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Sample records for san joaquin rivers

  1. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Natural Resource Agency — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  2. Proposed Strategy for San Joaquin River Basin Water Quality Monitoring and Assessment

    Science.gov (United States)

    A Proposed Strategy for San Joaquin River Basin Water Quality Monitoring and Assessment was published in 2010, and a Strawman Proposal was developed in 2012 by the Coalition for Urban/Rural Environmental Stewardship, California Water Resources Board, EPA.

  3. 78 FR 39597 - Safety Zone; Hilton Fourth of July Fireworks, San Joaquin River, Venice Island, CA

    Science.gov (United States)

    2013-07-02

    ... Zone; Hilton Fourth of July Fireworks, San Joaquin River, Venice Island, CA AGENCY: Coast Guard, DHS... the Hilton Fourth of July Fireworks in the Captain of the Port, San Francisco area of responsibility...'' W (NAD83) for the Hilton Fourth of July Fireworks in 33 CFR 165.1191, Table 1, Item number 17. This...

  4. Isotopic Evidence of Nitrate Sources and its Relationship to Algae in the San Joaquin River, California

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Young, M. B.; Stringfellow, W. T.; Borglin, S. E.; Kratzer, C. R.; Dahlgren, R. A.; Schmidt, C.; Rollog, M. E.

    2007-12-01

    Many competing demands have been placed on the San Joaquin River including deep water shipping, use as agricultural and drinking water, transport of agricultural and urban runoff, and recreation. These long-established demands limit the management options and increase the importance of understanding the river dynamics. The relationships among sources of water, nitrate, and algae in the San Joaquin River must be understood before management decisions can be made to optimize aquatic health. Isotopic analyses of water samples collected along the San Joaquin River in 2005-2007 have proven useful in assessing these relationships: sources of nitrate, the productivity of the San Joaquin River, and the relationship between nitrate and algae in the river. The San Joaquin River receives water locally from wetlands and agricultural return flow, and from three relatively large tributaries whose headwaters are in the Sierra Nevada. The lowest nitrate concentrations occur during periods of high flow when the proportion of water from the Sierra Nevada is relatively large, reflecting the effect of dilution from the big tributaries and indicating that a large fraction of the nitrate is of local origin. Nitrogen isotopes of nitrate in the San Joaquin River are relatively high (averaging about 12 per mil), suggesting a significant source from animal waste or sewage and/or the effects of denitrification. The d15N of nitrate varies inversely with concentration, indicating that these high isotopic values are also a local product. The d15N values of nitrate from most of the local tributaries is lower than that in the San Joaquin suggesting that nitrate from these tributaries does not account for a significant fraction of nitrate in the river. The source of the non-tributary nitrate must be either small unmeasured surface inputs or groundwater. To investigate whether groundwater might be a significant source of nitrate to the San Joaquin River, groundwater samples are being collected

  5. Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California

    Directory of Open Access Journals (Sweden)

    Alan D. Jassby

    2005-03-01

    Full Text Available As in many U.S. estuaries, the tidal San Joaquin River exhibits elevated organic matter production that interferes with beneficial uses of the river, including fish spawning and migration. High phytoplankton biomass in the tidal river is consequently a focus of management strategies. An unusually long and comprehensive monitoring dataset enabled identification of the determinants of phytoplankton biomass. Phytoplankton carrying capacity may be set by nitrogen or phosphorus during extreme drought years but, in most years, growth rate is light-limited. The size of the annual phytoplankton bloom depends primarily on river discharge during late spring and early summer, which determines the cumulative light exposure in transit downstream. The biomass-discharge relationship has shifted over the years, for reasons as yet unknown. Water diversions from the tidal San Joaquin River also affect residence time during passage downstream and may have resulted in more than a doubling of peak concentration in some years. Dam construction and accompanying changes in storage-and-release patterns from upstream reservoirs have caused a long-term decrease in the frequency of large blooms since the early 1980s, but projected climate change favors a future increase. Only large decreases in nonpoint nutrient sources will limit phytoplankton biomass reliably. Growth rate and concentration could increase if nonpoint source management decreases mineral suspensoid load but does not decrease nutrient load sufficiently. Small changes in water storage and release patterns due to dam operation have a major influence on peak phytoplankton biomass, and offer a near-term approach for management of nuisance algal blooms.

  6. Concept Paper for Real-Time Temperature and Water QualityManagement for San Joaquin River Riparian Habitat Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Nigel W.T.

    2004-12-20

    The San Joaquin River Riparian Habitat Restoration Program (SJRRP) has recognized the potential importance of real-time monitoring and management to the success of the San Joaquin River (SJR) restoration endeavor. The first step to realizing making real-time management a reality on the middle San Joaquin River between Friant Dam and the Merced River will be the installation and operation of a network of permanent telemetered gauging stations that will allow optimization of reservoir releases made specifically for fish water temperature management. Given the limited reservoir storage volume available to the SJJRP, this functionality will allow the development of an adaptive management program, similar in concept to the VAMP though with different objectives. The virtue of this approach is that as management of the middle SJR becomes more routine, additional sensors can be added to the sensor network, initially deployed, to continue to improve conditions for anadromous fish.

  7. Real-time management of water quality in the San Joaquin River Basin, California.

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T.; Karkoski, J.

    1997-09-01

    In the San Joaquin River Basin, California, a realtime water quality forecasting model was developed to help improve the management of saline agricultural and wetland drainage to meet water quality objectives. Predicted salt loads from the water quality forecasting model, SJRIODAY, were consistently within +- 11 percent of actual, within +- 14 percent for seven-day forecasts, and with in +- 26 percent for 14-day forecasts for the 16-month trial period. When the 48 days dominated by rainfall/runoff events were eliminated from the data set, the error bar decreased to +- 9 percent for the model and +- 11 percent and +- 17 percent for the seven-day and 14-day forecasts, respectively. Constraints on the use of the model for salinity management on the San Joaquin River include the number of entities that control or influence water quality and the lack of a centralized authority to direct their activities. The lack of real-time monitoring sensors for other primary constituents of concern, such as selenium and boron, limits the application of the model to salinity at the present time. A case study describes wetland drainage releases scheduled to coincide with high river flows and significant river assimilative capacity for salt loads.

  8. Occurrence and distribution of dissolved pesticides in the San Joaquin River basin, California

    Science.gov (United States)

    Panshin, Sandra Yvonne; Dubrovsky, Neil M.; Gronberg, JoAnn M.; Domagalski, Joseph L.

    1998-01-01

    The effects of pesticide application, hydrology, and chemical and physical properties on the occurrence of pesticides in surface water in the San Joaquin River Basin, California, were examined. The study of pesticide occurrence in the highly agricultural San Joaquin?Tulare Basins is part of the National Water-Quality Assessment Program of the U.S. Geological Survey. One hundred forty-three water samples were collected throughout 1993 from sites on the San Joaquin River and three of its tributaries: Orestimba Creek, Salt Slough, and the Merced River. Of the 83 pesticides selected for analysis in this study, 49 different compounds were detected in samples from the four sites and ranged in concentration from less than the detection limit to 20 micrograms per liter. All but one sample contained at least one pesticide, and more than 50 percent of the samples contained seven or more pesticides. Six compounds were detected in more than 50 percent of the samples: four herbicides (dacthal, EPTC, metolachlor, and simazine) and two insecticides (chlorpyrifos and diazinon). None of the measured concentrations exceeded U.S. Environmental Protection Agency drinking water criteria, and many of the measured concentrations were very low. The concentrations of seven pesticides exceeded criteria for the protection of freshwater aquatic life: azinphos-methyl, carbaryl, chlorpyrifos, diazinon, diuron, malathion, and trifluralin. Overall, some criteria for protection of aquatic life were exceeded in a total of 97 samples. Factors affecting the spatial patterns of occurrence of the pesticides in the different subbasins included the pattern of application and hydrology. Seventy percent of pesticides with known application were detected. Overall, 40 different pesticides were detected in Orestimba Creek, 33 in Salt Slough, and 26 in the Merced River. Samples from the Merced River had a relatively low number of detections, despite the high number (35) of pesticides applied, owing to the

  9. 75 FR 71145 - San Joaquin River Restoration Program: Reach 4B, Eastside Bypass, and Mariposa Bypass Channel and...

    Science.gov (United States)

    2010-11-22

    ..., Eastside Bypass, and Mariposa Bypass Channel and Structural Improvements Project, Merced County, CA AGENCY... on the effects of the proposed Reach 4B, Eastside Bypass, and Mariposa Bypass Channel and Structural... Mariposa Bypass with the San Joaquin River (generally referred to as Reach 4B1). The improvements will...

  10. Physical characteristics of the lower San Joaquin River, California, in relation to white sturgeon spawning habitat, 2011–14

    Science.gov (United States)

    Marineau, Mathieu D.; Wright, Scott A.; Whealdon-Haught, Daniel R.; Kinzel, Paul J.

    2017-07-19

    The U.S. Fish and Wildlife Service confirmed that white sturgeon (Acipenser transmontanus) recently spawned in the lower San Joaquin River, California. Decreases in the San Francisco Bay estuary white sturgeon population have led to an increased effort to understand their migration behavior and habitat preferences. The preferred spawning habitat of other white sturgeon (for example, those in the Columbia and Klamath Rivers) is thought to be areas that have high water velocity, deep pools, and coarse bed material. Coarse bed material (pebbles and cobbles), in particular, is important for the survival of white sturgeon eggs and larvae. Knowledge of the physical characteristics of the lower San Joaquin River can be used to preserve sturgeon spawning habitat and lead to management decisions that could help increase the San Francisco Bay estuary white sturgeon population.Between 2011 and 2014, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, assessed selected reaches and tributaries of the lower river in relation to sturgeon spawning habitat by (1) describing selected spawning reaches in terms of habitat-related physical characteristics (such as water depth and velocity, channel slope, and bed material) of the lower San Joaquin River between its confluences with the Stanislaus and Merced Rivers, (2) describing variations in these physical characteristics during wet and dry years, and (3) identifying potential reasons for these variations.The lower San Joaquin River was divided into five study reaches. Although data were collected from all study reaches, three subreaches where the USFWS collected viable eggs at multiple sites in 2011–12 from Orestimba Creek to Sturgeon Bend were of special interest. Water depth and velocity were measured using two different approaches—channel cross sections and longitudinal profiles—and data were collected using an acoustic Doppler current profiler.During the first year of data collection (water

  11. Dissolved pesticide concentrations entering the Sacramento-San Joaquin Delta from the Sacramento and San Joaquin Rivers, California, 2012-13

    Science.gov (United States)

    Orlando, James L.; McWayne, Megan; Sanders, Corey; Hladik, Michelle

    2014-01-01

    Surface-water samples were collected from the Sacramento and San Joaquin Rivers where they enter the Sacramento–San Joaquin Delta, and analyzed by the U.S. Geological Survey for a suite of 99 current-use pesticides and pesticide degradates. Samples were collected twice per month from May 2012 through July 2013 and from May 2012 through April 2013 at the Sacramento River at Freeport, and the San Joaquin River near Vernalis, respectively. Samples were analyzed by two separate laboratory methods by using gas chromatography with mass spectrometry or liquid chromatography with tandem mass spectrometry. Method detection limits ranged from 0.9 to 10.5 nanograms per liter (ng/L). A total of 37 pesticides and degradates were detected in water samples collected during the study (18 herbicides, 11 fungicides, 7 insecticides, and 1 synergist). The most frequently detected pesticides overall were the herbicide hexazinone (detected in 100 percent of the samples); 3,4-dichloroaniline (97 percent), which is a degradate of the herbicides diuron and propanil; the fungicide azoxystrobin (83 percent); and the herbicides diuron (72 percent), simazine (66 percent), and metolachlor (64 percent). Insecticides were rarely detected during the study. Pesticide concentrations varied from below the method detection limits to 984 ng/L (hexazinone). Twenty seven pesticides and (or) degradates were detected in Sacramento River samples, and the average number of pesticides per sample was six. The most frequently detected compounds in these samples were hexazinone (detected in 100 percent of samples), 3,4-dichloroaniline (97 percent), azoxystrobin (88 percent), diuron (56 percent), and simazine (50 percent). Pesticides with the highest detected maximum concentrations in Sacramento River samples included the herbicide clomazone (670 ng/L), azoxystrobin (368 ng/L), 3,4-dichloroaniline (364 ng/L), hexazinone (130 ng/L), and propanil (110 ng/L), and all but hexazinone are primarily associated with

  12. Dissolved Pesticide Concentrations Detected in Storm-Water Runoff at Selected Sites in the San Joaquin River Basin, California, 2000-2001

    National Research Council Canada - National Science Library

    Orlando, James L; Kuivila, Kathryn M; Whitehead, Andrew

    2003-01-01

    ...) and the University of California Davis Bodega Marine Laboratory (BML) water samples were collected at three sites within the San Joaquin River Basin of California and analyzed for dissolved pesticides...

  13. Concentrations and loads of suspended sediment-associated pesticides in the San Joaquin River, California and tributaries during storm events

    Science.gov (United States)

    Hladik, M.L.; Domagalski, Joseph L.; Kuivila, K.M.

    2009-01-01

    Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3000 ng/g; median of 6.1 ng/g) were generally greater than those for the insecticides (0.2 to 51 ng/g; median of 1.5 ng/g). Concentrations in the tributaries were usually greater than in the mainstem San Joaquin River and the west side tributaries were higher than the east side tributaries. Estimated instantaneous loads ranged from 1.3 to 320 g/day for herbicides and 0.03 to 53 g/day for insecticides. The greatest instantaneous loads came from the Merced River on the east side. Instantaneous loads were greater for the first storm of 2008 than the second storm in the tributaries while the instantaneous loads within the San Joaquin River were greater during the second storm. Pesticide detections generally reflected pesticide application, but other factors such as physical-chemical properties and timing of application were also important to pesticide loads.

  14. Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta

    Science.gov (United States)

    Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

    2012-01-01

    Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and marsh habitats. The model demonstrates feedback loops that affect the Delta ecosystem. Submerged and emergent marsh vegetation act as ecosystem engineers that can create a positive feedback loop by decreasing suspended sediment, increasing water column light, which in turn enables more vegetation. Sea-level rise in open water is partially countered by a negative feedback loop that increases deposition if there is a net decrease in hydrodynamic energy. Manipulation of regional sediment transport is probably the most feasible method to control suspended sediment and thus turbidity. The conceptual model is used to identify information gaps that need to be filled to develop an accurate sediment transport model.

  15. Dispersion Mechanisms of a Tidal River Junction in the Sacramento–San Joaquin Delta, California

    Directory of Open Access Journals (Sweden)

    Karla T. Gleichauf

    2014-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2014v12iss4art1In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP boat transecting and moored ADCPs over a spring–neap tidal cycle (May to  June 2012 monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011 advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales. The study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby

  16. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    Science.gov (United States)

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was −254‰ in agricultural drains in the Sacramento–San Joaquin Delta, −218‰ in the San Joaquin River, −175‰ in the California State Water Project and −152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California’s Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, −204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between −275 and −687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California’s Central Valley.

  17. Isotopic and Chemical Analysis of Nitrate Sources and Cycling in the San Joaquin River Near Stockton, California

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Bemis, B.; Wankel, S.; Bergamaschi, B.; Kratzer, C.; Dileanis, P.; Erickson, D.; Avery, E.; Paxton, K.

    2002-12-01

    Fish migration through the deep-water channel in the San Joaquin River at Stockton, California is inhibited by low oxygen concentrations during the summer months. The cause for this condition appears to be stagnation and decomposition of algae with attendant oxygen consumption. Algae growth in the San Joaquin River is promoted by nutrients entering the river mainly in the form of nitrate. Possible significant sources of nitrate include soil, fertilizer from agriculture, manure from dairy operations, and N derived from municipal sewage. A 2000 CALFED pilot study investigated the sources and cycling of nitrate at four sites along the San Joaquin River upstream of Stockton using the carbon and nitrogen isotopes of total dissolved and particulate organic matter, together with hydrological measurements and various concentration data, including chlorophyll-a. The nitrate source, its relationship to phytoplankton, and the effect of the nitrate source and cycling on the N isotopic composition of dissolved and particulate organic matter were the primary concerns of the study. The d15N values of dissolved organic nitrogen (DON) were used as a proxy for nitrate d15N because nitrate comprised about 90% of DON. Chlorophyll-a and C:N ratios indicated that the particulate organic matter (POM) consisted largely of plankton and therefore the d15N of POM was used as a proxy for the d15N of plankton. A tentative interpretation of the pilot study was that nitrate was a major nutrient for the plankton and the nitrate was of anthropogenic origin, possibly sewage or animal waste. To test these assumptions and interpretations, we are currently analyzing a set of samples collected in 2001. In addition to the previous sample types, a subset of samples will be measured directly for nitrate d15N to assess the validity of using d15N of DON as a proxy for nitrate.

  18. Assessment of interim flow water-quality data of the San Joaquin River restoration program and implications for fishes, California, 2009-11

    Science.gov (United States)

    Wulff, Marissa L.; Brown, Larry R.

    2015-01-01

    After more than 50 years of extensive water diversion for urban and agriculture use, a major settlement was reached among the U.S. Departments of the Interior and Commerce, the Natural Resources Defense Council, and the Friant Water Users Authority in an effort to restore the San Joaquin River. The settlement received Federal court approval in October 2006 and established the San Joaquin River Restoration Program, a multi-agency collaboration between State and Federal agencies to restore and maintain fish populations, including Chinook salmon, in the main stem of the river between Friant Dam and the confluence with the Merced River. This is to be done while avoiding or minimizing adverse water supply effects to all of the Friant Division contractors that could result from restoration flows required by the settlement. The settlement stipulates that water- and sediment-quality data be collected to help assess the restoration goals. This report summarizes and evaluates water-quality data collected in the main stem of the San Joaquin River between Friant Dam and the Merced River by the U.S. Bureau of Reclamation for the San Joaquin River Restoration Program during 2009-11. This summary and assessment consider sampling frequency for adequate characterization of variability, sampling locations for sufficient characterization of the San Joaquin River Restoration Program restoration reach, sampling methods for appropriate media (water and sediment), and constituent reporting limits. After reviewing the water- and sediment-quality results for the San Joaquin River Restoration Program, several suggestions were made to the Fisheries Management Work Group, a division of the San Joaquin River Restoration Program that focuses solely on the reintroduction strategies and health of salmon and other native fishes in the river. Water-quality results for lead and total organic carbon exceeded the Surface Water Ambient Monitoring Program Basin Plan Objectives for the San Joaquin Basin

  19. Design and implementation of an emergency environmental responsesystem to protect migrating salmon in the lower San Joaquin River,California

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Nigel W.T.; Jacobs, Karl C.

    2006-01-30

    In the past decade tens of millions of dollars have beenspent by water resource agencies in California to restore the nativesalmon fishery in the San Joaquin River and its major tributaries. Anexcavated deep water ship channel (DWSC), through which the river runs onits way to the Bay/Delta and Pacific Ocean, experiences episodes of lowdissolved oxygen which acts as a barrier to anadromous fish migration anda threat to the long-term survival of the salmon run. An emergencyresponse management system is under development to forecast theseepisodes of low dissolved oxygen and to deploy measures that will raisedissolved oxygen concentrations to prevent damage to the fisheryresource. The emergency response management system has been designed tointeract with a real-time water quality monitoring network and is servedby a comprehensive data management and forecasting model toolbox. TheBay/Delta and Tributaries (BDAT) Cooperative Data Management System is adistributed, web accessible database that contains terabytes ofinformation on all aspects of the ecology of the Bay/Delta and upperwatersheds. The complexity of the problem dictates data integration froma variety of monitoring programs. A unique data templating system hasbeen constructed to serve the needs of cooperating scientists who wish toshare their data and to simplify and streamline data uploading into themaster database. In this paper we demonstrate the utility of such asystem in providing decision support for management of the San JoaquinRiver fishery. We discuss how the system might be expanded to havefurther utility in coping with other emergencies and threats to watersupply system serving California's costal communities.

  20. Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

    Science.gov (United States)

    Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Jr., Robert R.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken

    2004-01-01

    Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

  1. 33 CFR 162.205 - Suisun Bay, San Joaquin River, Sacramento River, and connecting waters, CA.

    Science.gov (United States)

    2010-07-01

    ... Commander or his authorized representative. (5) Wrecks. In no case following accidents of fire or collision...); a wharf or other structure; work under construction; plant engaged in river and harbor improvement... navigable channels, when within a reasonable distance therefrom and not in any case over a mile, shall...

  2. Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

    Science.gov (United States)

    Burau, Jon; Ruhl, Cathy; Work, Paul A.

    2016-01-29

    The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

  3. Recent research on the hydrodynamics of the Sacramento - San Joaquin River Delta and north San Francisco Bay

    Science.gov (United States)

    Burau, J.R.; Monismith, S.G.; Stacey, M.T.; Oltmann, R.N.; Lacy, J.R.; Schoellhamer, D.H.

    1999-01-01

    This article presents an overview of recent findings from hydrodynamic research on circulation and mixing in the Sacramento-San Joaquin Delta (Delta) (Figure 1) and North San Francisco Bay (North Bay) (Figure 2). For the purposes of this article, North Bay includes San Pablo Bay, Carquinez Strait, and Suisun Bay. The findings presented are those gained from field studies carried out by the U.S. Geological Survey (USGS), as part of the Interagency Ecological Program (IEP), and Stanford University beginning about 1993. The premise behind these studies was that a basic understanding of circulation and mixing patterns in the Bay and Delta is an essential part of understanding how biota and water quality are affected by natural hydrologic variability, water appropriation, and development activities. Data collected for the field studies described in this article have significantly improved our understanding of Bay and Delta hydrodynamics. Measured flows ,in the Delta have provided valuable information on how water moves through the Delta's network of channels and how export pumping affects flows. Studies of the shallows and shallow-channel exchange processes conducted in Honker Bay have shown that the water residence time in Honker Bay is much shorter than previously reported (on the order of hours to several tidal cycles instead ofweeks). Suisun Bay studies have provided data on hydrodynamic transport and accumulation mechanisms that operate primarily in the channels. The Suisun Bay studies have caused us to revise our understanding of residual circulation in the channels of North Bay and of "entrapment" mechanisms in the low salinity zone. Finally, detailed tidal and residual (tidally averaged) time-scale studies of the mechanisms that control gravitational circulation in the estuary show that density-driven transport in the channels is governed by turbulence time-scale (seconds) interactions between the mean flow and stratification. The hydrodynamic research

  4. Documentation of a groundwater flow model (SJRRPGW) for the San Joaquin River Restoration Program study area, California

    Science.gov (United States)

    Traum, Jonathan A.; Phillips, Steven P.; Bennett, George L.; Zamora, Celia; Metzger, Loren F.

    2014-01-01

    To better understand the potential effects of restoration flows on existing drainage problems, anticipated as a result of the San Joaquin River Restoration Program (SJRRP), the U.S. Geological Survey (USGS), in cooperation with the U.S. Bureau of Reclamation (Reclamation), developed a groundwater flow model (SJRRPGW) of the SJRRP study area that is within 5 miles of the San Joaquin River and adjacent bypass system from Friant Dam to the Merced River. The primary goal of the SJRRP is to reestablish the natural ecology of the river to a degree that restores salmon and other fish populations. Increased flows in the river, particularly during the spring salmon run, are a key component of the restoration effort. A potential consequence of these increased river flows is the exacerbation of existing irrigation drainage problems along a section of the river between Mendota and the confluence with the Merced River. Historically, this reach typically was underlain by a water table within 10 feet of the land surface, thus requiring careful irrigation management and (or) artificial drainage to maintain crop health. The SJRRPGW is designed to meet the short-term needs of the SJRRP; future versions of the model may incorporate potential enhancements, several of which are identified in this report. The SJRRPGW was constructed using the USGS groundwater flow model MODFLOW and was built on the framework of the USGS Central Valley Hydrologic Model (CVHM) within which the SJRRPGW model domain is embedded. The Farm Process (FMP2) was used to simulate the supply and demand components of irrigated agriculture. The Streamflow-Routing Package (SFR2) was used to simulate the streams and bypasses and their interaction with the aquifer system. The 1,300-square mile study area was subdivided into 0.25-mile by 0.25-mile cells. The sediment texture of the aquifer system, which was used to distribute hydraulic properties by model cell, was refined from that used in the CVHM to better represent

  5. The effect of submerged aquatic vegetation expansion on a declining turbidity trend in the Sacramento-San Joaquin River Delta

    Science.gov (United States)

    Hestir, E.L.; Schoellhamer, David H.; Jonathan Greenberg,; Morgan-King, Tara L.; Ustin, S.L.

    2016-01-01

    Submerged aquatic vegetation (SAV) has well-documented effects on water clarity. SAV beds can slow water movement and reduce bed shear stress, promoting sedimentation and reducing suspension. However, estuaries have multiple controls on turbidity that make it difficult to determine the effect of SAV on water clarity. In this study, we investigated the effect of primarily invasive SAV expansion on a concomitant decline in turbidity in the Sacramento-San Joaquin River Delta. The objective of this study was to separate the effects of decreasing sediment supply from the watershed from increasing SAV cover to determine the effect of SAV on the declining turbidity trend. SAV cover was determined by airborne hyperspectral remote sensing and turbidity data from long-term monitoring records. The turbidity trends were corrected for the declining sediment supply using suspended-sediment concentration data from a station immediately upstream of the Delta. We found a significant negative trend in turbidity from 1975 to 2008, and when we removed the sediment supply signal from the trend it was still significant and negative, indicating that a factor other than sediment supply was responsible for part of the turbidity decline. Turbidity monitoring stations with high rates of SAV expansion had steeper and more significant turbidity trends than those with low SAV cover. Our findings suggest that SAV is an important (but not sole) factor in the turbidity decline, and we estimate that 21–70 % of the total declining turbidity trend is due to SAV expansion.

  6. Effect of tides, river flow, and gate operations on entrainment of juvenile salmon into the interior Sacramento–San Joaquin River Delta

    Science.gov (United States)

    Perry, Russell W.; Brandes, Patricia L.; Burau, Jon R.; Sandstrom, Philip T.; Skalski, John R.

    2015-01-01

    Juvenile Chinook Salmon Oncorhynchus tshawytscha emigrating from natal tributaries of the Sacramento River, California, must negotiate the Sacramento-San Joaquin River Delta (hereafter, the Delta), a complex network of natural and man-made channels linking the Sacramento River with San Francisco Bay. Fish that enter the interior and southern Delta—the region to the south of the Sacramento River where water pumping stations are located—survive at a lower rate than fish that use alternative migration routes. Consequently, total survival decreases as the fraction of the population entering the interior Delta increases, thus spurring management actions to reduce the proportion of fish that are entrained into the interior Delta. To better inform management actions, we modeled entrainment probability as a function of hydrodynamic variables. We fitted alternative entrainment models to telemetry data that identified when tagged fish in the Sacramento River entered two river channels leading to the interior Delta (Georgiana Slough and the gated Delta Cross Channel). We found that the probability of entrainment into the interior Delta through both channels depended strongly on the river flow and tidal stage at the time of fish arrival at the river junction. Fish that arrived during ebb tides had a low entrainment probability, whereas fish that arrived during flood tides (i.e., when the river's flow was reversed) had a high probability of entering the interior Delta. We coupled our entrainment model with a flow simulation model to evaluate the effect of nighttime closures of the Delta Cross Channel gates on the daily probability of fish entrainment into the interior Delta. Relative to 24-h gate closures, nighttime closures increased daily entrainment probability by 3 percentage points on average if fish arrived at the river junction uniformly throughout the day and by only 1.3 percentage points if 85% of fish arrived at night. We illustrate how our model can be used to

  7. Distribution and Joint Fish-Tag Survival of Juvenile Chinook Salmon Migrating through the Sacramento-San Joaquin River Delta, California, 2008

    Science.gov (United States)

    Holbrook, Christopher M.; Perry, Russell W.; Adams, Noah S.

    2009-01-01

    Acoustic telemetry was used to obtain the movement histories of 915 juvenile fall-run Chinook salmon (Oncorhynchus tshawytscha) through the lower San Joaquin River and Sacramento-San Joaquin Delta, California, in 2008. Data were analyzed within a release-recapture framework to estimate survival, route distribution, and detection probabilities among three migration pathways through the Delta. The pathways included the primary route through the San Joaquin River and two less direct routes (Old River and Turner Cut). Strong inferences about survival were limited by premature tag failure, but estimates of fish distribution among migration routes should be unaffected by tag failure. Based on tag failure tests (N = 66 tags), we estimated that only 55-78 percent of the tags used in this study were still functioning when the last fish was detected exiting the study area 15 days after release. Due to premature tag failure, our 'survival' estimates represent the joint probability that both the tag and fish survived, not just survival of fish. Low estimates of fish-tag survival could have been caused by fish mortality or fish travel times that exceeded the life of the tag, but we were unable to differentiate between the two. Fish-tag survival through the Delta (from Durham Ferry to Chipps Island by all routes) ranged from 0.05 +or- 0.01 (SE) to 0.06 +or- 0.01 between the two weekly release groups. Among the three migration routes, fish that remained in the San Joaquin River exhibited the highest joint fish-tag survival (0.09 +or- 0.02) in both weeks, but only 22-33 percent of tagged fish used this route, depending on the week of release. Only 4-10 percent (depending on week) of tagged fish traveled through Turner Cut, but no tagged fish that used this route were detected exiting the Delta. Most fish (63-68 percent, depending on week of release) migrated through Old River, but fish-tag survival through this route (0.05 +or- 0.01) was only about one-half that of fish that

  8. Assessing the sources and magnitude of diurnal nitrate variability in the San Joaquin River (California) with an in situ optical nitrate sensor and dual nitrate isotopes

    Science.gov (United States)

    Pellerin, Brian A.; Downing, Bryan D.; Kendall, Carol; Dahlgren, Randy A.; Kraus, Tamara E.C.; Saraceno, John Franco; Spencer, Robert G. M.; Bergamaschi, Brian A.

