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Sample records for central valley of california

  1. Alluvial Boundary of California's Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the extent of the alluvial deposits in the Central Valley of California and encompasses the contiguous Sacramento, San Joaquin, and...

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

    Science.gov (United States)

    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)

  3. Spring 1961 water table of California's Central Valley (from Williamson and others, 1989)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the spring 1961 water-table altitude for the California's Central Valley. It was used to initiate the water-level altitudes for the...

  4. Recent landscape change in California's Central Valley

    Science.gov (United States)

    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.

  5. Geodatabase of the datasets used to represent the two subunits of the Central Valley aquifer system, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geodatabase includes spatial datasets that represent the Central Valley aquifer system in the State of California. Included are: (1) polygon extents; datasets...

  6. Spring 1961 hydraulic head in the lower pumped zone of California's Central Valley (from Williamson and others, 1989)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the spring 1961 hydraulic head in the lower pumped zone of California's Central Valley. It was used to initiate the water-level...

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

    Science.gov (United States)

    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.

  8. Satellites measure recent rates of groundwater depletion in California's Central Valley

    Science.gov (United States)

    Famiglietti, J. S.; Lo, M.; Ho, S. L.; Bethune, J.; Anderson, K. J.; Syed, T. H.; Swenson, S. C.; de Linage, C. R.; Rodell, M.

    2011-02-01

    In highly-productive agricultural areas such as California's Central Valley, where groundwater often supplies the bulk of the water required for irrigation, quantifying rates of groundwater depletion remains a challenge owing to a lack of monitoring infrastructure and the absence of water use reporting requirements. Here we use 78 months (October, 2003-March, 2010) of data from the Gravity Recovery and Climate Experiment satellite mission to estimate water storage changes in California's Sacramento and San Joaquin River Basins. We find that the basins are losing water at a rate of 31.0 ± 2.7 mm yr-1 equivalent water height, equal to a volume of 30.9 km3 for the study period, or nearly the capacity of Lake Mead, the largest reservoir in the United States. We use additional observations and hydrological model information to determine that the majority of these losses are due to groundwater depletion in the Central Valley. Our results show that the Central Valley lost 20.4 ± 3.9 mm yr-1 of groundwater during the 78-month period, or 20.3 km3 in volume. Continued groundwater depletion at this rate may well be unsustainable, with potentially dire consequences for the economic and food security of the United States.

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

    Science.gov (United States)

    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

  10. Indications for Protacted Groundwater Depletion after Drought over the Central Valley of California

    OpenAIRE

    Wang, S.-Y. Simon; Lin, Yen-Heng; Gillies, Robert R.; Hakala, Kirsti

    2015-01-01

    Ongoing (2014-2015) drought in the state of California has played a major 10 role in the depletion of groundwater. Within California’s Central Valley, home to one 11 of the world’s most productive agricultural regions, drought and increased 12 groundwater depletion occurs almost hand-in-hand but this relationship appears to 13 have changed over the last decade. Data derived from 497 wells have revealed a 14 continued depletion of groundwater lasting a full year after drought, a phenomenon 15 ...

  11. Economic and Water Supply Effects of Ending Groundwater Overdraft in California's Central Valley

    OpenAIRE

    Nelson, Timothy; Chou, Heidi; Zikalala, Prudentia; Lund, Jay; Hui, Rui; Medellín–Azuara, Josué

    2016-01-01

    doi: http://dx.doi.org/10.15447/sfews.2016v14iss1art7 Surface water and groundwater management are often tightly linked, even when linkage is not intended or expected. This link is especially common in semi-arid regions, such as California. This paper summarizes a modeling study on the effects of ending long-term overdraft in California’s Central Valley, the state’s largest aquifer system. The study focuses on economic and operational aspects, such as surface water pumping ...

  12. Effects of prescribed fires on young valley oak trees at a research restoration site in the Central Valley of California

    OpenAIRE

    Holmes, K A; Veblen, Kari E.; T. P. YOUNG; Berry, A. M.

    2011-01-01

    Woodland restoration sites planted with Quercus lobata (valley oak) often have serious invasions of nonnative annual grasses and thistles. Although prescribed fire can effectively control these exotics, restoration managers may be reluctant to use fire if it causes substantial mortality of recently planted saplings. We studied the effects of prescribed fires on the survival and subsequent growth of 5- and 6-year-old valley oak saplings at a research field near Davis, California. One set of bl...

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

    Science.gov (United States)

    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.

  14. A comparison of groundwater storage using GRACE data, groundwater levels, and a hydrological model in California's Central Valley

    Science.gov (United States)

    Floyd, B.; Kuss, A. M.; Brandt, W. T.; Randall, J. N.; Bourai, A.; Newcomer, M. E.; Schmidt, C.; Skiles, J. W.

    2011-12-01

    The Gravity Recovery and Climate Experiment (GRACE), a NASA satellite sensor, measures changes in total water storage (TWS) and may provide additional insight to the use of well-based data in California's Central Valley, an important agricultural 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 must be used. GRACE was used to map changes in TWS between October 2002 and September 2009 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. Downscaling GRACE data into 21 smaller Central Valley sub-regions included in C2VSIM was also evaluated. This work has the potential to improve California's groundwater measurements and existing hydrological models for the Central Valley.

  15. Assessment of Climate Change Impacts on Agricultural Water Demands and Crop Yields in California's Central Valley

    Science.gov (United States)

    Tansey, M. K.; Flores-Lopez, F.; Young, C. A.; Huntington, J. L.

    2012-12-01

    Long term planning for the management of California's water resources requires assessment of the effects of future climate changes on both water supply and demand. Considerable progress has been made on the evaluation of the effects of future climate changes on water supplies but less information is available with regard to water demands. Uncertainty in future climate projections increases the difficulty of assessing climate impacts and evaluating long range adaptation strategies. Compounding the uncertainty in the future climate projections is the fact that most readily available downscaled climate projections lack sufficient meteorological information to compute evapotranspiration (ET) by the widely accepted ASCE Penman-Monteith (PM) method. This study addresses potential changes in future Central Valley water demands and crop yields by examining the effects of climate change on soil evaporation, plant transpiration, growth and yield for major types of crops grown in the Central Valley of California. Five representative climate scenarios based on 112 bias corrected spatially downscaled CMIP 3 GCM climate simulations were developed using the hybrid delta ensemble method to span a wide range future climate uncertainty. Analysis of historical California Irrigation Management Information System meteorological data was combined with several meteorological estimation methods to compute future solar radiation, wind speed and dew point temperatures corresponding to the GCM projected temperatures and precipitation. Future atmospheric CO2 concentrations corresponding to the 5 representative climate projections were developed based on weighting IPCC SRES emissions scenarios. The Land, Atmosphere, and Water Simulator (LAWS) model was used to compute ET and yield changes in the early, middle and late 21st century for 24 representative agricultural crops grown in the Sacramento, San Joaquin and Tulare Lake basins. Study results indicate that changes in ET and yield vary

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  19. Fluxes of BVOC and tropospheric ozone from a Citrus orchard in the California Central Valley

    Science.gov (United States)

    Fares, S.; Park, J.; Weber, R.; Gentner, D. R.; Karlik, J. F.; Goldstein, A. H.

    2011-12-01

    Citrus plants, especially oranges, are widely cultivated in many countries experiencing Mediterranean climates. In many of these areas, orchards are often exposed to high levels of tropospheric ozone (O3) due to their location in polluted airsheds. Citrus take up O3 through their stomata and emit biogenic volatile organic compounds (BVOC), which can contribute to non-stomatal O3 removal through fast gas-phase reactions with O3. The study was performed in a valencia orange orchard in Exeter, California. From fall 2009 to winter 2010, CO2 & water fluxes, together with O3 uptake and BVOC emissions were measured continuously in situ with specific sensors (e.g. fast ozone analyzer and Proton Transfer Reaction Mass Spectrometer) using the eddy covariance techniques. Vertical concentration gradients of these compounds were also measured at 4 heights from the orchard floor to above the canopy. We observed high levels (up to 60 ppb) of volatile organic compounds including methanol, isoprene, monoterpenes, sesquiterpenes, and some additional oxygenated BVOC. Methanol dominated BVOC emissions (up to 7 nmol m-2 s-1) followed by acetone. Monoterpenes fluxes were also recorded during the all vegetative period, with the highest emissions taking place during flowering periods, and in general highly temperature dependent. The orchard represented a sink for ozone, with uptake rates on the order of 10 nmol m-2 s-1 during the central hours of the day. We found that BVOC played a major role in removing ozone through chemical reactions in the gas-phase, while only up to 40 % of ozone was removed via stomatal uptake. The current research aimed at investigating the fate of BVOC emitted from orange trees will help understanding the role of Citrus orchards in the complex oxidation mechanisms taking place in the polluted atmosphere of the San Joaquin Valley (California).

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-12-01

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. The ammonium nitrate particle equivalent of NOx emissions for wintertime conditions in Central California's San Joaquin Valley

    International Nuclear Information System (INIS)

    A new method has been developed to assess the aerosol particle formation reactivity of nitrogen oxide (NOx) emissions. The method involves using a photochemical box model with gas-phase photochemistry, aerosol production and deposition to calculate the ammonium nitrate particle equivalent of NOx emissions. The yields of ammonium nitrate particles used in the box model were determined from parametric simulations made with an equilibrium model that calculated the fraction of nitric acid that reacts to produce ammonium nitrate from the temperature, relative humidity and ammonium-to-nitrate ratios. For the wintertime conditions of emissions and meteorology in the San Joaquin Valley of central California, approximately 80% of the moles of nitric acid produced was found to be in the particulate nitrate phase and about 33% of the moles of emitted NOx was converted to particulate nitrate. The particle equivalent of NOx emissions was found to be on the order of 0.6 g of ammonium nitrate for each gram of NOx emitted (the mass of NOx calculated as NO2). This estimate is in reasonable agreement with an analysis of field measurements made in central California. (author)

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

    Science.gov (United States)

    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

  8. Compilation of data for isotope mapping of groundwater in the Central Valley of California, 1993-1995

    International Nuclear Information System (INIS)

    A major stable isotope mapping project is underway that will provide important baseline information to the State of California in management of their groundwater resources. The results represent a new technological application using isotope hydrology to better understand and predict the sustainability of California's groundwater supply for the future. This project is driven by the fact that Californians inhabit a semi-arid region of seasonal precipitation, but have created a lifestyle and economic infrastructure requiring a sub-tropical climate. They have accomplished this by engineering systems that store and divert alpine runoff, and by utilizing a large, productive alluvial aquifer. In the past, both of these resources appeared to be unlimited. Today, water shortages are recognized, regardless of drought conditions. Because Californians maintain their current practices of prolific water use, the deep-seated competition between agricultural users and urban consumers has been amplified. This has been aggravated by the acquisition of one-third of the available surface water resources for maintenance of aquatic habitats. The State of California accepts and encourages the use of groundwater to supplement these diverse water demands. Stable isotope imaging of the groundwater resources has proven to be the most economical and effective means to diagnose the health of the giant alluvial aquifer of the Central Valley. Augmented by radiocarbon analysis and nitrate determinations, stable isotope data can be used to clearly distinguish groundwater recharged from natural or anthropogenic sources. Isotope maps delineate (1) the geographic distribution of various groundwater masses and of preferential recharge zones, (2) the sources and extent of non-point source pollution, and (3) the locations and rates of lateral flow channels. Different recharge rates of natural and modem groundwater bodies can be used to characterize safe yield parameters for aquifers

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

    International Nuclear Information System (INIS)

    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 δ18O 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 18O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low 18O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in δ18O 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 ∼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 ∼40 years, creating cones of depression ∼25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low 18O water (-11.0 per-thousand) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp 18O gradients in our groundwater isotope map

  10. Denitrification in a Shallow Aquifer Underlying a Dairy Farm in the Central Valley of California

    Science.gov (United States)

    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

  11. Anthropogenic and Geologic Influence on the Downstream Fining Pattern of the Cosumnes River, Central Valley, California

    Science.gov (United States)

    Fehr, C. R.; Mount, J. F.

    2001-05-01

    A geomorphic survey of the Cosumnes River was conducted to identify the effects of anthropogenic change and local geology on downstream changes in grain size. Patterns of downstream fining exhibited by alluvial rivers reflect the processes of abrasion and sediment sorting by selective entrainment, transport and deposition. Longitudinal sorting of gravel is commonly modeled as a downstream exponential decrease in median particle grain size over the length of the profile. This relationship mirrors downstream reduction in gradient and bed shear stress typical of aggrading alluvial channels and is influenced by variations in sediment supply. The impacts of anthropogenic activity on these variables should be reflected by departures in downstream fining patterns from the expected trend. Results from this study show that grain-size change over the longitudinal profile deviates significantly from the predicted model. In addition, grain-size measurements at cross-sections demonstrate poor correlation with average bankfull bed shear stress. At sites where grain size appears unrelated to distance downstream as well as to energy slope, sediment transport may be directly influenced by alterations to the channel such as in-stream mining and the construction of diversion dams. Fluvial response to the cumulative effects of watershed-scale anthropogenic activities has also contributed to the modification of the nature of sediment transport in the channel. Prior to settlement of the Great Valley, the Cosumnes was a shallow, anastomosing alluvial river connected to a broad floodplain. Changes in land-use practices as well as channel regulation have caused rapid river-bed degradation and incision into resistant Quaternary alluvial fan deposits in some locations. Unlike the alluvial reaches studied, those with duripan beds and banks are characterized by a step-pool-like structure and contribute only small volumes of coarse sediment to the river. Data suggest that sediment transport in

  12. Irrigation in California's Central Valley strengthens the southwestern U.S. water cycle

    OpenAIRE

    Lo, Min-Hui; Famiglietti, James S

    2013-01-01

    Characterizing climatological and hydrological responses to agricultural irrigation continues to be an important challenge to understanding the full impact of water management on the Earth's environment and hydrological cycle. In this study, we use a global climate model, combined with realistic estimates of regional agricultural water use, to simulate the local and remote impacts of irrigation in California's Central Valley. We demonstrate a clear mechanism that the resulting increase in eva...

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

    Science.gov (United States)

    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

  14. Evaluation of pesticides in vernal pools of the Central Valley, California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Vernal pools are a unique ephemeral wetland feature of California’s native landscape which has been heavily impacted over the past century by agricultural and urban...

  15. Research Spotlight: Groundwater is being depleted rapidly in California's Central Valley

    Science.gov (United States)

    Tretkoff, Ernie

    2011-03-01

    Groundwater is being depleted in California's Central Valley at a rapid rate, according to data from the Gravity Recovery and Climate Experiment (GRACE) satellite. Famiglietti et al. analyzed 78 months of GRACE data covering October 2003 to March 2010 to estimate water storage changes in California's Sacramento and San Joaquin river basins. They found that the basins are losing water at a rate of about 30 millimeters per year equivalent water height, or a total of about 30 cubic kilometers over the 78-month period. Furthermore, they found that two thirds of this loss, or a total of 20 cubic kilometers for the study period, came from groundwater depletion in the Central Valley. Quantifying groundwater depletion can be challenging in many areas because of a lack of monitoring infrastructure and reporting requirements; the study shows that satellite-based monitoring can be a useful way to track groundwater volumes. The authors warn that the current rate of groundwater depletion in the Central Valley may be unsustainable and could have “potentially dire consequences for the economic and food security of the United States.” (Geophysical Research Letters, doi:10.1029/2010GL046442, 2011)

  16. Targeting Conservation Activities: Cost-effective Wetlands Restoration in the Central Valley of California

    OpenAIRE

    Newbold, Stephen C.

    2002-01-01

    This dissertation is about the public benefits that wetlands can provide and how those benefits depend on where wetlands are located in the landscape. The two broad objectives of the research were (1) to further our understanding of the role that landscape configuration plays in the provision of ecosystem services from wetlands, and (2) to enhance our practical ability to account for spatial effects and tradeoffs between competing environmental goals when evaluating, designing, and implement...

  17. Texture and depositional history of near-surface alluvial deposits in the central part of the western San Joaquin Valley, California

    Science.gov (United States)

    Laudon, Julie; Belitz, Kenneth

    1989-01-01

    Saline conditions and associated high levels of selenium and other soluble trace elements in soil, shallow ground water, and agricultural drain water of the western San Joaquin Valley, California, have prompted a study of the texture of near-surface alluvial deposits in the central part of the western valley. Texture is characterized by the percentage of coarse-grained sediment present within a specified subsurface depth interval and is used as a basis for mapping the upper 50 feet of deposits. Resulting quantitative descriptions of the deposits are used to interpret the late Quaternary history of the area. Three hydrogeologic units--Coast Range alluvium, flood-basin deposits, and Sierran sand--can be recognized in the upper 50 feet of deposits in the central part of the western San Joaquin Valley. The upper 30 feet of Coast Range alluvium and the adjacent 5 to 35 feet of flood-basin deposits are predominantly fine grained. These fine-grained Coast Range deposits are underlain by coarse-grained channel deposits. The fine-grained flood basin deposits are underlain by coarse-grained Sierran sand. The extent and orientation of channel deposits below 20 feet in the Coast Range alluvium indicate that streams draining the Coast Range may have been tributary to the axial stream that deposited the Sierran sand and that streamflow may have been to the southeast. The fining-upward stratigraphic sequence in the upper 50 feet of deposits and the headward retreat of tributary stream channels from the valley trough with time support a recent hypothesis of climatic control of alluviation in the western San Joaquin Valley.

  18. Vernal Pool Distribution - Central Valley, 2005 [ds650

    Data.gov (United States)

    California Department of Resources — "Great Valley Vernal Pool Distribution", originally mapped by Bob Holland, 2005. This dataset contains vernal pool areas mapped over Califorina's Central Valley,...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-11-01

    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.

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

    Science.gov (United States)

    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

  3. 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

    Science.gov (United States)

    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. 

  4. Climate Extremes and Adaptive Flood Management in the Central Valley, California

    Science.gov (United States)

    Munevar, A.; Das, T.

    2014-12-01

    Current evaluations of Central Valley, California flood control improvements are based on climate and hydrologic conditions that occurred over the past 100 years. This historical period includes significant flood events caused by intense precipitation, rapid snowmelt, and watershed conditions that, in combination, result in the hydrologic conditions that have shaped the current flood infrastructure and management. Future climate projections indicate the potential for increased flood peak flows and flood volumes in the Central Valley that will likely exceed the current capacity of existing flood control systems. Preliminary estimates of potential changes in flood flows have been developed for all the major watersheds in the Central Valley through the use of regionally downscaled climate projections and hydrologic modeling. Results suggest increasing flood risks that are dependent on spatial climate change patterns, individual watershed characteristics, and existing infrastructure investments. In many areas, the increasing flood risks cannot be managed through traditional flood infrastructure alone, and more adaptive measures are needed to improve resilience under climate extremes. Planning approaches are being applied to consider the full range of flood risks, and include tiered interventions for events beyond the floods-of-record. The on-going flood risk planning efforts demonstrate new, and sensible approaches toward improving resilience for uncertain and evolving climate extremes.

  5. Steelhead Critical Habitat, Central Valley - NOAA [ds123

    Data.gov (United States)

    California Department of Resources — This layer depicts areas designated for Steelhead Critical Habitat as well as habitat type and quality in the California Central Valley Evolutionary Significant...

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

    Science.gov (United States)

    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.

  7. 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

    Science.gov (United States)

    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 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-San Joaquin River Delta in the Central Valley. Through analysis of these field measurements, this dissertation presents the apportionment of observed CH4 and N2O

  8. Airborne Measurements of Ammonia and Implications for Ammonium Nitrate Formation in the Central Valley and the South Coast Air Basin of California

    Science.gov (United States)

    Nowak, J. B.; Neuman, J.; Bahreini, R.; Middlebrook, A. M.; Brock, C. A.; Frost, G. J.; Holloway, J. S.; McKeen, S. A.; Peischl, J.; Pollack, I. B.; Roberts, J. M.; Ryerson, T. B.; Trainer, M.; Parrish, D. D.

    2010-12-01

    Ammonia (NH3) is the dominant gas-phase base in the troposphere. As a consequence, NH3 abundance influences aerosol formation and composition. Ammonium nitrate aerosol is formed from the reaction of gas phase NH3 and nitric acid (HNO3). Anthropogenic emissions of NH3 and NOx (NO + NO2), which in sunlight can be oxidized to form HNO3, can react to form ammonium nitrate aerosol. Agricultural activity (i.e., dairy farms), and urban centers (i.e., Fresno, Los Angeles) are sources of ammonium nitrate gas-phase precursors in both the Central Valley and the South Coast Air Basin. Airborne measurements of NH3, HNO3, particle composition, and particle size distribution were made aboard the NOAA WP-3D research aircraft during May and June 2010 in the Central Valley and the South Coast Air Basin of California, as part of CalNex 2010 (California Research at the Nexus of Air Quality and Climate Change). The highest mixing ratios of NH3, well over 100 parts-per-billion by volume (ppbv), were measured downwind of dairy farms. The high NH3 mixing ratios were highly anti-correlated with HNO3 mixing ratios on fast time scales (~1 s) that correspond to short flight distances (~100 m). During these periods particulate nitrate (NO3-) concentrations increased, indicating ammonium nitrate formation. The meteorological and chemical environments during these periods will be studied to determine the factors driving or limiting ammonium nitrate formation and the resulting regional differences. Finally, the relationship between the NH3 observations and NH3 sources will be examined to assess the emissions and their contribution to ammonium nitrate abundance.

  9. U.S. Geological Survey Stream Gages located in the Central Valley, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the locations of, and links to USGS gages on the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central...

  10. The State of the Great Central Valley of California-Assessing the Region via Indicators: Public Health and Access to Care

    OpenAIRE

    Porter,, F.C.; Fox, MR; Beard,, Renee L. BA; Chapman, MR

    2005-01-01

    Each year the Great Valley Center produces a report in the five part State of the Great Central Valley series. The data is updated in 5-year increments. Based on the data, the Great Valley Center recognizes the potential to improve health outcomes throughout the region. Overall, the indicators suggest five strategies: * Invest in Prevention * Be Strategic With Limited Resources * Model Healthy Lifestyles for Youth * Build Coalitions in Support of a Healthier Environment * Re...

  11. Sin Sacrificio No Hay Recompensa: Apoyo as (Im)migrant Parental Engagement in Farmworking Families of the California Central Valley

    OpenAIRE

    Nava, Pedro Enrique

    2012-01-01

    This dissertation seeks to document how the life histories of Mexican origin (im)migrant farmworking families in a small rural California community shape their educational engagement experiences. Farmworkers living in communities like Trabajo are responsible for most of the agricultural production in California, yet their children attend under resourced schools that provide limited opportunities for academic success. This investigation examines how the intersection of their immigration statu...

  12. Spatially distributed pesticide exposure assessment in the Central Valley, California, USA

    International Nuclear Information System (INIS)

    Field runoff is an important transport mechanism by which pesticides move into the hydrologic environment of intensive agricultural regions such as California's Central Valley. This study presents a spatially explicit modeling approach to extend Pesticide Root Zone Model (PRZM), a field-scale pesticide transport model, into basin level. The approach was applied to simulate chlorpyrifos use in the Central Valley during 2003-2007. The average value of loading as percent of use (LAPU) is 0.031%. 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 implementations of best management practice (BMP) and total maximum daily load (TMDL). - Runoff generation and application timing are governing factors on spatiotemporal variability of pesticide sources.

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

    Science.gov (United States)

    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 100 years old), thickness of the vadose zone (from 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 with groundwater can complicate the use of tritium alone for age dating. The presence of radiogenic helium-4 in several samples with measurable tritium provides evidence of mixing between pre-modern and younger groundwater. Groundwater age-depth relationships are complicated, consistent with transient flow patterns in shallow agricultural groundwaters affected by irrigation pumping and recharge. For the multi-level installations in the southern dairies, both depth profiles and re-sampling after significant changes in groundwater elevation emphasize the need to sample

  14. Dissolved phosphorus distribution in shallow groundwater beneath dairy farms, Central Valley, California

    Science.gov (United States)

    Young, M. B.; Lockhart, K.; Holstege, D.; Applegate, O.; Harter, T.

    2012-12-01

    Concentrated animal farming operations (CAFOs) often produce surface runoff with high phosphorus (P) concentrations, but much less is known about P leaching and distributions in shallow groundwater beneath CAFOs. In this study, concentrations of soluble P were measured in shallow groundwater beneath ten dairies located in the Central Valley, California between 1998 and 2009 to assess spatial and temporal variability in areas of higher and lower hydrogeological vulnerability to groundwater contamination, and to investigate both land uses and physiochemical parameters associated with soluble P distribution. Distribution of bioavailable soil phosphate (bicarbonate extraction) was also examined in soil cores from several of the dairies in order to asses potential links between P distribution in the vadose zone and dissolved P concentrations near the top of the groundwater table. Dissolved P and other geochemical constituents were measured in 200 domestic drinking water wells to examine differences in shallow and deeper groundwater within the region. Samples from dairies and domestic wells were collected from two distinct regions in the Central Valley. The northern region (northeastern San Joaquin Valley) is characterized by a shallower water table, sandy soils, and groundwater discharges to surface water, whereas the southern region (Tulare Lake Basin) is characterized by a much deeper water table and does not have natural discharges of groundwater to surface water. Mean dissolved P concentrations were highest in the two dairies with the shallowest water table and sandiest soils, although dissolved P concentrations were highly variable across monitoring wells within individual dairies. Dissolved P ranged from below detection (water wells but not in the shallow dairy monitoring wells, suggesting that low oxygen was a major control on dissolved P in the deeper groundwater.

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

    Science.gov (United States)

    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

  16. Parkinson's Disease and Residential Exposure to Maneb and Paraquat From Agricultural Applications in the Central Valley of California

    OpenAIRE

    Costello, Sadie; Cockburn, Myles; Bronstein, Jeff; Zhang, Xinbo; Ritz, Beate

    2009-01-01

    Evidence from animal and cell models suggests that pesticides cause a neurodegenerative process leading to Parkinson's disease (PD). Human data are insufficient to support this claim for any specific pesticide, largely because of challenges in exposure assessment. The authors developed and validated an exposure assessment tool based on geographic information systems that integrated information from California Pesticide Use Reports and land-use maps to estimate historical exposure to agricultu...

  17. space Radar Image of Long Valley, California

    Science.gov (United States)

    1994-01-01

    An area near Long Valley, California, was mapped by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavor on April 13, 1994, during the first flight of the radar instrument, and on October 4, 1994, during the second flight of the radar instrument. The orbital configurations of the two data sets were ideal for interferometric combination -- that is overlaying the data from one image onto a second image of the same area to create an elevation map and obtain estimates of topography. Once the topography is known, any radar-induced distortions can be removed and the radar data can be geometrically projected directly onto a standard map grid for use in a geographical information system. The 50 kilometer by 50 kilometer (31 miles by 31 miles) map shown here is entirely derived from SIR-C L-band radar (horizontally transmitted and received) results. The color shown in this image is produced from the interferometrically determined elevations, while the brightness is determined by the radar backscatter. The map is in Universal Transverse Mercator (UTM) coordinates. Elevation contour lines are shown every 50 meters (164 feet). Crowley Lake is the dark feature near the south edge of the map. The Adobe Valley in the north and the Long Valley in the south are separated by the Glass Mountain Ridge, which runs through the center of the image. The height accuracy of the interferometrically derived digital elevation model is estimated to be 20 meters (66 feet) in this image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global

  18. BVOC and tropospheric ozone fluxes from an orange orchard in the California Central Valley

    Science.gov (United States)

    Fares, S.; Gentner, D. R.; Park, J.; Weber, R.; Karlik, J. F.; Goldstein, A. H.

    2010-12-01

    Citrus plants, especially oranges, are widely cultivated in the Central Valley of California and in many other countries experiencing Mediterranean climates. In many of these areas, orchards are often exposed to high levels of tropospheric ozone (O3) due to their location in polluted airsheds. Citrus take up O3 through their stomata and emit biogenic volatile organic compounds (BVOC), which can contribute to non-stomatal O3 removal through fast gas-phase reactions with O3. The study was performed in a navel orange orchard in Exeter, California. The CO2 & water fluxes, together with O3 uptake and BVOC emissions were measured continuously using eddy covariance techniques. Vertical concentration gradients of these compounds were also measured at 4 heights from the orchard floor to above the canopy. We observed high levels (up to 40 ppb) of volatile organic compounds including methanol, isoprene, monoterpenes, sesquiterpenes, and some additional oxygenated BVOC. Methanol dominated BVOC emissions (up to 5 nmol m-2 s-1) followed by acetone. Monoterpenes fluxes were also recorded during the all vegetative period, with the highest emissions taking place during flowering periods. The orchard represented a sink for ozone, with uptake rates on the order of 10 nmol m-2 s-1 during the central hours of the day. BVOC fluxes were highly temperature dependent, while ozone fluxes were more dependent on the physiology of the orchard, consistent with dominant removal occurring through the stomatal opening. The current research is aimed at: 1. Quantifying the uptake of O3 by citrus and partitioning it into stomatal and non-stomatal processes; 2. Quantifying the BVOC emissions and their dependence on physical and ecophysiological parameters.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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).

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. Airborne Doppler measurements of the central California extended sea breeze

    Science.gov (United States)

    Carroll, J. J.

    1985-01-01

    One data acquisition flight was executed in the late summer of 1984. The flight paths were designed to obtain measurements of the extended sea breeze penetration into the central valley of California over several hours. Data from this flight are being processed at Marshall Space Flight Center prior to release for analysis.

  4. Climate Variability and Water-Regulation Effects on Surface Water and Groundwater Interactions in California's Central Valley

    Science.gov (United States)

    Munoz-Arriola, F.; Dettinger, M. D.; Hanson, R. T.; Faunt, C.; Cayan, D. R.

    2011-12-01

    California's Central Valley is one of the most important agricultural areas in the world and is highly dependent on the availability and management of surface water and groundwater. As such, it is a valuable large-scale system for investigating the interaction of climate variability and water-resource management on surface-water and groundwater interactions. In the Central Valley, multiple tools are available to allow scientists to understand these interactions. However, the full effect of human activities on the interactions occurring along the Aquifer-Soil-Plant-Atmosphere continuum remains uncertain. Two models were linked to investigate how non-regulated (natural conditions) and regulated (releases from dams) surface-water inflows from the surrounding contributing drainage areas to the alluvial plains of the Central Valley affects the valley's surface-water supply and groundwater pumpage under different climate conditions. The Variable Infiltration Capacity (VIC) macroscale (surface) hydrologic model was used to estimate the non-regulated streamflow. The U.S. Geological Survey's recently developed Central Valley Hydrologic Model (CVHM) was used to route both the regulated and non-regulated streamflow to the Central Valley and simulate the resulting hydrologic system. The CVHM was developed using MODFLOW's Farm Process (MF-FMP) in order to simulate agricultural water demand, surface-water deliveries, groundwater pumpage, and return flows in 21 water-balance subregions. As such, the CVHM simulates conjunctive use of water, providing a broad perspective on changes in the water systems of the Valley. Inflows from the contributing mountain watersheds are simulated in CVHM using the streamflow-routing package for the 1961-2003 time period. In order to analyze the affect of climate variability, dry and wet years were identified from below the 10th and above the 90th percentiles, respectively, in a multi-decadal time series (1961-2003) of surface-water inflows. The

  5. Dissolved Pesticide and Organic Carbon Concentrations Detected in Surface Waters, Northern Central Valley, California, 2001-2002

    Science.gov (United States)

    Orlando, James L.; Jacobson, Lisa A.; Kuivila, Kathryn M.

    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

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

    Science.gov (United States)

    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

  7. Likelihood of volcanic eruption at Long Valley, California, is reduced

    Science.gov (United States)

    Kelly, D.

    1984-01-01

    A relatively low level of earthquake activity as well as reduced rates of ground deformation over the past year have led U.S Geological Survey scientists to conclude that the likelihood of imminent volcanic activity at Long Valley, California, is reduced from that of mid-1982 through 1983.

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

    Science.gov (United States)

    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.

  9. Evidence for Groundwater Contamination Vulnerability in California?s Central Valley

    International Nuclear Information System (INIS)

    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)18O) 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

  10. Evidence for Groundwater Contamination Vulnerability in California?s Central Valley

    Energy Technology Data Exchange (ETDEWEB)

    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. Comparison of particle-tracking and lumped-parameter models for determining groundwater age distributions and nitrate in water-supply wells, Central Valley, California, USA

    Science.gov (United States)

    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

  12. Spatial variability of ammonia and methane dairy emissions in the Central Valley, California with open-path mobile measurements during NASA DISCOVER-AQ 2013

    Science.gov (United States)

    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. Over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici) in the California Central valley: A case study Supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici) del trigo en el Valle Central de California: Estudio de caso

    OpenAIRE

    Huib Tollenaar

    2012-01-01

    To study the over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici) in the California Central Valley (CCV), temperature records from various locations in the CCV during the period 1950-2009 were examined for the occurrence of lethal maximum temperatures for the uredinia and uredinio-mycelium of this fungus. The lethal upper threshold temperature for the uredinial stage of P.s. tritici, estimated to be 40.5 °C on the basis of data published elsewhere, and the sum, accumulated...

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

    Science.gov (United States)

    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. Implementation of warm-cloud processes in a source-oriented WRF/Chem model to study the effect of aerosol mixing state on fog formation in the Central Valley of California

    Science.gov (United States)

    Lee, Hsiang-He; Chen, Shu-Hua; Kleeman, Michael J.; Zhang, Hongliang; DeNero, Steven P.; Joe, David K.

    2016-07-01

    The source-oriented Weather Research and Forecasting chemistry model (SOWC) was modified to include warm cloud processes and was applied to investigate how aerosol mixing states influence fog formation and optical properties in the atmosphere. SOWC tracks a 6-D chemical variable (X, Z, Y, size bins, source types, species) through an explicit simulation of atmospheric chemistry and physics. A source-oriented cloud condensation nuclei module was implemented into the SOWC model to simulate warm clouds using the modified two-moment Purdue Lin microphysics scheme. The Goddard shortwave and long-wave radiation schemes were modified to interact with source-oriented aerosols and cloud droplets so that aerosol direct and indirect effects could be studied. The enhanced SOWC model was applied to study a fog event that occurred on 17 January 2011, in the Central Valley of California. Tule fog occurred because an atmospheric river effectively advected high moisture into the Central Valley and nighttime drainage flow brought cold air from mountains into the valley. The SOWC model produced reasonable liquid water path, spatial distribution and duration of fog events. The inclusion of aerosol-radiation interaction only slightly modified simulation results since cloud optical thickness dominated the radiation budget in fog events. The source-oriented mixture representation of particles reduced cloud droplet number relative to the internal mixture approach that artificially coats hydrophobic particles with hygroscopic components. The fraction of aerosols activating into cloud condensation nuclei (CCN) at a supersaturation of 0.5 % in the Central Valley decreased from 94 % in the internal mixture model to 80 % in the source-oriented model. This increased surface energy flux by 3-5 W m-2 and surface temperature by as much as 0.25 K in the daytime.

  16. Habitat suitability and conservation of the Giant Gartersnake (Thamnophis gigas) in the Sacramento Valley of California

    Science.gov (United States)

    Halstead, B.J.; Wylie, G.D.; Casazza, M.L.

    2010-01-01

    Resource managers often have little information regarding the habitat requirements and distribution of rare species. Factor analysis-based habitat suitability models describe the ecological niche of a species and identify locations where these conditions occur on the landscape using existing occurrence data. We used factor analyses to assess the suitability of habitats for Thamnophis gigas (Giant Gartersnake), a rare, threatened species endemic to the Central Valley of California, USA, and to map the locations of habitat suitable for T. gigas in the Sacramento Valley. Factor analyses indicated that the niche of T. gigas is composed of sites near rice agriculture with low stream densities. Sites with high canal densities and near wetlands also appeared suitable, but results for these variables were sensitive to potential sampling bias. In the Sacramento Valley, suitable habitats occur primarily in the central portion of the valley floor. Based upon the results of the factor analyses, recovery planning for T. gigas will require an on-the-ground assessment of the current distribution and abundance of T. gigas, maintaining the few remaining natural wetlands and the practice of rice agriculture in the Sacramento Valley, and studying the effects of agricultural practices and land use changes on populations of T. gigas. ?? 2010 by the American Society of Ichthyologists and Herpetologists.

  17. Chinook Critical Habitat, Central Valley - NOAA [ds125

    Data.gov (United States)

    California Department of Resources — This layer depicts areas designated for Chinook Critical Habitat as well as habitat type and quality in the Central Valley Spring-run Evolutionary Significant Unit...

  18. Space Radar Image of Long Valley, California -Interferometry/Topography

    Science.gov (United States)

    1994-01-01

    These four images of the Long Valley region of east-central California illustrate the steps required to produced three dimensional data and topographics maps from radar interferometry. All data displayed in these images were acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour during its two flights in April and October, 1994. The image in the upper left shows L-band (horizontally transmitted and received) SIR-C radar image data for an area 34 by 59 kilometers (21 by 37 miles). North is toward the upper right; the radar illumination is from the top of the image. The bright areas are hilly regions that contain exposed bedrock and pine forest. The darker gray areas are the relatively smooth, sparsely vegetated valley floors. The dark irregular patch near the lower left is Lake Crowley. The curving ridge that runs across the center of the image from top to bottom is the northeast rim of the Long Valley Caldera, a remnant crater from a massive volcanic eruption that occurred about 750,000 years ago. The image in the upper right is an interferogram of the same area, made by combining SIR-C L-band data from the April and October flights. The colors in this image represent the difference in the phase of the radar echoes obtained on the two flights. Variations in the phase difference are caused by elevation differences. Formation of continuous bands of phase differences, known as interferometric 'fringes', is only possible if the two observations were acquired from nearly the same position in space. For these April and October data takes, the shuttle tracks were less than 100 meters (328 feet) apart. The image in the lower left shows a topographic map derived from the interferometric data. The colors represent increments of elevation, as do the thin black contour lines, which are spaced at 50-meter (164-foot) elevation intervals. Heavy contour lines show 250-meter intervals (820-foot). Total relief in

  19. 1:250,000-scale geology of the Dry Valley Hydrographic Area, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of digital geologic data for the Dry Valley Hydrographic area, Nevada and California. It was compiled from individual 1:250,000-scale geologic...

  20. Nitrate Contamination of Deep Aquifers in the Salinas Valley, California

    Science.gov (United States)

    Moran, J. E.; Esser, B. K.; Hillegonds, D. J.; Holtz, M.; Roberts, S. K.; Singleton, M. J.; Visser, A.; Kulongoski, J. T.; Belitz, K.

    2011-12-01

    The Salinas Valley, known as 'the salad bowl of the world', has been an agricultural center for more than 100 years. Irrigated row crops such as lettuce and strawberries dominate both land use and water use. Groundwater is the exclusive supply for both irrigation and drinking water. Some irrigation wells and most public water supply wells in the Salinas Valley are constructed to draw water from deep portions of the aquifer system, where contamination by nitrate is less likely than in the shallow portions of the aquifer system. However, a number of wells with top perforations greater than 75 m deep, screened below confining or semi-confining units, have nitrate concentrations greater than the Maximum Contaminant Limit (MCL) of 45 mg/L as NO3-. This study uses nitrate concentrations from several hundred irrigation, drinking water, and monitoring wells (Monterey County Water Resources Agency, 1997), along with tritium-helium groundwater ages acquired at Lawrence Livermore National Laboratory through the State of California Groundwater Monitoring and Assessment (GAMA) program (reported in Kulongoski et al., 2007 and in Moran et al., in press), to identify nitrate 'hot spots' in the deep aquifer and to examine possible modes of nitrate transport to the deep aquifer. In addition, observed apparent groundwater ages are compared with the results of transport simulations that use particle tracking and a stochastic-geostatistical framework to incorporate aquifer heterogeneity to determine the distribution of travel times from the water table to each well (Fogg et al., 1999). The combined evidence from nitrate, tritium, tritiogenic 3He, and radiogenic 4He concentrations, reveals complex recharge and flow to the capture zone of the deep drinking water wells. Widespread groundwater pumping for irrigation accelerates vertical groundwater flow such that high nitrate groundwater reaches some deep drinking water wells. Deeper portions of the wells often draw in water that recharged

  1. 76 FR 30002 - Establishment of the Antelope Valley of the California High Desert Viticultural Area

    Science.gov (United States)

    2011-05-24

    ... Antelope Valley of the California High Desert viticultural area in the Federal Register (75 FR 53877) on... the consumer with adequate information as to the identity and quality of the product. The Alcohol and... a single geographic descriptor, according to the petitioner. The modifier ``California High...

  2. Monthly Diversions from the Surface-Water Network of the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly diversions from the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses...

  3. Space Radar Image of Long Valley, California - 3D view

    Science.gov (United States)

    1994-01-01

    This is a three-dimensional perspective view of Long Valley, California by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This view was constructed by overlaying a color composite SIR-C image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle and, which then, are compared to obtain elevation information. The data were acquired on April 13, 1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR radar instrument. The color composite radar image was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is off the image to the left. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory

  4. Space Radar Image of Long Valley, California in 3-D

    Science.gov (United States)

    1994-01-01

    This three-dimensional perspective view of Long Valley, California was created from data taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This image was constructed by overlaying a color composite SIR-C radar image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The interferometry data were acquired on April 13,1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR instrument. The color composite radar image was taken in October and was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is the large dark feature in the foreground. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are

  5. A conceptual model for site-level ecology of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley, California

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.; Hansen, Eric C.; Scherer, Rick D.; Patterson, Laura C.

    2015-01-01

    Giant gartersnakes (Thamnophis gigas) comprise a species of semi-aquatic snakes precinctive to marshes in the Central Valley of California (Hansen and Brode, 1980; Rossman and others, 1996). Because more than 90 percent of their historical wetland habitat has been converted to other uses (Frayer and others, 1989; Garone, 2007), giant gartersnakes have been listed as threatened by the State of California (California Department of Fish and Game Commission , 1971) and the United States (U.S. Fish and Wildlife Service, 1993). Giant gartersnakes currently occur in a highly modified landscape, with most extant populations occurring in the rice - growing regions of the Sacramento Valley, especially near areas that historically were tule marsh habitat (Halstead and others, 2010, 2014).

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

    Science.gov (United States)

    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.

  7. Pesticide residues in the soil of the Central Jordan Valley

    International Nuclear Information System (INIS)

    Soil samples were taken from three zones in the Central Jordan Valley to evaluate the range of contamination with pesticides. Several pesticides belonging to different groups, particularly chlorinated hydrocarbon insecticides such as the DDT family and cyclodienes, were detected. In zone I, most of the chlorinated hydrocarbon insecticides occurred in open fields cultivated with tomatoes at a depth of 30-60 cm, at 0-15 and 15-30 cm in zone II, and at 0-15 and 30-60 cm in zone III. When considering pesticide residues under plastic house conditions cultivated with tomatoes, most of the chlorinated hydrocarbon insecticide residues were detected at a depth of 0-15 and 15-30 cm in zone I, at 0-15, 15-30 and 30-60 cm in zone II, and at 0-15 and 15-30 cm in zone III of the Central Jordan Valley. (author). 13 refs, 3 tabs

  8. Atmospheric Inverse Estimates of Methane Emissions from Central California

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chuanfeng; Andrews, Arlyn E.; Bianco, Laura; Eluszkiewicz, Janusz; Hirsch, Adam; MacDonald, Clinton; Nehrkorn, Thomas; Fischer, Marc L.

    2008-11-21

    Methane mixing ratios measured at a tall-tower are compared to model predictions to estimate surface emissions of CH{sub 4} in Central California for October-December 2007 using an inverse technique. Predicted CH{sub 4} mixing ratios are calculated based on spatially resolved a priori CH{sub 4} emissions and simulated atmospheric trajectories. The atmospheric trajectories, along with surface footprints, are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. An uncertainty analysis is performed to provide quantitative uncertainties in estimated CH{sub 4} emissions. Three inverse model estimates of CH{sub 4} emissions are reported. First, linear regressions of modeled and measured CH{sub 4} mixing ratios obtain slopes of 0.73 {+-} 0.11 and 1.09 {+-} 0.14 using California specific and Edgar 3.2 emission maps respectively, suggesting that actual CH{sub 4} emissions were about 37 {+-} 21% higher than California specific inventory estimates. Second, a Bayesian 'source' analysis suggests that livestock emissions are 63 {+-} 22% higher than the a priori estimates. Third, a Bayesian 'region' analysis is carried out for CH{sub 4} emissions from 13 sub-regions, which shows that inventory CH{sub 4} emissions from the Central Valley are underestimated and uncertainties in CH{sub 4} emissions are reduced for sub-regions near the tower site, yielding best estimates of flux from those regions consistent with 'source' analysis results. The uncertainty reductions for regions near the tower indicate that a regional network of measurements will be necessary to provide accurate estimates of surface CH{sub 4} emissions for multiple regions.

  9. Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

    Science.gov (United States)

    Wylie, G.D.; Casazza, M.L.; Gregory, C.J.; Halstead, B.J.

    2010-01-01

    The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

  10. Description of Imperial Valley, California for the assessment of impacts of geothermal energy development

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D.; Ermak, D.

    1976-08-26

    Impending geothermal development in the Imperial Valley of California has raised concern over the possible impacts of such development. As an initial step in impact assessment of geothermal projects, relevant features of the valley's physical and human environments are described. Particular attention is placed on features that may either influence development or be affected by it. Major areas of consideration include the valley's physical resources (i.e., land, air, water, and biological resources), economic, fiscal, and social characteristics of Imperial County, and geothermal laws.

  11. Geothermal systems of the Mono Basin-Long Valley region, eastern California and western Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, C.T.; Flynn, T.; Chapman, R.H.; Trexler, D.T.; Chase, G.R.; Bacon, C.F.; Ghusn, G. Jr.

