequencing), three higher level cognitive domains (memory, executive functions, attention), and an overall neuropsychological summary. The highest heritability was for delayed recall (h2 = 0.74, se = 0.14, p < 0.0001) but significant heritabilities involving memory were also observed for immediate recall (h2 = 0.50), memory as a cognitive domain (h2 = 0.53), and the overall neuropsychological summary (h2 = 0.42). Heritabilities for sequencing (h2 = 0.42), fluency (h2 = 0.39), abstraction (h2 = 0.36), and the executive functions cognitive domain (h2 = 0.35) were also significant. In contrast, the attention domain and memory recognition were not significantly heritable in these families. Among the heritable specific cognitive functions, a strong pleiotropic effect (i.e., evidence that these may be influenced by the same gene or set of genes) for delayed and immediate recall was identified (bivariate statistic = 0.934, p < 0.0001) and more modest but significant effects were found for four additional bivariate relationships. The results support the heritability of good cognitive function in old age and the utilization of several levels of phenotypes, and they suggest that several measures involving memory may be especially useful for family/genetic studies of SCA. PMID:21908911

  4. Water supply patterns in two agricultural areas of Central Germany under climate change conditions

    NASA Astrophysics Data System (ADS)

    Tölle, M. H.; Moseley, C.; Panferov, O.; Busch, G.; Knohl, A.

    2012-04-01

    Increasing emissions of greenhouse gases and increasing prices for fossil fuels have highlighted the demand for CO2 "neutral" renewable energy sources, e.g. short rotation forestry systems used for bioenergy. These systems might be vulnerable to changes in temperature, precipitation and occurrence of extreme weather events. To estimate success or failure of such short rotation coppices in a certain area we need regional climate projections and risk assessment. Changes of water supply patterns in two agriculturally extensively used regions in Central Germany (around Göttingen and Großfahner) with different climate conditions but both in the temperate climate zone are explored. The study is carried out under present conditions as well as under projected climate change conditions (1971-2100) using A1B and B1 climate scenarios downscaled for Europe. Analysis of precipitation bias shows regional differences: a strong bias in Göttingen area and a weaker bias in the Großfahner area. A bias correction approach, Quantile mapping, is applied to the ensemble results for both areas for winter and summer seasons. By using quantile regression on the seasonal Standardized Precipitation Indices (SPIs) as indicator for water supply conditions we found that precipitation is expected to increase in winter in all quantiles of the distribution for Göttingen area during the 21th century. Heavy precipitation is also expected to increase for Großfahner area suggesting a trend to wetter extremes in winter for the future. This winter precipitation increase could trigger runoff and soil erosion risk enhancing the severity of floods. Increasing winter availability of water could enhance local water supply in spring. For both areas no significant change in summer was found over the whole time period. Although the climate change signal of the SPI indicate mild dryer conditions in summer at the end of the 21st century which may trigger water shortage and summer drying associated with above

  5. Comparison of particle-tracking and lumped-parameter models for determining groundwater age distributions and nitrate in water-supply wells, Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Jurgens, B. C.; Bohlke, J. K.; Kauffman, L. J.; Belitz, K.

    2013-12-01

    Age distributions for 30 production wells (mostly public-supply) were determined using two methods: 1) calibration of age tracer data with lumped parameter models (LPMs) and 2) by advective particle tracking (PT) simulations using MODPATH and a regional steady-state groundwater flow model. The LPMs were calibrated with measurements of 3H, 3He(trit), and 14C by minimizing the Chi-square test statistic using a non-linear solver. A partial exponential model (PEM) was the primary LPM used in this study and a combination of two PEMs were used in cases where binary age mixtures were identified. The PEM is a reformulated version of the exponential model that is parameterized to simulate the age distribution in a well that is screened over any finite interval within the aquifer. The regional numerical model was calibrated to water-levels and gradients, and simulated PT age tracer concentrations were calibrated to the MODPATH porosity value. Age distributions were then used to predict nitrate concentrations in wells using agricultural application rates of nitrate in the central eastside of the San Joaquin Valley, California. Both methods showed that wells in the study area captured groundwater with a broad range of ages, spanning decades to millennia. Age distributions from the LPMs predicted age tracer and nitrate concentrations more accurately than the regional PT simulation; whereas PT simulations incorporating more detailed information about water-levels and hydraulic gradients near wells also provided good fits. 14C concentrations were not simulated well by the regional steady-state model, especially for wells with a significant fraction of old groundwater, because the model simulates the current, perturbed system and does not simulate recharge rates and velocities of the predevelopment system. Results from the LPMs yielded an average recharge rate of 0.55 m/yr, which was similar to the average recharge rate of 0.54 m/yr determined from a water budget analysis for the

  6. Commercial production of ethanol in the San Luis Valley, Colorado. Final Report

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Sherwood, P.B.; Boswell, B.S.; Walter, K.M.; Hart, M.L.

    1983-07-01

    The purpose of this study is to assess the commercial feasibility of producing between 76 and 189 million liters (20 and 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (KGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstock for the production of ethanol.

  7. Commercial production of ethanol in the San Luis Valley, Colorado. Final report

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Boswell, B.S.; Walter, K.M.; Hart, M.L.; Sherwood, P.B.

    1983-07-01

    The commercial feasibility of producing between 76 and 189 million liters (20 to 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source was assessed. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (IGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstocks for the production of ethanol.

  8. Children's exposure to chlorpyrifos and parathion in an agricultural community in central Washington State.

    PubMed Central

    Fenske, Richard A; Lu, Chensheng; Barr, Dana; Needham, Larry

    2002-01-01

    We measured two diethyl organophosphorus (OP) pesticides--chlorpyrifos and parathion--in residences, and their metabolic by-products, in the urine of children 6 years old or younger in a central Washington State agricultural community. Exposures to two dimethyl OP pesticides (azinphos-methyl and phosmet) in this same population have been reported previously. We categorized children by parental occupation and by household proximity to pesticide-treated farmland. Median chlorpyrifos house dust concentrations were highest for the 49 applicator homes (0.4 microg/g), followed by the 12 farm-worker homes (0.3 microg/g) and the 14 nonagricultural reference homes (0.1 microg/g), and were statistically different (p < 0.001); we observed a similar pattern for parathion in house dust. Chlorpyrifos was measurable in the house dust of all homes, whereas we found parathion in only 41% of the homes. Twenty-four percent of the urine samples from study children had measurable 3,5,6-trichloro-2-pyridinol (TCPy) concentrations [limits of quantitation (LOQ) = 8 microg/L], and 7% had measurable 4-nitrophenol concentrations (LOQ = 9 microg/L). Child urinary metabolite concentrations did not differ across parental occupational classifications. Homes in close proximity (200 ft/60 m) to pesticide-treated farmland had higher chlorpyrifos (p = 0.01) and parathion (p = 0.014) house dust concentrations than did homes farther away, but this effect was not reflected in the urinary metabolite data. Use of OP pesticides in the garden was associated with an increase in TCPy concentrations in children's urine. Parathion concentrations in house dust decreased 10-fold from 1992 to 1995, consistent with the discontinued use of this product in the region in the early 1990s. PMID:12003762

  9. Central nervous system function and organophosphate insecticide use among pesticide applicators in the Agricultural Health Study

    PubMed Central

    Starks, Sarah E; Gerr, Fred; Kamel, Freya; Lynch, Charles F; Jones, Michael P; Alavanja, Michael C; Sandler, Dale P; Hoppin, Jane A

    2011-01-01

    Acute organophosphate (OP) pesticide exposure is associated with adverse central nervous system (CNS) outcomes, however, little is known about the neurotoxicity of chronic exposures that do not result in acute poisoning. To examine associations between long-term pesticide use and CNS function, neurobehavioral (NB) tests were administered to licensed pesticide applicators enrolled in the Agricultural Health Study (AHS) in Iowa and North Carolina. Between 2006 and 2008, 701 male participants completed nine NB tests to assess memory, motor speed and coordination, sustained attention, verbal learning and visual scanning and processing. Data on ever-use and lifetime days of use of 16 OP pesticides were obtained from AHS interviews conducted before testing between 1993 and 2007 and during the NB visit. The mean age of participants was 61 years (SD = 12). Associations between pesticide use and NB test performance were estimated with linear regression controlling for age and outcome-specific covariates. NB test performance was associated with lifetime days of use of some pesticides. Ethoprop was significantly associated with reduced performance on a test of motor speed and visual scanning. Malathion was significantly associated with poor performance on a test of visual scanning and processing. Conversely, we observed significantly better test performance for five OP pesticides. Specifically, chlorpyrifos, coumaphos, parathion, phorate, and tetrachlorvinphos were associated with better verbal learning and memory; coumaphos was associated with better performance on a test of motor speed and visual scanning; and parathion was associated with better performance on a test of sustained attention. Several associations varied by state. Overall, our results do not provide strong evidence that long-term OP pesticide use is associated with adverse CNS-associated NB test performance among this older sample of pesticide applicators. Potential reasons for these mostly null associations

  10. Linking Knowledge and Action for a Transition to Sustainability: Lessons from the Yaqui Valley agricultural region and other case studies

    NASA Astrophysics Data System (ADS)

    Matson, P. A.

    2012-12-01

    In recent years, there has been a call-to-arms for the science community to focus on sustainability challenges, and many research programs and projects, publication venues, and meetings provide evidence of progress in this realm. Purposeful actions to link this new knowledge with action for meeting sustainability goals are less evident. This talk will provide several examples of linking knowledge and action for sustainability in agricultural systems of Sonora, Mexico, and will summarize some of the lessons learned from this case study in comparison with a number of others.

  11. Zircon Geochemistry of Granitic Rocks from Ong Valley and Moraine Canyon in the Central Transantarctic Mountains, Antarctica

    NASA Astrophysics Data System (ADS)

    Liu, J.; Morgan, D. J.; Claiborne, L. L.; Padilla, A. J.; Edwards, K. L.; Putkonen, J.; Bibby, T.; Cribb, J. W.