    2009-01-01

    1. We investigated diurnal nitrate (NO3−) concentration variability in the San Joaquin River using an in situ optical NO3− sensor and discrete sampling during a 5‐day summer period characterized by high algal productivity. Dual NO3− isotopes (δ15NNO3 and δ18ONO3) and dissolved oxygen isotopes (δ18ODO) were measured over 2 days to assess NO3− sources and biogeochemical controls over diurnal time‐scales.2. Concerted temporal patterns of dissolved oxygen (DO) concentrations and δ18ODOwere consistent with photosynthesis, respiration and atmospheric O2 exchange, providing evidence of diurnal biological processes independent of river discharge.3. Surface water NO3− concentrations varied by up to 22% over a single diurnal cycle and up to 31% over the 5‐day study, but did not reveal concerted diurnal patterns at a frequency comparable to DO concentrations. The decoupling of δ15NNO3 and δ18ONO3isotopes suggests that algal assimilation and denitrification are not major processes controlling diurnal NO3− variability in the San Joaquin River during the study. The lack of a clear explanation for NO3− variability likely reflects a combination of riverine biological processes and time‐varying physical transport of NO3− from upstream agricultural drains to the mainstem San Joaquin River.4. The application of an in situ optical NO3− sensor along with discrete samples provides a view into the fine temporal structure of hydrochemical data and may allow for greater accuracy in pollution assessment.

  9. Modeling pesticide loadings from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT

    Science.gov (United States)

    Chen, H.; Zhang, M.

    2016-12-01

    The Sacramento-San Joaquin Delta is an ecologically rich, hydrologically complex area that serves as the hub of California's water supply. However, pesticides have been routinely detected in the Delta waterways, with concentrations exceeding the benchmark for the protection of aquatic life. Pesticide loadings into the Delta are partially attributed to the San Joaquin watershed, a highly productive agricultural watershed located upstream. Therefore, this study aims to simulate pesticide loadings to the Delta by applying the Soil and Water Assessment Tool (SWAT) model to the San Joaquin watershed, under the support of the USDA-ARS Delta Area-Wide Pest Management Program. Pesticide use patterns in the San Joaquin watershed were characterized by combining the California Pesticide Use Reporting (PUR) database and GIS analysis. Sensitivity/uncertainty analyses and multi-site calibration were performed in the simulation of stream flow, sediment, and pesticide loads along the San Joaquin River. Model performance was evaluated using a combination of graphic and quantitative measures. Preliminary results indicated that stream flow was satisfactorily simulated along the San Joaquin River and the major eastern tributaries, whereas stream flow was less accurately simulated in the western tributaries, which are ephemeral small streams that peak during winter storm events and are mainly fed by irrigation return flow during the growing season. The most sensitive parameters to stream flow were CN2, SOL_AWC, HRU_SLP, SLSUBBSN, SLSOIL, GWQMN and GW_REVAP. Regionalization of parameters is important as the sensitivity of parameters vary significantly spatially. In terms of evaluation metric, NSE tended to overrate model performance when compared to PBIAS. Anticipated results will include (1) pesticide use pattern analysis, (2) calibration and validation of stream flow, sediment, and pesticide loads, and (3) characterization of spatial patterns and temporal trends of pesticide yield.

  10. Changes in sediment and organic carbon accumulation in a highly-disturbed ecosystem: The Sacramento-San Joaquin River Delta (California, USA)

    International Nuclear Information System (INIS)

    Canuel, Elizabeth A.; Lerberg, Elizabeth J.; Dickhut, Rebecca M.; Kuehl, Steven A.; Bianchi, Thomas S.; Wakeham, Stuart G.

    2009-01-01

    We used the Sacramento-San Joaquin River Delta CA (Delta, hereafter) as a model system for understanding how human activities influence the delivery of sediment and total organic carbon (TOC) over the past 50-60 years. Sediment cores were collected from sites within the Delta representing the Sacramento River (SAC), the San Joaquin River (SJR), and Franks Tract (FT), a flooded agricultural tract. A variety of anthropogenic tracers including 137 Cs, total DDE (ΣDDE) and brominated diphenyl ether (BDE) congeners were used to quantify sediment accumulation rates. This information was combined with total organic carbon (TOC) profiles to quantify rates of TOC accumulation. Across the three sites, sediment and TOC accumulation rates were four to eight-fold higher prior to 1972. Changes in sediment and TOC accumulation were coincident with completion of several large reservoirs and increased agriculture and urbanization in the Delta watershed. Radiocarbon content of TOC indicated that much of the carbon delivered to the Delta is 'pre-aged' reflecting processing in the Delta watershed or during transport to the sites rather than an input of predominantly contemporary carbon (e.g., 900-1400 years BP in surface sediments and 2200 yrs BP and 3610 yrs BP at the base of the SJR and FT cores, respectively). Together, these data suggest that human activities have altered the amount and age of TOC accumulating in the Delta since the 1940s.

  11. Longitudinal heterogeneity of flow and heat fluxes in a large lowland river: A study of the San Joaquin River, CA, USA during a large-scale flow experiment

    Science.gov (United States)

    Bray, E. N.; Dunne, T.; Dozier, J.

    2011-12-01

    Systematic downstream variation of channel characteristics, scaled by flow affects the transport and distribution of heat throughout a large river. As water moves through a river channel, streamflow and velocity may fluctuate by orders of magnitude primarily due to channel geometry, slope and resistance to flow, and the time scales of those fluctuations range from days to decades (Constantz et al., 1994; Lundquist and Cayan, 2002; McKerchar and Henderson, 2003). It is well understood that the heat budget of a river is primarily governed by surface exchanges, with the most significant surface flux coming from net shortwave radiation. The absorption of radiation at a given point in a river is determined by the wavelength-dependent index of refraction, expressed by the angle of refraction and the optical depth as a function of physical depth and the absorption coefficient (Dozier, 1980). Few studies consider the influence of hydrologic alteration to the optical properties governing net radiative heat transfer in a large lowland river, yet it is the most significant component of the heat budget and definitive to a river's thermal regime. We seek a physically based model without calibration to incorporate scale-dependent physical processes governing heat and flow dynamics in large rivers, how they change across the longitudinal profile, and how they change under different flow regimes. Longitudinal flow and heat flux analyses require synoptic flow time series from multiple sites along rivers, and few hydrometric networks meet this requirement (Larned et al, 2011). We model the energy budget in a regulated 240-km mainstem reach of the San Joaquin River California, USA equipped with multiple gaging stations from Friant Dam to its confluence with the Merced River during a large-scale flow experiment. We use detailed hydroclimatic observations distributed across the longitudinal gradient creating a non-replicable field experiment of heat fluxes across a range of flow regime

  12. Electrical resistivity investigation of fluvial geomorphology to evaluate potential seepage conduits to agricultural lands along the San Joaquin River, Merced County, California, 2012–13

    Science.gov (United States)

    Groover, Krishangi D.; Burgess, Matthew K.; Howle, James F.; Phillips, Steven P.

    2017-02-08

    Increased flows in the San Joaquin River, part of the San Joaquin River Restoration Program, are designed to help restore fish populations. However, increased seepage losses could result from these higher restoration flows, which could exacerbate existing drainage problems in neighboring agricultural lands and potentially damage crops. Channel deposits of abandoned river meanders that are hydraulically connected to the river could act as seepage conduits, allowing rapid and widespread water-table rise during restoration flows. There is a need to identify the geometry and properties of these channel deposits to assess their role in potential increased seepage effects and to evaluate management alternatives for reducing seepage. Electrical and electromagnetic surface geophysical methods have provided a reliable proxy for lithology in studies of fluvial and hyporheic systems where a sufficient electrical contrast exists between deposits of differing grain size. In this study, direct-current (DC) resistivity was used to measure subsurface resistivity to identify channel deposits and to map their subsurface geometry. The efficacy of this method was assessed by using DC resistivity surveys collected along a reach of the San Joaquin River in Merced County, California, during the summers of 2012 and 2013, in conjunction with borings and associated measurements from a hydraulic profiling tool. Modeled DC resistivity data corresponded with data from cores, hand-auger samples, a hydraulic profiling tool, and aerial photographs, confirming that DC resistivity is effective for differentiating between silt and sand deposits in this setting. Modeled DC resistivity data provided detailed two-dimensional cross-sectional resistivity profiles to a depth of about 20 meters. The distribution of high-resistivity units in these profiles was used as a proxy for identifying areas of high hydraulic conductivity. These data were used subsequently to guide the location and depth of wells

  13. Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

    Science.gov (United States)

    Schoellhamer, David H.; Manning, Andrew J.; Work, Paul A.

    2017-01-01

    Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 34 microcosm experiments indicate that the erosion rate coefficient increased as eroded mass increased, contrary to theory. We believe that small erosion depths, erosion rate coefficient deviation from theory, and visual observation of horizontally varying biota and texture at the sediment surface indicate that erosion cannot solely be a function of depth but must also vary horizontally. We test this hypothesis by developing a simple numerical model that includes horizontal heterogeneity, use it to develop an artificial time series of suspended-sediment concentration (SSC) in an erosion microcosm, then analyze that time series assuming horizontal homogeneity. A shear vane was used to estimate that the horizontal standard deviation of critical shear stress was about 30% of the mean value at a site in the Delta. The numerical model of the erosion microcosm included a normal distribution of initial critical shear stress, a linear increase in critical shear stress with eroded mass, an exponential decrease of erosion rate coefficient with eroded mass, and a stepped increase in applied shear stress. The maximum SSC for each step increased gradually, thus confounding identification of a single well-defined critical shear stress as encountered with the empirical data. Analysis of the artificial SSC time series with the assumption of a homogeneous bed reproduced the original profile of critical shear stress, but the erosion rate coefficient increased with eroded mass, similar to the empirical data. Thus, the numerical experiment confirms the small-depth erosion hypothesis. A linear

  14. Diazinon and chlorpyrifos loads in precipitation and urban and agricultural storm runoff during January and February 2001 in the San Joaquin River basin, California

    Science.gov (United States)

    Zamora, Celia; Kratzer, Charles R.; Majewski, Michael S.; Knifong, Donna L.

    2003-01-01

    The application of diazinon and chlorpyrifos on dormant orchards in 2001 in the San Joaquin River Basin was 24 percent less and 3.2 times more than applications in 2000, respectively. A total of 16 sites were sampled during January and February 2001 storm events: 7 river sites, 8 precipitation sites, and 1 urban storm drain. The seven river sites were sampled weekly during nonstorm periods and more frequently during storm runoff from a total of four storms. The monitoring of storm runoff at a city storm drain in Modesto, California, occurred simultaneously with the collection of precipitation samples from eight sites during a January 2001 storm event. The highest concentrations of diazinon occurred during the storm periods for all 16 sites, and the highest concentrations of chlorpyrifos occurred during weekly nonstorm sampling for the river sites and during the January storm period for the urban storm drain and precipitation sites. A total of 60 samples (41 from river sites, 10 from precipitation sites, and 9 from the storm drain site) had diazinon concentrations greater than 0.08 ?g/L, the concentration being considered by the California Department of Fish and Game as its criterion maximum concentration for the protection of aquatic habitats. A total of 18 samples (2 from river sites, 9 from precipitation sites, and 7 from the storm drain site) exceeded the equivalent California Department of Fish and Game guideline of 0.02 ?g/L for chlorpyrifos. The total diazinon load in the San Joaquin River near Vernalis during January and February 2001 was 23.8 pounds active ingredient; of this amount, 16.9 pounds active ingredient were transported by four storms, 1.06 pounds active ingredient were transported by nonstorm events, and 5.82 pounds active ingredient were considered to be baseline loads. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2001 was 2.17 pounds active ingredient; of this amount, 0.702 pound active

  15. San Joaquin River Up-Stream DO TMDL Project Task 4: MonitoringStudy Interim Task Report #3

    Energy Technology Data Exchange (ETDEWEB)

    Stringfellow, William; Borglin, Sharon; Dahlgren, Randy; Hanlon,Jeremy; Graham, Justin; Burks, Remie; Hutchinson, Kathleen

    2007-03-30

    The purpose of the Dissolved Oxygen Total Maximum Daily LoadProject (DO TMDLProject) is to provide a comprehensive understanding ofthe sources and fate of oxygen consuming materials in the San JoaquinRiver (SJR) watershed between Channel Point and Lander Avenue (upstreamSJR). When completed, this study will provide the stakeholders anunderstanding of the baseline conditions of the basin, provide input foran allocation decision, and provide the stakeholders with a tool formeasuring the impact of any waterquality management program that may beimplemented as part of the DO TMDL process. Previous studies haveidentified algal biomass as the most significant oxygen-demandingsubstance in the DO TMDL Project study-area between of Channel Point andLander Ave onthe SJR. Other oxygen-demanding substances found in theupstream SJR include ammonia and organic carbon from sources other thanalgae. The DO TMDL Project study-area contains municipalities, dairies,wetlands, cattle ranching, irrigated agriculture, and industries thatcould potentially contribute biochemical oxygen demand (BOD) to the SJR.This study is designed to discriminate between algal BOD and othersources of BOD throughout the entire upstream SJR watershed. Algalbiomass is not a conserved substance, but grows and decays in the SJR;hence, characterization of oxygen-demanding substances in the SJR isinherently complicated and requires an integrated effort of extensivemonitoring, scientific study, and modeling. In order to achieve projectobjectives, project activities were divided into a number of Tasks withspecific goals and objectives. In this report, we present the results ofmonitoring and research conducted under Task 4 of the DO TMDL Project.The major objective of Task 4 is to collect sufficient hydrologic (flow)and water quality (WQ) data to characterize the loading of algae, otheroxygen-demanding materials, and nutrients fromindividual tributaries andsub-watersheds of the upstream SJR between Mossdale and

  16. Recent Advances in Understanding Flow Dynamics and Transport of Water-Quality Constituents in the Sacramento–San Joaquin River Delta

    Directory of Open Access Journals (Sweden)

    David H. Schoellhamer

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art1This paper, part of the collection of research comprising the State of Bay–Delta Science 2016, describes advances during the past decade in understanding flow dynamics and how water-quality constituents move within California’s Sacramento–San Joaquin River Delta (Delta. Water-quality constituents include salinity, heat, oxygen, nutrients, contaminants, organic particles, and inorganic particles. These constituents are affected by water diversions and other human manipulations of flow, and they greatly affect the quantity and quality of benthic, pelagic, and intertidal habitat in the Delta. The Pacific Ocean, the Central Valley watershed, human intervention, the atmosphere, and internal biogeochemical processes are all drivers of flow and transport in the Delta. These drivers provide a conceptual framework for presenting recent findings. The tremendous expansion of acoustic and optical instruments deployed in the Delta over the past decade has greatly improved our understanding of how tidal variability affects flow and transport. Sediment is increasingly viewed as a diminishing resource needed to sustain pelagic habitat and tidal marsh, especially as sea level rises. Connections among the watershed, Delta, and San Francisco Bay that have been quantified recently highlight that a landscape view of this system is needed, rather than consideration of each region in isolation. We discuss interactions of multiple drivers and information gaps.

  17. Determination of pesticides associated with suspended sediments in the San Joaquin River, California, USA, using gas chromatography-ion trap mass spectrometry

    Science.gov (United States)

    Bergamaschi, B.A.; Baston, D.S.; Crepeau, K.L.; Kuivila, K.M.

    1999-01-01

    An analytical method useful for the quantification of a range of pesticides and pesticide degradation products associated with suspended sediments was developed by testing a variety of extraction and cleanup schemes. The final extraction and cleanup methods chosen for use are suitable for the quantification of the listed pesticides using gas chromatography-ion trap mass spectrometry and the removal of interfering coextractable organic material found in suspended sediments. Methylene chloride extraction followed by Florisil cleanup proved most effective for separation of coextractives from the pesticide analytes. Removal of elemental sulfur was accomplished with tetrabutylammonium hydrogen sulfite. The suitability of the method for the analysis of a variety of pesticides was evaluated, and the method detection limits (MDLs) were determined (0.1-6.0 ng/g dry weight of sediment) for 21 compounds. Recovery of pesticides dried onto natural sediments averaged 63%. Analysis of duplicate San Joaquin River suspended-sediment samples demonstrated the utility of the method for environmental samples with variability between replicate analyses lower than between environmental samples. Eight of 21 pesticides measured were observed at concentrations ranging from the MDL to more than 80 ng/g dry weight of sediment and exhibited significant temporal variability. Sediment-associated pesticides, therefore, may contribute to the transport of pesticides through aquatic systems and should be studied separately from dissolved pesticides.

  18. Effect of Climate Extremes, Seasonal Change, and Agronomic Practices on Measured Evapotranspiration and CO2 Exchange in Sacramento-San Joaquin River Delta Alfalfa Fields

    Science.gov (United States)

    Clay, J.; Kent, E. R.; Leinfelder-Miles, M.; Paw U, K. T.; Little, C.; Lambert, J. J.

    2017-12-01

    Evapotranspiration and CO2 exchange was measured in five alfalfa fields in the Sacramento-San Joaquin River Delta region from 2016 to 2017 using eddy covariance and surface renewal methods. Seasonal changes of evapotranspiration and CO2 fluxes were compared between 2016, a drought year, and 2017, a high rainfall year. Additionally, changes in evapotranspiration and CO2 flux were investigated across various agronomic considerations, such as irrigation methods (border-check flood and sub-surface), stand life, and herbicide programs. Components of the energy balance, including net radiation, latent heat, ground heat flux, and sensible heat, were evaluated considering correlations to wind speed measured by three sonic anemometers, irrigation frequency, and crop cutting cycle. Comparisons between two different types of radiometers were also carried out. Under drought conditions, we observed higher amounts of evapotranspiration in a field having a stand life of less than two years of age compared to older stands, and in a sub-surface irrigated field compared to flood irrigated fields.

  19. Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Wim J. Kimmerer

    2008-06-01

    Full Text Available Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha and delta smelt (Hypomesus transpacificus to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young. These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15% although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%. The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

  20. San Joaquin Valley Aerosol Health Effects Research Center (SAHERC)

    Data.gov (United States)

    Federal Laboratory Consortium — At the San Joaquin Valley Aerosol Health Effects Center, located at the University of California-Davis, researchers will investigate the properties of particles that...

  1. Paleohydrogeology of the San Joaquin basin, California

    Science.gov (United States)

    Wilson, A.M.; Garven, G.; Boles, J.R.

    1999-01-01

    Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

  2. Using remote sensing to monitor past changes and assess future scenarios for the Sacramento-San Joaquin River Delta waterways, California USA

    Science.gov (United States)

    Santos, Maria J.; Hestir, Erin; Khanna, Shruti; Ustin, Susan L.

    2017-04-01

    Historically, deltas have been extensively affected both by natural processes and human intervention. Thus, understanding drivers, predicting impacts and optimizing solutions to delta problems requires a holistic approach spanning many sectors, disciplines and fields of expertise. Deltas are ideal model systems to understand the effects of the interaction between social and ecological domains, as they face unprecedented disturbances and threats to their biological and ecological sustainability. The challenge for deltas is to meet the goals of supporting biodiversity and ecosystem processes while also provisioning fresh water resources for human use. We provide an overview of the last 150 years of the Sacramento-San Joaquin River delta, where we illustrate the parallel process of an increase in disturbances, by particularly zooming in on the current cascading effects of invasive species on geophysical and biological processes. Using remote sensing data coupled with in situ measurements of water quality, turbidity, and species presence we show how the spread and persistence of aquatic invasive species affects sedimentation processes and ecosystem functioning. Our results show that the interactions between the biological and physical conditions in the Delta affect the trajectory of dominance by native and invasive aquatic plant species. Trends in growth and community characteristics associated with predicted impacts of climate change (sea level rise, warmer temperatures, changes in the hydrograph with high winter and low summer outflows) do not provide simple predictions. Individually, the impact of specific environmental changes on the biological components can be predicted, however it is the complex interactions of biological communities with the suite of physical changes that make predictions uncertain. Systematic monitoring is critical to provide the data needed to document and understand change of these delta systems, and to identify successful adaptation

  3. In the San Joaquin Valley, hardly a sprinkle

    International Nuclear Information System (INIS)

    Holson, L.M.

    1993-01-01

    California has declared its six-year drought over, but in the San Joaquin Valley, center of the state's $18.5 billion agriculture industry, it lives on. The two weeks of strong rain this winter that swelled reservoirs and piled snow on the mountains is only trickling toward the region's nearly 20,000 farms. Federal water officials are under heavy pressure from the Environmental Protection Agency, which wants to improve water quality, and are worried about the plight of endangered fish in the Sacramento River. So, on March 12 they announced they will send farmers only 40% of the water allotments they got before the drought. The rest is being held against possible shortages. For the once-green valley, another year without water has brought many farmers perilously close to extinction

  4. 76 FR 5276 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-01-31

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... protection, Air pollution control, Incorporation by reference, Intergovernmental relations, Nitrogen dioxide...

  5. 76 FR 52623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-08-23

    ... respiratory and cardiovascular disease, decreased lung function, visibility impairment, and damage to... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...

  6. 75 FR 28509 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-05-21

    ..., aggravation of respiratory and cardiovascular disease, decreased lung function, visibility impairment, and... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...

  7. 76 FR 37044 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-06-24

    ... premature mortality, aggravation of respiratory and cardiovascular disease, decreased lung function... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of...

  8. Geological literature on the San Joaquin Valley of California

    Science.gov (United States)

    Maher, J.C.; Trollman, W.M.; Denman, J.M.

    1973-01-01

    The following list of references includes most of the geological literature on the San Joaquin Valley and vicinity in central California (see figure 1) published prior to January 1, 1973. The San Joaquin Valley comprises all or parts of 11 counties -- Alameda, Calaveras, Contra Costa, Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus, and Tulare (figure 2). As a matter of convenient geographical classification the boundaries of the report area have been drawn along county lines, and to include San Benito and Santa Clara Counties on the west and Mariposa and Tuolumne Counties on the east. Therefore, this list of geological literature includes some publications on the Diablo and Temblor Ranges on the west, the Tehachapi Mountains and Mojave Desert on the south, and the Sierra Nevada Foothills and Mountains on the east.

  9. 76 FR 45212 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-07-28

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... proposing to approve San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Rule 3170... the environment. San Joaquin Valley Unified Air Pollution Control District SJVUAPCD is an extreme...

  10. Variation in Spring Nearshore Resident Fish Species Composition and Life Histories in the Lower San Joaquin Watershed and Delta

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2006-09-01

    Full Text Available Providing freshwater to human populations while protecting or rehabilitating ecosystem health is a significant challenge to water resource managers and requires accurate knowledge of aquatic resources. Previous studies of fish assemblages in the San Francisco Estuary and watershed have focused on specific habitat types, water bodies, or geographic subregions. In this study, we use seining data from two monitoring programs to provide an integrated view of spring nearshore resident fish species composition and life history characteristics in five regions: the San Joaquin River, the upper Sacramento River, the lower Sacramento River, the northern Sacramento-San Joaquin Delta (North Delta, and the Interior Delta. Data for the period March-May from 1994 to 2002, showed that spring species composition of the San Joaquin River was very different from the other four regions. Total catch in the San Joaquin River was dominated by small, short-lived batch spawning alien species (93%, particularly red shiner Cyprinella lutrensis (>75% of total catch. The upper and lower Sacramento River were very similar in species composition and life history characteristics and less dominated by alien fish (

  11. 76 FR 9709 - Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

    Science.gov (United States)

    2011-02-22

    ... Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary AGENCY... the San Francisco Bay/ Sacramento-San Joaquin Delta Estuary (Bay Delta Estuary) in California. EPA is... programs to address recent significant declines in multiple aquatic species in the Bay Delta Estuary. EPA...

  12. Timber resource statistics for the San Joaquin and southern resource areas of California.

    Science.gov (United States)

    Karen L. Waddell; Patricia M. Bassett

    1997-01-01

    This report is a summary of timber resource statistics for the San Joaquin and Southern Resource Areas of California, which include Alpine, Amador, Calaveras, Fresno, Imperial, Inyo, Kern, Kings, Los Angeles, Madera, Mariposa, Merced, Mono, Orange, Riverside, San Bernardino, San Diego, San Joaquin, Stanislaus, Tulare, and Tuolumne Counties. Data were collected as part...

  13. Selenium and other elements in freshwater fishes from the irrigated San Joaquin Valley, California

    Science.gov (United States)

    Saiki, M.K.; Jennings, M.R.; May, T.W.

    1992-01-01

    Arsenic (As), chromium (Cr), mercury (Hg), and selenium (Se) were measured in composite whole-body samples of five fishes — bluegill (Lepomis macrochirus), common carp (Cyprinus carpio), mosquitofish (Gambusia affinis), largemouth bass (Micropterus salmoides), and Sacramento blackfish (Orthodon microlepidotus) — from the San Joaquin River system to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage. Except for Cr, the concentrations of these elements in fishes from one or more sites were elevated; however, only Se approached concentrations that may adversely affect survival, growth, or reproduction in warm water fishes. Moreover, only Se among the four measured elements exhibited a geographic (spatial) pattern that coincided with known inflows of tile drainage to the San Joaquin River and its tributaries. Historical data from the Grassland Water District (Grasslands; a region exposed to concentrated tile drainage) suggested that concentrations of Se in fishes were at maximum during or shortly after 1984 and have been slightly lower since then. The recent decline of Se concentrations in fishes from the Grasslands could be temporary if additional acreages of irrigated lands in this portion of the San Joaquin Valley must be tile-drained to protect agricultural crops from rising groundwater tables.

  14. Groundwater quality in the western San Joaquin Valley, California

    Science.gov (United States)

    Fram, Miranda S.

    2017-06-09

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Western San Joaquin Valley is one of the study units being evaluated. 

  15. Examining Dimethyl Sulfide Emissions in California's San Joaquin Valley

    Science.gov (United States)

    Huber, D.; Hughes, S.; Blake, D. R.

    2017-12-01

    Dimethyl Sulfide (DMS) is a sulfur-containing compound that leads to the formation of aerosols which can lead to the formation of haze and fog. Whole air samples were collected on board the NASA C-23 Sherpa aircraft during the 2017 Student Airborne Research Program (SARP) over dairies and agricultural fields in the San Joaquin Valley. Analysis of the samples indicate average DMS concentrations of 23 ± 9 pptv, with a maximum concentration of 49 pptv. When compared with DMS concentrations from previous SARP missions (2009-2016), 2017 by far had the highest frequency of elevated DMS in this region. For this study, agricultural productivity of this region was analyzed to determine whether land use could be contributing to the elevated DMS. Top down and bottom up analysis of agriculture and dairies were used to determine emission rates of DMS in the San Joaquin Valley. Correlations to methane and ethanol were used to determine that DMS emissions were strongly linked to dairies, and resulted in R2 values of 0.61 and 0.43, respectively. These values indicate a strong correlation between dairies and DMS emissions. Combined with NOAA HySPLIT back trajectory data and analysis of ground air samples, results suggest that the contribution of dairies to annual DMS emissions in the San Joaquin Valley exceeds those from corn and alfalfa production.

  16. 75 FR 1715 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-01-13

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVAPCD) portion of the...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

  17. 78 FR 53113 - Approval and Promulgation of Implementation Plans; California; San Joaquin Valley; Contingency...

    Science.gov (United States)

    2013-08-28

    ...] Approval and Promulgation of Implementation Plans; California; San Joaquin Valley; Contingency Measures for... California to address Clean Air Act nonattainment area contingency measure requirements for the 1997 annual... Air Act Requirements for Contingency Measures III. Review of the Submitted San Joaquin Valley PM 2.5...

  18. 76 FR 56132 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-12

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... did the State submit? B. Are there other versions of this rule? C. What is the purpose of the...

  19. 77 FR 214 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-01-04

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approval of revisions to the San Joaquin Valley Air Pollution Control District (SJVUAPCD) portion of the... used by the California Air Resources Board and air districts for evaluating air pollution control...

  20. 76 FR 47076 - Revision to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-08-04

    ... California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District AGENCY... the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

  1. 76 FR 56134 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-12

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

  2. 75 FR 60623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-10-01

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approval and limited disapproval of revisions to the San Joaquin Valley Unified Air Pollution Control... 30, 2008) \\2\\; and Ventura County Air Pollution Control District (VCAPCD) Rule 74.15 (as amended...

  3. 75 FR 57862 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-09-23

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

  4. 76 FR 69135 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-11-08

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  5. 76 FR 56706 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-14

    ... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Intergovernmental...

  6. Adaptive Management Methods to Protect the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, David

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  7. Chemical analyses for selected wells in San Joaquin County and part of Contra Costa County, California

    Science.gov (United States)

    Keeter, Gail L.

    1980-01-01

    The study area of this report includes the eastern valley area of Contra Costa County and all of San Joaquin County, an area of approximately 1,600 square miles in the northern part of the San Joaquin Valley, Calif. Between December 1977 and December 1978, 1,489 wells were selectively canvassed. During May and June in 1978 and 1979, water samples were collected for chemical analysis from 321 of these wells. Field determinations of alkalinity, conductance, pH, and temperature were made, and individual constituents were analyzed. This report is the fourth in a series of baseline data reports on wells in the Sacramento and San Joaquin Valleys. (USGS)

  8. 2007 California Department of Water Resources Topographic LiDAR: San Joaquin Delta

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are from LIDAR flights of the Sacramento-San Joaquin Delta conducted during late January and February of 2007. The work was conducted under contract...

  9. 76 FR 38340 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-06-30

    ... also harm human health and the environment by causing, among other things, premature mortality, aggravation of respiratory and cardiovascular disease, visibility impairment, and damage to vegetation and... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District...