    1985-01-01

    The region that includes Mono Basin, Long Valley, the Bridgeport-Bodie Hills area, and Aurora, in eastern California and western Nevada was studied to determine the possible causes and interactions of the geothermal anomalies in the Mono Basin-Long Valley region as a whole. A special goal of the study was to locate possible shallow bodies of magma and to determine their influence on the hydrothermal systems in the region. (ACR)

  12. Geologic Map of the Death Valley Ground-water Model Area, Nevada and California

    International Nuclear Information System (INIS)

    The purpose of this map is to provide the surface expression of the geology in the Death Valley ground-water model area to be incorporated initially into a 3-D geologic framework model and eventually into a transient ground-water flow model by the U.S. Geological Survey (D'Agnese, 2000; D'Agnese and Faunt, 1999; Faunt and others, 1999; and O'Brien and others, 1999). This work has been conducted in collaboration with the U.S. Department of Energy in order to assess regional ground water flow near the Nevada Test Site (NTS) and the potential radioactive waste repository at Yucca Mountain. The map is centered on the NTS and its perimeter encircles the entire boundary of the numerical flow model area, covering a total area of 57,000 km2. The physiography, geology, and tectonics of the model area are extremely complex (Hunt and Mabey, 1966; Stewart, 1980; Jennings, 1994; Slate and others, 2000; Wright and others, 1999b). The northern and eastern part of the area includes typical Basin and Range topography consisting of north-trending block-faulted ranges and intervening valleys. The central part contains diverse ranges, plateaus, basins, and alluvial flats (for example, the NTS volcanic highlands and Amargosa Valley). The rugged ranges and deep basins of the Death Valley region in eastern California are characteristic of the topography of the southern and western parts of the map area. The map spans numerous tectonic subdivisions of the Great Basin. Deformation includes several generations of upper Paleozoic to Mesozoic thrust faulting that have been dismembered by extensive regional Tertiary to Quaternary normal and strike-slip faults. Much of this extensional and translational deformation is active today, with rates and amounts that vary from low to moderate in the central, eastern, and northern parts of the study area in southern Nevada, to very high in the southwestern and western parts in eastern California. For detailed discussion of the tectonic framework of the

  13. Hydrology of modern and late Holocene lakes, Death Valley, California

    International Nuclear Information System (INIS)

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi2, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area

  14. Hydrology of modern and late Holocene lakes, Death Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  15. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    OpenAIRE

    D. R. Gentner; Ford, T. B.; Guha, A.; Boulanger, K.; J. Brioude; Angevine, W. M.; de Gouw, J. A; C. Warneke; J. B. Gilman; Ryerson, T. B.; J. Peischl; S. Meinardi; D. R. Blake; Atlas, E.; W. A. Lonneman

    2013-01-01

    Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at th...

  16. Hydrologic controls on the sources and dynamics of dissolved organic matter in an agricultural catchment in the Central Valley, California (U.S.A.)

    Science.gov (United States)

    Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Pellerin, B. A.; Bergamaschi, B. A.

    2008-12-01

    The influence of agricultural practices on the dynamics of dissolved organic matter (DOM) cycling in river systems is poorly understood. We investigated molecular compositions of DOM at 14 sites in an agriculturally-impacted catchment (Willow Slough; 415 km2) under several different flow regimes over the course of two years in order to investigate the influence of sub-catchments on the biogeochemistry at the mouth of the catchment. The Willow Slough catchment area includes eastern foothills of the inner Coast Range to the alluvial plains and encompasses diverse land uses, including natural grasslands, orchards, viticulture and pasture, all draining toward the Sacramento River. Knowledge of the composition of DOM composition is crucial, as dissolved organic carbon (DOC) can form EPA-regulated carcinogenic compounds during the drinking water disinfection process and is therefore considered a drinking water constituent of concern. Willow Slough offers the opportunity to examine carbon source, cycling and transportation through multiple flowpaths and land uses that are common in Californian agricultural watersheds. As a constituent of DOM, lignin phenols provide information on the source, composition, quality and degradation state of DOM. Uniquely derived from vascular plants, lignin phenols can be used to distinguish between angiosperm and gymnosperm tissues and carbon-normalized yields can offer insight on the proportion of vascular plant-derived carbon versus in-situ production. Throughout the Willow Slough watershed, ratios of syringyl to vanillyl and cinnamyl to vanillyl lignin phenols show that the vascular plant component of DOM can be primarily attributed to non-woody angiosperm tissues. Lower lignin phenol concentrations and carbon-normalized yields were observed in the headwaters (0.1-0.6 mg/100mg OC and 2.6-33 μg/L) versus the mouth (0.7-2.0 mg/100mg OC and 25-72 μg/L), indicating that mid-catchment tributaries play important roles in determining the

  17. Planimetric and volumetric analysis of channel change in the post-hydraulic mining period (1906-2009) in the Central Valley, California

    Science.gov (United States)

    Ghoshal, Subhajit

    Advances in remote sensing technologies can facilitate acquisition of topographical and planimetric information in fluvial environments and can produce spatial data with high spatial and temporal resolutions. Measuring planimetric and volumetric change in fluvial sediment budgets and geomorphic change detection was used for long-term monitoring of a fluvial system. Channel and floodplain changes caused by hydraulic gold mining sediment in this system are a major example of anthropogenic impacts on a fluvial system. This study uses remote sensing change-detection techniques to examine spatial and temporal patterns of HMS redistribution at a centennial time scale, and to measure and evaluate the magnitude and processes of a major channel and floodplain metamorphosis. Five reach-scale sites along the lower Yuba River and two sites on the Feather River were chosen for detailed analysis of planimetric and volumetric changes over a period of ~100 years. Volumetric changes were measured using DEM differencing and soft-copy photogrammetry methods, and planimetric changes were recorded from rectified maps and aerial photographs. This study indicates significant changes in channel morphology and sediment storage over the last 100 years. Large deposits of historical sediment remaining in the bed, banks and terraces of the lower Yuba River were remobilized by floods. The volumetric analysis shows the results of dredging of ditches, deposition in natural levees, and net erosion of high-water channels from 1906 or 1909 to 1999. Over the last century, channels incised up to ~13 m into mining sediment deposits. Systematic uncertainty analysis reveals vertical errors are mostly dependent on the topographical slopes and maximum errors are concentrated on the steep channel banks and scarps. The planimetric analysis shows significant reworking of sediment occurred throughout the 72-year period from 1937 to 2009. Substantial amounts of HMS remobilization occurred during major flood

  18. THE COST-EFFECTIVENESS OF ALTERNATIVE EMISSION CONTROL POLICIES IN THE SAN JOAQUIN VALLEY OF CALIFORNIA

    OpenAIRE

    Kim, Hong Jin

    2000-01-01

    This study analyzes the ROG control costs of stationary sources in the San Joaquin Valley of California. The cost-effectiveness of market incentive approaches such as an uniform marketable permit system, localized marketable permit system and an ambient permit system as well as a traditional command-and-control approach are examined.

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

    Science.gov (United States)

    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.

  20. Geology of the Desert Hot Springs-Upper Coachella Valley Area, California (with a selected bibliography of the Coachella Valley, Salton Sea, and vicinity)

    Energy Technology Data Exchange (ETDEWEB)

    Proctor, Richard J.

    1968-01-01

    The Desert Hot Springs area is in the upper Coachella Valley at the junction of three natural geomorphic provinces of California--the Transverse Ranges, the Peninsular Ranges, and the Colorado Desert. The mapped area is about 100 miles east of Los Angeles and lies principally in north central Riverside County. The oldest rocks in the area are Precambrian(?) amphibolitic and migmatized paragneisses of the San Gorgonio igneous-metamorphic (Chuckwalla) complex. They are intruded by Cretaceous diorite porphyry, Cactus Granite, quartz monzonite, intrusive breccia, and basic plutonic rocks. Of probable late Paleozoic age are the metamorphic rocks of the San Jacinto Mountains which form spurs projecting into San Gorgonio Pass and Coachella Valley.

  1. A preliminary investigation of the variables affecting the distribution of giant gartersnakes (Thamnophis gigas) in the Sacramento Valley, California

    Science.gov (United States)

    Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

    2015-01-01

    Giant gartersnakes (Thamnophis gigas) comprise a species of rare, semi-aquatic snake precinctive to the Central Valley of California. Because of the loss of more than 90% of their natural habitat, giant gartersnakes are listed as Threatened by the United States and California endangered species acts. Little is known, however, about the distribution of giant gartersnakes in the Sacramento Valley, which is where most extant populations occur. We conducted detection-nondetection surveys for giant gartersnakes throughout the rice-growing regions of the Sacramento Valley, and used occupancy models to examine evidence for the effects of landscape-scale GIS-derived variables, local habitat and vegetation composition, and prey communities on patterns of giant gartersnake occurrence. Although our results are based on a relatively small sample of sites, we found that distance to historic marsh, relative fish count, and an interaction of distance to historic marsh with proportion of habitat composed of submerged vegetation were important variables for explaining occupancy of giant gartersnakes. In particular, giant gartersnakes were more likely to occur closer to historic marsh and where relatively fewer fish were captured in traps. At locations in or near historic marsh, giant gartersnakes were more likely to occur in areas with less submerged vegetation, but this relationship was reversed (and more uncertain) at sites distant from historic marsh. Additional research with a larger sample of sites would further elucidate the distribution of giant gartersnakes in the Sacramento Valley.

  2. Over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central valley: A case study Supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo en el Valle Central de California: Estudio de caso

    Directory of Open Access Journals (Sweden)

    Huib Tollenaar

    2012-12-01

    Full Text Available To study the over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central Valley (CCV, temperature records from various locations in the CCV during the period 1950-2009 were examined for the occurrence of lethal maximum temperatures for the uredinia and uredinio-mycelium of this fungus. The lethal upper threshold temperature for the uredinial stage of P.s. tritici, estimated to be 40.5 °C on the basis of data published elsewhere, and the sum, accumulated during ten consecutive days, of the respective lethal temperature quotients (ALTQio, accounting for the partial lethal effect of the daily ambient temperatures between 30 and 40.5 °C on the uredinial stage of P.s. tritici, were used as yardsticks for thermal lethality. The results indicate that, in these 60 yr, the uredinia and the uredinio-mycelium of P.s. tritici could not possibly have over-summered at any of the locations studied. The Sierra Nevada Mountains, together with the Tulelake Basin and the coastal zone of the Pacific Ocean are the only two areas in California with appropriate environmental conditions for the summer-survival of the uredinial stage of stripe rust. Therefore, it is presumed that the inoculum for the initial infections of P.s. tritici in wheat fields in the CCV during the following growing season originates in either one or both of these areas, although, a potential third source of inoculum for the initial infections of stripe rust in the CCV could also be involved. Namely, the possible presence of telia with viable teliospores of P.s. tritici in autumn on straw of the threshed wheat fields or on volunteer wheat plants in the CCV, in conjunction with the accidental concurrence of nearby stripe rust susceptible barberry (Berberis spp., could lead to the development of alternative, endogenous sources of inoculum in the CCV.Para estudiar la supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo

  3. Pleistocene vertebrates of Silicon Valley (Santa Clara County, California)

    OpenAIRE

    Maguire, Kaitlin Clare; Holroyd, Patricia A.

    2016-01-01

    Here we report on late Pleistocene fossil vertebrates from new and previously described localities in Santa Clara County, California. The three new localities and specimens include: a partial mammoth pelvis from UCMP V91128 (Lawrence Expressway E); a juvenile cranial specimen of Mammuthus columbi from UCMP V99597 (SCVWD “Lupe” Mammoth), now on display at the San Jose Children’s Discovery Center; and a relatively diverse assemblage of medium- to large-sized mammals, including a nearly complete...

  4. Topping cogeneration feasibility study for the Central Valley Cooperative, Inc. cotton gin in Hanford, California

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, F.E.

    1980-08-01

    To define baseline operation, a detail measurement program was conducted to determine the detail character of electrical and thermal energy consumption in the gin. Much of the air moving equipment was found to be operating at low efficiencies. A conservation plan was developed, and energy consumption and energy costs were forecast for the future. Fuel supply alternatives were examined as were several prime mover engine technologies. Environmental and regulatory constraints were examined, and all systems examined were subjected to an economic analysis. Key results are discussed.

  5. Location of diversions from the surface-water network of the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the name and location for the diversions from the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central...

  6. Geotechnical environmental aspects of geothermal power generation at Herber, Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    1976-10-01

    The feasibility of constructing a 25-50 MWe geothermal power plant using low salinity hydrothermal fluid as the energy source was assessed. Here, the geotechnical aspects of geothermal power generation and their relationship to environmental impacts in the Imperial Valley of California were investigated. Geology, geophysics, hydrogeology, seismicity and subsidence are discussed in terms of the availability of data, state-of-the-art analytical techniques, historical and technical background and interpretation of current data. Estimates of the impact of these geotechnical factors on the environment in the Imperial Valley, if geothermal development proceeds, are discussed.

  7. Location of 24 extensometers used to measure compaction in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset describes the location of 21 extensometers used for observations of subsidence in the Central Valley Hydrologic Model (CVHM). The Central...

  8. The mechanism of intrusion of the Inyo Dike, Long Valley Caldera, California

    Science.gov (United States)

    Reches, Zeev; Fink, Jonathan

    1988-01-01

    The dike geometry of the 11-km-long Inyo Dike at the margins of the Long Valley calderas in eastern California is explained here in terms of the interaction between tectonic stresses and local variations in host rock rheology. Relationships between tectonic and magmatic stresses are evaluated, and the magnitude of magmatic pressure at the depth necessary to get the dike to the surface is estimated. The application of the model to other volcanoes is also discussed.

  9. Overwintering Biology of Culex (Diptera: Culicidae) Mosquitoes in the Sacramento Valley of California

    OpenAIRE

    NELMS, BRITTANY M.; Macedo, Paula A.; KOTHERA, LINDA; Savage, Harry M.; REISEN, WILLIAM K.

    2013-01-01

    At temperate latitudes, Culex (Diptera: Culicidae) mosquitoes typically overwinter as adult females in reproductive arrest and also may serve as reservoir hosts for arboviruses when cold temperatures arrest viral replication. To evaluate their role in the persistence of West Nile virus (WNV) in the Sacramento Valley of California, the induction and termination of diapause were investigated for members of the Culex pipiens (L.) complex, Culex tarsalis Coquillett, and Culex stigmatosoma Dyar un...

  10. Comparison of Oxygenate Mixing Ratios Observed in the San Joaquin Valley, California, as a Consequence of Dairy Farming

    Science.gov (United States)

    Yang, M. M.; Blake, D. R.

    2009-12-01

    The San Joaquin Valley Air Basin in Central California is plagued with air quality problems, and is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). One of the main sources of Volatile Organic Compounds (VOCs), and indirect sources of ozone in the Valley, has been identified as dairy farming (2). Among these compounds, we have found that several OVOCs such as ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Since 2008, several different types of sampling protocols have been employed by our group in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates (2). In 2008 and 2009, samples were in early summer, allowing us to compare the difference in concentration levels between both years.The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, for both 2008 and 2009, as much as 15% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that the data observed in 2008 is consistent with that observed in 2009, with a slight decrease in concentrations overall for 2009. 1. Lindberg, J. Analysis of the San Joaquin Valley 2007 Ozone Plan. State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. M. Yang, S. Meinardi, C. Krauter, D.R. Blake. Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin

  11. Structural Evolution of the East Sierra Valley System (Owens Valley and Vicinity, California: A Geologic and Geophysical Synthesis

    Directory of Open Access Journals (Sweden)

    Richard J. Blakely

    2013-04-01

    Full Text Available The tectonically active East Sierra Valley System (ESVS, which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm, which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3–3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

  12. Seismic study of soil dynamics at Garner Valley, California

    International Nuclear Information System (INIS)

    The Garner Valley downhole array (GVDA) of force-balanced accelerometers was designed to determine the effect that near-surface soil layers have on surface ground motion by measuring in situ seismic waves at various depths. Although there are many laboratory, theoretical and numerical studies that are used to predict the effects that local site geology might have on seismic waves, there are very few direct measurements that can be used to confirm the predictions made by these methods. The effects of local site geology on seismic ground motions are critical for estimating the base motion of structures. The variations in site amplifications at particular periods can range over a factor of 20 or more in comparing amplitude spectra from rock and soil sites, e.g., Mexico City (1985) or San Francisco (1989). The basic phenomenon of nonlinear soil response, and by inference severe attenuation of seismic waves, has rarely been measured although it is commonly observed in laboratory experiments. The basic question is whether or not the local site geology amplifies are attenuates the seismic ground motion. Because the answer depends on the interaction between the local site geology and the amplitude as well as the frequency content of the incoming seismic waves, the in situ measurements must sample the depth variations of the local structure as well as record seismic waves over as wide a range as possible in amplitude and frequency

  13. Radon in groundwater of the Long Valley Caldera, California

    International Nuclear Information System (INIS)

    In the Long Valley caldera, an area of recently (∼550 y) active volcanism and current seismic activity, 222Rn concentrations in hot, warm, and cold spring waters have been measured since 1982. Rn contents of the waters correlate inversely with temperature and specific conductance, with high concentrations (1500 to 2500 pCi/l) occurring in dilute cold springs on the margins of the caldera, and low concentrations (12 to 25 pCi/l) in hot to boiling springs. Rn correlates only slightly with the uranium contents of the wide range of rocks which host the hydrological system feeding the springs. These environmental effects on the radon record may mask responses to small or distant seismic, volcanic, or crustal deformation events. To date, anomalous changes in water-borne Rn have been observed in connection with at least one earthquake, which occurred close to the monitoring site. This continuing study points out that an understanding of the geological setting, its associated hydrological system, and environmental influences is necessary to properly evaluate concentrations and changes in groundwater radioactivity

  14. Seismic study of soil dynamics at Garner Valley, California

    International Nuclear Information System (INIS)

    The Gamer Valley downhole array (GVDA) is a five element array of three-component, dual-gain force balance accelerometers that are capable of measuring accelerations from 3 x 10-6 g to 2.0 g over a frequency range from 0.0 Hz (0.025, high-gain) Hz to 100 Hz. Since being installed in July 1989 GVDA has recorded 164 earthquakes with magnitudes from 4.7 to 1.2 with epicentral distances from 0-110 km. The maximum recorded acceleration recorded is 89 cm/s2 from a ML 4.2 earthquake 16.6 km (hypocentral distance) from GVDA. The average amplification due to the local geology is about 13 for over five orders of magnitude in the size of the recorded earthquakes. The average spectral ratio of horizontal acceleration amplitude spectrum at the surface divided by the amplitude spectrum at 220 m shows a mean amplification around ten for the frequency range 2.0-30 Hz. Definite resonance peaks exist at about 1.7, 3.0 and 12.0 Hz where the spectral ratio is nearly 40. The average spectral ratio for depth range from 22 m to 220 m shows an overall mean level that is about a factor of three lower than that for 0 m to 220 m. However, the spectral ratio for 22/220 shows similar resonance peaks. Pronounced attenuation occurs for frequencies greater than 35 Hz

  15. Numerical understanding of regional scale water table behavior in the Guadalupe Valley aquifer, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    J. R. Campos-Gaytan

    2006-05-01

    Full Text Available A regional groundwater flow model was developed, in order to evaluate the water table behavior in the region of the Guadalupe Valley, in Baja California, Mexico. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semi-arid climate with low surface water availability; resulting in an extensive use of groundwater in local aquifer. Based on historic piezometric information of the last two decades, however, a negative evolution could be observed, resulting a negative storage volume. So far, there is not an integral hydrogeological evaluation that determine the real condition of the groundwater resource, and that permit to planning a management of the Guadalupe Valley Aquifer. A steady-state calibration model was carried out in order to obtain the best possible match to measured levels at the Guadalupe Valley Aquifer. The contours of calculated water table elevations for January 1983 were reproduced. Generally, the comparison of the observed and calculated water table configurations have a good qualitative and quantitatively adjustment. Nowadays, it is count with a hydrogeological model that can be used for simulates the groundwater flow in the region of the Guadalupe Valley.

  16. Radon in groundwater of the Long Valley Caldera, California

    International Nuclear Information System (INIS)

    In the Long Valley caldera, an area of recently (-- 550 y) active volcanism and current seismic activity, 222Rn concentrations in hot, warm, and cold spring waters have been measured since 1982. Rn contents of the waters correlate inversely with temperature and specific conductance, with high concentrations (1500 to 2500 rhoCi1) occurring in dilute cold springs on the margins of the caldera, and low concentrations (12 to 25 rhoCi1) in hot to boiling springs. Rn correlates only slightly with the uranium contents of the rocks which host the hydrological system feeding the springs, which encompass a wide range of rock types. Anomalous changes in groundwater Rn contents may accompany or precede earthquake activity, and a continuous Rn monitoring system was installed in 1983 to monitor short-term variations. A gamma detector is submerged in a natural pond fed by --110C spring waters with --700 rhoCi1 Rn, and measured gamma activity is due almost entirely to 222Rn in the water. The gamma record, which is integrated hourly, shows a consistent, pronounced diurnal variation (--30% of mean count rate), and weaker higher frequency variations. This pattern correlates well with small variations (0C) in water temperature at the Rn monitoring point, and is strongly influenced by precipitation and by patterns of water flow in the pond. It does not adhere closely to a tidal pattern. These environmental effects on the radon record may mask responses to small or distant seismic events. To date, anomalous changes in waterborne Rn have been observed in connection with at least one earthquake, which occurred close to the monitoring site. This continuing study points out that an understanding of the geological setting, its associated hydrological system, and environmental influences is necessary to properly evaluate concentrations and changes in groundwater radioactivity

  17. Technical Analysis of In-Valley Drainage Management Strategies for the Western San Joaquin Valley, California

    Science.gov (United States)

    Presser, Theresa S.; Schwarzbach, Steven E.

    2008-01-01

    The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed

  18. Extent of Corcoran Clay modified from Page (1986) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the areal extent of the Corcoran Clay Member of the Tulare Formation. The complex hydrologic system of the Central Valley is simulated...

  19. Locations of hydraulic-head observations (HOBS) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the well locations for hydraulic-head observations used in the calibration of the transient hydrologic model of the Central Valley flow...

  20. Spatial Provinces and Domains of the Central Valley for Textural Analysis

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the 9 major areas used to subdivide the Central Valley for the interpolation of the percentage of coarse-grained deposits into the...

  1. Location of General Head Boundaries (GHB) in the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset represents the area where lateral flow into and out of the Central Valley groundwater-flow system occurs. The General Head Boundary (GHB) is...

  2. Contaminant exposure and reproductive health of sandhill cranes in the Central Platte River Valley, Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The central Platte River Valley provides crucial staging habitat for the endangered whooping crane (Grus americana) and the mid-continent population of sandhill...

  3. Identification of environmental control technologies for geothermal development in the Imperial Valley of California

    Energy Technology Data Exchange (ETDEWEB)

    Snoeberger, D.F.; Hill, J.H.

    1978-10-05

    Control technologies to manage environmental impacts from geothermal developments in California's Imperial Valley from development to 1985 are discussed. Included are descriptions of methods for managing land subsidence by fluid injection; for preventing undesirable induced seismicity or mitigating the effects of seismic events; for managing liquid wastes through pretreatment or subsurface injection; for controlling H/sub 2/S by dispersal, reinjection, and chemical treatment of effluents; and for minimizing the impact of noise from power plants by setting up buffer zones and exclusion areas.

  4. 76 FR 57845 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley; Attainment Plan for...

    Science.gov (United States)

    2011-09-16

    ... exposure. See ``Fact Sheet, Proposal to Revise the National Ambient Air Quality Standards for Ozone... to measures and reductions by the SJV Air Pollution Control District and the California Air Resources... Valley Air Pollution Control District, 1990 E. Gettysburg, Fresno, California 93726. The SIP...

  5. Quaternary tectonics and basin history of Pahrump and Stewart Valleys, Nevada and California

    International Nuclear Information System (INIS)

    The Pahrump fault system is an active fault system located in Pahrump and Stewart Valleys, Nevada and California, in the southern part of the Basin and Range Province. This system is 50 km long by 30 km wide and is comprised of three fault zones: the right-lateral East Nopah fault zone, the right-oblique Pahrump Valley fault zone, and the normal West Spring Mountains fault zone. All three zones have geomorphic evidence for late Quaternary activity. Analysis of active fault patterns and seismic reflection lines suggests that the Pahrump basin has had a two-stage genesis, an early history associated with a period of low angle detachment faulting probably active 10-15 Ma, and a more recent history related to the present dextral shear system, probably active post-4 Ma

  6. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    Science.gov (United States)

    Gentner, D. R.; Ford, T. B.; Guha, A.; Boulanger, K.; Brioude, J.; Angevine, W. M.; de Gouw, J. A.; Warneke, C.; Gilman, J. B.; Ryerson, T. B.; Peischl, J.; Meinardi, S.; Blake, D. R.; Atlas, E.; Lonneman, W. A.; Kleindienst, T. E.; Beaver, M. R.; St. Clair, J. M.; Wennberg, P. O.; VandenBoer, T. C.; Markovic, M. Z.; Murphy, J. G.; Harley, R. A.; Goldstein, A. H.

    2014-05-01

    Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions, and provide average source profiles. To examine the spatial distribution of emissions in the San Joaquin Valley, we developed a statistical modeling method using ground-based data and the FLEXPART-WRF transport and meteorological model. We present evidence for large sources of paraffinic hydrocarbons from petroleum operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes, most of which have limited previous in situ measurements or characterization in petroleum operation emissions. Observed dairy emissions were dominated by ethanol, methanol, acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The petroleum operations source profile was developed using the composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil. The observed source profile is

  7. California GAMA Program: Groundwater Ambient Monitoring and Assessment Results for the Sacramento Valley and Volcanic Provinces of Northern California

    Energy Technology Data Exchange (ETDEWEB)

    Moran, J E; Hudson, G B; Eaton, G F; Leif, R

    2005-01-20

    In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as methyl tert butyl ether (MTBE) from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater monitoring plan, and led to the initiation of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The primary objective of the California Aquifer Susceptibility (CAS) project (under the GAMA Program) is to assess water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey, the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement this groundwater assessment program. In 2003, LLNL carried out this vulnerability study in the Sacramento Valley and Volcanic Provinces. The goal of the study is to provide a probabilistic assessment of the relative vulnerability of groundwater used for the public water supply to contamination from surface sources. This assessment of relative contamination vulnerability is made based on the results of two types of analyses that are not routinely carried out at public water supply wells: ultra low-level measurement of volatile organic compounds (VOCs), and groundwater age dating (using the tritium-helium-3 method). In addition, stable oxygen isotope measurements

  8. Fog and Haze in California's San Joaquin Valley

    Science.gov (United States)

    2001-01-01

    This illustration features images of southern California and southwestern Nevada acquired on January 3, 2001 (Terra orbit 5569), and includes data from three of MISR's nine cameras. The San Joaquin Valley, which comprises the southern extent of California's Central Valley, covers much of the viewed area. Also visible are several of the Channel Islands near the bottom, and Mono and Walker Lakes, which stand out as darker patches near the top center, especially in the vertical and backward oblique images. Near the lower right of each image is the Los Angeles Basin, with the distinctive chevron shape of the Mojave Desert to its north.The Central Valley is a well-irrigated and richly productive agricultural area situated between the Coast Range and the snow-capped Sierra Nevadas. During the winter, the region is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected sunlight, dramatic differences in the MISR images are apparent as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, the pervasive haze that fills most of the valley is only slightly visible in the vertical view. At the oblique angles, the haze is highly distinguishable against the land surface background, particularly in the forward-viewing direction. Just above image center, the forward view also reveals bluish-tinged plumes near Lava Butte in Sequoia National Forest, where the National Interagency Coordination Center reported an active forest fire.The changing surface visibility in the multi-angle data allows us to derive the amount of atmospheric haze. In the lower right quadrant is a map of haze amount determined from automated processing of the MISR imagery. Low amounts of haze are shown in blue, and a variation in hue through shades of green, yellow, and red indicates progressively larger amounts of airborne particulates. Due to the topographically

  9. Stodder: Mechanisms and Trends in the Decline of the Costanoan Indian Population of Central California

    OpenAIRE

    Milliken, Randall

    1987-01-01

    Mechanisms and Trends in the Decline of the Costanoan Indian population of Central California Ann Lucy Wiener Stodder. Salinas: Coyote Press Archives of California Prehistory No. 4, 1986, vi+ 78 pp., 5 figures, 11 tables, bibliography, $4.95 (paper).

  10. Assessment of the importance of alfalfa to the epidemiology of xylellae diseases in the San Joaquin Valley of California

    Science.gov (United States)

    The role of alfalfa in the epidemiology of xylellae diseases in the San Joaquin Valley of California was assessed. Alfalfa was investigated as it is a known host of Xylella fastidiosa and often harbors large populations of a native vector, Draeculacephala minerva. Laboratory inoculation of fourtee...

  11. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    Directory of Open Access Journals (Sweden)

    D. R. Gentner

    2013-10-01

    Full Text Available Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. Ground site measurements in Bakersfield and aircraft measurements of reactive gas-phase organic compounds were made in this region as part of the CalNex (California Research at the Nexus of Air Quality and Climate Change project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions from these prominent sources that are relatively understudied compared to motor vehicles We also developed a statistical modeling method with the FLEXPART-WRF transport and meteorological model using ground-based data to assess the spatial distribution of emissions in the San Joaquin Valley. We present evidence for large sources of paraffinic hydrocarbons from petroleum extraction/processing operations and oxygenated compounds from dairy (and other cattle operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes that have limited previous in situ measurements or characterization in emissions from petroleum operations. Observed dairy emissions were dominated by ethanol, methanol, and acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well-correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The good agreement of the observed petroleum operations source profile with the measured composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil suggests a fugitive emissions pathway during petroleum extraction, storage, or processing with

  12. Irrigation runoff insecticide pollution of rivers in the Imperial Valley, California (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Vlaming, V. de [Aquatic Toxicology Laboratory, VM: APC, 1321 Haring Hall, University of California, Davis, CA 95616 (United States)]. E-mail: vldevlaming@ucdavis.edu; DiGiorgio, C. [Department of Water Resources, P.O. Box 942836, Sacramento, CA 94236 (United States); Fong, S. [Aquatic Toxicology Laboratory, VM: APC, 1321 Haring Hall, University of California, Davis, CA 95616 (United States); Deanovic, L.A. [Aquatic Toxicology Laboratory, VM: APC, 1321 Haring Hall, University of California, Davis, CA 95616 (United States); Paz Carpio-Obeso, M. de la [Colorado River Basin Region Water Quality Control Board, 73-720 Fred Waring Drive, Suite 100, Palm Desert, CA 92260 (United States); Miller, J.L. [AQUA-Science, 17 Arboretum Drive, Davis, CA 95616 (United States); Miller, M.J. [AQUA-Science, 17 Arboretum Drive, Davis, CA 95616 (United States); Richard, N.J. [Division of Water Quality, State Water Resources Control Board, 1001 I Street, Sacramento, CA 95814 (United States)

    2004-11-01

    The Alamo and New Rivers located in the Imperial Valley, California receive large volumes of irrigation runoff and discharge into the ecologically sensitive Salton Sea. Between 1993 and 2002 we conducted a series of studies to assess water quality using three aquatic species: a cladoceran (Ceriodaphnia dubia), a mysid (Neomysis mercedis), and a larval fish (Pimephales promelas). Although no mortality was observed with the P. promelas, high-level toxicity to the invertebrate species was documented in samples from both rivers during many months of each year. Toxicity identifications and chemical analyses identified the organophosphorus insecticides (OP), chlorpyrifos and diazinon, as the cause of C. dubia toxicity. The extent of the C. dubia mortality was highly correlated with quantities of these OPs applied in the river watersheds. C. dubia mortality occurred during more months of our 2001/2002 study than in the 1990s investigations. During 2001/2002, the extensive C. dubia mortality observed in New River samples was caused by OP insecticide pollution that originated from Mexico. Mortality to N. mercedis in New River samples was likely caused by contaminants other than OP insecticides. Our studies document OP insecticide-caused pollution of the Alamo River over a 10-year period and provide the necessary information for remediation efforts. - Capsule: Organophosphorous insecticides in runoff water from the USA and Mexico have impacted rivers in the Imperial Valley, California.

  13. Irrigation runoff insecticide pollution of rivers in the Imperial Valley, California (USA)

    International Nuclear Information System (INIS)

    The Alamo and New Rivers located in the Imperial Valley, California receive large volumes of irrigation runoff and discharge into the ecologically sensitive Salton Sea. Between 1993 and 2002 we conducted a series of studies to assess water quality using three aquatic species: a cladoceran (Ceriodaphnia dubia), a mysid (Neomysis mercedis), and a larval fish (Pimephales promelas). Although no mortality was observed with the P. promelas, high-level toxicity to the invertebrate species was documented in samples from both rivers during many months of each year. Toxicity identifications and chemical analyses identified the organophosphorus insecticides (OP), chlorpyrifos and diazinon, as the cause of C. dubia toxicity. The extent of the C. dubia mortality was highly correlated with quantities of these OPs applied in the river watersheds. C. dubia mortality occurred during more months of our 2001/2002 study than in the 1990s investigations. During 2001/2002, the extensive C. dubia mortality observed in New River samples was caused by OP insecticide pollution that originated from Mexico. Mortality to N. mercedis in New River samples was likely caused by contaminants other than OP insecticides. Our studies document OP insecticide-caused pollution of the Alamo River over a 10-year period and provide the necessary information for remediation efforts. - Capsule: Organophosphorous insecticides in runoff water from the USA and Mexico have impacted rivers in the Imperial Valley, California

  14. San Fernando Valley California Earthquakes of 1971 and 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This slide set compares two earthquakes that were separated by a distance of 10 miles and a time of 23 years. Disproving the notion that once an earthquake has...

  15. Patterns of vegetation in the Owens Valley, California

    Science.gov (United States)

    Ustin, S. L.; Rock, B. N.; Woodward, R. A.

    1986-01-01

    Spectral characteristics of semi-arid shrub communities were examined using Airborne Imaging Spectrometer (AIS) data collected in the tree mode on 23 May 1985. Mesic sites with relatively high vegetation density and distinct zonation patterns exhibited greater spectral signature variations than sites with more xeric shrub communities. Spectral signature patterns were not directly related to vegetation density or physiognomy, although spatial maps derived from an 8-channel maximum likelihood classification were supported by photo-interpreted surface features. In AIS data, the principal detected effect of shrub vegetation on the alluvial fans is to lower reflectance across the spectrum. These results are similar to those reported during a period of minimal physiological activity in autumn, indicating that shadows cast by vegetation canopies are an important element of soil-vegetation interaction under conditions of relatively low canopy cover.

  16. A Resilience-Based Approach to the Conservation of Valley Oak in a Southern California Landscape

    Directory of Open Access Journals (Sweden)

    James J. Hayes

    2014-07-01

    Full Text Available Conservation thinking will benefit from the incorporation of a resilience perspective of landscapes as social-ecological systems that are continually changing due to both internal dynamics and in response to external factors such as a changing climate. The examination of two valley oak stands in Southern California provides an example of the necessity of this systems perspective where each stand is responding differently as a result of interactions with other parts of the landscape. One stand is experiencing regeneration failure similar to other stands across the state, and is exhibiting shifts in spatial pattern as a response to changing conditions. A nearby stand is regenerating well and maintaining spatial and structural patterns, likely due to the availability of imported water associated with upstream urban development. Valley oak stands have a capacity for reorganization as a response to changes in the landscape and environmental conditions. This reorganization can benefit conservation efforts; however, we must ask what limits there are to valley oak’s capacity to reorganize and still maintain its ecological function in face of increasing changes in climate and land cover. The usefulness of resilience as a concept in conservation is discussed at several scales from the stand to the landscape.

  17. Aeromagnetic map of the Death Valley ground-water model area, Nevada and California; TOPICAL

    International Nuclear Information System (INIS)

    This aeromagnetic map of the Death Valley ground-water model area was prepared from numerous separate aeromagnetic surveys that were gridded, merged, and described by Hildenbrand and Kucks (1988) and by McCafferty and Grauch (1997). These data are available in grid format from the EROS Data Center, U.S. Geological Survey, Sioux Falls, South Dakota, 57198, and from the National Geophysical Data Center, 325 Broadway, E/GC4, Boulder, Colo., 80303. Magnetic investigations of the Death Valley ground-water basin are part of an interagency effort by the U.S. Geological Survey (USGS) and the U.S. Department of Energy (Interagency Agreement DE-AI08-96NV11967) to help characterize the geology and hydrology of southwest Nevada and adjacent parts of California (Blakely and others, 2000b). The Death Valley ground-water model is located between lat 35 degrees 00' and 38 degrees 15' N., and long 115 degrees and 118 degrees W

  18. A hydrogeologic map of the Death Valley region, Nevada, and California, developed using GIS techniques

    International Nuclear Information System (INIS)

    In support of Yucca Mountain site characterization studies, a hydrogeologic framework was developed, and a hydrogeologic map was constructed for the Death Valley region. The region, covering approximately 100,000 km2 along the Nevada-California border near Las Vegas, is characterized by isolated mountain ranges juxtaposed against broad, alluvium-filled valleys. Geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. The regional ground-water flow system can best be described as a series of connected intermontane basins in which ground-water flow occurs in basin-fill deposits, carbonate rocks, clastic rocks, and volcanic rocks. Previous investigations have developed more site-specific hydrogeologic relationships; however, few have described all the lithologies within the Death Valley regional ground-water flow system. Information required to characterize the hydrogeologic units in the region was obtained from regional geologic maps and reports. Map data were digitized from regional geologic maps and combined into a composite map using a geographic information system. This map was simplified to show 10 laterally extensive hydrogeologic units with distinct hydrologic properties. The hydraulic conductivity values for the hydrogeologic units range over 15 orders of magnitude due to the variability in burial depth and degree of fracturing

  19. Measured compaction for 24 extensometers in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the compaction data for 24 extensometers used for observations in the Central Valley Hydrologic Model (CVHM). The Central Valley...

  20. Evapotranspiration Input Data for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains monthly reference evapotranspiration (ETo) data for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  1. Late Cenozoic N-S shortening across the central Garlock fault in Pilot Knob Valley, California - Implications for structural and kinematic relations with the Panamint Valley fault system

    Science.gov (United States)

    Rittase, W. M.; Walker, J. D.; Kirby, E.; McDonald, E.; Gosse, J.; Spencer, J. Q.; Mojave Red Iwbc

    2010-12-01

    The intersection of the dextral (2-3 mm/yr) Panamint Valley fault system (PVFS) with the sinistral (5-15 mm/yr) Garlock fault (GF) in eastern Pilot Knob Valley (PKV) controls the active off-fault tectonic deformation in the southern Slate Range (SSR) and northern PKV. We suggest here that the 430+ m uplift of late Cenozoic sediments adjacent to the SSR partially accommodates decreased slip on the southern PVFS near the GF. We present preliminary data that constrain modern uplift in northern PKV: (1) Be-10 cosmogenic profiles, (2) OSL samples, (3) existing Earthscope 0.5 m airborne LiDAR and newly acquired terrestrial LiDAR, and (4) detailed soil PDI’s. Two uplifted terrace treads adjacent to the GF and one adjacent to the SSF are analyzed herein. A 50 ± 13 ka Be-10 cosmogenic profile age for a 16-m-high terrace tread adjacent to the GF suggests an uplift rate of ~0.32 ± 0.08 mm/yr. An additional Be-10 cosmogenic profile from a 12.5-m-high tread located 4.5 km west on the GF will test for spatial and temporal uplift rate variability. An OSL sample collected from this second cosmogenic profile will check the terrace’s age estimation. A second OSL sample collected from a 25.5-m-high terrace will allow for a slip-rate determination of a reverse fault near the SSR. We attribute the localized uplift between the SSR and the GF in northern PKV as strain accommodation between the southern PVFS and GF. If all reverse faults responsible for 430+ m of uplift are assumed to dip 70-80°, then approximately 155-76 m of horizontal N-S shortening is tenable. Likewise, the ca. 50 ka uplifted terrace adjacent to the GF would indicate a 0.12-0.06 mm/yr component of N-S shortening. Additional reverse faults to the north will add to this value, but lack of surfaces suitable for dating make a regional shortening estimate over this time interval challenging.

  2. Inflation of Long Valley caldera, California, Basin and Range strain, and possible Mono Craters dike opening from 1990-94 GPS surveys

    Science.gov (United States)

    Marshall, G.A.; Langbein, J.; Stein, R.S.; Lisowski, M.; Svarc, J.

    1997-01-01

    Five years of annual Global Positioning System (GPS) surveys of a network centered on Long Valley, California, constrain displacement rates for these stations relative to a central station in the network. These observations are consistent with recent models of resurgent dome inflation in Long Valley (Langbein et al., 1995) and have sufficient signal to detect the presence of Basin and Range strain in the Long Valley region. The data also allow for the possibility of dike inflation beneath the Mono Craters; dike intrusion is consistent with the Mono Craters' recent geologic history of ash eruptions, with seismic tomography, leveling data, and geologic studies of these volcanic domes and flows. Copyright 1997 by the American Geophysical Union.

  3. Late Cenozoic geology and lacustrine history of Searles Valley, Inyo and San Bernardino Counties, California

    Science.gov (United States)

    Nathenson, M.; Smith, G. I.; Robinson, J. E.; Stauffer, P. H.; Zigler, J. L.

    2010-12-01

    George Smith’s career-long study of the surface geology of the Searles Valley was recently published by the USGS (Smith, 2009, online and printed). The co-authors of this abstract are the team responsible for completing the publication from the original materials. Searles Valley is an arid, closed basin lying 70 km east of the south end of the Sierra Nevada, California. During those parts of late Pliocene and Pleistocene time when precipitation and runoff from the east side of the Sierra Nevada into the Owens River were much greater than at present, a chain of as many as five large lakes was created, of which Searles Lake was third. The stratigraphic record left in Searles Valley when that lake expanded, contracted, or desiccated is fully revealed by cores taken from beneath the surface of Searles (dry) Lake and partly recorded by sediments cropping out around the edge of the valley. Although this outcrop record is discontinuous, it provides direct evidence of the lake’s water depths during each expansion, which the subsurface record does not. Maximum-depth lakes rose to the 2,280-ft (695 m) contour, the level of the spillway that led overflowing waters to Panamint Valley; that spillway is about 660 ft (200 m) above the present dry-lake surface. Most of this study concerns sediments of the newly described Searles Lake Formation, whose deposition spanned the period between about 150 ka and 2 ka. The outcrop record is documented in six geologic maps (scales: 1:50,000 and 1:10,000). The Searles Lake Formation is divided into seven main units. The depositional intervals of the units that make up the Searles Lake Formation are determined primarily by correlation with subsurface deposits that are dated by radiocarbon ages on organic carbon and U-series dates on salts. Shorelines, the most obvious geologic expressions of former lakes, are abundant around Searles Valley. Erosional shorelines have cut as much as 100 m into brecciated bedrock; depositional shorelines

  4. 75 FR 6696 - Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California

    Science.gov (United States)

    2010-02-10

    ... Fish and Wildlife Service Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central... draft recovery plan for Tidal Marsh Ecosystems of Northern and Central California for public review and... Marsh Ecosystems of Northern and Central California features five endangered species. The biology...

  5. Kinematics of the Eastern California shear zone: Evidence for slip transfer from Owens and Saline Valley fault zones to Fish Lake Valley fault zone

    Science.gov (United States)

    Reheis, M.C.; Dixon, T.H.

    1996-01-01

    Late Quaternary slip rates and satellite-based geodetic data for the western Great Basin constrain regional fault-slip distribution and evolution. The geologic slip rate on the Fish Lake Valley fault zone (the northwest extension of the Furnace Creek fault zone) increases northward from about 3 to 5 mm/yr, in agreement with modeled geodetic data. The increase coincides with the intersections of the Deep Springs fault, connected to the Owens Valley fault zone, and of other faults connected to the Saline Valley fault. The combined geologic and geodetic data suggest that (1) the northwest-striking faults of the Eastern California shear zone north of the Garlock fault are connected by north- to northeast-striking normal faults that transfer slip in a series of right steps, and (2) the amount and distribution of slip among the many faults of this broad, complex plate boundary have changed through time.

  6. Biogeochemical cycling of selenium in the San Joaquin Valley, California, USA

    Science.gov (United States)

    Presser, T.S.; Ohlendorf, H.M.

    1987-01-01

    Subsurface agricultural drainage waters from western San Joaquin Valley, California, were found to contain elevated concentrations of the element selenium in the form of selenate. In 1978, these drainage waters began to replace previous input to Kesterson Reservoir, a pond system within Kesterson National Wildlife Refuge; this substitution was completed by 1982. In the 1983 nesting season, unusual rates of deformity and death in embryos and hatchlings of wild aquatic birds (up to 64% of eared grebe and American coot nests) occurred at the refuge and were attributed to selenium toxicosis. Features necessary for contamination to have taken place included geologic setting, climate, soil type, availability of imported irrigation water, type of irrigation, and the unique chemical properties of selenium. The mechanisms of biogeochemical cycling raise questions about other ecosystems and human exposure.

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

    Science.gov (United States)

    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…

  8. Coping with naturally high levels of soil salinity and boron in the westside of central California

    Science.gov (United States)

    In the Westside of central California, over 200,000 ha exhibit naturally high levels of salinity and boron (B). The Coast Ranges of the west central California evolved from complex folding and faulting of sedimentary and igneous rocks of Mesozoic and Tertiary age. Cretaceous and Tertiary marine sedi...

  9. Map of the Rinconada and Reliz Fault Zones, Salinas River Valley, California

    Science.gov (United States)

    Rosenberg, Lewis I.; Clark, Joseph C.