    2015-12-01

    A number of granitic rocks exposed throughout the Central Transantarctic Mountains (CTAM) are thought to have been generated during and following the Ross Orogeny (late Cambrian to early Ordovician). Understanding the origin of these rocks can help improve our understanding of the tectonic events responsible for the suturing of Gondwana. In this study, we use zircon as a tool to investigate the magmatic origins and evolution of CTAM granites. Zircon has a low solubility in almost all melt and fluid compositions, is stable and resistant to alteration at Earth's surface, and is physically durable during transport. These features enable it to survive many crustal processes during which most other minerals are destroyed, thus preserving an important geochemical record of its crystallizing environments. We collected granitic samples from two sites in the CTAM: Ong Valley (157.5°E, 83.25°S), where the Hope Granite is exposed intruded into pre-Cambrian gneisses, and Moraine Canyon (157.55°W, 86.1°S), where bedrock exposure is dominated by a silicic porphyry of the Wyatt Formation. Our zircon U-Pb data, collected in-situ by laser ablation (LA) ICP-MS, suggests that the Hope Granite has a mean weighted crystallization age of 582 ± 23 Ma (2σ; n=26), older than the published age (510 ± 9 Ma, 1σ; whole-rock Rb-Sr isochrons; Faure & Mensing, 2010). The spread in individual zircon ages is consistent with previous estimates for the duration of intrusion (~20 Myr) of the Hope Granite. Published ages for Wyatt Fm rocks range from ~525 to ~800 Ma, but their origin is uncertain. We will analyze zircons from the Wyatt porphyry for U-Pb isotopes (by LA-ICP-MS) to better constrain its age. In addition, we will obtain trace element compositions of zircons from both intrusions to investigate their magmatic origins. This will allow us to explore potential geochemical connections between the intrusions, and may yield additional insight into the tectonic events involved in the Ross

  12. Integrating High Resolution Water Footprint and GIS for Promoting Water Efficiency in the Agricultural Sector: A Case Study of Plantation Crops in the Jordan Valley.

    PubMed

    Shtull-Trauring, Eliav; Aviani, Ido; Avisar, Dror; Bernstein, Nirit

    2016-01-01

    Addressing the global challenges to water security requires a better understanding of humanity's use of water, especially the agricultural sector that accounts for 70% of global withdrawals. This study combined high resolution-data with a GIS system to analyze the impact of agricultural practices, crop type, and spatial factors such as drainage basins, climate, and soil type on the Water Footprint (WF) of agricultural crops. The area of the study, the northern Lower Jordan Valley, covers 1121 ha in which three main plantation crops are grown: banana (cultivated in open-fields or net-houses), avocado and palm-dates. High-resolution data sources included GIS layers of the cultivated crops and a drainage pipe-system installed in the study area; meteorological data (2000-2013); and crop parameters (yield and irrigation recommendations). First, the study compared the WF of the different crops on the basis of yield and energy produced as well as a comparison to global values and local irrigation recommendations. The results showed that net-house banana has the lowest WF based on all different criteria. However, while palm-dates showed the highest WF for the yield criteria, it had the second lowest WF for energy produced, emphasizing the importance of using multiple parameters for low and high yield crop comparisons. Next, the regional WF of each drainage basin in the study area was calculated, demonstrating the strong influence of the Gray WF, an indication of the amount of freshwater required for pollution assimilation. Finally, the benefits of integrating GIS and WF were demonstrated by computing the effect of adopting net-house cultivation throughout the area of study with a result a reduction of 1.3 MCM irrigation water per year. Integrating the WF methodology and local high-resolution data using GIS can therefore promote and help quantify the benefits of adopting site-appropriate crops and agricultural practices that lower the WF by increasing yield, reducing water

  13. Integrating High Resolution Water Footprint and GIS for Promoting Water Efficiency in the Agricultural Sector: A Case Study of Plantation Crops in the Jordan Valley

    PubMed Central

    Shtull-Trauring, Eliav; Aviani, Ido; Avisar, Dror; Bernstein, Nirit

    2016-01-01

    Addressing the global challenges to water security requires a better understanding of humanity's use of water, especially the agricultural sector that accounts for 70% of global withdrawals. This study combined high resolution-data with a GIS system to analyze the impact of agricultural practices, crop type, and spatial factors such as drainage basins, climate, and soil type on the Water Footprint (WF) of agricultural crops. The area of the study, the northern Lower Jordan Valley, covers 1121 ha in which three main plantation crops are grown: banana (cultivated in open-fields or net-houses), avocado and palm-dates. High-resolution data sources included GIS layers of the cultivated crops and a drainage pipe-system installed in the study area; meteorological data (2000–2013); and crop parameters (yield and irrigation recommendations). First, the study compared the WF of the different crops on the basis of yield and energy produced as well as a comparison to global values and local irrigation recommendations. The results showed that net-house banana has the lowest WF based on all different criteria. However, while palm-dates showed the highest WF for the yield criteria, it had the second lowest WF for energy produced, emphasizing the importance of using multiple parameters for low and high yield crop comparisons. Next, the regional WF of each drainage basin in the study area was calculated, demonstrating the strong influence of the Gray WF, an indication of the amount of freshwater required for pollution assimilation. Finally, the benefits of integrating GIS and WF were demonstrated by computing the effect of adopting net-house cultivation throughout the area of study with a result a reduction of 1.3 MCM irrigation water per year. Integrating the WF methodology and local high-resolution data using GIS can therefore promote and help quantify the benefits of adopting site-appropriate crops and agricultural practices that lower the WF by increasing yield, reducing

  14. Annual and seasonal differences in pesticide mixtures within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only a limited amount of information on pesticide mixtures within agricultural headwater streams is available. A greater understanding of the characteristics of pesticide mixtures and their spatial and temporal trends within agricultural headwater streams is needed to evaluate the risks of pesticid...

  15. Ascii grids of predicted pH in depth zones used by domestic and public drinking water supply depths, Central Valley, California

    USGS Publications Warehouse

    Zamora, Celia; Nolan, Bernard T.; Gronberg, JoAnn M.

    2017-01-01

    The ascii grids associated with this data release are predicted distributions of continuous pH at the drinking water depth zones in the groundwater of Central Valley, California. The two prediction grids produced in this work represent predicted pH at the domestic supply and public supply drinking water depths, respectively and are bound by the alluvial boundary that defines the Central Valley. A depth of 46 m was used to stratify wells into the shallow and deep aquifer and were derived from depth percentiles associated with domestic and public supply in previous work by Burow et al. (2013). In this work, the median well depth categorized as domestic supply was 30 meters below land surface and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically Boosted Regression Trees (BRT) with a gaussian error distribution within a statistical learning framework within R's computing framework (http://www.r-project.org/). The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1337 wells, and was compiled from two sources: US Geological Survey (USGS) National Water Information System (NWIS) Database (all data are publicly available from the USGS: http://waterdata.usgs.gov/ca/nwis/nwis) and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: http://www.waterboards.ca.gov/gama/geotracker_gama.shtml). Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993-2014 was used. A total of 1003 wells (training dataset) were used to train the BRT model and 334 wells (hold-out dataset) were used to validate the prediction model. The training r-squared was

  16. Natural establishment of woody species on abandoned agricultural fields in the lower Mississippi Valley: first- and second-year results

    USGS Publications Warehouse

    Allen, J.A.; McCoy, J.W.; Keeland, B.D.

    1998-01-01

    The natural establishment of woody seedlings on abandoned agricultural fields was investigated at sites in Louisiana and Mississippi. Series of disked and undisked plots originating at forest edges and oriented in cardinal directions were established on fields at each site. During the firest 2 years, seedling recruitment was dominated by sweetgum, sugarberry, and elms at both sites. Seedling establishment was strongly affected by direction from mature forest and disking, and to a slightly lesser degree by distance from mature forest. Slightly under half of the variation in seedling numbers per plot was explained by the effects of direction, distance, and disking, indicating that other factors also may play an important role in seedling recruitment.

  17. Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley

    USGS Publications Warehouse

    Faulkner, Stephen P.; Baldwin, Michael J.; Barrow, Wylie C.; Waddle, Hardin; Keeland, Bobby D.; Walls, Susan C.; James, Dale; Moorman, Tom

    2010-01-01

    The degree to which these conservation practices can restore ecosystem functions and services is not well known. This project was initiated to quantify existing ecological services derived from USDA conservation practices in the MAV as part of the USDA Conservation Effects Assessment Project, Wetlands Component (CEAP-Wetlands). The U.S. Geological Survey (USGS), in collaboration with the USDA Natural Resources Conservation Service, the USDA Farm Service Agency, the U.S. Fish and Wildlife Service, and Ducks Unlimited, collected data on soils, vegetation, nitrogen cycling, migratory birds, and amphibians from 88 different sites between 2006 and 2008. Results from restored WRP sites were compared to baseline data from active agricultural cropland (AG) to evaluate changes in ecosystem services.

  18. Toxicity of agricultural subsurface drainwater from the San Joaquin Valley, California to juvenile chinook salmon and striped bass

    USGS Publications Warehouse

    Saiki, Michael K.; Jennings, Mark R.; Wiedmeyer, Raymond H.

    1992-01-01

    Juvenile chinook salmon Oncorhynchus tshawytscha (40-50 mm total length, TL) and striped bass Morone saxatilis (30-40 mm TL) were exposed to serial dilutions (100, 50, 25, and 12.5%) of agricultural subsurface drainwater (WWD), reconstituted drainwater (RWWD), and reconstituted seawater (IO). Agricultural subsurface drainwater contained naturally elevated concentrations of major ions (such as sodium and sulfate) and trace elements (especially boron and selenium), RWWD contained concentrations of major ions that mimicked those in WWD but trace elements were not elevated, and IO contained concentrations of total dissolved salt that were similar to those in WWD and RWWD but chloride replaced sulfate as the dominant anion. After 28 d of static exposure, over 75% of the chinook salmon in 100% WWD had died, whereas none had died in other dilutions and water types. Growth of chinook salmon in WWD and RWWD, but not in IO, exhibited dilution responses. All striped bass died in 100% WWD within 23 d, whereas 19 of 20 striped bass had died in 100% RWWD after 28 d. In contrast, none died in 100% IO. Growth of striped bass was impaired only in WWD. Fish in WWD accumulated as much as 200 μg/g (dry-weight basis) of boron, whereas fish in control water accumulated less than 3.1 μg/g. Although potentially toxic concentrations of selenium occurred in WWD (geometric means, 158-218 μg/L), chinook salmon and striped bass exposed to this water type accumulated 5.7 μg Se/g or less. These findings indicate that WWD was toxic to chinook salmon and striped bass. Judging from available data, the toxicity of WWD was due primarily to high concentrations of major ions present in atypical ratios, to high concentrations of sulfate, or to both. High concentrations of boron and selenium also may have contributed to the toxicity of WWD, but their effects were not clearly delineated.

  19. Geophysical studies in the vicinity of Blue Mountain and Pumpernickel Valley near Winnemucca, north-central Nevada

    USGS Publications Warehouse

    Ponce, David A.

    2012-01-01

    From May 2008 to September 2009, the U.S. Geological Survey (USGS) collected data from more than 660 gravity stations, 100 line-km of truck-towed magnetometer traverses, and 260 physical-property sites in the vicinity of Blue Mountain and Pumpernickel Valley, northern Nevada (fig. 1). Gravity, magnetic, and physical-property data were collected to study regional crustal structures as an aid to understanding the geologic framework of the Blue Mountain and Pumpernickel Valley areas, which in general, have implications for mineral- and geothermal-resource investigations throughout the Great Basin.