  10. Spatial trends and impairment assessment of mercury in sport fish in the Sacramento-San Joaquin Delta watershed

    International Nuclear Information System (INIS)

    Melwani, A.R.; Bezalel, S.N.; Hunt, J.A.; Grenier, J.L.; Ichikawa, G.; Heim, W.; Bonnema, A.; Foe, C.; Slotton, D.G.; Davis, J.A.

    2009-01-01

    A three-year study was conducted to examine mercury in sport fish from the Sacramento-San Joaquin Delta. More than 4000 fish from 31 species were collected and analyzed for total mercury in individual muscle filets. Largemouth bass and striped bass were the most contaminated, averaging 0.40 μg/g, while redear sunfish, bluegill and rainbow trout exhibited the lowest (<0.15 μg/g) concentrations. Spatial variation in mercury was evaluated with an analysis of covariance model, which accounted for variability due to fish size and regional hydrology. Significant regional differences in mercury were apparent in size-standardized largemouth bass, with concentrations on the Cosumnes and Mokelumne rivers significantly higher than the central and western Delta. Significant prey-predator mercury correlations were also apparent, which may explain a significant proportion of the spatial variation in the watershed. - Regional differences in sport fish mercury were found in the Sacramento-San Joaquin Delta.

  11. Modeling pesticide diuron loading from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT.

    Science.gov (United States)

    Chen, Huajin; Luo, Yuzhou; Potter, Christopher; Moran, Patrick J; Grieneisen, Michael L; Zhang, Minghua

    2017-09-15

    Quantifying pesticide loading into the Sacramento-San Joaquin Delta of northern California is critical for water quality management in the region, and potentially useful for biological weed control planning. In this study, the Soil and Water Assessment Tool (SWAT) was applied to model streamflow, sediment, and pesticide diuron loading in the San Joaquin watershed, a major contributing area to the elevated pesticide levels in the downstream Delta. The Sequential Uncertainty Fitting version 2 (SUFI-2) algorithm was employed to perform calibration and uncertainty analysis. A combination of performance measures (PMs) and standardized performance evaluation criteria (PEC) was applied to evaluate model performance, while prediction uncertainty was quantified by 95% prediction uncertainty band (95PPU). Results showed that streamflow simulation was at least "satisfactory" at most stations, with more than 50% of the observed data bracketed by the 95PPU. Sediment simulation was rated as at least "satisfactory" based on two PMs, and diuron simulation was judged as "good" by all PMs. The 95PPU of sediment and diuron bracketed about 40% and 30% of the observed data, respectively. Significant correlations were observed between the diuron loads, and precipitation, streamflow, and the current and antecedent pesticide use. Results also showed that the majority (>70%) of agricultural diuron was transported during winter months, when direct exposure of biocontrol agents to diuron runoff is limited. However, exposure in the dry season could be a concern because diuron is relatively persistent in aquatic system. This study not only provides valuable information for the development of biological weed control plan in the Delta, but also serves as a foundation for the continued research on calibration, evaluation, and uncertainty analysis of spatially distributed, physically based hydrologic models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Evaluating the Aquatic Habitat Potential of Flooded Polders in the Sacramento-San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    John R. Durand

    2017-12-01

    Full Text Available https://doi.org/10.15447/sfews.2017v15iss4art4Large tracts of land in the Sacramento-San Joaquin Delta are subsided due to agricultural practices, creating polders up to 10 m below sea level that are vulnerable to flooding. As protective dikes breach, these become shallow, open water habitats that will not resemble any historical state. I investigated physical and biotic drivers of novel flooded polder habitat, using a Native Species Benefit Index (NSBI to predict the nature of future Delta ecosystems. Results suggest that flooded polders in the north Delta will have the ecology and fish community composition of a tidal river plain, those in the Cache-Lindsey Complex will have that of a tidal backwater, those in the confluence of the Sacramento and San Joaquin Rivers a brackish estuary, and those in the south Delta a fresh water lake. Flooded east-side Delta polders will likely be a transitional zone between south Delta lake-like ecosystems and north Delta tidal river plains. I compared each regional zone with the limited available literature and data on local fish assemblies to find support for NSBI predictions. Because flood probabilities and repair prioritization analyses suggest that polders in the south Delta are most likely to flood and be abandoned, without extensive intervention, much of the Delta will become a freshwater lake ecosystem, dominated by alien species. Proactive management of flooded tracts will nearly always hedge risks, save money and offer more functional habitats in the future; however, without proper immediate incentives, it will be difficult to encourage strong management practices.

  13. Groundwater quality in the Madera and Chowchilla subbasins of the San Joaquin Valley, California

    Science.gov (United States)

    Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

    2013-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The Madera and Chowchilla subbasins of the San Joaquin Valley constitute one of the study units being evaluated. The Madera-Chowchilla study unit is about 860 square miles and consists of the Madera and Chowchilla groundwater subbasins of the San Joaquin Valley Basin (California Department of Water Resources, 2003; Shelton and others, 2009). The study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 11 to 15 inches, most of which occurs between November and February. The main surface-water features in the study unit are the San Joaquin, Fresno, and Chowchilla Rivers, and the Madera and Chowchilla canals. Land use in the study unit is about 69 percent (%) agricultural, 28% natural (mainly grasslands), and 3% urban. The primary crops are orchards and vineyards. The largest urban area is the city of Madera. The primary aquifer system is defined as those parts of the aquifer corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. In the Madera-Chowchilla study unit, these wells typically are drilled to depths between 200 and 800 feet, consist of a solid casing from land surface to a depth of about 140 to 400 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer system. The primary aquifer system in the study unit consists of Quaternary-age alluvial-fan and fluvial deposits that were formed by the rivers draining the Sierra Nevada. Sediments consist of gravels, sands

  14. Effects of the proposed California WaterFix North Delta Diversion on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento-San Joaquin River Delta, northern California

    Science.gov (United States)

    Perry, Russell W.; Pope, Adam C.

    2018-05-11

    The California Department of Water Resources and Bureau of Reclamation propose new water intake facilities on the Sacramento River in northern California that would convey some of the water for export to areas south of the Sacramento-San Joaquin River Delta (hereinafter referred to as the Delta) through tunnels rather than through the Delta. The collection of water intakes, tunnels, pumping facilities, associated structures, and proposed operations are collectively referred to as California WaterFix. The water intake facilities, hereinafter referred to as the North Delta Diversion (NDD), are proposed to be located on the Sacramento River downstream of the city of Sacramento and upstream of the first major river junction where Sutter Slough branches from the Sacramento River. The NDD can divert a maximum discharge of 9,000 cubic feet per second (ft3 /s) from the Sacramento River, which reduces the amount of Sacramento River inflow into the Delta. In this report, we conduct four analyses to investigate the effect of the NDD and its proposed operation on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha). All analyses used the results of a Bayesian survival model that allowed us to simulate travel time, migration routing, and survival of juvenile Chinook salmon migrating through the Delta in response to NDD operations, which affected both inflows to the Delta and operation of the Delta Cross Channel (DCC). For the first analysis, we evaluated the effect of the NDD bypass rules on salmon survival. The NDD bypass rules are a set of operational rule curves designed to provide adaptive levels of fish protection by defining allowable diversion rates as a function of (1) Sacramento River discharge as measured at Freeport, and (2) time of year when endangered runs requiring the most protection are present. We determined that all bypass rule curves except constant low-level pumping (maximum diversion of 900 ft3 /s) could cause a sizeable decrease in survival by as

  15. Is it restoration or reconciliation? California's experience restoring the Sacramento - San Joaquin River Delta provides lessons learned and pathways forward to sustain critical ecosystem functions and services in a highly managed riverine delta.

    Science.gov (United States)

    Viers, J. H.; Kelsey, R.

    2014-12-01

    Reconciling the needs of nature and people in California's Sacramento - San Joaquin River Delta represents one of the most critical ecosystem management imperatives in western North America. Over 150 years the Delta has been managed for near-term human benefits and in the process 95% of riverine and deltaic wetlands have been lost throughout the region. Despite extensive land conversion and alteration of hydrological and physical processes, the Delta remains important habitat for migratory birds and is home to over 60% of California's native fish species. It is also the waterwheel for the state's vast water distribution network and is maintained by a system of constructed levees that are at risk from catastrophic failure due to sea level rise, floods, and/or seismic activity. Such a collapse would have dire consequences for > 25M humans and world's 10th largest economy that depend on its freshwater. Thus, the ultimate cost of this ecosystem alteration and simplification is a riverscape that is no longer reliable for nature or people. For 30 years, attempts to 'restore' Delta ecosystems and improve reliability have met with mixed results. For example, reconnection of floodplains to floodwaters has resulted in improved ecological health for native fishes and recharge to localized aquifers. Uncoordinated releases of discharges below dams, however, have resulted in diminished water quality and populations of indicator species. Attempts to create wildlife friendly farms have been countered by an increase in perennial agriculture and commensurate increases in irrigation water demand. From these lessons learned, we demonstrate three key components of a reconciled Delta that will be necessary in the future: 1) full restoration of critical habitats, reconnecting land and water to rebuild ecosystem function; 2) landscape redesign, incorporating natural and engineered infrastructure to create a biologically diverse, resilient landscape to support both agriculture and natural

  16. Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA)

    Science.gov (United States)

    Spencer, R.G.M.; Pellerin, B.A.; Bergamaschi, B.A.; Downing, B.D.; Kraus, T.E.C.; Smart, D.R.; Dahlgren, R.A.; Hernes, P.J.

    2007-01-01

    Dissolved organic matter (DOM) concentration and composition in riverine and stream systems are known to vary with hydrological and productivity cycles over the annual and interannual time scales. Rivers are commonly perceived as homogeneous with respect to DOM concentration and composition, particularly under steady flow conditions over short time periods. However, few studies have evaluated the impact of short term variability ( monitored and serves to increase our understanding of its processing and fundamental role in the aquatic environment. Copyright ?? 2007 John Wiley & Sons, Ltd.

  17. Climate change and other stressors change modeled population size and hybridization potential for San Joaquin kit fox

    Science.gov (United States)

    The San Joaquin kit fox was once widely distributed across the southern San Joaquin Valley, but agriculture and development have replaced much of the endangered subspecies’ habitat. We modeled impacts of climate change, land-use change, and rodenticide exposure on kit fox p...

  18. 76 FR 59254 - Interim Final Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-26

    ... Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

  19. 76 FR 56116 - Interim Final Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-12

    ... Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District... Part 52 Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental...

  20. 76 FR 56114 - Interim Final Determination to Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-09-12

    ... Determination to Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District... Part 52 Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental...

  1. Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA)

    Science.gov (United States)

    Spencer, R.G.M.; Pellerin, B.A.; Bergamaschi, B.A.; Downing, B.D.; Kraus, T.E.C.; Smart, D.R.; Dahlgren, R.A.; Hernes, P.J.

    2007-01-01

    Dissolved organic matter (DOM) concentration and composition in riverine and stream systems are known to vary with hydrological and productivity cycles over the annual and interannual time scales. Rivers are commonly perceived as homogeneous with respect to DOM concentration and composition, particularly under steady flow conditions over short time periods. However, few studies have evaluated the impact of short term variability ( DOC) measurement alone. The in situ optical measurements described in this study clearly showed for the first time diurnal variations in DOM measurements, which have previously been related to both composition and concentration, even though diurnal changes were not well reflected in bulk DOC concentrations. An apparent asynchronous trend of DOM absorbance and chlorophyll-a in comparison to chromophoric dissolved organic matter (CDOM) fluorescence and spectral slope S290-350 suggests that no one specific CDOM spectrophotometric measurement explains absolutely DOM diurnal variation in this system; the measurement of multiple optical parameters is therefore recommended. The observed diurnal changes in DOM composition, measured by in situ optical instrumentation likely reflect both photochemical and biologically-mediated processes. The results of this study highlight that short-term variability in DOM composition may complicate trends for studies aiming to distinguish different DOM sources in riverine systems and emphasizes the importance of sampling specific study sites to be compared at the same time of day. The utilization of in situ optical technology allows short-term variability in DOM dynamics to be monitored and serves to increase our understanding of its processing and fundamental role in the aquatic environment. Copyright ?? 2007 John Wiley & Sons, Ltd.

  2. Factors influencing the biogeochemistry of sedimentary carbon and phosphorus in the Sacramento-San Joaquin Delta

    Science.gov (United States)

    Nilsen, E.B.; Delaney, M.L.

    2005-01-01

    This study characterizes organic carbon (Corganic) and phosphorus (P) geochemistry in surface sediments of the Sacramento-San Joaquin Delta, California. Sediment cores were collected from five sites on a sample transect from the edge of the San Francisco Bay eastward to the freshwater Consumnes River. The top 8 cm of each core were analyzed (in 1-cm intervals) for Corganic, four P fractions, and redox-sensitive trace metals (uranium and manganese). Sedimentary Corganic concentrations and Corganic:P ratios decreased, while reactive P concentrations increased moving inland in the Delta. The fraction of total P represented by organic P increased inland, while that of authigenic P was higher bayward than inland reflecting increased diagenetic alteration of organic matter toward the bayward end of the transect. The redox indicator metals are consistent with decreasing sedimentary suboxia inland. The distribution of P fractions and C:P ratios reflect the presence of relatively labile organic matter in upstream surface sediments. Sediment C and P geochemistry is influenced by site-specific particulate organic matter sources, the sorptive power of the sedimentary material present, physical forcing, and early diagenetic transformations presumably driven by Corganic oxidation. ?? 2005 Estuarine Research Federation.

  3. Invasive Plants - San Joaquin River [ds624

    Data.gov (United States)

    California Natural Resource Agency — The purpose of this work is to estimate the occurrence, distribution, approximate locations, and abundance of red sesbania (Sesbania punicea) and four other major...

  4. Vertebrate fauna of the San Joaquin Experimental Range, California: a checklist

    Science.gov (United States)

    Thomas F. Newman; Don A. Duncan

    1973-01-01

    This report updates an earlier checklist, published in 1955, of vertebrate fauna found on the San Joaquin Experimental Range, in Madera County, California. Nineteen new species have been recorded since 1955. This report records the occurrences of seven fish, eight amphibians, 19 reptiles, 38 mammals, and 149 buds. References to research on individual species are...

  5. 77 FR 745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-01-06

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0547; FRL-9480-1] Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Correction In rule document 2011-33660 appearing on pages 214-217 in the issue of Wednesday, January 4, 2012, make the following corrections...

  6. The "Roar of Chatter" in the Library at San Joaquin Delta College. Research Project.

    Science.gov (United States)

    Evans, Richard B.

    Quiet signs and verbal cautioning by library staff do not decrease library noise levels as revealed by two tests using sound measuring equipment at San Joaquin Delta College. The levels in fact increased, confirming previous opinions that signs and staff intervention have little effect on patron behavior. Test methods, data, and five references…

  7. 76 FR 35167 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-06-16

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0312; FRL-9319-8] Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Intergovernmental relations...

  8. Proposed Approval of California Air Plan Revision; San Joaquin Valley Unified Air Pollution Control District; Reasonably Available Control Technology Demonstration

    Science.gov (United States)

    EPA isproposing to approve revisions to the SJVUAPCD portion of the California SIP applying to the San Joaquin Valley of California concerning demonstration regarding RACT requirements for the 2008 8-hour ozone National Ambient Air Quality Standard (NAAQS)

  9. 76 FR 69895 - Approval and Promulgation of Implementation Plans; California; 2008 San Joaquin Valley PM2.5

    Science.gov (United States)

    2011-11-09

    ... Board, 1001 I Street, Sacramento, California 95812 San Joaquin Valley Air Pollution Control District.../reasonably available control technology demonstration, reasonable further progress demonstration, attainment... 5, 2015 and approving commitments to measures and reductions by the SJV Unified Air Pollution...

  10. Recreation Value of Water to Wetlands in the San Joaquin Valley: Linked Multinomial Logit and Count Data Trip Frequency Models

    Science.gov (United States)

    Creel, Michael; Loomis, John

    1992-10-01

    The recreational benefits from providing increased quantities of water to wildlife and fisheries habitats is estimated using linked multinomial logit site selection models and count data trip frequency models. The study encompasses waterfowl hunting, fishing and wildlife viewing at 14 recreational resources in the San Joaquin Valley, including the National Wildlife Refuges, the State Wildlife Management Areas, and six river destinations. The economic benefits of increasing water supplies to wildlife refuges were also examined by using the estimated models to predict changing patterns of site selection and overall participation due to increases in water allocations. Estimates of the dollar value per acre foot of water are calculated for increases in water to refuges. The resulting model is a flexible and useful tool for estimating the economic benefits of alternative water allocation policies for wildlife habitat and rivers.

  11. Improving Aquatic Plant Management in the California Sacramento-San Joaquin Delta

    Science.gov (United States)

    Bubenheim, David L.; Potter, Chris

    2018-01-01

    Management of aquatic weeds in complex watersheds and river systems present many challenges to assessment, planning and implementation of management practices for floating and submerged aquatic invasive plants. The Delta Region Areawide Aquatic Weed Project (DRAAWP), a USDA sponsored area-wide project, is working to enhance planning, decision-making and operational efficiency in the California Sacramento-San Joaquin Delta. Satellite and airborne remote sensing are used map (area coverage and biomass), direct operations, and assess management impacts on plant communities. Archived satellite records going are used to review results from previous climate and management events and aide in developing long-term strategies. Modeling at local and watershed scales provides insight into land-use effects on water quality. Plant growth models informed by remote sensing are being applied spatially across the Delta to balance location and type of aquatic plant, growth response to altered environments, phenology, environmental regulations, and economics in selection of management practices. Initial utilization of remote sensing tools developed for mapping of aquatic invasive weeds improved operational efficiency by focusing limited chemical use to strategic areas with high plant-control impact and incorporating mechanical harvesting when chemical use is restricted. These assessment methods provide a comprehensive and quantitative view of aquatic invasive plants communities in the California Delta, both spatial and temporal, informed by ecological understanding with the objective of improving management and assessment effectiveness.

  12. Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

    2013-01-01

    Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

  13. Trends in nutrient concentrations, loads, and yields in streams in the Sacramento, San Joaquin, and Santa Ana Basins, California, 1975-2004

    Science.gov (United States)

    Kratzer, Charles R.; Kent, Robert; Seleh, Dina K.; Knifong, Donna L.; Dileanis, Peter D.; Orlando, James L.

    2011-01-01

    A comprehensive database was assembled for the Sacramento, San Joaquin, and Santa Ana Basins in California on nutrient concentrations, flows, and point and nonpoint sources of nutrients for 1975-2004. Most of the data on nutrient concentrations (nitrate, ammonia, total nitrogen, orthophosphate, and total phosphorus) were from the U.S. Geological Survey's National Water Information System database (35.2 percent), the California Department of Water Resources (21.9 percent), the University of California at Davis (21.6 percent), and the U.S. Environmental Protection Agency's STOrage and RETrieval database (20.0 percent). Point-source discharges accounted for less than 1 percent of river flows in the Sacramento and San Joaquin Rivers, but accounted for close to 80 percent of the nonstorm flow in the Santa Ana River. Point sources accounted for 4 and 7 percent of the total nitrogen and total phosphorus loads, respectively, in the Sacramento River at Freeport for 1985-2004. Point sources accounted for 8 and 17 percent of the total nitrogen and total phosphorus loads, respectively, in the San Joaquin River near Vernalis for 1985-2004. The volume of wastewater discharged into the Santa Ana River increased almost three-fold over the study period. However, due to improvements in wastewater treatment, the total nitrogen load to the Santa Ana River from point sources in 2004 was approximately the same as in 1975 and the total phosphorus load in 2004 was less than in 1975. Nonpoint sources of nutrients estimated in this study included atmospheric deposition, fertilizer application, manure production, and tile drainage. The estimated dry deposition of nitrogen exceeded wet deposition in the Sacramento and San Joaquin Valleys and in the basin area of the Santa Ana Basin, with ratios of dry to wet deposition of 1.7, 2.8, and 9.8, respectively. Fertilizer application increased appreciably from 1987 to 2004 in all three California basins, although manure production increased in the

  14. 75 FR 24408 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-05-05

    ...EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). These revisions were proposed in the Federal Register on January 22, 2010 and concern oxides of nitrogen (NOx) emissions from residential water heaters. We are approving a local rule that regulates this emission source under the Clean Air Act as amended in 1990 (CAA or the Act).

  15. 77 FR 35327 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-06-13

    ...EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). These revisions concern volatile organic compound (VOC) emissions from the manufacture of polystyrene, polyethylene, and polypropylene products. We are approving a local rule that regulates these emission sources under the Clean Air Act (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

  16. 77 FR 66548 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-11-06

    ...EPA is approving revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). This action was proposed in the Federal Register on April 26, 2012 and concerns oxides of nitrogen (NOX) from solid fuel fired boilers. We are approving a local rule that regulates these emission sources under the Clean Air Act (CAA or the Act).

  17. 75 FR 10690 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2010-03-09

    ...EPA is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). These revisions were proposed in the Federal Register on December 18, 2009 and concern reduction of animal matter and volatile organic compound (VOC) emissions from crude oil production, cutback asphalt, and petroleum solvent dry cleaning. We are approving local rules that regulate these emission sources under the Clean Air Act as amended in 1990 (CAA or the Act).

  18. 77 FR 24883 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-04-26

    ...EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). These revisions concern oxides of nitrogen (NOX) from solid fuel fired boilers, steam generators and process heaters. We are approving a local rule that regulates these emission sources under the Clean Air Act as amended in 1990 (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

  19. 77 FR 35329 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-06-13

    ...EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). These revisions concern volatile organic compound (VOC) emissions from crude oil production sumps and refinery wastewater separators. We are approving local rules that regulate these emission sources under the Clean Air Act as amended in 1990 (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

  20. Determination of bench-mark elevations at Bethel Island and vicinity, Contra Costa and San Joaquin counties, California, 1987

    Science.gov (United States)

    Blodgett, J.C.; Ikehara, M.E.; McCaffrey, William F.

    1988-01-01

    Elevations of 49 bench marks in the southwestern part of the Sacramento-San Joaquin River Delta were determined during October and November 1987. A total of 58 miles of level lines were run in the vicinity of Bethel Island and the community of Discovery Bay. The datum of these surveys is based on a National Geodetic Survey bench mark T934 situated on bedrock 10.5 mi east of Mount Diablo and near Marsh Creek Reservoir. The accuracy of these levels, based on National Geodetic Survey standards, was of first, second, and third order, depending on the various segments surveyed. Several bench marks were noted as possibly being stable, but most show evidence of instability. (USGS)

  1. Distribution and movements of female northern pintails radiotagged in San Joaquin Valley, California

    Science.gov (United States)

    Fleskes, Joseph P.; Jarvis, Robert L.; Gilmer, David S.

    2002-01-01

    To improve understanding of northern pintail (Anas acuta) distribution in central California (CCA), we radiotagged 191 Hatch-Year (HY) and 228 After-Hatch-Year (AHY) female northern pintails during late August-early October, 1991-1993, in the San Joaquin Valley (SJV) and studied their movements through March each year. Nearly all (94.3%) wintered in CCA, but 5.7% went to southern California, Mexico, or unknown areas; all that went south left before hunting season. Of the 395 radiotagged pintails that wintered in CCA, 83% flew from the SJV north to other CCA areas (i.e., Sacramento Valley [SACV], Sacramento-San Joaquin River Delta [Delta], Suisun Marsh, San Francisco Bay) during September-January; most went during December. Movements coincid- ed with start of hunting seasons and were related to pintail age, mass, capture location, study year, and weather. Among pintails with less than average mass, AHY individuals tended to leave the SJV earlier than HY individuals. Weekly distribution was similar among capture locations and years but a greater percentage of pintails radiotagged in Tulare Basin (south part of SJV) were known to have (10.3% vs. 0.9%) or probably (13.8% vs. 4.6%) wintered south of CCA than pintails radiotagged in northern SJV areas (i.e., Grassland Ecological Area [EA] and Mendota Wildlife Area [WA]). Also, a greater percentage of SJV pintails went to other CCA areas before hunting season in the drought year of 1991-1992 than later years (10% vs. 3-5%). The percent of radiotagged pintails from Grass- land EA known to have gone south of CCA also was greater during 1991-1992 than later years (2% vs. 0%), but both the known (19% vs. 4%) and probable (23% vs. 12%) percent from Tulare Basin that went south was greatest during 1993-1994, when availability of flooded fields there was lowest. The probability of pintails leaving the SJV was 57% (95% CI = 8-127%) greater on days with than without rain, and more movements per bird out of SJV occurred in years

  2. Adaptive Management Using Remote Sensing and Ecosystem Modeling in Response to Climate Variability and Invasive Aquatic Plants for the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, David; Potter, Christopher; Zhang, Minghua; Madsen, John

    2017-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply and supports important ecosystem services, agriculture, and communities in Northern to Southern California. Expansion of invasive aquatic plants in the Delta coupled with impacts of changing climate and long-term drought is detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California to develop science-based, adaptive-management strategies for invasive aquatic plant in the Sacramento-San Joaquin Delta. Specific mapping tools developed utilizing satellite and airborne platforms provide regular assessments of population dynamics on a landscape scale and support both strategic planning and operational decision making for resource managers. San Joaquin and Sacramento River watersheds water quality input to the Delta is modeled using the Soil-Water Assessment Tool (SWAT) and a modified SWAT tool has been customized to account for unique landscape and management of agricultural water supply and drainage within the Delta. Environmental response models for growth of invasive aquatic weeds are being parameterized and coupled with spatial distribution/biomass density mapping and water quality to study ecosystem response to climate and aquatic plant management practices. On the water validation and operational utilization of these tools by management agencies and how they are improving decision making, management effectiveness and efficiency will be discussed. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and water resource managers make science-informed decisions regarding management and outcomes.

  3. Adaptive Management Using Remote Sensing and Ecosystem Modeling in Response to Climate Variability and Invasive Aquatic Plants for the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, D.; Potter, C. S.; Zhang, M.; Madsen, J.

    2017-12-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply and supports important ecosystem services, agriculture, and communities in Northern and Southern California. Expansion of invasive aquatic plants in the Delta coupled with impacts of changing climate and long-term drought is detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California to develop science-based, adaptive-management strategies for invasive aquatic plant management in the California Sacramento-San Joaquin Delta. Specific mapping tools developed utilizing satellite and airborne platforms provide regular assessments of population dynamics on a landscape scale and support both strategic planning and operational decision making for resource managers. San Joaquin and Sacramento River watersheds water quality input to the Delta is modeled using the Soil-Water Assessment Tool (SWAT) and a modified SWAT tool has been customized to account for unique landscape and management of agricultural water supply and drainage within the Delta. Environmental response models for growth of invasive aquatic weeds are being parameterized and coupled with spatial distribution/biomass density mapping and water quality to study ecosystem response to climate and aquatic plant management practices. On the water validation and operational utilization of these tools by management agencies and how they improve decision making, management effectiveness and efficiency will be discussed. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and water resource managers make science-informed decisions regarding management and outcomes.

  4. PEAT ACCRETION HISTORIES DURING THE PAST 6000 YEARS IN MARSHES OF THE SACRAMENTO - SAN JOAQUIN DELTA, CALIFORNIA, USA

    Energy Technology Data Exchange (ETDEWEB)

    Drexler, J Z; de Fontaine, C S; Brown, T A

    2009-07-20

    Peat cores were collected in 4 remnant marsh islands and 4 drained, farmed islands throughout the Sacramento - San Joaquin Delta of California in order to characterize the peat accretion history of this region. Radiocarbon age determination of marsh macrofossils at both marsh and farmed islands showed that marshes in the central and western Delta started forming between 6030 and 6790 cal yr BP. Age-depth models for three marshes were constructed using cubic smooth spline regression models. The resulting spline fit models were used to estimate peat accretion histories for the marshes. Estimated accretion rates range from 0.03 to 0.49 cm yr{sup -1} for the marsh sites. The highest accretion rates are at Browns Island, a marsh at the confluence of the Sacramento and San Joaquin rivers. Porosity was examined in the peat core from Franks Wetland, one of the remnant marsh sites. Porosity was greater than 90% and changed little with depth indicating that autocompaction was not an important process in the peat column. The mean contribution of organic matter to soil volume at the marsh sites ranges from 6.15 to 9.25% with little variability. In contrast, the mean contribution of inorganic matter to soil volume ranges from 1.40 to 8.45% with much greater variability, especially in sites situated in main channels. These results suggest that marshes in the Delta can be viewed as largely autochthonous vs. allochthonous in character. Autochthonous sites are largely removed from watershed processes, such as sediment deposition and scour, and are dominated by organic production. Allochthonous sites have greater fluctuations in accretion rates due to the variability of inorganic inputs from the watershed. A comparison of estimated vertical accretion rates with 20th century rates of global sea-level rise shows that currently marshes are maintaining their positions in the tidal frame, yet this offers little assurance of sustainability under scenarios of increased sea-level rise in

  5. 234U/238U and δ87Sr in peat as tracers of paleosalinity in the Sacramento-San Joaquin Delta of California, USA

    International Nuclear Information System (INIS)

    Drexler, J.Z.; Paces, J.B.; Alpers, C.N.; Windham-Myers, L.; Neymark, L.A.; Bullen, T.D.; Taylor, H.E.