    2009-01-01

    The Rinconada Fault and its related faults constitute a major structural element of the Salinas River valley, which is known regionally, and referred to herein, as the 'Salinas Valley'. The Rinconada Fault extends 230 km from King City in the north to the Big Pine Fault in the south. At the south end of the map area near Santa Margarita, the Rinconada Fault separates granitic and metamorphic crystalline rocks of the Salinian Block to the northeast from the subduction-zone assemblage of the Franciscan Complex to the southwest. Northwestward, the Rinconada Fault lies entirely within the Salinian Block and generally divides this region into two physiographically and structurally distinct areas, the Santa Lucia Range to the west and the Salinas Valley to the east. The Reliz Fault, which continues as a right stepover from the Rinconada Fault, trends northwestward along the northeastern base of the Sierra de Salinas of the Santa Lucia Range and beyond for 60 km to the vicinity of Spreckels, where it is largely concealed. Aeromagnetic data suggest that the Reliz Fault continues northwestward another 25 km into Monterey Bay, where it aligns with a high-definition magnetic boundary. Geomorphic evidence of late Quaternary movement along the Rinconada and Reliz Fault Zones has been documented by Tinsley (1975), Dibblee (1976, 1979), Hart (1976, 1985), and Klaus (1999). Although definitive geologic evidence of Holocene surface rupture has not been found on these faults, they were regarded as an earthquake source for the California Geological Survey [formerly, California Division of Mines and Geology]/U.S. Geological Survey (CGS/USGS) Probabilistic Seismic Hazards Assessment because of their postulated slip rate of 1+-1 mm/yr and their calculated maximum magnitude of 7.3. Except for published reports by Durham (1965, 1974), Dibblee (1976), and Hart (1976), most information on these faults is unpublished or is contained in theses, field trip guides, and other types of reports

  10. Socioeconomic effects of power marketing alternatives for the Central Valley and Washoe Projects: 2005 regional econmic impact analysis using IMPLAN

    International Nuclear Information System (INIS)

    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 ampersand 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

  11. Preliminary digital geologic maps of the Mariposa, Kingman, Trona, and Death Valley Sheets, California

    International Nuclear Information System (INIS)

    Parts of four 1:250,000-scale geologic maps by the California Department of Natural Resources, Division of Mines and Geology have been digitized for use in hydrogeologic characterization. These maps include the area of California between lat. 35 degree N; Long. 115 degree W and lat. 38 degree N, long. 118 degree W of the Kingman Sheet (Jennings, 1961), Trona Sheet (Jennings and others, 1962), Mariposa Sheet (Strand, 1967), and Death Valley Sheet (Streitz and Stinson, 1974). These digital maps are being released by the US Geological Survey in the ARC/INFO Version 6.1 Export format. The digitized data include geologic unit boundaries, fault traces, and identity of geologic units. The procedure outlined in US Geological Survey Circular 1054 (Soller and others, 1990) was sued during the map construction. The procedure involves transferring hard-copy data into digital format by scanning manuscript maps, manipulating the digital map data, and outputting the data. Most of the work was done using Environmental Systems Research Institute's ARC/INFO software. The digital maps are available in ARC/INFO Rev. 6.1 Export format, from the USGS, Yucca Mountain Project, in Denver, Colorado

  12. Location of virtual wells used for urban (municipal and industrial use) pumpage in the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the virtual wells used for urban (municipal and industrial use) pumpage for the Central Valley Hydrologic Model (CVHM). The Central...

  13. Source and composition of size fractionated aerosols collected in the Central Valley

    Science.gov (United States)

    Allen, G.; Kelly, P. B.; Buchholz, B. A.; Clifford, A.

    2013-12-01

    The Central Valley in California has historically had high levels of atmospheric particulate matter (PM), resulting in significant adverse health effects. The three sources of atmospheric PM in the Central Valley are vehicle exhaust emissions, agricultural activity and residential wood burning. Ambient PM was collected during the winter of 2011 and 2012 in Davis, CA using a DRUM impact analyzer to determine the contributions of the various sources to the size fractionated aerosols. Laser desorption ionization time-of-flight mass spectrometry (LDI-TOF MS) and radiocarbon accelerator mass spectrometry (AMS) were performed on size fractionated atmospheric PM. The results show that as particle size decreases the amount of organic carbon increases. In the smallest size fraction (0.09 - 1.2 μm) the organic carbon encompasses approximately 70% of the LDI-TOF signal intensity. A comparison of the size fraction PM LDI-TOF spectra showed that there was a significant difference in the chemical composition with particle size. Three distinct chemical composition modes were observed in the LDI-TOF analysis: 0.09 to 0.34 μm, 0.34 to 0.56 μm and >0.56 μm. The particles 0.5 μm. The chemical difference in the PM is driven by the large amount of secondary organic aerosol. Dicarboxylic acids, aromatic acids and nitrated aromatics were predominately found in particles human health of these compounds needs to be further explored. The difference in the chemical composition between the respirable and larger PM needs to be considered when associating health effects with PM exposure. The radiocarbon AMS analysis showed that the size fractionated total carbonaceous particulate matter was mainly biogenic in origin, having an average fraction modern (F14C) = 0.753 × 0.006. The F14C from both sample collections were similar and there wasn't a significant change in fraction modern as particle size decreased. The high fraction modern in the small PM points to the secondary organic aerosol

  14. Uranium-series dating of pedogenic carbonates from the Livermore Valley, California

    International Nuclear Information System (INIS)

    A uranium-series dating technique has been applied to pedogenic carbonates from the Livermore Valley in California. The results from geomorphologically distinct Quaternary alluvial units are internally consistent and for one alluvial unit are corroborated by a concordant 14C age for an associated wood fragment. In appropriate situations, age dates for pedogenic carbonates derived using this technique may provide a time stratigraphy for alluvial units and hence provide some limits (minimum age) for last fault movement

  15. Overwintering biology of Culex (Diptera: Culicidae) mosquitoes in the Sacramento Valley of California.

    Science.gov (United States)

    Nelms, Brittany M; Macedo, Paula A; Kothera, Linda; Savage, Harry M; Reisen, William K

    2013-07-01

    At temperate latitudes, Culex (Diptera: Culicidae) mosquitoes typically overwinter as adult females in reproductive arrest and also may serve as reservoir hosts for arboviruses when cold temperatures arrest viral replication. To evaluate their role in the persistence of West Nile virus (WNV) in the Sacramento Valley of California, the induction and termination of diapause were investigated for members of the Culex pipiens (L.) complex, Culex tarsalis Coquillett, and Culex stigmatosoma Dyar under field, seminatural, and experimental conditions. All Culex spp. remained vagile throughout winter, enabling the collection of 3,174 females and 1,706 males from diverse habitats during the winters of 2010-2012. Overwintering strategies included both quiescence and diapause. In addition, Cx. pipiens form molestus Forskäl females remained reproductively active in both underground and aboveground habitats. Some blood-fed, gravid, and parous Cx. tarsalis and Cx. pipiens complex females were collected throughout the winter period. Under both field and experimental conditions, Cx. tarsalis and Cx. stigmatosoma females exposed to autumnal conditions arrested primary follicular maturation at previtellogenic stage I, with primary to secondary follicular ratios or=stage I-II (host-seeking arrest) or were found in various stages of degeneration. Diapause was initiated in the majority of Cx. tarsalis and Cx. stigmatosoma females by mid-late October and was terminated after the winter solstice, but host-seeking seemed limited by temperature. An accrual of 97.52 +/- 30.7 and 162.85 +/- 79.3 degree-days after the winter solstice was estimated to be necessary for diapause termination in Cx. tarsalis under field and seminatural conditions, respectively. An increase in the proportion of blood-fed Culex females in resting collections occurred concurrently with diapause termination in field populations based on ovarian morphometrics. WNV RNA was detected in one pool of 18 males and in a

  16. The Association of Ambient Air Pollution and Traffic Exposures With Selected Congenital Anomalies in the San Joaquin Valley of California

    OpenAIRE

    Padula, Amy M.; Tager, Ira B.; Carmichael, Suzan L.; Hammond, S. Katharine; Lurmann, Frederick; Shaw, Gary M.

    2013-01-01

    Congenital anomalies are a leading cause of infant mortality and are important contributors to subsequent morbidity. Studies suggest associations between environmental contaminants and some anomalies, although evidence is limited. We aimed to investigate whether ambient air pollutant and traffic exposures in early gestation contribute to the risk of selected congenital anomalies in the San Joaquin Valley of California, 1997–2006. Seven exposures and 5 outcomes were included for a total of 35 ...

  17. Tectonic map of the Death Valley ground-water model area, Nevada and California

    International Nuclear Information System (INIS)

    The purpose of this map is to provide tectonic interpretations in the Death Valley ground-water model area to be incorporated into a transient ground-water flow model by the U.S. Geological Survey (D'Agnese, 2000; D'Agnese and Faunt, 1999; Faunt and others, 1999; and O'Brien and others, 1999). This work has been conducted in collaboration with the U.S. Department of Energy in order to assess regional ground-water flow near the Nevada Test Site (NTS) and the potential radioactive waste repository at Yucca Mountain. The map is centered on the NTS and its perimeter encircles the entire boundary of the numerical flow model area, covering a total area of 57,000 square kilometers. This tectonic map is a derivative map of the geologic map of the Death Valley ground-water model, Nevada and California (Workman and others, 2002). Structures portrayed on the tectonic map were selected from the geologic map based upon several criteria including amount of offset on faults, regional significance of structures, fault juxtaposition of rocks with significantly different hydrologic properties, and the hydrologic properties of the structures themselves. Inferred buried structures in the basins were included on the map (blue and light blue dotted lines) based on interpretation of geophysical data (Ponce and others, 2001; Ponce and Blakely, 2001; Blakely and Ponce, 2001). In addition, various regional trends of fault zones have been delineated which are composed of multiple smaller scale features. In some cases, these structures are deeply buried and their location is based primarily on geophysical evidence. In all cases, these zones (shown as broad red and blue stippled bands on the map) are significant structures in the region. Finally, surface exposures of Precambrian crystalline rocks and igneous intrusions of various ages are highlighted (red and blue patterns) on the map; these rocks generally act as barriers to groundwater flow unless significantly fractured

  18. Calibration of numerical models for small debris flows in Yosemite Valley, California, USA

    Directory of Open Access Journals (Sweden)

    P. Bertolo

    2005-01-01

    Full Text Available This study compares documented debris flow runout distances with numerical simulations in the Yosemite Valley of California, USA, where about 15% of historical events of slope instability can be classified as debris flows and debris slides (Wieczorek and Snyder, 2004. To model debris flows in the Yosemite Valley, we selected six streams with evidence of historical debris flows; three of the debris flow deposits have single channels, and the other three split their pattern in the fan area into two or more channels. From field observations all of the debris flows involved coarse material, with only very small clay content. We applied the one dimensional DAN (Dynamic ANalysis model (Hungr, 1995 and the two-dimensional FLO-2D model (O'Brien et al., 1993 to predict and compare the runout distance and the velocity of the debris flows observed in the study area. As a first step, we calibrated the parameters for the two softwares through the back analysis of three debris- flows channels using a trial-and-error procedure starting with values suggested in the literature. In the second step we applied the selected values to the other channels, in order to evaluate their predictive capabilities. After parameter calibration using three debris flows we obtained results similar to field observations We also obtained a good agreement between the two models for velocities. Both models are strongly influenced by topography: we used the 30 m cell size DTM available for the study area, that is probably not accurate enough for a highly detailed analysis, but it can be sufficient for a first screening.

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

    OpenAIRE

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

  20. 76 FR 41745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-07-15

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... Valley Unified Air Pollution Control District portion of the California State Implementation Plan (SIP... Valley Unified Air Pollution Control District (SJVUAPCD) Rule 4682, Polystyrene, Polyethylene,...

  1. Spatial and temporal epidemiology of infectious laryngotracheitis in central California: 2000-2012.

    Science.gov (United States)

    Pitesky, Maurice; Chin, R P; Carnaccini, S; Sentíes-Cué, C G; Charlton, B; Woolcock, P R; Shivaprasad, H L

    2014-12-01

    In October of 2005 an outbreak of a vaccine-like strain of infectious laryngotracheitis (ILT), indistinguishable from the chicken embryo origin (CEO)-like vaccine strains, was detected by routine passive surveillance in the Central Valley of California, U. S. A. In response, a highly coordinated industry effort by two companies led to a significant decrease in the incidence of ILT over the same geographic region between 2008-2012. In order to understand the geographic and temporal spread of ILT in California before and after the outbreak, Global Information Systems (GIS) mapping coupled with spatial, temporal, and spatial- temporal statistics were used to identify retrospective and prospective low-rate clustering (i.e., less ILT than statistically expected) and high-rate clustering (i.e., more ILT than statistically expected) of ILT spatially and temporally. Results showed two high-rate retrospective spatial-temporal clusters and one low-rate prospective spatial-temporal cluster which were all statistically significant (P CEO-based vaccine in the identified high rate spatial-temporal clusters should be avoided and other vaccine alternatives considered in order to avoid repeat outbreaks in those areas. This should especially be followed during the winter months of December, January, and February, which were found to have the highest prevalence of ILT (P role in the spread of ILT in one of the two high rate spatial-temporal clusters. PMID:25619000

  2. California GAMA Program: Sources and Transport of Nitrate in Groundwater in the Livermore Valley Basin, California

    International Nuclear Information System (INIS)

    A critical component of the State Water Resource Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) Program is to assess the major threats to groundwater resources that supply drinking water to Californians (Belitz et al., 2004). Nitrate concentrations approaching and greater than the maximum contaminant level (MCL) are impairing the viability of many groundwater basins as drinking water sources Source attribution and nitrate fate and transport are therefore the focus of special studies under the GAMA program. This report presents results of a study of nitrate contamination in the aquifer beneath the City of Livermore, where high nitrate levels affect both public supply and private domestic wells. Nitrate isotope data are effective in determining contaminant sources, especially when combined with other isotopic tracers such as stable isotopes of water and tritium-helium ages to give insight into the routes and timing of nitrate inputs to the flow system. This combination of techniques is demonstrated in Livermore, where it is determined that low nitrate reclaimed wastewater predominates in the northwest, while two flowpaths with distinct nitrate sources originate in the southeast. Along the eastern flowpath, (delta)15N values greater than 10(perthousand) indicate that animal waste is the primary source. Diminishing concentrations over time suggest that contamination results from historical land use practices. The other flowpath begins in an area where rapid recharge, primarily of low nitrate imported water (identified by stable isotopes of water and a tritium-helium residence time of less than 1 year), mobilizes a significant local nitrate source, bringing groundwater concentrations above the MCL of 45 mg NO3 L-1. In this area, artificial recharge of imported water via local arroyos induces flux of the contaminant to the regional aquifer. The low (delta)15N value (3.1(perthousand)) in this location implicates synthetic fertilizer. Geochemical

  3. California GAMA Program: Sources and Transport of Nitrate in Groundwater in the Livermore Valley Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Beller, H; Eaton, G F; Ekwurzel, B E; Esser, B K; Hu, Q; Hudson, G B; Leif, R; McNab, W; Moody-Bartel, C; Moore, K; Moran, J E

    2005-11-18

    A critical component of the State Water Resource Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) Program is to assess the major threats to groundwater resources that supply drinking water to Californians (Belitz et al., 2004). Nitrate concentrations approaching and greater than the maximum contaminant level (MCL) are impairing the viability of many groundwater basins as drinking water sources Source attribution and nitrate fate and transport are therefore the focus of special studies under the GAMA program. This report presents results of a study of nitrate contamination in the aquifer beneath the City of Livermore, where high nitrate levels affect both public supply and private domestic wells. Nitrate isotope data are effective in determining contaminant sources, especially when combined with other isotopic tracers such as stable isotopes of water and tritium-helium ages to give insight into the routes and timing of nitrate inputs to the flow system. This combination of techniques is demonstrated in Livermore, where it is determined that low nitrate reclaimed wastewater predominates in the northwest, while two flowpaths with distinct nitrate sources originate in the southeast. Along the eastern flowpath, {delta}{sup 15}N values greater than 10{per_thousand} indicate that animal waste is the primary source. Diminishing concentrations over time suggest that contamination results from historical land use practices. The other flowpath begins in an area where rapid recharge, primarily of low nitrate imported water (identified by stable isotopes of water and a tritium-helium residence time of less than 1 year), mobilizes a significant local nitrate source, bringing groundwater concentrations above the MCL of 45 mg NO{sub 3} L{sup -1}. In this area, artificial recharge of imported water via local arroyos induces flux of the contaminant to the regional aquifer. The low {delta}{sup 15}N value (3.1{per_thousand}) in this location implicates

  4. Neutron activation analysis of archaeological ceramics from the Central Valley and Turrialba, Costa Rica

    International Nuclear Information System (INIS)

    Neutron activation analysis of 56 ceramic samples is oriented toward a better understanding of the interaction and autonomy among late Period V (A.D. 500-1000) and Period VI (A.D. 1000-1550) societies in the Central Valley and Turrialba. Samples are selected from three sites, Guayabo, Agua Caliente and La Ribera, the samples correspond to (1) local types and (2) polychrome types considered trade goods coming from Guanacaste/Nicoya. Data have supported the Guanacaste-Nicoyan origen of the polychrome pottery. Regarding the Central Valley and Turrialba local types, very little evidence was found for their exchange among communities. This result is explicable on the basis of political autonomy and economic autarky of first-tier chiefdom sites such as Agua Caliente and Guayabo. (author)

  5. Ground-water discharge determined from estimates of evapotranspiration, Death Valley regional flow system, Nevada and California

    Science.gov (United States)

    Laczniak, Randell J.; Smith, J. LaRue; Elliott, Peggy E.; DeMeo, Guy A.; Chatigny, Melissa A.; Roemer, Gaius J.

    2001-01-01

    The Death Valley regional flow system (DVRFS) is one of the larger ground-water flow systems in the southwestern United States and includes much of southern Nevada and the Death Valley region of eastern California. Centrally located within the ground-water flow system is the Nevada Test Site (NTS). The NTS, a large tract covering about 1,375 square miles, historically has been used for testing nuclear devices and currently is being studied as a potential repository for the long-term storage of high-level nuclear waste generated in the United States. The U.S. Department of Energy, as mandated by Federal and State regulators, is evaluating the risk associated with contaminants that have been or may be introduced into the subsurface as a consequence of any past or future activities at the NTS. Because subsurface contaminants can be transported away from the NTS by ground water, components of the ground-water budget are of great interest. One such component is regional ground-water discharge. Most of the ground water leaving the DVRFS is limited to local areas where geologic and hydrologic conditions force ground water upward toward the surface to discharge at springs and seeps. Available estimates of ground-water discharge are based primarily on early work done as part of regional reconnaissance studies. These early efforts covered large, geologically complex areas and often applied substantially different techniques to estimate ground-water discharge. This report describes the results of a study that provides more consistent, accurate, and scientifically defensible measures of regional ground-water losses from each of the major discharge areas of the DVRFS. Estimates of ground-water discharge presented in this report are based on a rigorous quantification of local evapotranspiration (ET). The study identifies areas of ongoing ground-water ET, delineates different ET areas based on similarities in vegetation and soil-moisture conditions, and determines an ET rate for

  6. Ground-water discharge determined from estimates of evapotranspiration, Death Valley regional flow system, Nevada and California

    International Nuclear Information System (INIS)

    The Death Valley regional flow system (DVRFS) is one of the larger ground-water flow systems in the southwestern United States and includes much of southern Nevada and the Death Valley region of eastern California. Centrally located within the ground-water flow system is the Nevada Test Site (NTS). The NTS, a large tract covering about 1,375 square miles, historically has been used for testing nuclear devices and currently is being studied as a potential repository for the long-term storage of high-level nuclear waste generated in the United States. The U.S. Department of Energy, as mandated by Federal and State regulators, is evaluating the risk associated with contaminants that have been or may be introduced into the subsurface as a consequence of any past or future activities at the NTS. Because subsurface contaminants can be transported away from the NTS by ground water, components of the ground-water budget are of great interest. One such component is regional groundwater discharge. Most of the ground water leaving the DVRFS is limited to local areas where geologic and hydrologic conditions force ground water upward toward the surface to discharge at springs and seeps. Available estimates of ground-water discharge are based primarily on early work done as part of regional reconnaissance studies. These early efforts covered large, geologically complex areas and often applied substantially different techniques to estimate ground-water discharge. This report describes the results of a study that provides more consistent, accurate, and scientifically defensible measures of regional ground-water losses from each of the major discharge areas of the DVRFS. Estimates of ground-water discharge presented in this report are based on a rigorous quantification of local evapotranspiration (ET). The study identifies areas of ongoing ground-water ET, delineates different ET areas based on similarities in vegetation and soil-moisture conditions, and determines an ET rate for

  7. Geomorphology and Tectonics at the Intersection of Silurian and Death Valleys, Southern California - 2005 Guidebook Pacific Cell Friends of the Pleistocene

    Science.gov (United States)

    Miller, David M.; Valin, Zenon C.

    2007-01-01

    This publication describes results from new regional and detailed surficial geologic mapping, combined with geomorphologic, geochronologic, and tectonic studies, in Silurian Valley and Death Valley, California. The studies address a long-standing problem, the tectonic and geomorphic evolution of the intersection between three regional tectonic provinces: the eastern California shear zone, the Basin and Range region of southern Nevada and adjacent California, and the eastern Mojave Desert region. The chapters represent work presented on the 2005 Friends of the Pleistocene field trip and meeting as well as the field trip road log.

  8. Contours of Corcoran Clay Thickness in feet by Page (1986) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the thickness of the Corcoran Clay Member of the Tulare Formation. The complex hydrologic system of the Central Valley is simulated...

  9. Contours of Corcoran Clay Depth in feet from Page (1986) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the depth of the Corcoran Clay Member of the Tulare Formation. The complex hydrologic system of the Central Valley is simulated using...

  10. Status of Fruit Farming in Central Valley of Khyber Pakhtunkhwa

    Directory of Open Access Journals (Sweden)

    Nisar Ali Shah,

    2014-10-01

    Full Text Available This retrospective study was conducted in four districts of Khyber Pakhtunkhwa namely Charsadda, Nowshera, Mardan and Peshawar during January February, 2013 to examine the status and factors affecting fruit orchards. A total of Sixty four fruit orchards growers were interviewed on the basis of land acquisition. Data indicates that farmer areas for citrus and planted Stone fruit such as peach, plum and apricot were declined in the last 10 years while the area under pear and loquat were increased. The study results also indicate that a number of factors were affecting fruit orchards. These problems were ranked as (1 diseases/insects, followed by (2 high price, (3 water shortage problem, (4 adulteration in inputs, (5 marketing problem and (6 non-availability of credit. It is concluded that various factors are responsible for the decline in production of fruit orchards. It is thus, recommended that agriculture department should regularly disseminate technical-know-how regarding improved fruit orchards management practices through training, field days and workshop and other awareness programmes for fruit orchards growers. The government should also keep check and balance on price and quality of inputs to encourage fruit orchard growers to increase their production.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yan; Fan, Jiwen; Leung, Lai-Yung R.; Zhao, Chun; Li, Zhanqing; Rosenfeld, Daniel

    2016-02-15

    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.

  12. Hydrogeologic map of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset represents the surface hydrogeology of an approximately 45,000 square-kilometer area of the Death Valley regional ground-water flow system...

  13. Subregions of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the subregions of the transient ground-water flow model of the Death Valley regional ground-water flow system (DVRFS). Subregions are...

  14. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: SOCECON (Socioeconomic Resource Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains socioeconomic resource data for the following types of locations in Central California: access, airport, aquaculture, beach, boat ramp, USCG...

  15. Geologic Map of the Warm Spring Canyon Area, Death Valley National Park, Inyo County, California, With a Discussion of the Regional Significance of the Stratigraphy and Structure

    Science.gov (United States)

    Wrucke, Chester T.; Stone, Paul; Stevens, Calvin H.

    2007-01-01

    Warm Spring Canyon is located in the southeastern part of the Panamint Range in east-central California, 54 km south of Death Valley National Park headquarters at Furnace Creek Ranch. For the relatively small size of the area mapped (57 km2), an unusual variety of Proterozoic and Phanerozoic rocks is present. The outcrop distribution of these rocks largely resulted from movement on the east-west-striking, south-directed Butte Valley Thrust Fault of Jurassic age. The upper plate of the thrust fault comprises a basement of Paleoproterozoic schist and gneiss overlain by a thick sequence of Mesoproterozoic and Neoproterozoic rocks, the latter of which includes diamictite generally considered to be of glacial origin. The lower plate is composed of Devonian to Permian marine formations overlain by Jurassic volcanic and sedimentary rocks. Late Jurassic or Early Cretaceous plutons intrude rocks of the area, and one pluton intrudes the Butte Valley Thrust Fault. Low-angle detachment faults of presumed Tertiary age underlie large masses of Neoproterozoic dolomite in parts of the area. Movement on these faults predated emplacement of middle Miocene volcanic rocks in deep, east-striking paleovalleys. Excellent exposures of all the rocks and structural features in the area result from sparse vegetation in the dry desert climate and from deep erosion along Warm Spring Canyon and its tributaries.

  16. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: REPTILEL (Reptile and Amphibian Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for amphibians and reptiles in Central California. Vector lines in this data set represent general stream...

  17. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, intertidal/subtidal, and terrestrial invertebrate species in Central California. Vector...

  18. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: HABITATS (Habitat Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for benthic habitats in Central California. Vector polygons in this data set represent kelp and eelgrass...

  19. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and anadromous fish species in Central California. Vector polygons in this data set...

  20. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, pelagic birds, and shorebirds in Central California. Vector points...

  1. Net infiltration of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Recharge in the Death Valley regional ground-water flow system (DVRFS) was estimated from net infiltration simulated by Hevesi and others (2003) using a...

  2. Field Trial of Distributed Acoustic Sensing Using Active Sources at Garner Valley, California

    Science.gov (United States)

    Wang, H. F.; Lord, N. E.; Chalari, A.; Lancelle, C.; Baldwin, J. A.; Castongia, E.; Fratta, D.; Nigbor, R. L.; Karaulanov, R.

    2014-12-01

    An optical fiber Distributed Acoustic Sensor array was deployed in a shallow trench at the site of the Garner Valley Downhole Array (GVDA) in southern California. The site was operated as a collaborator of the Network for Earthquake Engineering Simulation (NEES) by UCSB. The fiber-optic cable layout approximated a rectangle whose dimensions were roughly 160 meters by 80 meters. The layout included two subdiagonals to provide a variety of orientations of the cable relative to source locations. The study included different seismic sources deployed at a number of surveyed positions: a 45 kN shear shaker operated at the site by NEES@UCLA, a portable 450 N shaker, a small Vibroseis truck, and hammer blows on a steel plate to map cable locations. Several dozen separate tests were recorded in which each test typically included ten repeats. The data were utilized for several studies. First, the characteristics of the recorded signals were analyzed for directivity and sensitivity of the cable response (Lancelle et al., 2014, this meeting). The DAS system recorded dynamic ground events in the direction of the cable and hence comparisons with geophones required signal processing. The one-meter spacing of DAS traces could be well correlated over distances of a few meters. Second, swept-sine sources were used to obtain surface-wave velocity dispersion to determine near-surface shear-wave velocity distribution using Multispectral Analysis of Surface Waves (MASW) (Baldwin et al., 2014, this meeting). The results were in good agreement with previous Vibroseis results at the site (Stokoe et al. 2004). Third, a new method for time-frequency filtering was developed for extracting the surface-wave phase velocities from uncorrelated receiver traces (Lord et al., 2014, this meeting).

  3. Population Structure of Xylella fastidiosa Associated with Almond Leaf Scorch Disease in the San Joaquin Valley of California.

    Science.gov (United States)

    Lin, Hong; Islam, Md Sajedul; Cabrera-La Rosa, Juan C; Civerolo, Edwin L; Groves, Russell L

    2015-06-01

    Xylella fastidiosa causes disease in many commercial crops, including almond leaf scorch (ALS) disease in susceptible almond (Prunus dulcis). In this study, genetic diversity and population structure of X. fastidiosa associated with ALS disease were evaluated. Isolates obtained from two almond orchards in Fresno and Kern County in the San Joaquin Valley of California were analyzed for two successive years. Multilocus simple-sequence repeat (SSR) analysis revealed two major genetic clusters that were associated with two host cultivars, 'Sonora' and 'Nonpareil', respectively, regardless of the year of study or location of the orchard. These relationships suggest that host cultivar selection and adaptation are major driving forces shaping ALS X. fastidiosa population structure in the San Joaquin Valley. This finding will provide insight into understanding pathogen adaptation and host selection in the context of ALS disease dynamics. PMID:25807309

  4. ZONE package of the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the model grid, active cells in model layers 2 and 3, and geologic province arrays of the ZONE package used in the transient hydrologic...

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

    Science.gov (United States)

    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. Potential for using the Upper Coachella Valley ground-water basin, California, for storage of artificially recharged water

    Science.gov (United States)

    Mallory, Michael J.; Swain, Lindsay A.; Tyley, Stephen J.

    1980-01-01

    This report presents a preliminary evaluation of the geohydrologic factors affecting storage of water by artificial recharge in the upper Coachella Valley, Calif. The ground-water basin of the upper Coachella Valley seems to be geologically suitable for large-scale artificial recharge. A minimum of 900 ,000 acre-feet of water could probably be stored in the basin without raising basinwide water levels above those that existed in 1945. Preliminary tests indicate that a long-term artificial recharge rate of 5 feet per day may be feasible for spreading grounds in the basin if such factors as sediment and bacterial clogging can be controlled. The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Water Project water in order to help meet maximum annual entitlements to water project contractors. (USGS)

  7. Geophysical studies of Mono Lake, east-central California

    Science.gov (United States)

    Athens, N. D.; Ponce, D. A.

    2012-12-01

    Magnetic and gravity investigations were undertaken in Mono Lake, California to study regional crustal structures and to aid understanding the geologic framework of Mono Lake, in particular regarding potential geothermal resources and volcanic hazards throughout Mono Basin. Recent geophysical surveys included over 600 line-kilometers of high-resolution ship-borne magnetometer data that augmented existing airborne data, 22 line-kilometers of ground magnetic data that were collected along six traverses across Paoha Island, 56 gravity stations that were collected on Paoha and Negit Islands, and 28 rock samples that were collected for physical property data. Magnetic highs in the study area occur to the east and west of Mono Lake, where pre-Tertiary basement is exposed. Magnetic data indicate that Mono Lake itself is dominated by three prominent magnetic anomalies that are from west to east: a magnetic high along the northwest part of the lake associated with the moderately magnetic basalt cinder cone at Black Point, a magnetic high associated with the young volcanic centers at Paoha and Negit Islands, and a broad magnetic high along the eastern margin of the lake probably associated with moderately magnetic granitic basement rocks at depth. Because volcanic rocks exposed at the surface of Paoha and Negit Islands are only weakly magnetic, magnetic data suggest that more mafic volcanic rocks probably occur at depth and are the source of the anomaly. The linear and steep magnetic gradient across the eastern part of the lake may reflect a fault. A fault may also be imaged in the northeastern part of the lake, where a possible laterally offset magnetic anomaly may be present. Within Mono Lake, gravity station control is poor because land-based gravity stations are limited to Paoha and Negit Islands. The gravity low in the basin reflects a moderately deep sedimentary basin filled with low density lacustrine and volcanic deposits. Isostatic gravity data indicate the central

  8. Assessment of geothermal development in the Imperial Valley of California. Volume 1. Environment, health, and socioeconomics

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D. (ed.)

    1980-07-01

    Utilization of the Imperial Valley's geothermal resources to support energy production could be hindered if environmental impacts prove to be unacceptable or if geothermal operations are incompatible with agriculture. To address these concerns, an integrated environmental and socioeconomic assessment of energy production in the valley was prepared. The most important impacts examined in the assessment involved air quality changes resulting from emissions of hydrogen sulfide, and increases in the salinity of the Salton Sea resulting from the use of agricultural waste waters for power plant cooling. The socioeconomics consequences of future geothermal development will generally be beneficial. (MHR)

  9. Economic and policy implications of public support for ethanol production in California's San Joaquin Valley

    International Nuclear Information System (INIS)

    The US Environmental Protection Agency requires that only oxygenated gasoline may be sold in regions that are not in compliance with national air quality standards. Several non-attainment regions are located in California, and most of the gasoline sold there is oxygenated with methyl tertiary butyl ether (MTBE). California is planning to discontinue the use of MTBE in gasoline by January 2004. This policy will generate greater demand for ethanol, which is the leading substitute for MTBE. Most of the ethanol required in California will be imported from other states, unless California develops an ethanol production industry. The costs of producing ethanol in California may exceed the benefits, unless substantial value is attributed to non-market, public goods, such as maintaining agriculture and reducing unemployment in rural areas. We examine the firm-level economics of using corn and other agricultural products to produce ethanol in California, and the potential regional economic impacts of building and operating an ethanol plant. The cost of production is greater than the current price of ethanol for all of the feedstocks we consider. Production generates economic activity, but at current prices for inputs and outputs, substantial subsidies will be required to encourage firms to produce ethanol in California

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

    Science.gov (United States)

    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. Spectro-microscopic measurements of carbonaceous aerosol aging in Central California

    Directory of Open Access Journals (Sweden)

    R. C. Moffet

    2013-04-01

    Full Text Available Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES was designed to study carbonaceous aerosols in the natural environment of Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of pollution accumulation event (27–29 June 2010, when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX and scanning transmission X-ray microscopy coupled with near edge X-ray absorption spectroscopy (STXM/NEXAFS were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than ~50 nm diameter increased with plume age as did the organic mass per particle. Comparison of the CARES spectro-microscopic data set with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that individual particles in Mexico City contained twice as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (30% was larger than at the CARES urban site (10% and the most aged samples from CARES contained less carbon-carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol precursors. The detailed results provided by these spectro

  12. Greenhouse gas sources in the southern San Joaquin Valley of California derived from Positive Matrix Factorization of CalNex 2010 observations

    Science.gov (United States)

    Guha, A.; Gentner, D. R.; Weber, R.; Baer, D. S.; Gardner, A.; Provencal, R. A.; Goldstein, A. H.

    2012-12-01

    Quantifying the contributions of methane (CH4) and nitrous oxide (N2O) emission from sources in the southern San Joaquin valley is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law (California Global Warming Solutions Act 2006) implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The "bottom-up" emission factors for CH4 and N2O have large uncertainties and there is a lack of adequate "top-down" measurements to characterize emission rates from sources. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agriculture and industry intensive region with large concentration of dairies, refineries and active oil fields which are known CH4 sources while agricultural soil management and vehicular combustion are known sources of N2O. In summer of 2010, GHG sources in the southern San Joaquin valley were investigated as part of the CalNex (California at the Nexus of Air Quality and Climate Change) campaign. Measurements of GHG gases (CO2, CH4, and N2O) and the combustion tracer CO were performed at the Bakersfield super-site over a period of six weeks using fast response lasers based on cavity enhanced absorption spectroscopy (LGR Inc. CA). Coincident measurements of hundreds of volatile organic compounds (VOCs) served as anthropogenic and biogenic tracers of the GHG sources at local and regional levels. We present the results of Positive Matrix Factorization (PMF) analysis applied to the GHGs, CO, and 60 VOCs to define dominant source emission profiles. Seven source factors were identified and used to attribute the contribution of regional sources to enhancements above the background. Dairy operations were found to be the largest CH4 source in the region with approximately 80% of the regional emissions attributed to the 'dairy' factor. Factors dominated

  13. Physical measurements including temperature profiles of coastal Waters off Central California in October 2006 (NODC Accession 0019214)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical measurements of Coastal Waters off Central California in October 2006. Naval Postgraduate School, Monterey, California, Technical Report NPS-OC-07-002....

  14. Variability of indicator values for ozone production sensitivity: a model study in Switzerland and San Joaquin Valley (California)

    International Nuclear Information System (INIS)

    The threshold values of indicator species and ratios delineating the transition between NOx and VOC sensitivity of ozone formation are assumed to be universal by various investigators. However, our previous studies suggested that threshold values might vary according to the locations and conditions. In this study, threshold values derived from various model simulations at two different locations (the area of Switzerland by UAM Model and San Joaquin Valley of Central California by SAQM Model) are examined using a new approach for defining NOx and VOC sensitive regimes. Possible definitions for the distinction of NOx and VOC sensitive ozone production regimes are given. The dependence of the threshold values for indicators and indicator ratios such as NOy, O3/NOz, HCHO/NOy, and H2O2/HNO3 on the definition of NOx and VOC sensitivity is discussed. Then the variations of threshold values under low emission conditions and in two different days are examined in both areas to check whether the models respond consistently to changes in environmental conditions. In both cases, threshold values are shifted similarly when emissions are reduced. Changes in the wind fields and aging of the photochemical oxidants seem to cause the day-to-day variation of the threshold values. O3/NOz and HCHO/NOy indicators are predicted to be unsatisfactory to separate the NOx and VOC sensitive regimes. Although NOy and H2O2/HNO3 provide a good separation of the two regimes, threshold values are affected by changes in the environmental conditions studied in this work. (author)

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

    Science.gov (United States)

    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

  16. Chemical composition data and calculated aquifer temperature for selected wells and springs of Honey Lake Valley, California

    Science.gov (United States)

    Mariner, R.H.; Presser, T.S.; Evans, William C.

    1976-01-01

    Major element, minor element, and gas composition data are tabulated for 15 springs and wells in Honey Lake Valley, California. Wendel and Amedee hot springs issue Na-S04-C1 waters at boiling or near boiling temperatures; the remaining springs and wells issue Na-HC03 waters at temperatures ranging from 14 to 33 deg C. Gases escaping from the hot springs are principally nitrogen with minor amounts of methane. The geothermometers calculated from the chemical data are also tabulated for each spring. (Woodard-USGS)

  17. Earthquakes in Central California, 1980-1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There have been many earthquake occurrences in central California. This set of slides shows earthquake damage from the following events: Livermore, 1980, Coalinga,...

  18. Central California 3 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3-second Central California Elevation Grid provides bathymetric data in ASCII raster format of 3-second resolution in geographic coordinates. This grid is...

  19. Near real-time monitoring of surface deformation at Long Valley Caldera, California (Invited)

    Science.gov (United States)

    Ji, K.; Llenos, A. L.; Herring, T.

    2013-12-01

    Continuous monitoring of volcanic activity enables us to detect changes from usual activity, issue alerts of impending eruptions and thereby reduce volcanic risk. We have developed a near real-time monitoring tool for surface deformation: the Targeted Projection Operator (TPO). TPO is simple, fast, and easily applied whenever new data are available. With Global Positioning System (GPS) data, we have used TPO for continuous monitoring of surface deformation in the Long Valley Caldera (LVC) region in eastern California. TPO projects GPS position time series onto a target spatial pattern and obtains the amplitude of the projection at each epoch. For this, we assume that a deformation event (i.e., an inflationary or deflationary event) has the same spatial pattern as past events but with possibly different amplitude. This assumption is reasonable for the recent quiet phase in LVC because the 2007-2009 inflation is similar to the 2009-2010 deflation with respect to the deformation pattern. We selected horizontal pattern of the 2009-2010 event along which the GPS data are projected to recover the time-varying amplitudes. Large changes in amplitude imply changes in strength of the event. An anomalous change can be detected by comparing with amplitudes during relatively quiet time periods. Growing misfits between the TPO spatial pattern and the spatial variations of the GPS pattern, indicate changes in the deformation mechanism which can then be explored to assess whether potentially new mechanisms are developing. So far this has not been the case for LVC; the current spatial patterns of deformation match the shape deduced for the 2007-2009 inflation event. TPO shows that LVC has experienced inflation since late 2011 although the rate briefly slowed down in May and October 2012 and has started to slow again since June 2013. The rate of this event is about four times faster than the 2007-2009 inflation event and is consistent with a Mogi source located beneath the resurgent

  20. Socioeconomic effects of power marketing alternatives for the Central Valley and Washoe Projects: 2005 regional econmic impact analysis using IMPLAN

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Perspective with Landsat Overlay: Antelope Valley, California

    Science.gov (United States)

    2000-01-01

    Antelope Valley is bounded by two of the most active faults in California: the Garlock fault, which fronts the distant mountains in this view, and the San Andreas fault, part of which is seen bounding the mountains in the left foreground. In this view, Antelope Valley is in the foreground, the Tehachapi Mountains form the left skyline, and ranges within the southernmost Sierra Nevada form the right skyline. Antelope Valley is directly north of Los Angeles and is the westernmost part of the Mojave Desert. It is a closed basin. Stream flow here ends at Rosamond and Rogers dry lakes, which appear bright white. Dry lakes like these are common where tectonic activity raises and lowers parts of the Earth's crust, and thus the topographic surface, faster than stream flow can fill depressions with water, and then overflow and cut escape channels to other basins and eventually to the sea. The Sierra Nevada, the Tehachapi, and other mountains generally to the west create a rain shadow desert here. Thus, the area definitely has the active tectonics and low rainfall combination that leads to closed basin topography.This perspective view was generated by draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission. Shading of the SRTM elevation model was added to enhance topographic appearance. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.The elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three

  2. Polluting of winter convective clouds upon transition from ocean inland over central California: Contrasting case studies

    Science.gov (United States)

    Rosenfeld, Daniel; Chemke, Rei; Prather, Kimberly; Suski, Kaitlyn; Comstock, Jennifer M.; Schmid, Beat; Tomlinson, Jason; Jonsson, Haflidi

    2014-01-01

    In-situ aircraft measurements of aerosol chemical and cloud microphysical properties were conducted during the CalWater campaign in February and March 2011 over the Sierra Nevada Mountains and the coastal waters of central California. The main objective was to elucidate the impacts of aerosol properties on clouds and precipitation forming processes. In order to accomplish this, we compared contrasting cases of clouds that ingested aerosols from different sources. The results showed that clouds containing pristine oceanic air had low cloud drop concentrations and started to develop rain 500 m above their base. This occurred both over the ocean and over the Sierra Nevada, mainly in the early morning when the radiatively cooled stable continental boundary layer was decoupled from the cloud base. Supercooled rain dominated the precipitation that formed in growing convective clouds in the pristine air, up to the - 21 °C isotherm level. A contrasting situation was documented in the afternoon over the foothills of the Sierra Nevada, when the clouds ingested high pollution aerosol concentrations produced in the Central Valley. This led to slow growth of the cloud drop effective radius with height and suppressed and even prevented the initiation of warm rain while contributing to the development of ice hydrometeors in the form of graupel. Our results show that cloud condensation and ice nuclei were the limiting factors that controlled warm rain and ice processes, respectively, while the unpolluted clouds in the same air mass produced precipitation quite efficiently. These findings provide the motivation for deeper investigations into the nature of the aerosols seeding clouds.

  3. The Emergence of Homo sapiens in South Asia: The Central Narmada Valley as Witness

    Directory of Open Access Journals (Sweden)

    Anek R. Sankhyan

    2013-04-01

    Full Text Available :The emergence of anatomically modern Homo sapiens in South Asia is hotly debated due to a great gap in fossil record. A solitary partial cranium from Hathnora dated around 250 Kya is debated and conveniently interpreted as "evolved" Homo erectus or "archaic" Homo sapiens or Homo heidelbergensis or even Homo indet. Cranial fossils of Pre-Toba or post- Toba anatomically modern Homo sapiens are unknown barring the very late 30 Kya modern human remains from Sri Lanka. The present paper reviews the scenario of human evolution in South Asia with special reference to the cranial and recent postcranial fossil findings by the author in association with the archaeological evidences from Central Narmada valley. It is concluded that the Narmada fossils and archaeological findings support the presence of three hominins- two 'archaic' and one 'early modern'. The Mode 2 Acheulian hominin represented by the calvarium and the femur was a 'large-bodied' species akin to Homo heidelbergensis. It appeared first in the Central Narmada valley and was followed by a 'small-bodied' Mode 3 archaic type represented by two clavicles and the 9th rib, provisionally named here as Homo narmadensis. It likely continued and attained anatomical and behavioural modernity in South Asia as attested by the humerus and bone artifacts, and diversified to various short-bodied indigenous populations of South Asia supported by the genomic evidences.

  4. Future impacts of distributed power generation on ambient ozone and particulate matter concentrations in the San Joaquin Valley of California.

    Science.gov (United States)

    Vutukuru, Satish; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald

    2011-12-01

    Distributed power generation-electricity generation that is produced by many small stationary power generators distributed throughout an urban air basin-has the potential to supply a significant portion of electricity in future years. As a result, distributed generation may lead to increased pollutant emissions within an urban air basin, which could adversely affect air quality. However, the use of combined heating and power with distributed generation may reduce the energy consumption for space heating and air conditioning, resulting in a net decrease of pollutant and greenhouse gas emissions. This work used a systematic approach based on land-use geographical information system data to determine the spatial and temporal distribution of distributed generation emissions in the San Joaquin Valley Air Basin of California and simulated the potential air quality impacts using state-of-the-art three-dimensional computer models. The evaluation of the potential market penetration of distributed generation focuses on the year 2023. In general, the air quality impacts of distributed generation were found to be small due to the restrictive 2007 California Air Resources Board air emission standards applied to all distributed generation units and due to the use of combined heating and power. Results suggest that if distributed generation units were allowed to emit at the current Best Available Control Technology standards (which are less restrictive than the 2007 California Air Resources Board standards), air quality impacts of distributed generation could compromise compliance with the federal 8-hr average ozone standard in the region. PMID:22263420

  5. A survey of syrphid predators of Nasonovia ribisnigri in organic lettuce on the central coast of California.

    Science.gov (United States)

    Smith, Hugh A; Chaney, William E

    2007-02-01

    Organic lettuce, Lactuca sativa L., producers on California's Central Coast rely on endemic syrphid flies (Diptera: Syrphidae) to suppress populations of Nasonovia ribisnigri Mosley (Homoptera: Aphididae) and other aphids affecting lettuce. Growers are using various forms of habitat manipulation to enhance biological control. We surveyed syrphids collected from organic romaine in and around the Salinas Valley from March through September 2005 to gain a better understanding of the species responsible for aphid suppression and to examine possible implications for biocontrol. The primary species of syrphid fly reared were Toxomerus marginatus (Say) (39%), Platycheirus stegnus (Say) (27%), Sphaerophoria sulfuripes (Thomson) (13%), and Allograpta obliqua (Say) (10%). Syrphus opinator Osten Sacken (2%), Toxomerus occidentalis (Curran) (1.3%), and Eupeodes volucris Osten Sacken (1%) were less common. Sphaerophoria pyrrhina Bigot, Scaeva pyrastri (L.), Platycheirus obscurus Say, Allograpta exotica Wiedemann, and Eupeodes americanus Wiedemann each made up parasitized by either Diplazon sp. (Hymenoptera: Ichneumonidae) or Pachyneuron sp. (Hymenoptera: Pteromalidae). PMID:17370807

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

    Science.gov (United States)

    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.