  20. Long Valley Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Hill, David

    2008-01-01

    The ~300-year-old lava on Paoha Island in Mono Lake was produced by the most recent eruption in the Long Valley Caldera area in east-central California. The Long Valley Caldera was formed by a massive volcanic eruption 760,000 years ago. The region is monitored by the Long Valley Observatory (LVO), one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about the Long Valley Caldera region and LVO at http://volcanoes.usgs.gov/lvo.

  1. California GAMA Special Study: An isotopic and dissolved gas investigation of nitrate source and transport to a public supply well in California's Central Valley

    SciTech Connect

    Singleton, M J; Moran, J E; Esser, B K; Roberts, S K; Hillegonds, D J

    2010-04-14

    This study investigates nitrate contamination of a deep municipal drinking water production well in Ripon, CA to demonstrate the utility of natural groundwater tracers in constraining the sources and transport of nitrate to deep aquifers in the Central Valley. The goal of the study was to investigate the origin (source) of elevated nitrate and the potential for the deep aquifer to attenuate anthropogenic nitrate. The site is ideal for such an investigation. The production well is screened from 165-325 feet below ground surface and a number of nearby shallow and deep monitoring wells were available for sampling. Furthermore, potential sources of nitrate contamination to the well had been identified, including a fertilizer supply plant located approximately 1000 feet to the east and local almond groves. A variety of natural isotopic and dissolved gas tracers including {sup 3}H-{sup 3}He groundwater age and the isotopic composition of nitrate are applied to identify nitrate sources and to characterize nitrate transport. An advanced method for sampling production wells is employed to help identify contaminant contributions from specific screen intervals. Nitrate transport: Groundwater nitrate at this field site is not being actively denitrified. Groundwater parameters indicate oxic conditions, the dissolved gas data shows no evidence for excess nitrogen as the result of denitrification, and nitrate-N and -O isotope compositions do not display patterns typical of denitrification. Contaminant nitrate source: The ambient nitrate concentration in shallow groundwater at the Ripon site ({approx}12 mg/L as nitrate) is typical of shallow groundwaters affected by recharge from agricultural and urban areas. Nitrate concentrations in Ripon City Well 12 (50-58 mg/L as nitrate) are significantly higher than these ambient concentrations, indicating an additional source of anthropogenic nitrate is affecting groundwater in the capture zone of this municipal drinking water well. This

  2. Quaternary stratigraphy and tectonics, and late prehistoric agriculture of the Safford Basin (Gila and San Simon river valleys), Graham County, Arizona

    USGS Publications Warehouse

    Houser, Brenda B.; Pearthree, Phillip A.; Homburg, Jeffry A.; Thrasher, Lawrence C.

    2004-01-01

    This guidebook accompanied the 46th annual meeting of the Rocky Mountain Cell of the Friends of the Pleistocene (FOP) and the 2002 Fall Field Trip of the Arizona Geological Society. The meeting and field trip were held in the Safford Basin, southeastern Arizona. The Friends of the Pleistocene is an informal gathering of Quaternary geologists, geomorphologists, and pedologists who meet annually for a field conference. The first part of the guidebook consists of road logs with descriptions of stops covering the three days of the field trip. An overview of the geology of the Safford Basin is given in Stop 1-1. The second part of the guidebook consists of four short papers that discuss adjacent areas or that expand upon the road log descriptions of the field trip stops. The first paper by Reid and Buffler is a summary of upper Cenozoic depositional facies in the Duncan Basin, the first basin to the east of the Safford Basin. The next three papers expand upon (1) the soil study of the gridded field agricultural complex (Stop 2-3, Homburg and Sandor), (2) the vertebrate fossils of the San Simon Valley in the southeastern part of the Safford Basin (Stop 3-1, Thrasher), and (3) paleoIndian irrigation systems and settlements in Lefthand Canyon at the foot of the Pinaleno Mountains (Stop 3-2, Neely and Homburg).

  3. A system of regional agricultural land use mapping tested against small scale Apollo 9 color infrared photography of the Imperial Valley (California)

    USGS Publications Warehouse

    Johnson, Claude W.; Browden, Leonard W.; Pease, Robert W.

    1969-01-01

    Interpretation results of the small scale ClR photography of the Imperial Valley (California) taken on March 12, 1969 by the Apollo 9 earth orbiting satellite have shown that world wide agricultural land use mapping can be accomplished from satellite ClR imagery if sufficient a priori information is available for the region being mapped. Correlation of results with actual data is encouraging although the accuracy of identification of specific crops from the single image is poor. The poor results can be partly attributed to only one image taken during mid-season when the three major crops were reflecting approximately the same and their ClR image appears to indicate the same crop type. However, some incapacity can be attributed to lack of understanding of the subtle variations of visual and infrared color reflectance of vegetation and surrounding environment. Analysis of integrated color variations of the vegetation and background environment recorded on ClR imagery is discussed. Problems associated with the color variations may be overcome by development of a semi-automatic processing system which considers individual field units or cells. Design criteria for semi-automatic processing system are outlined.

  4. [Estimation of adult mortality in six parishes of the central valley of Costa Rica (1888-1910) based on information on orphanhood].

    PubMed

    Jaspers Faijer, D; Perez Brignoli, H

    1985-04-01

    "This paper contains an application of the orphanhood method for estimating adult mortality, based on information provided during the period 1888-1910 by the brides and bridegrooms of six parishes of the Central Valley of Costa Rica.... Using the Brass technique for estimating adult mortality from orphanhood and interpolating the resulting probabilities of surviving into... Coale and Demeny's regional model life tables, the life expectancy at the age of 25 years is estimated [at] 41 years for women and 40 years for men." Mortality differences by region and social-occupational group are considered. (summary in ENG)

  5. A review of bioinformatics training applied to research in molecular medicine, agriculture and biodiversity in Costa Rica and Central America.

    PubMed

    Orozco, Allan; Morera, Jessica; Jiménez, Sergio; Boza, Ricardo

    2013-09-01

    Today, Bioinformatics has become a scientific discipline with great relevance for the Molecular Biosciences and for the Omics sciences in general. Although developed countries have progressed with large strides in Bioinformatics education and research, in other regions, such as Central America, the advances have occurred in a gradual way and with little support from the Academia, either at the undergraduate or graduate level. To address this problem, the University of Costa Rica's Medical School, a regional leader in Bioinformatics in Central America, has been conducting a series of Bioinformatics workshops, seminars and courses, leading to the creation of the region's first Bioinformatics Master's Degree. The recent creation of the Central American Bioinformatics Network (BioCANET), associated to the deployment of a supporting computational infrastructure (HPC Cluster) devoted to provide computing support for Molecular Biology in the region, is providing a foundational stone for the development of Bioinformatics in the area. Central American bioinformaticians have participated in the creation of as well as co-founded the Iberoamerican Bioinformatics Society (SOIBIO). In this article, we review the most recent activities in education and research in Bioinformatics from several regional institutions. These activities have resulted in further advances for Molecular Medicine, Agriculture and Biodiversity research in Costa Rica and the rest of the Central American countries. Finally, we provide summary information on the first Central America Bioinformatics International Congress, as well as the creation of the first Bioinformatics company (Indromics Bioinformatics), spin-off the Academy in Central America and the Caribbean.

  6. The Eastern Lower Tagus Valley Fault Zone in central Portugal: Active faulting in a low-deformation region within a major river environment

    NASA Astrophysics Data System (ADS)

    Canora, Carolina; Vilanova, Susana P.; Besana-Ostman, Glenda M.; Carvalho, João; Heleno, Sandra; Fonseca, Joao

    2015-10-01

    Active faulting in the Lower Tagus Valley, Central Portugal, poses a significant seismic hazard that is not well understood. Although the area has been affected by damaging earthquakes during historical times, only recently has definitive evidence of Quaternary surface faulting been found along the western side of the Tagus River. The location, geometry and kinematics of active faults along the eastern side of the Tagus valley have not been previously studied. We present the first results of mapping and paleoseismic analysis of the eastern strand of the Lower Tagus Valley Fault Zone (LTVFZ). Geomorphological, paleoseismological, and seismic reflection studies indicate that the Eastern LTVFZ is a left-lateral strike-slip fault. The detailed mapping of geomorphic features and studies in two paleoseismic trenches show that surface fault rupture has occurred at least six times during the past 10 ka. The river offsets indicate a minimum slip rate on the order of 0.14-0.24 mm/yr for the fault zone. Fault trace mapping, geomorphic analysis, and paleoseismic studies suggest a maximum magnitude for the Eastern LTVFZ of Mw ~ 7.3 with a recurrence interval for surface ruptures ~ 1.7 ka. At least two events occurred after 1175 ± 95 cal yr BP. Single-event displacements are unlikely to be resolved in the paleoseismic trenches, thus our observations most probably represent the minimum number of events identified in the trenches.

  7. 77 FR 18858 - Remanded Biological Opinions on the Coordinated Long-Term Operation of the Central Valley Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... Valley Project and State Water Project: Notice of Intent To Prepare an Environmental Impact Statement and... the State Water Project, that are likely to avoid jeopardy and destruction or adverse modification of... addressed and any other important issues related to the proposed action. DATES: Submit written comments...

  8. 75 FR 18499 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-12

    ... surface coal mining projects, in coordination with Federal and State regulatory agencies ( http://www.epa.gov/owow/wetlands/guidance/mining.html ). Both documents will be reviewed by an independent review...,'' is to assess the state of the science on the ecological impacts of Mountaintop Mining and Valley...

  9. Contaminant exposure of willets feeding in agricultural drainages of the Lower Rio Grande Valley of South Texas.

    PubMed

    Custer, T W; Mitchell, C A

    1991-02-01

    Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Laguna Madre of South Texas and at two other Texas coastal sites. Mean liver concentration of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in livers for all locations (means = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

  10. Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas

    USGS Publications Warehouse

    Custer, T.W.; Mitchell, C.A.

    1991-01-01

    Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Laguna Madre of South Texas and at two other Texas coastal sites. Mean liver concentration of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in livers for all locations (means = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

  11. Differences in instream wood characteristics between channelized and unchannelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Instream wood is an important resource for stream biota because it provides cover for fishes, substrate for macroinvertebrates, and increases habitat diversity. However, current management of instream wood within channelized agricultural headwater streams (drainage ditches) involves removing instrea...

  12. Agriculture has changed the amount and composition of dissolved organic matter in Central European headwater streams.