    2014-01-01

    Highlights: • Concentrations and isotopic values of Sr and U in peat were used to trace paleosalinity. • A three-end-member mixing model was constructed using values from water sources. • Paleosalinity of peat samples was determined relative to that of end members. • δ 87 Sr values were altered during and after the California Gold Rush period. • Oligohaline and freshwater marshes have long existed in the Sacramento-San Joaquin Delta. - Abstract: The purpose of this study was to determine the history of paleosalinity over the past 6000+ years in the Sacramento-San Joaquin Delta (the Delta), which is the innermost part of the San Francisco Estuary. We used a combination of Sr and U concentrations, δ 87 Sr values, and 234 U/ 238 U activity ratios (AR) in peat as proxies for tracking paleosalinity. Peat cores were collected in marshes on Browns Island, Franks Wetland, and Bacon Channel Island in the Delta. Cores were dated using 137 Cs, the onset of Pb and Hg contamination from hydraulic gold mining, and 14 C. A proof of concept study showed that the dominant emergent macrophyte and major component of peat in the Delta, Schoenoplectus spp., incorporates Sr and U and that the isotopic composition of these elements tracks the ambient water salinity across the Estuary. Concentrations and isotopic compositions of Sr and U in the three main water sources contributing to the Delta (seawater, Sacramento River water, and San Joaquin River water) were used to construct a three-end-member mixing model. Delta paleosalinity was determined by examining variations in the distribution of peat samples through time within the area delineated by the mixing model. The Delta has long been considered a tidal freshwater marsh region, but only peat samples from Franks Wetland and Bacon Channel Island have shown a consistently fresh signal (<0.5 ppt) through time. Therefore, the eastern Delta, which occurs upstream from Bacon Channel Island along the San Joaquin River and its

  6. Characterizing Drought Impacted Soils in the San Joaquin Valley of California Using Remote Sensing

    Science.gov (United States)

    Wahab, L. M.; Miller, D.; Roberts, D. A.

    2017-12-01

    California's San Joaquin Valley is an extremely agriculturally productive region of the country, and understanding the state of soils in this region is an important factor in maintaining this high productivity. In this study, we quantified changing soil cover during the drought and analyzed spatial changes in salinity, organic matter, and moisture using unique soil spectral characteristics. We used data from the Airborne Visible / Infrared Imaging Spectrometer (AVIRIS) from Hyperspectral Infrared Imager (HyspIRI) campaign flights in 2013 and 2014 over the San Joaquin Valley. A mixture model was applied to both images that identified non- photosynthetic vegetation, green vegetation, and soil cover fractions through image endmembers of each of these three classes. We optimized the spectral library used to identify these classes with Iterative Endmember Selection (IES), and the images were unmixed using Multiple Endmember Spectral Mixture Analysis (MESMA). Maps of soil electrical conductivity, organic matter, soil saturated moisture, and field moisture were generated for the San Joaquin Valley based on indices developed by Ben-Dor et al. [2002]. Representative polygons were chosen to quantify changes between years. Maps of spectrally distinct soils were also generated for 2013 and 2014, in order to determine the spatial distribution of these soil types as well as their temporal dynamics between years. We estimated that soil cover increased by 16% from 2013-2014. Six spectrally distinct soil types were identified for the region, and it was determined that the distribution of these soil types was not constant for most areas between 2013 and 2014. Changes in soil pH, electrical conductivity, and soil moisture were strongly tied in the region between 2013 and 2014.

  7. 75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2010-01-19

    ...EPA is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District portion of the California State Implementation Plan (SIP). These revisions were proposed in the Federal Register on June 16, 2009 and concern volatile organic compound (VOC) emissions from coating of metal parts, large appliances, metal furniture, motor vehicles, mobile equipment, cans, coils, organic solvent cleaning, and storage and disposal related to such operations. We are approving local rules that regulate these emission sources under the Clean Air Act as amended in 1990 (CAA or the Act).

  8. 77 FR 66429 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-11-05

    ...EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). These revisions concern volatile organic compounds (VOC), carbon monoxide (CO), oxides of nitrogen (NOX), oxides of sulfur (SOX), and particulate matter (PM) emissions from glass melting furnaces. We are approving a local rule that regulates these emission sources under the Clean Air Act (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

  9. 76 FR 16696 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-03-25

    ...EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). These revisions were proposed in the Federal Register on November 5, 2010 and concern oxides of nitrogen (NOX), carbon monoxide (CO), oxides of sulfur (SO2) and particulate matter emissions from boilers, steam generators and process heaters greater than 5.0 MMbtu/hour. We are approving a local rule that regulates these emission sources under the Clean Air Act as amended in 1990 (CAA or the Act).

  10. Thermal history of rocks in southern San Joaquin Valley, California: evidence from fission-track analysis

    Science.gov (United States)

    Naeser, N.D.; Naeser, C.W.; McCulloh, T.H.

    1990-01-01

    Fission-track analysis has been used to study the thermal and depositional history of the subsurface Tertiary sedimentary rocks on both sides of the active White Wolf reverse fault in the southern San Joaquin Valley. The distinctly different thermal histories of the rocks in the two structural blocks are clearly reflected in the apatite fission-track data, which suggest that rocks in the rapidly subsiding basin northwest of the fault have been near their present temperature for only about 1 m.y. compared with about 10 m.y. for rocks southeast of the fault. These estimates of heating time agree with previous estimates for these rocks. Zircon fission-track data indicate that the Tertiary sediments were derived from parent rocks of more than one age. However, from at least the Eocene to late Miocene or Pliocene, the major sediment source was rocks related to the youngest Sierra Nevada Mesozoic intrusive complexes, which are presently exposed east and south of the southern San Joaquin Valley. -from Authors

  11. Understanding Particulate Matter Dynamics in the San Joaquin Valley during DISCOVER-AQ, 2013

    Science.gov (United States)

    Prabhakar, G.; Zhang, X.; Kim, H.; Parworth, C.; Pusede, S. E.; Wooldridge, P. J.; Cohen, R. C.; Zhang, Q.; Cappa, C. D.

    2015-12-01

    Air quality in the California San Joaquin Valley (SJV) during winter continues to be the worst in the state, failing EPA's 24-hour standard for particulate matter. Despite our improved understanding of the sources of particulate matter (PM) in the valley, air-quality models are unable to predict PM concentrations accurately. We aim to characterize periods of high particulate matter concentrations in the San Joaquin Valley based on ground and airborne measurements of aerosols and gaseous pollutants, during the DISCOVER-AQ campaign, 2013. A highly instrumented aircraft flew across the SJV making three transects in a repeatable pattern, with vertical spirals over select locations. The aircraft measurements were complemented by ground measurements at these locations, with extensive chemically-speciated measurements at a ground "supersite" at Fresno. Hence, the campaign provided a comprehensive three-dimensional view of the particulate and gaseous pollutants around the valley. The vertical profiles over the different sites indicate significant variability in the concentrations and vertical distribution of PM around the valley, which are most likely driven by differences in the combined effects of emissions, chemistry and boundary layer dynamics at each site. The observations suggest that nighttime PM is dominated by surface emissions of PM from residential fuel combustion, while early morning PM is strongly influenced by mixing of low-level, above-surface, nitrate-rich layers formed from dark chemistry overnight to the surface.

  12. Sturgeon in the Sacramento–San Joaquin Watershed: New Insights to Support Conservation and Management

    Directory of Open Access Journals (Sweden)

    A. Peter Klimley

    2015-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss4art1The goal of a day-long symposium on March 3, 2015, Sturgeon in the Sacramento–San Joaquin Watershed: New Insights to Support Conservation and Management, was to present new information about the physiology, behavior, and ecology of the green (Acipenser medirostris and white sturgeon (Acipenser transmontanus to help guide enhanced management and conservation efforts within the Sacramento–San Joaquin watershed. This symposium identified current unknowns and highlighted new electronic tracking technologies and physiological techniques to address these knowledge gaps. A number of presentations, each reviewing ongoing research on the two species, was followed by a round-table discussion, in which each of the participants was asked to share recom-mendations for future research on sturgeon in the watershed. This article presents an in-depth review of the scientific information presented at the sympo-sium with a summary of recommendations for future research.

  13. Use of ground-water reservoirs for storage of surface water in the San Joaquin Valley, California

    Science.gov (United States)

    Davis, G.H.; Lofgren, B.E.; Mack, Seymour

    1964-01-01

    The San Joaquin Valley includes roughly the southern two-thirds of the Central Valley of California, extending 250 miles from Stockton on the north to Grapevine at the foot of the Tehachapi Mountains. The valley floor ranges in width from 25 miles near Bakersfield to about 55 miles near Visalia; it has a surface area of about 10,000 square miles. More than one-quarter of all the ground water pumped for irrigation in the United States is used in this highly productive valley. Withdrawal of ground water from storage by heavy pumping not only provides a needed irrigation water supply, but it also lowers the ground-water level and makes storage space available in which to conserve excess water during periods of heavy runoff. A storage capacity estimated to be 93 million acre-feet to a depth of 200 feet is available in this ground-water reservoir. This is about nine times the combined capacity of the existing and proposed surface-water reservoirs in the San Joaquin Valley under the California Water Plan. The landforms of the San Joaquin Valley include dissected uplands, low plains and fans, river flood plains and channels, and overflow lands and lake bottoms. Below the land surface, unconsolidated sediments derived from the surrounding mountain highlands extend downward for hundreds of feet. These unconsolidated deposits, consisting chiefly of alluvial deposits, but including some widespread lacustrine sediments, are the principal source of ground water in the valley. Ground water occurs under confined and unconfined conditions in the San Joaquin Valley. In much of the western, central, and southeastern parts of the valley, three distinct ground-water reservoirs are present. In downward succession these are 1) a body of unconfined and semiconfined fresh water in alluvial deposits of Recent, Pleistocene, and possibly later Pliocene age, overlying the Corcoran clay member of the Tulare formation; 2) a body of fresh water confined beneath the Corcoran clay member, which

  14. Quaternary geology of Alameda County, and parts of Contra Costa, Santa Clara, San Mateo, San Francisco, Stanislaus, and San Joaquin counties, California: a digital database

    Science.gov (United States)

    Helley, E.J.; Graymer, R.W.

    1997-01-01

    Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map. The Quaternary deposits in Alameda County comprise three distinct depositional environments. One, forming a transgressive sequence of alluvial fan and fan-delta facies, is mapped in the western one-third of the county. The second, forming only alluvial fan facies, is mapped in the Livermore Valley and San Joaquin Valley in the eastern part of the county. The third, forming a combination of Eolian dune and estuarine facies, is restricted to the Alameda Island area in the northwestern corner of the county.

  15. Subsidence due to Excessive Groundwater Withdrawal in the San Joaquin Valley, California

    Science.gov (United States)

    Corbett, F.; Harter, T.; Sneed, M.

    2011-12-01

    Francis Corbett1, Thomas Harter1 and Michelle Sneed2 1Department of Land Air and Water Resources, University of California, Davis. 2U.S. Geological Survey Western Remote Sensing and Visualization Center, Sacramento. Abstract: Groundwater development within the Central Valley of California began approximately a century ago. Water was needed to supplement limited surface water supplies for the burgeoning population and agricultural industries, especially within the arid but fertile San Joaquin Valley. Groundwater levels have recovered only partially during wet years from drought-induced lows creating long-term groundwater storage overdraft. Surface water deliveries from Federal and State sources led to a partial alleviation of these pressure head declines from the late 1960s. However, in recent decades, surface water deliveries have declined owing to increasing environmental pressures, whilst water demands have remained steady. Today, a large portion of the San Joaquin Valley population, and especially agriculture, rely upon groundwater. Groundwater levels are again rapidly declining except in wet years. There is significant concern that subsidence due to groundwater withdrawal, first observed at a large scale in the middle 20th century, will resume as groundwater resources continue to be depleted. Previous subsidence has led to problems such as infrastructure damage and flooding. To provide a support tool for groundwater management on a naval air station in the southern San Joaquin Valley (Tulare Lake Basin), a one-dimensional MODFLOW subsidence model covering the period 1925 to 2010 was developed incorporating extensive reconstruction of historical subsidence and water level data from various sources. The stratigraphy used for model input was interpreted from geophysical logs and well completion reports. Gaining good quality data proved problematic, and often values needed to be estimated. In part, this was due to the historical lack of awareness/understanding of

  16. Social Disparities in Drinking Water Quality in California's San Joaquin Valley

    Science.gov (United States)

    Ray, I.; Balazs, C.; Hubbard, A.; Morello-Frosch, R.

    2011-12-01

    Social Disparities in Drinking Water Quality in California's San Joaquin Valley Carolina Balazs, Rachel Morello-Frosch, Alan Hubbard and Isha Ray Little attention has been given to research on social disparities and environmental justice in access to safe drinking water in the USA. We examine the relationship between nitrate and arsenic concentrations in community water systems (CWS) and the ethnic and socioeconomic characteristics of their customers. We hypothesized that systems in the San Joaquin Valley that serve a higher proportion of minority (especially Latino) residents, and/or lower socioeconomic status (proxied by rates of home ownership) residents, have higher nitrate levels and higher arsenic levels. We used water quality monitoring datasets (1999-2001) to estimate nitrate as well as arsenic levels in CWS, and source location and Census block group data to estimate customer demographics. We found that percent Latino was associated with a .04 mg NO3/L increase in a CWS' estimated nitrate ion concentration (95% CI, -.08, .16) and rate of home ownership was associated with a .16 mg NO3/L decrease (95% CI, -.32, .002). We also found that each percent increase in home ownership rate was associated with a .30 ug As/L decrease in arsenic concentrations (pcompliance burdens in accordance with EPA standards fell most heavily on socio-economically disadvantaged communities. Selected References Cory DC, Rahman T. 2009. Environmental justice and enforcement of the safe drinking water act: The arizona arsenic experience. Ecological Economics 68: 1825-1837. Krieger N, Williams DR, Moss NE. 1997. Measuring social class in us public health research: Concepts, methodologies, and guidelines. Annual Review of Public Health 18(341-378). Moore E, Matalon E, Balazs C, Clary J, Firestone L, De Anda S, Guzman, M. 2011. The human costs of nitrate-contaminated drinking water in the San Joaquin Valley. Oakland, CA: Pacific Institute. Morello-Frosch R, Pastor M, Sadd J. 2001

  17. Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth; Jurgens, Bryant C.

    2010-01-01

    Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by the State of California and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The Northern San Joaquin study unit was the third study unit to be designed and sampled as part of the Priority Basin Project. Results of the study provide a spatially unbiased assessment of the quality of raw (untreated) groundwater, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 61 wells in parts of Alameda, Amador, Calaveras, Contra Costa, San Joaquin, and Stanislaus Counties; 51 of the wells were selected using a spatially distributed, randomized grid-based approach to provide statistical representation of the study area (grid wells), and 10 of the wells were sampled to increase spatial density and provide additional information for the evaluation of water chemistry in the study unit (understanding/flowpath wells). The primary aquifer systems (hereinafter, primary aquifers) assessed in this study are defined by the depth intervals of the wells in the California Department of Public Health database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. Two types of assessments were made: (1) status, assessment of the current quality of the groundwater resource; and (2) understanding, identification of the natural and human factors

  18. Data release for persistence of historical population structure in an endangered species despite near-complete biome conversion in California’s San Joaquin Desert

    Data.gov (United States)

    Department of the Interior — The recency of large-scale land conversion in California’s San Joaquin Desert raises the probability that the region’s numerous endemic species still retain genetic...

  19. The Sacramento-San Joaquin Delta Conflict: Strategic Insights for California's Policymakers

    Science.gov (United States)

    Moazezi, M. R.

    2013-12-01

    The Sacramento-San Joaquin Delta - a major water supply source in California and a unique habitat for many native and invasive species--is on the verge of collapse due to a prolonged conflict over how to manage the Delta. There is an urgent need to expedite the resolution of this conflict because the continuation of the status quo would leave irreversible environmental consequences for the entire state. In this paper a systematic technique is proposed for providing strategic insights into the Sacramento-San Joaquin Delta conflict. Game theory framework is chosen to systematically analyze behavioral characteristics of decision makers as well as their options in the conflict with respect to their preferences using a formal mathematical language. The Graph Model for Conflict Resolution (GMCR), a recent game-theoretic technique, is applied to model and analyze the Delta conflict in order to better understand the options, preferences, and behavioral characteristics of the major decision makers. GMCR II as a decision support system tool based on GMCR concept is used to facilitate the analysis of the problem through a range of non-cooperative game theoretic stability definitions. Furthermore, coalition analysis is conducted to analyze the potential for forming partial coalitions among decision makers, and to investigate how forming a coalition can influence the conflict resolution process. This contribution shows that involvement of the State of California is necessary for developing an environmental-friendly resolution for the Delta conflict. It also indicates that this resolution is only achievable through improving the fragile levee systems and constructing a new water export facility.

  20. Erratum dated 2014 June 25: Fate and Transport of Three Pharmaceuticals in the Sacramento-San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Minta M. Schaefer

    2013-06-01

    Full Text Available Pharmaceuticals and personal care products (PPCPs are found in surface waters worldwide. Wastewater treatment plant effluent is a major source of these contaminants. The Sacramento–San Joaquin Delta (Delta is a unique aquatic ecosystem, a source of drinking water for over 25 million Californians, and a primary source of water for Central Valley agriculture. The sharp decline of four pelagic fish species in the Delta in the last decade is just one of several indicators that the ecosystem is severely impaired. Several wastewater treatment plants (WWTPs discharge into the Delta, directly or through tributaries. The presence of PPCPs in the Delta has received very little attention relative to the immense effort underway to rehabilitate the ecosystem. This study determined concentrations of PPCPs in the Sacramento River in the vicinity of the Sacramento Regional Wastewater Treatment Plant using passive sampler monitoring. These data were used to estimate loads of three of the detected pharmaceuticals (carbamazepine, fluoxetine, and trimethoprim from nine other WWTPs that discharge to the Delta. The 2-D, finite element, Resource Management Associates (RMA Delta Model was then applied to determine the distribution that might result from these discharges. The model was run for the 2006, 2007, and 2009 water years. Results indicate that it is feasible that WWTP discharges could result in chronic presence of these pharmaceuticals at low ng L-1 levels at all 45 model output locations and, therefore, aquatic organisms within the Delta may be continually exposed to these contaminants.

  1. Executive Summary -- assessment of undiscovered oil and gas resources of the San Joaquin Basin Province of California, 2003: Chapter 1 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    Science.gov (United States)

    Gautier, Donald L.; Scheirer, Allegra Hosford; Tennyson, Marilyn E.; Peters, Kenneth E.; Magoon, Leslie B.; Lillis, Paul G.; Charpentier, Ronald R.; Cook, Troy A.; French, Christopher D.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2007-01-01

    In 2003, the U.S. Geological Survey (USGS) completed an assessment of the oil and gas resource potential of the San Joaquin Basin Province of California (fig. 1.1). The assessment is based on the geologic elements of each Total Petroleum System defined in the province, including hydrocarbon source rocks (source-rock type and maturation and hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined five total petroleum systems and ten assessment units within these systems. Undiscovered oil and gas resources were quantitatively estimated for the ten assessment units (table 1.1). In addition, the potential was estimated for further growth of reserves in existing oil fields of the San Joaquin Basin.

  2. Investigating Particle Transport and Fate in the Sacramento–San Joaquin Delta Using a Particle-Tracking Model

    Directory of Open Access Journals (Sweden)

    Wim J. Kimmerer

    2008-02-01

    Full Text Available Movements of pelagic organisms in the tidal freshwater regions of estuaries are sensitive to the movements of water. In the Sacramento-San Joaquin Delta—the tidal freshwater reach of the San Francisco Estuary—such movements are key to losses of fish and other organisms to entrainment in large water-export facilities. We used the Delta Simulation Model-2 hydrodynamic model and its particle tracking model to examine the principal determinants of entrainment losses to the export facilities and how movement of fish through the Delta may be influenced by flow. We modeled 936 scenarios for 74 different conditions of flow, diversions, tides, and removable barriers to address seven questions regarding hydrodynamics and entrainment risk in the Delta. Tide had relatively small effects on fate and residence time of particles. Release location and hydrology interacted to control particle fate and residence time. The ratio of flow into the export facilities to freshwater flow into the Delta (export:inflow or EI ratio was a useful predictor of entrainment probability if the model were allowed to run long enough to resolve particles’ ultimate fate. Agricultural diversions within the Delta increased total entrainment losses and altered local movement patterns. Removable barriers in channels of the southern Delta and gates in the Delta Cross Channel in the northern Delta had minor effects on particles released in the rivers above these channels. A simulation of losses of larval delta smelt showed substantial cumulative losses depending on both inflow and export flow. A simulation mimicking mark–recapture experiments on Chinook salmon smolts suggested that both inflow and export flow may be important factors determining survival of salmon in the upper estuary. To the extent that fish behave passively, this model is probably suitable for describing Delta-wide movement, but it is less suitable for smaller scales or alternative configurations of the Delta.

  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.

  4. 77 FR 24857 - Interim Final Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-04-26

    ...EPA is making an interim final determination to stay the imposition of offset sanctions and to defer the imposition of highway sanctions based on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP) published elsewhere in this Federal Register. The revisions concern SJVUAPCD Rule 4352, Solid Fuel Fired Boilers, Steam Generators and Process Heaters.

  5. 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

  6. Winters-Domengine Total Petroleum System—Northern Nonassociated Gas Assessment Unit of the San Joaquin Basin Province: Chapter 21 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    Science.gov (United States)

    Hosford Scheirer, Allegra; Magoon, Leslie B.

    2008-01-01

    The Northern Nonassociated Gas Assessment Unit (AU) of the Winters-Domengine Total Petroleum System of the San Joaquin Basin Province consists of all nonassociated gas accumulations in Cretaceous, Eocene, and Miocene sandstones located north of township 15 South in the San Joaquin Valley. The northern San Joaquin Valley forms a northwest-southeast trending asymmetrical trough. It is filled with an alternating sequence of Cretaceous-aged sands and shales deposited on Franciscan Complex, ophiolitic, and Sierran basement. Eocene-aged strata unconformably overlie the thick Cretaceous section, and in turn are overlain unconformably by nonmarine Pliocene-Miocene sediments. Nonassociated gas accumulations have been discovered in the sands of the Panoche, Moreno, Kreyenhagen, andDomengine Formations and in the nonmarine Zilch formation of Loken (1959) (hereafter referred to as Zilch formation). Most hydrocarbon accumulations occur in low-relief, northwest-southeast trending anticlines formed chiefly by differential compaction of sediment and by northeast southwest directed compression during the Paleogene (Bartow, 1991) and in stratigraphic traps formed by pinch out of submarine fan sands against slope shales. To date, 176 billion cubic feet (BCF) of nonassociated recoverable gas has been found in fields within the assessment unit (table 21.1). A small amount of biogenic gas forms near the surface of the AU. Map boundaries of the assessment unit are shown in figures 21.1 and 21.2; in plan view, this assessment unit is identical to the Northern Area Nonassociated Gas play 1007 considered by the U.S. Geological Survey (USGS) in its 1995 National Assessment (Beyer, 1996). The AU is bounded on the east by the mapped limits of Cretaceous sandstone reservoir rocks and on the west by the east flank of the Diablo Range. The southern limit of the AU is the southernmost occurrence of nonassociated thermogenic-gas accumulations. The northern limit of the AU corresponds to the

  7. Generation of hydrogen peroxide from San Joaquin Valley particles in a cell-free solution

    Directory of Open Access Journals (Sweden)

    H. Shen

    2011-01-01

    Full Text Available Epidemiological studies have shown a correlation between exposure to ambient particulate matter (PM and adverse health effects. One proposed mechanism of PM-mediated health effects is the generation of reactive oxygen species (ROS – e.g., superoxide (O2, hydrogen peroxide (HOOH, and hydroxyl radical (OH – followed by oxidative stress. There are very few quantitative, specific measures of individual ROS generated from PM, but this information would help to more quantitatively address the link between ROS and the health effects of PM. To address this gap, we quantified the generation of HOOH by PM collected at an urban (Fresno and rural (Westside site in the San Joaquin Valley (SJV of California during summer and winter from 2006 to 2009. HOOH was quantified by HPLC after extracting the PM in a cell-free, phosphate-buffered saline (PBS solution with or without 50 μM ascorbate (Asc. Our results show that the urban PM generally generates much more HOOH than the rural PM but that there is no apparent seasonal difference in HOOH generation. In nearly all of the samples the addition of a physiologically relevant concentration of Asc greatly enhances HOOH formation, but a few of the coarse PM samples were able to generate a considerable amount of HOOH in the absence of added Asc, indicating the presence of unknown reductants. Normalized by air volume, the fine PM (PM2.5 generally makes more HOOH than the corresponding coarse PM (PMcf, i.e., 2.5 to 10 μm, primarily because the mass concentration of PM2.5 is much higher than that of PMcf. However, normalized by PM mass, the coarse PM typically generates more HOOH than the fine PM. The amount of HOOH produced by SJV PM is reduced on average by (78 ± 15% when the transition metal chelator desferoxamine (DSF is added to the extraction solution, indicating that transition metals play a dominant role in HOOH

  8. Analysis of the Causes of a Decline in the San Joaquin Kit Fox Population on the Elk Hills, Naval Petroleum Reserve #1, California

    Science.gov (United States)

    EPA is announcing the availability of the final report, Analysis of the Causes of a Decline in the San Joaquin Kit Fox Population on the Elk Hills, Naval Petroleum Reserve #1, California. This report describes a causal assessment of the decline in the abundance of San Joaq...

  9. Striped bass (Morone saxatilis) monitoring techniques in the Sacramento--San Joaquin Estuary

    International Nuclear Information System (INIS)

    Stevens, D.E.

    1977-01-01

    Various methods have been used to monitor the striped bass population in the Sacramento--San Joaquin Estuary. Sampling in the spring with towed plankton nets has provided an adequate description of spawning time and area, but this sampling has not adequately measured egg standing crops and larva and post-larva mortality rates. Tow-net sampling effectively measures the abundance of young in midsummer. A midwater-trawl survey is satisfactory for measuring the abundance of young in the fall but not in the winter. Techniques have not been fully evaluated for monitoring one-year-old bass. Catch-per-unit-effort data from sportfishing party boats were useful for monitoring two-year-olds, until a change in angling regulations increased recruitment age. The Petersen method and indices developed from party-boat catches are the best methods for monitoring bass that are three years old and older. Long-term trends in catch can be monitored through postcard surveys and party-boat catches

  10. Log analysis in the shallow oil sands of the San Joaquin Valley, California

    International Nuclear Information System (INIS)

    Vohs, J.B.

    1976-01-01

    Many fields in the San Joaquin Valley of California produce oil from a depth of 2,500 ft or less. During the period of primary production in these fields, evaluation of potential pay intervals from logs was restricted to examination of ES logs and correlation. With the introduction of secondary and tertiary recovery techniques the need for more and better answers, more quickly available, became apparent. However, several log-analysis problems had to be resolved. Formation evaluation using well logs was complicated by the shaliness of the sand intervals, the low and variable salinity of the formation waters, and the presence of low-pressure-gas (depleted) zones in many of the shallow sands. Solutions to these problems have required more modern logging programs and interpretation techniques. Logs available for the evaluation of these sands are the dual induction-laterolog, the compensated formation density log, the compensated neutron log, and the microlaterolog or proximity log. With this suite of logs it is possible to determine the shale content, porosity, saturation in the flushed zone, and water saturation of the sand, and to locate the low-pressure-gas sands and depleted zones. In cases where freshwater and oil are interlayered, it is possible to tell which sands contain oil and which contain only water. Because a quick interpretation is required, wellsite techniques are called for. These will be described

  11. Aircraft Observations of Nitrous Oxide (N2O) in the San Joaquin Valley of California

    Science.gov (United States)

    Muto, S.; Herrera, S.; Pusede, S.

    2017-12-01

    Agriculture is the largest source of anthropogenic nitrous oxide (N2O) in the U.S. While it is generally known which processes produce N2O, there is considerable uncertainty in controls over N2O emissions. Factors that determine N2O fluxes, such as soil properties and manure management, are highly variable in space and time, and, as a result, it has proven difficult to upscale chamber-derived soil flux measurements to regional spatial scales. Aircraft observations provide a regional picture of the N2O spatial distribution, but, because N2O is very long-lived, it is challenging to attribute measured concentrations of N2O to distinct local sources, especially over areas with complex and integrated land use. This study takes advantage of a novel aircraft N2O dataset collected onboard the low-flying, slow-moving NASA C-23 Sherpa in the San Joaquin Valley (SJV) of California, a region with a variety of N2O sources, including dairies, feedlots, fertilized cropland, and industrial facilities. With these measurements, we link observed N2O enhancements to specific sources at sub-inventory spatial scales. We compare our results with area-weighted emission profiles obtained by integrating detailed emission inventory data, agricultural statistics, and GIS source mapping.

  12. Environmental and indoor study of Radon concentration in San Joaquin area, Queretaro, Mexico, first results

    International Nuclear Information System (INIS)

    Hinojo Alonso, N.A.; Kotsarenko, A.; Yutsis, V.; Hernandez Silva, G.; Perego, P.; Fazio, M.; Grimalsky, V.; Koshevaya, S.; Foglia, F.; Cortes Silva, A.; García Martínez, R.; Martínez Reyes, J.; Norini, G.; Groppelli, G.