  7. Analysis of the Carmel Valley alluvial ground-water basin, Monterey County, California

    Science.gov (United States)

    Kapple, Glenn W.; Mitten, Hugh T.; Durbin, Timothy J.; Johnson, Michael J.

    1984-01-01

    A two-dimensional, finite-element, digital model was developed for the Carmel Valley alluvial ground-water basin using measured, computed, and estimated discharge and recharge data for the basin. Discharge data included evapotranspiration by phreatophytes and agricultural, municipal, and domestic pumpage. Recharge data included river leakage, tributary runoff, and pumping return flow. Recharge from subsurface boundary flow and rainfall infiltration was assumed to be insignificant. From 1974 through 1978, the annual pumping rate ranged from 5,900 to 9,100 acre-feet per year with 55 percent allotted to municipal use principally exported out of the valley, 44 percent to agricultural use, and 1 percent to domestic use. The pumpage return flow within the valley ranged from 900 to 1,500 acre-feet per year. The aquifer properties of transmissivity (about 5,900 feet squared per day) and of the storage coefficient (0.19) were estimated from an average alluvial thickness of 75 feet and from less well-defined data on specific capacity and grain-size distribution. During calibration the values estimated for hydraulic conductivity and storage coefficient for the lower valley were reduced because of the smaller grain size there. The river characteristics were based on field and laboratory analyses of hydraulic conductivity and on altitude survey data. The model is intended principally for simulation of flow conditions using monthly time steps. Time variations in transmissivity and short-term, highrecharge potential are included in the model. The years 1974 through 1978 (including "pre-" and "post-" drought) were selected because of the extreme fluctuation in water levels between the low levels measured during dry years and the above-normal water levels measured during the preceding and following wet years. Also, during this time more hydrologic information was available. Significantly, computed water levels were generally within a few feet of the measured levels, and computed

  8. Post project appraisal of Green Valley Creek, Solano County, California : design and management review

    OpenAIRE

    Martin, Maureen; Fortin, Alex

    2003-01-01

    We assessed the success of Green Valley River Restoration Project, specifically assessing sedimentation and channel stability. The major objectives of the restoration were to provide flood control by constructing a two terraced channel, re-plant riparian corridor with native species, and mitigate for 1.89 acres of seasonal wetland lost to development. We attempted to compare project conditions after a major flow event in 1995 (second year after project completion) with those of the most rece...

  9. Geological study of uranium potential of the Kingston Peak Formation, Death Valley Region, California

    International Nuclear Information System (INIS)

    The results of a geological survey of the Kingston Peak Formation on the western slope of the Panamint Range near Death Valley are discussed. The geology of the Panamint mountains was mapped on topographic base maps of the Telescope Peak and Manly Peak quadrangles. Radiometric suveys of the area were conducted using gamma ray spectrometers. Samples of the conglomerate were analyzed using delayed neutron, neutron activation, atomic absorption, and LECO analysis. It is concluded that uranium mineralization in the Favorable Submember is significant and further exploration is warranted. The monazite-fenotime related uranium and thorium mineralization in the Mountain Girl quartz pebble conglomerate is of no economic interest

  10. Geochemistry of Mesozoic plutons, southern Death Valley region, California: Insights into the origin of Cordilleran interior magmatism

    Science.gov (United States)

    Ramo, O.T.; Calzia, J.P.; Kosunen, P.J.

    2002-01-01

    Mesozoic granitoid plutons in the southern Death Valley region of southeastern California reveal substantial compositional and isotopic diversity for Mesozoic magmatism in the southwestern US Cordillera. Jurassic plutons of the region are mainly calc-alkaline mafic granodiorites with ??Ndi of -5 to -16, 87Sr/86Sri of 0.707-0.726, and 206Pb/204Pbi of 17.5-20.0. Cretaceous granitoids of the region are mainly monzogranites with ??Ndi of -6 to -19, 87Sr/86Sri of 0.707-0.723, and 206Pb/204Pbi of 17.4-18.6. The granitoids were generated by mixing of mantle-derived mafic melts and pre-existing crust - some of the Cretaceous plutons represent melting of Paleoproterozoic crust that, in the southern Death Valley region, is exceptionally heterogeneous. A Cretaceous gabbro on the southern flank of the region has an unuasually juvenile composition (??Ndi -3.2, 87Sr/86Sri 0.7060). Geographic position of the Mesozoic plutons and comparison with Cordillera plutonism in the Mojave Desert show that the Precambrian lithosphere (craton margin) in the eastern Mojave Desert region may consists of two crustal blocks separated by a more juvenile terrane.

  11. The ends of uncertainty: Air quality science and planning in Central California

    Energy Technology Data Exchange (ETDEWEB)

    Fine, James

    2003-09-01

    Air quality planning in Central California is complicated and controversial despite millions of dollars invested to improve scientific understanding. This research describes and critiques the use of photochemical air quality simulation modeling studies in planning to attain standards for ground-level ozone in the San Francisco Bay Area and the San Joaquin Valley during the 1990's. Data are gathered through documents and interviews with planners, modelers, and policy-makers at public agencies and with representatives from the regulated and environmental communities. Interactions amongst organizations are diagramed to identify significant nodes of interaction. Dominant policy coalitions are described through narratives distinguished by their uses of and responses to uncertainty, their exposures to risks, and their responses to the principles of conservatism, civil duty, and caution. Policy narratives are delineated using aggregated respondent statements to describe and understand advocacy coalitions. I found that models impacted the planning process significantly, but were used not purely for their scientific capabilities. Modeling results provided justification for decisions based on other constraints and political considerations. Uncertainties were utilized opportunistically by stakeholders instead of managed explicitly. Ultimately, the process supported the partisan views of those in control of the modeling. Based on these findings, as well as a review of model uncertainty analysis capabilities, I recommend modifying the planning process to allow for the development and incorporation of uncertainty information, while addressing the need for inclusive and meaningful public participation. By documenting an actual air quality planning process these findings provide insights about the potential for using new scientific information and understanding to achieve environmental goals, most notably the analysis of uncertainties in modeling applications. Concurrently

  12. Exploring the potential of co-investments in land management in the Central Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Adimassu Teferi, Z.

    2013-01-01

    Like in any other part of the country, land degradation resulting from water erosion and nutrient depletion     is one of the most challenging problems for farmers in the Central Rift Valley (CRV) of Ethiopia.     Nevertheless, investments in land management t

  13. 75 FR 70020 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    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... on Central Valley Project water conservation best management practices that shall ``* * *...

  14. 78 FR 21414 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    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... an office on Central Valley Project water conservation best management practices that shall...

  15. 75 FR 51058 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-08-18

    ... 12, 2010 (75 FR 18499). By following the link below, reviewers may download the initial data and EPA... Federal Register Notice (75 FR 30393). FOR FURTHER INFORMATION CONTACT: For information on submitting... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

  16. Metamorphism of Greater and Lesser Himalayan rocks exposed in the Modi Khola valley, central Nepal

    Science.gov (United States)

    Martin, Aaron J.; Ganguly, Jibamitra; Decelles, Peter G.

    2010-02-01

    Thermobarometric estimates for Lesser and Greater Himalayan rocks combined with detailed structural mapping in the Modi Khola valley of central Nepal reveal that large displacement thrust-sense and normal-sense faults and ductile shear zones mostly control the spatial pattern of exposed metamorphic rocks. Individual shear zone- or fault-bounded domains contain rocks that record approximately the same peak metamorphic conditions and structurally higher thrust sheets carry higher grade rocks. This spatial pattern results from the kinematics of thrust-sense faults and shear zones, which usually place deeper, higher grade rocks on shallower, lower grade rocks. Lesser Himalayan rocks in the hanging wall of the Ramgarh thrust equilibrated at about 9 kbar and 580°C. There is a large increase in recorded pressures and temperatures across the Main Central thrust. Data presented here suggest the presence of a previously unrecognized normal fault entirely within Greater Himalayan strata, juxtaposing hanging wall rocks that equilibrated at about 11 kbar and 720°C against footwall rocks that equilibrated at about 15 kbar and 720°C. Normal faults occur at the structural top and within the Greater Himalayan series, as well as in Lesser Himalayan strata 175 and 1,900 m structurally below the base of the Greater Himalayan series. The major mineral assemblages in the samples collected from the Modi Khola valley record only one episode of metamorphism to the garnet zone or higher grades, although previously reported ca. 500 Ma concordant monazite inclusions in some Greater Himalayan garnets indicate pre-Cenozoic metamorphism.

  17. Farm Process (FMP) Parameters used in the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the farm-process parameters used in the transient hydrologic model of the Central Valley flow system. The Central Valley encompasses an...

  18. Streamflow-gain- and streamflow-loss data for streamgages in the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains 61 sets of annual streamflow gains and losses between 1961 and 1977 along Central Valley surface-water network for the Central Valley...

  19. Spectro-microscopic measurements of carbonaceous aerosol aging in Central California

    Directory of Open Access Journals (Sweden)

    R. C. Moffet

    2013-10-01

    Full Text Available Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES was designed to study carbonaceous aerosols in the natural environment of the Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of a pollution accumulation event (27–29 June 2010, when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer-controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX and scanning transmission X-ray microscopy coupled with near-edge X-ray absorption spectroscopy (STXM/NEXAFS were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than ~50 nm equivalent circular diameter increased with plume age, as did the organic mass per particle. Comparison of the CARES spectro-microscopic dataset with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that fresh particles in Mexico City contained three times as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (ranging from 16.6 to 47.3% was larger than at the CARES urban site (13.4–15.7%, and the most aged samples from CARES contained fewer carbon–carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol

  20. Virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Abstract: This digital dataset contains the virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  1. Monthly Precipitation Input Data for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly precipitation for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000...

  2. Surface-Water Network for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate...

  3. Grid cells used for Surface-Water Network for the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the segment and reaches for the surface-water network by model cell for the Central Valley Hydrologic Model (CVHM). The Central Valley...

  4. Monthly inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  5. Inflow Locations and Magnitude Input Files to the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the name and location for the inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley...

  6. Community Supported Agriculture is thriving in the Central Valley

    OpenAIRE

    Galt, Ryan E; O'Sullivan, Libby; Beckett, Jessica; Hiner, Colleen C

    2012-01-01

    Community Supported Agriculture operations (CSAs) have grown rapidly in recent years. The original model, in which members support a farming operation by paying for produce in advance and receive a share of the farm's produce in return, has been adapted, with much innovation. Since little research existed on CSAs in the Central Valley, we surveyed and carried out in-depth interviews with 54 CSA farmers and two CSA organizers in the Central Valley and surrounding foothills. Here we focus on fo...

  7. High-resolution aeromagnetic survey of the Mono Basin-Long Valley Caldera region, California

    Science.gov (United States)

    Ponce, D. A.; Mangan, M.; McPhee, D.

    2013-12-01

    A new high-resolution aeromagnetic survey of the Mono Basin-Long Valley Caldera region greatly enhances previous magnetic interpretations that were based on older, low-resolution, and regional aeromagnetic data sets and provides new insights into volcano-tectonic processes. The surveyed area covers a 8,750 km2 NNW-trending swath situated between the Sierra Nevada to the west and the Basin and Range Province to the east. The surveyed area includes the volcanic centers of Mono Lake, Mono-Inyo Craters, Mammoth Mountain, Devils Postpile, and Long Valley Caldera. The NW-trending eastern Sierra frontal fault zone crosses through the study area, including the active Mono Lake, Silver Lake, Hartley Springs, Laurel Creek, and Hilton Creek faults. Over 6,000 line-kilometers of aeromagnetic data were collected at a constant terrain clearance of 150 m, a flight-line spacing of 400 m, and a tie-line spacing of 4 km. Data were collected via helicopter with an attached stinger housing a magnetic sensor using a Scintrex CS-3 cesium magnetometer. In the northern part of the survey area, data improve the magnetic resolution of the individual domes and coulees along Mono Craters and a circular shaped magnetic anomaly that coincides with a poorly defined ring fracture mapped by Kistler (1966). Here, aeromagnetic data combined with other geophysical data suggests that Mono Craters may have preferentially followed a pre-existing plutonic basement feature that may have controlled the sickle shape of the volcanic chain. In the northeastern part of the survey, aeromagnetic data reveal a linear magnetic anomaly that correlates with and extends a mapped fault. In the southern part of the survey, in the Sierra Nevada block just south of Long Valley Caldera, aeromagnetic anomalies correlate with NNW-trending Sierran frontal faults rather than to linear NNE-trends observed in recent seismicity over the last 30 years. These data provide an important framework for the further analysis of the

  8. A multi-isotope (B, Sr, O, H) and age dating (3H-3He, 14C) study of groundwater from Salinas Valley, California

    International Nuclear Information System (INIS)

    This study investigates the chemical and isotopic compositions of groundwater from Salinas Valley, California in order to constrain the origin and rates of groundwater contamination. We use an array of geochemical, environmental isotopes of water (18O/16O, D/H, 3H-3He) and dissolved salts (11B/10B, 87Sr/86Sr, 14C) to establish a reliable conceptual model for the basin. The basin consists of a deep, confined '400-foot aquifer' overlying the '180-foot aquifer' and a perched aquifer, all made up of sand, gravels, clays, and alluvial deposits. Our 3H-3He, 14C, and δ18O results show different replenishment zones and rates in the basin: (1) rapid replenishment (14C concentrations of 72 to 98 pmc) in the perched and 180-foot aquifers in the northern area; (2) fast arrival (15 years) of 18O- and NO3-enriched agriculture-return flows in the unconfined 180-foot aquifer in the central valley; (3) young water recharge (6 to 20 years) fi-om the Salinas River, which is enriched in 18O and D relative to GMWL, occurs in the southern basin; and (4) travel time of >10,000 years (14C = 21.3 PMC) in the deep 400-foot aquifer in the northern area of the valley, indicating pristine slow recharge. We identified several different end-member saline components with distinguishable chemical and isotopic fingerprints: (1) agriculture return flow in the perched aquifer (e.g., high NO3 and SO4, low 87Sr/86Sr 0.7082, δ11B = 19 per mille); (2) salt-water intrusion in the northern basin (e.g., low Na/Cl, marine Br/Cl, high Ca/Mg, δ11B = 17 to 38 per mille, 87Sr/86Sr = 0.7088 to 0.7096; (3) non-marine saline water in the southern part of the valley (e.g., high SO4, high Na/Cl, δ11B = 24 to 30 per mille, 87Sr/86Sr = 0.70852). The geochemical and isotopic fingerprints of the different water sources enables us to delineate the impact of these sources in different areas of the valley as well as to evaluate the origin of the saline, Sod-enriched plume, that is located north of Salinas City Our data

  9. Effect of faulting on ground-water movement in the Death Valley region, Nevada and California

    International Nuclear Information System (INIS)

    This study characterizes the hydrogeologic system of the Death Valley region, an area covering approximately 100,000 square kilometers. The study also characterizes the effects of faults on ground-water movement in the Death Valley region by synthesizing crustal stress, fracture mechanics,a nd structural geologic data. The geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. Faulting and associated fracturing is pervasive and greatly affects ground-water flow patterns. Faults may become preferred conduits or barriers to flow depending on whether they are in relative tension, compression, or shear and other factors such as the degree of dislocations of geologic units caused by faulting, the rock types involved, the fault zone materials, and the depth below the surface. The current crustal stress field was combined with fault orientations to predict potential effects of faults on the regional ground-water flow regime. Numerous examples of fault-controlled ground-water flow exist within the study area. Hydrologic data provided an independent method for checking some of the assumptions concerning preferential flow paths. 97 refs., 20 figs., 5 tabs

  10. Holocene glaciation of the central Sierra Nevada, California

    Science.gov (United States)

    Bowerman, Nicole D.; Clark, Douglas H.

    2011-05-01

    Sediment cores from two bedrock-dammed lakes in North Fork Big Pine Creek, Sierra Nevada, California, preserve the most detailed and complete record of Holocene glaciation yet recovered in the region. The lakes are fed by outwash from the Palisade Glacier, the largest (˜1.3 km 2) and presumably longest-lived glacier in the range, and capture essentially all of the rock flour it produces. Distinct late-Holocene (Matthes) and late-Pleistocene (Recess Peak) moraines lie between the modern glacier and the lakes. The lakes have therefore received continuous sedimentation from the basin since the retreat of the Tioga glacier (Last Glacial Maximum) and capture rock flour related to all post-LGM advances. A total of eight long cores (up to 5.5 m sediment depth) and one short surface sediment short core preserve a coherent record of fluctuating rock flour flux to the lakes through the Holocene. Age constraints on rock flour spikes in First and Second lakes based on 31 14C-dated macrofossils indicate Holocene glaciation began ˜3200 cal yr B P, followed by a possible glacier maximum at ˜2800 cal yr B P and four distinct glacier maxima at ˜2200, ˜1600, ˜700 and ˜250-170 cal yr. B.P., the most recent maximum being the largest. Reconstruction of the equilibrium-line altitudes (ELA) associated with each distinct advance recorded in the moraines (Recess Peak, Matthes, and modern) indicates ELA depressions (relative to modern) of ˜250 m and 90 m for Recess Peak and Matthes advances, respectively. These differences represent decreases in summer temperatures of 1.7-2.8 °C (Recess Peak) and 0.2-2° (Matthes), and increases in winter precipitation of 22-34 cm snow water equivalent (s.w.e.) (Recess Peak) and 3-26 cm s.w.e. (Matthes) compared to modern conditions. Although small, these changes are significant and similar to those noted in the Cascade Range to the north, and represent a significant departure from historical climate trends in the region.

  11. Estimated Thickness of Quaternary Sediment in the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated thickness of Quaternary sediment of the Wood River Valley aquifer system. This isopach map was constructed by subtracting the...

  12. Meteorology-induced variations in the spatial behavior of summer ozone pollution in Central California

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ling; Harley, Robert A.; Brown, Nancy J.

    2010-06-23

    Cluster analysis was applied to daily 8 h ozone maxima modeled for a summer season to characterize meteorology-induced variations in the spatial distribution of ozone. Principal component analysis is employed to form a reduced dimension set to describe and interpret ozone spatial patterns. The first three principal components (PCs) capture {approx}85% of total variance, with PC1 describing a general spatial trend, and PC2 and PC3 each describing a spatial contrast. Six clusters were identified for California's San Joaquin Valley (SJV) with two low, three moderate, and one high-ozone cluster. The moderate ozone clusters are distinguished by elevated ozone levels in different parts of the valley: northern, western, and eastern, respectively. The SJV ozone clusters have stronger coupling with the San Francisco Bay area (SFB) than with the Sacramento Valley (SV). Variations in ozone spatial distributions induced by anthropogenic emission changes are small relative to the overall variations in ozone amomalies observed for the whole summer. Ozone regimes identified here are mostly determined by the direct and indirect meteorological effects. Existing measurement sites are sufficiently representative to capture ozone spatial patterns in the SFB and SV, but the western side of the SJV is under-sampled.

  13. Aquifer Boundary of the Wood River Valley Aquifer System, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains the boundary of the Wood River Valley aquifer system as modified and expanded from that defined by Skinner and others (2007): It has been...

  14. A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

    Science.gov (United States)

    Foxgrover, Amy C.; Barnard, Patrick L.

    2012-01-01

    A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

  15. Investigation of ecosystems impacts from geothermal development in Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Shinn, J.H.; Ireland, R.R.; Kercher, J.R.; Koranda, J.J.; Tompkins, G.A.

    1979-07-13

    A summary of three years of field ecological investigation in Imperial Valley Environmental Program is presented. The potential terrestrial habitat impacts of geothermal development are discussed for shorebirds and waterfowl habitat, the endangered clapper rail, powerline corridors, noise effects, animal trace element burdens, and the desert community. Aquatic habitats are discussed in terms of Salton Sea salinity, effects of geothermal brine discharges to the Salton Sea, trace element baselines, and potential toxicity of brine spills in freshwater. Studies of impacts on agriculture involved brine movement in soil, release of trace metals, trace element baselines in soil and plants, water requirements of crops, and H{sub 2}S effects on crop production in the presence of CO{sub 2} and ozone.

  16. A brief history of oil and gas exploration in the southern San Joaquin Valley of California: Chapter 3 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    Science.gov (United States)

    Takahashi, Kenneth I.; Gautier, Donald L.

    2007-01-01

    The Golden State got its nickname from the Sierra Nevada gold that lured so many miners and settlers to the West, but California has earned much more wealth from so-called “black gold” than from metallic gold. The San Joaquin Valley has been the principal source for most of the petroleum produced in the State during the past 145 years. In attempting to assess future additions to petroleum reserves in a mature province such as the San Joaquin Basin, it helps to be mindful of the history of resource development. In this chapter we present a brief overview of the long and colorful history of petroleum exploration and development in the San Joaquin Valley. This chapter relies heavily upon the work of William Rintoul, who wrote extensively on the history of oil and gas exploration in California and especially in the San Joaquin Valley. No report on the history of oil and gas exploration in the San Joaquin Valley would be possible without heavily referencing his publications. We also made use of publications by Susan Hodgson and a U.S. Geological Survey Web site, Natural Oil and Gas Seeps in California (http://seeps.wr.usgs.gov/seeps/index.html), for much of the material describing the use of petroleum by Native Americans in the San Joaquin Valley. Finally, we wish to acknowledge the contribution of Don Arnot, who manages the photograph collection at the West Kern Oil Museum in Taft, California. The collection consists of more than 10,000 photographs that have been scanned and preserved in digital form on CD-ROM. Many of the historical photographs used in this paper are from that collection. Finally, to clarify our terminology, we use the term “San Joaquin Valley” when we refer to the geographical or topographical feature and the term “San Joaquin Basin” when we refer to geological province and the rocks therein.

  17. 76 FR 298 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2011-01-04

    ... Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation......... 12/17/92 08/24/07 On September 17, 2007, the submittal for San Joaquin Valley Unified Air Pollution... December 13, 1994 (59 FR 64132), EPA approved into the SIP a previous version of Rule 4402, SJVUAPCD...

  18. Breschini and Haversat, eds.: Papers on Central California Prehistory

    OpenAIRE

    Elsasser, A B

    1985-01-01

    Papers on Central California Prehistory: 1. Gary S. Breschini and Trudy Haversat, series editors. Salinas, CA. Coyote Press Archives of California Prehistory, No. 3, 1984. 87 pp., figures, tables, photos, $4.95, (paper).

  19. Surface Displacement of the 17 May 1993 Eureka Valley, California, Earthquake Observed by SAR Interferometry.

    Science.gov (United States)

    Peltzer, G; Rosen, P

    1995-06-01

    Satellite synthetic aperture radar (SAR) interferometry shows that the magnitude 6.1 Eureka Valley earthquake of 17 May 1993 produced an elongated subsidence basin oriented north-northwest, parallel to the trend defined by the aftershock distribution, whereas the source mechanism of the earthquake implies a north-northeast-striking normal fault. The +/-3-millimeter accuracy of the radar-observed displacement map over short spatial scales allowed identification of the main surface rupture associated with the event. These observations suggest that the rupture began at depth and propagated diagonally upward and southward on a west-dipping, north-northeast fault plane, reactivating the largest escarpment in the Saline Range. PMID:17778980

  20. 76 FR 38572 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2011-07-01

    ...'' subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October... taking direct final action to approve revisions to the Antelope Valley Air Quality Management District... Valley Air Quality Management District (AVAQMD) and submitted by the California Air Resources Board...

  1. Preliminary Image Map of the 2007 Buckweed Fire Perimeter, Green Valley Quadrangle, Los Angeles County, California

    Science.gov (United States)

    Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

    2008-01-01

    In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

  2. Preliminary Image Map of the 2007 Buckweed Fire Perimeter, Sleepy Valley Quadrangle, Los Angeles County, California

    Science.gov (United States)

    Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

    2008-01-01

    In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

  3. Preliminary Image Map of the 2007 Witch Fire Perimeter, Valley Center Quadrangle, San Diego County, California

    Science.gov (United States)

    Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

    2008-01-01

    In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

  4. Coping with naturally-high levels of soil salinity and boron in the westside of central California

    OpenAIRE

    Gary S. Bañuelos

    2015-01-01

    California has one of the most productive agricultural regions of the world, producing more than 400 commodities with a value of more than $37 billion. In the westside of central California, over 200,000 ha exhibit naturally high levels of salinity and boron (B) in the soils, especially those derived from Cretaceous soils. Both excessive salt and B negatively impact agronomic production in this part of California, which has severe economic consequences for the farming communities. Developing ...

  5. Boundary of the Death Valley region by Bedinger and others (1989), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set delineates the boundary of the Death Valley region that was first evaluated by the U.S. Geological Survey (USGS) as a potential hydrogeologic...

  6. Paleoseismologic evidence for late Holocene earthquakes on the Southern Panamint Valley fault zone: Implications for earthquake clustering in the Eastern California Shear Zone north of the Garlock fault

    Science.gov (United States)

    McAuliffe, L. J.; Dolan, J. F.; Kirby, E.; Haravitch, B.; Alm, S.

    2010-12-01

    New paleoseismological data from two trenches excavated across the southern end of the Panamint Valley fault (PVF), the most active of the three major faults in the eastern California shear zone (ECSZ) north of the Garlock fault, reveal the occurrence of at least two, and probably three, surface ruptures during the late Holocene. These trenches were designed to test the hypothesis that the earthquake clusters and intervening seismic lulls observed in the Mojave section of the ECSZ (Rockwell et al. 2000, Ganev et al. 2010) at 8-9.5 ka, 5-6 ka and during the past ~1-1.5 ka, also involved the fault systems of the ECSZ north of the Garlock fault. Well stratified playa sands, silts and clays exposed in the trench allowed precise identification of two event horizons; a likely third event horizon occurred during a period of soil development across the playa. Calibrated radiocarbon dates from 25 charcoal samples constrain the dates of the most recent event (MRE) to ~1450-1500 AD and the ante-penultimate event at 3.2-3.6 ka. The penultimate event occurred during a period of soil development spanning ~350-1400 AD. The presence of large blocks of soil in what appears to be scarp-derived colluvium in a large fissure opened during this event require that it occurred late during soil development, probably only a few hundred years before the MRE. The timing of the three events indicate that the southern PVF has ruptured at least once, and probably twice during the ongoing seismic cluster in the Mojave region. The PVF earthquakes also are similar in age to the 1872 Owens Valley earthquakes and the geomorphically youthful, but undated MRE in central Death Valley. Although we were unable to excavate deeply enough at this site to expose mid-to lower - Holocene playa strata, the timing of the ante-penultimate earthquake at our site shows that the PVF has ruptured at least once during the well-defined 2-5 ka seismic lull in the Mojave section of the ECSZ. Interestingly the 3.2-3.6 ka

  7. Eruptive History and Chemical Evolution of the Precaldera and Postcaldera Basalt-Dacite Sequences, Long Valley, California: Implications for Magma Sources, Current Seismic Unrest, and Future Volcanism

    Science.gov (United States)

    Bailey, Roy A.

    2004-01-01

    The Long Valley Volcanic Field in east-central California straddles the East Sierran frontal fault zone, overlapping the Sierra Nevada and western Basin and Range Provinces. The volcanic field overlies a mature mid-Tertiary erosional surface that truncates a basement composed mainly of Mesozoic plutons and associated roof pendants of Mesozoic metavolcanic and Paleozoic metasedimentary rocks. Long Valley volcanism began about 4 Ma during Pliocene time and has continued intermittently through the Holocene. The volcanism is separable into two basalt-rhyolite episodes: (1) an earlier, precaldera episode related to Long Valley Caldera that climaxed with eruption of the Bishop Tuff and collapse of the caldera; and (2) a later, postcaldera episode structurally related to the north-south-trending Mono-Inyo Craters fissure system, which extends from the vicinity of Mammoth Mountain northward through the west moat of the caldera to Mono Lake. Eruption of the basalt-dacite sequence of the precaldera basalt-rhyolite episode peaked volumetrically between 3.8 and 2.5 Ma; few basalts were erupted during the following 1.8 m.y. (2.5?0.7 Ma). Volcanism during this interval was dominated by eruption of the voluminous rhyolites of Glass Mountain (2.2?0.8 Ma) and formation of the Bishop Tuff magma chamber. Catastrophic rupture of the roof of this magma chamber caused eruption of the Bishop Tuff and collapse of Long Valley Caldera (760 ka), after which rhyolite eruptions resumed on the subsided caldera floor. The earliest postcaldera rhyolite flows (700?500 ka) contain quenched globular basalt enclaves (mafic magmatic inclusions), indicating that basaltic magma had reentered shallow parts of the magmatic system after a 1.8-m.y. hiatus. Later, at about 400 ka, copious basalts, as well as dacites, began erupting from vents mainly in the west moat of the caldera. These later eruptions initiated the postcaldera basalt-rhyolite episode related to the Mono-Inyo Craters fissure system, which

  8. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

    2014-11-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations

  9. Coastal, valley, and oasis interaction: impact on the evolution of ancient populations in the South Central Andes.

    Science.gov (United States)

    Varela, Héctor H; Cocilovo, Jose A; Fuchs, María L; O'Brien, Tyler G

    2014-12-01

    The existing biocultural links are analyzed among ancient inhabitants of the Cochabamba valleys (Bolivia) from the Formative and Tiwanaku periods, coastal and inland Azapa region (Chile) from the Late Archaic to the Late periods, and the Atacama Desert oases (Chile) from the Formative period to the time of European contact. Craniometric information obtained from a sample of 565 individuals from different sites of the studied regions was evaluated using methods derived from quantitative genetics and multivariate statistical analysis techniques. It is shown that during the Formative and Tiwanaku periods inhabitants of the Cochabamba valleys maintained contact with the population of northern Chile. This contact was more fluid with the people from the interior valley of Azapa than it was with the settlers of San Pedro Atacama (SPA). An important biological affinity in the Late Period between the inhabitants of the Azapa valley and the late SPA groups is also examined. The Late-Inca Catarpe SPA sample shows a broad genetic variability shared with the majority of the groups studied. The results reaffirm the differences between the coastal and interior Azapa valley groups and strengthen the hypothesis of two pathways to populating the south central Andean area. The divergence observed among subpopulations can be explained by the spatiotemporal dispersion between them, genetic drift dispersion compensated by the action of gene flow, and cultural norms that regulate within group mating. PMID:25234247

  10. Analytical modeling of gravity changes and crustal deformation at volcanoes: The Long Valley caldera, California, case study

    Science.gov (United States)

    Battaglia, Maurizio; Hill, D.P.

    2009-01-01

    Joint measurements of ground deformation and micro-gravity changes are an indispensable component for any volcano monitoring strategy. A number of analytical mathematical models are available in the literature that can be used to fit geodetic data and infer source location, depth and density. Bootstrap statistical methods allow estimations of the range of the inferred parameters. Although analytical models often assume that the crust is elastic, homogenous and isotropic, they can take into account different source geometries, the influence of topography, and gravity background noise. The careful use of analytical models, together with high quality data sets, can produce valuable insights into the nature of the deformation/gravity source. Here we present a review of various modeling methods, and use the historical unrest at Long Valley caldera (California) from 1982 to 1999 to illustrate the practical application of analytical modeling and bootstrap to constrain the source of unrest. A key question is whether the unrest at Long Valley since the late 1970s can be explained without calling upon an intrusion of magma. The answer, apparently, is no. Our modeling indicates that the inflation source is a slightly tilted prolate ellipsoid (dip angle between 91?? and 105??) at a depth of 6.5 to 7.9??km beneath the caldera resurgent dome with an aspect ratio between 0.44 and 0.60, a volume change from 0.161 to 0.173??km3 and a density of 1241 to 2093??kg/m3. The larger uncertainty of the density estimate reflects the higher noise of gravity measurements. These results are consistent with the intrusion of silicic magma with a significant amount of volatiles beneath the caldera resurgent dome. ?? 2008 Elsevier B.V.

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

    Science.gov (United States)

    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

  12. Chemical quality of ground water in the Tehama-Colusa Canal service area, Sacramento Valley, California

    Science.gov (United States)

    Bertoldi, Gilbert L.

    1976-01-01

    The Tehama-Colusa Canal Service Area consists of about 450 square miles of irrigable land located on the west side of the Sacramento Valley, Calif. Upon the completion of the Tehama-Colusa Canal, it is expected that most of the service area will switch from passive forms of agriculture (dry farming and grazing) to intensive irrigated farming. Importation and application of surface water may affect the chemical quality of native ground water. This study documents the chemical quality of native ground water before large-scale importation and application of surface water provide the potential of altering the ground-water chemistry. Analyses of samples from 222 wells show that most of the area is underlain by ground water of a quality suitable for most agricultural and domestic uses. In the vicinities of College City-Arbuckle and the city of Williams, boron, chloride, sodium, and dissolved solids may be a threat to future agricultural activities where boron- or chloride-sensitive crops would be grown. The source of degraded ground water in the two areas is local intermittent streams that drain areas having numerous saline springs and seeps. (Woodard-USGS)

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    D. Jiménez

    2014-11-01

    Full Text Available 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.

  15. Isotope and Genetic Analyses of a Mass Grave in Central California

    DEFF Research Database (Denmark)

    Eerkens, Jelmer; Carlson, Traci; Malhi, Ripan S.;

    2016-01-01

    ABSTRACT Objectives Analysis of a mass burial of seven males at CA-ALA-554, a prehistoric site in the Amador Valley, CA, was undertaken to determine if the individuals were “locals” or “non-locals,” and how they were genetically related to one another. Methods The study includes osteological......, genetic (mtDNA), and stable (C, N, O, S) and radiogenic (Sr) isotope analyses of bone and tooth (first and third molars) samples. Results Isotopes in first molars, third molars, and bone show they spent the majority of their lives living together. They are not locals to the Amador Valley, but were...... intergroup warfare accounts for the mass burial. Genetic data suggest the raiding party included sets of unrelated men, perhaps from different households. Generalizing from this case and others like it, we hypothesize that competition over territory was a major factor behind ancient warfare in Central...

  16. Analysis of projected water availability with current basin management plan, Pajaro Valley, California

    Science.gov (United States)

    Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang

    2014-01-01

    The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within “water-balance subregions” (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori.

  17. Residential Agricultural Pesticide Exposures and Risk of Neural Tube Defects and Orofacial Clefts Among Offspring in the San Joaquin Valley of California

    OpenAIRE

    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 i...

  18. Dynamic modeling of organophosphate pesticide load in surface water in the northern San Joaquin Valley watershed of California

    Energy Technology Data Exchange (ETDEWEB)

    Luo Yuzhou [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou, 325000 (China); Zhang Xuyang [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Liu Xingmei [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Soil, Water and Environmental Science, Zhejiang University, Hangzhou 310029 (China); Ficklin, Darren [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Zhang Minghua [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou, 325000 (China)], E-mail: mhzhang@ucdavis.edu

    2008-12-15

    The hydrology, sediment, and pesticide transport components of the Soil and Water Assessment Tool (SWAT) were evaluated on the northern San Joaquin Valley watershed of California. The Nash-Sutcliffe coefficients for monthly stream flow and sediment load ranged from 0.49 to 0.99 over the watershed during the study period of 1992-2005. The calibrated SWAT model was applied to simulate fate and transport processes of two organophosphate pesticides of diazinon and chlorpyrifos at watershed scale. The model generated satisfactory predictions of dissolved pesticide loads relative to the monitoring data. The model also showed great success in capturing spatial patterns of dissolved diazinon and chlorpyrifos loads according to the soil properties and landscape morphology over the large agricultural watershed. This study indicated that curve number was the major factor influencing the hydrology while pesticide fate and transport were mainly affected by surface runoff and pesticide application and in the study area. - Major factors governing the instream loads of organophosphate pesticides are magnitude and timing of surface runoff and pesticide application.

  19. Ecology of Waterfowl and Their Habitats During Spring Migration in Southern Oregon-Northeastern California (SONEC)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Miller et al. (2005) defined the SONEC region using locations of the 77–87% of the female northern pintails (Anas acuta) from the Central Valley of California...

  20. Nature of uranium contamination in the agricultural drainage water evaporation ponds of the San Joaquin Valley, California, USA

    International Nuclear Information System (INIS)

    Evaporation ponds used for agricultural subsurface drainage water disposal in the Tulare Lake Bed (TLB) of the San Joaquin Valley, California, USA have elevated levels of U. Waterfowl which inhabit and forage the ponds and surrounding areas are threatened by exposure to U. The ponds, which receive irrigation drainage waters and seasonal rain, are subject to wetting and drying periods. The periods result in the accumulation of decaying algae and other organic material in surface sediments. Sediment and waters in the ponds were sampled to determine what factors control U solubility and sediment U concentrations. Data from a 1990 study conducted by Chilcott et al. in 1989 on the TLB ponds were used to help identify what factors may control U solubility. Pond sediment U concentrations decreased abruptly with depth and surface sediment U concentrations were related to dissolved Ca:HCO3 ratios. Pond algal U bioaccumulation was favored in waters with high Ca:HCO3 ratios, which had lower pH values and carbonate alkalinities than waters with low CA:HCO3 ratios. Ponds with high salinities and high carbonate alkalinities contained the highest aqueous U concentrations relative to other TLB ponds. Sediment total organic carbon (TOC) was correlated with sediment U concentrations, suggesting that U is bound to organic matter. The source of TOC is most likely from algae deposition. (author)

  1. Foraging patterns of acorn woodpeckers (Melanerpes formicivorus) on valley oak (Quercus lobata Née) in two California oak savanna-woodlands

    OpenAIRE

    Scofield, Douglas G.; Alfaro, Victor Ryan; Victoria L. Sork; Grivet, Delphine; Martinez, Edith; Papp, Jeannette; Andrea R Pluess; Koenig, Walter D.; Smouse, Peter E.

    2010-01-01

    Landscape characteristics and social behavior can affect the foraging patterns of seed-dependent animals. We examine the movement of acorns from valley oak (Quercus lobata) trees to granaries maintained by acorn woodpeckers (Melanerpes formicivorus) in two California oak savanna-woodlands differing in the distribution of Q. lobata within each site. In 2004, we sampled Q. lobata acorns from 16 granaries at Sedgwick Reserve in Santa Barbara County and 18 granaries at Hastings Reserve in Montere...

  2. Coping with naturally-high levels of soil salinity and boron in the westside of central California

    Directory of Open Access Journals (Sweden)

    Gary S. Bañuelos

    2015-02-01

    Full Text Available California has one of the most productive agricultural regions of the world, producing more than 400 commodities with a value of more than $37 billion. In the westside of central California, over 200,000 ha exhibit naturally high levels of salinity and boron (B in the soils, especially those derived from Cretaceous soils. Both excessive salt and B negatively impact agronomic production in this part of California, which has severe economic consequences for the farming communities. Developing new salt and B management methods and identifying alternative tolerant crops are essential agronomic strategies for this region of California.

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

    OpenAIRE

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

    2013-01-01

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

  4. Hydrodynamic and isotopic characterization of a site contaminated by chlorinated solvents: Chienti River Valley, Central Italy

    International Nuclear Information System (INIS)

    Highlights: ► The fate of chlorinated solvents in groundwater in an alluvial aquifer has been investigated. ► Heterogeneity of the aquifer sediments causes vertical components of groundwater flow. ► Multilevel data shows the VOC’s stratification in the aquifer. ► Concentration and δ13C and δ37Cl data showed that dilution controls the VOC’s distribution. ► Biodegradation has been confirmed by isotope data only in low permeability layers. - Abstract: Contaminant sources have been attributed to shoe manufacturers in an alluvial aquifer located along 26 km2 in the Chienti River Valley, Central Italy. During the 1980s and 1990s, the main chlorinated compound used in the study area was 1,1,1-Trichloroethane (1,1,1-TCA), which was substituted by Perchloroethene (PCE) in the last 15 years. A hydrogeological conceptual model has been developed for the alluvial aquifer taking into account the presence of low permeability lenses, forming a multilayer semi-confined aquifer. Hydrodynamic tests (pumping and flowmeter heat-pulse tests) coupled with standard and multilevel hydrochemical and isotopic samplings were performed. Flowmeter tests showed the existence of vertical flow between aquifer levels having different permeability. Physical–chemical parameter logs agreed with the existence of a multilayer aquifer. Concentration data collected in 21 wells located downgradient of the different sources revealed VOC (Volatile Organic Compound) levels lower than 100 μg/L in the upper part of the valley and levels reaching about 200 μg/L in the near shore areas. PCE is the main compound present in the aquifer. No evidence of the presence of TCA was found in the upper areas of the Chienti Valley, but in the areas near the shore, TCA and its degradation products are predominant. Data collected at multilevels located at two sites (upper and near shore areas) to refine the results obtained in the regional survey show a stratification of the VOC concentrations; values of

  5. Metallurgical traditions under Inka rule: a technological study of metals and technical ceramics from the Aconcagua Valley, Central Chile

    OpenAIRE

    Plaza, M.T.; Martinón-Torres, M.

    2015-01-01

    The spread of the Inka state in the Aconcagua Valley (Central Chile) is thought to have been culturally mediated, avoiding military coercion, and thus leading to different forms of cultural acceptance, resistance or hybridisation. However, there has been no previous attempt to investigate the extent to which these interactions are reflected in the use of metals and metallurgical technologies. Here we present analytical work on metallic artefacts and technical ceramics from Cerro La Cruz and L...

  6. Evaluation of increases in dissolved solids in ground water, Stovepipe Wells Hotel, Death Valley National Monument, California

    Science.gov (United States)

    Buono, Anthony; Packard, E.M.

    1982-01-01

    Increases in dissolved solids have been monitored in two observation wells near Stovepipe Wells Hotel, Death Valley National Monument, California. One of the hotel 's supply wells delivers water to a reverse-osmosis treatment plant that produces the area 's potable water supply. Should water with increased dissolved solids reach the supply well, the costs of production of potable water will increase. The reverse-osmosis plant supply well is located about 0.4 mile south of one of the wells where increases have been monitored, and 0.8 mile southwest of the well where the most significant increases have been monitored. The direction of local ground-water movement is eastward, which reduces the probability of the supply well being affected. Honey mesquite, a phreatophyte located about 1.5 miles downgradient from the well where the most significant increases have been monitored, might be adversely affected should water with increased dissolved solids extend that far. Available data and data collected during this investigation do not indicate the source of the dissolved-solids increases. Continued ground-water-quality monitoring of existing wells and the installation of additional wells for water-quality monitoring would be necessary before the area affected by the increases, and the source and direction of movement of the water with increased dissolved solids, can be determined. (USGS)

  7. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for rare/sensitive species occurrences of terrestrial mammals in Central California. Vector polygons in...

  8. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats of Central California classified according to the Environmental...

  9. Delineation and hydrologic effects of a gasoline leak at Stovepipe Wells Hotel, Death Valley National Monument, California

    Science.gov (United States)

    Buono, A.; Packard, Elaine M.

    1982-01-01

    Ground water is the only local source of water available to the Stovepipe Wells Hotel facilities of the Death Valley National Monument, California. A leak in a service station storage tank caused the formation of a gasoline layer overlying the water table, creating the potential for contamination of the water supply. The maximum horizontal extent of the gasoline layer was mathematically estimated to be 1,300 feet downgradient from the leaky gasoline tank. Exploratory drilling detected the gasoline layer between 900 and 1,400 feet downgradient and between 50 and 150 feet upgradient from the source. Traces of the soluble components of gasoline were also found in the aquifer 150 feet upgradient, and 250 feet distant from the source perpendicular to the direction of ground-water movement. The gasoline spill is not likely to have an effect on the supply wells located 0.4 mile south of the leak source, which is nearly perpendicular to the direction of ground-water movement and the primary direction of gasoline movement in the area. No effect on phreatophytes 2 miles downgradient from the layer is likely, but the potential effects of gasoline vapors within the unsaturated zone on local xerophytes are not known. (USGS)

  10. Carbon Cycling Studies in Forest and Rangeland Ecosystems of Northern and Central Coastal California

    Science.gov (United States)

    Potter, C.; Klooster, S.; Gross, P.; Hiatt, S.; Genovese, V.

    2008-12-01

    The varied topography and micro-climates of northern and central coastal California result in high biodiversity and many different levels of primary production driving regional carbon cycles. Coastal mountains trap moisture from low clouds and fog in summer to supplement rainfall in winter. This creates a favorable micro-environment for coniferous forests, including the southernmost habitat of the coast redwood (Sequoia sempervirens), which grows mainly on lower north-facing slopes in Big Sur. In rain shadows, forests transition to open oak woodland, and then into the more fire-tolerant chaparral and coast scrub. Field sites for our on-going climate change studies on the California northern and central coasts currently include the University of California Santa Cruz Campus Natural Reserve, the US Forest Service Brazil Ranch, and the University of California Big Creek Reserve. We are conducting research at each of these sites to better understand possible impacts of climate change, including: (1) biological and physical capacity of soils to capture carbon and retain plant-essential nutrients; (2) rates of plant-soil water and carbon cycling and energy flow; and (3) recovery mechanisms for disturbances such as invasive weed species, grazing, and wildfire. The NASA-CASA simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate carbon cycling for much of the central coast as far north as Mendocino County. Net primary production (NPP) of all vegetation cover was mapped at 30-meter resolution for selected years by combining MODIS and Landsat images across the region. Results show annual NPP predictions of between 200-400 grams C per square meter for coastal scrub and 800-1200 grams C per square meter for coastal evergreen forests, Net ecosystem fluxes of carbon will be presented for the region based on NASA-CASA modeling and field measurements of soil respiration fluxes.