    PubMed

    Graeber, Daniel; Gelbrecht, Jörg; Pusch, Martin T; Anlanger, Christine; von Schiller, Daniel

    2012-11-01

    Dissolved organic matter (DOM) is an important part of the global carbon cycle and significantly influences aquatic ecosystem functions. Recent studies suggest that its amount and composition in freshwaters may be altered by agricultural land use, whereby the influence of preceding in-stream production and processing is not clear. To assess the land use effect on DOM amount and composition for the export from terrestrial to freshwater systems at the land-water interface, we sampled headwater streams draining agricultural and near-pristine catchments (forested and wetland) in the North German plains. To account for spatial and seasonal variation, we conducted a screening of DOM amount (53 sites) and composition (42 sites), and conducted bi-weekly samplings to investigate seasonal variation at eight sites over one year. Concentrations of dissolved organic carbon (DOC) were significantly higher for agricultural and wetland catchments than for forested catchments. Moreover, DOC loads exhibited higher seasonal variation for agricultural and wetland catchments than for forested catchments, which was due to higher variation in discharge. Parallel Factor Analysis revealed that the composition of DOM in agricultural catchments was significantly different from the other studied catchment types, and was characterized by low redox state and high structural complexity. Moreover, a gradient from protein- to humic-like fluorescence significantly separated forested from agricultural and wetland catchments. The contribution of humic-like DOM was strongly and positively related to DOC concentration, suggesting a mechanistic coupling of both. The effects of land use on patterns of DOC concentration and DOM composition were consistent across seasons, implying that land use strongly regulates DOM export. Overall, this study clearly shows the seasonally independent importance of agricultural land use for the amount and composition of DOM fluxes from the terrestrial zone to surface

  13. A reconnaissance study of the effect of irrigated agriculture on water quality in the Ogallala Formation, Central High Plains Aquifer

    USGS Publications Warehouse

    McMahon, Peter B.

    2000-01-01

    In 1998, the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program began a regional study of water quality in the High Plains aquifer. The High Plains aquifer underlies an area of about 174,000 square miles in parts of eight States. Because of its large size, the High Plains aquifer has been divided into three regions: the Southern High Plains, Central High Plains, and Northern High Plains (fig. 1A). Although an assessment of water quality in each of the three regions is planned, the initial focus will be the Central High Plains aquifer. Anyone who has flown over the Central High Plains in the summer and has seen the large green circles associated with center pivot sprinklers (fig. 2) knows that irrigated agriculture is a widespread land use. Pesticides and fertilizers applied on those irrigated fields will not degrade ground-water quality if they remain in or above the root zone (fig. 3). However, if those chemicals move downward through the unsaturated zone to the water table, they may degrade the quality of the ground water. Water is the principal agent for transporting chemicals from land surface to the water table, and in the semiarid Central High Plains, irrigation often represents the most abundant source of water during the growing season. One objective of NAWQA's High Plains Regional Ground-Water study is to evaluate the effect of irrigated agriculture on the quality of recently recharged water in the Ogallala Formation of the Central High Plains aquifer (figs. 1A and 1B). The Ogallala Formation is the principal geologic unit in the Central High Plains aquifer, and it consists of poorly sorted clay, silt, sand, and gravel that generally is unconsolidated (Gutentag and others, 1984). Approximately 23 percent of the cropland overlying the Ogallala Formation is irrigated (U.S. Department of Agriculture, 1999). The NAWQA Program generally defines recently recharged ground water to be water recharged in the last 50 years. The water table in

  14. The contribution of rice agriculture to methylmercury in surface waters: A review of data from the Sacramento Valley, California

    USGS Publications Warehouse

    Tanner, K. Christy; Windham-Myers, Lisamarie; Fleck, Jacob; Tate, Kenneth W.; McCord, Stephen A.; Linquist, Bruce A.

    2017-01-01

    Methylmercury (MeHg) is a bioaccumulative pollutant produced in and exported from flooded soils, including those used for rice (Oriza sativa L.) production. Using unfiltered aqueous MeHg data from MeHg monitoring programs in the Sacramento River watershed from 1996 to 2007, we assessed the MeHg contribution from rice systems to the Sacramento River. Using a mixed-effects regression analysis, we compared MeHg concentrations in agricultural drainage water from rice-dominated regions (AgDrain) to MeHg concentrations in the Sacramento and Feather Rivers, both upstream and downstream of AgDrain inputs. We also calculated MeHg loads from AgDrains and the Sacramento and Feather Rivers. Seasonally, MeHg concentrations were higher during November through May than during June through October, but the differences varied by location. Relative to upstream, November through May AgDrain least-squares mean MeHg concentration (0.18 ng L−1, range 0.15–0.23 ng L−1) was 2.3-fold higher, while June through October AgDrain mean concentration (0.097 ng L−1, range 0.6–1.6 ng L−1) was not significantly different from upstream. June through October AgDrain MeHg loads contributed 10.7 to 14.8% of the total Sacramento River MeHg load. Missing flow data prevented calculation of the percent contribution of AgDrains in November through May. At sites where calculation was possible, November through May loads made up 70 to 90% of the total annual load. Elevated flow and MeHg concentration in November through May both contribute to the majority of the AgDrain MeHg load occurring during this period. Methylmercury reduction efforts should target elevated November through May MeHg concentrations in AgDrains. However, our findings suggest that the contribution and environmental impact of rice is an order of magnitude lower than previous studies in the California Yolo Bypass.

  15. The Contribution of Rice Agriculture to Methylmercury in Surface Waters: A Review of Data from the Sacramento Valley, California.

    PubMed

    Tanner, K Christy; Windham-Myers, Lisamarie; Fleck, Jacob A; Tate, Kenneth W; McCord, Stephen A; Linquist, Bruce A

    2017-01-01

    Methylmercury (MeHg) is a bioaccumulative pollutant produced in and exported from flooded soils, including those used for rice ( L.) production. Using unfiltered aqueous MeHg data from MeHg monitoring programs in the Sacramento River watershed from 1996 to 2007, we assessed the MeHg contribution from rice systems to the Sacramento River. Using a mixed-effects regression analysis, we compared MeHg concentrations in agricultural drainage water from rice-dominated regions (AgDrain) to MeHg concentrations in the Sacramento and Feather Rivers, both upstream and downstream of AgDrain inputs. We also calculated MeHg loads from AgDrains and the Sacramento and Feather Rivers. Seasonally, MeHg concentrations were higher during November through May than during June through October, but the differences varied by location. Relative to upstream, November through May AgDrain least-squares mean MeHg concentration (0.18 ng L, range 0.15-0.23 ng L) was 2.3-fold higher, while June through October AgDrain mean concentration (0.097 ng L, range 0.6-1.6 ng L) was not significantly different from upstream. June through October AgDrain MeHg loads contributed 10.7 to 14.8% of the total Sacramento River MeHg load. Missing flow data prevented calculation of the percent contribution of AgDrains in November through May. At sites where calculation was possible, November through May loads made up 70 to 90% of the total annual load. Elevated flow and MeHg concentration in November through May both contribute to the majority of the AgDrain MeHg load occurring during this period. Methylmercury reduction efforts should target elevated November through May MeHg concentrations in AgDrains. However, our findings suggest that the contribution and environmental impact of rice is an order of magnitude lower than previous studies in the California Yolo Bypass.

  16. Budgets and chemical characterization of groundwater for the Diamond Valley flow system, central Nevada, 2011–12

    USGS Publications Warehouse

    Berger, David L.; Mayers, C. Justin; Garcia, C. Amanda; Buto, Susan G.; Huntington, Jena M.

    2016-07-29

    The pre-development, steady state, groundwater budget for the Diamond Valley flow system was estimated at about 70,000 acre-ft/yr of inflow and outflow. During years 2011–12, inflow components of groundwater recharge from precipitation and subsurface inflow from adjacent basins totaled 70,000 acre-ft/yr for the DVFS, whereas outflow components included 64,000 acre-ft/yr of groundwater evapotranspiration and 69,000 acre-ft/yr of net groundwater withdrawals, or net pumpage. Spring discharge in northern Diamond Valley declined about 6,000 acre-ft/yr between pre-development time and years 2011–12. Assuming net groundwater withdrawals minus spring flow decline is equivalent to the storage change, the 2011–12 summation of inflow and storage change was balanced with outflow at about 133,000 acre-ft/yr.

  17. Simulated effects of surface coal mining and agriculture on dissolved solids in the Redwater River, east-central Montana

    USGS Publications Warehouse

    Ferreira, R.F.; Lambing, J.H.

    1985-01-01

    Dissolved solids concentrations in five reaches of the Redwater River in east-central Montana were simulated to evaluate the effects of surface coal mining and agriculture. A mass-balance model of streamflow and dissolved solids load developed for the Tongue River in southeastern Montana was modified and applied to the Redwater River. Mined acreages, dissolved solids concentrations in mined spoils, and irrigated acreage can be varied in the model to study relative changes in the dissolved solids concentration in consecutive reaches of the river. Because of extreme variability and a limited amount of data, the model was not consecutively validated. Simulated mean and median monthly mean streamflows and consistently larger than those calculated from streamflow records. Simulated mean and median monthly mean dissolved solids loads also are consistently larger than regression-derived values. These discrepancies probably result from extremely variable streamflow, overestimates of streamflow from ungaged tributaries, and weak correlations between streamflow and dissolved solids concentrations. The largest increases in simulated dissolved solids concentrations from mining and agriculture occur from September through January because of smaller streamflows and dissolved solids loads. Different combinations of agriculture and mining under mean flow conditions resulted in cumulative percentage increases of dissolved solids concentrations of less than 5% for mining and less than 2% for agriculture. (USGS)

  18. Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York

    USGS Publications Warehouse

    Hayhurst, Brett; Kappel, William M.

    2014-01-01

    The Tully Valley, located in southern Onondaga County, New York, has a long history of unusual natural hydrogeologic phenomena including mudboils (Kappel, 2009), landslides (Tamulonis and others, 2009; Pair and others, 2000), landsurface subsidence (Hackett and others, 2009; Kappel, 2009), and a brine-filled sinkhole or “Solar pond” (fig. 1), which is documented in this report. A solar pond is a pool of salty water (brine) which stores the sun’s energy in the form of heat. The saltwater naturally forms distinct layers with increasing density between transitional zones (haloclines) of rapidly changing specific conductance with depth. In a typical solar pond, the top layer has a low salt content and is often times referred to as the upper convective zone (Lu and others, 2002). The bottom layer is a concentrated brine that is either convective or temperature stratified dependent on the surrounding environment. Solar insolation is absorbed and stored in the lower, denser brine while the overlying halocline acts as an insulating layer and prevents heat from moving upwards from the lower zone (Lu and others, 2002). In the case of the Tully Valley solar pond, water within the pond can be over 90 degrees Fahrenheit (°F) in late summer and early fall. The purpose of this report is to summarize observations at the Tully Valley brine-filled sinkhole and provide supplemental climate data which might affect the pond salinity gradients insolation (solar energy).

  19. Boundary of the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

    USGS Publications Warehouse

    Rupert, Michael G.; Plummer, L. Niel

    2009-01-01

    This vector data set delineates the approximate boundary of the Eagle River watershed valley-fill aquifer (ERWVFA). This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. The boundary of the ERWVFA was developed by combining information from two data sources. The first data source was a 1:250,000-scale geologic map of the Leadville quadrangle developed by Day and others (1999). The location of Quaternary sediments was used as a first approximation of the ERWVFA. The boundary of the ERWVFA was further refined by overlaying the geologic map with Digital Raster Graphic (DRG) scanned images of 1:24,000 topographic maps (U.S. Geological Survey, 2001). Where appropriate, the boundary of the ERWVFA was remapped to correspond with the edge of the valley-fill aquifer marked by an abrupt change in topography at the edge of the valley floor throughout the Eagle River watershed. The boundary of the ERWVFA more closely resembles a hydrogeomorphic region presented by Rupert (2003, p. 8) because it is based upon general geographic extents of geologic materials and not on an actual aquifer location as would be determined through a rigorous hydrogeologic investigation.