    2013-01-01

    A highly contaminated zone with a maximum over 57,000 Bq/m 3 was discovered in a populated community “Agua de Venados” during the 2009–2011 soil Radon survey in San Joaquin, Queretaro State, Mexico. The indoor Radon monitoring accomplished in 2 different époques in a nearby 4 dwellings has shown an increased Radon hazard in 1 of the 4 buildings (about 300 Bq/m 3 ) during a rainy season and highly elevated indoor Radon levels (over 400 Bq/m 3 ) already in 3 buildings during a dry season. The averaged diurnal indoor Radon variations are in a correlation with the atmospheric pressure and the air humidity and are independent on the air temperature. The maximum indoor Radon hazard for dwellings is estimated for the morning interval 5–10 a.m. - Highlights: ► Emanative zone of 57,000 Bq/m 3 was found in area “Agua de Venados”. ► Indoor Radon level in a nearby dwellings elevates during a dry season. ► Maximum risk for residents was estimated during the daily interval 5–10 a.m

  13. Collaboration, Participation and Technology: The San Joaquin Valley Cumulative Health Impacts Project

    Directory of Open Access Journals (Sweden)

    Jonathan K. London

    2011-11-01

    Full Text Available Community-university partnerships have been shown to produce significant value for both sets of partners by providing reciprocal learning opportunities, (rebuilding bonds of trust, and creating unique venues to formulate and apply research that responds to community interests and informs collaborative solutions to community problems. For such partnerships to be mutually empowering, certain design characteristics are necessary. These include mutual respect for different modes and expressions of knowledge, capacity-building for all parties, and an environment that promotes honest and constructive dialogue about the inevitable tensions associated with the interplay of power/knowledge. This article explores an innovative case of community-university partnerships through participatory action research involving a coalition of environmental justice and health advocates, the San Joaquin Valley Cumulative Health Impacts Project, and researchers affiliated with the University of California, Davis. In particular, we examine how participatory GIS and community mapping can promote co-learning and interdependent science. Keywords Community-based participatory research, environmental justice, Public Participation Geographic Information System

  14. Quantifying anthropogenic contributions to century-scale groundwater salinity changes, San Joaquin Valley, California, USA

    Science.gov (United States)

    Hansen, Jeffrey; Jurgens, Bryant; Fram, Miranda S.

    2018-01-01

    Total dissolved solids (TDS) concentrations in groundwater tapped for beneficial uses (drinking water, irrigation, freshwater industrial) have increased on average by about 100 mg/L over the last 100 years in the San Joaquin Valley, California (SJV). During this period land use in the SJV changed from natural vegetation and dryland agriculture to dominantly irrigated agriculture with growing urban areas. Century-scale salinity trends were evaluated by comparing TDS concentrations and major ion compositions of groundwater from wells sampled in 1910 (Historic) to data from wells sampled in 1993-2015 (Modern). TDS concentrations in subregions of the SJV, the southern (SSJV), western (WSJV), northeastern (NESJV), and southeastern (SESJV) were calculated using a cell-declustering method. TDS concentrations increased in all regions, with the greatest increases found in the SSJV and SESJV. Evaluation of the Modern data from the NESJV and SESJV found higher TDS concentrations in recently recharged (post-1950) groundwater from shallow (soil amendments combined. Bicarbonate showed the greatest increase among major ions, resulting from enhanced silicate weathering due to recharge of irrigation water enriched in CO2 during the growing season. The results of this study demonstrate that large anthropogenic changes to the hydrologic regime, like massive development of irrigated agriculture in semi-arid areas like the SJV, can cause large changes in groundwater quality on a regional scale.

  15. 1995 Integrated Monitoring Study: Fog measurements in the Southern San Joaquin Valley - preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Collett, J. Jr.; Bator, A.; Sherman, D.E. [Colorado State Univ., Fort Collins, CO (United States)] [and others

    1996-12-31

    Fogs were sampled at three ground-based stations in the southern portion of California`s San Joaquin Valley as part of the winter component of the 1995 Integrated Monitoring Study (IMS95). The three sampling sites included two urban locations (Bakersfield and Fresno) and one rural location (near the Kern Wildlife Refuge). Both bulk and drop size-fractionated samples were collected at each site. Several fog events were sampled, with three periods of extensive fog coverage that included all three sampling sites. Results of preliminary data analysis are presented. Fog collected at the sites was generally quite basic. Most bulk fog samples had pH values above 6 reflecting strong inputs from ammonia. Occasional strong sulfur plumes at Bakersfield, however, tended to lower the fog pH. Aside from these periods, nitrate was generally present at much higher concentrations in the fog than sulfate. Decreases in fogwater loadings of major species over the course of one extended fog episode at Fresno suggest significant deposition was occurring to the surface, consistent with observations of substantial droplet fluxes to exposed surfaces during that period. 16 refs., 7 figs., 1 tab.

  16. 1995 Integrated Monitoring Study: Fog measurements in the Northern San Joaquin Valley - preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Collett, J. Jr.; Bator, A.; Sherman, D.E. [Colorado State Univ., Fort Collins, CO (United States)] [and others

    1996-12-31

    Vertical gradients in fog chemistry and physics were measured from a 430 m television broadcast tower in the northern San Joaquin Valley near Walnut Grove, California. Fog was collected on the ground and at two elevations on the tower using Caltech Active Strand Cloudwater Collectors Version 2 (CASCC2). Work was conducted as part of the 1995 Integrated Monitoring Study (IMS95). Results will be used to evaluate the need to make measurements aloft in future regional studies of fog processing of atmospheric particles and for testing whether vertically resolved fog models provide realistic simulations of fog physics and chemistry above the ground. Two fog/low cloud events were sampled during the tower study. Preliminary results show concentrations of major species in the fogwater typically decreasing with altitude, while liquid water contents increase. Fogwater loadings of major species, the total amount of a species in the aqueous phase per unit air volume, were observed to increase with altitude. Major species concentrations were typically quite stable at a given elevation, while significant decreases were observed over time in liquid water content. Fogwater concentrations of soluble hydroperoxides were highest near the surface and increased with time after sunrise and were observed to coexist in the high pH fog with S(IV). Time lapse video footage of the top of the fog/cloud layer revealed a very dynamic interface, suggesting entrainment of material from the clear air into the fog/cloud may be significant. 12 refs., 7 figs.

  17. Agricultural pesticide use and adverse birth outcomes in the San Joaquin Valley of California.

    Science.gov (United States)

    Larsen, Ashley E; Gaines, Steven D; Deschênes, Olivier

    2017-08-29

    Virtually all agricultural communities worldwide are exposed to agricultural pesticides. Yet, the health consequences of such exposure are poorly understood, and the scientific literature remains ambiguous. Using individual birth and demographic characteristics for over 500 000 birth observations between 1997-2011 in the agriculturally dominated San Joaquin Valley, California, we statistically investigate if residential agricultural pesticide exposure during gestation, by trimester, and by toxicity influences birth weight, gestational length, or birth abnormalities. Overall, our analysis indicates that agricultural pesticide exposure increases adverse birth outcomes by 5-9%, but only among the population exposed to very high quantities of pesticides (e.g., top 5th percentile, i.e., ~4200 kg applied over gestation). Thus, policies and interventions targeting the extreme right tail of the pesticide distribution near human habitation could largely eliminate the adverse birth outcomes associated with agricultural pesticide exposure documented in this study.The health consequences of exposure to pesticides are uncertain and subject to much debate. Here, the effect of exposure during pregnancy is investigated in an agriculturally dominated residential area, showing that an increase in adverse birth outcomes is observed with very high levels of pesticide exposure.

  18. Size, Composition, and Sources of Health Relevant Particulate Matter in the San Joaquin Valley

    Science.gov (United States)

    Ham, Walter Allan

    Particulate Matter (PM) is an environment contaminant that has been associated with adverse health effects in epidemiological and toxicological studies. Atmospheric PM is made up of a diverse array of chemical species that are emitted from multiple sources across a range of aerodynamic diameters spanning several orders of magnitude. The focus of the present work was the characterization of ambient PM with aerodynamic diameters below 1.8 mum (PM1.8) in 6 size sub-fractions including PM0.1. Chemical species measured included organic carbon, elemental carbon, water soluble ions, trace metals, and organic molecular markers in urban and rural environments in the San Joaquin Valley. These measurements were used to determine differences in relative diurnal size distributions during a severe winter stagnation event, seasonal changes in PM size and composition, and the source origin of carbonaceous PM. This size-resolved information was used to calculate lung deposition patterns of health relevant PM species to evaluate seasonal differences in PM dose. By accurately calculating PM dose, researchers are able to more directly link ambient PM characterization data with biological endpoints. All of these results are used to support ongoing toxicological health effects studies. These types of analyses are important as this type of information may assist regulators with developing control strategies to reduce health effects caused by particulate air pollution.

  19. An Overview of Multi-Dimensional Models of the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Michael L. MacWilliams

    2016-12-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art2Over the past 15 years, the development and application of multi-dimensional hydrodynamic models in San Francisco Bay and the Sacramento–San Joaquin Delta has transformed our ability to analyze and understand the underlying physics of the system. Initial applications of three-dimensional models focused primarily on salt intrusion, and provided a valuable resource for investigating how sea level rise and levee failures in the Delta could influence water quality in the Delta under future conditions. However, multi-dimensional models have also provided significant insights into some of the fundamental biological relationships that have shaped our thinking about the system by exploring the relationship among X2, flow, fish abundance, and the low salinity zone. Through the coupling of multi-dimensional models with wind wave and sediment transport models, it has been possible to move beyond salinity to understand how large-scale changes to the system are likely to affect sediment dynamics, and to assess the potential effects on species that rely on turbidity for habitat. Lastly, the coupling of multi-dimensional hydrodynamic models with particle tracking models has led to advances in our thinking about residence time, the retention of food organisms in the estuary, the effect of south Delta exports on larval entrainment, and the pathways and behaviors of salmonids that travel through the Delta. This paper provides an overview of these recent advances and how they have increased our understanding of the distribution and movement of fish and food organisms. The applications presented serve as a guide to the current state of the science of Delta modeling and provide examples of how we can use multi-dimensional models to predict how future Delta conditions will affect both fish and water supply.

  20. Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California

    Science.gov (United States)

    Miller, R.L.; Fujii, R.

    2010-01-01

    Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates. ?? Springer Science+Business Media B.V. 2009.

  1. Groundwater quality in the Western San Joaquin Valley study unit, 2010: California GAMA Priority Basin Project

    Science.gov (United States)

    Fram, Miranda S.

    2017-06-09

    Water quality in groundwater resources used for public drinking-water supply in the Western San Joaquin Valley (WSJV) was investigated by the USGS in cooperation with the California State Water Resources Control Board (SWRCB) as part of its Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The WSJV includes two study areas: the Delta–Mendota and Westside subbasins of the San Joaquin Valley groundwater basin. Study objectives for the WSJV study unit included two assessment types: (1) a status assessment yielding quantitative estimates of the current (2010) status of groundwater quality in the groundwater resources used for public drinking water, and (2) an evaluation of natural and anthropogenic factors that could be affecting the groundwater quality. The assessments characterized the quality of untreated groundwater, not the quality of treated drinking water delivered to consumers by water distributors.The status assessment was based on data collected from 43 wells sampled by the U.S. Geological Survey for the GAMA Priority Basin Project (USGS-GAMA) in 2010 and data compiled in the SWRCB Division of Drinking Water (SWRCB-DDW) database for 74 additional public-supply wells sampled for regulatory compliance purposes between 2007 and 2010. To provide context, concentrations of constituents measured in groundwater were compared to U.S. Environmental Protection Agency (EPA) and SWRCB-DDW regulatory and non-regulatory benchmarks for drinking-water quality. The status assessment used a spatially weighted, grid-based method to estimate the proportion of the groundwater resources used for public drinking water that has concentrations for particular constituents or class of constituents approaching or above benchmark concentrations. This method provides statistically unbiased results at the study-area scale within the WSJV study unit, and permits comparison of the two study areas to other areas assessed by the GAMA Priority Basin Project

  2. SRTM Perspective View with Landsat Overlay: Mt. Pinos and San Joaquin Valley, California

    Science.gov (United States)

    2000-01-01

    Ask any astronomer where the best stargazing site in Southern California is, and chances are they'll say Mt. Pinos. In this perspective view generated from SRTM elevation data the snow-capped peak is seen rising to an elevation of 2,692 meters (8,831 feet), in stark contrast to the flat agricultural fields of the San Joaquin valley seen in the foreground. Below the summit, but still well away from city lights, the Mt. Pinos parking lot at 2,468 meters (8,100 feet) is a popular viewing area for both amateur and professional astronomers and astro-photographers. For visualization purposes, topographic heights displayed in this image are exaggerated two times.The elevation data used in this image was acquired by 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 Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.Distance to Horizon: 176 kilometers (109 miles) Location: 34.83 deg. North lat., 119.25 deg. West lon. View: Toward the Southwest Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

  3. Processes Affecting Agricultural Drainwater Quality and Organic Carbon Loads in California's Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Steven J. Deverel

    2007-05-01

    Full Text Available From 2000 to 2003 we quantified drain flow, drain-and ground-water chemistry and hydrogeologic conditions on Twitchell Island in the Sacramento-San Joaquin Delta. The primary objective was to quantify processes affecting organic carbon concentrations and loads in agricultural drainage water. We collected physical and chemical data in southern and northern areas: TN and TS, respectively. Corn grew in both areas during the spring and summer. The peat soils in the TN area are more decomposed than those in the TS area. Results elucidate processes affecting drain flow and concentrations under varying hydrologic conditions. During May through November, groundwater flows from the permanently saturated zone to drainage ditches, and the resulting average drainage-water quality and dissolved organic carbon (DOC concentration was similar to the groundwater; the median DOC loads in the TN and TS study areas ranged from 9 to 27 g C/ha-day. The major ion chemistry and stable isotope data confirmed that groundwater was the primary source of drainflow. In contrast, during December through April the drainwater is supplied from the shallow, variably saturated soil-zone. The DOC concentrations, major-ion chemistry, and stable isotope data indicate that the shallow-zone water is partially evaporated and oxidized. Higher flows and DOC concentrations during these months result in higher median DOC loads, which ranged from 84 to 280 g C/ha-day. During December through April, increasing groundwater levels in the shallow peat layers and mobilization of organic carbon result in high drain flow and increased trihalomethane precursor concentrations and loads. On a per mass DOC basis, drain water collected during high flow periods is less likely to form THMs than during low flow periods. However, the high flows and subsequent high concentrations contribute to substantially higher trihalomethane precursor and DOC loads.

  4. Data related uncertainty in near-surface vulnerability assessments for agrochemicals in the San Joaquin Valley.

    Science.gov (United States)

    Loague, Keith; Blanke, James S; Mills, Melissa B; Diaz-Diaz, Ricardo; Corwin, Dennis L

    2012-01-01

    Precious groundwater resources across the United States have been contaminated due to decades-long nonpoint-source applications of agricultural chemicals. Assessing the impact of past, ongoing, and future chemical applications for large-scale agriculture operations is timely for designing best-management practices to prevent subsurface pollution. Presented here are the results from a series of regional-scale vulnerability assessments for the San Joaquin Valley (SJV). Two relatively simple indices, the retardation and attenuation factors, are used to estimate near-surface vulnerabilities based on the chemical properties of 32 pesticides and the variability of both soil characteristics and recharge rates across the SJV. The uncertainties inherit to these assessments, derived from the uncertainties within the chemical and soil data bases, are estimated using first-order analyses. The results are used to screen and rank the chemicals based on mobility and leaching potential, without and with consideration of data-related uncertainties. Chemicals of historic high visibility in the SJV (e.g., atrazine, DBCP [dibromochloropropane], ethylene dibromide, and simazine) are ranked in the top half of those considered. Vulnerability maps generated for atrazine and DBCP, featured for their legacy status in the study area, clearly illustrate variations within and across the assessments. For example, the leaching potential is greater for DBCP than for atrazine, the leaching potential for DBCP is greater for the spatially variable recharge values than for the average recharge rate, and the leaching potentials for both DBCP and atrazine are greater for the annual recharge estimates than for the monthly recharge estimates. The data-related uncertainties identified in this study can be significant, targeting opportunities for improving future vulnerability assessments. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America

  5. Land subsidence in the San Joaquin Valley, California, USA, 2007-14

    Science.gov (United States)

    Sneed, Michelle; Brandt, Justin

    2015-01-01

    Rapid land subsidence was recently measured using multiple methods in two areas of the San Joaquin Valley (SJV): between Merced and Fresno (El Nido), and between Fresno and Bakersfield (Pixley). Recent land-use changes and diminished surface-water availability have led to increased groundwater pumping, groundwater-level declines, and land subsidence. Differential land subsidence has reduced the flow capacity of water-conveyance systems in these areas, exacerbating flood hazards and affecting the delivery of irrigation water. Vertical land-surface changes during 2007–2014 were determined by using Interferometric Synthetic Aperture Radar (InSAR), Continuous Global Positioning System (CGPS), and extensometer data. Results of the InSAR analysis indicate that about 7600 km2 subsided 50–540 mm during 2008–2010; CGPS and extensometer data indicate that these rates continued or accelerated through December 2014. The maximum InSAR-measured rate of 270 mm yr−1 occurred in the El Nido area, and is among the largest rates ever measured in the SJV. In the Pixley area, the maximum InSAR-measured rate during 2008–2010 was 90 mm yr−1. Groundwater was an important part of the water supply in both areas, and pumping increased when land use changed or when surface water was less available. This increased pumping caused groundwater-level declines to near or below historical lows during the drought periods 2007–2009 and 2012–present. Long-term groundwater-level and land-subsidence monitoring in the SJV is critical for understanding the interconnection of land use, groundwater levels, and subsidence, and evaluating management strategies that help mitigate subsidence hazards to infrastructure while optimizing water supplies.

  6. Air Pollution, Neighbourhood Socioeconomic Factors, and Neural Tube Defects in the San Joaquin Valley of California.

    Science.gov (United States)

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

    2015-11-01

    Environmental pollutants and neighbourhood socioeconomic factors have been associated with neural tube defects, but the potential impact of interaction between ambient air pollution and neighbourhood socioeconomic factors on the risks of neural tube defects is not well understood. We used data from the California Center of the National Birth Defects Study and the Children's Health and Air Pollution Study to investigate whether associations between air pollutant exposure in early gestation and neural tube defects were modified by neighbourhood socioeconomic factors in the San Joaquin Valley of California, 1997-2006. There were 5 pollutant exposures, 3 outcomes, and 9 neighbourhood socioeconomic factors included for a total of 135 investigated associations. Estimates were adjusted for maternal race-ethnicity, education, and multivitamin use. We present below odds ratios (ORs) that exclude 1 and a chi-square test of homogeneity P-value of <0.05. We observed increased odds of spina bifida comparing the highest to lowest quartile of particulate matter <10 μm (PM10 ) among those living in a neighbourhood with: (i) median household income of less than $30 000 per year [OR 5.1, 95% confidence interval (CI) 1.7, 15.3]; (ii) more than 20% living below the federal poverty level (OR 2.6, 95% CI 1.1, 6.0); and (iii) more than 30% with less than or equal to a high school education (OR 3.2, 95% CI 1.4, 7.4). The ORs were not statistically significant among those higher socioeconomic status (SES) neighbourhoods. Our results demonstrate effect modification by neighbourhood socioeconomic factors in the association of particulate matter and neural tube defects in California. © 2015 John Wiley & Sons Ltd.

  7. Historic, Recent, and Future Subsidence, Sacramento-San Joaquin Delta, California, USA

    Directory of Open Access Journals (Sweden)

    Steven J Deverel

    2010-08-01

    Full Text Available To estimate and understand recent subsidence, we collected elevation and soils data on Bacon and Sherman islands in 2006 at locations of previous elevation measurements. Measured subsidence rates on Sherman Island from 1988 to 2006 averaged 1.23 cm/year (0.5 in/yr and ranged from 0.7 to 1.7 cm/year (0.3 to 0.7 in/year. Subsidence rates on Bacon Island from 1978 to 2006 averaged 2.2 cm/year (0.9 in/yr and ranged from 1.5 to 3.7 cm/year (0.6 to 1.5 in/yr. Changing land-management practices and decreasing soil organic matter content have resulted in decreasing subsidence rates. On Sherman Island, rates from 1988 to 2006 were about 35% of 1910 to 1988 rates. For Bacon Island, rates from 1978 to 2006 were about 40% less than the 1926-1958 rates. To help understand causes and estimate future subsidence, we developed a subsidence model, SUBCALC, that simulates oxidation and carbon losses, consolidation, wind erosion, and burning and changing soil organic matter content. SUBCALC results agreed well with measured land-surface elevation changes. We predicted elevation decreases from 2007 to 2050 will range from a few centimeters to over 1.3 m (4.3 ft. The largest elevation declines will occur in the central Sacramento-San Joaquin Delta. From 2007 to 2050, the most probable estimated increase in volume below sea level is 349,956,000 million cubic meters (281,300 acre-feet. Consequences of this continuing subsidence include increased drainage loads of water quality constituents of concern, seepage onto islands, and decreased arability.

  8. Water savings from reduced alfalfa cropping in California's Upper San Joaquin Valley

    Science.gov (United States)

    Singh, K. K.; Gray, J.

    2017-12-01

    Water and food and forage security are inextricably linked. In fact, 90% of global freshwater is consumed for food production. Food demand increases as populations grow and diets change, making water increasingly scarce. This tension is particularly acute, contentious, and popularly appreciated in California's Central Valley, which is one of the most important non-grain cropping areas in the United States. While the water-intensive production of tree nuts like almonds and pistachios has received the most popular attention, it is California's nation-leading alfalfa production that consumes the most water. Alfalfa, the "Queen of Forages" is the preferred feedstock for California's prodigious dairy industry. It is grown year-round, and single fields can be harvested more than four times a year; a practice which can require in excess of 1.5 m of irrigation water. Given the water scarcity in the region, the production of alfalfa is under increasing scrutiny with respect to long-term sustainability. However, the potential water savings associated with alternative crops, and various levels of alfalfa replacement have not been quantified. Here, we address that knowledge gap by simulating the ecohydrology of the Upper San Joaquin's cropping system under various scenarios of alfalfa crop replacement with crops of comparable economic value. Specifically, we use the SWAT model to evaluate the water savings that would be realized at 33%, 66%, and 100% alfalfa replacement with economically comparable, but more water efficient crops such as tomatoes. Our results provide an important quantification of the potential water savings under alternative cropping systems that, importantly, also addresses the economic concerns of farmers. Results like these provide critical guidance to farmers and land/water decision makers as they plan for a more sustainable and productive agricultural future.

  9. Facilitating Adaptive Management in California’s Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    John A. Wiens

    2017-07-01

    Full Text Available https://doi.org/10.15447/sfews.2017v15iss2art3Uncertainties in understanding ecosystems increase the risk that management will fail to achieve desired results. Adaptive management is a structured, iterative application of science-based knowledge to reduce uncertainties and build flexibility into decision-making. However, adaptive management is more easily planned than implemented, and it is only beginning to be applied in the California’s Sacramento–San Joaquin Delta. We draw from two assessments of adaptive management in the Delta and examples of its use elsewhere to suggest how the process can be facilitated. Although a highly structured adaptive-management process may not always be needed, several elements are essential. Adaptive management should begin by clearly identifying the problem, goals, and objectives; recognizing uncertainties; identifying decision points and alternative approaches; recognizing when adjustments are needed and having the flexibility to make them; and considering societal and political constraints. Model complexity should be matched to that of the system and management needs; experiments can help unravel causal relationships. Monitoring, analyses, and syntheses require comprehensive data-management systems. More frequent and organized communications among scientists, managers, stakeholders, and decision-makers are necessary. We propose the establishment of an “Adaptive Management Team” to coordinate efforts across the management spectrum of the Delta and to provide guidance and link individual projects to shared approaches and experiences. Reliable long-term support will be needed to assess results of management actions, adjust approaches where improvement is likely, and strive toward the legislated goals of enhancing the Delta ecosystem while also providing reliable water supplies to much of California, and doing both these things in a manner that protects values of the Delta as a place where people live and

  10. Levee Vertical Land Motion Changes in the Sacramento-San Joaquin Delta

    Science.gov (United States)

    Telling, J. W.; Brooks, B. A.; Glennie, C. L.; Ericksen, T. L.; Knowles, N.

    2017-12-01

    The Sacramento-San Joaquin Delta is home to numerous islands that provide economically and agriculturally important land. However, the island interiors are sinking and most sit below sea level, making the levee roads that surround the islands vital for their continued health and productivity. Airborne LiDAR (Light Detection and Ranging) data over the islands was collected in 2007 by the California Department of Water Resources and mobile LiDAR data was collected along the levee roads on Bacon, Bouldin, Jersey, and Brannan-Andrus Islands in 2015 and 2016 by the USGS. These datasets provide high resolution topographic models with 8 year separation that can be used to examine topographic change along the levees. A cross-section of each dataset was output along the approximate centerline of the levee road, so that profiles of the 2007 and 2015/2016 LiDAR observations could be compared. Regions of levee road subsidence and of levee road construction and reinforcement on the order of 0-3 centimeters per year were evident in locations around the islands. There is a high degree of spatial variability of these rates even for individual islands. These results were compared to the levee road maps published by the CA Delta Stewardship Council and it was found that the regions of reinforcement and subsidence did not always align between the published maps and the LiDAR data. Additionally, the levee road heights and rates of change, in regions of road subsidence, were compared to sea level rise projections to evaluate the risk that rising sea level may pose to the islands in the future.

  11. Anthropogenic Methane Emissions in California's San Joaquin Valley: Characterizing Large Point Source Emitters

    Science.gov (United States)

    Hopkins, F. M.; Duren, R. M.; Miller, C. E.; Aubrey, A. D.; Falk, M.; Holland, L.; Hook, S. J.; Hulley, G. C.; Johnson, W. R.; Kuai, L.; Kuwayama, T.; Lin, J. C.; Thorpe, A. K.; Worden, J. R.; Lauvaux, T.; Jeong, S.; Fischer, M. L.

    2015-12-01

    Methane is an important atmospheric pollutant that contributes to global warming and tropospheric ozone production. Methane mitigation could reduce near term climate change and improve air quality, but is hindered by a lack of knowledge of anthropogenic methane sources. Recent work has shown that methane emissions are not evenly distributed in space, or across emission sources, suggesting that a large fraction of anthropogenic methane comes from a few "super-emitters." We studied the distribution of super-emitters in California's southern San Joaquin Valley, where elevated levels of atmospheric CH4 have also been observed from space. Here, we define super-emitters as methane plumes that could be reliably detected (i.e., plume observed more than once in the same location) under varying wind conditions by airborne thermal infrared remote sensing. The detection limit for this technique was determined to be 4.5 kg CH4 h-1 by a controlled release experiment, corresponding to column methane enhancement at the point of emissions greater than 20% above local background levels. We surveyed a major oil production field, and an area with a high concentration of large dairies using a variety of airborne and ground-based measurements. Repeated airborne surveys (n=4) with the Hyperspectral Thermal Emission Spectrometer revealed 28 persistent methane plumes emanating from oil field infrastructure, including tanks, wells, and processing facilities. The likelihood that a given source type was a super-emitter varied from roughly 1/3 for processing facilities to 1/3000 for oil wells. 11 persistent plumes were detected in the dairy area, and all were associated with wet manure management. The majority (11/14) of manure lagoons in the study area were super-emitters. Comparing to a California methane emissions inventory for the surveyed areas, we estimate that super-emitters comprise a minimum of 9% of inventoried dairy emissions, and 13% of inventoried oil emissions in this region.

  12. Economic Costs and Adaptations for Alternative Regulations of California's Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Stacy K. Tanaka

    2011-07-01

    Full Text Available Stacy K. Tanaka, Christina R. Connell–Buck, Kaveh Madani, Josue Medellín-Azuara, Jay R. Lund, and Ellen Hanakdoi: http://dx.doi.org/10.15447/sfews.2014v9iss2art4Water exports from California’s Sacramento–San Joaquin Delta are an environmental concern because they reduce net outflows of fresh water from the Delta, and can entrain fish and disrupt flows within the Delta. If exports were no longer pumped from within the Delta, the regulatory issue becomes one of maintaining appropriate flows into and out of the Delta. This paper presents the results of two sets of hydro-economic optimization modeling runs, which were developed to represent a range of modified Delta operations and their economic and operational effects on California’s water supply system. The first set of runs represents decreasing export capacity from the Delta. The second set increases minimum net Delta outflow (MNDO requirements. The hydro-economic model seeks the least–cost statewide water management scheme for water supply, including a wide range of resources and water management options. Results show that reducing exports or increasing MNDO requirements increase annual average statewide water scarcity, scarcity costs, and operating costs (from greater use of desalination, wastewater recycling, water treatment, and pumping. Effects of reduced exports are especially concentrated in agricultural communities in the southern Central Valley because of their loss of access to overall water supply exports and their ability to transfer remaining water to southern California. Increased outflow requirements increase water scarcity and associated costs throughout California. For an equivalent amount of average Delta outflows, statewide costs increase more rapidly when exports alone are reduced than when minimum outflow requirements are increased and effects are more widely distributed statewide.

  13. Social disparities in nitrate-contaminated drinking water in California's San Joaquin Valley.

    Science.gov (United States)

    Balazs, Carolina; Morello-Frosch, Rachel; Hubbard, Alan; Ray, Isha

    2011-09-01

    Research on drinking water in the United States has rarely examined disproportionate exposures to contaminants faced by low-income and minority communities. This study analyzes the relationship between nitrate concentrations in community water systems (CWSs) and the racial/ethnic and socioeconomic characteristics of customers. We hypothesized that CWSs in California's San Joaquin Valley that serve a higher proportion of minority or residents of lower socioeconomic status have higher nitrate levels and that these disparities are greater among smaller drinking water systems. We used water quality monitoring data sets (1999-2001) to estimate nitrate levels in CWSs, and source location and census block group data to estimate customer demographics. Our linear regression model included 327 CWSs and reported robust standard errors clustered at the CWS level. Our adjusted model controlled for demographics and water system characteristics and stratified by CWS size. Percent Latino was associated with a 0.04-mg nitrate-ion (NO3)/L increase in a CWS's estimated NO3 concentration [95% confidence interval (CI), -0.08 to 0.16], and rate of home ownership was associated with a 0.16-mg NO3/L decrease (95% CI, -0.32 to 0.002). Among smaller systems, the percentage of Latinos and of homeownership was associated with an estimated increase of 0.44 mg NO3/L (95% CI, 0.03-0.84) and a decrease of 0.15 mg NO3/L (95% CI, -0.64 to 0.33), respectively. Our findings suggest that in smaller water systems, CWSs serving larger percentages of Latinos and renters receive drinking water with higher nitrate levels. This suggests an environmental inequity in drinking water quality.