  11. Stable isotopic composition of groundwater of central California as an indicator of mid-pleistocene tectonic evolution

    International Nuclear Information System (INIS)

    In the western and central San Joaquin Valley, California, present-day shallow groundwaters with δ18O=-7.4 and -11.5 per mille, respectively, comprised of modern recharge are separated from an underlying, lower salinity, confined-aquifer system (δ18O=-9 per mille) by the thick, low permeability Corcoran Clay. The substantial thickness of the lacustrine Corcoran Clay, together with small differential head and low structural relief during much of Pleistocene time, have combined to prevent flushing of the confined paleowaters. This unusual hydrologic system of isotopically light water with a mean δ18O of -11 per mille overlying lower salinity, isotopically heavy water supports a tectonic model that calls for uplift of the Central Coast Ranges by about 1100 m in the past 615,000 a. Before uplift, water from the Sierra Nevada with a δ18O value of about -10 per mille mixed in intermittent lakes with water from the pre-emergent Coast Ranges with a δ18O value of about -6 per mille, resulting in blends of recharge water of about -9 per mille in the principal confined aquifer. Chemical and isotopic mass-balance calculations suggest that the western contribution to the confined waters ranged from 20% in the north to 35% in the southern part of the aquifer system. The present 1400 m height of the Coast Ranges results in a higher cloud base and greater interception of precipitation from storms moving inland from the Pacific than had occurred in mid-Pleistocene times. As a consequence, modern precipitation is more depleted in D and 18O over the eastern border of the central Coast Ranges and the Sierra Nevada than was pre-Corcoran precipitation. (author). 22 refs, 5 figs, 3 tabs

  12. Trap catches of the sweetpotato whitefly (Homoptera: Aleyrodidae) in the Imperial Valley, California, from 1996 to 2002

    Institute of Scientific and Technical Information of China (English)

    CHANG-CHI CHU; EDWARD BARNES; ERIC T. NATWICK; TIAN-YE CHEN; DAVID RITTER; THOMAS J. HENNEBERRY

    2007-01-01

    An outbreak of the sweetpotato whitefly, Bemisia tabaci (Gennadius), biotype B occurred in the Imperial Valley, California in 1991. The insects destroyed melon crops and seriously damaged other vegetables, ornamentals and row crops. As a result of the need for sampling technology, we developed a whitefly trap (named the CC trap) that could be left in the field for extended time periods. We used the traps to monitor populations of B. tabaci adults during year-round samplings from 1996 to 2002 to study variations in the weekly trap catches of the insect. The greatest number of B. tabaci adults was recorded in 1996, followed by a continuing annual decrease in trap catches each year through 2002. The overall decline of B. tabaci is attributed in part to the adoption of an integrated pest management (IPM) program initiated in 1992 and reduced melon hectares from 1996 to 2002. Other factors may also have contributed to the population reductions. Seasonally, B. tabaci trap catches decreased during the late summer and fall concurrent with decreasing minimum temperatures that are suggested to be a significant factor affecting seasonal activity and reproduction.

  13. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for dolphins, porpoises, whales, seals, sea lions, and sea otters in Central California. Vector polygons...

  14. 77 FR 2496 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-01-18

    ... Valley Air Quality Management District (AVAQMD) and Imperial County Air Pollution Control District... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial Valley Air Pollution Control District AGENCY: Environmental...

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

    Science.gov (United States)

    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.

  16. Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California

    Science.gov (United States)

    Ji, Kang Hyeun; Herring, Thomas A.; Llenos, Andrea L.

    2013-03-01

    Long Valley Caldera in eastern California is an active volcanic area and has shown continued unrest in the last three decades. We have monitored surface deformation from Global Positioning System (GPS) data by using a projection method that we call Targeted Projection Operator (TPO). TPO projects residual time series with secular rates and periodic terms removed onto a predefined spatial pattern. We used the 2009-2010 slow deflation as a target spatial pattern. The resulting TPO time series shows a detailed deformation history including the 2007-2009 inflation, the 2009-2010 deflation, and a recent inflation that started in late-2011 and is continuing at the present time (November 2012). The recent inflation event is about four times faster than the previous 2007-2009 event. A Mogi source of the recent event is located beneath the resurgent dome at about 6.6 km depth at a rate of 0.009 km3/yr volume change. TPO is simple and fast and can provide a near real-time continuous monitoring tool without directly looking at all the data from many GPS sites in this potentially eruptive volcanic system.

  17. Food limitation of sea lion pups and the decline of forage off central and southern California.

    Science.gov (United States)

    McClatchie, Sam; Field, John; Thompson, Andrew R; Gerrodette, Tim; Lowry, Mark; Fiedler, Paul C; Watson, William; Nieto, Karen M; Vetter, Russell D

    2016-03-01

    California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish and market squid forage. In the last decade off central California, where breeding female sea lions from San Miguel rookery feed, sardine and anchovy greatly decreased in biomass, whereas market squid and rockfish abundance increased. Pup weights fell as forage food quality declined associated with changes in the relative abundances of forage species. A model explained 67% of the variance in pup weights using forage from central and southern California and 81% of the variance in pup weights using forage from the female sea lion foraging range. A shift from high to poor quality forage for breeding females results in food limitation of the pups, ultimately flooding animal rescue centres with starving sea lion pups. Our study is unusual in using a long-term, fishery-independent dataset to directly address an important consequence of forage decline on the productivity of a large marine predator. Whether forage declines are environmentally driven, are due to a combination of environmental drivers and fishing removals, or are due to density-dependent interactions between forage and sea lions is uncertain. However, declining forage abundance and quality was coherent over a large area (32.5-38° N) for a decade, suggesting that trends in forage are environmentally driven. PMID:27069651

  18. Maize Response to Fertilizer Dosing at Three Sites in the Central Rift Valley of Ethiopia

    Directory of Open Access Journals (Sweden)

    Getachew Sime

    2014-09-01

    Full Text Available This study examines the agronomic response, efficiency and profitability of fertilizer microdosing in maize. An experiment with the following treatments was conducted: control without fertilizer, microdosing treatments, with the rate of 27 + 27, 53 + 53 and 80 + 80 kg ha−1, and banding of fertilizer with 100 + 100 kg ha−1 of di ammonium phosphate (DAP + urea, applied at planting and jointing, respectively. The treatments were arranged in a randomized complete block design with four replications. The experiment was conducted during the 2011/2012 and 2012/2013 cropping seasons at Ziway, Melkassa and Hawassa in the semiarid central rift valley region of Ethiopia. Compared to the control, the fertilizer treatments had higher yield and fertilizer use efficiency (FUE profitably. The 27 + 27 kg ha−1 fertilizer rate increased the grain yield by 19, 45 and 46% at Hawassa, Ziway and Melkassa, respectively, and it was equivalent to the higher rates. The value cost ratio (VCR was highest with the lowest fertilizer rate, varying between seven and 11 in the treatment with 27 + 27 kg ha−1, but two and three in the banding treatment. Similarly, FUE was highest with the lowest fertilizer rate, varying between 23 and 34 kg kg−1 but 7 and 8 kg kg−1 in the banding treatment. The improved yield, FUE, VCR and gross margin in maize with microdosing at the 27 + 27 kg ha−1 of DAP + urea rate makes it low cost, low risk, high yielding and profitable. Therefore, application of this particular rate in maize may be an option for the marginal farmers in the region with similar socioeconomic and agroecological conditions.

  19. An Estimate of White Sharks off Central California

    OpenAIRE

    Chapple, Taylor

    2011-01-01

    Fewer white sharks (Carcharodon carcharias) inhabit the northeast Pacific Ocean than scientists previously thought. The first official count of the iconic marine predator is consistent with genetic studies that have shown a low degree of genetic variability among the animals.

  20. Investigation of the Transient Response of Gower Gulch to Forced Diversion, Death Valley, California

    Science.gov (United States)

    Schultz, L. L.; Snyder, N. P.

    2005-12-01

    We document sequential stages of the evolution of Gower Gulch in response to a forced diversion in 1941, using aerial photographs and field surveys. This artificial stream capture provides a rare opportunity to evaluate initial channel conditions and the ongoing response of the system. Five sets of aerial photographs (flight dates 1948, 1960, 1971, 1982, and 1995) have been orthorectified or registered for thorough geomorphic analysis. The response differs throughout the channel, depending on pre-diversion conditions and lithology. At the diversion point and the mouth, bedrock-floored knickzones have formed. Channel narrowing and incision characterize these steep reaches, with upstream knickpoint migration by pothole abrasion. In the central part of the channel, underlain by soft, fine-grained sedimentary rocks, the channel is covered in alluvium and has widened from an average of 14.8 m in 1948 to 24.6 m in 2005. Incision in this area is approximately 1-3 m, as indicated by tributary terraces. In the alluvial fan, the channel has incised up to 6.9 m, and widened from 10.9 m to 45.6 m. Above the diversion, Furnace Creek Wash has narrowed by approximately 12 meters since 1948.

  1. Boundary of the area contributing flow to the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundary of the area contributing ground-water flow to the Death Valley regional ground-water flow-system (DVRFS) model domain....

  2. Habitat Range of two Alpine Medicinal Plants in a Trans-Himalayan Dry Valley, Central Nepal

    Institute of Scientific and Technical Information of China (English)

    Bharat Babu SHRESTHA; Pramod Kumar JHA

    2009-01-01

    Understanding of the habitat range of threatened Himalayan medicinal plants which are declining in their abundance due to high anthropogenic disturbances is essential for developing conservation strategies and agro-technologies for cultivation. In this communication, we have discussed the habitat range of two alpine medicinal plants, Aconitum naviculare (Briihl) Stapf and Neopierorhiza scrophulariiflora (Pennel) Hong in a trans-Himalayan dry valley of central Nepal, Manang district. They are the most prioritized medicinal plants of the study area in terms of ethnomedicinal uses. A. naviculare occurs on warm and dry south facing slopes between 4090-4650 m asl along with sclerophyllous and thorny alpine scrubs, while N. serophulariiflora is exclusively found on cool and moist north facing slope between 4o0o and 4400 m asl where adequate water is available from snow melt to create a suitable habitat for this wetland dependent species. The soil in rooting zone of the two plants differs significantly in organic carbon (OC), organic matter (OM), total nitrogen (N) and carbon to nitrogen (C/N) ratio. Due to cool and moist condition of N. scrophulariiflora habitat, accumulation of soil OC is higher, but soil N content is lower probably due to slow release from litter, higher leaching loss and greater retention in perennial live biomass of the plant. The C/N ratio of soil is more suitable in A. navuculare habitat than that of N scrophulariiflora for N supply. Warm and sunny site with N rich soft can be suitable for cultivation of A. naviculare, while moist and cool site with organic soil for N. scrophulariiflora. The populations of both the plants are fragmented and small. Due to collection by human and trampling damage by livestock, the population of A. naviculare was found absent in open areas in five of the six sampling sites and it was confined only within the bushes of alpine scrubs. For N. serophulariiflora, high probability of complete receding of small glaciers may

  3. Late Cenozoic sedimentation in Pilot Knob Valley, California

    Science.gov (United States)

    Rittase, W. M.; Walker, J. D.; Kirby, E.; Andrew, J.; Wan, E.

    2012-12-01

    In Pilot Knob Valley (PKV), active inversion of a Pliocene-mid Pleistocene basin presents the opportunity to understand the spatial and temporal development of an enigmatic basin astride a major transform boundary in California. Here, a ~1000-m-thick package of exposed Late Cenozoic strata has been uplifted and tilted to the northeast. Based on new age and provenance data, we adopt the name Pilot Knob formation (PKfm) to describe much of these exposed rocks north of the Garlock fault (GF) and east of Christmas Canyon gate. Post-Miocene development of PKV is strongly influenced by the sinistral GF, the newly identified Marine Gate fault (MGF) and dextral Eastern California shear zone. The PKfm consists of three lithofacies members, from base to top: (1) rocks derived from Eagle Crags to the south; (2) Randsburg Wash lacustrine rocks; and (3) an upper member derived from the Slate Range. Tephrochronologic data from four PKfm ash samples brackets deposition of lacustrine Randsburg Wash Member rocks between 3.7-3.1 Ma and lacustrine rocks of the Slate Range Member between 1.2-0.6 Ma. A fifth tephrochronologic sample from lacustrine-distal alluvial sediments south of the GF near Christmas Canyon brackets deposition of a possible PKfm facies at ~3.1 Ma. A 3-stage tectonic model for northern PKV explains changing provenance patterns. Prior to ~3.1 Ma, the western PKV paleo-low lay north of the current GF adjacent to the southern Slate Range and connected to Searles Valley. The MGF cuts adjacent to the southern face of the Slate Range and southern Searles Valley with up to 7.5 km of sinistral oblique-normal slip between ~5-2.5 Ma. Eagle Crags fanglomerate deposition may continue after 3.7 Ma west of the Randsburg Wash-Searles Valley spillway, but these rocks have been eroded away. By ~3.7 Ma, northward progradation of Eagle Crags fanglomerate waned and lacustrine sediments were deposited north of the GF and east of the Randsburg Wash-Searles Valley spillway. At ~3.1 Ma

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  6. Ammonia and methane dairy emission plumes in the San Joaquin Valley of California from individual feedlot to regional scales

    Science.gov (United States)

    Miller, David J.; Sun, Kang; Tao, Lei; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo

    2015-09-01

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv-1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20-30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.

  7. Just Water? Social Disparities and Drinking Water Quality in California's San Joaquin Valley

    OpenAIRE

    Balazs, Carolina Laurie

    2011-01-01

    California's San Joaquin Valley is one of the world's richest agricultural regions yet it is also home to some of the greatest environmental problems, including drinking water contamination. After decades of intensive agriculture in the San Joaquin Valley (SJV), the region's aquifers and rivers are some of the most contaminated in the nation. This creates a notoriously difficult environmental problem to regulate, and related public health and environmental justice issues. Ninety-five perce...

  8. Water resources development in Santa Clara Valley, California: insights into the human-hydrologic relationship

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Jesse L.; Narasimhan, T.N.

    2000-06-01

    Groundwater irrigation is critical to food production and, in turn, to humankind's relationship with its environment. The development of groundwater in Santa Clara Valley, California during the early twentieth century is instructive because (1) responses to unsustainable resource use were largely successful; (2) the proposals for the physical management of the water, although not entirely novel, incorporated new approaches which reveal an evolving relationship between humans and the hydrologic cycle; and (3) the valley serves as a natural laboratory where natural (groundwater basin, surface watershed) and human (county, water district) boundaries generally coincide. Here, I investigate how water resources development and management in Santa Clara Valley was influenced by, and reflective of, a broad understanding of water as a natural resource, including scientific and technological innovations, new management approaches, and changing perceptions of the hydrologic cycle. Market demands and technological advances engendered reliance on groundwater. This, coupled with a series of dry years and laissez faire government policies, led to overdraft. Faith in centralized management and objective engineering offered a solution to concerns over resource depletion, and a group dominated by orchardists soon organized, fought for a water conservation district, and funded an investigation to halt the decline of well levels. Engineer Fred Tibbetts authored an elaborate water salvage and recharge plan that optimized the local water resources by integrating multiple components of the hydrologic cycle. Informed by government investigations, groundwater development in Southern California, and local water law cases, it recognized the limited surface storage possibilities, the spatial and temporal variability, the relatively closed local hydrology, the interconnection of surface and subsurface waters, and the value of the groundwater basin for its storage, transportation, and

  9. Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations

    Science.gov (United States)

    Hartzell, Stephen; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.

    2016-01-01

    Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response of the Livermore basin, a major structural depression in the California Coast Range Province bounded by active faults. Site response is calculated by two methods: the reference‐site spectral ratio method and a source‐site spectral inversion method. Longer‐period (≥1  s) amplification factors follow the same general pattern as Bouguer gravity anomaly contours. Site response spectra are inverted for shallow shear‐wave velocity profiles, which are consistent with independent information. Frequency–wavenumber analysis is used to analyze plane‐wave propagation across the Livermore Valley and to identify basin‐edge‐induced surface waves with back azimuths different from the source back azimuth. Finite‐element simulations in a 3D velocity model of the region illustrate the generation of basin‐edge‐induced surface waves and point out strips of elevated ground velocities along the margins of the basin.

  10. The environmental costs of mountaintop mining valley fill operations for aquatic ecosystems of the Central Appalachians.

    Science.gov (United States)

    Bernhardt, Emily S; Palmer, Margaret A

    2011-03-01

    Southern Appalachian forests are recognized as a biodiversity hot spot of global significance, particularly for endemic aquatic salamanders and mussels. The dominant driver of land-cover and land-use change in this region is surface mining, with an ever-increasing proportion occurring as mountaintop mining with valley fill operations (MTVF). In MTVF, seams of coal are exposed using explosives, and the resulting noncoal overburden is pushed into adjacent valleys to facilitate coal extraction. To date, MTVF throughout the Appalachians have converted 1.1 million hectares of forest to surface mines and buried more than 2,000 km of stream channel beneath mining overburden. The impacts of these lost forests and buried streams are propagated throughout the river networks of the region as the resulting sediment and chemical pollutants are transmitted downstream. There is, to date, no evidence to suggest that the extensive chemical and hydrologic alterations of streams by MTVF can be offset or reversed by currently required reclamation and mitigation practices. PMID:21449964

  11. Inversion of strong ground motion and teleseismic waveform data for the fault rupture history of the 1979 Imperial Valley, California, earthquake

    OpenAIRE

    Hartzell, Stephen H.; Heaton, Thomas H.

    1983-01-01

    A least-squares point-by-point inversion of strong ground motion and teleseismic body waves is used to infer the fault rupture history of the 1979 Imperial Valley, California, earthquake. The Imperial fault is represented by a plane embedded in a half-space where the elastic properties vary with depth. The inversion yields both the spatial and temporal variations in dislocation on the fault plane for both right-lateral strike-slip and normal dip-slip components of motion. Inversions are run f...

  12. Age, Stratigraphy, and Correlations of the Late Neogene Purisima Formation, Central California Coast Ranges

    Science.gov (United States)

    Powell, Charles L.; Barron, John A.; Sarna-Wojcicki, Andrei M.; Clark, Joseph C.; Perry, Frank A.; Brabb, Earl E.; Fleck, Robert J.

    2007-01-01

    The Purisima Formation is an important upper Miocene and Pliocene stratigraphic unit in central California, cropping out from the coast at Point Reyes north of San Francisco to more extensive exposures in the Santa Cruz Mountains to the south. The fine-grained rocks in the lower parts of the Purisima Formation record a latest Miocene transgressive event, whereas the middle and upper parts of the formation consist of increasingly clastic-rich siltstones and sandstones resulting from uplift of adjacent coastal regions and the Sierra Nevada during Pliocene transgressive and regressive sea-level events. Exposures of the Purisima occur in three different, fault-bounded, structural blocks - the Santa Cruz, Pigeon Point, and Point Reyes tectonic blocks - that complicate correlations and regional age assignments. We summarize and compare published and new biostratigraphic and geochronologic data for various exposures of the Purisima Formation on the basis of mollusks, diatoms, radiometric dating, magnetostratigraphy, tephrochronology, and strontium isotope dating. On the basis of these data, we conclude that the Purisima Formation ranges in age from the latest Miocene (about 7 Ma) to the late Pliocene (about 2.6 Ma). The Purisima Formation of Santa Cruz County, exposed in the sea cliffs from Santa Cruz to Rio del Mar, is here designated a supplementary reference section because it is the most complete and well studied Purisima section in central California.

  13. Distribution and Apparent Abundance of the Basking Shark, Cetorhinus maximus, off the Central and Southern California Coast, 1962-85

    OpenAIRE

    Squire, Jr. , James L.

    1990-01-01

    Basking sharks, Cetorhinus maximus, are frequently observed along the central and northwestern southern California coast during the winter and spring months. These large plankton feeding elasmobranchs, second in size only to the whale shark, Rhineodon typus, had been the subject of a small commercial fishery off California in the late 1940's and early 1950's for their liver oil, rich in vitamin A, and in later years for reduction into fish meal and oil (Roedel and Ripley, 1950). These fisher...

  14. The University of California Area Health Education Center Biomedical Library Program.

    Science.gov (United States)

    Jordan, Lynette G.

    This paper describes the University of California's Central San Joaquin Valley Area Health Education Center (AHEC) Biomedical Library Program, which is intended to improve library services in hospitals and other medical care institutions in the region and to coordinate future development of these services. A summary of the San Joaquin Valley AHEC…

  15. Importance of jumbo squid Dosidicus gigas (Orbigny, 1835) in the pelagic ecosystem of the central Gulf of California

    OpenAIRE

    Rosas-Luis, R. (Rigoberto); Salinas-Zavala, C.A; Kock, V; Del Monte Luna, Pablo; Morales Zárate, M.V.

    2008-01-01

    The Humboldt squid is an important predator in the pelagic ecosystem of the central Gulf of California to the commercial catch of this species has increased over the past decade, probable due to a decrease of several top predators (sharks, large pelagic fish and the marine mammals) and the optimal feeding conditions in this area. Its high abundance and important position in the pelagic food web was quantified through two trophic models of the pelagic ecosystem of the central Gulf of Californi...

  16. Outer boundary of major discharge areas of Death Valley regional flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The digital data set delineates the outer boundary of each major discharge area evaluated as part of the study. These areas were used to refine estimates of...

  17. Trace element and organochlorine contamination in prey and habitat of the Yuma clapper rail in the Imperial Valley, California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Yuma clapper rail (Rallus longirostris yumanensis) occurs along the Colorado River in Arizona and California, and in small marshes located around the Salton Sea...

  18. Tectonic setting of blueschist and island-arc terranes of west-central Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sedlock, R.L.

    1988-07-01

    Diverse oceanic rocks exposed in west-central Baja California (Mexico) are assigned to three shallowly dipping tectonic units. The lower plate is a subduction complex consisting of regionally metamorphosed blueschists and divided into structurally and petrologically distinct subterranes. The upper plate consists of Triassic-Lower Cretaceous arc rocks and overlapping mid-Cretaceous turbidites. A fault-bounded serpentinite-matrix melange between lower and upper plate rocks contains blueschist, eclogite, amphibolite, and variably serpentinized mafic and ultramafic blocks. Lower plate blueschists were metamorphosed in the late Early Cretaceous and uplifted along shallowly dipping normal faults during conditions of steady-state subduction. Exotic blocks of blueschist, eclogite, and amphibolite are derived from a cryptic terrane or terranes, record varied P-T-t histories, and were uplifted via tectonic emplacement or diapiric rise of serpentinite along the normal faults.

  19. Analysis of the apiclutural industry in relation to geothermal development and agriculture in the Imperial Valley, Imperial County, California

    Energy Technology Data Exchange (ETDEWEB)

    Atkins, E.L.

    1979-04-01

    PART I: Continuous exposure to 30 ppB H/sub 2/S increased lifespan of caged worker honey bees, Apis mellifera L., 33%; whereas, bees exposed > 13 days to 100 ppB and 300 ppB H/sub 2/S the lifespan was shortened 32% and 51%, respectively, over unexposed bees; bees exposed > 15 days to a combination of 300 ppB H/sub 2/S + 50 ppM CO/sub 2/ the lifespan was shortened 4.4% more that 300 ppB H/sub 2/S alone. The mean temperature and/or relative humidity did not exert a direct effect on the hazard to bees. A continuous exposure to 300 ppB SO/sub 2/ was detrimental to caged worker honey bees; and, a mean temperature of 27.2/sup 0/C was 75.7% more toxic than the same dosage at 16.7/sup 0/C. Worker bee lifespans exposed to 300 ppB SO/sub 2/ at 16.7/sup 0/C were shortened 13.5% and 79%, respectively, compared to unexposed bees. Therefore, both dosage and temperature exert direct effects on the hazards to bees. PART II: The status of the apicultural industry in Imperial County, California, was outlined giving a short characterization of the area in relation to the apicultural industry. Agriculture utilizes 500,000 intensely farmed acres which generated a 11-year average income of $370 million. Over 40 agricultural commodities are produced. The apicultural industry is intimately involved in 25% of the total gross agricultural income. In addition, most of the flora growing in the desert community which comprises the remainder of the county are very important to honey bees by providing sustaining nectar and/or pollen for brood rearing. The bee foraged flora provides substantial bee forage when colonies are located outside of the agriculutral area. It is concluded that geothermal resource development in the Imperial Valley is contemplated to have minimal effects on the apicultural industry.

  20. SIR2015-5175, Pahute Mesa-Oasis Valley and surrounding groundwater basins, Nevada and California, version 1.1

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This vector data set contains polygons representing the Pahute Mesa-Oasis Valley groundwater basin and surrounding groundwater basins in Nevada and California.

  1. Detrital zircon provenance analysis of the Great Valley Group, California: Evolution of an arc-forearc system

    Science.gov (United States)

    DeGraaff-Surpless, K.; Graham, S.A.; Wooden, J.L.; McWilliams, M.O.

    2002-01-01

    The improved resolution of sediment provenance from detrital zircon analysis of Great Valley stratigraphy enables recognition of previously undocumented arc magmatism and the evolution of regional drainage systems within the Cretaceous arc-forearc system related to uplift, magmatism, and structure in the arc. Great Valley detrital zircon age data confirm previous studies that indicate that the locus of the sediment source in the southern Sierra Nevada arc migrated east with the active volcanic front and suggest rapid rates of uplift and unroofing of the southern arc. Sacramento Valley detrital zircon age data indicate a more complex history of drainage in the northern Klamath-Sierran arc than previously documented. Detrital zircon age distributions from the Cache Creek section of the Great Valley Group broaden through time from nearly unimodal age distributions to signatures with multiple age peaks. This transition to more broadly distributed detrital zircon age spectra likely results from a combination of (1) expanding subaerial drainage systems from highly localized to more broadly distributed catchments; (2) changing shelf and submarine-canyon morphology with rising sea level and/or basin subsidence; (3) increased degree of dissection of the Klamath-Sierran arc; and (4) potential drainage capture and redirection within the arc. Sacramento Valley detrital zircon age data also record a pulse of Late Jurassic to Early Cretaceous magmatism in the northwestern Sierra Nevada arc, an age of Cordilleran magmatism and deformation represented by limited exposure in the modern Sierra Nevada. These results offer significant new insights into the evolution of a well-studied arc-forearc system.

  2. 75 FR 4745 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Science.gov (United States)

    2010-01-29

    ..., certain prohibitory rules, such as Rule 4308 (Boilers, Steam Generators, and Process Heaters 0.075 to 2 MMBtu/hr) and Rule 4307 (Boilers, Steam Generators, and Process Heaters 2 to 5 MMBtu/hr) would still... Context On February 20, 2008 (73 FR 9260), under sections 110(k)(2) and 110(k)(6) of the Clean Air...

  3. From Soil Aggregate to Watershed, from California's Central Valley to the Salton Sea - Agricultural Selenium Contamination across Ecosystems, Scales, and Disciplines

    OpenAIRE

    Kausch, Matteo Francesco

    2013-01-01

    Selenium (Se) is a trace element of great ecological importance whose environmental distribution is highly impacted by anthropogenic activity. In the 1980s, selenium was recognized as a major aquatic contaminant following widespread deformities and mortality among waterfowl hatchlings near the agricultural drainage evaporation ponds of the Kesterson Reservoir (CA, USA). Today, 400,000 km2 in the Western United States are threatened by agricultural selenium contamination, as are parts of Canad...

  4. Estimating soil matric potential in Owens Valley, California

    Science.gov (United States)

    Sorenson, Stephen K.; Miller, R.F.; Welch, M.R.; Groeneveld, D.P.; Branson, F.A.

    1988-01-01

    Much of the floor of the Owens Valley, California, is covered with alkaline scrub and alkaline meadow plant communities, whose existence is dependent partly on precipitation and partly on water infiltrated into the rooting zone from the shallow water table. The extent to which these plant communities are capable of adapting to and surviving fluctuations in the water table depends on physiological adaptations of the plants and on the water content, matric potential characteristics of the soils. Two methods were used to estimate soil matric potential in test sites in Owens Valley. The first was the filter-paper method, which uses water content of filter papers equilibrated to water content of soil samples taken with a hand auger. The other method of estimating soil matric potential was a modeling approach based on data from this and previous investigations. These data indicate that the base 10 logarithm of soil matric potential is a linear function of gravimetric soil water content for a particular soil. Estimates of soil water characteristic curves were made at two sites by averaging the gravimetric soil water content and soil matric potential values from multiple samples at 0.1 m depths derived by using the hand auger and filter paper method and entering these values in the soil water model. The characteristic curves then were used to estimate soil matric potential from estimates of volumetric soil water content derived from neutron-probe readings. Evaluation of the modeling technique at two study sites indicated that estimates of soil matric potential within 0.5 pF units of the soil matric potential value derived by using the filter paper method could be obtained 90 to 95% of the time in soils where water content was less than field capacity. The greatest errors occurred at depths where there was a distinct transition between soils of different textures. (Lantz-PTT)

  5. Pesticide Risk Communication, Risk Perception, and Self-Protective Behaviors among Farmworkers in California's Salinas Valley

    Science.gov (United States)

    Cabrera, Nolan L.; Leckie, James O.

    2009-01-01

    Agricultural pesticide use is the highest of any industry, yet there is little research evaluating farmworkers' understandings of the health risks chemical exposure poses. This study examines pesticide education, risk perception, and self-protective behaviors among farmworkers in California's Salinas Valley. Fifty current and former farmworkers…

  6. 75 FR 2079 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2010-01-14

    ...EPA is finalizing a limited approval and limited disapproval of revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). This action was proposed in the Federal Register on July 14, 2009 and concerns volatile organic compounds (VOCs) from confined animal facilities, such as dairies, cattle feedlots, and poultry and......

  7. Radiation balances of melting snow covers at an open site in the Central Sierra Nevada, California

    International Nuclear Information System (INIS)

    The radiation balances of melting snow packs for three seasons at an open site at the Central Sierra Snow Laboratory near Soda Springs, California were examined. The snow covers were examples of below-normal, near-normal and much-above-normal water equivalents. Two of the snow covers melted under generally clear skies in late spring while the other melted under cloudier conditions and at a time when less extraterrestrial radiation was available. Moreover, the snow covers were of very different densities, thereby allowing examination of a possible relationship between that characteristic and albedo. No such relationship was observed. Despite the dissimilarities in the conditions under which melt occurred, the disposition of solar radiation was similar for the three melt seasons. Albedos and their rates of decline through the melt season were similar for the three seasons. Absorbed solar radiation and a cloudiness index were useful predictors for daily net radiation, accounting for 71% of the total variance. (author)

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

    OpenAIRE

    Kang, Yongxiang; Łuczaj, Łukasz; Kang, Jin; Zhang, Shijiao

    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 a...

  9. 75 FR 1716 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-01-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule... Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation... Reviews I. Proposed Action On August 19, 2009 (74 FR 41826), EPA proposed a limited approval and...

  10. 75 FR 24408 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-05-05

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... FR 3680), EPA proposed to approve the following rule into the California SIP. Rule Rule title...

  11. 78 FR 6740 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Science.gov (United States)

    2013-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley United Air Pollution Control... FR 66429), EPA proposed to approve the following rule into the California SIP. Local agency Rule...

  12. 76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-11-03

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... Action On June 30, 2011 (76 FR 38340), EPA proposed to approve the following rule into the California...

  13. ERDA test facilities, East Mesa Test Site. Geothermal resource investigations, Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Detailed specifications which must be complied with in the construction of the ERDA Test Facilities at the East Mesa Site for geothermal resource investigations in Imperial Valley, California are presented for use by prospective bidders for the construction contract. The principle construction work includes a 700 gpm cooling tower with its associated supports and equipment, pipelines from wells, electrical equipment, and all earthwork. (LCL)

  14. An Analysis of Health Impacts Associated with Pollutant Response to Changes in Emissions In Different Regions of Central California

    Science.gov (United States)

    Tran, C.; Tanrikulu, S.; Beaver, S.; Hilken, H.

    2011-12-01

    Exposure to ozone and particulate matter has been shown to have considerable human health impacts. Currently major air basins of central California such as the San Francisco Bay Area (SFBA), Sacramento area, and the San Joaquin Valley (SJV) are all designated as in nonattainment of the Federal 8-hour ozone and 24-hour PM2.5 standards, despite California's comprehensive emission control programs for the last fifty years. Although these programs were very effective, decreasing anthropogenic emissions 40 to 50 percent in the region from 1990 to 2010 alone, the ambient response of pollutants was mixed and varied among these three interconnected regions. The purpose of this work was to investigate differences in each region's human health impact response to changes in emissions using the US EPA's BenMAP program. Inputs to BenMAP were prepared using the CMAQ model. Ambient concentrations were simulated for 2005. Then, anthropogenic emissions were reduced 10 to 60 percent across the board in 10 percent increments for the purpose of assessing pollutant responses to changes in emissions. BenMAP was run for each emission reduction scenario. The BenMAP results were normalized by county population to enable comparisons among counties that ranged from rural and agricultural to urban and densely populated. In all regions, the benefits of direct PM emission reductions were greater than those of similar precursor reductions. With respect to mortality rates, direct PM reductions produced the largest benefits in Nevada, Stanislaus, Tuolumne, and San Francisco Counties. For a 40 percent reduction in emissions, reductions in annual mortality rates ranged from 120 to 140 per million for these counties. Precursor emission reductions' benefits were maximized at the southern end of SJV, with Tulare showing the maximum reduction of around 83 mortalities per million. Monetized benefits of avoided mortalities as a result of direct PM emission reductions were significantly higher in

  15. Coho Salmon Habitat in a Changing Environment-Green Valley Creek, Graton, California

    Science.gov (United States)

    O'Connor, M. D.; Kobor, J. S.; Sherwood, M. N.

    2013-12-01

    Green Valley Creek (GVC) is a small (101 sq km) aquatic habitat refugium in the Russian River watershed (3,840 sq km) in coastal northern California. Coho salmon (Onchorhynchus kisutch) is endangered per the Federal Endangered Species Act, and GVC is one stream where coho have persisted. Fish surveys in GVC have found high species diversity, growth rates, and over-summer survival. The upper portion of GVC comprises a principal tributary (20 sq km) that provides spawning and rearing habitat for coho. The second principal tributary, Atascadero Creek, is comparable in size, but has few fish. Atascadero Creek and lower GVC have broad, densely vegetated floodplains. A Recovery Plan for the Central Coastal California coho Evolutionarily Significant Unit has been developed by the National Marine Fisheries Service (NMFS), which applies to the Russian River and its tributaries. Cooperative research regarding fish populations and habitat, a captive breeding and release program for native coho salmon, and efforts to plan for and restore habitat are ongoing. These regional efforts are particularly active in GVC, and participants include NMFS, the California Department of Fish and Wildlife, the Gold Ridge Resource Conservation District, the California Coastal Conservancy, the University of California Cooperative Extension, and the National Fish and Wildlife Foundation, among others. Our research focuses on hydrologic, geomorphic and hydrogeologic characteristics of the watershed in relation to aquatic habitat. Natural watershed factors contributing to habitat for coho include proximity to the coastal summer fog belt with cool temperatures, the Wilson Grove Formation aquifer that maintains dry season stream flow, and structural geology favorable for active floodplain morphology. Human impacts include water use and agriculture and rural residential development. Historic human impacts include stream clearing and draining of wetlands and floodplain for agriculture, which likely

  16. Glyphosate-resistant hairy fleabane documented in the Central Valley

    OpenAIRE

    Shrestha, Anil; Hanson, Bradley D.; Hembree, Kurt J

    2008-01-01

    In recent years, growers and pest consultants have reported poor control of the weed hairy fleabane in some areas of the Central Valley. Hairy fleabane seeds were collected from Esparto, Fresno and Reedley, Calif., and greenhouse-grown seedlings were treated at several different glyphosate rates and compared with an untreated control. None of the Esparto or Fresno plants survived glyphosate rates greater than 0.78 pounds acid equivalent per acre (lb ae/ac), while some of the plants from Reedl...

  17. Alternative Futures for the Region of Camp Pendleton California U.S.A. Oak Grove Valley

    OpenAIRE

    Toth, Richard E.

    1997-01-01

    The U.5. Environmental Protection Agency's (EPA Science Advisory Board, in its report Reducing Risk: Priorities and Strategies for Environmental Protection (U.S. EPA, 1990), identified the highest priority environmental risks to the United States, based primarily on geographic extent and irreversibility of effects. Habitat modification and loss of species diversity were ranked at the highest level of ecological risk. Habitat and species diversity are tightly coupled; species diversity at a re...

  18. Spatio-temporal evolution of aseismic ground deformation in the Mexicali Valley (Baja California, Mexico) from 1993 to 2010, using differential SAR interferometry

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.

    2015-11-01

    Ground deformation in Mexicali Valley, Baja California, Mexico, the southern part of the Mexicali-Imperial valley, is influenced by active tectonics and human activity, mainly that of geothermal fluid extraction in the Cerro Prieto Geothermal Field. Significant ground deformation, mainly subsidence (~ 18 cm yr-1), and related ground fissures cause severe damage to local infrastructure. The technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) has been demonstrated to be a very effective remote sensing tool for accurately measuring the spatial and temporal evolution of ground displacements over broad areas. In present study ERS-1/2 SAR and ENVISAT ASAR images acquired between 1993 and 2010 were used to perform a historical analysis of aseismic ground deformation in Mexicali Valley, in an attempt to evaluate its spatio-temporal evolution and improve the understanding of its dynamic. For this purpose, the conventional 2-pass DInSAR was used to generate interferograms which were used in stacking procedure to produce maps of annual aseismic ground deformation rates for different periods. Differential interferograms that included strong co-seismic deformation signals were not included in the stacking and analysis. The changes in the ground deformation pattern and rate were identified. The main changes occur between 2000 and 2005 and include increasing deformation rate in the recharge zone and decreasing deformation rate in the western part of the CPGF production zone. We suggested that these changes are mainly caused by production development in the Cerro Prieto Geothermal Field.

  19. Estimates of natural ground-water discharge and characterization of water quality in Dry Valley, Washoe County, West-Central Nevada, 2002-2003

    Science.gov (United States)

    Berger, David L.; Maurer, Douglas K.; Lopes, Thomas J.; Halford, Keith J.

    2004-01-01

    The Dry Valley Hydrographic Area is being considered as a potential source area for additional water supplies for the Reno-Sparks area, which is about 25 miles south of Dry Valley. Current estimates of annual ground-water recharge to Dry Valley have a considerable range. In undeveloped valleys, such as Dry Valley, long-term ground-water discharge can be assumed the same as long-term ground-water recharge. Because estimating ground-water discharge has more certainty than estimating ground-water recharge from precipitation, the U.S. Geological Survey, in cooperation with Washoe County, began a three-year study to re-evaluate the ground-water resources by estimating natural ground-water discharge and characterize ground-water quality in Dry Valley. In Dry Valley, natural ground-water discharge occurs as subsurface outflow and by ground-water evapotranspiration. The amount of subsurface outflow from the upper part of Dry Valley to Winnemucca and Honey Lake Valleys likely is small. Subsurface outflow from Dry Valley westward to Long Valley, California was estimated using Darcy's Law. Analysis of two aquifer tests show the transmissivity of poorly sorted sediments near the western side of Dry Valley is 1,200 to 1,500 square feet per day. The width of unconsolidated sediments is about 4,000 feet between exposures of tuffaceous deposits along the State line, and decreases to about 1,500 feet (0.5 mile) west of the State line. The hydraulic gradient east and west of the State line ranges from 0.003 to 0.005 foot per foot. Using these values, subsurface outflow to Long Valley is estimated to be 50 to 250 acre-feet per year. Areas of ground-water evapotranspiration were field mapped and partitioned into zones of plant cover using relations derived from Landsat imagery acquired July 8, 2002. Evapotranspiration rates for each plant-cover zone were multiplied by the corresponding area and summed to estimate annual ground-water evapotranspiration. About 640 to 790 acre-feet per

  20. Bats in Agroecosytems around California's Central Coast

    Science.gov (United States)

    Wayne, A.

    2014-12-01

    Bats in agroecosystems around California's Central Coast: A full quarter of California's land area is farmland. Crops account for 32.5 billion of California's GDP. Insect control is a big problem for farmers, and California bats eat only insects, saving farmers an estimated 3 to $53 billion a year. As farmers maximize crop yield, they use more pesticides, herbicides, and fertilizers, which contaminate runoff streams that bats drink from. Also, pesticide use kills bats' sole food source: insects. My research objective was to find out how farm management practices and landscape complexity affect bat diversity and activity, and to see which one affects bat activity more. We monitored 18 sites, including conventional, organic, and low and high-complexity landscapes. We noted more bat activity at sites with high complexity landscapes and organic practices than at sites with either low-complexity landscapes or conventional farming practices. I captured and processed bats and recorded data. I also classified insects collected from light traps. I learned how to handle bats and measure forearm length and weight, as well as how to indentify their gender. I took hair clippings and fecal samples, which yield data about the bats' diet. Their diet, in turn, gives us data about which pests they eat and therefore help control. I also learned about bats' echolocation: they have a special muscle over their ears that closes when they echolocate so that they don't burst their own eardrum. Also, some insects have evolved a special call that will disrupt bats echolocation so bats can't track it.

  1. Reconnaissance of Acid Drainage Sources and Preliminary Evaluation of Remedial Alternatives at the Copper Bluff Mine, Hoopa Valley Reservation, California

    Science.gov (United States)

    Alpers, Charles N.; Hunerlach, Michael P.; Hamlin, Scott N.; Zierenberg, Robert A.

    2003-01-01

    Acidic drainage from the inactive Copper Bluff mine cascades down a steep embankment into the Trinity River, on the Hoopa Valley Reservation in northern California. The Copper Bluff mine produced about 100,000 tons of sulfide-bearing copper-zinc-gold-silver ore during 1957?1962. This report summarizes the results of a water-resources investigation begun by the U.S. Geological Survey in 1994 with the overall objective of gathering sufficient geochemical, hydrologic, and geologic information so that a sound remediation strategy for the Copper Bluff mine could be selected and implemented by the Hoopa Valley Tribe. This study had the following specific objectives: (1) monitor the quality and quantity of the mine discharge, (2) determine seasonal variability of metal concentrations and loads, (3) map and sample the underground mine workings to determine sources of flow and suitability of mine plugging options, and (4) analyze the likely consequences of various remediation and treatment options. Analysis of weekly water samples of adit discharge over parts of two wet seasons (January to July 1995 and October 1995 to May 1996) shows that dissolved copper (Cu) and zinc (Zn) concentrations (in samples filtered with 0.20-micrometer membranes) varied systematically in a seasonal pattern. Metal concentrations increased dramatically in response to the first increase in discharge, or first flush, early in the wet season. The value of Zn/Cu in the adit discharge exhibited systematic seasonal variations; an annual Zn/Cu cycle was observed, beginning with values between 3 and 5 during the main part of the wet season, rising to values between 6 and 10 during the period of lowest discharge late in the dry season, and then dropping dramatically to values less than 3 during the first-flush period. Values of pH were fairly constant in the range of 3.1 to 3.8 throughout the wet season and into the beginning of the dry season, but rose to values between 4.5 and 5.6 during the period of

  2. Study of the Reed Dolomite Aided by Remotely Sensed Imagery, Central White-Inyo Range, Easternmost California

    Science.gov (United States)

    Ernst, W. G.; Paylor, Earnest D., II

    1996-01-01

    Remote-sensing methods are of great value in assessing the stratigraphy and geologic structure of inaccessible terrains, especially where lithologic contrasts are marked. In this report, we show that such techniques can be successfully applied to a massive carbonate unit, the Reed Dolomite, exposed in the Wacuoba Mountain, Blanco Mountain, and Mount Barcroft quadrangles of east-central California.

  3. Biodiversity effects and rates of spread of nonnative eucalypt woodlands in central California.

    Science.gov (United States)

    Fork, Susanne; Woolfolk, Andrea; Akhavan, Antonia; Van Dyke, Eric; Murphy, Shirley; Candiloro, Bree; Newberry, Todd; Schreibman, Sondra; Salisbury, Joshua; Wasson, Kerstin

    2015-12-01

    Woodlands comprised of planted, nonnative trees are increasing in extent globally, while native woodlands continue to decline due to human activities. The ecological impacts of planted woodlands may include changes to the communities of understory plants and animals found among these nonnative trees relative to native woodlands, as well as invasion of adjacent habitat areas through spread beyond the originally planted areas. Eucalypts (Eucalyptus spp.) are among the most widely planted trees worldwide, and are very common in California, USA. The goals of our investigation were to compare the biological communities of nonnative eucalypt woodlands to native oak woodlands in coastal central California, and to examine whether planted eucalypt groves have increased in size over the past decades. We assessed site and habitat attributes and characterized biological communities using understory plant, ground-dwelling arthropod, amphibian, and bird communities as indicators. Degree of difference between native and nonnative woodlands depended on the indicator used. Eucalypts had significantly greater canopy height and cover, and significantly lower cover by perennial plants and species richness of arthropods than oaks. Community composition of arthropods also differed significantly between eucalypts and oaks. Eucalypts had marginally significantly deeper litter depth, lower abundance of native plants with ranges limited to western North America, and lower abundance of amphibians. In contrast to these differences, eucalypt and oak groves had very similar bird community composition, species richness, and abundance. We found no evidence of "invasional meltdown," documenting similar abundance and richness of nonnatives in eucalypt vs. oak woodlands. Our time-series analysis revealed that planted eucalypt groves increased 271% in size, on average, over six decades, invading adjacent areas. Our results inform science-based management of California woodlands, revealing that while

  4. Bird Use of Imperial Valley Crops [ds427

    Data.gov (United States)

    California Department of Resources — Agriculture crops in the Imperial Valley of California provide valuable habitat for many resident and migratory birds and are a very important component of the...

  5. Prestige and alcohol in South Mexican fiesta: drinking with saint patrons in the central valleys of Oaxaca

    Directory of Open Access Journals (Sweden)

    Joanna Jadwiga Zamorska

    2015-01-01

    Full Text Available Food and alcohol are the key elements of celebrating a Mexican fiesta. I show that drinking at patronal feasts can be the way of constructing a respectful position, as presented in the ethnographic material collected in the three suburban communities of the Central Valleys of Oaxaca (in the years 2012–13. I discuss the relation between drinking alcohol at fiestas, participation and collective identity. I analyse the issue of prestige in the context drinking at fiestas and its relation to gender. I also discuss the role of alcohol in ritual exchanging of gifts at the patronal feasts which were under study and its relation with prestige. Other questions being analysed include the problem of refusing drink and the Catholic and non-Catholic critiques of patronal feasts as based on perceptions of excessive drinking.