  20. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, M.K.; Green, C.T.; Belitz, K.; Singleton, M.J.; Esser, B.K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated gt;5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use. ?? 2011 Springer-Verlag (outside the USA).

  1. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3–N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  2. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-09-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  3. The effects of buffer strips and bioretention facilities on agricultural productivity and environmental quality in Central Africa

    NASA Astrophysics Data System (ADS)

    Gilroy, Kristin L.; McCuen, Richard H.

    2010-05-01

    SummaryLand degradation is a growing concern in Central Africa as poor management practices continue to cause erosion and increase water runoff in agricultural fields. The implementation of best management practices (BMPs) is needed; however, productivity is often indirectly related to the environmental benefits of such practices and resource constraints often exist. The purpose of this study was to determine the effects of bioretention facilities and buffer strips on environmental quality with productivity and resources as constraints. A water quantity and quality model for an agricultural field in Central Africa was developed. Analyses were conducted to assess the marginal benefits of each BMP, the effect of different BMP combinations on environmental quality and productivity, and the effect of data uncertainty and location uncertainty on model predictions. The results showed that bioretention pits were more effective than buffer strips in increasing environmental quality. Productivity was shown to be directly related to bioretention pits, thus environmental quality can be attained without sacrificing productivity. Data uncertainties resulted in changes in the environmental quality values, but trends remained the same. Guidelines were provided to assist design engineers in developing BMP scenarios that provide the greatest productivity and environmental quality for the constraints involved. The results of this study will bring awareness to the ability of attaining environmental quality without sacrificing productivity as well as the need for accurate data in Central Africa.

  4. Stratigraphy of the Arriaga Palaeolithic sites. Implications for the geomorphological evolution recorded by thickened fluvial sequences within the Manzanares River valley (Madrid Neogene Basin, Central Spain)

    NASA Astrophysics Data System (ADS)

    Silva, P. G.; López-Recio, M.; Tapias, F.; Roquero, E.; Morín, J.; Rus, I.; Carrasco-García, P.; Giner-Robles, J. L.; Rodríguez-Pascua, M. A.; Pérez-López, R.

    2013-08-01

    The Arriaga Palaeolithic sites, located within the Middle-Late Pleistocene thickened terrace (TCMZ: + 18-22 m) of the Manzanares River valley (Madrid, Central Spain), were subject to intensive archaeological and palaeontological prospecting during the 1980s. Compilation of documents from these old excavations, together with new geoarchaeological, sedimentological, pedological and geophysical data, allow us to locate the morpho-stratigraphic position of the analysed sites within the overall stratigraphy of the TCMZ. This thickened terrace comprises two main fluvial sequences (Lower and Upper) topped by a thick (2.5-5 m) alluvial-colluvial formation. The fluvial sequences are stacked in the study site located in the lowermost reach of the valley, but display complex inset relationships upstream, where they are individualized in two different terrace levels at + 18-22 and + 12-15 m. Terrace thickening was primarily controlled by synsedimentary subsidence caused by dissolution of the evaporitic substratum and locally influenced and backfed by tectonic activity. The regional analysis of the dated (TL and OSL) fluvial sequences containing Palaeolithic sites within the TCMZ, together with new TL dates provided in this study, indicate that the three sedimentary sequences in the TCMZ are time-transgressive valley-fill bodies. Terrace thickening started before the Last Interglacial Period (MIS 6 or older) and continued during whole MIS 5 (lower fluvial sequence) and MIS 4 (upper fluvial sequence) reaching the MIS 3 (top alluvial formation), the latter characterized by the accumulation of alluvial-colluvial sequences derived from the main tributaries and valley slopes. The TCMZ records the Middle-Late Pleistocene boundary, but also the transition between the Lower and Middle Palaeolithic periods during the Late MIS 5 (ca. 96 to 74 ka). The studied Arriaga sites contain evolved Lower Palaeolithic industry (evolved Acheulean techno-complexes) and warm faunal assemblages located

  5. GEODATA: Information System Based on Geospatial for Early Warning Tracking and Analysis Agricultural Plant Diseases in Central Java

    NASA Astrophysics Data System (ADS)

    Prasetyo, S. Y. J.; Agus, Y. H.; Dewi, C.; Simanjuntak, B. H.; Hartomo, K. D.

    2017-03-01

    The Government of Indonesia is currently faced with the problems of food, especially rice. It needs in large numbers that have to import from neighboring countries. Actually, the Indonesian government has the ability to produce rice to meet national needs but is still faced with the problem of pest attack rice annually increasing extent. One of the factors is that geographically Indonesia located on the migration path of world rice insect pests (called BPH or Brown Planthoppers) (Nilaparvata lugens Stal.) It leads endemic status annually. One proposed strategy to be applied is to use an early warning system based on a specific region of the main pest population. The proposed information system called GEODATA. GEODATA is Geospatial Outbreak of Disease Tracking and Analysis. The system works using a library ESSA (Exponential Smoothing - Spatial Autocorrelation) developed in previous studies in Satya Wacana Christian University. GEODATA built to meet the qualifications required surveillance device by BMKG (Indonesian Agency of Meteorology, Climatology and Geophysics’ Central Java Provinces), BPTPH (Indonesian Agency of Plant Protection and Horticulture) Central Java Provinces, BKP-KP District Boyolali, Central Java, (Indonesian Agency of Food Security and Agriculture Field Supervisor, District Boyolali, Central Java Provinces) and farmer groups. GIS GEODATA meets the needs of surveillance devices that include: (1) mapping of the disease, (2) analysis of the dynamics of the disease, and (3) prediction of attacks / disease outbreaks in a particular region. GIS GEODATA is currently under implementation in the laboratory field observations of plant pest in Central Java province, Indonesia.

  6. Agricultural management and greenhouse gas flux: cropland management in eastern and central US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural soils are the primary source of nitrous oxide (N2O) and a minor source of methane (CH4), two important biogenic greenhouse gases (GHG) that are contributing to catastrophic global climate change. Nitrous oxide emissions are expected to increase by 35-60% worldwide as pressure to increa...

  7. HLA class II alleles in the Otomi population of the Mezquital Valley: a genetic approach to the history of interethnic migrations in the Mexican Central Plateau.

    PubMed

    Juárez-Martín, Ana Itzel; González-Sobrino, Blanca Zoila; Olvera, Ángel Eduardo Camarena; Falfán-Valencia, Ramcés

    2014-01-01

    From a historical and genetic point of view, the Otomi of the Mezquital Valley are a frontier people that have played an important role in the population dynamics of the Mexican Central Plateau. Due to the antiquity of their presence in the area, the Otomi may be bearers of ancient genetic variability, shared mainly today with other groups belonging to the Otomanguean linguistic family and with the Nahua. In this study we analyzed the HLA class II allele frequencies reported in Mexican indigenous populations, in order to provide an intraregional-level historical perspective of the genetic relationships between the Otomi of the Mezquital Valley and indigenous populations from other regions of Mexico. We examined genetic variation in HLA-DRB1 and -DQB1 loci in 66 nonrelated individuals belonging to seven indigenous communities from the Ixmiquilpan municipality in the Mezquital Valley, in the State of Hidalgo, Mexico. The variability of the HLA-DRB1 gene among the Otomi of the Mezquital Valley was mainly concentrated in five alleles: -DRB1*08:02 (31.06%), -DRB1*04:07 (25.77%), -DRB1*14:06 (7.55%), -DRB1*14:02 (6.06%), and -DRB1*16:02 (4.55%); these alleles have been previously described in other indigenous populations. The most frequent alleles at the HLA-DQB1 locus were -DQB1*03:02 (34.09%), -DQB1*04:02 (31.03%), and -DQB1*03:01 (19.7%). Furthermore, the HLA-DQB1*02:02 allele was found in the Otomi group with a frequency of 2.27%; this allele has not been reported in Mexican indigenous populations. In conclusion, the genetic constitution of the Otomi population is intermediate to the northern groups and the genetic variability shared by the peoples of the central regions of Mexico. Furthermore, HLA-DRB1 and -DQB1 allelic variability among the Otomi provides insight into the historical processes implied in the biological admixture with European, Asian, and African populations as well as in the admixture with the population of Mexico City associated with long

  8. Co-creating Understanding in Water Use & Agricultural Resilience in a Multi-scale Natural-human System: Sacramento River Valley--California's Water Heartland in Transition

    NASA Astrophysics Data System (ADS)

    Fairbanks, D. H.; Brimlowe, J.; Chaudry, A.; Gray, K.; Greene, T.; Guzley, R.; Hatfield, C.; Houk, E.; Le Page, C.

    2012-12-01

    The Sacramento River Valley (SRV), valued for its $2.5 billion agricultural production and its biodiversity, is the main supplier of California's water, servicing 25 million people. . Despite rapid changes to the region, little is known about the collective motivations and consequences of land and water use decisions, or the social and environmental vulnerability and resilience of the SRV. The overarching research goal is to examine whether the SRV can continue to supply clean water for California and accommodate agricultural production and biodiversity while coping with climate change and population growth. Without understanding these issues, the resources of the SRV face an uncertain future. The defining goal is to construct a framework that integrates cross-disciplinary and diverse stakeholder perspectives in order to develop a comprehensive understanding of how SRV stakeholders make land and water use decisions. Traditional approaches for modeling have failed to take into consideration multi-scale stakeholder input. Currently there is no effective method to facilitate producers and government agencies in developing a shared representation to address the issues that face the region. To address this gap, researchers and stakeholders are working together to collect and consolidate disconnected knowledge held by stakeholder groups (agencies, irrigation districts, and producers) into a holistic conceptual model of how stakeholders view and make decisions with land and water use under various management systems. Our approach integrates a top-down approach (agency stakeholders) for larger scale management decisions with a conceptual co-creation and data gathering bottom-up approach with local agricultural producer stakeholders for input water and landuse decisions. Land use change models that combine a top-down approach with a bottom-up stakeholder approach are rare and yet essential to understanding how the social process of land use change and ecosystem function are

  9. Design of climate scenarios with application to agriculture and forestry in central and eastern north America. Final report

    SciTech Connect

    Lamb, P.J.; Richman, M.B.