  14. Social Disparities in Nitrate-Contaminated Drinking Water in California’s San Joaquin Valley

    Science.gov (United States)

    Morello-Frosch, Rachel; Hubbard, Alan; Ray, Isha

    2011-01-01

    Background: Research on drinking water in the United States has rarely examined disproportionate exposures to contaminants faced by low-income and minority communities. This study analyzes the relationship between nitrate concentrations in community water systems (CWSs) and the racial/ethnic and socioeconomic characteristics of customers. Objectives: We hypothesized that CWSs in California’s San Joaquin Valley that serve a higher proportion of minority or residents of lower socioeconomic status have higher nitrate levels and that these disparities are greater among smaller drinking water systems. Methods: We used water quality monitoring data sets (1999–2001) to estimate nitrate levels in CWSs, and source location and census block group data to estimate customer demographics. Our linear regression model included 327 CWSs and reported robust standard errors clustered at the CWS level. Our adjusted model controlled for demographics and water system characteristics and stratified by CWS size. Results: Percent Latino was associated with a 0.04-mg nitrate-ion (NO3)/L increase in a CWS’s estimated NO3 concentration [95% confidence interval (CI), –0.08 to 0.16], and rate of home ownership was associated with a 0.16-mg NO3/L decrease (95% CI, –0.32 to 0.002). Among smaller systems, the percentage of Latinos and of homeownership was associated with an estimated increase of 0.44 mg NO3/L (95% CI, 0.03–0.84) and a decrease of 0.15 mg NO3/L (95% CI, –0.64 to 0.33), respectively. Conclusions: Our findings suggest that in smaller water systems, CWSs serving larger percentages of Latinos and renters receive drinking water with higher nitrate levels. This suggests an environmental inequity in drinking water quality. PMID:21642046

  15. Internal acid buffering in San Joaquin Valley fog drops and its influence on aerosol processing

    Science.gov (United States)

    Collett, Jeffrey L.; Hoag, Katherine J.; Rao, Xin; Pandis, Spyros N.

    Although several chemical pathways exist for S(IV) oxidation in fogs and clouds, many are self-limiting: as sulfuric acid is produced and the drop pH declines, the rates of these pathways also decline. Some of the acid that is produced can be buffered by uptake of gaseous ammonia. Additional internal buffering can result from protonation of weak and strong bases present in solution. Acid titrations of high pH fog samples (median pH=6.49) collected in California's San Joaquin Valley reveal the presence of considerable internal acid buffering. In samples collected at a rural location, the observed internal buffering could be nearly accounted for based on concentrations of ammonia and bicarbonate present in solution. In samples collected in the cities of Fresno and Bakersfield, however, significant additional, unexplained buffering was present over a pH range extending from approximately four to seven. The additional buffering was found to be associated with dissolved compounds in the fogwater. It could not be accounted for by measured concentrations of low molecular weight ( C1- C3) carboxylic acids, S(IV), phosphate, or nitrophenols. The amount of unexplained buffering in individual fog samples was found to correlate strongly with the sum of sample acetate and formate concentrations, suggesting that unmeasured organic species may be important contributors. Simulation of a Bakersfield fog episode with and without the additional, unexplained buffering revealed a significant impact on the fog chemistry. When the additional buffering was included, the simulated fog pH remained 0.3-0.7 pH units higher and the amount of sulfate present after the fog evaporated was increased by 50%. Including the additional buffering in the model simulation did not affect fogwater nitrate concentrations and was found to slightly decrease ammonium concentrations. The magnitude of the buffering effect on aqueous sulfate production is sensitive to the amount of ozone present to oxidize S

  16. Remote Sensing Soil Salinity Map for the San Joaquin Vally, California

    Science.gov (United States)

    Scudiero, E.; Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.

    2015-12-01

    Soil salinization is a major natural hazard to worldwide agriculture. We present a remote imagery approach that maps salinity within a range (i.e., salinities less than 20 dS m-1, when measured as the electrical conductivity of the soil saturation extract), accuracy, and resolution most relevant to agriculture. A case study is presented for the western San Joaquin Valley (WSJV), California, USA (~870,000 ha of farmland) using multi-year Landsat 7 ETM+ canopy reflectance and the Canopy Response Salinity Index (CRSI). Highly detailed salinity maps for 22 fields (542 ha) established from apparent soil electrical conductivity directed sampling were used as ground-truth (sampled in 2013), totaling over 5000 pixels (30×30 m) with salinity values in the range of 0 to 35.2 dS m-1. Multi-year maximum values of CRSI were used to model soil salinity. In addition, soil type, elevation, meteorological data, and crop type were evaluated as covariates. The fitted model (R2=0.73) was validated: i) with a spatial k-folds (i.e., leave-one-field-out) cross-validation (R2=0.61), ii) versus salinity data from three independent fields (sampled in 2013 and 2014), and iii) by determining the accuracy of the qualitative classification of white crusted land as extremely-saline soils. The effect of land use change is evaluated over 2396 ha in the Broadview Water District from a comparison of salinity mapped in 1991 with salinity predicted in 2013 from the fitted model. From 1991 to 2013 salinity increased significantly over the selected study site, bringing attention to potential negative effects on soil quality of shifting from irrigated agriculture to fallow-land. This is cause for concern since over the 3 years of California's drought (2010-2013) the fallow land in the WSJV increased from 12.7% to 21.6%, due to drastic reduction in water allocations to farmers.

  17. Bathymetric survey and digital elevation model of Little Holland Tract, Sacramento-San Joaquin Delta, California

    Science.gov (United States)

    Snyder, Alexander G.; Lacy, Jessica R.; Stevens, Andrew W.; Carlson, Emily M.

    2016-06-10

    The U.S. Geological Survey conducted a bathymetric survey in Little Holland Tract, a flooded agricultural tract, in the northern Sacramento-San Joaquin Delta (the “Delta”) during the summer of 2015. The new bathymetric data were combined with existing data to generate a digital elevation model (DEM) at 1-meter resolution. Little Holland Tract (LHT) was historically diked off for agricultural uses and has been tidally inundated since an accidental levee breach in 1983. Shallow tidal regions such as LHT have the potential to improve habitat quality in the Delta. The DEM of LHT was developed to support ongoing studies of habitat quality in the area and to provide a baseline for evaluating future geomorphic change. The new data comprise 138,407 linear meters of real-time-kinematic (RTK) Global Positioning System (GPS) elevation data, including both bathymetric data collected from personal watercraft and topographic elevations collected on foot at low tide. A benchmark (LHT15_b1) was established for geodetic control of the survey. Data quality was evaluated both by comparing results among surveying platforms, which showed systematic offsets of 1.6 centimeters (cm) or less, and by error propagation, which yielded a mean vertical uncertainty of 6.7 cm. Based on the DEM and time-series measurements of water depth, the mean tidal prism of LHT was determined to be 2,826,000 cubic meters. The bathymetric data and DEM are available at http://dx.doi.org/10.5066/F7RX9954. 

  18. GPS-seismograms reveal amplified shaking in California's San Joaquin Delta region

    Science.gov (United States)

    Johanson, I. A.

    2014-12-01

    The March 10, 2014, the Mw6.8 Ferndale earthquake occurred off the coast of Northern California, near the Mendocino Triple Junction. Aftershocks suggest a northeast striking fault plane for the strike-slip earthquake, oriented such that the California coast is roughly perpendicular to the rupture plane. Consequently, large amplitude Love waves were observed at seismic stations and continuous GPS stations throughout Northern California. While GPS is less sensitive then broadband instruments, in Northern California their station density is much higher, potentially providing valuable detail. A total of 269 GPS stations that have high-rate (1 sps) data available were used to generate GPS-seismograms. These include stations from the Bay Area Regional Deformation (BARD) network, the Plate Boundary Observatory (PBO, operated by UNAVCO), and the USGS, Menlo Park. The Track software package was used to generate relative displacements between pairs of stations, determined using Delaunay triangulation. This network-based approach allows for higher precision than absolute positioning, because common noise sources, in particular atmospheric noise, are cancelled out. A simple least-squares network adjustment with a stable centroid constraint is performed to transform the mesh of relative motions into absolute motions at individual GPS stations. This approach to generating GPS-seismograms is validated by the good agreement between time series records at 16 BARD stations that are co-located with broadband seismometers from the Berkeley Digital Seismic Network (BDSN). While the distribution of peak dynamic displacements is dominated in long periods by the radiation pattern, at shorter periods other patterns become visible. In particular, stations in the San Joaquin Delta (SJD) region show higher peak dynamic displacements than those in surrounding areas, as well as longer duration shaking. SJD stations also have higher dynamic displacements on the radial component than surrounding

  19. Groundwater quality in the shallow aquifers of the Madera–Chowchilla and Kings subbasins, San Joaquin Valley, California

    Science.gov (United States)

    Fram, Miranda S.; Shelton, Jennifer L.

    2018-01-08

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Program’s Priority Basin Project assesses the quality of groundwater resources used for drinking-water supply and increases public access to groundwater-quality information. Many households and small communities in the Madera– Chowchilla and Kings subbasins of the San Joaquin Valley rely on private domestic wells for their drinking-water supplies.

  20. Invasive Plants (poly) - Red Sesbania - San Joaquin River [ds633

    Data.gov (United States)

    California Natural Resource Agency — The purpose of this work is to estimate the occurrence, distribution, approximate locations, and abundance of red sesbania (Sesbania punicea) and four other major...

  1. Site Response and Basin Waves in the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Fletcher, Jon Peter B.; Boatwright, John

    2013-01-01

    The Sacramento–San Joaquin Delta is an inland delta at the western extent of the Central Valley. Levees were built around swampy islands starting after the Civil War to reclaim these lands for farming. Various studies show that these levees could fail in concert from shaking from a major local or regional earthquake resulting in salty water from the San Francisco Bay contaminating the water in the Delta. We installed seismographs around the Delta and on levees to assess the contribution of site response to the seismic hazard of the levees. Cone penetrometer testing shows that the upper 10 s of meters of soil in the Delta have shear‐wave velocities of about 200  m/s, which would give a strong site response. Seismographs were sited following two strategies: pairs of stations to compare the response of the levees to nearby sites, and a more regional deployment in the Delta. Site response was determined in two different ways: a traditional spectral ratio (TSR) approach of S waves using station BDM of the Berkeley Digital Seismic Net as a reference site, and using SH/SV ratios of noise (or Nakamura’s method). Both estimates usually agree in spectral character for stations whose response is dominated by a resonant peak, but the most obvious peaks in the SH/SV ratios usually are about two‐thirds as large as the main peaks in the TSRs. Levee sites typically have large narrow resonances in the site response function compared to sites in the farmland of the Delta. These resonances, at a frequency of about 1–3 Hz, have amplitudes of about 15 with TSR and 10–12 with Nakamura’s method. Sites on farmland in the Delta also have amplifications, but these are typically broader and not as resonant in appearance. Late (slow) Rayleigh waves were recorded at stations in the Delta, have a dominant period of about one second, and are highly monochromatic. Results from a three‐station array at the Holland Marina suggest that they have a phase velocity of about

  2. Levee Seepage Detection in the Sacramento-San Joaquin Delta Using Polarimetric SAR

    Science.gov (United States)

    An, K.; Jones, C. E.; Bekaert, D. P.

    2017-12-01

    The Sacramento-San Joaquin Delta's extensive levee system protects over 2,800 km2 of reclaimed lands and serves as the main irrigation and domestic water supply for the state of California. However, ongoing subsidence and disaster threats from floods and earthquakes make the Delta levee system highly vulnerable, endangering water supplies for 23 million California residents and 2.5 million acres of agricultural land. Levee failure in the Delta can cause saltwater intrusion from San Francisco Bay, reducing water quality and curtailing water exports to residents, commercial users, and farmers. To protect the Delta levee system, it is essential to search for signs of seepage in which water is piping through or beneath levees, which can be associated with deformation of the levees themselves. Until now, in-situ monitoring has largely been applied, however, this is a time-consuming and expensive approach. We use data acquired with NASA's UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) airborne radar instrument to identify and characterize levee seepages and associated land subsidence through advanced remote sensing technologies. The high spatial resolution of UAVSAR can help to direct surveys to areas that are likely to be experiencing damage. UAVSAR is an L-band airborne sensor with high signal-to-noise ratio, repeat flight track accuracy, and spatial resolution of 7x7 m2 (for multi-looked products) that is necessary for detailed levee monitoring. The adaptability of radar instruments in their ability to see through smoke, haze, and clouds during the day or night, is especially relevant during disaster events, when cloud cover or lack of solar illumination inhibits traditional visual surveys of damage. We demonstrate the advantages of combining polarimetric radar imagery with geographic information systems (GIS) datasets in locating seepage features along critical levee infrastructure in the Delta for 2009-2016. The ability to efficiently locate potential

  3. Landsat-based monitoring of crop water demand in the San Joaquin Valley

    Science.gov (United States)

    Johnson, L.; Trout, T.; Wang, D.; Melton, F. S.

    2010-12-01

    Fresh water resources are becoming increasingly scarce in California due to urbanization, environmental regulation, and groundwater depletion. The strain is projected to worsen under various climate change scenarios and is exacerbated by declining water delivery infrastructure. It is estimated that irrigated agriculture currently commands more than 70% of the state’s water supply, and many growers are striving to improve water use efficiency in order to help maintain the state’s rich agricultural heritage. Remote sensing technology offers the potential to monitor cropland evapotranspiration (ET) regionally, while making farm-based irrigation scheduling more practical, convenient, and possibly more accurate. Landsat5-TM imagery was used in this study to monitor basal crop evapotranspiration (ETcb), which is primarily related to plant transpiration, for several San Joaquin Valley fields throughout the 2008 growing season. A ground-based digital camera was used to measure fractional cover of 48 study fields planted to 18 different crop types (row crops, grains, orchard, and vineyard) of varying maturity over 12 dates coinciding with Landsat overpasses. Landsat L1T terrain-corrected images were atmospherically corrected to surface reflectance by an implementation of the Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS), then converted to normalized difference vegetation index (NDVI) on a per-pixel basis. A strong linear relationship between NDVI and fractional cover was observed (r2=0.96), and a resulting conversion equation was used to transform all imagery to fractional cover. Conversion equations previously developed by use of weighting lysimeters were then used to transform fractional cover to basal crop coefficient (Kcb; ratio of crop transpiration plus a small diffusive soil evaporation component to reference ET). Finally, measurements of grass reference ET (ETo) from the California Irrigation Management Information System were used to

  4. Challenges Facing the Sacramento–San Joaquin Delta: Complex, Chaotic, or Simply Cantankerous?

    Directory of Open Access Journals (Sweden)

    Samuel N. Luoma

    2015-09-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss3art7Freshwater is a scarce and precious resource in California; its overall value is being made clear by the current severe drought. The Sacramento–San Joaquin Delta is a critical node in a complex water supply system that extends throughout much of the western U.S. wherein demand is exceeding supply. The Delta also underpins a major component of the U.S. economy, helps feed a substantial part of the country, is a unique and valuable ecological resource, and is a place with a rich cultural heritage. Sustaining the Delta is a problem that manifests itself in many dimensions including the physical structure of the Delta, the conflicting demands for water, changing water quality, rapidly evolving ecological character, and high institutional complexity. The problems of the California Delta are increasingly complex, sometimes chaotic, and always contentious. There is general agreement that current management will sustain neither the Delta ecosystem nor high-quality water exports, as required under the Delta Reform Act, so there is a renewed urgency to address all dimensions of the problem aggressively. Sustainable management of the Delta ecosystem and California’s highly variable water supply, in the face of global climate change, will require bold political decisions that include adjustments to the infrastructure but give equal emphasis to chronic overuse and misuse of water, promote enhanced efficiency of water use, and facilitate new initiatives for ecosystem recovery. This new approach will need to be underpinned by collaborative science that supports ongoing evaluation and re-adjustment of actions. Problems like the Delta are formally “wicked" problems that cannot be “solved” in the traditional sense, but they can be managed with appropriate knowledge and flexible institutions. Where possible, it is advisable to approach major actions incrementally, with an eye toward avoiding

  5. September-March survival of female northern pintails radiotagged in San Joaquin Valley, California

    Science.gov (United States)

    Fleskes, J.P.; Jarvis, R.L.; Gilmer, D.S.

    2002-01-01

    To improve understanding of pintail ecology, we radiotagged 191 hatch-year (HY) and 228 after-hatch-year (AHY) female northern pintails (Anas acuta) in the San Joaquin Valley (SJV), and studied their survival throughout central California, USA, during September-March, 1991-1994. We used adjusted Akaike Information Criterion (AICc) values to contrast known-fate models and examine variation in survival rates relative to year, interval, wintering region (AJV, other central California), pintail age, body mass at capture, capture date, capture area, and radio type. The best-fitting model included only interval x year and age x body mass; the next 2 best-fitting models also included wintering region and capture date. Hunting caused 83% of the mortalities we observed, and survival was consistently lower during hunting than nonhunting intervals. Nonhunting and hunting mortality during early winter was highest during the 1991-1992 drought year. Early-winter survival improved during the study along with habitat conditions in the Grassland Ecological Area (EA), where most radiotagged pintails spent early winter. Survival was more closely related to body mass at capture for HY than AHY pintails, even after accounting for the later arrival (based on capture date) of HY pintails, suggesting HY pintails are less adept at improving their condition. Thus, productivity estimates based on harvest age ratios may be biased if relative vulnerability of HY and AHY pintails is assumed to be constant because fall body condition of pintails may vary greatly among years. Cumulative winter survival was 75.6% (95% CI = 68.3% to 81.7%) for AHY and 65.4% (56.7% to 73.1%) for HY female pintails. Daily odds of survival in the cotton-agriculture landscape of the SJV were -21.3% (-40.3% to +3.7%) lower than in the rice-agriculture landscape of the Sacramento Valley (SACV) and other central California areas. Higher hunting mortality may be 1 reason pintails have declined more in SJV than in SACV.

  6. Subsidence Reversal in a Re-established Wetland in the Sacramento-San Joaquin Delta, California, USA

    Directory of Open Access Journals (Sweden)

    Robin L. Miller

    2008-10-01

    Full Text Available The stability of levees in the Sacramento-San Joaquin Delta is threatened by continued subsidence of Delta peat islands. Up to 6 meters of land-surface elevation has been lost in the 150 years since Delta marshes were leveed and drained, primarily from oxidation of peat soils. Flooding subsided peat islands halts peat oxidation by creating anoxic soils, but net accumulation of new material in restored wetlands is required to recover land-surface elevations. We investigated the subsidence reversal potential of two 3 hectare, permanently flooded, impounded wetlands re-established on a deeply subsided field on Twitchell Island. The shallower wetland (design water depth 25 cm was almost completely colonized by dense emergent marsh vegetation within two years; whereas, the deeper wetland (design water depth 55 cm which developed spatially variable depths as a result of heterogeneous colonization by emergent vegetation, still had some areas remaining as open water after nine years. Changes in land-surface elevation were quantified using repeated sedimentation-erosion table measurements. New material accumulating in the wetlands was sampled by coring. Land-surface elevations increased by an average of 4 cm/yr in both wetlands from 1997 to 2006; however, the rates at different sites in the wetlands ranged from -0.5 to +9.2 cm/yr. Open water areas of the deeper wetland without emergent vegetation had the lowest rates of land-surface elevation gain. The greatest rates occurred in areas of the deeper wetland most isolated from the river water inlets, with dense stands of emergent marsh vegetation (tules and cattails. Vegetated areas of the deeper wetland in the transition zones between open water and mature emergent stands had intermediate rates of land-surface gain, as did the entire shallower wetland. These results suggest that the dominant component contributing to land-surface elevation gain in these wetlands was accumulation of organic matter, rather

  7. Land subsidence along the Delta-Mendota Canal in the northern part of the San Joaquin Valley, California, 2003-10

    Science.gov (United States)

    Sneed, Michelle; Brandt, Justin; Solt, Mike

    2013-01-01

    seasonal periods of subsidence and of uplift that resulted in little or no longer-term elevation loss. Many groundwater levels in this northern area did not reach historical lows during 2003–10, indicating that deformation in this region was primarily elastic. Although the northern portion of the Delta-Mendota Canal was relatively stable, land-surface deformation measurements indicated the southern portion of the Delta-Mendota Canal (Checks 15–21) subsided as part of a large subsidence feature centered about 15 kilometers northeast of the Delta-Mendota Canal, south of the town of El Nido. Results of InSAR analysis indicated at least 540 millimeters of subsidence near the San Joaquin River and the Eastside Bypass during 2008–10, which is part of a 3,200 square-kilometer area—including the southern part of the Delta-Mendota Canal—affected by 20 millimeters or more of subsidence during the same period. Calculations indicated that the subsidence rate doubled in 2008 in some areas. The GPS surveys done in 2008 and 2010 confirmed the high subsidence rate measured by using InSAR for the same period. Water levels in many shallow and deep wells in this area declined during 2007–10; water levels in many deep wells reached historical lows, indicating that subsidence measured during this period was largely inelastic. InSAR-derived subsidence maps for various periods during 2003–10 showed that the area of maximum active subsidence (that is, the largest rates of subsidence) shifted from its historical (1926–70) location southwest of Mendota to south of El Nido. Continued groundwater-level and land-subsidence monitoring in the San Joaquin Valley is important because (1) regulatory- and drought-related reductions in surface-water deliveries since 1976 have resulted in increased groundwater pumping and associated land subsidence, and (2) land use and associated groundwater pumping continue to change throughout the valley. The availability of surface water remains uncertain

  8. Control strategies for the reduction of airborne particulate nitrate in California's San Joaquin Valley

    Science.gov (United States)

    Kleeman, Michael J.; Ying, Qi; Kaduwela, Ajith

    The effect of NO x, volatile organic compound (VOC), and NH 3 emissions control programs on the formation of particulate ammonium nitrate in the San Joaquin Valley (SJV) was examined under the typical winter conditions that existed on 4-6 January, 1996. The UCD/CIT photochemical transport model was used for this study so that the source origin of primary particulate matter and secondary particulate matter could be identified. When averaged across the entire SJV, the model results predict that 13-18% of the reactive nitrogen (NO y=NO x+reaction products of NO x) emitted from local sources within the SJV was converted to nitrate at the ground level. Each gram of NO x emitted locally within the SJV (expressed as NO 2) produced 0.23-0.31 g of particulate ammonium nitrate (NH 4NO 3), which is much smaller than the maximum theoretical yield of 1.7 g of NH 4NO 3 per gram of NO 2. The fraction of reactive nitrogen converted to nitrate varied strongly as a function of location. Urban regions with large amounts of fresh NO emissions converted little reactive nitrogen to nitrate, while remote areas had up to 70% conversion (equivalent to approximately 1.2 g of NH 4NO 3 per gram of NO 2). The use of a single spatially averaged ratio of NH 4NO 3/NO x as a predictor of how changes to NO x emissions would affect particulate nitrate concentrations would not be accurate at all locations in the SJV under the conditions studied. The largest local sources of particulate nitrate in the SJV were predicted to be diesel engines and catalyst equipped gasoline engines under the conditions experienced on 6 January, 1996. Together, these sources accounted for less than half of the ground-level nitrate aerosol in the SJV. The remaining fraction of the aerosol nitrate originated from reactive nitrogen originally released upwind of the SJV. The majority of this upwind reactive nitrogen was already transformed to nitrate by the time it entered the SJV. The effect of local emissions controls on

  9. Assessing the solubility controls on vanadium in groundwater, northeastern San Joaquin Valley, CA

    Science.gov (United States)

    Wright, Michael T.; Stollenwerk, Kenneth G.; Belitz, Kenneth

    2014-01-01

    The solubility controls on vanadium (V) in groundwater were studied due to concerns over possible harmful health effects of ingesting V in drinking water. Vanadium concentrations in the northeastern San Joaquin Valley ranged from 25 μg/L) and lowest in samples collected from anoxic groundwater (70% 2VO4−. Adsorption/desorption reactions with mineral surfaces and associated oxide coatings were indicated as the primary solubility control of V5+ oxyanions in groundwater. Environmental data showed that V concentrations in oxic groundwater generally increased with increasing groundwater pH. However, data from adsorption isotherm experiments indicated that small variations in pH (7.4–8.2) were not likely as an important a factor as the inherent adsorption capacity of oxide assemblages coating the surface of mineral grains. In suboxic groundwater, accurate SM modeling was difficult since Eh measurements of source water were not measured in this study. Vanadium concentrations in suboxic groundwater decreased with increasing pH indicating that V may exist as an oxycationic species [e.g. V(OH)3+]. Vanadium may complex with dissolved inorganic and organic ligands under suboxic conditions, which could alter the adsorption behavior of V in groundwater. Speciation modeling did not predict the existence of V-inorganic ligand complexes and organic ligands were not collected as part of this study. More work is needed to determine processes governing V solubility under suboxic groundwater conditions. Under anoxic groundwater conditions, SM predicts that aqueous V exists as the uncharged V(OH)3 molecule. However, exceedingly low V concentrations show that V is sparingly soluble in anoxic conditions. Results indicated that V may be precipitating as V3+- or mixed V3+/Fe3+-oxides in anoxic groundwater, which is consistent with results of a previous study. The fact that V appears insoluble in anoxic (Fe reducing) redox conditions indicates that the behavior of V is different than

  10. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, 76703 Queretaro (Mexico); Hernandez, G.; Solis, S. [UNAM, Campus Juriquilla, Centro de Geociencias, Boulevard Juriquilla 3001, 76230 Queretaro (Mexico); Garcia, R. [UNAM, Centro de Ciencias de la Atmosfera, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Pi, T., E-mail: ebustos@cideteq.mx [UNAM, Instituto de Geologia, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2014-07-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  11. Childhood asthma, air quality, and social suffering among Mexican Americans in California's San Joaquin Valley: "Nobody talks to us here".

    Science.gov (United States)

    Schwartz, Norah Anita; Pepper, David

    2009-10-01

    Nearly one in five Mexican American children residing in California's San Joaquin Valley (the Valley) in 2007 had an asthma attack at some point in their life. Numerous epidemiological studies have suggested that compared with other ethnic groups and Latino subgroups residing in the United States, Mexican origin children have the lowest rates of pediatric asthma. Ethnographic research conducted in central California, however, suggests otherwise. Known for its agricultural produce, extreme poverty, and poor air quality, the Valley is a magnet for the Mexican immigrant farm worker population. We conducted an exploratory ethnographic study to examine health disparities, social suffering, and childhood asthma in the Valley. Many Valley residents believe that their children's health concerns are being ignored. Open-ended interviews uncovered a largely rural community suffering not only from the effects of childhood asthma but the inability to have their experiences taken seriously.

  12. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    International Nuclear Information System (INIS)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E.; Hernandez, G.; Solis, S.; Garcia, R.; Pi, T.

    2014-01-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  13. Factors motivating Latino college students to pursue STEM degrees on CSU campuses in the southern San Joaquin Valley

    Science.gov (United States)

    Ramirez, Gabriel

    The purpose of this study was to determine what factors were motivating Latino/a students in the southern San Joaquin Valley to pursue STEM degrees and whether these factors were specific to the Latino/a culture. A 12-question survey was administered to STEM majors at California State University, Bakersfield and California State University, Fresno and interviews were conducted with those survey respondents who agreed to be part of the process. The results of the survey suggested that factors such as STEM subject matter, STEM career knowledge, the possibility of a high paying salary, high school STEM grades, and family influence were significant in motivating Latino/a students to pursue STEM degrees. The results of the Chi Square Test suggested the Latino/a students' responses about college STEM degree granting statistics, the possibility of a high salary, and the effects of setbacks were significantly different to those of their non-Latino/a counterparts.

  14. Persistence of historical population structure in an endangered species despite near-complete biome conversion in California's San Joaquin Desert.

    Science.gov (United States)

    Richmond, Jonathan Q; Wood, Dustin A; Westphal, Michael F; Vandergast, Amy G; Leaché, Adam D; Saslaw, Lawrence R; Butterfield, H Scott; Fisher, Robert N

    2017-07-01

    Genomic responses to habitat conversion can be rapid, providing wildlife managers with time-limited opportunities to enact recovery efforts that use population connectivity information that reflects predisturbance landscapes. Despite near-complete biome conversion, such opportunities may still exist for the endemic fauna and flora of California's San Joaquin Desert, but comprehensive genetic data sets are lacking for nearly all species in the region. To fill this knowledge gap, we studied the rangewide population structure of the endangered blunt-nosed leopard lizard Gambelia sila, a San Joaquin Desert endemic, using restriction site-associated DNA (RAD), microsatellite and mtDNA data to test whether admixture patterns and estimates of effective migration surfaces (EEMS) can identify land areas with high population connectivity prior to the conversion of native xeric habitats. Clustering and phylogenetic analyses indicate a recent shared history between numerous isolated populations and EEMS reveals latent signals of corridors and barriers to gene flow over areas now replaced by agriculture and urbanization. Conflicting histories between the mtDNA and nuclear genomes are consistent with hybridization with the sister species G. wislizenii, raising important questions about where legal protection should end at the southern range limit of G. sila. Comparative analysis of different data sets also adds to a growing list of advantages in using RAD loci for genetic studies of rare species. We demonstrate how the results of this work can serve as an evolutionary guidance tool for managing endemic, arid-adapted taxa in one of the world's most compromised landscapes. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  15. Persistence of historical population structure in an endangered species despite near-complete biome conversion in California's San Joaquin Desert

    Science.gov (United States)

    Richmond, Jonathan Q.; Wood, Dustin A.; Westphal, Michael F.; Vandergast, Amy; Leache, Adam D.; Saslaw, Lawrence; Butterfield, H. Scott; Fisher, Robert N.