  6. AIRBORNE PESTICIDES AND POPULATION DECLINES OF A CALIFORNIA ALPINE FROG

    Science.gov (United States)

    The mountain yellow-legged frog (Rana muscosa) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distribution and temporal variation of ...

  7. Significance of orthogonal flow in the Funeral Mountains metamorphic core complex, Death Valley, California: Insights from geochronology and microstructural analysis

    Science.gov (United States)

    Sauer, K. M.; Wells, M. L.; Hoisch, T. D.

    2013-12-01

    The Funeral Mountains metamorphic core complex (FMMCC) in Death Valley, California, exposes middle to lower crustal rocks of the Sevier-Laramide orogen in the footwall of the Boundary Canyon detachment (BCD). Monarch Canyon, located in the northwest section of the Funeral Mountains, exposes the structurally deepest rocks in the FMMCC. These Mesoproterozoic to Neoproterozoic metasedimentary rocks record upper amphibolite facies metamorphism with migmatites developed at the deepest levels. The Monarch Spring fault (MSF) juxtaposes migmatitic paragneisses below against pelitic schists, calcsilicate schists, and marbles above, and represents a deformed anatectic front. In the footwall of the BCD above the MSF, distributed ductile deformation and stratigraphically localized high-strain zones, termed intracore shear zones, are responsible for attenuation and local stratigraphic omission during top-northwest non-coaxial deformation. The relative contributions of Late Cretaceous-early Tertiary and Miocene extensional strains which manifest in the top-northwest fabrics remains unclear, and is being addressed by ongoing and combined thermochronologic, microstructural, and EBSD studies. Our working hypothesis is a polystage extensional history in the FMMCC, with Late Cretaceous extensional intracore shear zones locally reactivated during the Miocene. Below the MSF, migmatitic paragneisses lack similar greenschist to lower amphibolite facies top-northwest fabrics. These rocks instead exhibit heterogeneous strain and a weak to moderately developed northeast-trending mineral lineation, and a local, strong fabric asymmetry indicative of a top-southwest sense of shear. We propose that the anatectic front is an apparent zone of structural decoupling between top-southwest shear below and top-northwest shear above the MSF. Structural and geochronologic studies are currently underway to establish whether the orthogonally directed flow above and below the anatectic front were coeval or

  8. Chartkoff: Test Excavations at the May Site (CA-SIS-S7) in Seiad Valley, Northwestern California

    OpenAIRE

    Rock, James T.

    1989-01-01

    Test Excavations at the May Site (CA-SIS-S7) in Seiad Valley, Northwestern California. Joseph L. Chartkoff. Salinas: Coyote Press Archives of California Prehistory No. 17, 1988, vi + 80 pp., 2 maps, 12 figs., 31 tables, $6.20 (paper).

  9. Long-Term Impacts on Macroinvertebrates Downstream of Reclaimed Mountaintop Mining Valley Fills in Central Appalachia

    Science.gov (United States)

    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.

  10. Temporal changes of meadow and peatbog vegetation in the landscape of a small-scale river valley in Central Roztocze

    Directory of Open Access Journals (Sweden)

    Bożenna Czarnecka

    2015-07-01

    Full Text Available The Szum is a right-side tributary of the Tanew River crossing the southern escarpment zone of the Central Roztocze region (SE Poland. Downstream of the strict river break in a section between the 10th and 12th km of the river course in the Szum valley, meadow and peatbog complexes have developed, associated with semi-hydrogenic and marshy soils. In an area of approx. 13 ha of the most valuable non-forest habitats, a variety of plant communities have been identified, including habitats of the Natura 2000 network and habitats that are protected under the Regulation of the Minister of the Environment (2001. These are, for instance, meadow associations Lysimachio vulgaris-Filipenduletum, Lythro-Filipenduletum, Filipendulo ulmariae-Menthetum longifoliae, Angelico-Cirsietum oleracei, and Cirsietum rivularis. The moss–sedge and sphagnum bog communities comprise noteworthy associations Caricetum limosae, Rhynchosporetum albae, Caricetum lasiocarpae, Caricetum paniceo-lepidocarpae, Caricetum davallianae, and Sphagnetum magellanici. These communities are composed of ca. 160 vascular plant species and 40 moss and liverwort species. In 1999–2014, the greatest changes occurred within macroforb meadows, i.e. small Angelico-Cirsietum oleracei and Cirsietum rivularis patches have been transformed into Lysimachio vulgaris-Filipenduletum, while some patches of the latter association have been transformed into a Caricetum acutiformis rush. Several patches of bog-spring associations Caricetum paniceo-lepidocarpae and Carici canescentis-Agrostietum caninae have been irretrievably destroyed. Sphagnetum magellanici appears to be the least stable community among the preserved peatbogs. The changes of meadow and peatbog vegetation observed for the last 15 years are a consequence of natural processes that take place in the river valley and to a large extent human activity connected with the so-called small-scale water retention as well as the presence of a beaver

  11. Distribution, growth, and condition of salmonids in the central California Current Ecosystem.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fisheries Ecology Division of NOAA’s SWFSC conducts annual surveys of salmon and their ocean habitat in the coastal waters of northern California and southern...

  12. The Veneration and Visitation of the Graves of Saints in Soviet Central Asia. Insights from the Southern Ferghana Valley, Uzbekistan

    Czech Academy of Sciences Publication Activity Database

    Exnerová, Věra

    2015-01-01

    Roč. 83, č. 3 (2015), s. 501-536. ISSN 0044-8699 Institutional support: RVO:68378009 Keywords : graves of saints * Uzbekistan * Ferghana Valley * Soviet period * oral history * local practices Subject RIV: AB - History

  13. Contamination of groundwater under cultivated fields in an arid environment, Central Arava Valley, Israel

    International Nuclear Information System (INIS)

    Full text: The aim of this study was to understand the processes of contamination of groundwater in arid environments due to agriculture activity. A combination of physical, chemical and isotopic analyses was used to describe the hydrologic system and the trends in recharge of water and salts into the aquifer. The results indicate that intensive irrigation and fertilization substantially affected the quantity and quality of groundwater recharge. The water levels of shallow groundwater (2-5 m depth) rose during the agriculture season (September - March) by about 35 cm, indicating a significant contribution of irrigation water. It should be noted that there was no significant flood during this period. It is estimated that low irrigation efficiency of about 50 % caused recharge of about 3-4 million cubic meter of recycled irrigation water per year in the Arava Valley. Salt concentrations in soil profiles drilled down to depth of 2.5 m were low in cultivated fields and Wadi Arava, indicating that the irrigation water and intermittent floodwaters infiltrated and leached the salts downward. In contrast, there was an accumulation of various salts near the surface in undisturbed natural soil. There are 2 main sources of salt in contaminated ground water: (1) salts dissolved in the irrigation water itself, and (2) human additions include nitrogen from fertilizers and sewage ponds, as well as K. Mixed lines of different ions against TDS indicate that the dominant source of salinization is irrigation water from the surface. Nitrate concentrations increased in the aquifer, mainly in the last ten years. In parts of the aquifer that are closer to the surface, the increase was more rapid and the nitrate concentrations currently are higher. The nitrate concentration in the upper sub aquifer is over 50 mg/l and in a shallow local lens it ranges between 100-300 mg/l. The background nitrate concentrations, as found in the lower sub-aquifer, are 5-10 mg/l. Nitrate concentrations of

  14. Opinions from teachers in the Fresno area of Central California regarding the influence of mobile technology on their students’ learning

    OpenAIRE

    Navaridas, Fermín; Santiago, Raúl; Tourón, Javier

    2013-01-01

    This paper presents the most relevant results of a study in which opinions of the teachers in the area of Fresno (Central California, USA) about the effects of the integration of mobile devices into the teaching-learning process. Among other objectives, this study has tried to analyze the influence of mobile learning over three very important learning factors: affective-emotional (motivation), ethic-social (social skills) and the cognitive one (cognitive skills). In order...

  15. Air Pollution and Watershed Research in the Central Sierra Nevada of California: Nitrogen and Ozone

    Directory of Open Access Journals (Sweden)

    Carolyn Hunsaker

    2007-01-01

    Full Text Available Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3 and nitrogenous (N air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100–2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes.

  16. Monitoring the hydrologic system for potential effects of geothermal and ground-water development in the Long Valley Caldera, Mono County, California, USA

    International Nuclear Information System (INIS)

    In the early 1980's, renewed interest in the geothermal potential of the Long valley caldera, California, highlighted the need to balance the benefits of energy development with the established recreational activities of the area. The Long Valley Hydrologic Advisory Committee, formed in 1987, instituted a monitoring program to collect data during the early stages of resource utilization to evaluate potential effects on the hydrologic system. This paper reports that early data show declines in streamflow, spring flow, and ground-water levels caused by 6 years of below-average precipitation. Springs in the Hot Creek State Fish Hatchery area discharge water that is a mixture of nonthermal and hydrothermal components. Possible sources of nonthermal water have been identified by comparing deuterium concentrations in streams and springs. The equivalent amount of undiluted thermal water discharged from the springs was calculated on the basis of boron and chloride concentrations. Quantifying the thermal and nonthermal fractions of the total flow may allow researchers to assess changes in flow volume or temperature of the springs caused by ground-water or geothermal development

  17. Environmental magnetic implications of greigite (Fe3S4) formation in a 3 m.y. lake sediment record from Butte Valley, northern California Andrew

    Science.gov (United States)

    Roberts, P.; Reynolds, R.L.; Verosub, K.L.; Adam, D.P.

    1996-01-01

    Authigenic greigite (Fe3S4) has been identified in several horizons of lake beds in a 102-m core from Butte Valley, northern California, using mineral magnetic methods and x-ray diffraction analysis. The presence of greigite has several implications for the paleoenvironmental record from Butte Valley. First, its occurrence in 2.5 - 3.0 Ma strata confirms that greigite can persist in the geological record for long periods of time. Second, the detrital mineral magnetic record may be partially obscured by the presence of authigenic greigite and care must be taken in interpreting magnetic variations in the greigite-bearing zones as paleoclimate proxies. Third, differences in the timing of remanence acquisition for authigenic and detrital phases may compromise studies of high-frequency geomagnetic field variations. Fourth, greigite may also be significant as a paleoenvironmental indicator of lake and sediment chemistry. The magnetic detection of greigite may therefore provide important information about palcolimnological conditions. Copyright 1996 by the American Geophysical Union.

  18. Boundary of the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — 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...

  19. Analysis of twelve polymorphous bookmarks in the DNA of a population sample of the Costa Rican Central Valley

    International Nuclear Information System (INIS)

    To establish databases of allele frequencies in a Costa Rican Central Valley population sample. Peripheral blood samples from more than 40 individual were used to isolate DNA and analyze each sample with 10 dinucleotide repeat genetic markers and with 2 mini satellite repeats, using the polymerase chain reaction. Alleles were identified by comparison with DNA from CEPH family members. Genotypes were determined by labelling one of the two Pcr primers with 32P before amplification, electrophoresis in sequencing gels and autoradiography. Analysis of this data set indicates that these samples is in Hardy-Weinberg equilibrium and shows no evidence of linkage disequilibrium between markers. These data are compared with results from other human populations analyzed with the same markers, finding similarities in allele frequencies among them. Notably, the Costa Rican sample presents the lowest heterozygosity value, with 4 of the 10 dinucleotide markers tested, followed by a Cerdenian sample. In contrast, the two African samples presented the highest heterozygosity indexes with a larger number of alleles. (L. Jimenez)

  20. Studies of geology and hydrology in the Basin and Range province, southwestern United States, for isolation of high-level radioactive waste-characterization of the Death Valley region, Nevada and California

    International Nuclear Information System (INIS)

    The Death Valley region, Nevada and California, in the Basin and Range province, is an area of about 80,200 sq km located in southern Nevada and southeastern California. Precambrian metamorphic and intrusive basement rocks are overlain by a thick section of Paleozoic clastic and evaporitic sedimentary rocks. Mesozoic and Cenozoic rocks include extrusive and intrusive rocks and clastic sedimentary rocks. Structural features within the Death Valley indicate a long and complex tectonic evolution from late Precambrian to the present. Potential repository host media in the region include granite and other coarse-grained plutonic rocks, ashflow tuff, basaltic and andesitic lava flows, and basin fill. The Death Valley region is composed largely of closed topographic basins that are apparently coincident with closed groundwater flow systems. In these systems, recharge occurs sparingly at higher altitudes by infiltration of precipitation or by infiltration of ephemeral runoff. Discharge occurs largely by spring flow and by evaporation and transpiration in the playas. Death Valley proper, for which the region was named, is the ultimate discharge area for a large, complex system of groundwater aquifers that occupy the northeastern part of the region. The deepest part of the system consists of carbonate aquifers that connect closed topographic basins at depth. The discharge from the system occurs in several intermediate areas that are geomorphically, stratigraphically, and structurally controlled. Ultimately, most groundwater flow terminates by discharge to Death Valley; groundwater is discharged to the Colorado River from a small part of the region

  1. Social and economic factors of chile de agua (Capsicum Annum L. in three municipalities of the Central Valley in Oaxaca

    Directory of Open Access Journals (Sweden)

    María de los Ángeles Rodríguez Mendoza

    2013-01-01

    Full Text Available This issue was carried out in the municipalities of San Pablo Huixtepec, San Sebastián Abasolo and Culiapan of Guerrero as part of the Central Valleys of Oaxaca, Mexico. We studied the production system of Agua Chile, using the technique of structured interview,information was obtained that allowed us to determine and meet the current models of socio-economic benefits in the form of productionof this vegetable. The importance of this study is that the chile de agua despite being a highly profitable crop has been little studied, so it is not known the extent that can have, there are markets that offer potentially greater benefits to farmers, therefore it is important to know the current situation of farmers in order to provide alternatives to improve their economic situation. The results indicate that according to the practices of peasant production and the low level of technology that includes the type of fertilizers, agrochemicals to combat pests and diseases and low use of agricultural machinery, yields of 3.97 t ha-1 allow total revenues are higher than the costs of production. Besides the existence of limited marketing networks (primarily in local markets and in the Oaxaca city, is a competitive crop in terms of profitability for finance of small production units and furthermore, it is growing factor relevant food security of farming families.

  2. Forty Years of Winter: Cetaceans Observed During the Southbound Migration of Gray Whales, Eschrichtius robustus, Near Granite Canyon, Central California

    OpenAIRE

    Shelden, Kim E. W.; Rugh, David J.

    2010-01-01

    From December to February in most years from 1967 to 2007, observers counted gray whales, Eschrichtius robustus, from shore sites south of Carmel in central California. In addition to gray whales, other cetacean species were also recorded. These observations were summarized and compared among survey platforms and to ocean conditions. Eleven cetacean species were identified including eight odontocete species (killer whale, Orcinus orca; Pacific white-sided dolphin, Lagenorhynchus obliqui...

  3. An integrated ecosystem trophic model for the North and Central Gulf of California: An alternative view for endemic species conservation

    OpenAIRE

    Díaz-Uribe, J. Gabriel; Arreguín Sánchez, Francisco; Lercari-Bernier, Diego; Cruz Escalona, Víctor Hugo; Zetina Rejón, Manuel Jesús; Del Monte Luna, Pablo; Martínez-Aguilar, Susana

    2012-01-01

    Understanding of the intricate interactions of endemic species with anthropogenic impacts of diverse economic interests on ecosystems is of paramount importance to the implementation of effective con-servation programs. A trophic mass-balance model was used to analyze the structural properties of the North and Central Gulf of California (NC-GulfCal) ecosystem, the most important fishing area in Mexico and where conservation efforts for protecting the endangered endemic porpoise known as vaqui...

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

    Science.gov (United States)

    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. PMID:17537917

  5. 78 FR 63491 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    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... achievable by project contractors using best available cost-effective technology and best...

  6. Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA

    Science.gov (United States)

    Wylie, G.D.; Hothem, R.L.; Bergen, D.R.; Martin, L.L.; Taylor, R.J.; Brussee, B.E.

    2009-01-01

    The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history and habitat use of GGSs in 1995. During a series of investigations conducted from 1995 to the present, specimens of dead GGSs were opportunistically collected from the Colusa National Wildlife Refuge (CNWR), the Natomas Basin, and other sites in northern California. Whole snakes were stored frozen for potential future analysis. As funding became available, we analyzed tissues of 23 GGSs to determine the concentrations of total mercury (Hg) and other trace elements in livers and concentrations of Hg in brains and tail clips. Mercury concentrations (??g/g, wet weight) ranged from 0.08 to 1.64 in livers, 0.01 to 0.18 in brains, and 0.02 to 0.32 in tail clips. In livers, geometric mean concentrations (??g/g, dry weight) of arsenic (25.7) and chromium (1.02) were higher than most values from studies of other snakes. Mercury concentrations in tail clips were positively correlated with concentrations in livers and brains, with the most significant correlations occurring at the Natomas Basin and when Natomas and CNWR were combined. Results indicate the value of using tail clips as a nonlethal bioindicator of contaminant concentrations. ?? 2008 US Government.

  7. Red de mercadeo y rentabilidad de flor de corte en el Valle de Mexicali, Baja California, México Marketing network and profitability of cut flower for Mexicali Valley, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    Blancka Yesenia Samaniego-Gámez

    2012-06-01

    during 2004 with more than 122 million pesos, considering flower seed and cut flower production. Most of cut flowers produced in state of Baja California Norte is for export market, by this reason local market means an opportunity for introducing quality products at market prices from national companies. Mexicali city, by being near USA and together with its population economic wealth thanks to profitability of cotton and orchards production in Mexicali Valley, is one or the main producer region in the country. By this reason and thanks to great amount of flower shops located in the region the aim of describing marketing network and profitability for cut flower in Mexicali Valley is proposed. Market study and diagnose to make FODA analysis were developed, defining strategies in order to seize economic potential. Actual distribution networks and marketing system consist in moving cut flowers from production centers, Córdoba, Veracruz and Coatepec de Harinas district, state of Mexico, up to Mexicali Valley, Baja California, keeping quality and optimum vase life for final customer, also proper planning for production chain due not covered demand along year it is required, the population has economical potential and tradition to give flowers guaranteeing good profitability. Roses (Rosa gigantea and R. chinensis L., asian lilies (Lilium spp., chrysanthemum [Dendranthema x grandiflorum (Ramat Kitamura c. v. Polaris White], carnation (Dianthus caryophyllus, gerbera (Gerbera jamesonii H. Bolux ex Hook F. and oriental lilies (Lilium spp. are species with more consumers' interest.

  8. Evapotranspiration Units for the Diamond Valley Flow System Groundwater Discharge Area, Central Nevada, 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central...

  9. Water Level Altitude Contours for the Diamond Valley Flow System, Central Nevada, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central...

  10. Groundwater discharge areas for Antelope, Kobeh, and Monitor Valleys, Central Nevada, 1964

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset represents "phreatophyte areas" mapped as part of a groundwater reconnaissance effort in four valleys in central Nevada and published in 1964. The data...

  11. Groundwater Discharge Area for the Diamond Valley Flow System, Central Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central...

  12. Preliminary Image Map of the 2007 Grass Valley Fire Perimeter, Lake Arrowhead Quadrangle, San Bernardino County, California

    Science.gov (United States)

    Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

    2008-01-01

    In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

  13. Behavior of Repeating Earthquake Sequences in Central California and the Implications for Subsurface Fault Creep

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, D C; Nadeau, R; Burgmann, R

    2007-07-09

    Repeating earthquakes (REs) are sequences of events that have nearly identical waveforms and are interpreted to represent fault asperities driven to failure by loading from aseismic creep on the surrounding fault surface at depth. We investigate the occurrence of these REs along faults in central California to determine which faults exhibit creep and the spatio-temporal distribution of this creep. At the juncture of the San Andreas and southern Calaveras-Paicines faults, both faults as well as a smaller secondary fault, the Quien Sabe fault, are observed to produce REs over the observation period of March 1984-May 2005. REs in this area reflect a heterogeneous creep distribution along the fault plane with significant variations in time. Cumulative slip over the observation period at individual sequence locations is determined to range from 5.5-58.2 cm on the San Andreas fault, 4.8-14.1 cm on the southern Calaveras-Paicines fault, and 4.9-24.8 cm on the Quien Sabe fault. Creep at depth appears to mimic the behaviors seen of creep on the surface in that evidence of steady slip, triggered slip, and episodic slip phenomena are also observed in the RE sequences. For comparison, we investigate the occurrence of REs west of the San Andreas fault within the southern Coast Range. Events within these RE sequences only occurred minutes to weeks apart from each other and then did not repeat again over the observation period, suggesting that REs in this area are not produced by steady aseismic creep of the surrounding fault surface.

  14. Categories used to classify the basin-fill deposits in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the categories used to classify the basin-fill deposits in the Central Valley as either coarse-grained or fine-grained deposits. This...

  15. Bayesian Nitrate Source Apportionment to Individual Groundwater Wells in the Central Valley by use of Nitrogen, Oxygen, and Boron Isotopic Tracers

    Science.gov (United States)

    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. Land-use and land-cover dynamics and rural livelihood perspectives, in the semi-arid areas of Central Rift Valley of Ethiopia

    OpenAIRE

    Garedew, Efrem

    2010-01-01

    Global environmental changes in climate, land-use and bio-diversity are increasingly on top of scientific and political agenda. The impacts of climate change are manifested on all dimensions of food security: availability, accessibility, utilization and stability. This study presents land-use and land-cover (LULC) dynamics, rural livelihoods, and a dynamic simulation model of a socio-economical and environmental system in the Central Rift Valley of Ethiopia. Using different methods and approa...

  17. Facies, dissolution seams and stable isotope compositions of the Rohtas Limestone (Vindhyan Supergroup) in the Son valley area, central India

    Indian Academy of Sciences (India)

    S Banerjee; S K Bhattacharya; S Sarkar

    2005-02-01

    The early Mesoproterozoic Rohtas Limestone in the Son valley area of central India represents an overall shallowing-upward carbonate succession. Detailed facies analysis of the limestone reveals outer- to inner-shelf deposition in an open marine setting. Wave-ripples, hummocky cross strat- ifications and edgewise conglomerates argue against a deep marine depositional model for the Rohtas Limestone proposed earlier. Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution seams. Band-wise isotopic analysis reveals systematic short-term variations. Comparative enrichment of the heavier isotopes in the upper bands is attributed to early cementation from sea water and water derived from the lower band undergoing dissolution because of lowering of pH at depth. The short-term positive shifts in isotopic compositions in almost every upward gradational transition from a seamed band to a non-seamed band support the contention that dissolution seams here are of early diagenetic origin, although their formation was accentuated under overburden pressure.

  18. Detailed analysis of successive pTRMs carried by pyrrhotite in Himalayan metacarbonates: an example from Hidden Valley, Central Nepal

    Science.gov (United States)

    Crouzet, C.; Stang, H.; Appel, E.; Schill, E.; Gautam, P.

    2001-09-01

    Low-grade metacarbonates from the Tethyan Himalaya were sampled for palaeomagnetic studies in Hidden Valley (Central Nepal). The remanence is carried by pyrrhotite, evidenced by thermomagnetic runs of susceptibility (Hopkinson peak at ~300°C), alternating field demagnetization, isothermal remanent magnetization acquisition and subsequent thermal demagnetization. The palaeomagnetic directions reflect a Tertiary overprint after the main folding event, probably synchronous with the metamorphism. Normal and reverse remanence directions were separated and vary with altitude. It is also possible to retrieve several antiparallel components versus temperature during thermal demagnetization of a single sample. At higher altitudes (4920-5500m), the first component recorded is reverse (R1). At a lower temperature a normal component can be extracted (N1). For sites sampled at lower altitudes (4700-4900m), the high-temperature reverse component disappears but a medium-temperature reverse component (R2) demagnetized in a narrow temperature range can be identified in between two normal components (N1 at high temperature and N2 at low temperature). At the lowest altitudes (4450-4700m), only a normal component (N2) appears. The occurrence of successive normal and reverse polarities in one sample is interpreted as the record of successive reversals of the geomagnetic field during the post-metamorphic Tertiary cooling of the studied area. The polarity versus altitude function is a powerful argument for a thermomagnetic origin of the magnetization. No obvious rotations around a vertical axis with respect to the stable Indian plate are evidenced for the Tertiary. However, the inclination is not consistent with the expected inclination. Main Central Thrust ramping can be invoked to explain our observations. R1, N1 and N2 inclinations are slightly different and their tendency is consistent with tilting towards the north during magnetization acquisition. The minimum total amount of such

  19. Closed basin brine evolution and the influence of Ca-Cl inflow waters : Death Valley and Bristol Dry Lake California, Qaidam Basin, China, and Salar de Atacama, Chile

    OpenAIRE

    Lowenstein, T. K.; Risacher, François

    2009-01-01

    Diagenetic-hydrothermal brines, here called "hydrothermal Ca-Cl brines," have compositions that reflect interactions between groundwaters and rocks or sediments at elevated temperatures. Hydrothermal Ca-Cl brines reach the surface by convection-driven or topographically driven circulation, and discharge as springs or seeps along fault zones to become important inflow waters in many tectonically active closed basins. Case studies from (1) Qaidam Basin, China, (2) Death Valley, California, (3) ...

  20. An investigation of the genus Mesacanthus (Chordata: Acanthodii) from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland using traditional morphometrics

    OpenAIRE

    Baron, Matthew G.

    2015-01-01

    Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of diffe...

  1. Determining the origin of enigmatic bedrock structures using apatite (U-Th)/He thermochronology: Alabama and Poverty Hills, Owens Valley, California

    Science.gov (United States)

    Ali, G. A.; Reiners, P. W.; Ducea, M.

    2008-12-01

    The Alabama and Poverty Hills are enigmatic, topographic highs of crystalline basement surrounded by Neogene sediments in Owens Valley, California. The 150-km long Owens Valley, the westernmost graben of the Basin and Range Province, initiated at about 3 Ma, creating ~2-4 km of vertical relief from the Sierra Nevada and White/Inyos crests to the valley floor. Along the valley, the active right-lateral Owens Valley Fault Zone (OVFZ) accommodates a significant portion of Pacific-North American plate motion, creating an oblique dextral fault zone, with localized transpression along minor left-stepovers. The dominantly granitic Mesozoic rocks of the Alabama Hills are bounded by the OVFZ to the east, and the granitic and metavolcanic Mesozoic rocks of the Poverty Hills are located along an apparent 3-km left stepover of the OVFZ. The tectonic origin and geodynamic significance of both these structures are not known, but previously published hypotheses include: 1) transpressional uplifts as OVFZ-related flower structures; 2) down-dropped normal fault blocks; and 3) giant landslides from adjacent ranges. We measured apatite (U-Th)/He ages on 15 samples from the Alabama and Poverty Hills to understand the history of shallow crustal exhumation of these structures, and to potentially correlate them to rocks from adjacent ranges. Apatite He dating typically yields cooling ages corresponding to closure temperatures of ~55-65 °C, corresponding roughly to depths of ~2-3 km in the crust. The majority of apatite He ages from the Alabama Hills ranged from 58-70 Ma, but the far eastern, and lowest elevation sample showed ages of 51-55 Ma. The Poverty Hills shows younger ages of 40-65 Ma and no recognizable spatial pattern. Although the data do not conclusively rule out a transpressional uplift origin of the Poverty Hills, the rocks within them could not have been exhumed from depths greater than ~2-3 km in Owens Valley. Data from both structures are most consistent with down

  2. Faulting at Mormon Point, Death Valley, California: A low-angle normal fault cut by high-angle faults

    Science.gov (United States)

    Keener, Charles; Serpa, Laura; Pavlis, Terry L.

    1993-04-01

    New geophysical and fault kinematic studies indicate that late Cenozoic basin development in the Mormon Point area of Death Valley, California, was accommodated by fault rotations. Three of six fault segments recognized at Mormon Point are now inactive and have been rotated to low dips during extension. The remaining three segments are now active and moderately to steeply dipping. From the geophysical data, one active segment appears to offset the low-angle faults in the subsurface of Death Valley.

  3. Wild common bean in the Central Valley of Costa Rica: ecological distribution and molecular characterization

    Directory of Open Access Journals (Sweden)

    Rosa In\\u00E9s Gonz\\u00E1lez Torres

    2004-01-01

    Full Text Available Frijol silvestre en el Valle Central de Costa Rica: distribución ecológica y caracterización molecular. Este trabajo presenta una actualización sobre la distribución de las formas silvestres de fríjol común en Costa Rica, su ecología y su caracterización molecular. Ala fecha 22 poblaciones fueron encontradas en cuatro cuencas alrededor del Valle Central, generalmente en vegetaciones ruderales (frecuentemente bordes de cafetales, con estatuto de conservación variable (desde protegido a amenazado. Su caracterización molecular indica su pertenencia al acervo genético mesoamericano. Varios marcadores indican una variabilidad aumentada en las formas silvestres y permiten inferir la presencia de un fenómeno de flujo genético e introgresión desde materiales cultivados.

  4. 77 FR 10598 - BIOTECH Holdings Ltd., California Oil & Gas Corp., Central Minera Corp., Chemokine Therapeutics...

    Science.gov (United States)

    2012-02-22

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION BIOTECH Holdings Ltd., California Oil & Gas Corp., Central Minera Corp., Chemokine Therapeutics... current and accurate information concerning the securities of California Oil & Gas Corp. because it...

  5. Fine-scale simulation of ammonium and nitrate over the South Coast Air Basin and San Joaquin Valley of California during CalNex-2010

    Science.gov (United States)

    Kelly, James T.; Baker, Kirk R.; Nowak, John B.; Murphy, Jennifer G.; Markovic, Milos Z.; VandenBoer, Trevor C.; Ellis, Raluca A.; Neuman, J. Andrew; Weber, Rodney J.; Roberts, James M.; Veres, Patrick R.; Gouw, Joost A.; Beaver, Melinda R.; Newman, Sally; Misenis, Chris

    2014-03-01

    National ambient air quality standards (NAAQS) have been set for PM2.5 due to its association with adverse health effects. PM2.5 design values in the South Coast Air Basin (SoCAB) and San Joaquin Valley of California exceed NAAQS levels, and NH4+ and NO3- make up the largest fraction of total PM2.5 mass on polluted days. Here we evaluate fine-scale simulations of PM2.5 NH4+ and NO3- with the Community Multiscale Air Quality model using measurements from routine networks and the California Research at the Nexus of Air Quality and Climate Change 2010 campaign. The model correctly simulates broad spatial patterns of NH4+ and NO3- including the elevated concentrations in eastern SoCAB. However, areas for model improvement have been identified. NH3 emissions from livestock and dairy facilities appear to be too low, while those related to waste disposal in western SoCAB may be too high. Analyses using measurements from flights over SoCAB suggest that problems with NH3 predictions can influence NO3- predictions there. Offline ISORROPIA II calculations suggest that overpredictions of NHx in Pasadena cause excessive partitioning of total nitrate to the particle phase overnight, while underpredictions of Na+ cause too much partitioning to the gas phase during the day. Also, the model seems to underestimate mixing during the evening boundary layer transition leading to excessive nitrate formation on some nights. Overall, the analyses demonstrate fine-scale variations in model performance within and across the air basins. Improvements in inventories and spatial allocations of NH3 emissions and in parameterizations of sea spray emissions, evening mixing processes, and heterogeneous ClNO2 chemistry could improve model performance.

  6. Rodent consumption by Philodryas psammophidea (Serpentes: Colubridae), from the inter-andean dry valleys of central Bolivia

    OpenAIRE

    Quinteros-Muñoz, Oliver; Peñaranda, Diego A.; Navarro, Freddy

    2010-01-01

    In May 18, 2009 we found an adult female of Philodryas psammophidea (930 mm SVL), at a side of a crop field in the Tabacal valley (18º23'7.42" S – 64º38'7.88" W, 2015 m), Narciso Campero province southern Cochabamba, Bolivia. Ecologically, this valley belongs to the Inter-Andean Dry Forests of Bolivia. In the stomach of the snake probably killed by a settler, there was an adult female of Graomys domorum (Phyllotini; Sigmodontidae), a native rodent species widely distributed in the r...

  7. Rodent consumption by Philodryas psammophidea (Serpentes: Colubridae, from the inter-andean dry valleys of central Bolivia

    Directory of Open Access Journals (Sweden)

    Quinteros-Muñoz, Oliver

    2010-12-01

    Full Text Available In May 18, 2009 we found an adult female of Philodryas psammophidea (930 mm SVL, at a side of a crop field in the Tabacal valley (18º23'7.42" S – 64º38'7.88" W, 2015 m, Narciso Campero province southern Cochabamba, Bolivia. Ecologically, this valley belongs to the Inter-Andean Dry Forests of Bolivia. In the stomach of the snake probably killed by a settler, there was an adult female of Graomys domorum (Phyllotini; Sigmodontidae, a native rodent species widely distributed in the region.

  8. Ambient Air Pollution and Traffic Exposures and Congenital Heart Defects in the San Joaquin Valley of California

    Science.gov (United States)

    Padula, Amy M.; Tager, Ira B.; Carmichael, Suzan L.; Hammond, S. Katharine; Yang, Wei; Lurmann, Frederick; Shaw, Gary M.

    2013-01-01

    Background Congenital anomalies are a leading cause of infant morbidity and mortality. Studies suggest associations between environmental contaminants and some anomalies, although evidence is limited. Methods We used data from the California Center of the National Birth Defects Prevention Study and the Children's Health and Air Pollution Study to estimate the odds of 27 congenital heart defects with respect to quartiles of 7 ambient air pollutant and traffic exposures in California during the first two months of pregnancy, 1997–2006 (N=813 cases and N=828 controls). Results Particulate matter defects (aOR3rd Quartile=2.1; 95% CI: 1.1, 3.9) after adjusting for maternal race-ethnicity, education and multivitamin use. PM2.5 was associated with transposition of the great arteries (aOR3rd Quartile=2.6; 95% CI: 1.1, 6.5) and inversely associated with perimembranous ventricular septal defects (aOR4th Quartile=0.5; 95% CI: 0.2, 0.9). Secundum atrial septal defects were inversely associated with carbon monoxide (aOR4th Quartile=0.4; 95% CI: 0.2, 0.8) and PM2.5 (aOR4th Quartile=0.5; 95% CI: 0.3, 0.8). Traffic density was associated with muscular ventricular septal defects (aOR4th Quartile=3.0, 95% CI: 1.2, 7.8) and perimembranous ventricular septal defects (aOR3rd Quartile =2.4; 95% CI: 1.3, 4.6), and inversely associated with transposition of the great arteries (aOR4th Quartile=0.3; 95% CI: 0.1, 0.8). Conclusions PM10 and traffic density may contribute to the occurrence of pulmonary valve stenosis and ventricular septal defects, respectively. The results were mixed for other pollutants and had little consistency with previous studies. PMID:23772934

  9. Spatial variability of 137Cs inventories at reference sites in the Central Ebro valley, Spain, and potential climatic and lithological controls

    International Nuclear Information System (INIS)

    Reference sites at three locations in the central Ebro valley were selected to investigate the 137Cs content of several grain size fractions. Each site included both natural vegetated conditions and cultivated land and the three sites were characterized by different values of mean annual rainfall. The results obtained demonstrate the influence of both lithological and climatic factors on the spatial variability of 137Cs inventories

  10. Geophysical studies in the vicinity of Blue Mountain and Pumpernickel Valley near Winnemucca, north-central Nevada

    Science.gov (United States)

    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.

  11. Pilot evaluation of electricity-reliability and power-quality monitoring in California's Silicon Valley with the I-Grid(R) system

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph; Divan, Deepak; Brumsickle, William

    2004-02-01

    Power-quality events are of increasing concern for the economy because today's equipment, particularly computers and automated manufacturing devices, is susceptible to these imperceptible voltage changes. A small variation in voltage can cause this equipment to shut down for long periods, resulting in significant business losses. Tiny variations in power quality are difficult to detect except with expensive monitoring equipment used by trained technicians, so many electricity customers are unaware of the role of power-quality events in equipment malfunctioning. This report describes the findings from a pilot study coordinated through the Silicon Valley Manufacturers Group in California to explore the capabilities of I-Grid(R), a new power-quality monitoring system. This system is designed to improve the accessibility of power-quality in formation and to increase understanding of the growing importance of electricity reliability and power quality to the economy. The study used data collected by I-Grid sensors at seven Silicon Valley firms to investigate the impacts of power quality on individual study participants as well as to explore the capabilities of the I-Grid system to detect events on the larger electricity grid by means of correlation of data from the sensors at the different sites. In addition, study participants were interviewed about the value they place on power quality, and their efforts to address electricity-reliability and power-quality problems. Issues were identified that should be taken into consideration in developing a larger, potentially nationwide, network of power-quality sensors.

  12. Climate change adaptation strategies of maize producers of the Central Rift Valley of Ethiopia

    OpenAIRE

    Ahmed, Musa Hasen

    2016-01-01

    The impacts of climate change are considered to be strong in countries located in tropical Africa that depend on agriculture for their food, income and livelihood. Therefore, a better understanding of the local dimensions of adaptation strategies is essential to develop appropriate measures that will mitigate adverse consequences. Hence, this study was conducted to identify the most commonly used adaptation strategies that farm households practice among a set of options to withstand the effec...

  13. A multiple metrics approach to prioritizing strategies for measuring and managing reactive nitrogen in the San Joaquin Valley of California

    Science.gov (United States)

    Horowitz, Ariel I.; Moomaw, William R.; Liptzin, Daniel; Gramig, Benjamin M.; Reeling, Carson; Meyer, Johanna; Hurley, Kathleen

    2016-06-01

    Human alteration of the nitrogen cycle exceeds the safe planetary boundary for the use of reactive nitrogen (Nr). We complement global analysis by analyzing regional mass flows and the relative consequences of multiple chemical forms of Nr as they ‘cascade’ through multiple environmental media. The goals of this paper are (1) to identify the amounts of Nr that flow through a specific nitrogen rich region, (2) develop multiple metrics to characterize and compare multiple forms of Nr and the different damages that they cause, and (3) to use these metrics to assess the most societally acceptable and cost effective means for addressing the many dimensions of Nr damage. This paper uses a multiple metrics approach that in addition to mass flows considers economic damage, health and mitigation costs and qualitative damages to evaluate options for mitigating Nr flows in California’s San Joaquin Valley (SJV). Most analysis focuses attention on agricultural Nr because it is the largest flow in terms of mass. In contrast, the multiple metrics approach identifies mobile source Nr emissions as creating the most economic and health damage in the SJV. Emissions of Nr from mobile sources are smaller than those from crop agriculture and dairy in the SJV, but the benefits of abatement are greater because of reduced health impacts from air pollution, and abatement costs are lower. Our findings illustrate the benefit of a comprehensive multiple metrics approach to Nr management.

  14. Simulated effects of climate change on the Death Valley regional ground-water flow system, Nevada and California

    International Nuclear Information System (INIS)

    The US Geological Survey, in cooperation with the US Department of Energy, is evaluating the geologic and hydrologic characteristics of the Death Valley regional flow system as part of the Yucca Mountain Project. As part of the hydrologic investigation, regional, three-dimensional conceptual and numerical ground-water-flow models have been developed to assess the potential effects of past and future climates on the regional flow system. A simulation that is based on climatic conditions 21,000 years ago was evaluated by comparing the simulated results to observation of paleodischarge sites. Following acceptable simulation of a past climate, a possible future ground-water-flow system, with climatic conditions that represent a doubling of atmospheric carbon dioxide, was simulated. The steady-state simulations were based on the present-day, steady-state, regional ground-water-flow model. The finite-difference model consisted of 163 rows, 153 columns, and 3 layers and was simulated using MODFLOWP. Climate changes were implemented in the regional ground-water-flow model by changing the distribution of ground-water recharge. Global-scale, average-annual, simulated precipitation for both past- and future-climate conditions developed elsewhere were resampled to the model-grid resolution. A polynomial function that represents the Maxey-Eakin method for estimating recharge from precipitation was used to develop recharge distributions for simulation

  15. The hydrogeochemistry of a heavily used aquifer in the Mexican wine-producing Guadalupe Valley, Baja California

    Science.gov (United States)

    Daesslé, L. W.; Mendoza-Espinosa, L. G.; Camacho-Ibar, V. F.; Rozier, W.; Morton, O.; van Dorst, L.; Lugo-Ibarra, K. C.; Quintanilla-Montoya, A. L.; Rodríguez-Pinal, A.

    2006-10-01

    The Guadalupe Valley aquifer is the only water source for one of the most important wine industries in Mexico, and also the main public water supply for the nearby city of Ensenada. This groundwater is monitored for major ion, N-NO3, P-PO4, Fe, As, Se, Mo, Cd, Cu, Pb, Zn and Sb concentrations, as well as TDS, pH, dissolved oxygen and temperature. High concentrations of N-NO3 (26 mg l-1), Se (70 μg l-1), Mo (18 μg l-1) and Cu (4.3 μg l-1) suggest that groundwater is being polluted by the use of fertilizers only in the western section of the aquifer, known as El Porvenir graben. Unlike the sites located near the main recharge area to the East of the aquifer, the water in El Porvenir graben has low tritium concentrations (water residence time. No significant variations in water quality (generally water quality. However, the wells nearest to the main recharge area in the Eastern aquifer show a slight but constant increase in TDS with time, probably as a result of the high (˜200 L S-1) uninterrupted extraction of water at this specific recharge site. Relatively high As concentrations for the aquifer (10.5 μg l-1) are only found near the northern limit of the basin associated with a geological fault.

  16. Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

    International Nuclear Information System (INIS)

    Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35 degrees N., long 115 degrees W and lat 38 degrees N., long 118 degrees W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system

  17. Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    D`Agnese, F.A.; Faunt, C.C.; Turner, A.K.; Hill, M.C.

    1997-12-31

    Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35{degrees}N., long 115{degrees}W and lat 38{degrees}N., long 118{degrees}W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system.

  18. Emergency Assessment of Debris-Flow Hazards from Basins Burned by the 2007 Slide and Grass Valley Fires, San Bernardino County, Southern California

    Science.gov (United States)

    Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Bauer, Mark A.; Stitt, Susan C.; Knifong, Donna L.; McNamara, Bernard J.; Roque, Yvonne M.

    2007-01-01

    INTRODUCTION The objective of this report is to present a preliminary emergency assessment of the potential for debris-flow generation from basins burned by the Slide and Grass Valley Fires in San Bernardino County, southern California in 2007. Debris flows are among the most hazardous geologic phenomena; debris flows that followed wildfires in southern California in 2003 killed 16 people and caused tens of millions of dollars of property damage. A short period of even moderate rainfall on a burned watershed can lead to debris flows. Rainfall that is normally absorbed into hillslope soils can run off almost instantly after vegetation has been removed by wildfire. This causes much greater and more rapid runoff than is normal from creeks and drainage areas. Highly erodible soils in a burn scar allow flood waters to entrain large amounts of ash, mud, boulders, and unburned vegetation. Within the burned area and downstream, the force of rushing water, soil, and rock can destroy culverts, bridges, roadways, and buildings, potentially causing injury or death. This emergency debris-flow hazard assessment is presented as relative ranking of the predicted median volume of debris flows that can issue from basin outlets in response to 3.50 inches (88.90 mm) of rainfall over a 3-hour period. Such a storm has a 10-year return period. The calculation of debris flow volume is based on a multiple-regression statistical model that describes the median volume of material that can be expected from a recently burned basin as a function of the area burned at high and moderate severity, the basin area with slopes greater than or equal to 30 percent, and triggering storm rainfall. Cannon and others (2007) describe the methods used to generate the hazard maps. Identification of potential debris-flow hazards from burned drainage basins is necessary to issue warnings for specific basins, to make effective mitigation decisions, and to help plan evacuation timing and routes.

  19. A Survey of \\delta18O and \\delta15N Ratios in Ground Water from an Agricultural Community in the San Joaquin Valley, California

    Science.gov (United States)

    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.

  20. Remote sensing and ichthyoplankton ecology of coastal upwelling fronts off central California

    Science.gov (United States)

    Bjorkstedt, Eric Peter

    1998-11-01

    Recruitment to many marine populations is determined by processes affecting survival and transport of planktonic larvae. Coastal upwelling poses a trade-off between larval access to high productivity supported by upwelled nutrients and increased risk of offshore transport and failure to return to coastal habitats. I used plankton surveys, remote sensing, and a simple model to investigate the role of coastal upwelling fronts and behavior in pelagic ecology and recruitment success, focussing on rockfish (Sebastes spp.) off central California. Distributions of early stage larvae suggest that coastal upwelling fronts reduce offshore transport of rockfish larvae, in contrast to distributions of taxa with life histories that minimize larval exposure to strong upwelling. Coincident distributions of larval fish, prey (i.e., small copepods and invertebrate eggs) and phytoplankton patches indicate that coastal upwelling fronts provide enhanced foraging conditions for larvae. Thus, coastal upwelling fronts may allow coastal taxa to successfully exploit high productivity during the upwelling season while reducing the risk of offshore transport. I developed a novel method for utilizing a single HF radar to resolve currents and detect fronts that matched sea surface temperature fronts generated by coastal upwelling. Fronts and currents detected with NF radar affect distributions and transport of planktonic larval fish and intertidal barnacle larvae, demonstrating that remote sensing with HF radar can support field and modelling research on ecological dynamics in coastal marine systems. I used an empirically-based model that incorporated the advection-foraging trade-off and long-distance swimming as an active settlement behavior to investigate optimal settlement strategies as a function of pelagic transport and growth. For parameters loosely describing pelagic stages of rockfish, the model predicts optimal settling strategies (ages and sizes) for pelagic juveniles that roughly

  1. Residential agricultural pesticide exposures and risk of neural tube defects and orofacial clefts among offspring in the San Joaquin Valley of California.