    1996-06-01

    A research program supported by a USEPA cooperative agreement concentrated on statistical and climatological issues related to designing climate scenarios useful for agricultural and forestry in central and eastern North America. Results can be categorized into the areas of statistical techniques for scenario development and evaluation, climate system research, and data set development. A review of the meteorological use of clustering algorithms and an extensive comparison of cluster methods was undertaken. The last major methodological research was development of target analysis, which allows direct incorporation of climate scenarios into a data reduction and pattern matching algorithm. This was tested successfully on GCM output for realistic climate scenarios.

  10. Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

    USGS Publications Warehouse

    Bartolino, James R.

    2009-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through

  11. Climate change impacts on water availability: developing regional scenarios for agriculture of the Former Soviet Union countries of Central Asia

    NASA Astrophysics Data System (ADS)

    Kirilenko, A.; Dronin, N.

    2010-12-01

    Water is the major factor, limiting agriculture of the five Former Soviet Union (FSU) of Central Asia. Elevated topography prevents moist and warm air from the Atlantic and Indian Oceans from entering the region.With exception of Kazakhstan, agriculture is generally restricted to oases and irrigated lands along the major rivers and canals. Availability of water for irrigation is the major factor constraining agriculture in the region, and conflicts over water are not infrequent. The current water crisis in the region is largely due to human activity; however the region is also strongly impacted by the climate. In multiple locations, planned and autonomous adaptations to climate change have already resulted in changes in agriculture, such as a dramatic increase in irrigation, or shift in crops towards the ones better suited for warmer and dryer climate; however, it is hard to differentiate between the effects of overall management improvement and the avoidance of climate-related losses. Climate change will contribute to water problems, escalating irrigation demand during the drought period, and increasing water loss with evaporation. The future of the countries of the Aral Sea basin then depends on both the regional scenario of water management policy and a global scenario of climate change, and is integrated with global socioeconomic scenarios. We formulate a set of regional policy scenarios (“Business as Usual”, “Falling Behind” and “Closing the Gap”) and demonstrate how each of them corresponds to IPCC SRES scenarios, the latter used as an input to the General Circulation Models (GCMs). Then we discuss the relative effectiveness of the introduced scenarios for mitigating water problems in the region, taking into account the adaptation through changing water demand for agriculture. Finally, we introduce the results of multimodel analysis of GCM climate projections, especially in relation to the change in precipitation and frequency of droughts, and

  12. H. R. 3113: an act providing for the coordinated operation of the Central Valley project and the State water project in California. Introduced in the Senate of the United States, Ninety-Ninth Congress, Second Session, March 25, 1985

    SciTech Connect

    Not Available

    1986-01-01

    The House Committee on Energy and Natural Resources rewrote the Bill coordinating operations of the Central Valley Project in California and the state water project, and limited the Secretary of the Interior to no more than 75% of the Central Valley Project's annual yield. The Bill specifies procedures for water delivery contracts and reimbursements. Title II deals with the preservation of the Suisin Marsh District; Title III with the reclamation of small projects; and Title IV with contract validation. The document contains both the original and the amended wording of H.R. 3113.

  13. Airplane measurements above a patchy, agricultural dominated landscape in Central Europe

    NASA Astrophysics Data System (ADS)

    Schween, J. H.; Selbach, C.; Crewell, S.; Geiss, H.

    2009-04-01

    During the FLUXPAT campaign in 2008 the MetAir Dimona research aricraft performed several fligths above a patchy, agricultural dominated landscape near Juelich/Germany. Main focus of the measurements are variability of water vapor and CO2 and their turbulent fluxes in the atmospheric boundary layer close to the ground. Flights took place at changing levels between 80m and 400m above ground in legs parallel and perpendicular to the prevailing wind. Agriculture in the region is dominated by two different crops: sugar beet and wheat. Simultaneous to the flights measurements at the ground took place to determine evapotranspiration and CO2 uptake of the crops, single plants and the soil below. We will present analyses of the airborne concentration and flux measurements, identify organized structures or at least parameters characterizing them. These parameters are related to external parameters as wind, stability, boundary layer depth and and surface fluxes and their distribution on the ground.

  14. Digital tabulation of stratigraphic data from oil and gas wells in Cuyama Valley and surrounding areas, central California

    USGS Publications Warehouse

    Sweetkind, Donald S.; Bova, Shiera C.; Langenheim, V.E.; Shumaker, Lauren E.; Scheirer, Daniel S.

    2013-01-01

    Stratigraphic information from 391 oil and gas exploration wells from Cuyama Valley, California, and surrounding areas are herein compiled in digital form from reports that were released originally in paper form. The Cuyama Basin is located within the southeasternmost part of the Coast Ranges and north of the western Transverse Ranges, west of the San Andreas fault. Knowledge of the location and elevation of stratigraphic tops of formations throughout the basin is a first step toward understanding depositional trends and the structural evolution of the basin through time, and helps in understanding the slip history and partitioning of slip on San Andreas and related faults.

  15. Source rocks, thermal history and oil in the Carson Sink and Buena Vista Valley, west central Nevada

    SciTech Connect

    Barker, C.E.

    1995-06-01

    Rock-Eval, gas chromatography, mass spectrometry, and thermal history reconstruction data from six wells suggest that Tertiary rocks in the Carson Sink and Buena Vista Valley areas are marginally mature to overmature with respect to hydrocarbon generation and have locally expelled oil. The lacustrine Tertiary calcareous mudstones and marls in these wells have a total organic carbon (TOC) range from 0.1 to 3 wt.-%, with modes at about 0.5 to 0.7, 1.5, and 2 to 3 wt-% TOC. However, in the Standard Amoco Carson Sink 1 well, some of these samples have up to 3 wt-% less TOC than reported by Hastings (1979) and these are thought to represent drill cutting samples that have been depleted in more TOC rich rock chips. Even if the TOC data are biased, these TOC-depleted samples are still oil-prone rocks, with hydrogen indices commonly above 400 mg hydrocarbon/g C, and some samples with TOC in the 2-3 wt.-% range. Analysis of an oil show at Kyle Hot Springs in Buena Vista Valley revealed a wax-rich, low sulfur oil probably from a carbonate-rich, hypersaline lacustrine source rock. This oil could be generated from strata similar to those analyzed above. Other Tertiary source rocks in the two valleys consist of lenses of humic coals that appear to be gas prone. Shows of biogenic(?) gas from shallow wells in Tertiary to Holocene lacustrine strata are common in the Carson Sink. Mesozoic rocks locally may have remaining hydrocarbon generation potential in the Stillwater Range which lie along the eastern margin of the Carson Sink. Published conodont alteration index data shows that the Paleozoic rocks are overmature. Reconstructed thermal histories of the Carson Sink and Buena Vista Valley areas, indicate petroleum is presently being generated. Mechanisms for petroleum generation are rapid burial (140 m/m.y.) in a high geothermal gradient (45 to 110{degrees}C/km), and hydrothermal and contact metamorphism.

  16. A Decision Support System for Climate Change Adaptation in Rainfed Sectors of Agriculture for Central Europe

    NASA Astrophysics Data System (ADS)

    Mátyás, Csaba; Berki, Imre; Drüszler, Áron; Eredics, Attila; Gálos, Borbála; Illés, Gábor; Móricz, Norbert; Rasztovits, Ervin; Czimber, Kornél

    2013-04-01

    • Background and aims: Rainfed sectors of agriculture such as nature-close forestry, non-irrigated agriculture and animal husbandry on nature-close pastures are threatened by projected climate change especially in low-elevation regions in Southeast Europe, where precipitation is the limiting factor of production and ecosystem stability. Therefore the importance of complex, long term management planning and of land use optimization is increasing. The aim of the Decision Support System under development is to raise awareness and initiate preparation for frequency increase of extreme events, disasters and economic losses in the mentioned sectors. • Services provided: The Decision Support System provides GIS-supported information about the most important regional and local risks and mitigation options regarding climate change impacts, projected for reference periods until 2100 (e.g. land cover/use and expectable changes, potential production, water and carbon cycle, biodiversity and other ecosystem services, potential pests and diseases, tolerance limits etc.). The projections are referring first of all on biological production (natural produce), but the System includes also social and economic consequences. • Methods: In the raster based system, the latest image processing technology is used. We apply fuzzy membership functions, Support Vector Machine and Maximum Likelihood classifier. The System is developed in the first step for a reference area in SW Hungary (Zala county). • Novelty: The coherent, fine-scale regional system integrates the basic information about present and projected climates, extremes, hydrology and soil conditions and expected production potential for three sectors of agriculture as options for land use and conservation. • Funding: The development of the Decision Support System "Agrárklíma" is supported by TÁMOP-4.2.2.A-11/1/KONV and 4.2.2.B-10/1-2010-0018 "Talentum" joint EU-national research projects. Keywords: climate change

  17. West African and Amerindian ancestry and risk of myocardial infarction and metabolic syndrome in the Central Valley population of Costa Rica.

    PubMed

    Ruiz-Narváez, Edward A; Bare, Lance; Arellano, Andre; Catanese, Joseph; Campos, Hannia

    2010-06-01

    Genetic ancestry and environmental factors may contribute to the ethnic differences in risk of coronary heart disease (CHD), metabolic syndrome (MS) or its individual components. The population of the Central Valley of Costa Rica offers a unique opportunity to assess the role of genetic ancestry in these chronic diseases because it derived from the admixture of a relatively small number of founders of Southern European, Amerindian, and West African origin. We aimed to determine whether genetic ancestry is associated with risk of myocardial infarction (MI), MS and its individual components in the Central Valley of Costa Rica. We genotyped 39 ancestral informative markers in cases (n = 1,998) with a first non-fatal acute MI and population-based controls (n = 1,998) matched for age, sex, and area of residence, to estimate individual ancestry proportions. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using conditional (MI) and unconditional (MS and its components) logistic regression adjusting for relevant confounders. Mean individual ancestry proportions in cases and controls were 57.5 versus 57.8% for the Southern European, 38.4 versus 38.3% for the Amerindian and 4.1 versus 3.8% for the West African ancestry. Compared with Southern European ancestry, each 10% increase in West African ancestry was associated with a 29% increase in MI, OR (95% CI) = 1.29 (1.07, 1.56), and with a 30% increase on the risk of hypertension, OR (95% CI) = 1.30 (1.00, 1.70). Each 10% increase in Amerindian ancestry was associated with a 14% increase on the risk of MS, OR (95% CI) = 1.14 (1.00, 1.30), and 20% increase on the risk of impaired fasting glucose, OR (95% CI) = 1.20 (1.01, 1.42). These results show that the high variability of admixture proportions in the Central Valley population offers a unique opportunity to uncover the genetic basis of ethnic differences on the risk of disease.

  18. Agricultural Education. Proceedings of the Central Region Annual Research Conference (44th, Chicago, Illinois, February 24-25, 1990).

    ERIC Educational Resources Information Center

    Kansas State Univ., Manhattan.