    2017-01-01

    Genomic responses to habitat conversion can be rapid, providing wildlife managers with time-limited opportunities to enact recovery efforts that use population connectivity information that reflects predisturbance landscapes. Despite near-complete biome conversion, such opportunities may still exist for the endemic fauna and flora of California's San Joaquin Desert, but comprehensive genetic data sets are lacking for nearly all species in the region. To fill this knowledge gap, we studied the rangewide population structure of the endangered blunt-nosed leopard lizard Gambelia sila, a San Joaquin Desert endemic, using restriction site-associated DNA (RAD), microsatellite and mtDNA data to test whether admixture patterns and estimates of effective migration surfaces (EEMS) can identify land areas with high population connectivity prior to the conversion of native xeric habitats. Clustering and phylogenetic analyses indicate a recent shared history between numerous isolated populations and EEMS reveals latent signals of corridors and barriers to gene flow over areas now replaced by agriculture and urbanization. Conflicting histories between the mtDNA and nuclear genomes are consistent with hybridization with the sister species G. wislizenii, raising important questions about where legal protection should end at the southern range limit of G. sila. Comparative analysis of different data sets also adds to a growing list of advantages in using RAD loci for genetic studies of rare species. We demonstrate how the results of this work can serve as an evolutionary guidance tool for managing endemic, arid-adapted taxa in one of the world's most compromised landscapes.

  16. Mapping deep aquifer salinity trends in the southern San Joaquin Valley using borehole geophysical data constrained by chemical analyses

    Science.gov (United States)

    Gillespie, J.; Shimabukuro, D.; Stephens, M.; Chang, W. H.; Ball, L. B.; Everett, R.; Metzger, L.; Landon, M. K.

    2016-12-01

    The California State Water Resources Control Board and the California Division of Oil, Gas and Geothermal Resources are collaborating with the U.S. Geological Survey to map groundwater resources near oil fields and to assess potential interactions between oil and gas development and groundwater resources. Groundwater resources having salinity less than 10,000 mg/L total dissolved solids may be classified as Underground Sources of Drinking Water (USDW) and subject to protection under the federal Safe Drinking Water Act. In this study, we use information from oil well borehole geophysical logs, oilfield produced water and groundwater chemistry data, and three-dimensional geologic surfaces to map the spatial distribution of salinity in aquifers near oil fields. Salinity in the southern San Joaquin Valley is controlled primarily by depth and location. The base of protected waters occurs at very shallow depths, often 1,500 meters, in the eastern part of the San Joaquin Valley where higher runoff from the western slopes of the Sierra Nevada provide relatively abundant aquifer recharge. Stratigraphy acts as a secondary control on salinity within these broader areas. Formations deposited in non-marine environments are generally fresher than marine deposits. Layers isolated vertically between confining beds and cut off from recharge sources may be more saline than underlying aquifers that outcrop in upland areas on the edge of the valley with more direct connection to regional recharge areas. The role of faulting is more ambiguous. In some areas, abrupt changes in salinity may be fault controlled but, more commonly, the faults serve as traps separating oil-bearing strata that are exempt from USDW regulations, from water-bearing strata that are not exempt.

  17. 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

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

    Science.gov (United States)

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

    2016-01-01

    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 fresh water 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 were stacked over 8 months to more than a year. Dispersion curves were determined from 4 to about 18 seconds. 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 is 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 degrees. 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 cross cutting features like the Stockton arch. At shorter periods around 5.5s, 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

  19. Timber resource statistics for the San Joaquin and southern California resource areas.

    Science.gov (United States)

    Bruce Hiserote; Joel Moen; Charles L. Bolsinger

    1986-01-01

    This report is one of five that provide timber resource statistics for 57 of the 58 counties in California (San Francisco is excluded). This report presents statistics from a 1982-84 inventory of the timber resources of Alpine, Amador, Calaveras, Fresno, Imperial, Inyo, Kern, Kings, Los Angeles, Madera, Mariposa, Merced, Mono, Orange, Riverside, San Bernardino, San...

  20. Late Holocene forest dynamics, volcanism, and climate change at Whitewing Mountain and San Joaquin Ridge, Mono County, Sierra Nevada, CA, USA

    Science.gov (United States)

    Constance I. Millar; John C. King; Robert D. Westfall; Harry A. Alden; Diane L. Delany

    2006-01-01

    Deadwood tree stems scattered above treeline on tephra-covered slopes of Whitewing Mtn (3051 m) and San Joaquin Ridge (3122 m) show evidence of being killed in an eruption from adjacent Glass Creek Vent, Inyo Craters. Using tree-ring methods, we dated deadwood to AD 815-1350 and infer from death dates that the eruption occurred in late summer AD 1350. Based on wood...

  1. Formation of hydroxyl radical from San Joaquin Valley particles extracted in a cell-free surrogate lung fluid

    Directory of Open Access Journals (Sweden)

    H. Shen

    2011-09-01

    Full Text Available Previous studies have suggested that the adverse health effects from ambient particulate matter (PM are linked to the formation of reactive oxygen species (ROS by PM in cardiopulmonary tissues. While hydroxyl radical (OH is the most reactive of the ROS species, there are few quantitative studies of OH generation from PM. Here we report on OH formation from PM collected at an urban (Fresno and rural (Westside site in the San Joaquin Valley (SJV of California. We quantified OH in PM extracts using a cell-free, phosphate-buffered saline (PBS solution with or without 50 μM ascorbate (Asc. The results show that generally the urban Fresno PM generates much more OH than the rural Westside PM. The presence of Asc at a physiologically relevant concentration in the extraction solution greatly enhances OH formation from all the samples. Fine PM (PM2.5 generally makes more OH than the corresponding coarse PM (PMcf, i.e. with diameters of 2.5 to 10 μm normalized by air volume collected, while the coarse PM typically generates more OH normalized by PM mass. OH production by SJV PM is reduced on average by (97 ± 6 % when the transition metal chelator desferoxamine (DSF is added to the extraction solution, indicating a dominant role of transition metals. By measuring calibration curves of OH generation from copper and iron, and quantifying copper and iron concentrations in our particle extracts, we find that PBS-soluble copper is primarily responsible for OH production by the SJV PM, while iron often makes a significant contribution. Extrapolating our results to expected burdens of PM-derived OH in human lung lining fluid suggests that typical daily PM exposures in the San Joaquin Valley are unlikely to result in a high amount of pulmonary OH, although high

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

    Science.gov (United States)

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

    2013-01-01

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

  3. Decision analysis framing study; in-valley drainage management strategies for the western San Joaquin Valley, California

    Science.gov (United States)

    Presser, Theresa S.; Jenni, Karen E.; Nieman, Timothy; Coleman, James

    2010-01-01

    Constraints on drainage management in the western San Joaquin Valley and implications of proposed approaches to management were recently evaluated by the U.S. Geological Survey (USGS). The USGS found that a significant amount of data for relevant technical issues was available and that a structured, analytical decision support tool could help optimize combinations of specific in-valley drainage management strategies, address uncertainties, and document underlying data analysis for future use. To follow-up on USGS's technical analysis and to help define a scientific basis for decisionmaking in implementing in-valley drainage management strategies, this report describes the first step (that is, a framing study) in a Decision Analysis process. In general, a Decision Analysis process includes four steps: (1) problem framing to establish the scope of the decision problem(s) and a set of fundamental objectives to evaluate potential solutions, (2) generation of strategies to address identified decision problem(s), (3) identification of uncertainties and their relationships, and (4) construction of a decision support model. Participation in such a systematic approach can help to promote consensus and to build a record of qualified supporting data for planning and implementation. In December 2008, a Decision Analysis framing study was initiated with a series of meetings designed to obtain preliminary input from key stakeholder groups on the scope of decisions relevant to drainage management that were of interest to them, and on the fundamental objectives each group considered relevant to those decisions. Two key findings of this framing study are: (1) participating stakeholders have many drainage management objectives in common; and (2) understanding the links between drainage management and water management is necessary both for sound science-based decisionmaking and for resolving stakeholder differences about the value of proposed drainage management solutions. Citing

  4. Mercury in the mix: An in situ mesocosm approach to assess relative contributions of mercury sources to methylmercury production and bioaccumulation in the Sacramento-San Joaquin Delta

    Science.gov (United States)

    Fleck, J.; Krabbenhoft, D. P.; Kraus, T. E. C.; Ackerman, J.; Stumpner, E. B.; DeWild, J.; Marvin-DiPasquale, M. C.; Tate, M.; Ogorek, J.

    2014-12-01

    Mercury (Hg) contamination is considered one of the greatest threats to the Sacramento-San Joaquin Delta and the San Francisco Estuary ecosystems. This threat is driven by the transformation of Hg, deposited in the Delta from erosion of upstream historic mining debris and atmospheric deposition, by native bacteria into the more toxic and biologically available form, methylmercury (MeHg), in the wetlands and sediment of the Delta. To effectively manage this threat, a quantitative understanding of the relative contribution of the different Hg sources to MeHg formation is needed. Mass balance estimates indicate as much as 99% of the Hg entering the Delta arrives via tributary inputs. Of the tributary Hg load, approximately 90% is adsorbed to suspended particles from tributary discharge and 10% is in the dissolved fraction, potentially of atmospheric origin. In comparison, the remaining 1-2% of the Hg entering the Delta arrives through direct atmospheric deposition (wet and dry). The relative importance of these sources to MeHg production within the Delta is not linearly related to the mass inputs because atmospherically-derived Hg is believed to be more reactive than sediment-bound Hg with respect to MeHg formation. We conducted an in situ mesocosm dosing experiment where different Hg sources to the Delta (direct atmospheric, dissolved riverine and suspended sediment) were "labeled" with different stable Hg isotopes and added to mesocosms within four different wetlands. Mercury isotopes added with the streambed sediments were equilibrated in sealed containers for six months; while the Hg isotopes associated with the precipitation and river water were equilibrated for 24 hours prior to use. After adding the isotopes, we sampled the water column, overlying air, bottom sediments and fish (Gambusia) at time intervals up to 30 days. Preliminary results from this experiment suggest that aqueous Hg sources (Hg introduced with precipitation and filtered river water) are 10

  5. High Frequency Monitoring of Isotopic Signatures Elucidates Potential Effects of Restoring Floodplain Habitat in the Sacramento-San Joaquin Delta, California, USA

    Science.gov (United States)

    Nakamoto, B. J.; Fogel, M. L.; Jeffres, C.; Viers, J. H.

    2017-12-01

    Increasing the quality and quantity of habitat for native species in the Sacramento-San Joaquin Delta is a high priority for California water managers. The McCormack-Williamson Tract (MWT) is a subsided island (38.253° N -121.284° W) situated at the confluence of the Cosumnes and Mokelumne rivers, near the inland extent of tidal influence. MWT experienced unexpected levee failure on February 11, 2017, during the wettest year of record for the Mokelumne-Cosumnes river system, which provided a unique opportunity to examine the potential trajectory of future restoration actions within the Delta. We carried out high frequency sampling (n=32, 13% of days) of suspended particulate organic matter (SPOM) and waters in the Mokelumne and Cosumnes river systems, including nearby sloughs, and the post-failure, flooded interior of MWT. Carbon (δ13C) and nitrogen (δ15N) isotopes in SPOM and δ2H and δ18O of waters were analyzed and in situ water quality data were collected in tandem, thus contextualizing isotopic data. Sampling was confined to an 8 km2 region surrounding MWT (6.7 km2 interior). This unintentional flooding provided a natural before-after-control-impact experiment to study the effect that sudden inundation of a Delta island can have on food web development and ecosystem function. Source waters were isotopically distinct (p0.9), providing a semi-conservative tracer of mixing. The δ13C values of SPOM varied between -37.3 and -23.9‰ and were significantly more negative on the flooded island by 1.2‰ (porganic carbon concomitant with accelerated ecosystem metabolism. Concurrently, δ15N values varied between 1.0 and 12.4‰ and were not significantly different between riverine and flooded island sites. Our data indicate that this river system is highly dynamic over short periods of flood inundation (13 weeks) with new freshwater habitats exhibiting higher productivity than their riverine counterparts and could therefore increase autochthonous subsidies to

  6. Phenology of spotted wing drosophila in the San Joaquin Valley varies by season, crop and nearby vegetation

    Directory of Open Access Journals (Sweden)

    David R. Haviland

    2016-01-01

    Full Text Available The spotted wing drosophila, first detected in California in 2008, has become a major insect pest in caneberries and sweet cherries, causing commercial crop losses. Managing it is challenging because it has many other hosts, including riparian and backyard fruit plantings, and it increases rapidly, with generations overlapping one another. In our study we monitored trap captures in two parts of the San Joaquin Valley, within sweet cherry orchards and in nearby locations. Captures of adult flies showed two main periods of activity — spring and fall — and low captures in the winter (except for citrus and evergreen riparian areas and summer. On many occasions during the year, trap captures were higher outside of the cherry orchards than within them. Additionally, early in the season, when decisions about control programs are being made, the sex ratio of captured flies in cherries was strongly female-biased. The results suggest that during the weeks leading up to harvest growers should experiment by placing traps in different environments surrounding their orchards to determine SWD activity and potential pest pressure locally, and monitor for both male and female flies.

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

    International Nuclear Information System (INIS)

    Duff, M.C.; Amrhein, C.; Bradford, G.

    1997-01-01

    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:HCO 3 ratios. Pond algal U bioaccumulation was favored in waters with high Ca:HCO 3 ratios, which had lower pH values and carbonate alkalinities than waters with low CA:HCO 3 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)

  8. 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.

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

    International Nuclear Information System (INIS)

    Luo Yuzhou; Zhang Xuyang; Liu Xingmei; Ficklin, Darren; Zhang Minghua

    2008-01-01

    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

  10. Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the San Joaquin Valley, California

    Science.gov (United States)

    Brown, L.R.

    1997-01-01

    Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of ??DDT (sum of o,p'- and p, p' forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal- Wallis, p TOC) normalized concentrations were significantly correlated with specific conductance and pH (p TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.

  11. Temporal trends in concentrations of DBCP and nitrate in groundwater in the eastern San Joaquin Valley, California, USA

    Science.gov (United States)

    Burow, K.R.; Dubrovsky, N.M.; Shelton, James L.

    2007-01-01

    Temporal monitoring of the pesticide 1,2-dibromo-3-chloropropane (DBCP) and nitrate and indicators of mean groundwater age were used to evaluate the transport and fate of agricultural chemicals in groundwater and to predict the long-term effects in the regional aquifer system in the eastern San Joaquin Valley, California. Twenty monitoring wells were installed on a transect along an approximate groundwater flow path. Concentrations of DBCP and nitrate in the wells were compared to concentrations in regional areal monitoring networks. DBCP persists at concentrations above the US Environmental Protection Agency's maximum contaminant level (MCL) at depths of nearly 40 m below the water table, more than 25 years after it was banned. Nitrate concentrations above the MCL reached depths of more than 20 m below the water table. Because of the intensive pumping and irrigation recharge, vertical flow paths are dominant. High concentrations (above MCLs) in the shallow part of the regional aquifer system will likely move deeper in the system, affecting both domestic and public-supply wells. The large fraction of old water (unaffected by agricultural chemicals) in deep monitoring wells suggests that it could take decades for concentrations to reach MCLs in deep, long-screened public-supply wells, however. ?? Springer-Verlag 2007.

  12. Effects of lamellae size distributions from 40Ar/39Ar on sedimentary thermo-chronology in the San Joaquin Basin

    International Nuclear Information System (INIS)

    Jepsen, A.-M.; Lerche, I.; Thomsen, R.O.

    1990-01-01

    A model description is provided for the release of 40 Ar/ 39 Ar from detrital microclines which specifically includes the effects of grain size distributions, thus allowing smaller grains to release argon faster than the more retentive larger grains. The model also includes the effects of sedimentary thermal history after burial influencing the pre-depositional 40 Ar/ 30 Ar ratio. Application of the model to the measured age spectra from six depths in the Tejon Block and four in the Basin Block of the San Joaquin Basin demonstrates that the grain size distribution effect plays a major role in masking the extraction of thermal history information from the observed age spectra. In addition, the grain size effect is not systematic with depth, and other competing effects, such as isotopic fractionation of diffusion coefficients, multi-provenance depositional supply, and variable concentrations of 40 Ar and 39 K per microcline at burial deposition time, make the extraction of thermal history information even more difficult. (author)

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

    International Nuclear Information System (INIS)

    Stockwell, W.R.; Watson, J.G.; Robinson, N.F.; Sylte, W.W.

    2000-01-01

    A new method has been developed to assess the aerosol particle formation reactivity of nitrogen oxide (NO x ) 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 NO x 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 NO x was converted to particulate nitrate. The particle equivalent of NO x emissions was found to be on the order of 0.6 g of ammonium nitrate for each gram of NO x emitted (the mass of NO x calculated as NO 2 ). This estimate is in reasonable agreement with an analysis of field measurements made in central California. (author)

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

    Science.gov (United States)

    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 investigated associations. We observed increased odds of neural tube defects when comparing the highest with the lowest quartile of exposure for several pollutants after adjusting for maternal race/ethnicity, education, and multivitamin use. The adjusted odds ratio for neural tube defects among those with the highest carbon monoxide exposure was 1.9 (95% confidence interval: 1.1, 3.2) compared with those with the lowest exposure, and there was a monotonic exposure-response across quartiles. The highest quartile of nitrogen oxide exposure was associated with neural tube defects (adjusted odds ratio = 1.8, 95% confidence interval: 1.1, 2.8). The adjusted odds ratio for the highest quartile of nitrogen dioxide exposure was 1.7 (95% confidence interval: 1.1, 2.7). Ozone was associated with decreased odds of neural tube defects. Our results extend the limited body of evidence regarding air pollution exposure and adverse birth outcomes. PMID:23538941

  15. Blood characteristics of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    Energy Technology Data Exchange (ETDEWEB)

    Standley, W.G.; McCue, P.M.

    1992-09-01

    Hematology, serum chemistry, and prevalence of antibodies against selected, pathogens in a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, in 1989 and 1990. Samples from 18 (10 female, 8 male) adult kit foxes were used to establish normal hematology and serum chemistry values for this population. Average values were all within the normal ranges reported for kit foxes in other locations. Three hematology parameters had significant differences between male and female values; males had higher total white blood cell and neutrophil counts, and lower lymphocyte counts. There were no significant differences between serum chemistry values from male and female foxes. Prevalence of antibodies was determined from serum samples from 47 (26 female, 21 male) adult kit foxes and eight (4 female, 4 male) juveniles. Antibodies were detected against five of the eight pathogens tested: canine parvovirus, Toxoplasma gondii Leptospira interrogans, canine distemper virus, and canine hepatitis virus. Antibodies were not detected against Brucella, canis, Coccidioides immitis, or Yersinia pestis.

  16. 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.

  17. Reproduction of the San Joaquin kit fox (Vulpes velox macrotis) on Camp Roberts Army National Guard Training Site, California

    International Nuclear Information System (INIS)

    Spencer, K.A.; Berry, W.H.; Standley, W.G.; O'Farrell, T.P.

    1992-09-01

    The reproduction of a San Joaquin kit fox population (Vulpes velox macrotis) was investigated at Camp Roberts Army National Guard Training Site, California, from November 1988 through September 1991. Of 38 vixens radiocollared prior to parturition, 12 (32%) were successful in raising pups from conception to the point where pups were observed above ground. No yearling vixens were known tb be reproductively active. The mean litter size during 1989 - 1991 was 3.0 (n = 21, SE = 0.28) and ranged from one to six pups. Both the proportion of vixens successfully raising pups and the mean litter size observed at Camp Roberts during this study were lower than those reported at other locations. Sex ratios of kit fox pups were male biased two of the three years, but did not differ statistically from 1:1 throughout the study. Whelping was estimated to occur between February 15 and March 5. Results of this study support previous reports that kit foxes are primarily monogamous, although one case of polygamy may have occurred. Both the proportion of dispersing radiocollared juveniles (26%) and the mean dispersal distance (5.9 km) of juveniles at Camp Roberts appeared low compared to other locations

  18. Multi-year coupled biogeochemical and biophysical impacts of restoring drained agricultural peatlands to wetlands across the Sacramento-San Joaquin Delta, California, USA.

    Science.gov (United States)

    Hemes, K. S.; Eichelmann, E.; Chamberlain, S.; Knox, S. H.; Oikawa, P.; Sturtevant, C.; Verfaillie, J. G.; Baldocchi, D. D.

    2017-12-01

    Globally, delta ecosystems are critical for human livelihoods, but are at increasingly greater risk of degradation. The Sacramento-San Joaquin River Delta (`Delta') has been subsiding dramatically, losing close to 100 Tg of carbon since the mid 19th century due in large part to agriculture-induced oxidation of the peat soils through drainage and cultivation. Efforts to re-wet the peat soils through wetland restoration are attractive as climate mitigation activities. While flooded wetland systems have the potential to sequester significant amounts of carbon as photosynthesis outpaces aerobic respiration, the highly-reduced conditions can result in significant methane emissions. This study will utilize three years (2014-2016) of continuous, gap-filled, CO2 and CH4 flux data from a mesonetwork of seven eddy covariance towers in the Delta to compute GHG budgets for the restored wetlands and agricultural baseline sites measured. Along with biogeochemical impacts of wetland restoration, biophysical impacts such as changes in reflectance, energy partitioning, and surface roughness, can have significant local to regional impacts on air temperature and heat fluxes. We hypothesize that despite flooded wetlands reducing albedo, wetland land cover will cool the near-surface air temperature due to increased net radiation being preferentially partitioned into latent heat flux and rougher canopy conditions allowing for more turbulent mixing with the atmosphere. This study will investigate the seasonal and diurnal patterns of turbulent energy fluxes and the surface properties that drive them. With nascent policy mechanisms set to compensate landowners and farmers for low emission land use practices beyond reforestation, it is essential that policy mechanisms take into consideration how the biophysical impacts of land use change could drive local to regional-scale climatic perturbations, enhancing or attenuating the biogeochemical impacts.

  19. San Pedro River Aquifer Binational Report

    Science.gov (United States)

    Callegary, James B.; Minjárez Sosa, Ismael; Tapia Villaseñor, Elia María; dos Santos, Placido; Monreal Saavedra, Rogelio; Grijalva Noriega, Franciso Javier; Huth, A. K.; Gray, Floyd; Scott, C. A.; Megdal, Sharon; Oroz Ramos, L. A.; Rangel Medina, Miguel; Leenhouts, James M.

    2016-01-01

    The United States and Mexico share waters in a number of hydrological basins and aquifers that cross the international boundary. Both countries recognize that, in a region of scarce water resources and expanding populations, a greater scientific understanding of these aquifer systems would be beneficial. In light of this, the Mexican and U.S. Principal Engineers of the International Boundary and Water Commission (IBWC) signed the “Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transboundary Aquifer Assessment Program" on August 19, 2009 (IBWC-CILA, 2009). This IBWC “Joint Report” serves as the framework for U.S.-Mexico coordination and dialogue to implement transboundary aquifer studies. The document clarifies several details about the program such as background, roles, responsibilities, funding, relevance of the international water treaties, and the use of information collected or compiled as part of the program. In the document, it was agreed by the parties involved, which included the IBWC, the Mexican National Water Commission (CONAGUA), the U.S. Geological Survey (USGS), and the Universities of Arizona and Sonora, to study two priority binational aquifers, one in the San Pedro River basin and the other in the Santa Cruz River basin. This report focuses on the Binational San Pedro Basin (BSPB). Reasons for the focus on and interest in this aquifer include the fact that it is shared by the two countries, that the San Pedro River has an elevated ecological value because of the riparian ecosystem that it sustains, and that water resources are needed to sustain the river, existing communities, and continued development. This study describes the aquifer’s characteristics in its binational context; however, most of the scientific work has been undertaken for many years by each country without full knowledge of the conditions on the other side of the border. The general objective of this study is to

  20. Nest-site habitat of cavity-nesting birds at the San Joaquin Experimental Range

    Science.gov (United States)

    Kathryn L. Purcell; Jared. Verner

    2008-01-01

    Detailed information about the nesting habitats of birds, including those needed for successful nesting, can provide a better understanding of the ecological factors that permit coexistence of different species and may aid in conservation efforts. From 1989 through 1994, we studied the nesting habitat of secondary cavity-nesting birds in oak woodlands at the San...

  1. Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California

    Science.gov (United States)

    Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble

    2016-06-17

    Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about the capture efficiency of juvenile Chinook salmon (Oncorhynchus tshawytscha) by beach seines. Heterogeneity in capture can occur through unrealistic assumptions of closure and from variation in the probability of capture caused by environmental conditions. We evaluated the assumptions of closure and the influence of environmental conditions on capture efficiency and abundance estimates of Chinook salmon from beach seining within the Sacramento–San Joaquin Delta and the San Francisco Bay. Beach seine capture efficiency was measured using a stratified random sampling design combined with open and closed replicate depletion sampling. A total of 56 samples were collected during the spring of 2014. To assess variability in capture probability and the absolute abundance of juvenile Chinook salmon, beach seine capture efficiency data were fitted to the paired depletion design using modified N-mixture models. These models allowed us to explicitly test the closure assumption and estimate environmental effects on the probability of capture. We determined that our updated method allowing for lack of closure between depletion samples drastically outperformed traditional data analysis that assumes closure among replicate samples. The best-fit model (lowest-valued Akaike Information Criterion model) included the probability of fish being available for capture (relaxed closure assumption), capture probability modeled as a function of water velocity and percent coverage of fine sediment, and abundance modeled as a function of sample area, temperature, and water velocity. Given that beach seining is a ubiquitous sampling technique for

  2. Backwater Flooding in San Marcos, TX from the Blanco River

    Science.gov (United States)

    Earl, Richard; Gaenzle, Kyle G.; Hollier, Andi B.

    2016-01-01

    Large sections of San Marcos, TX were flooded in Oct. 1998, May 2015, and Oct. 2015. Much of the flooding in Oct. 1998 and Oct. 2015 was produced by overbank flooding of San Marcos River and its tributaries by spills from upstream dams. The May 2015 flooding was almost entirely produced by backwater flooding from the Blanco River whose confluence is approximately 2.2 miles southeast of downtown. We use the stage height of the Blanco River to generate maps of the areas of San Marcos that are lower than the flood peaks and compare those results with data for the observed extent of flooding in San Marcos. Our preliminary results suggest that the flooding occurred at locations more than 20 feet lower than the maximum stage height of the Blanco River at San Marcos gage (08171350). This suggest that the datum for either gage 08171350 or 08170500 (San Marcos River at San Marcos) or both are incorrect. There are plans for the U.S. Army Corps of Engineers to construct a Blanco River bypass that will divert Blanco River floodwaters approximately 2 miles farther downstream, but the $60 million price makes its implementation problematic.

  3. Crecimiento y propiedades fisico-mecanicas de la madera de teca (Tectona grandis de 17 anos de edad en San Joaquin de Abangares, Costa Rica

    Directory of Open Access Journals (Sweden)

    Fernando Castro

    2000-01-01

    Full Text Available Growth and physical-mechanical properties of 17 years old teak (Tectona grandis growing in San Joaquin, Abangares, Costa Rica. The national and international market of forest products, from certifieddad. managment forests and plantations, is increasingly more demanding as to the standards and characteristics of high quality. The physicalmecanicas mechanical properties of the teak (Tectona grandis, growing in San Joaqufn de Abangares, Costa Rica, at 30 m and 100 16´ north latitude, are determined according to the ASTM standard Destudiadas 143-83. The physical properties of teak timber studied were: basic specific weight, radial, tangential and volumetric contractions, contraction ratio, dry and green density and point of fiber saturation. The mechanical properties studied were: static flexure, shear, hardness, parallel and perpendicular compression. Also included were comparisons with teak timber harvested in other places and latitudes, as well as other hardwood species. The coefficient of variation of the basic specific weight of the San Joaquin de Abangares teak (3.4% is half that of the Quepos teak (7% and almost one third of the average of 50 species (10%, which is an...

  4. An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California

    Science.gov (United States)

    Kraus, Tamara E.C.; Bergamaschi, Brian A.; Downing, Bryan D.

    2017-07-11

    Executive SummaryThis report is the first in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). This first report provides an introduction to the reasons for and fundamental concepts behind collecting HF measurements, and describes the benefits associated with a real-time, continuous, HF, multi-parameter water quality monitoring station network that is co-located with flow stations. It then provides examples of how HF nutrient measurements have improved our understating of nutrient sources and cycling in aquatic systems worldwide, followed by specific examples from the Delta. These examples describe the ways in which HF instrumentation may be used for both fixed-station and spatial assessments. The overall intent of this document is to describe how HF measurements currently (2017) are being used in the Delta to examine the relationship between nutrient concentrations, nutrient cycling, and aquatic habitat conditions.The second report in the series (Downing and others, 2017) summarizes information about HF nutrient and associated biogeochemical monitoring in the northern Delta. The report synthesizes data available from the nutrient and water quality monitoring network currently operated by the U.S. Geological Survey in this ecologically important region of the Delta. In the report, we present and discuss the available data at various timescales—first, at the monthly, seasonal, and inter-annual timescales; and, second, for comparison, at the tidal and event (for example, storms, reservoir releases, phytoplankton blooms) timescales. As expected, we determined that there is substantial variability in nitrate concentrations at short timescales within hours, but also significant variability at longer timescales such as months or years. This multi-scale, high variability affects calculation of fluxes and loads, indicating that HF

  5. Updates on Water Use of Pistachio Orchards Grown in the San Joaquin Valley of California on Saline Soils

    Science.gov (United States)

    Zaccaria, Daniele; Marino, Giulia; Whiting, Michael; Sanden, Blake; Ferguson, Louise; Lampinen, Bruce; Kent, Eric; Snyder, Richard; Grattan, Stephen; Little, Cayle

    2017-04-01

    Pistachio acreage is rapidly expanding in California thanks to its economic profitability and capacity to grow and produce in salt-affected soils. Our team at University of California is updating information on actual water use (ET) of mature pistachio orchards grown on saline soils under micro-irrigation methods. Actual Evapotranspiration (ETa) and Crop Coefficients (Ka) were determined for the 2015 and 2016 crop seasons on four pistachio orchards grown in the San Joaquin Valley (SJV) on grounds with increasing levels of soil-water salinity, using the residual of energy balance method with a combination of eddy covariance and surface renewal equipment. Tree canopy cover, light interception, and plant water status across the orchards were also measured and evaluated. Our preliminary results show that salinity strongly affects the tree water use, resulting in 10-30% less ET for medium to high salt-affected soils. Salinity also showed a strong effect on tree water status and light interception, as suggested by values of the Midday Stem Water Potential (ΨSWP) around 10 to 15-bar lower in salt-affected than in the control orchard, and by the intercepted Photosynthetic Active Radiation (PAR) decreasing from 75% in the control orchard to 25% in the severely salt affected grounds. The crop coefficient values we observed in this study are lower than those commonly used for irrigation scheduling in the SJV, suggesting that pistachio growers could better tailor irrigation management to the actual site-specific orchard conditions (e.g. canopy features and soil-water salinity) if they are provided updated information. Improved irrigation practices could likely lead to significant water savings and thus improve the resource-efficiency and competitiveness of pistachio production in the SJV. Keywords: Pistacia vera L., salinity, stem water potential, surface renewal, canopy cover.