    Science.gov (United States)

    Yang, Wei; Carmichael, Suzan L; Roberts, Eric M; Kegley, Susan E; Padula, Amy M; English, Paul B; Shaw, Gary M

    2014-03-15

    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

  2. Biomonitoring with Micronuclei Test in Buccal Cells of Female Farmers and Children Exposed to Pesticides of Maneadero Agricultural Valley, Baja California, Mexico

    Science.gov (United States)

    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

  3. Altitudes of the top of model layers in the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the model grid and altitudes of the top of the 10 model layers and base of the model simulated in the transient hydrologic model of the...

  4. The History of Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2005-01-01

    @@ Just as Manchester was once the center for indus trial progress, the microelectronics industry also has a heartland. Silicon Valley is located in a thirty by ten miles strip between San Francisco and San Jose,California.

  5. Potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — 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...

  6. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — 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...

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

    OpenAIRE

    Piperno, D. R.; Moreno, J. E.; J Iriarte; 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 l...

  8. Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada

    OpenAIRE

    J. M. Creamean; A. P. Ault; White, A B; P. J. Neiman; Ralph, F.M.; Minnis, P.; K. A. Prather

    2015-01-01

    Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009–2011), the variability and associated impacts of different aerosol sources on precipitation were investigated in the California Sierra Nevada using an aerosol tim...

  9. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California

    OpenAIRE

    Rejmanek, Daniel; Miller, Melissa A.; Michael E Grigg; Crosbie, Paul R.; Conrad, Patricia A.

    2010-01-01

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was an...

  10. Intraday monitoring of granitic exfoliation sheets with LiDAR and thermal imaging (Yosemite Valley, California, USA)

    Science.gov (United States)

    Guerin, Antoine; Derron, Marc-Henri; Jaboyedoff, Michel; Abellán, Antonio; Dubas, Olivier; Collins, Brian D.; Stock, Greg M.

    2016-04-01

    Rockfall activity in Yosemite Valley is often linked to the presence of exfoliation sheets associated with other structures such as faults, joints or geological contacts. Daily and seasonal temperature variations or freeze-thaw cycles may strongly promote crack propagation along discontinuities, ultimately leading to rockfalls (Stock et al., 2013). However, little is known concerning the impact of thermal variations on rock face deformation, despite its occurrence at all times of year. To understand the influence of daily temperature fluctuations on the behavior of exfoliation joints (i.e., fractures separating exfoliation sheets), we carried out two different experiments in October 2015: (a) We first monitored a sub-vertical granodiorite flake (19 m by 4 m by 0.1 m ; Collins and Stock, 2014) for 24 consecutive hours using LiDAR and infrared thermal sensors; (b) We monitored a rock cliff (60 m by 45 m) composed of tens of exfoliation sheets located on the southeast face of El Capitan (an ~1000-m-tall cliff located in western Yosemite Valley) for several hours (from 05:30 pm to 01:30 am) to investigate the diurnal cooling effect on rocks of different lithologies. To calibrate the raw apparent temperature measured by the thermal imager (FLIR T660 infrared camera), we fixed pieces of reflective paper (aluminum foil) and black duct tape on both monitored cliffs to measure the reflected temperature and the emissivity of the different rocks. In addition, ambient temperature and relative humidity readings were performed for each acquisition. We then compared the calibrated temperatures to the values registered by resistance temperature detectors (Pt100 sensors), also attached to the rock. Finally, we compared the millimeter scale deformations observed with LiDAR to the values measured by manual crackmeters (standard analog comparators with springs) installed beforehand in the fractures. For the first experiment (24-hour monitoring), a series of measurements were carried

  11. 76 FR 38589 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2011-07-01

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) portion...

  12. Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: a potential source of geogenic Cr(VI) to groundwater

    Science.gov (United States)

    Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

    2011-01-01

    Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization’s maximum contaminant level for drinking water (50 μg L−1) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 μg L−1. To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to ~1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged from 0 to 42 μg kg−1, representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a

  13. Passive remote sensing of large-scale methane emissions from Oil Fields in California's San Joaquin Valley and validation by airborne in-situ measurements - Results from COMEX

    Science.gov (United States)

    Gerilowski, Konstantin; Krautwurst, Sven; Thompson, David R.; Thorpe, Andrew K.; Kolyer, Richard W.; Jonsson, Haflidi; Krings, Thomas; Frankenberg, Christian; Horstjann, Markus; Leifer, Ira; Eastwood, Michael; Green, Robert O.; Vigil, Sam; Fladeland, Matthew; Schüttemeyer, Dirk; Burrows, John P.; Bovensmann, Heinrich

    2016-04-01

    The CO2 and MEthane EXperiment (COMEX) was a NASA and ESA funded campaign in support of the HyspIRI and CarbonSat mission definition activities. As a part of this effort, seven flights were performed between June 3 and September 4, 2014 with the Methane Airborne MAPper (MAMAP) remote sensing instrument (operated by the University of Bremen in cooperation with the German Research Centre for Geosciences - GFZ) over the Kern River, Kern Front, and Poso Creek Oil Fields located in California's San Joaquin Valley. MAMAP was installed for the flights aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft, together with: a Picarro fast in-situ greenhouse gas (GHG) analyzer operated by the NASA Ames Research Center, ARC; a 5-hole turbulence probe; and an atmospheric measurement package operated by CIRPAS measuring aerosols, temperature, dew-point, and other atmospheric parameters. Three of the flights were accompanied by the Next Generation Airborne Visual InfraRed Imaging Spectrometer (AVIRIS-NG), operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology, installed aboard a second Twin Otter aircraft. Large-scale, high-concentration CH4 plumes were detected by the MAMAP instrument over the fields and tracked over several kilometers. The spatial distribution of the MAMAP observed plumes was compared to high spatial resolution CH4 anomaly maps derived by AVIRIS-NG imaging spectroscopy data. Remote sensing data collected by MAMAP was used to infer CH4 emission rates and their distributions over the three fields. Aggregated emission estimates for the three fields were compared to aggregated emissions inferred by subsequent airborne in-situ validation measurements collected by the Picarro instrument. Comparison of remote sensing and in-situ flux estimates will be presented, demonstrating the ability of airborne remote sensing data to provide accurate emission estimates for concentrations above the

  14. An estimated potentiometric surface of the Death Valley region, Nevada and California, developed using geographic information system and automated interpolation techniques

    International Nuclear Information System (INIS)

    An estimated potentiometric surface was constructed for the Death Valley region, Nevada and California, from numerous, disparate data sets. The potentiometric surface was required for conceptualization of the ground-water flow system and for construction of a numerical model to aid in the regional characterization for the Yucca Mountain repository. Because accurate, manual extrapolation of potentiometric levels over large distances is difficult, a geographic-information-system method was developed to incorporate available data and apply hydrogeologic rules during contour construction. Altitudes of lakes, springs, and wetlands, interpreted as areas where the potentiometric surface intercepts the land surface, were combined with water levels from well data. Because interpreted ground-water recharge and discharge areas commonly coincide with groundwater basin boundaries, these areas also were used to constrain a gridding algorithm and to appropriately place local maxima and minima in the potentiometric-surface map. The resulting initial potentiometric surface was examined to define areas where the algorithm incorrectly extrapolated the potentiometric surface above the land surface. A map of low-permeability rocks overlaid on the potentiometric surface also indicated areas that required editing based on hydrogeologic reasoning. An interactive editor was used to adjust generated contours to better represent the natural water table conditions, such as large hydraulic gradients and troughs, or ''vees''. The resulting estimated potentiometric-surface map agreed well with previously constructed maps. Potentiometric-surface characteristics including potentiometric-surface mounds and depressions, surface troughs, and large hydraulic gradients were described

  15. An Impact Crater in Palm Valley, Central Australia?

    CERN Document Server

    Hamacher, Duane W; O'Neill, Craig; Britton, Tui R

    2012-01-01

    We explore the origin of a ~280 m wide, heavily eroded circular depression in Palm Valley, Northern Territory, Australia using gravity, morphological, and mineralogical data collected from a field survey in September 2009. From the analysis of the survey, we debate probable formation processes, namely erosion and impact, as no evidence of volcanism is found in the region or reported in the literature. We argue that the depression was not formed by erosion and consider an impact origin, although we acknowledge that diagnostics required to identify it as such (e.g. meteorite fragments, shatter cones, shocked quartz) are lacking, leaving the formation process uncertain. We encourage further discussion of the depression's origin and stress a need to develop recognition criteria that can help identify small, ancient impact craters. We also encourage systematic searches for impact craters in Central Australia as it is probable that many more remain to be discovered.

  16. Detection and Measurement of Land Subsidence Using Global Positioning System Surveying and Interferometric Synthetic Aperture Radar, Coachella Valley, California, 1996-2005

    Science.gov (United States)

    Sneed, Michelle; Brandt, Justin T.

    2007-01-01

    Land subsidence associated with ground-water-level declines has been investigated by the U.S. Geological Survey in the Coachella Valley, California, since 1996. Ground water has been a major source of agricultural, municipal, and domestic supply in the valley since the early 1920s. Pumping of ground water resulted in water-level declines as large as 15 meters (50 feet) through the late 1940s. In 1949, the importation of Colorado River water to the southern Coachella Valley began, resulting in a reduction in ground-water pumping and a recovery of water levels during the 1950s through the 1970s. Since the late 1970s, demand for water in the valley has exceeded deliveries of imported surface water, resulting in increased pumping and associated ground-water-level declines and, consequently, an increase in the potential for land subsidence caused by aquifer-system compaction. Global Positioning System (GPS) surveying and interferometric synthetic aperture radar (InSAR) methods were used to determine the location, extent, and magnitude of the vertical land-surface changes in the southern Coachella Valley. GPS measurements made at 13 geodetic monuments in 1996 and in 2005 in the southern Coachella Valley indicate that the elevation of the land surface had a net decline of 333 to 22 millimeters ?58 millimeters (1.1 to 0.07 foot ?0.19 foot) during the 9-year period. Changes at 10 of the 13 monuments exceeded the maximum uncertainty of ?58 millimeters (?0.19 foot) at the 95-percent confidence level, indicating that subsidence occurred at these monuments between June 1996 and August 2005. GPS measurements made at 20 geodetic monuments in 2000 and in 2005 indicate that the elevation of the land surface changed -312 to +25 millimeters ?42 millimeters (-1.0 to +0.08 foot ?0.14 foot) during the 5-year period. Changes at 14 of the 20 monuments exceeded the maximum uncertainty of ?42 millimeters (?0.14 foot) at the 95-percent confidence level, indicating that subsidence occurred at

  17. Incidence of first primary central nervous system tumors in California, 2001–2005: children, adolescents and teens

    OpenAIRE

    Brown, Monica; Schrot, Rudolph; Bauer, Katrina; Dodge, Jennifer

    2009-01-01

    This study used data from the California Cancer Registry to comprehensively examine first primary central nervous system tumors (PCNST) by the International Classification of Childhood Cancers (ICCC) diagnostic groups and to compare their incidence by age groups, sex, race/ethnicity, socioeconomic status and tumor behavior. The study period, 2001–2005, represents the first 5 years of benign PCNST data collection in the state. The age-adjusted incidence rates were 2.1 for malignant and 1.3 for...

  18. Bioavailability and fate of phosphorus in constructed wetlands receiving agricultural runoff in the San Joaquin Valley, California.

    Science.gov (United States)

    Maynard, Jonathan J; O'Geen, Anthony T; Dahlgren, Randy A

    2009-01-01

    Elevated nutrient concentrations in agricultural runoff contribute to seasonal eutrophication and hypoxia in the lower portion of the San Joaquin River, California. Interception and filtration of agricultural runoff by constructed wetlands may improve water quality of return flows ultimately destined for major water bodies. This study evaluated the efficacy of two small flow-through wetlands (2.3 and 7.3 ha; hydraulic residence time = 11 and 31 h) for attenuating various forms of P from irrigation tailwaters during the 2005 irrigation season (May to September). Our goal was to examine transformations and removal efficiencies for bioavailable P in constructed wetlands. Inflow and outflow water volumes were monitored continuously and weekly water samples were collected to measure total P (TP), dissolved-reactive P (DRP), and bioavailable P (BAP). Suspended sediment was characterized and fractionated into five operationally-defined P fractions (i.e., NH4Cl, bicarbonate-dithionite, NaOH, HCl, residual) to evaluate particulate P (PP) transformations. DRP was the major source of BAP with the particulate fraction contributing from 11 to 26%. On a seasonal basis, wetlands removed 55 to 65% of PP, 61 to 63% of DRP, 57 to 62% of BAP, and 88 to 91% of TSS. Sequential fractionation indicated that the bioavailable fraction of PP was largely associated with clay-sized particles that remain in suspension, while less labile P forms preferentially settle with coarser sediment. Thus, removal of potentially bioavailable PP is dependent on factors that promote particle settling and allow for the removal of colloids. This study suggests that treatment of tailwaters in small, flow-through wetlands can effectively remove BAP. Wetland design and management strategies that enhance sedimentation of colloids can improve BAP retention efficiency. PMID:19141827

  19. Contamination of groundwater under cultivated fields in an arid environment, Central Arava Valley, Israel

    International Nuclear Information System (INIS)

    The aim of this study was to understand the processes of contamination of groundwater in arid environments due to agriculture activity. A combination of physical, chemical and isotopic analyses was used to describe the hydrologic system and the trends in recharge of water and salts into the aquifer. The results indicate that intensive irrigation and fertilization substantially affected the quantity and quality of groundwater recharge

  20. Stream-gage locations where streamflow gains/losses were quantified along the Central Valley surface-water network

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the name and location for the diversions from the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central...

  1. Historical boundary of the Death Valley regional ground-water flow system by Harrill and Prudic (1998), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a historical definition of the extent (approximately 42,600 square-kilometers) and lateral boundary of the Death Valley regional...

  2. VALUING SOIL CONSERVATION PRACTICES USING CONTINGENT VALUATION TECHNIQUE: EVIDENCE FROM THE CENTRAL RIFT VALLEY OF ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Musa H. AHMED

    2015-11-01

    Full Text Available Land degradation mainly in the form of soil and nutrient depletion is the prominent problem that the Ethiopian agriculture is facing. Due to this, farmers should be aware of this problem and the necessity of implementing conservation measures. Hence, this study assesses farm households’ willingness to participate in soil conservation practice through a Contingent Valuation method in one of the most degraded parts of the country. Double Bounded Dichotomous choice with an Open-ended follow up format was used to elicit the households’ willingness to pay using data collected from randomly selected 140 sample households. Results show that the mean willingness to participate in soil conservation practices was about 25 person days per annum and the total aggregate value of soil conservation was computed to be at 975622.73 person days (24390568.3 Birr. Moreover, the Tobit regression model results indicate that the education level of the household head, initial-bid, income, labour shortage and number of days on holiday and social ceremony were important factors influencing the willingness to participate in soil conservation practices. Hence, to improve the participation level, policy should target on supporting adult education, introducing ways to increase farm income and creating awareness on the loss associated with too many days of social ceremonies.

  3. The Emergence of Homo sapiens in South Asia: The Central Narmada Valley as Witness

    OpenAIRE

    Anek R. Sankhyan

    2013-01-01

    :The emergence of anatomically modern Homo sapiens in South Asia is hotly debated due to a great gap in fossil record. A solitary partial cranium from Hathnora dated around 250 Kya is debated and conveniently interpreted as "evolved" Homo erectus or "archaic" Homo sapiens or Homo heidelbergensis or even Homo indet. Cranial fossils of Pre-Toba or post- Toba anatomically modern Homo sapiens are unknown barring the very late 30 Kya modern human remains from Sri Lanka. The present paper reviews t...

  4. Size-resolved source apportionment of carbonaceous particulate matter in urban and rural sites in central California

    Science.gov (United States)

    Ham, Walter A.; Kleeman, Michael J.

    2011-08-01

    Very little is currently known about the relationship between exposure to different sources of ambient ultrafine particles (PM 0.1) and human health effects. If human health effects are enhanced by PM 0.1's ability to cross cell membranes, then more information is needed describing the sources of ultrafine particles that are deposited in the human respiratory system. The current study presents results for the source apportionment of airborne particulate matter in six size fractions smaller than 1.8 μm particle diameter including ultrafine particles (PM 0.1) in one of the most polluted air basins in the United States. Size-resolved source apportionment results are presented at an urban site and rural site in central California's heavily polluted San Joaquin Valley during the winter and summer months using a molecular marker chemical mass balance (MM-CMB) method. Respiratory deposition calculations for the size-resolved source apportionment results are carried out with the Multiple Path Particle Dosimetry Model ( MPPD v 2.0), including calculations for ultrafine (PM 0.1) source deposition. Diesel engines accounted for the majority of PM 0.1 and PM 1.8 EC at both the urban and rural sampling locations during both summer and winter seasons. Meat cooking accounted for 33-67% and diesel engines accounted for 15-21% of the PM 0.1 OC at Fresno. Meat cooking accounted for 22-26% of the PM 0.1 OC at the rural Westside location, while diesel engines accounted for 8-9%. Wood burning contributions to PM 0.1 OC increased to as much as 12% of PM 0.1 OC during the wintertime. The modest contribution of wood smoke reflects the success of emissions control programs over the past decade. In contrast to PM 0.1, PM 1.8 OC had a higher fraction of unidentified source contributions (68-85%) suggesting that this material is composed of secondary organic aerosol (SOA) or primary organic aerosol (POA) that has been processed by atmospheric chemical reactions. Meat cooking was the largest

  5. The geology of the Upper Ribagorzana and Baliera valleys, Central Pyrenees, Spain

    NARCIS (Netherlands)

    Mey, P.H.W.

    1968-01-01

    In the mapped area there is a well-exposed low-grade metamorphic marine sequence from Ordovician to Lower Carboniferous, unconformably overlain by Permo-Triassic continental deposits. Determinable fossils are rare. The Ordovician consists of a quartzite/shale sequence with one marly limestone interc

  6. Phylogenetic, morphological and pathogenic characterization of Alternaria species associated with fruit rots of blueberry in California

    Science.gov (United States)

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruits. Alternaria spp. isolates were collected from decayed fruits of blueberry in the Central Valley of California during 2012 and 2013. The aims of this study wer...

  7. Water Budgets and Potential Effects of Land- and Water-Use Changes for Carson Valley, Douglas County, Nevada, and Alpine County, California

    Science.gov (United States)

    Maurer, Douglas K.; Berger, David L.

    2006-01-01

    To address concerns over continued growth in Carson Valley, the U.S. Geological Survey, in cooperation with Douglas County, Nevada, began a study in February 2003 to update estimates of water-budget components in Carson Valley. Estimates of water-budget components were updated using annual evapotranspiration (ET) rates, rates of streamflow loss to infiltration and gain from ground-water seepage, and rates of recharge from precipitation determined from data collected in 2003 and 2004 for the study and reported in the literature. Overall water budgets were developed for the area of basin-fill deposits in Carson Valley for water years 1941-70 and 1990-2005. Water years 1941-70 represent conditions prior to increased population growth and ground-water pumping, and the importation of effluent. A ground-water budget was developed for the same area for water years 1990-2005. Estimates of total inflow in the overall water budget ranged from 432,000 to 450,000 acre-feet per year (acre-ft/yr) for water years 1941-70 and from 430,000 to 448,000 for water years 1990-2005. Estimates of total inflow for both periods were fairly similar because variations in streamflow and precipitation were offset by increases in imported effluent. Components of inflow included precipitation on basin-fill deposits of 38,000 acre-ft/yr for both periods, streamflow of the Carson River and tributaries to the valley floor of 372,000 acre-ft/yr for water years 1941-70 and 360,000 acre-ft/yr for water years 1990-2005, ground-water inflow ranging from 22,000 to 40,000 acre-ft/yr for both periods, and imported effluent of 9,800 acre-ft/yr for water years 1990-2005 with none imported for water years 1941-70. Estimates of ground-water inflow from the California portion of Carson Valley averaged about 6,000 acre-ft/yr and ranged from 4,000 to 8,000 acre-ft/yr. These estimates compared well with a previous estimate of ground-water inflow across the State line. Estimates of total outflow in the overall water

  8. Contribution to the knowledge of the Lepidoptera Fauna of the lower Sangro valley in the Abruzzo region of Central Italy

    Directory of Open Access Journals (Sweden)

    Norbert Zahm

    2012-12-01

    Full Text Available We report the results of recording Lepidoptera in the lower Sangro valley during a period of 22 years. The investigations were devoted to Macroheterocera and were carried out in the two regional nature reserves Oasi di Serranella and Lecceta di Torino di Sangro. The listing also includes some Microlepidoptera as non-target species, as well as occasionally observed butterflies. The 401 recorded species are presented in a table indicating both the locality of the records and the observed flight times and periods of activity. Fifteen species are published for the Abruzzo region for the first time; 2 species are new for the Italian peninsula.

  9. Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin Valley Air Quality

    Science.gov (United States)

    Yang, M. M.; Meinardi, S.; Krauter, C.; Blake, D.

    2008-12-01

    The San Joaquin Valley Air Basin in Central California is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). In August 2005, the San Joaquin Valley Air Pollution Control District issued a report identifying dairies as a main source of Volatile Organic Compounds (VOCs) and fine particulate matter in the valley (2). Among these compounds, we have found that ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Three different types of sampling protocols were employed in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates. An assessment of the emissions of these oxygenates in the valley was achieved using data obtained on low altitude flights through the valley and from ground level samples collected thoughout the valley. The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, as much as 20% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that improvement to the valley air quality may be obtained by focusing on instituting new silage containment practices and regulations. 1. Lindberg, J. "Analysis of the San Joaquin Valley 2007 Ozone Plan." State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. Crow, D., executive director/APCO. "Air Pollution Control Officer's Determination of VOC Emisison Factors for Dairies." San Joaquin Valley Air

  10. Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California

    Science.gov (United States)

    Taylor, Ryan D.; Goldfarb, Richard J.; Monecke, Thomas; Fletcher, Ian R.; Cosca, Michael A.; Kelly, Nigel M.

    2015-01-01

    The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, the largest historic gold producer of the North American Cordillera, comprises both steeply dipping east-west (E-W) veins located along lithologic contacts in accreted ca. 300 and 200 Ma oceanic rocks and shallowly dipping north-south (N-S) veins hosted by the Grass Valley granodiorite; the latter have yielded about 70 percent of the 13 million ounces of historic lode gold production in the district. The oceanic host rocks were accreted to the western margin of North America between 200 and 170 Ma, metamorphosed to greenschist and amphibolite facies, and uplifted between 175 and 160 Ma. Large-scale magmatism in the Sierra Nevada occurred between 170-140 Ma and 120-80 Ma, with the Grass Valley granodiorite being emplaced during the older episode of magmatism. Uranium-lead isotopic dating of hydrothermal xenotime yielded the first absolute age of 162±5 Ma for the economically more significant N-S veins. The vein-hosted xenotime, as well as associated monazite, are unequivocally of hydrothermal origin as indicated by textural and chemical characteristics, including grain shape, lack of truncated growth banding, lack of a Eu anomaly, and low U and Th concentrations. Furthermore, the crack-seal texture of the veins, with abundant wallrock slivers, suggests their formation as a result of episodic fluid flow possibly related to reoccurring seismic events, rather than a period of fluid exsolution from an evolving magma. The N-S veins are temporally distinct from a younger 153-151 Ma gold event that was previously reported for the E-W veins. Overlapping U-Pb zircon (159.9±2.2 Ma) and 40Ar/39Ar biotite and hornblende (159.7±0.6 to 161.9±1.4 Ma) ages and geothermobarometric calculations indicate that the Grass Valley granodiorite was emplaced at ca. 160 Ma at elevated temperatures (~800°C) within approximately 3 km of the paleosurface and rapidly cooled to the ambient

  11. Altitudes of the top of model layers for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the altitudes of the tops of 16 model layers simulated in the Death Valley regional ground-water flow system (DVRFS) transient flow...

  12. Map of water table in Solomon River valley, Waconda Lake to Solomon, north-central Kansas, May 1980

    Science.gov (United States)

    Reed, Thomas B.

    1983-01-01

    A map of the water table in the Solomon River valley from Waconda Lake to Solomon presents current (1980) data on water levels in the unconsolidated deposits. The Solomon River, which originates in western Kansas, flows southeastward from Waconda Lake to its confluence with the Smoky Hill River at Solomon. In the study area, its valley is incised into consolidated rocks that are composed mostly of shale and limestone. The unconsolidated deposits in the valley underlie the flood plain and the terrace. The alluvial deposits generally consist of gravel and sand, grading upward to sand and silt, with clay lenses interbedded throughout. Thickness of the deposits may be as much as 70 feet. Ground water in the unconsolidated deposits is a principal source of supply for domestic, stock, and irrigation use. Water-table contours indicate that ground water moves from the alluvial deposits to the stream. Thus, the Solomon River gains in flow through most of the reach. Water-level measurements for this study were made during the spring of 1980, prior to the irrigation season. (USGS)

  13. Spatial ecology of krill, micronekton and top predators in the central California Current: Implications for defining ecologically important areas

    Science.gov (United States)

    Santora, Jarrod A.; Field, John C.; Schroeder, Isaac D.; Sakuma, Keith M.; Wells, Brian K.; Sydeman, William J.

    2012-11-01

    Marine spatial planning and ecosystem models that aim to predict and protect fisheries and wildlife benefit greatly from syntheses of empirical information on physical and biological partitioning of marine ecosystems. Here, we develop spatially-explicit oceanographic and ecological descriptions of the central California Current region. To partition this region, we integrate data from 20 years of shipboard surveys with satellite remote-sensing to characterize local seascapes of ecological significance, focusing on krill, other micronekton taxa, and top predators (seabirds and marine mammals). Specifically, we investigate if micronekton and predator assemblages co-vary spatially with mesoscale oceanographic conditions. The first principal component of environmental and micronekton seascapes indicates significant coupling between physics, primary productivity, and secondary and tertiary marine consumers. Subsequent principal components indicate latitudinal variability in niche-community space due to varying habitat characteristics between Monterey Bay (deep submarine canyon system) and the Gulf of the Farallones (extensive continental shelf), even though both of these sub-regions are located downstream from upwelling centers. Overall, we identified five ecologically important areas based on spatial integration of environmental and biotic features. These areas, characterized by proximity to upwelling centers, shallow pycnoclines, and high chlorophyll-a and krill concentrations, are potential areas of elevated trophic focusing for specific epipelagic and mesopelagic communities. This synthesis will benefit ecosystem-based management approaches for the central California Current, a region long-impacted by anthropogenic factors.

  14. Natural heat storage in a brine-filled solar pond in the Tully Valley of central New York

    Science.gov (United States)

    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).

  15. Economic analysis of feebates to reduce greenhouse gas emissions from light vehicles for California

    OpenAIRE

    McManus, Walter

    2007-01-01

    A growing majority of climate scientists are convinced that unless emissions are reduced, global warming would cause a number of adverse effects throughout the United States. In California, rising temperatures would reduce the snow pack in the Sierra-the state's primary source of water-and lead to less water for irrigating farms in the Central Valley. Global warming would increase the number of extreme heat days and greatly increase the risk of poor air quality across the state. California's ...

  16. Precision overhead irrigation is suitable for several Central Valley crops

    OpenAIRE

    Mitchell, Jeffrey P; Anil Shrestha; Joy Hollingsworth; Daniel Munk; Hembree, Kurt J; Tom A. Turini

    2016-01-01

    Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotto...

  17. Potential Impacts of Climate Change on Groundwater in California

    Science.gov (United States)

    Miller, N. L.

    2011-12-01

    California's water resources are primarily from snowmelt runoff from the Sierra Nevada and Rocky Mountains. Depending on the year, Sierra Nevada snowmelt provides seventy percent of the water resources needed to sustain urban, agricultural, ecological, and other sector needs. With increasing temperatures due to climate change the Sierra Nevada snowmelt is occurring earlier and with decreasing snow cover area. Such change may mimic drought scenarios and dramatically alter water resource availability and management in California. A fundamental requirement for drought water management is knowledge of the total groundwater resources and the rate in which it is depleted. Application of remote sensed Gravity Recovery and Climate Experiment (GRACE) data represents an important new approach toward quantifying these values. The primary uncertainties are the spatial scale required for an accurate GRACE analysis and an insufficient number and frequency of well observations for ground-truth. In this study, an initial quantification of long-term droughts - an analogue for climate change related snowpack reduction - has been performed to illustrate the potential for subsurface storage to limit the adverse impacts of drought and snowpack reduction on water supply in the California. This includes estimates of the impacts of changes in groundwater levels, surface supply, and crop water demands. Analysis of California Central Valley impacts of sustained droughts are based on a series of specified reductions in net surface flows corresponding to historical 30% (below average), 50% (dry), and 70% (critically dry) effective reduction, for periods ranging from 10 to 60 years, and applied to the California Department of Water Resource's California Central Valley Groundwater-Surface Water Simulation Model. The impacts of the droughts are modeled for four different regions in the Central Valley, including the Sacramento Basin, Eastside, the San Joaquin Basin, and the Tulare Basin. Results

  18. Paradigm or Paradox: Can we Attribute Species Changes to Global Climate Change in Light of Decreasing Water Temperatures in Central California?

    OpenAIRE

    Breaker, Laurence, C.; Cailliet, Gregor; Launer, Andrea; Wadsworth, Tom

    2012-01-01

    The main goal of this study was to gather information about historical changes in water temperature and species composition, in order to identify variables that will enable us to predict changes in water temperatures and species abundances in California caused by global climate change. Our primary objectives were to (1) review the existing published and unpublished data sets to refine our understanding of trends in sea surface temperature in central California; (2) review fish and climate dat...

  19. Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.

    Science.gov (United States)

    Rejmanek, Daniel; Vanwormer, Elizabeth; Miller, Melissa A; Mazet, Jonna A K; Nichelason, Amy E; Melli, Ann C; Packham, Andrea E; Jessup, David A; Conrad, Patricia A

    2009-12-01

    Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p=0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p=0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries). PMID:19735983

  20. Rockfall failure mechanisms in Yosemite Valley, California (USA)

    Science.gov (United States)

    Matasci, Battista; Guerin, Antoine; Carrea, Dario; Stock, Greg M.; Jaboyedoff, Michel; Collins, Brian

    2014-05-01

    Rockfall hazard is especially high in Yosemite Valley, with tens of rockfalls inventoried every year. A rockfall on 5 October 2013 from Ahwiyah Point consisted of a volume of 740 cubic meters and occurred within the perimeter of a larger event on 28 March 2009 that released 25'400 cubic meters of rock (Zimmer et al., 2012). In both events (2009 and 2013), the initial rockfall volumes dislodged a second one approximately equivalent in size by impacting the cliff below the source area during the fall. Rock fragments of up to several cubic meters were deposited on the talus slope, damaging a heavily used and recently reconstructed hiking path. We performed extensive mapping of structural features for several cliffs of Yosemite Valley to improve the assessment of the most susceptible rockfall areas. In particular we mapped and characterized the main brittle structures, the exfoliation joints and the failure mechanisms of the past rockfalls. Several failure mechanisms exist in Yosemite including the propagation of brittle structures that may lead to tensile, planar sliding, wedge sliding or toppling failures. Frequently, topographically-parallel exfoliation joints and topographically-oblique discontinuities coexist, resulting in complex failures. We also developed a methodology to examine how the distribution of joints within the cliff faces of Yosemite Valley affects overall stability with respect to the identified failure mechanisms. For these analyses, we used terrestrial laser scanning (TLS) to collect high resolution point clouds of the vertical and overhanging rock faces throughout the Valley. This provided the necessary 3D data to identify the main joint sets, perform spacing and trace length measurements, and calculate volumes of previous and potential rockfalls. We integrated this information with stability calculations to identify the likely failure mechanisms for each area of cliff and to obtain the number of potential failures per square meter of cliff face

  1. Lateral boundary of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the lateral boundary and model domain of the area simulated by the transient ground-water flow model of the Death Valley regional...

  2. False-color composite of Landsat data for the Death Valley regional ground-water flow system project, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The false-color composite image of the Death Valley regional ground-water flow system (DVRFS), an approximately 100,000 square-kilometer region of southern Nevada...

  3. Groundwater discharge area for Diamond Valley, Central Nevada, 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset represents "phreatophyte areas" mapped as part of an analysis of irrigation pumping in Diamond Valley, Nevada published in 1968. The data were...

  4. SIR 2015-5175, Water-level altitude contours of Pahute Mesa-Oasis Valley and surrounding groundwater basins, Nevada and California, version 1.1

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This vector data set contains lines representing water-level altitude contours of Pahute Mesa-Oasis Valley and surrounding groundwater basins in Nevada and...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Information Technology Supports Integration of Satellite Imagery with Irrigation Management in California's Central Valley

    Science.gov (United States)

    Remotely sensed data can potentially be used to develop crop coefficient estimates over large areas and make irrigation scheduling more practical, convenient, and accurate. A demonstration system is being developed under NASA's Terrestrial Observation and Prediction System (TOPS) to automatically r...

  7. Material-property zones used in the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Zones in this data set represent spatially contiguous areas that influence ground-water flow in the Death Valley regional ground-water flow system (DVRFS), an...

  8. Environmental controls on spatial patterns in the long-term persistence of giant kelp in central California

    Science.gov (United States)

    Young, Mary Alida; Cavanaugh, Kyle C.; Bell, Tom W.; Raimondi, Peter T.; Edwards, Christopher A.; Drake, Patrick T.; Erikson, Li H.; Storlazzi, Curt

    2016-01-01

    As marine management is moving towards the practice of protecting static areas, it is 44 important to make sure protected areas capture and protect persistent populations. Rocky reefs in 45 many temperate areas worldwide serve as habitat for canopy forming macroalgae and these 46 structure forming species of kelps (order Laminariales) often serve as important habitat for a great 47 diversity of species. Macrocystis pyrifera is the most common canopy forming kelp species found 48 along the coast of California but the distribution and abundance of M. pyrifera varies in space and 49 time. The purpose of this study is to determine what environmental parameters are correlated with 50 the spatial and temporal persistence of M. pyrifera along the central coast of California and how 51 well those environmental parameters can be used to predict areas where M. pyrifera is more likely 52 to persist. Nine environmental variables considered in this study included depth of the seafloor, 53 structure of the rocky reef, proportion of rocky reef, size of kelp patch, biomass of kelp within a 54 patch, distance from the edge of a kelp patch, sea surface temperature, wave orbital velocities, and 55 population connectivity of individual kelp patches. Using a generalized linear mixed effects model 56 (GLMM), the persistence of M. pyrifera was significantly associated with seven of the nine 57 variables considered: depth, complexity of the rocky reef, proportion of rock, patch biomass, 58 distance from the edge of a patch, population connectivity, and wave-orbital velocities. These 59 seven environmental variables were then used to predict the persistence of kelp across the central 60 coast and these predictions were compared to a reserved dataset of M. pyrifera persistence, which 61 was not used in the creation of the GLMM. The environmental variables were shown to accurately 62 predict the persistence of M. pyrifera within the central coast of California (r = 0.71, P<0.001). 63 Because

  9. Aerial photographic interpretation of lineaments and faults in late Cenozoic deposits in the eastern parts of the Saline Valley 1:100, 000 quadrangle, Nevada and California, and the Darwin Hills 1:100, 000 quadrangle, California

    International Nuclear Information System (INIS)

    Faults and fault-related lineaments in Quaternary and late Tertiary deposits in the southern part of the Walker Lane are potentially active and form patterns that are anomalous compared to those in most other areas of the Great Basin. Two maps at a scale of 1:100,000 summarize information about lineaments and faults in the area around and southwest of the Death Valley-Furnace Creek fault system based on extensive aerial-photo interpretation, limited field interpretation, limited field investigations, and published geologic maps. There are three major fault zones and two principal faults in the Saline Valley and Darwin Hills 1:100,000 quadrangles. (1) The Death Valley-Furnace Creek fault system and (2) the Hunter Mountain fault zone are northwest-trending right-lateral strike-slip fault zones. (3) The Panamint Valley fault zone and associated Towne Pass and Emigrant faults are north-trending normal faults. The intersection of the Hunter Mountain and Panamint Valley fault zones is marked by a large complex of faults and lineaments on the floor of Panamint Valley. Additional major faults include (4) the north-northwest-trending Ash Hill fault on the west side of Panamint Valley, and (5) the north-trending range-front Tin Mountain fault on the west side of the northern Cottonwood Mountains. The most active faults at present include those along the Death Valley-Furnace Creek fault system, the Tin Mountain fault, the northwest and southeast ends of the Hunter Mountain fault zone, the Ash Hill fault, and the fault bounding the west side of the Panamint Range south of Hall Canyon. Several large Quaternary landslides on the west sides of the Cottonwood Mountains and the Panamint Range apparently reflect slope instability due chiefly to rapid uplift of these ranges. 16 refs

  10. Reproductive dynamics of Pacific sanddab, Citharichthys sordidus, off the central coast of California

    Science.gov (United States)

    Lefebvre, Lyndsey S.; Payne, Amber M.; Field, John C.

    2016-01-01

    Female Pacific sanddab were collected from the Monterey Bay, California to describe their reproductive strategy and annual reproductive cycle, as well as to estimate length at maturity, fecundity, spawning fraction (SF), and spawning interval (SI). Captive females were held to examine degradation of spawning markers and confirmed the biological spawning capabilities of the species. The reproductive season extended from May through January, as determined through macroscopic and histological examination of ovaries. Oocyte development was asynchronous, and an indeterminate fecundity pattern was displayed. Absolute and relative batch fecundity values were variable (means = 6663 eggs and 54 eggs g- 1 somatic weight, respectively) and significantly related to maternal length. During the period of highest reproductive activity, SF ranged from 0.42 to 0.98, suggesting some females were spawning on a daily basis. Monthly SF and SI were related to length, with smaller females having a truncated season and lower SF compared to larger females. Lengths at 50% (119 mm) and 95% (149 mm) maturity showed a downward shift relative to the 1940s, though the magnitude and cause of this shift remain unknown. This study highlights the importance of considering demographic shifts and size-related dynamics when modeling a stock's reproductive potential.

  11. Digital Elevation Model (DEM) file of topographic elevations for the Death Valley region of southern Nevada and southeastern California processed from US Geological Survey 1-degree Digital Elevation Model data files

    International Nuclear Information System (INIS)

    Elevation data have been compiled into a digital data base for an ∼100,000-km2 area of the southern Great Basin, the Death Valley region of southern Nevada, and SE Calif., located between lat 35 degree N, long 115 degree W, and lat 38 degree N, long 118 degree W. This region includes the Nevada Test Site, Yucca Mountain, and adjacent parts of southern Nevada and eastern California and encompasses the Death Valley regional ground-water system. Because digital maps are often useful for applications other than that for which they were originally intended, and because the area corresponds to a region under continuing investigation by several groups, these digital files are being released by USGS

  12. Inter-seasonal variability in baseflow recession rates: The role of aquifer antecedent storage in central California watersheds

    Science.gov (United States)

    Bart, Ryan; Hope, Allen

    2014-11-01

    Baseflow recession rates vary inter-seasonally in many watersheds. This variability is generally associated with changes in evapotranspiration; however, an additional and less studied control over inter-seasonal baseflow recession rates is the effect of aquifer antecedent storage. Understanding the role of aquifer antecedent storage on baseflow recession rates is crucial for Mediterranean-climate regions, where seasonal asynchronicity of precipitation and energy levels produces large inter-seasonal differences in aquifer storage. The primary objective of this study was to elucidate the relation between aquifer antecedent storage and baseflow recession rates in four central California watersheds using antecedent streamflow as a surrogate for watershed storage. In addition, a parsimonious storage-discharge model consisting of two nonlinear stores in parallel was developed as a heuristic tool for interpreting the empirical results and providing insight into how inter-seasonal changes in aquifer antecedent storage may affect baseflow recession rates. Antecedent streamflow cumulated from the beginning of the wateryear was found to be the strongest predictor of baseflow recession rates, indicating that inter-seasonal differences in aquifer storage are a key control on baseflow recession rates in California watersheds. Baseflow recession rates and antecedent streamflow exhibited a negative power-law relation, with baseflow recession rates decreasing by up to two orders of magnitude as antecedent streamflow levels increased. Inference based on the storage-discharge model indicated that the dominant source of recession flow shifted from small, rapid response aquifers at the beginning of the wet season to large, seasonal aquifers as the wet season progressed. Aquifer antecedent storage in California watersheds should be accounted for along with evapotranspiration when characterizing baseflow recession rates.

  13. Geometry of Valley Growth

    CERN Document Server

    Petroff, Alexander P; Abrams, Daniel M; Lobkovsky, Alexander E; Kudrolli, Arshad; Rothman, Daniel H

    2011-01-01

    Although amphitheater-shaped valley heads can be cut by groundwater flows emerging from springs, recent geological evidence suggests that other processes may also produce similar features, thus confounding the interpretations of such valley heads on Earth and Mars. To better understand the origin of this topographic form we combine field observations, laboratory experiments, analysis of a high-resolution topographic map, and mathematical theory to quantitatively characterize a class of physical phenomena that produce amphitheater-shaped heads. The resulting geometric growth equation accurately predicts the shape of decimeter-wide channels in laboratory experiments, 100-meter wide valleys in Florida and Idaho, and kilometer wide valleys on Mars. We find that whenever the processes shaping a landscape favor the growth of sharply protruding features, channels develop amphitheater-shaped heads with an aspect ratio of pi.

  14. Impacts of Photovoltaic Power Plant Sitings and Distributed Solar Panels on Meteorology and Air Quality in Central California

    Science.gov (United States)

    Bastien, L. A.; Jin, L.; Brown, N. J.

    2012-12-01

    California's electric utility companies are required to use renewable energy to produce 20% of their power by 2010 and 33% by 2020. A main source of the power will be solar energy because photovoltaic technologies have advanced so much that large scale installations are being built and will be built in the future with even greater capacity. Rather than being a large emission source, these plants affect the ambient environment through albedo changes and by emission reductions associated with not burning fossil fuels to generate the same amount of electricity. Like conventional power plants, their impact on local meteorology and air quality depends on the specific technology, ambient atmospheric conditions, and the spatial location of the plant. Also, as solar panels on commercial and residential rooftops become even more common, the effect of distributed photovoltaic panels on meteorology and air quality is likely to become significant. In this study, we use the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model at high resolution of 4 km x 4 km over several 5-day high-ozone episodes of the summer 2000 to assess the impact of photovoltaic panels on meteorology and air quality in Central California. We investigate the effect of locating a 1.0 Giga watt solar plant in different locations and the effect of distributed rooftop photovoltaic panels in major Californian cities, with a focus on peak and 8-hour average ozone and 24-hour average PM2.5.

  15. Crossroads gas field, Sacramento Valley, California: an exploration case history

    Energy Technology Data Exchange (ETDEWEB)

    McCrae, R.O.

    1977-01-01

    The Crossroads gas field is located in the Sacramento Valley, 17 miles northwest of the city of Sacramento. The discovery well, Socal No. 1 Amstar, was completed in April 1976 from 3 sand zones, for a total productive potential of 7,200 Mcfd. The field is still in the development phase with 4 wells, all potentially productive, completed to date. The exploratory program was initiated through regional subsurface mapping of available well control and a prospective trend was outlined based on stratigraphic trap potential in Winters sand zones. The stratigraphic interpretation relying on well data and aided by one new seismic reconnaissance line indicated the probability of the pinchout of lenticular sands updip eastward into a pro-delta slope/shelf shale facies. Land acquisition was initiated with the verification of the exploratory model and continued throughout the exploratory phase of the program.

  16. A Multi-Isotope (B, Sr, O, H, C) and Age Dating (3H-3He, 14C) Study of Ground Water From Salinas Valley, California: Hydrochemistry, Dynamics, and Contamination Processes

    Energy Technology Data Exchange (ETDEWEB)

    Vengosh, A; Gill, J; Davisson, M L; Hudson, B G

    2001-08-01

    The chemical and isotopic ({sup 11}B/{sup 10}B, {sup 87}Sr/{sup 86}Sr, {sup 18}O/{sup 16}O, {sup 2}H/H, {sup 13}C/{sup 12}C, {sup 14}C, {sup 3}He/{sup 3}H) compositions of groundwater from the upper aquifer system of the Salinas Valley in coastal central California were investigated in order to delineate the origin and processes of groundwater contamination in this complex system. The Salinas Valley has a relatively deep, confined ''400-foot'' aquifer, overlain by a ''180-foot'' aquifer, and a shallower perched aquifer, all made up of alluvial sand, gravel, and clay deposits. Groundwater from the aquifers have different {sup 14}C ages; fossil ({sup 14}C = 21.3 pmc) for the 400-foot, and modern ({sup 14}C = 72.2 to 98.2 pmc) for the 180-foot. Fresh groundwater in all aquifers is recharged naturally and artificially and through the Salinas River. The two modes of recharge can be distinguished chemically. We identified several different saline components with distinguishable chemical and isotopic fingerprints. (1) Salt-water intrusion in the northern basin has Cl concentrations up to 1700 mg/l, a Na/Cl ratio seawater, {delta}{sup 11}B between +17 and +38 per mil, and {sup 87}Sr/{sup 86}Sr between 0.7088 and 0.7096. Excess dissolved Ca, relative to the expected concentration for simple dilution of seawater, correlates with {sup 87}Sr/{sup 86}Sr ratios, suggesting base exchange reaction with clay minerals. (2) Agriculture return flow is high in NO{sub 3} and SO{sub 4}, with a {sup 87}Sr/{sup 86}Sr = 0.7082, {delta}{sup 11}B = 19 per mil; and {delta}{sup 13}C between -23 and -17 per mil. The {sup 3}H-{sup 3}He ages (5-17 years) and {sup 14}C data suggest vertical infiltration rates of irrigation water of 3 to 10 m/yr. (3) Non-marine saline water in the southern part of the valley has high TDS up to 3800 mg/l, high SO{sub 4}, Na/Cl ratio >1, {delta}{sup 11}B between +24 and +30 per

  17. Slip budget and potential for a M7 earthquake in central California

    Science.gov (United States)

    Harris, Ruth A.; Archuleta, Ralph J.