    The following papers are included: "Focusing Agricultural Education Research" (Williams); "A Time Series Analysis of Agricultural Education Student Teachers' Perceptions of Agricultural Mechanics Laboratory Management Competencies" (Schumacher, Johnson); "Determination of the Agricultural Mechanics Laboratory Management Inservice Needs of Missouri…

  19. Comagmatic contact relationships between the Rock Creek Gabbro and Round Valley Peak granodiorite, central Sierra Nevada, CA

    SciTech Connect

    Christensen, C.C.; Bown, C.J. . School of Natural Science)

    1993-03-01

    The Rock Creek Gabbro (RCG) in Little Lakes Valley, near Tom's Place, CA abuts three granodiorites with distinctive contact characteristics. Against within a cm in most places. The contact with Round Valley Peak (RVP) on the north, however, is a zone at least 3 km wide and records a mode of mafic magmatic enclave formation. A northward traverse of the zone begins 300--400 m within the RCG with progressively lighter, though still uniform rock. Next is a 100--200m wide jumble of sharp-edged angular 10--30m gabbroic xenoliths, variable in grainsize and plastic deformation and interspersed with stretched partially disaggregated enclaves in normal RVP granodiorite. Xenoliths are essentially absent from the RVP from here north; stretched enclaves with very consistent strikes paralleling (within 20[degree]) the mapped RCG-RVP contact and high angle dips (70--90[degree]), occur singly and in dense swarms and fall from 4% to 0.5% of outcrop area in the remaining traverse. Rock Creek gabbros including xenoliths at the contact cluster chemically with RVP enclaves on all major and trace element plots, suggesting a common parentage; some of each group show evidence of plagioclase flotation. Trace element data (esp. Zr/Nb) suggests that fractional crystallization dominates mixing in the evolution of the gabbroic/enclave magma.

  20. Luminescence Dating of Sediments from the Luthern Valley, Central Switzerland, and Implications for the Chronology of the Last Glacial Cycle

    NASA Astrophysics Data System (ADS)

    Preusser, Frank; Müller, Benjamin U.; Schlüchter, Christian

    2001-03-01

    The advancing glaciers of the last glacial maximum either eroded or deeply buried older sediments in the Swiss Alpine Foreland. However, part of the Swiss Plateau was not covered by ice and is therefore an excellent area for investigating climate and environmental change during the Upper Pleistocene. Repeated fluvial sequences can be studied in several pits along the Luthern Valley. The chronological framework is based on lithostratigraphy, pollen analysis, U/Th dating, and, recently, heavy mineral analysis and luminescence dating. The oldest unit, the Untere Zeller Schotter braided river deposit, represents cold climate conditions and presumably a glaciation prior to the Eemian Interglaciation. The last interglacial period and the very beginning of the last glacial cycle is represented by the Mittlere Zeller Schotter, sediments of a meandering fluvial system. Younger braided river sediments, the Obere Zeller Schotter, seem to correlate with the cold climate of oxygen isotope stage (OIS) 4. Weathering of the top of the Obere Zeller Schotter is likely to represent the OIS 3. The advancing Reuss glacier caused erosion of the recent Luthern Valley, cutting into older sediments, with local loess accumulation during the last glacial maximum as indicated by cover sediments on top of the fluvial sequence.

  1. Quantifying the anthropogenic dust emission from agricultural land use and desiccation of the Aral Sea in Central Asia

    NASA Astrophysics Data System (ADS)

    Xi, Xin; Sokolik, Irina N.

    2016-10-01

    A regional dust model system is applied to quantify the anthropogenic dust emission in the post-Soviet Central Asia from 2000 to 2014. Two physically based dust schemes suggest that a proportion of 18.3-32.8% of total dust emissions is contributed by agricultural land use and the desiccation of Aral Sea, whereas a simplified dust scheme yields higher estimates in the range of 49.7-56.5% depending on whether a static or dynamic preferential dust source function is used. The dust schemes also differ greatly in the spatial distribution of anthropogenic dust and the sensitivity to the use of land use intensity in separating natural and human-made source areas, suggesting that the model representation of erosion threshold velocity, especially the role of vegetation, is a key source of model uncertainty in quantifying anthropogenic dust. The relative importance of agriculture and dried Aral Sea bed (Aralkum) differs greatly among the dust schemes. Despite the increased dust from the expansion of Aralkum, there is a negative trend in the anthropogenic dust proportion, indicating a shift of dust emission toward natural source areas. All dust schemes show a decrease in anthropogenic dust in response to land cover changes over agricultural lands.

  2. Prehistorically modified soils of central Amazonia: a model for sustainable agriculture in the twenty-first century.

    PubMed

    Glaser, Bruno

    2007-02-28

    Terra Preta soils of central Amazonia exhibit approximately three times more soil organic matter, nitrogen and phosphorus and 70 times more charcoal compared to adjacent infertile soils. The Terra Preta soils were generated by pre-Columbian native populations by chance or intentionally adding large amounts of charred residues (charcoal), organic wastes, excrements and bones. In this paper, it is argued that generating new Terra Preta sites ('Terra Preta nova') could be the basis for sustainable agriculture in the twenty-first century to produce food for billions of people, and could lead to attaining three Millennium Development Goals: (i) to combat desertification, (ii) to sequester atmospheric CO2 in the long term, and (iii) to maintain biodiversity hotspots such as tropical rainforests. Therefore, large-scale generation and utilization of Terra Preta soils would decrease the pressure on primary forests that are being extensively cleared for agricultural use with only limited fertility and sustainability and, hence, only providing a limited time for cropping. This would maintain biodiversity while mitigating both land degradation and climate change. However, it should not be overlooked that the infertility of most tropical soils (and associated low population density) is what could have prevented tropical forests undergoing large-scale clearance for agriculture. Increased fertility may increase the populations supported by shifting cultivation, thereby maintaining and increasing pressure on forests.

  3. Pesticide residues in leafy vegetables and human health risk assessment in North Central agricultural areas of Chile.

    PubMed

    Elgueta, Sebastian; Moyano, Stella; Sepúlveda, Paulina; Quiroz, Carlos; Correa, Arturo

    2017-06-01

    To investigate pesticide residue concentrations and potential human health risk, a study was conducted in 118 leafy vegetable samples collected in 2014-2015 from the North Central agricultural areas of Chile. The pesticide residues were determined using the multiresidue QuEChERS method by gas chromatography as well as high-performance liquid chromatography. The results indicated that 27% of the total samples contained pesticide residues above the maximum residue limits of each active ingredient. The maximum estimated daily intake obtained for carbon disulphide (CS2), methamidophos, azoxystrobin and cypermethrin were 0.57, 0.07, 0.06 and 0.05 mg kg(-1), respectively, which was higher than their acceptable daily intake. It is concluded that inhabitants of the North Central agricultural area of Chile are not exposed to health risks through the consumption of leafy vegetables with the exception of methamidophos. Nevertheless, the high levels of methamidophos detected in leafy vegetables could be considered a potential chronic health risk.

  4. The Population Structure of Phytophthora infestans from the Toluca Valley of Central Mexico Suggests Genetic Differentiation Between Populations from Cultivated Potato and Wild Solanum spp.

    PubMed

    Flier, Wilbert G; Grünwald, Niklaus J; Kroon, Laurens P N M; Sturbaum, Anne K; van den Bosch, Trudy B M; Garay-Serrano, Edith; Lozoya-Saldaña, Hector; Fry, William E; Turkensteen, Lod J

    2003-04-01

    ABSTRACT The population structure of Phytophthora infestans in the Toluca Valley of central Mexico was assessed using 170 isolates collected from cultivated potatoes and the native wild Solanum spp., S. demissum and S. xendinense. All isolates were analyzed for mitochondrial DNA (mtDNA) haplotype and amplified fragment length polymorphism (AFLP) multi-locus fingerprint genotype. Isolate samples were monomorphic for mtDNA haplotype because all isolates tested were of the Ia haplotype. A total of 158 multilocus AFLP genotypes were identified among the 170 P. infestans isolates included in this study. P. infestans populations sampled in the Toluca Valley in 1997 were highly variable and almost every single isolate represented a unique genotype based on the analysis of 165 AFLP marker loci. Populations of P. infestans collected from the commercial potato-growing region in the valley, the subsistence potato production area along the slopes of the Nevado de Toluca, and the native Solanum spp. on the forested slopes of the volcano showed a high degree of genetic diversity. The number of polymorphic loci varied from 20.0 to 62.4% for isolates collected from the field station and wild Solanum spp. On average, 81.8% (135) of the AFLP loci were polymorphic. Hetero-zygosity varied between 7.7 and 19.4%. Significant differentiation was found at the population level between strains originating from cultivated potatoes and wild Solanum spp. (P = 0.001 to 0.022). Private alleles were observed in individual isolates collected from all three populations, with numbers of unique dominant alleles varying from 9 to 16 for isolates collected from commercial potato crops and native Solanum spp., respectively. Four AFLP markers were exclusively found present in isolates collected from S. demissum. Indirect estimation of gene flow between populations indicated restricted gene flow between both P. infestans populations from cultivated potatoes and wild Solanum hosts. There was no evidence

  5. Agricultural Producer Perceptions of Climate Change and Climate Education Needs for the Central Great Plains

    ERIC Educational Resources Information Center

    Hibbs, Amber Campbell; Kahl, Daniel; PytlikZillig, Lisa; Champion, Ben; Abdel-Monem, Tarik; Steffensmeier, Timothy; Rice, Charles W.; Hubbard, Kenneth

    2014-01-01

    The Central Great Plains Climate Education Partnership conducted focus groups throughout Kansas to gain a better understanding of farmer perceptions and attitudes towards climate change education. Results indicate concern about climatic changes, even if producers are unsure that "human caused climate change" is occurring. Participants…

  6. Planting the Seeds of a New Agriculture: Living with the Land in Central America.

    ERIC Educational Resources Information Center

    Adriance, Jim

    1995-01-01

    Central America's macroeconomics, land tenure patterns, and population growth are forcing small-scale farmers to alternatives based on farmer-to-farmer teaching and farming in concert with the environment. Discusses major schools of thought that have fueled this phenomenon, and how extension services and isolated groups are joining to form a…

  7. A regression model for the temporal development of soil pipes and associated gullies in the alluvial-fill valley of the Rio Puerco, central New Mexico

    NASA Technical Reports Server (NTRS)

    Condit, C. D.; Elston, W. E.

    1984-01-01

    On Mars, the association of gullied escarpments and chaotic terrain is evidence for failure and scarp retreat of poorly consolidated materials. Some martian gullies have no surface outlets and may have drained through subterranean channels. Similar features, though on a much smaller scale, can be seen in alluvium along terrestrial river banks in semiarid regions, such as the Rio Puerco Valley of central New Mexico. Many of the escarpments along the Rio Puerco are developing through formation of collapse gullies, which drain through soil pipes. Gully development can be monitored on aerial photographs taken in 1935, 1962, and 1980. A regression model was developed to quantify gully evolution over a known time span. Soil pipes and their associated collapse gullies make recognizable signatures on the air photos. The areal extent of this signature can be normalized to the scarp length of each pipe-gully system, which makes comparisons between systems possible.

  8. Late Pleistocene Terraces in River Valleys of the Central Russian Plain: Morphology, Structure and History of Development

    NASA Astrophysics Data System (ADS)

    Matlakhova, Ekaterina; Panin, Andrey

    2014-05-01

    Morphology and sedimentary composition of low terraces of the Seim (the middle Dnieper catchment) and Khoper (the middle Don catchment) rivers were studied in the field (DGPS topographic profiling, hand and mechanical coring, examination of natural exposures) and in laboratory (grain size analysis, spore-pollen composition, 14C and OSL dating, microscopic study of quartz grains). Archaeological data have also been taken into account. It was found that Late Pleistocene river terraces were subject to complex reworking after the alluvial sedimentation had finished. Terraces may therefore contain sediments of different origin and terrace levels may vary according to the post-alluvial reworking. To establish terrace sedimentation mechanisms we supplemented lithological data collected in the field with quartz grains morphoscopy technique - microscopic study of quartz grains surfaces. The results exhibit wide participation of aeolian and slope wash sediments in terrace deposits, deep aeolian reworking of terrace alluvium during LGM that could be possible due to ground water lowering because of deep pre-LGM incision of rivers. The main difficulty in interpretation of morphoscopic results is that aeolian signals are sometimes not clear due to short duration of wind action over alluvial sands. River incision was detected within the interval since 50-60 to 25-30 ka BP (cal). High runoff increase is proposed as the reason of this incision, which is illustrated by formation of "big meanders" (macromeanders) in river valleys. There were probably several time spans of high runoff divided by low runoff intervals. By the time of LGM rivers had already been incised down to the modern river levels or deeper. The cryoaridic LGM time (20-23 ka BP cal) makes the most pronounced low runoff interval. After LGM, the last high runoff epoch started, which is dated to 13-18(19) ka BP (cal). Numerous now relict macromeanders were formed in river valleys at that time and considerable portions

  9. Regional Evaluation of Groundwater Age Distributions Using Lumped Parameter Models with Large, Sparse Datasets: Example from the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Jurgens, B. C.; Bohlke, J. K.; Voss, S.; Fram, M. S.; Esser, B.

    2015-12-01

    Tracer-based, lumped parameter models (LPMs) are an appealing way to estimate the distribution of age for groundwater because the cost of sampling wells is often less than building numerical groundwater flow models sufficiently complex to provide groundwater age distributions. In practice, however, tracer datasets are often incomplete because of anthropogenic or terrigenic contamination of tracers, or analytical limitations. While age interpretations using such datsets can have large uncertainties, it may still be possible to identify key parts of the age distribution if LPMs are carefully chosen to match hydrogeologic conceptualization and the degree of age mixing is reasonably estimated. We developed a systematic approach for evaluating groundwater age distributions using LPMs with a large but incomplete set of tracer data (3H, 3Hetrit, 14C, and CFCs) from 535 wells, mostly used for public supply, in the Central Valley, California, USA that were sampled by the USGS for the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment or the USGS National Water Quality Assessment Programs. In addition to mean ages, LPMs gave estimates of unsaturated zone travel times, recharge rates for pre- and post-development groundwater, the degree of age mixing in wells, proportion of young water (<60 yrs), and the depth of the boundary between post-development and predevelopment groundwater throughout the Central Valley. Age interpretations were evaluated by comparing past nitrate trends with LPM predicted trends, and whether the presence or absence of anthropogenic organic compounds was consistent with model results. This study illustrates a practical approach for assessing groundwater age information at a large scale to reveal important characteristics about the age structure of a major aquifer, and of the water supplies being derived from it.

  10. 76 FR 16818 - Central Valley Project Improvement Act, Standard Criteria for Ag and Urban Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... ``Standard Criteria for Agricultural and Urban Water Management Plans'' (Criteria) are now available for... published the Criteria. The Criteria apply to any Water Management Plans (Plans) submitted to Reclamation as... Management Plans are considered the same as Water Conservation Plans. DATES: Submit written comments by...

  11. Transient fluvial incision and spatial distribution of active rock uplift in the Uspallata-Calingasta-Iglesia Valley, Central Argentina.

    NASA Astrophysics Data System (ADS)

    Val, P.; Hoke, G. D.

    2014-12-01

    In the southern portion of the Pampean flat-slab subduction zone, a narrow, elongate intermontane depression separates the Precordillera fold-and-thrust belt from the Frontal and Principal Cordilleras of the high Andes. This depression, the Uspallata-Callingasta-Iglesia Valley, is divided into three catchments based on drainage divides between three large, transverse rivers. These catchments have their headwaters in the western Precordillera, Frontal Cordillera and Principal Cordillera ranges. Deformation is thought to have ceased near the core of the range (Frontal and Principal Cordilleras) and propagated to the east during the Miocene to present. In this study, river profiles and knickpoint topographic data are assessed to determine the distribution of active rock uplift and amount of fluvial incision in the Calingasta and Iglesia valleys. Slope-area data extracted from a digital elevation model consistently show slope-break knickpoints separating distinct sections of river profiles, which suggests relative bedrock uplift. Catchment-wide, normalized steepness indices (ksn) - using a concavity index of 0.45 (common in steady state profiles in the study area) - for both basins revealed consistently high ksn signals (>300) in the main stems and tributaries draining the Frontal Cordillera and the western Precordillera. The highest ksn values are situated in an elevation range of 2500 to 4000 m, west of the fold and thrust belt in the Principal and Frontal Cordilleras. Slope-break knickpoints are not clustered in elevation and there is no obvious correlation between upstream drainage area at knickpoints and respective distance from the tributaries' mouths, which suggests that they are not part of an upstream migrating wave of knickpoints. The data presented here indicate active rock uplift in the eastern edge of the Frontal Cordillera, which was previously considered inactive.

  12. An 11 000-year-long record of fire and vegetation history at Beaver Lake, Oregon, central Willamette Valley

    USGS Publications Warehouse

    Walsh, Megan K.; Pearl, Christopher A.; Whitlock, Cathy; Bartlein, Patrick J.; Worona, Marc A.

    2010-01-01

    High-resolution macroscopic charcoal and pollen analysis were used to reconstruct an 11??000-year-long record of fire and vegetation history from Beaver Lake, Oregon, the first complete Holocene paleoecological record from the floor of the Willamette Valley. In the early Holocene (ca 11??000-7500 calendar years before present [cal??yr??BP]), warmer, drier summers than at present led to the establishment of xeric woodland of Quercus, Corylus, and Pseudotsuga near the site. Disturbances (i.e., floods, fires) were common at this time and as a result Alnus rubra grew nearby. High fire frequency occurred in the early Holocene from ca 11??200-9300??cal??yr??BP. Riparian forest and wet prairie developed in the middle Holocene (ca 7500??cal??yr??BP), likely the result of a decrease in the frequency of flooding and a shift to effectively cooler, wetter conditions than before. The vegetation at Beaver Lake remained generally unchanged into the late Holocene (from 4000??cal??yr??BP to present), with the exception of land clearance associated with Euro-American settlement of the valley (ca 160??cal??yr BP). Middle-to-late Holocene increases in fire frequency, coupled with abrupt shifts in fire-episode magnitude and charcoal composition, likely indicate the influence anthropogenic burning near the site. The paleoecological record from Beaver Lake, and in particular the general increase in fire frequency over the last 8500??years, differs significantly from other low-elevation sites in the Pacific Northwest, which suggests that local controls (e.g., shifts in vegetation structure, intensification of human land-use), rather than regional climatic controls, more strongly influenced its environmental history. ?? 2010 Elsevier Ltd.

  13. An 11 000-year-long record of fire and vegetation history at Beaver Lake, Oregon, central Willamette Valley

    NASA Astrophysics Data System (ADS)

    Walsh, Megan K.; Pearl, Christopher A.; Whitlock, Cathy; Bartlein, Patrick J.; Worona, Marc A.

    2010-05-01

    High-resolution macroscopic charcoal and pollen analysis were used to reconstruct an 11 000-year-long record of fire and vegetation history from Beaver Lake, Oregon, the first complete Holocene paleoecological record from the floor of the Willamette Valley. In the early Holocene (ca 11 000-7500 calendar years before present [cal yr BP]), warmer, drier summers than at present led to the establishment of xeric woodland of Quercus, Corylus, and Pseudotsuga near the site. Disturbances (i.e., floods, fires) were common at this time and as a result Alnus rubra grew nearby. High fire frequency occurred in the early Holocene from ca 11 200-9300 cal yr BP. Riparian forest and wet prairie developed in the middle Holocene (ca 7500 cal yr BP), likely the result of a decrease in the frequency of flooding and a shift to effectively cooler, wetter conditions than before. The vegetation at Beaver Lake remained generally unchanged into the late Holocene (from 4000 cal yr BP to present), with the exception of land clearance associated with Euro-American settlement of the valley (ca 160 cal yr BP). Middle-to-late Holocene increases in fire frequency, coupled with abrupt shifts in fire-episode magnitude and charcoal composition, likely indicate the influence anthropogenic burning near the site. The paleoecological record from Beaver Lake, and in particular the general increase in fire frequency over the last 8500 years, differs significantly from other low-elevation sites in the Pacific Northwest, which suggests that local controls (e.g., shifts in vegetation structure, intensification of human land-use), rather than regional climatic controls, more strongly influenced its environmental history.

  14. Shallow ground-water quality in selected agricultural areas of south-central Georgia, 1994

    USGS Publications Warehouse

    Crandall, C.A.

    1996-01-01

    The Georgia-Florida Coastal Plain National Water-Quality Assessment Program began an agricultural land-use study in March 1994. The study area is located in the upper Suwannee River basin in Tift, Turner, Worth, Irwin, Wilcox, and Crisp Counties, Ga. Twenty-three shallow monitoring wells were installed in a 1,335-square- mile area characterized by intensive row-crop agriculture (peanuts, corn, cotton, and soybeans). The study focused on recently recharged shallow ground water in surficial aquifers to assess the relation between land-use activities and ground- water quality. All wells were sampled in March and April (spring) 1994, and 14 of these wells were resampled in August (summer) 1994. Shallow ground water in the study area is characterized by oxic and acidic conditions, low bicarbonate, and low dissolved-solids concentrations. The median pH of shallow ground water was 4.7 and the median bicarbonate concentration was 1.7 mg/L (milligrams per liter). Dissolved oxygen concentrations ranged from 3.0 to 8.0 mg/L. The median dissolved-solids concentration in samples collected in the spring was 86 mg/L. Major inorganic ion composition was generally mixed with no dominant cation; nitrate was the dominant anion (greater than 60 percent of the anion composition) in 14 of 23 samples. Only concentrations of bicarbonate, dissolved organic carbon, and nitrate had significant differences in conce