    1988-10-01

    The slip rate budget of the San Andreas fault (SAF) in central California, which is approximately 33 mm/yr, is accounted for by a change in the slip release mechanism along the fault. In the NW section of the fault, between Bear Valley and Monarch Peak, creep apparently accounts for the slip budget with the seismicity contributing negligibly. The section at Parkfield marks the transition from a creeping to a locked fault trace. Since the M8 1857 earthquake five M6 earthquakes have occurred but have not completely accounted for the slip budget. Southeast of Parkfield, the SAF has been locked since 1857. From Cholame to Bitterwater Valley this section now lags the deep slip by the amount of slip released in 1857; consequently faulting in this section could occur at the time of the next Parkfield earthquake. If this earthquake releases the slip deficit accumulated in the transition zone and in the locked zone, the earthquake will have a moment-magnitude M7.2.

  18. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California

    Science.gov (United States)

    Rejmanek, Daniel; Miller, Melissa A.; Grigg, Michael E.; Crosbie, Paul R.; Conrad, Patricia A.

    2016-01-01

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums. PMID:20226596

  19. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California.

    Science.gov (United States)

    Rejmanek, Daniel; Miller, Melissa A; Grigg, Michael E; Crosbie, Paul R; Conrad, Patricia A

    2010-05-28

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums. PMID:20226596

  20. Refurbished extensometer sites improve the quality and frequency of aquifer-system compaction and groundwater-level measurements, San Joaquin Valley, California, USA

    Science.gov (United States)

    Sneed, M.; Brandt, J.; Solt, M.

    2012-12-01

    Extensive groundwater withdrawal from unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and land subsidence locally exceeding 8 meters (m) between 1926 and 1970. To identify the extent of subsidence, a network of 31 extensometers was installed in the 1960s. Importation of surface water in the early 1970s resulted in decreased groundwater pumping, a steady water-level recovery, and a reduced rate of compaction; consequently, data collection was sharply reduced. However, reduced surface-water availability during 1976-77, 1987-92, and 2007-09 caused increased groundwater pumping, lowered water levels, and renewed compaction. The resulting land subsidence has reduced freeboard and flow capacity of the Delta-Mendota Canal (DMC), the California Aqueduct (AQ), and other canals. Four deep (>300-m) cable-type extensometers from the old network, located along the DMC and AQ, were refurbished to identify existing and future subsidence, and to improve the quality and frequency of compaction measurements. Measurement quality was improved at three of these sites by replacing the existing reference tables, which sit atop concrete pads, with new reference tables cemented in 5.5-m boreholes and decoupled from the concrete pads to minimize the measurement of near-surface deformation. A new reference table could not be constructed at the fourth site due to restrictive drill-rig access. Insulated metal shelters were constructed to protect the equipment against environmental exposure at all sites. The frequencies of compaction and water-level measurements at the extensometer sites were improved by instrumenting each with a linear potentiometer and one or more submersible pressure transducers, respectively. An analog dial gauge was installed on each extensometer to provide data continuity in cases of electronic data interruption and to provide verification of potentiometer data. Aquifer-system compaction data from all four sites show

  1. An 11 000-year-long record of fire and vegetation history at Beaver Lake, Oregon, central Willamette Valley

    Science.gov (United States)

    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.

  2. Precision overhead irrigation is suitable for several Central Valley crops

    Directory of Open Access Journals (Sweden)

    Jeffrey P. Mitchell

    2016-04-01

    Full Text Available Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotton, tomato, onion and broccoli as an alternative to furrow and drip irrigation. With the exception of tomato, equal or increased yields were achieved with overhead irrigation. Many variables are involved in the choice of an irrigation system, but our results suggest that, with more research to support best management practices, overhead irrigation may be useful to a wider set of California farmers than currently use it.

  3. Diversity of pulsed field gel electrophoresis pulsotypes, serovars and antibiotic resistance among Salmonella isolates from wild amphibians and reptiles in the California central coast

    Science.gov (United States)

    A survey of cold-blooded vertebrates and associated surface waters in a produce-growing region on the Central California Coast was done between May and September, 2011 to determine the diversity of Salmonella strains in these habitats and individuals. Samples from 460 amphibians and reptiles and 119...

  4. Structural, metamorphic, and geochronologic constraints on the origin of the Condrey Mountain Schist, north central Klamath Mountains, northern California

    Energy Technology Data Exchange (ETDEWEB)

    Helper, M.A.

    1985-01-01

    The Condrey Mountain Schist (CMS) occupies a window through Late Triassic amphibolite facies melange in the north central Klamath Mountains in northern California and southwest Oregon. Transitional blueschist-greenschist facies assemblages are widespread in mafic schists in the structurally lowest levels of the window; structurally higher CMS near the window margins contains medium- to high-pressure greenschist facies parageneses. An /sup 40/Ar//sup 39/Ar crossite age indicates a late Middle Jurassic age of metamorphism. Pressure-temperature estimates for the overlying CMS greenschists suggest temperatures similar to those in the central part of the window, but at slightly lower pressures. Thrusting of the overlying amphibolites at 150-156 MA occurred while the amphibolites were above about 500C. Stretching lineations indicate a movement vector of about N45W. Comparisons of the sequence and timing of metamorphic and structural events, radiometric ages, and movement directions during thrusting indicate the CMS does not represent an inlier of Kalamath Western Jurassic Belt flysch but is instead an older, isolated thrust plate. Similarities with the age of metamorphism and plutonism in the overlying amphibolites suggest the two plates may be remnants of the same Middle Jurassic paired metamorphic belt.

  5. Shipboard measurements of gaseous elemental mercury along the coast of Central and Southern California

    Science.gov (United States)

    Weiss-Penzias, P. S.; Williams, E. J.; Lerner, B. M.; Bates, T. S.; Gaston, C.; Prather, K.; Vlasenko, A.; Li, S. M.

    2013-01-01

    Gaseous elemental mercury (GEM) in the atmosphere was measured during an oceanographic cruise in coastal waters between San Diego and San Francisco, California during the CalNex 2010 campaign. The goal of the measurements was to quantify GEM in the various environments that the ship encountered, from urban outflow, the Port of Long Beach and associated shipping lanes, coastal waters affected by upwelling, the San Francisco Bay, and the Sacramento ship channel. Mean GEM for the whole cruise was 1.41 ± 0.20 ng m-3, indicating that background concentrations were predominantly observed. The ship's position was most often in waters off the coast of Los Angeles (74% of time with latitude 0.05) higher than the whole cruise mean. South of 34.3°N, GEM was observed to vary diurnally and as a function of wind direction, displaying significantly higher concentrations at night and in the morning associated with general transport from the land to the sea. GEM and CO concentrations were positively correlated with a slope of 0.0011 ng m-3 ppbv-1 (1.23 × 10-7 mol mol-1) during periods identified as "Los Angeles urban outflow", which given the inventoried CO emissions for the region, suggests a larger source of GEM than is accounted for by the inventory. The timing of the diel maximum in GEM (9:00 local time) was intermediate between the maxima of CO and NO2 (6:00) and that of NO and SO2 (10:00-12:00), suggesting that a mixture of urban and industrial sources were contributing to GEM. There was no observable postsunrise dip in GEM concentrations due to reaction with atomic chlorine in the polluted coastal atmosphere. On three occasions, significantly higher GEM concentrations were observed while in the Port of Long Beach (~ 7 ng m-3), and analyses of wind directions, ratios of GEM with other copollutants, and the composition of single particles, suggest that these plumes originated from the local waste incinerator in the Port area. A plume encounter from a large cargo ship

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

    Science.gov (United States)

    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 ...

  7. 77 FR 64544 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    2012-10-22

    ... Dorado Irrigation District Lower Tule River Irrigation District City of Roseville East Bay Municipal... Irrigation District Porterville Irrigation District To meet the requirements of the Central Valley Project... available cost-effective technology and best management practices.'' These criteria state that all...

  8. 76 FR 12756 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    2011-03-08

    ... available for review: Truckee-Carson Irrigation District. Goleta Water District. Delano-Earlimart Irrigation District. Feather Irrigation District. To meet the requirements of the Central Valley Project Improvement... criteria state that all parties (Contractors) that contract with Reclamation for water supplies...

  9. 76 FR 58840 - Central Valley Project Improvement Act; Refuge Water Management Plans

    Science.gov (United States)

    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...) 978-5281 (TDD 978-5608). SUPPLEMENTARY INFORMATION: The following Refuge Water Management Plans...

  10. 77 FR 12526 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-03-01

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Mojave Desert Quality Management District AGENCY: Environmental Protection Agency... Quality Management District (AVAQMD) and Mojave Desert Air Quality Management District (MDAQMD) portion...

  11. 78 FR 49992 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-08-16

    ... Quality Management District (AVAQMD) and Ventura County Air Pollution Control District (VCAPCD) portions... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Ventura County Air Pollution Control District AGENCY: Environmental Protection...

  12. 77 FR 745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-01-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Correction In rule document 2011-33660 appearing on...

  13. Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada

    Directory of Open Access Journals (Sweden)

    J. M. Creamean

    2015-01-01

    Full Text Available Aerosols that serve as cloud condensation nuclei (CCN and ice nuclei (IN have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009–2011, the variability and associated impacts of different aerosol sources on precipitation were investigated in the California Sierra Nevada using an aerosol time-of-flight mass spectrometer for precipitation chemistry, S-band profiling radar for precipitation classification, remote sensing measurements of cloud properties, and surface meteorological measurements. The composition of insoluble residues in precipitation samples collected at a surface site contained mostly local biomass burning and long-range transported dust and biological particles (2009, local sources of biomass burning and pollution (2010, and long-range transport from distant sources (2011. Although differences in the sources were observed from year-to-year, the most consistent source of dust and biological residues were associated with storms consisting of deep convective cloud systems with significant quantities of precipitation initiated in the ice phase. Further, biological residues were dominant (up to 40% during storms with relatively warm cloud temperatures (up to −15 °C, supporting the important role bioparticles can play as ice nucleating particles. On the other hand, lower percentages of residues from local biomass burning and pollution were observed over the three winter seasons (on average 31 and 9%, respectively. When precipitation quantities were relatively low, these residues most likely served as CCN, forming smaller more numerous cloud droplets at the base of shallow cloud systems, and resulting in less efficient riming processes. The correlation between the source of aerosols within clouds and precipitation type and quantity will be further probed in models to

  14. Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada

    Science.gov (United States)

    Creamean, J. M.; Ault, A. P.; White, A. B.; Neiman, P. J.; Ralph, F. M.; Minnis, P.; Prather, K. A.

    2015-01-01

    Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009-2011), the variability and associated impacts of different aerosol sources on precipitation were investigated in the California Sierra Nevada using an aerosol time-of-flight mass spectrometer for precipitation chemistry, S-band profiling radar for precipitation classification, remote sensing measurements of cloud properties, and surface meteorological measurements. The composition of insoluble residues in precipitation samples collected at a surface site contained mostly local biomass burning and long-range transported dust and biological particles (2009), local sources of biomass burning and pollution (2010), and long-range transport from distant sources (2011). Although differences in the sources were observed from year-to-year, the most consistent source of dust and biological residues were associated with storms consisting of deep convective cloud systems with significant quantities of precipitation initiated in the ice phase. Further, biological residues were dominant (up to 40%) during storms with relatively warm cloud temperatures (up to -15 °C), supporting the important role bioparticles can play as ice nucleating particles. On the other hand, lower percentages of residues from local biomass burning and pollution were observed over the three winter seasons (on average 31 and 9%, respectively). When precipitation quantities were relatively low, these residues most likely served as CCN, forming smaller more numerous cloud droplets at the base of shallow cloud systems, and resulting in less efficient riming processes. The correlation between the source of aerosols within clouds and precipitation type and quantity will be further probed in models to understand the

  15. Irrigated Agricultural Lands and Other Anthropogenic Land Disturbance in the Diamond Valley Flow System, Central Nevada, 2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central...

  16. Summer Mean Enhanced Vegetation Index for the Diamond Valley Flow System Groundwater Discharge Area, Central Nevada, 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central...

  17. A Seasonal Perspective on Regional Air Quality in CentralCalifornia - Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Harley, Robert A.; Brown, Nancy J.; Tonse, Shaheen R.; Jin, Ling

    2006-12-01

    Central California spans a wide variety of urban, agricultural, and natural terrain, including the San Francisco Bay area, the Central Valley, and the Sierra Nevada Mountains. Population within this region is growing rapidly, and there are persistent, serious air pollution problems including fine particulate matter (PM{sub 2.5}) and ozone. Summertime photochemical air pollution is the focus of the present study, which represents a first phase in the development and application of a modeling capability to assess formation and transport of ozone and its precursors within Central California over an entire summer season. This contrasts with past studies that have examined pollutant dynamics for a few selected high-ozone episodes each lasting 3-5 days. The Community Multiscale Air Quality model (CMAQ) has been applied to predict air pollutant formation and transport in Central California for a 15-day period beginning on July 24, 2000. This period includes a 5-day intensive operating period (July 29 to August 2) from the Central California Ozone Study (CCOS). Day-specific meteorological conditions were modeled by research collaborators at NOAA using a mesoscale meteorological model (MM5). Pollutant emissions within the study domain were based on CARB emission inventory estimates, with additional efforts conducted as part of this research to capture relevant emissions variability including (1) temperature and sunlight-driven changes in biogenic VOC, (2) weekday/weekend and diurnal differences in light-duty (LD) and heavy-duty (HD) motor vehicle emissions, (3) effects of day-specific meteorological conditions on plume rise from point sources such as power plants. We also studied the effects of using cleaner pollutant inflow boundary conditions, lower than indicated during CCOS aircraft flights over the Pacific Ocean, but supported by other surface, ship-based, balloon and aircraft sampling studies along the west coast. Model predictions were compared with measured

  18. Seasonal variations in plant nitrogen relations and photosynthesis along a grassland to shrubland gradient in Owens Valley, California

    OpenAIRE

    Goedhart, C. M.; Pataki, D. E.; Billings, S.A.

    2010-01-01

    Community composition in semi-arid ecosystems has largely been explained by water availability; however, nitrogen is a common limiting nutrient, and may be an important control on plant function and carbon uptake. We investigated nitrogen relations and photosynthesis of several dominant species at shallow groundwater sites in Owens Valley, California. We measured soil nitrogen (N) availability, leaf N and isotopes, water isotopes, and gas exchange of dominant shrub species Atriplex torreyi an...

  19. 75 FR 30393 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-06-01

    ... documents are available via the Internet on NCEA's home page under the Recent Additions and Publications... Central Appalachian Streams'' are available primarily via the Internet on the National Center for... included as part of the comment that is placed in the public docket and made available on the Internet....

  20. Monthly urban (municipal and industrial use) pumpage for the Central Valley Hydrologic Model (CVHM) by Water Balance Subregion (WBS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly urban (municipal and industrial use) pumpage for the Central Valley Hydrologic Model (CVHM) by Water Balance Subregion...

  1. Population dynamics of insect vectors of Xylella fastidiosa in almond nurseries in the San Joaquin Valley of California: An assessment of plant vulnerability to almond leaf scorch disease.

    Science.gov (United States)

    Almond leaf scorch (ALS) is caused by the xylem-limited bacterium Xylella fastidiosa, which also infects ~145 other plant species in California. The pathogen is transmitted by xylem-fluid feeding insects including sharpshooters and spittlebugs. Within almond orchards tree-to-tree spread of the pat...

  2. Bottom-up, decision support system development : a wetland salinity management application in California's San Joaquin Valley

    OpenAIRE

    Quinn, Nigel W. T.

    2006-01-01

    Seasonally managed wetlands in the Grasslands Basin of California's San Joaquin Valley provide food and shelter for migratory wildfowl during winter months and sport for waterfowl hunters during the annual duck season. Surface water supply to these wetland contain salt which, when drained to the San Joaquin River during the annual drawdown period, negatively impacts downstream agricultural riparian water diverters. Recent environmental regulation, limiting discharges salinity to the San ...

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

    Data.gov (United States)

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

  4. Use of GIS maps in assessing the role of alfalfa in the epidemiology of xylellae diseases in California

    Science.gov (United States)

    Grape and almond are planted throughout much of California. Both crops are susceptible to diseases caused by Xylella fastidiosa. Within California’s Central Valley, the green sharpshooter (Draeculacephala minerva) is a key vector. This insect is often found in large numbers in cultivated alfalfa ...

  5. A conceptual ground-water-quality monitoring network for San Fernando Valley, California

    Science.gov (United States)

    Setmire, J.G.

    1985-01-01

    A conceptual groundwater-quality monitoring network was developed for San Fernando Valley to provide the California State Water Resources Control Board with an integrated, basinwide control system to monitor the quality of groundwater. The geology, occurrence and movement of groundwater, land use, background water quality, and potential sources of pollution were described and then considered in designing the conceptual monitoring network. The network was designed to monitor major known and potential point and nonpoint sources of groundwater contamination over time. The network is composed of 291 sites where wells are needed to define the groundwater quality. The ideal network includes four specific-purpose networks to monitor (1) ambient water quality, (2) nonpoint sources of pollution, (3) point sources of pollution, and (4) line sources of pollution. (USGS)

  6. Migration, nostalgia and the building of a food imaginary: Mexican migrants at "La Pulga" market in San Joaquin Valley, California

    OpenAIRE

    José A. VÁZQUEZ-MEDINA; Medina, F. Xavier

    2015-01-01

    In the context of transnational migration, ethnic markets function as segmented spaces where migrants as a group may be observed on many levels. Provisioning in the market (as much by immigrants as by natives or long-term residents) as well as the consumption of prepared food in situ compel a multiplicity of social interactions that facilitate knowledge and social relations, including recipes, memories, nostalgia, circulation of products and culinary techniques. In addition, a market can acqu...

  7. Artificial recharge in the northern part of Chino ground-water basin, upper Santa Ana Valley, California

    Science.gov (United States)

    Koehler, J.H.

    1983-01-01

    This study was made to help management design and implement a recharge-recapture system for State Water Project water in Chino Basin. Nine test holes were drilled in the study area. Analyses of data from these test holes and drillers ' logs of water wells indicate the presence of clay deposits. The clay deposits cannot be correlated between holes which indicates that they are in the form of discontinuous beds or lenses. The existence and location of two ground-water barriers (Barrier ' J ' and Red Hill Barrier) have been postulated in previous reports. Water-level data indicate that Barrier ' J ' is probably not effectively stopping the movement of ground water. Data are insufficient to determine the effectiveness of the Red Hill barrier. Five existing recharge facilities in the study area were previously constructed to control floodflow. Infiltration tests were conducted at three of the facilities, and results of these tests indicate infiltration rates of 2.6 feet per day at Day Creek, 2.0 feet per day at East Etiwanda, and 1.3 feet per day at San Sevaine. A total of about 9,000 acre-feet of State Water Project water was recharged between June 1980 and July 1981. Rising water levels in wells indicate that recharge water is percolating down to the water table. (USGS)

  8. Baseline sensitivity to fluopyram and fungicide resistance phenotypes of botrytis cinerea populations from table grapes in california

    Science.gov (United States)

    Gray mold caused by Botrytis cinerea is a major postharvest disease of table grapes grown in the Central Valley of California. Understanding fungicide-resistant phenotypes of B. cinerea is important to the development of pre-harvest fungicide programs for control of postharvest gray mold. Baseline s...

  9. Spatial Patterns of Airborne Pesticides in the Alpine Habitat of a Declining California Amphibian, The Mountain Yellow-Legged Frog

    Science.gov (United States)

    The mountain yellow-legged frog complex (Rana muscosa complex) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distributions and conce...

  10. Opinions from teachers in the Fresno area of Central California regarding the influence of mobile technology on their students’ learning

    Directory of Open Access Journals (Sweden)

    Navaridas, Fermín

    2013-10-01

    Full Text Available This paper presents the most relevant results of a study in which opinions of the teachers in the area of Fresno (Central California, USA about the effects of the integration of mobile devices into the teaching-learning process. Among other objectives, this study has tried to analyze the influence of mobile learning over three very important learning factors: affective-emotional (motivation, ethic-social (social skills and the cognitive one (cognitive skills. In order to carry out this study, a descriptive methodological approach was adopted, using the survey technique as the most adequate method to collect teachers´ opinions in a relatively fast and precise way. Obtained results show a widespread agreement among teachers about the pedagogical potential of mobile devices as a tool to improve learning quality. In general terms, conclusions suggest an improvement in the students’ interest on educational tasks, an increase during study activities, a better collaborative work, as well as an improvement of creativity and information acquisition.

  11. Correlation and analysis of Miocene paleochannels in the central Sierra Nevada, California, as displayed by the Stanislaus Group

    Science.gov (United States)

    Jones, S.; Pluhar, C. J.; Farner, M. J.; Deino, A. L.

    2013-12-01

    The proposed Neogene uplift of the Sierra Nevada has been debated for several decades. Although multiple lines of evidence indicate substantial uplift of the Sierran crest over the last ten million years, recent isotopic and paleobotanical methods have called the validity of these calculations into question. Our study focuses on the discontinuous units of the Miocene Stanislaus Group: Table Mountain Formation lavas, Dardenelles Formation lavas, and Eureka Valley Tuff (EVT) lava and tuffs. These units are significant because they have been used as a tilt indicator to calculate the uplift of the Sierra Nevada crest since their emplacement, 9.0-10.2 million years ago. Our research increased the quantity of primary data, which will be used to develop and verify a digitally-derived model of the paleodrainage systems of the ancient Sierra Nevada. The localities, Dorrington, Pikes Peak, Rancheria Mountain, Three Chimneys, and Sonora Pass are significant because they may represent the few remaining Table Mountain Formation (trachyandesite) outcrops of previously unmapped paleodrainage channels. To test this hypothesis, geochemical and paleomagnetic data were used to correlate the localities and thereby reconstruct the paleochannels. Outcrops near Dorrington, California contain biotite, display eutaxitic textures and are characterized by a reverse polarity indistinguishable from the Tollhouse Flat Member of the EVT. Previously mapped as Table Mountain Latite, we reclassify these units as Tollhouse Flat Member and eliminate the hypothesis that the units were once part of a potentially lava-back-flooded tributary of the paleo-Stanislaus River. The high potassium, columnar jointed lava at Pikes Peak, exhibits normal polarity; it is plausibly part of the Stanislaus Group and may be correlated to flows along the main 'cataract channel' of the Stanislaus Group. Results from Rancheria Mountain verify the presence of Stanislaus Group lavas and the EVT, previously mapped by Huber et

  12. CCALBATC - bathymetric contours for the central California region between Point Arena and Point Sur.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — CCALBATC consists of bathymetric contours at 10-m and 50-m intervals for the area offshore of central California between Point Arena to the north and Point Sur to...

  13. SRTM Stereo Pair with Landsat Overlay: Los Angeles to San Joaquin Valley, California

    Science.gov (United States)

    2000-01-01

    California's topography poses challenges for road builders. Northwest of Los Angeles, deformation of Earth's crust along the Pacific-North American crustal plate boundary has made transportation difficult. Direct connection between metropolitan Los Angeles (image lower left) and California's Central Valley (image top center) through the rugged terrain seen on the left side of this image was long avoided in favor of longer, but easier paths. However, over the last century, three generations of roads have traversed this terrain. The first was 'The Ridge Route', a two-lane road, built in 1915, which followed long winding ridge lines that included 697curves. The second, built in 1933, was to become four-lane U.S. Highway 99. It generally followed widened canyon bottoms. The third is the current eight lane Interstate 5 freeway, built in the 1960s, which is generally notched into hillsides, but also includes a stretch of several miles where the two directions of travel are widely separated and driving is 'on the left', a rarity in the United States. Such an unusual highway configuration was necessary in order to optimize the road grades for uphill and downhill traffic in this topographically challenging setting.This stereoscopic image was generated by draping a Landsat satellite image over a preliminary SRTM elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive

  14. A Fully-Integrated Framework for Terrestrial Water Cycle Simulation: Application to the San Joaquin Valley, California

    Science.gov (United States)

    Davison, Jason; Hwang, Hyoun-Tae; Sudicky, Edward; Lin, John

    2015-04-01

    Groundwater reservoirs are drastically decreasing from the increased stresses of agricultural, industrial, and residential use. Across the world, groundwater levels continue to decline due to the expansion of human activities and the decrease in groundwater recharge. Methods commonly used to project the future decline in subsurface water storage involve simulating precipitation patterns and applying them independently to hydrological models without feedback between the atmospheric and the groundwater/surface water systems. However, it is becoming increasingly evident that this traditional methodology, which ignores the critical feedbacks between groundwater, the land-surface, and the atmosphere, is inappropriate at basin or larger scales. To improve upon conventional methods, we coupled HydroGeoSphere (HGS), a fully-integrated, physically-based, 3D surface/subsurface flow, solute and energy transport model that also accounts for land surface processes, to the Weather Research and Forecasting (WRF) model. WRF is a well-known nonhydrostatic finite-difference mesoscale weather model. Our flexible coupled model, referred to as HGS-WRF, directly links the water and energy fluxes between the surface/subsurface to the atmosphere, and allows HGS to maintain a finer unstructured mesh, while WRF uses a coarser mesh over the entire domain. We applied HGS-WRF to the San Joaquin Valley in central California and expect to see an increase in skill of energy and moisture fluxes between domains. Overall, the inclusion of atmospheric feedbacks in hydrologic models will increase their predictive capabilities and help better inform water managers.

  15. Estimated Altitude of the Top of the Uppermost Unit of Fine-Grained Sediment within the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated altitude of the top of the uppermost fine-grained sediment within the Wood River Valley aquifer system. This map was compiled by...

  16. Source apportionment of methane and nitrous oxide in California's San Joaquin Valley at CalNex 2010 via positive matrix factorization

    Science.gov (United States)

    Guha, A.; Gentner, D. R.; Weber, R. J.; Provencal, R.; Goldstein, A. H.

    2015-10-01

    Sources of methane (CH4) and nitrous oxide (N2O) were investigated using measurements from a site in southeast Bakersfield as part of the CalNex (California at the Nexus of Air Quality and Climate Change) experiment from mid-May to the end of June 2010. Typical daily minimum mixing ratios of CH4 and N2O were higher than daily minima that were simultaneously observed at a mid-oceanic background station (NOAA, Mauna Loa) by approximately 70 ppb and 0.5 ppb, respectively. Substantial enhancements of CH4 and N2O (hourly averages > 500 and > 7 ppb, respectively) were routinely observed, suggesting the presence of large regional sources. Collocated measurements of carbon monoxide (CO) and a range of volatile organic compounds (VOCs) (e.g., straight-chain and branched alkanes, cycloalkanes, chlorinated alkanes, aromatics, alcohols, isoprene, terpenes and ketones) were used with a positive matrix factorization (PMF) source apportionment method to estimate the contribution of regional sources to observed enhancements of CH4 and N2O. The PMF technique provided a "top-down" deconstruction of ambient gas-phase observations into broad source categories, yielding a seven-factor solution. We identified these emission source factors as follows: evaporative and fugitive; motor vehicles; livestock and dairy; agricultural and soil management; daytime light and temperature driven; non-vehicular urban; and nighttime terpene biogenics and anthropogenics. The dairy and livestock factor accounted for the majority of the CH4 (70-90 %) enhancements during the duration of experiments. The dairy and livestock factor was also a principal contributor to the daily enhancements of N2O (60-70 %). Agriculture and soil management accounted for ~ 20-25 % of N2O enhancements over a 24 h cycle, which is not surprising given that organic and synthetic fertilizers are known to be a major source of N2O. The N2O attribution to the agriculture and soil management factor had a high uncertainty in the

  17. Reservoir Operating Rule Optimization for California's Sacramento Valley

    OpenAIRE

    Nelson, Timothy; Hui, Rui; Lund, Jay; Medellín–Azuara, Josué

    2016-01-01

    doi: http://dx.doi.org/10.15447/sfews.2016v14iss1art6 Reservoir operating rules for water resource systems are typically developed by combining intuition, professional discussion, and simulation modeling. This paper describes a joint optimization–simulation approach to develop preliminary economically-based operating rules for major reservoirs in California’s Sacramento Valley, based on optimized results from CALVIN, a hydro-economic optimization model. We infer strategic o...

  18. Influence of fault trend, bends, and convergence on shallow structure and geomorphology of the Hosgri strike-slip fault, offshore central California

    Science.gov (United States)

    Johnson, Samuel Y.; Watt, Janet T.

    2012-01-01

    We mapped an ∼94-km-long portion of the right-lateral Hosgri fault zone in offshore central California using a dense network of high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. These data document the location, length, and continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergence in the development of shallow structure and tectonic geomorphology along strike-slip faults.

  19. Earthquake History of the Northern Imperial Fault, Imperial Valley, California, since the last Lake Cahuilla Highstand, circa A.D. 1680

    Science.gov (United States)

    Meltzner, A. J.; Rockwell, T. K.; Verdugo, D. M.

    2003-12-01

    The Imperial fault (IF) is the only fault in southern California to have ruptured in two major earthquakes in the 20th century. In 1940, it ruptured end-to-end (both north and south of the international border) in an M 6.9 earthquake, and in 1979, the northern segment of the fault (north of the border) ruptured again in an M 6.4 event. Slip in 1940 was highest (5-6 m) along the central portion of the fault and lowest (Rockwell, 1996). Prior to the present investigation, however, there were no data on events prior to 1940 on the northern patch, which could serve to either support or refute the slip-patch model. We have opened a trench across the IF south of Harris Road, adjacent to Mesquite Basin, where the fault has both dextral and normal slip components. On the downdropped side of the fault, a laminated clay unit (inferred to be the most recent LC clay, at ca. A.D. 1680; dating results are pending) is exposed in the trench and is overlain by nearly 2 m of younger deposits; the overlying material consists of bedded fine sands and silts (inferred to be overbank deposits from a nearby channel), which interfinger with massive silts and clays (inferred mostly to be colluvium). Unfortunately, the normal component of slip for all earthquakes in the trench was almost exclusively restricted to a single east-dipping plane or set of closely spaced planes, so that the amount of dip slip per event cannot be resolved; nonetheless, a series of fissures and flower structures adjacent to the main fault in the hangingwall block permit the distinction of individual events. There is good evidence for 4, and possibly 5 events since the last LC highstand, based on filled-in fissures and abrupt upward terminations of multiple fault strands and liquefaction cracks. The youngest of these events are inferred to be 1979 and 1940; the oldest, which produced liquefaction and ruptured to the top of the most recent lake deposits, probably occurred at or very soon after the highstand, based on

  20. Source apportionment of methane and nitrous oxide in California's San Joaquin Valley at CalNex 2010 via positive matrix factorization

    Directory of Open Access Journals (Sweden)

    A. Guha

    2015-03-01

    Full Text Available Sources of methane (CH4 and nitrous oxide (N2O were investigated using measurements from a site in southeast Bakersfield as part of the CalNex (California at the Nexus of Air Quality and Climate Change experiment from 15 May to 30 June 2010. Typical daily minimum mixing ratios of CH4 and N2O were higher than daily averages that were simultaneously observed at a similar latitude background station (NOAA, Mauna Loa by approximately 70 and 0.5 ppb, respectively. Substantial enhancements of CH4 and N2O (hourly averages > 500 ppb and > 7 ppb, respectively were routinely observed suggesting the presence of large regional sources. Collocated measurements of carbon monoxide (CO and a range of volatile organic compounds (VOCs (e.g. straight-chain and branched alkanes, cycloalkanes, chlorinated alkanes, aromatics, alcohols, isoprene, terpenes and ketones were used with a Positive Matrix Factorization (PMF source apportionment method to estimate the contribution of regional sources to observed enhancements of CH4 and N2O. The PMF technique provided a "top-down" deconstruction of ambient gas-phase observations into broad source categories, yielding a 7-factor solution. We identified these source factors as emissions from evaporative and fugitive; motor vehicles; livestock and dairy; agricultural and soil management; daytime light and temperature driven; non-vehicular urban; and nighttime terpene biogenics and anthropogenics. The dairy and livestock factor accounted for a majority of the CH4 (70–90% enhancements during the duration of the experiments. Propagation of uncertainties in the PMF-derived factor profiles and time series from bootstrapping analysis resulted in a 29% uncertainty in the CH4 apportionment to this factor. The dairy and livestock factor was also a principal contributor to the daily enhancements of N2O (60–70% with an uncertainty of 33%. Agriculture and soil management accounted for ~20–25% of N2O enhancements over the course of a

  1. Creeping Deformation by the Precise Leveling Survey at the central part of the Longitudinal valley fault, Southeast Taiwan

    Science.gov (United States)

    Matta, N.; Murase, M.; Ishiguro, S.; Ozawa, K.; Lin, J.; Chen, W.; Lin, C.

    2011-12-01

    We would like to know the distributed asperity for seismic hazard and forecast. It is closely related to slip distribution on the fault in interseismic. We focused on the accumulating process of the stress at the boundary between the creeping and the locking zone, to clear the behavior on the fault. The Longitudinal Valley Fault (LVF), 150 km long and NNE-SSW striking, passes through the eastern Taiwan, and represents the obvious surface expression of the collision boundary between the Philippine Sea plate and the Eurasian continental plate. Owing to such a high deformation rate, many earthquakes have occurred along the LVF. The 1951 earthquake sequence represents a good example. The southern of LVF segment is observed to be high speed creeping based on the creep meter and leveling survey etc. The northern of LVF segment is not observed to be creeping and are found huge earthquakes evidence by paleo-seismology study in the trench. Yuili fault is one of the active segments of the longitudinal valley faults, is located around the boundary between creeping and locking area. It is reverse fault with east dip. We established about 30km leveling route from Yuli to Changbin to detect the vertical deformation in detail. Murase et al. (2009, 2010, and 2011) established about 30 km densely leveling route from Yuli to Changbin to detect the vertical deformation across the LVF for two years. As a result, the vertical displacement is 1.7 cm in 200 m across the LVF and 2.7 cm in 1000 m, referred to the west end of our route. In addition, a synclinal deformation is detected on the hanging wall side of the fault. This result is caused by the geometry of and the slipping distribution on the fault. The deformation detected in the period from 2009 to 2010 denotes the same tendency and rate of that from 2008 to 2009. We compared to the airphotographs which are taken by Taiwanese government at different age (1978 and 2007). If the creeping on the fault has continued for 30 years, the

  2. The P-T-t history of blocks in serpentinite-matrix melange, west-central Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, S.L.; Harrison, T.M. [State Univ. of New York, Albany, NY (United States)

    1992-01-01

    Thermochronologic, petrologic, and geochemical analyses of epidote-amphibolite-, amphilbolite-, eclogite-, and blueschist-facies blocks in serpentinite-matrix melanges from East San Benito Island and Cedros Island, west-central Baja California, provide constraints on the P-T-t history of this disrupted terrane. Results of {sup 40}Ar/{sup 39}Ar step heating experiments on minerals separated from these blocks vary according to metamorphic grade and indicate different P-T-t histories. Mid-Jurassic (160-170 Ma) epidote-amphibolite- and amphibolite-facies blocks were probably derived from oceanic crust and associated sediments that were metamorphosed during limitation of subduction. Coarse-grained blueschist blocks were likely metamorphosed during continued subduction in late Early Cretaceous time (that is, 115-100 Ma). Some epidote-amphibolite blocks are partially overprinted by blueschist-facies mineral assemblages and apparently record both metamorphic events. Fission-track analyses of apatites indicate that the blocks underwent significantly different post-metamorphic cooling histories. Epidote-amphilbolite and amphibolite blocks cooled below {approximately}100 {degrees}C form mid-Jurassic to Paleocene time; blueschist blocks cooled below {approximately}100 {degrees}C in Oligocene-Miocene time. In general, mafic blocks have trace-element concentrations and REE patterns characteristic of ocean-flood basalts. This study demonstrates that samples with very different P-T-t histories can evidently occur over relatively small length scales (<<1 km) in serpentinite-matrix melanges. 67 refs., 16 figs., 4 tabs.

  3. Keeping the History in Historical Seismology: The 1872 Owens Valley, California Earthquake

    International Nuclear Information System (INIS)

    The importance of historical earthquakes is being increasingly recognized. Careful investigations of key pre-instrumental earthquakes can provide critical information and insights for not only seismic hazard assessment but also for earthquake science. In recent years, with the explosive growth in computational sophistication in Earth sciences, researchers have developed increasingly sophisticated methods to analyze macroseismic data quantitatively. These methodological developments can be extremely useful to exploit fully the temporally and spatially rich information source that seismic intensities often represent. For example, the exhaustive and painstaking investigations done by Ambraseys and his colleagues of early Himalayan earthquakes provides information that can be used to map out site response in the Ganges basin. In any investigation of macroseismic data, however, one must stay mindful that intensity values are not data but rather interpretations. The results of any subsequent analysis, regardless of the degree of sophistication of the methodology, will be only as reliable as the interpretations of available accounts - and only as complete as the research done to ferret out, and in many cases translate, these accounts. When intensities are assigned without an appreciation of historical setting and context, seemingly careful subsequent analysis can yield grossly inaccurate results. As a case study, I report here on the results of a recent investigation of the 1872 Owen's Valley, California earthquake. Careful consideration of macroseismic observations reveals that this event was probably larger than the great San Francisco earthquake of 1906, and possibly the largest historical earthquake in California. The results suggest that some large earthquakes in California will generate significantly larger ground motions than San Andreas fault events of comparable magnitude

  4. Estimated Altitude of the Consolidated Rock Surface Underlying Quaternary Sediments of the Wood River Valley aquifer system, South-Central Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the estimated altitude of the consolidated rock surface underlying Quaternary sediment of the Wood River Valley aquifer system. This surface is...

  5. Effects of reproductive experience on central expression of progesterone, oestrogen α, oxytocin and vasopressin receptor mRNA in male California mice (Peromyscus californicus)

    OpenAIRE

    Perea-Rodriguez, JP; Takahashi, EY; Amador, TM; Hao, RC; Saltzman, W; Trainor, BC

    2015-01-01

    © 2015 British Society for Neuroendocrinology. Fatherhood in biparental mammals is accompanied by distinct neuroendocrine changes in males, involving some of the same hormones involved in maternal care. In the monogamous, biparental California mouse (Peromyscus californicus), paternal care has been linked to changes in the central and/or peripheral availability of oestrogen, progesterone, vasopressin and oxytocin, although it is not known whether these endocrine fluctuations are associated wi...

  6. Pink bollworm integrated management using sterile insects under field trial conditions, Imperial Valley, California

    International Nuclear Information System (INIS)

    The pink bollworm moth (Pectinophora gossypiella Saunders) feeds almost exclusively on cotton (Gossypium spp.) and causes economic loss (Pfadt 1978). The pink bollworm (PBW) is often the key pest of cotton in Arizona, southern California, and northwestern Mexico. The larvae (immature stages) bore into the developing cotton fruit, where they feed on the cotton lint and seeds, causing significant damage and dramatically reducing the yield of cotton lint (Pfadt 1978). The PBW is difficult to control with conventional means (insecticides) because it spends the destructive larval phase inside the cotton boll where it is well protected from control measures. Cultural controls, such as a short growing season, have successfully decreased the population in the Imperial Valley (Chu et al. 1992) to the point where eradication may be possible using sterile insects and genetically engineered cotton. Because the PBW is an introduced insect, with few plant hosts other than cultivated cotton, its eradication from continental USA is a desirable and economically attractive alternative to the continued use of pesticides and/or further loss to the pest. Mass releases of sterile insects began in earnest in 1970 in the San Joaquin Valley, California, in order to inhibit normal reproduction and to eradicate the pest in an environmentally responsible manner. Sterile release involves mass production and sexual sterilisation using irradiation (20 krad for PBW adults). This was accomplished by building a rearing facility in Phoenix, AZ. The facility has 6,410 square metres of permanent laboratories, rearing and irradiation chambers and insect packing rooms. The facility operates the year round but with a variable production rate, that is, maximal during the cotton growing season (May through September). Sterile insect technology is based on the monitoring of the native and sterile populations in the field and the subsequent release of appropriate numbers of sterile insects in order to

  7. Non-lithogenic (autigenic and anthropogenic) uranium enrichments in the coastal marine sediments of the central Gulf of California

    International Nuclear Information System (INIS)

    Full text: Uranium geochemistry in the marine environment is considered as promising for a search of proxies for paleooceanographic reconstructions. High water primary production due to the utilization of the dissolved oxygen for the remineralization of settling organic particles generates suboxic or anoxic conditions in the intermediate oceanic waters favouring to the reduction of U(+6) existing in the sea water as truly dissolved form to U(+4) species, characterized by a low solubility and related high affinity to particles and sediments. To verify the possibilities of U enrichments in the marine sedimentary environment of the eastern sector of the central Gulf of California (GC), eleven sediment cores were collected in front of the Santa Rosalia mining region, peninsula of Baja California. Uranium and some other trace element contents in sliced core layers, dried and homogenized, were determined using instrumental neutron activation analysis. Average total U contents in sediments of five cores collected in the open GC in front of Santa Rosalia at the sites with a water depths from 265 m to 1030 m and in the Guaymas Basin (water depth 2019 m) ranged from 1.36 ± 0.26 mg/kg (Guaymas Basin) to 9.31 ± 3.03 mg/kg (SR63 core, depth 630 m). To distinguish non-lithogenic U from lithogenic one, the normalization of total U contents to the concentrations of Sc in the samples was used, because this element is a reliable indicator of crustal materials, mainly aluminosilicates in the marine sediments. The relative contribution of non-lithogenic (authigenic) U varied from 49.8 ± 3.0 % (Guaymas Basin) to 84.2 ± 8.2 % (SR62 core) of the total U content in the sediments of the open central GC. Surprisingly, in three sediment cores from the coastal zone adjacent to the town of Santa Rosalia in water depth range 3-6 m very high concentrations of total U were found, ranging from 54.2 ± 7.3 mg/kg ( SR4 core) to 110 ± 13 mg/kg (SR2 core) and exceeding not only U average

  8. Decadal Changes in Ozone and Emissions in Central California and Current Issues

    Science.gov (United States)

    Tanrikulu, S.; Beaver, S.; Soong, S.; Tran, C.; Cordova, J.; Palazoglu, A.

    2011-12-01

    The relationships among ozone, emissions, and meteorology are very complex in central California, and must be well studied and understood in order to facilitate better air quality planning. Factors significantly impacting changes in emissions such as economic and population growth, and adopted emission controls make the matter even more complex. Here we review the history of ozone pollution in central California since the 1970s to plan for the future. Since the 1970s, changes in emissions have been accompanied by likewise dramatic changes in region-to-region differences in air quality. We focus on the coastal San Francisco Bay Area (SFBA) and the inland San Joaquin Valley (SJV). In the 1970s, the SFBA population was approaching 5 million people while the considerably larger and more rural SJV population remained below 2 million. The SFBA population was mostly confined to coastal locations. Peak ozone levels occurred mostly around the population centers and especially over the Bay itself. Hourly average ozone levels routinely approached 160 ppb. These high ozone levels promoted regulations under which SFBA emissions were continuously reduced through the present. By the 1990s, SFBA emissions had been reduced considerably despite the region's population growing to around 6 million. Relative to the 1970s, in 1990s the SFBA had lower peak ozone levels that were shifted to inland locations where much of the population growth was occurring. The SFBA still exceeded the federal 1-hour standard. A rapidly changing economic landscape in the 1970s promoted vast changes in the central California population distribution. In the SJV, the OPEC oil crisis promoted significant development of petroleum resources. Meanwhile, family farms were quickly being replaced with commercial-scale farming operations. The SJV population rapidly expanded to around 3 million people by the early 1990s. During this time, SJV emissions increased considerably, largely from increases in mobile source

  9. Geochronology of blueschists from west-central Baja California and the timing of uplift in subduction complexes

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, S.L.; Harrison, T.M. (Dept. of Geol. Sciences, Albany, NY (USA))

    1989-03-01

    A geochronologic study of blueschists from west-central Baja California has provided constraints on the timing of high-pressure, low-temperature metamorphism and the subsequent uplift of this subduction complex. Mineral separates from coherent blueschists and blueschist blocks enclosed in serpentinite melange were analyzed by {sup 40}Ar/{sup 39}Ar, fission track, and Rb/Sr methods. {sup 40}Ar/{sup 39}Ar age spectra for white mica separated from four blueschist blocks and an overprinted eclogite block in serpentinite-matrix melange show slow cooling gradients between 115-95 Ma. Rb/Sr apparent ages for one block are concordant with these results. {sup 40}Ar/{sup 39}Ar ages of blue amphibole are primarily the result of the degassing of white mica intergrowths as confirmed by microprobe analyses. Apatite fission track ages indicate a blueschist block and an eclogite block cooled to a temperature below {approximately}100 C at 22 Ma and 32 Ma, respectively. Subduction-related metamorphism of the coherent blueschists occurred in late Early Cretaceous time, based on a {sup 40}Ar/{sup 39}Ar age or 109 Ma for metamorphic white mica from a metasandstone. {sup 40}Ar/{sup 39}Ar analysis of partially albitized K-feldspar from a plutonic clast in a metaconglomerate indicates this sample cooled to a temperature of {approximately} 145 C at approximately 20 Ma. Geochronologic and petrologic data for coherent blueschists indicate an average uplift rate of 0.1 mm/yr for one portion of the subduction complex. The relatively slow uplift rate and lack of any higher temperature overprinting assemblages in the coherent blueschists suggest that synsubduction uplift was gradual and proceeded through a dynamic accretionary wedge characterized by low geothermal gradients. An increase in uplift rate (to 1.0 mm/yr) during post-Miocene time coincides with a change from a convergent to a transform plate boundary.

  10. Prevalence of shiga toxin producing Escherichia coli, Salmonella enterica, and Listeria monocytogenes at public access watershed sites in a California Central Coast agricultural region

    OpenAIRE

    Cooley, Michael B.; Quiñones, Beatriz; Oryang, David; Mandrell, Robert E.; Gorski, Lisa

    2014-01-01

    Produce contaminated with enteric pathogens is a major source of foodborne illness in the United States. Lakes, streams, rivers, and ponds were sampled with Moore swabs bi-monthly for over 2 years at 30 locations in the vicinity of a leafy green growing