  6. A Note on the Effect of Wind Waves on Vertical Mixing in Franks Tract, Sacramento–San Joaquin Delta, California

    Directory of Open Access Journals (Sweden)

    Nicole L. Jones

    2008-06-01

    Full Text Available A one-dimensional numerical model that simulates the effects of whitecapping waves was used to investigate the importance of whitecapping waves to vertical mixing at a 3-meter-deep site in Franks Tract in the Sacramento-San Joaquin Delta over an 11-day period. Locally-generated waves of mean period approximately 2 s were generated under strong wind conditions; significant wave heights ranged from 0 to 0.3 m. A surface turbulent kinetic energy flux was used to model whitecapping waves during periods when wind speeds > 5 m s-1 (62% of observations. The surface was modeled as a wind stress log-layer for the remaining 38% of the observations. The model results demonstrated that under moderate wind conditions (5–8 m s-1 at 10 m above water level, and hence moderate wave heights, whitecapping waves provided the dominant source of turbulent kinetic energy to only the top 10% of the water column. Under stronger wind (> 8 m s-1, and hence larger wave conditions, whitecapping waves provided the dominant source of turbulent kinetic energy over a larger portion of the water column; however, this region extended to the bottom half of the water column for only 7% of the observation period. The model results indicated that phytoplankton concentrations close to the bed were unlikely to be affected by the whitecapping of waves, and that the formation of concentration boundary layers due to benthic grazing was unlikely to be disrupted by whitecapping waves. Furthermore, vertical mixing of suspended sediment was unlikely to be affected by whitecapping waves under the conditions experienced during the 11-day experiment. Instead, the bed stress provided by tidal currents was the dominant source of turbulent kinetic energy over the bottom half of the water column for the majority of the 11-day period.

  7. Distribution and Habitat Associations of California Black Rail (Laterallus jamaicensis cortuniculus in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Danika C. Tsao

    2015-12-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss4art4Past studies documenting the distribution and status of state “Threatened" California black rail (Laterallus jamaicensis coturniculus; hereafter black rail have largely omitted the Sacramento—San Joaquin Delta (hereafter Delta. During March to May of 2009–2011, we conducted call–playback surveys to assess the status of the species within a wide range of wetland habitats of the central Delta region. We detected black rails at 21 of 107 discrete wetland sites, primarily on in-channel islands with dense cover. To better understand the habitat and land cover characteristics, we developed a model of habitat suitability from these occurrence data and a fine-scale vegetation and land use dataset using MaxEnt. We also evaluated differences in the size of wetlands at sites where black rails were detected versus where they were not. Through surveys and quantitative modeling, we found black rail presence differed from other regions within California and Arizona, in that it was positively associated with tall (1 to 5 m emergent vegetation interspersed with riparian shrubs. Specific plants correlated with black rail presence included emergent wetland (Bolboschoenus acutus, B. californicus, B. acutus, Typha angustifolia, T. latifolia, Phragmites australis and riparian (Salix exigua, S. lasiolepis, Rosa californica, Rubus discolor, Cornus sericea species. Median patch size was significantly larger and perimeter-to-area ratios were significantly lower at wetland sites where black rails were found. These results provide a preliminary characterization of black rail habitat in the Delta region and highlight the need for better understanding of this listed species’ population size and habitat use in the region, in light of anticipated climate change effects and proposed large-scale restoration in the Delta.

  8. 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; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; hide

    2015-01-01

    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.

  9. Resource intensification and osteoarthritis patterns: changes in activity in the prehistoric Sacramento-San Joaquin Delta region.

    Science.gov (United States)

    Cheverko, Colleen M; Bartelink, Eric J

    2017-10-01

    Ethnohistoric accounts and archaeological research from Central California document a shift from the use of lower-cost, high-ranked resources (e.g., large game) toward the greater use of higher-cost, low-ranked resources (e.g., acorns and small seeds) during the Late Holocene (4500-200 BP). The subsistence transition from higher consumption of large game toward an increased reliance on acorns was likely associated with increases in levels of logistical mobility and physical activity. This study predicts that mobility and overall workload patterns changed during this transition to accommodate new food procurement strategies and incorporate new dietary resources during the Late Holocene in Central California. Osteoarthritis prevalence was scored in the shoulder, elbow, hip, and knee of adult individuals (n = 256) from seven archaeological sites in the Sacramento-San Joaquin Delta region. Comparisons were made between osteoarthritis prevalence, sex, age-at-death, and time period using ANCOVAs. The results of this study indicate significant increases in osteoarthritis prevalence in the hip of adult males and females during the Late Period (1200-200 BP), even after correcting for the cumulative effects of age. No differences were observed between the sexes or between time periods for the shoulder, elbow, and knee joints. The temporal increase in hip osteoarthritis supports the hypothesis that there was an increasing need for greater logistical mobility over time to procure key resources away from the village sites. Additionally, the lack of sex differences in osteoarthritis prevalence may suggest that females and males likely performed similar levels of activity during these periods. © 2017 Wiley Periodicals, Inc.

  10. Evaluation of the potential for artificial ground-water recharge in eastern San Joaquin County, California; Phase 3

    Science.gov (United States)

    Hamlin, S.N.

    1987-01-01

    Infiltration tests were used to evaluate the potential of basin spreading surface water as a means of artificially recharging the aquifer system in eastern San Joaquin County, California. Two infiltration sites near Lockeford and Linden were selected on the basis of information collected during the first two phases of the study. Data from the infiltration tests indicate that the two sites are acceptable for recharge by the basin-spreading method. Infiltration rates ranged between 6.7 and 10.5 ft/day near Lockeford and between 2.6 and 11.2 ft/day near Linden. Interpretation of these data is limited by lack of information on the response of the saturated zone during testing and by the inherent difficulty in extrapolating the results of small-scale tests to larger long-term operations. Lithology is a major factor that controls infiltration rates at the test sites. The unsaturated zone is characterized by heterogeneous layers of coarse- and fine- grained materials. Clay layers of low hydraulic conductivity commonly form discontinuous lenses that may cause a transient perched water table to develop during recharge. Water level measurements from wells screened in the unsaturated zone indicate that the perched water table could reach the land surface after 2 and 5 months of recharge near Lockeford and Linden, respectively. These figures probably represent the minimum time necessary for saturation of the land. Another major factor that affects infiltration rates is the quality of the recharge water, particularly the suspended sediment content. The clogging action of suspended sediment may be minimized by: (1) pretreatment of recharge water in a settling pond, (2) adherence to a routine program of monitoring and maintenance, and (3) proper design of the recharge facility. Other factors that affect infiltration rates include basin excavation technique, basin shape, and maintenance procedures. Efficient operation of the recharge facility requires careful attention to the

  11. Determining Water Quality Trends in the Sacramento-San Joaquin Delta Watershed in the Face of Climate Change

    Science.gov (United States)

    Kynett, K.; Azimi-Gaylon, S.; Doidic, C.

    2014-12-01

    The Sacramento-San Joaquin Delta and Suisun Marsh (Delta) is the largest estuary on the West Coast of the Americas and is a resource of local, State, and national significance. The Delta is simultaneously the most critical component of California's water supply, a primary focus of the state's ecological conservation measures, and a vital resource deeply imperiled by degraded water quality. Delta waterbodies are identified as impaired by salinity, excess nutrients, low dissolved oxygen, pathogens, pesticides, heavy metals, and other contaminants. Climate change is expected to exacerbate the impacts of existing stressors in the Delta and magnify the challenges of managing this natural resource. A clear understanding of the current state of the watershed is needed to better inform scientists, decision makers, and the public about potential impacts from climate change. The Delta Watershed Initiative Network (Delta WIN) leverages the ecological benefits of healthy watersheds, and enhances, expands and creates opportunities for greater watershed health by coordinating with agencies, established programs, and local organizations. At this critical junction, Delta WIN is coordinating data integration and analysis to develop better understanding of the existing and emerging water quality concerns. As first steps, Delta WIN is integrating existing water quality data, analyzing trends, and monitoring to fill data gaps and to evaluate indicators of climate change impacts. Available data will be used for trend analysis; Delta WIN will continue to monitor where data is incomplete and new questions arise. Understanding how climate change conditions may affect water quality will be used to inform efforts to build resilience and maintain water quality levels which sustain aquatic life and human needs. Assessments of historical and new data will aid in recognition of potential climate change impacts and in initiating implementation of best management practices in collaboration with

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

    International Nuclear Information System (INIS)

    Andreani-Aksoyoglu, S.; Keller, J.; Prevot, A.S.H.; Chenghsuan Lu; Chang, J.S.

    2001-01-01

    The threshold values of indicator species and ratios delineating the transition between NO x 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 NO x and VOC sensitive regimes. Possible definitions for the distinction of NO x and VOC sensitive ozone production regimes are given. The dependence of the threshold values for indicators and indicator ratios such as NO y , O 3 /NO z , HCHO/NO y , and H 2 O 2 /HNO 3 on the definition of NO x 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. O 3 /NO z and HCHO/NO y indicators are predicted to be unsatisfactory to separate the NO x and VOC sensitive regimes. Although NO y and H 2 O 2 /HNO 3 provide a good separation of the two regimes, threshold values are affected by changes in the environmental conditions studied in this work. (author)

  13. Mapping Evapotranspiration in the Sacramento San Joaquin Delta using simulated ECOSTRESS Thermal Data: Validation and Inter-comparison

    Science.gov (United States)

    Wong, A.; Jin, Y.; He, R.; Hulley, G.; Fisher, J.; Lee, C. M.; Rivera, G.; Hook, S. J.; Medellin-Azuara, J.; Kent, E. R.; Paw U, K. T.; Gao, F.; Lund, J. R.

    2017-12-01

    Irrigation accounts for 80% of human freshwater consumption, and most of it return to the atmosphere through evapotranspiration (ET). In California, where our water resources are limited and heavily utilized, the need for a cost-effective, timely, and consistent spatial estimate of crop ET, from the farm to watershed level, is becoming increasingly important. The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS), to be launched in mid-2018, will provide the most detailed and accurate temperature measurements ever acquired from space and thus unique opportunities for estimating ET at the farm scale. We simulated the ECOSTRESS thermal data at a 70 m resolution using VIIRS thermal observations and ASTER emissivity data in the Sacramento-San Joaquin Delta region for the 2016 water year. Three remote sensing based ET methods were then applied to estimate ET using simulated ECOSTRESS data and optical data from Landsat and VIIRS, including Priestley-Taylor approaches developed by the Jet Propulsion Laboratory (PT-JPL) and by UC Davis (PT-UCD), and the Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) model. We compared these three sets of ET estimates with field measurements at sixteen sites over five crop types (Alfalfa, Corn, Pasture, Tomato, and Beardless Wheat). Good agreement was found between satellite-based estimates and field measurements. Our results demonstrate that thermal data from the upcoming ECOSTRESS mission will reduce the uncertainty in ET estimates. A continuous monitoring of the dynamics and spatial heterogeneity of consumptive water use at a field scale will help prepare and inform to adaptively manage water, canopy, and planting density to maximize yield with least amount of water.

  14. Groundwater quality in the shallow aquifers of the Tulare, Kaweah, and Tule Groundwater Basins and adjacent highlands areas, Southern San Joaquin Valley, California

    Science.gov (United States)

    Fram, Miranda S.

    2017-01-18

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The shallow aquifers of the Tulare, Kaweah, and Tule groundwater basins and adjacent highlands areas of the southern San Joaquin Valley constitute one of the study units being evaluated.

  15. Sensitivity of agricultural runoff loads to rising levels of CO{sub 2} and climate change in the San Joaquin Valley watershed of California

    Energy Technology Data Exchange (ETDEWEB)

    Ficklin, Darren L.; Luo Yuzhou; Luedeling, Eike; Gatzke, Sarah E. [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Zhang Minghua, E-mail: mhzhang@ucdavis.ed [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States)

    2010-01-15

    The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on sediment, nitrate, phosphorus and pesticide (diazinon and chlorpyrifos) runoff in the San Joaquin watershed in California. This study used modeling techniques that include variations of CO{sub 2}, temperature, and precipitation to quantify these responses. Precipitation had a greater impact on agricultural runoff compared to changes in either CO{sub 2} concentration or temperature. Increase of precipitation by +-10% and +-20% generally changed agricultural runoff proportionally. Solely increasing CO{sub 2} concentration resulted in an increase in nitrate, phosphorus, and chlorpyrifos yield by 4.2, 7.8, and 6.4%, respectively, and a decrease in sediment and diazinon yield by 6.3 and 5.3%, respectively, in comparison to the present-day reference scenario. Only increasing temperature reduced yields of all agricultural runoff components. The results suggest that agricultural runoff in the San Joaquin watershed is sensitive to precipitation, temperature, and CO{sub 2} concentration changes. - Agricultural runoff is significantly affected by changes in precipitation, temperature, and atmospheric CO{sub 2} concentration.

  16. Sensitivity of agricultural runoff loads to rising levels of CO2 and climate change in the San Joaquin Valley watershed of California

    International Nuclear Information System (INIS)

    Ficklin, Darren L.; Luo Yuzhou; Luedeling, Eike; Gatzke, Sarah E.; Zhang Minghua

    2010-01-01

    The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on sediment, nitrate, phosphorus and pesticide (diazinon and chlorpyrifos) runoff in the San Joaquin watershed in California. This study used modeling techniques that include variations of CO 2 , temperature, and precipitation to quantify these responses. Precipitation had a greater impact on agricultural runoff compared to changes in either CO 2 concentration or temperature. Increase of precipitation by ±10% and ±20% generally changed agricultural runoff proportionally. Solely increasing CO 2 concentration resulted in an increase in nitrate, phosphorus, and chlorpyrifos yield by 4.2, 7.8, and 6.4%, respectively, and a decrease in sediment and diazinon yield by 6.3 and 5.3%, respectively, in comparison to the present-day reference scenario. Only increasing temperature reduced yields of all agricultural runoff components. The results suggest that agricultural runoff in the San Joaquin watershed is sensitive to precipitation, temperature, and CO 2 concentration changes. - Agricultural runoff is significantly affected by changes in precipitation, temperature, and atmospheric CO 2 concentration.

  17. Modeling tidal freshwater marsh sustainability in the Sacramento-San Joaquin Delta under a broad suite of potential future scenarios

    Science.gov (United States)

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    In this paper, we report on the adaptation and application of a one-dimensional marsh surface elevation model, the Wetland Accretion Rate Model of Ecosystem Resilience (WARMER), to explore the conditions that lead to sustainable tidal freshwater marshes in the Sacramento–San Joaquin Delta. We defined marsh accretion parameters to encapsulate the range of observed values over historic and modern time-scales based on measurements from four marshes in high and low energy fluvial environments as well as possible future trends in sediment supply and mean sea level. A sensitivity analysis of 450 simulations was conducted encompassing a range of eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. porosity values, initial elevations, organic and inorganic matter accumulation rates, and sea-level rise rates. For the range of inputs considered, the magnitude of SLR over the next century was the primary driver of marsh surface elevation change. Sediment supply was the secondary control. More than 84% of the scenarios resulted in sustainable marshes with 88 cm of SLR by 2100, but only 32% and 11% of the scenarios resulted in surviving marshes when SLR was increased to 133 cm and 179 cm, respectively. Marshes situated in high-energy zones were marginally more resilient than those in low-energy zones because of their higher inorganic sediment supply. Overall, the results from this modeling exercise suggest that marshes at the upstream reaches of the Delta—where SLR may be attenuated—and high energy marshes along major channels with high inorganic sediment accumulation rates will be more resilient to global SLR in excess of 88 cm over the next century than their downstream and low-energy counterparts. However, considerable uncertainties exist in the projected rates of sea-level rise and sediment avail-ability. In addition, more research is needed to constrain future

  18. Greenhouse gas emissions and carbon sequestration potential in restored freshwater marshes in the Sacramento San-Joaquin Delta, California

    Science.gov (United States)

    Knox, S. H.; Sturtevant, C. S.; Oikawa, P. Y.; Matthes, J. H.; Dronova, I.; Anderson, F. E.; Verfaillie, J. G.; Baldocchi, D. D.

    2015-12-01

    Wetlands can be effective carbon sinks due to limited decomposition rates in anaerobic soil. As such there is a growing interest in the use of restored wetlands as biological carbon sequestration projects for greenhouse gas (GHG) emission reduction programs. However, using wetlands to offset emissions requires accurate accounting of both carbon dioxide (CO2) and methane (CH4) exchange since wetlands are also sources of CH4. To date few studies have quantified CO2 and CH4 exchange from restored wetlands or assessed how these fluxes vary during ecosystem development. In this study, we report on multiple years of eddy covariance measurements of CO2 and CH4 fluxes from two restored freshwater marshes of differing ages (one restored in 1997 and the other in 2010) in the Sacramento-San Joaquin Delta, CA. Measurements at the younger restored wetland started in October 2010 and began in April 2011 at the older site. The younger restored wetland showed considerable year-to-year variability in the first 4 years following restoration, with CO2 uptake ranging from 12 to 420 g C-CO2 m-2 yr-1. Net CO2 uptake at the older wetland was overall greater than at the younger site, ranging from 292 to 585 g C-CO2 m-2 yr-1. Methane emissions were on average higher at the younger wetland (46 g C-CH4 m-2 yr-1) relative to the older one (33 g C-CH4 m-2 yr-1). In terms of the GHG budgets (assuming a global warming potential of 34), the younger wetland was consistently a GHG source, emitting on average 1439 g CO2 eq m-2 yr-1, while the older wetland was a GHG sink in two of the years of measurement (sequestering 651 and 780 g CO2 eq m-2 yr-1 in 2012 and 2013, respectively) and a source of 750 g CO2 eq m-2 yr-1 in 2014. This study highlights how dynamic CO2 and CH4 fluxes are in the first years following wetland restoration and suggests that restored wetlands have the potential to act as GHG sinks but this may depend on time since restoration.

  19. Implications for sustainability of a changing agricultural mosaic in the Sacramento-San Joaquin Delta, California, USA

    Science.gov (United States)

    Lucero, C. E.; Deverel, S. J.; Jacobs, P.; Kelsey, R.

    2015-12-01

    Transformed from the largest wetland system on the west coast of the United States to agriculture, the Sacramento-San Joaquin Delta is an extreme teaching example of anthropogenic threats to sustainability. For over 6,000 years, over 280,000 ha of intertidal freshwater marsh accreted due to seal level rise and sediment deposition. Farming of organic soils since 1850 resulted in land subsidence caused primarily by oxidation. Over 2 billion cubic meters of soil were lost resulting in elevations on Delta islands ranging from -1 to -8 m and increased risk of levee failures and water supply disruption. Alteration of water flows and habitat caused dramatic declines in aquatic species. A cycle in which oxidation of organic soils leads to deepening of drainage ditches to maintain an aerated root zone which in turn results in sustained oxidation and subsidence is perpetuated by the momentum of the status quo despite evidence that agricultural practices are increasingly unsustainable. Flooding of the soils breaks the oxidation/subsidence cycle. We assessed alternate land uses and the carbon market as a potential impetus for change. Using the peer-reviewed and locally calibrated SUBCALC model, we estimated net global warming potential for a range of scenarios for a representative island, from status quo to incorporating significant proportions of subsidence-mitigating land use. We analyzed economic implications by determining profit losses or gains when a simulated GHG offset market is available for wetlands using a regional agricultural production and economic optimization model, We estimated baseline GHG emissions at about 60,000 tons CO2-e per year. In contrast, modeled implementation of rice and wetlands resulted in substantial emissions reductions to the island being a net GHG sink. Subsidence would be arrested or reversed where these land uses are implemented. Results of economic modeling reveal that conversion to wetlands can have significant negative farm financial

  20. Civilizing the Conversation? Using Surveys to Inform Water Management and Science in the Sacramento-San Joaquin Delta

    Science.gov (United States)

    Hanak, E.; Phillips Chappelle, C.

    2013-12-01

    Improving ecosystem outcomes in California's Sacramento-San Joaquin Delta is a complex, high-stakes water resource management challenge. The Delta is a major hub for water supply conveyance and a valued ecological resource. Yet long-term declines in native fish populations have resulted in severe legal constraints on water exports and fueled growing public debates about the roles and responsibilities of flow modification and other sources of ecosystem stress. Meanwhile, scientific uncertainty, and the inability of the scientific community to effectively communicate what *is* known, has frustrated policymakers and encouraged 'combat science' - the commissioning and use of competing scientific opinions in the courtroom. This paper summarizes results from a study designed to inform the policy process through the use of confidential surveys of scientific researchers (those publishing in peer-reviewed journals, n=122) and engaged stakeholders and policymakers (n=240). The surveys, conducted in mid-2012, sought respondents' views on the sources of ecosystem stress and priority ecosystem management actions. The scientist survey is an example of the growing use of expert elicitation to address gaps in the scientific literature, particularly where there is uncertainty about priorities for decisionmaking (e.g., Cvitanovic et al. 2013, J. of Env. Mgmt; McDaniels et al. 2012, Risk Analysis). The stakeholder survey is a useful complement, enabling the identification of areas of consensus and divergence among stakeholder groups and between these groups and scientific experts. The results suggest such surveys are a promising tool for addressing complex water management problems. We found surprisingly high agreement among scientists on the relative roles of stressors and the most promising management actions; they emphasized restoring more natural processes through habitat and flow actions within the watershed, consistent with 'reconciliation ecology' approaches (Rosenzweig 2003

  1. Riverine Nutrient Trends in the Sacramento and San Joaquin Basins, California: A Comparison to State and Regional Water Quality Policies

    Directory of Open Access Journals (Sweden)

    Brandon Schlegel

    2015-12-01

    Full Text Available doi: http://dx.doi.org/1015447/sfews.2015v13iss4art2Non-point source (NPS contaminant control strategies were initiated in California in the late 1980s under the authority of the State Porter–Cologne Act and eventually for the development of total maximum daily load (TMDL plans, under the federal Clean Water Act. Most of the NPS TMDLs developed for California’s Central Valley (CV region were related to pesticides, but not nutrients. Efforts to reduce pesticide loads and concentrations began in earnest around 1990. The NPS control strategies either encouraged or mandated the use of management practices (MPs. Although TMDLs were largely developed for pesticides, the resultant MPs might have affected the runoff of other potential contaminants (such as nutrients. This study evaluates the effect of agricultural NPS control strategies implemented in California’s CV before and between 1990 and 2013, on nutrients, by comparing trends in surface-water concentrations and loads. In general, use of MPs was encouraged during a “voluntary” period (1990 to 2004 and mandated during an “enforcement” period (2004 to 2013. Nutrient concentrations, loads, and trends were estimated by using a recently developed Weighted Regressions on Time, Discharge, and Season (WRTDS model. Sufficient total phosphorus (TP, total nitrogen (TN, and nitrate (NO3 data were available to compare the voluntary and enforcement periods for twelve sites within the lower Sacramento and San Joaquin basins. Ammonia concentrations and fluxes were evaluated at a subset of these sites. For six of these sites, flow-normalized mean annual concentrations of TP or NO3 decreased at a faster rate during the enforcement period than during the voluntary period. Concentration changes during similar years and ranges of flow conditions suggest that MPs designed for pesticides may also have reduced nutrient loads. Results show that enforceable NPS policies, and accelerated MP implementation

  2. Sensitivity and Uncertainty Analysis for Streamflow Prediction Using Different Objective Functions and Optimization Algorithms: San Joaquin California

    Science.gov (United States)

    Paul, M.; Negahban-Azar, M.

    2017-12-01

    The hydrologic models usually need to be calibrated against observed streamflow at the outlet of a particular drainage area through a careful model calibration. However, a large number of parameters are required to fit in the model due to their unavailability of the field measurement. Therefore, it is difficult to calibrate the model for a large number of potential uncertain model parameters. This even becomes more challenging if the model is for a large watershed with multiple land uses and various geophysical characteristics. Sensitivity analysis (SA) can be used as a tool to identify most sensitive model parameters which affect the calibrated model performance. There are many different calibration and uncertainty analysis algorithms which can be performed with different objective functions. By incorporating sensitive parameters in streamflow simulation, effects of the suitable algorithm in improving model performance can be demonstrated by the Soil and Water Assessment Tool (SWAT) modeling. In this study, the SWAT was applied in the San Joaquin Watershed in California covering 19704 km2 to calibrate the daily streamflow. Recently, sever water stress escalating due to intensified climate variability, prolonged drought and depleting groundwater for agricultural irrigation in this watershed. Therefore it is important to perform a proper uncertainty analysis given the uncertainties inherent in hydrologic modeling to predict the spatial and temporal variation of the hydrologic process to evaluate the impacts of different hydrologic variables. The purpose of this study was to evaluate the sensitivity and uncertainty of the calibrated parameters for predicting streamflow. To evaluate the sensitivity of the calibrated parameters three different optimization algorithms (Sequential Uncertainty Fitting- SUFI-2, Generalized Likelihood Uncertainty Estimation- GLUE and Parameter Solution- ParaSol) were used with four different objective functions (coefficient of determination

  3. 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

  4. Agricultural Chemical Concentrations and Loads in Rivers Draining the Central Valley, California, to the San Francisco Bay-Delta Estuary: Before and During an Extended Drought

    Science.gov (United States)

    Domagalski, J. L.

    2016-12-01

    Drought or near drought conditions have occurred in California since 2012. Although some parts of the State received near normal precipitation in water year 2016, other locations were still below average. Extended drought can impact aquatic organisms in a variety of ways because of decreased flows and elevated water temperature. However, lower precipitation and availability of irrigation water may limit subsequent runoff, resulting in reduced concentrations and loads of certain environmental toxicants, such as pesticides and ammonia, thereby limiting their toxic effects. In this study, funded by the U.S. Geological Survey National Water Quality Program, the occurrence of 227 pesticides and degradation products, and nutrients was assessed before and during this current drought in the two largest rivers draining to the San Francisco Bay: the Sacramento and San Joaquin Rivers. The watersheds of both rivers include substantial agricultural and urban land use. Herbicides, insecticides, fungicides, and ammonia were detected throughout the study (2010 to 2016) and models of daily concentration using the seasonal wave model (rloadest) were formulated to assess the amount of time that concentrations may have exceeded benchmark levels known to be toxic to aquatic organisms. Frequently detected pesticides included the fungicide azoxystrobin, herbicides or their degradation products such as diuron, glyphosate, and metolachlor, and insecticides such as imidacloprid. Compounds that are transported primarily by surface runoff generally showed decreasing concentrations as the drought progressed, especially in the San Joaquin River. Compounds mainly transported by groundwater, as indicated by seasonal concentration profiles, had more stable concentrations in the rivers. Mass loads to the Bay all decreased, as expected, because of the lower river discharge. When compared to aquatic-life benchmarks, modeled concentrations indicated that individual compounds were not contributing to

  5. Ground-Water Quality Data in the Southeast San Joaquin Valley, 2005-2006 - Results from the California GAMA Program

    Science.gov (United States)

    Burton, Carmen A.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 3,800 square-mile Southeast San Joaquin Valley study unit (SESJ) was investigated from October 2005 through February 2006 as part of the Priority Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The SESJ study was designed to provide a spatially unbiased assessment of raw ground-water quality within SESJ, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 99 wells in Fresno, Tulare, and Kings Counties, 83 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and 16 of which were sampled to evaluate changes in water chemistry along ground-water flow paths or across alluvial fans (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine, and 1,2,3-trichloropropane), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, nitrogen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected at approximately 10 percent of the wells, and the results

  6. Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California

    Science.gov (United States)

    Bergamaschi, Brian A.; Downing, Bryan D.; Kraus, Tamara E.C.; Pellerin, Brian A.

    2017-07-11

    Executive SummaryThis report is the third in a series of three reports that provide information about how high-frequency (HF) nutrient monitoring may be used to assess nutrient inputs and dynamics in the Sacramento–San Joaquin Delta, California (Delta). The purpose of this report is to provide the background, principles, and considerations for designing an HF nutrient-monitoring network for the Delta to address high-priority, nutrient-management questions. The report starts with discussion of the high-priority management questions to be addressed, continues through discussion of the questions and considerations that place demands and constraints on network design, discusses the principles applicable to network design, and concludes with the presentation of three example nutrient-monitoring network designs for the Delta. For three example network designs, we assess how they would address high-priority questions that have been identified by the Delta Regional Monitoring Program (Delta Regional Monitoring Program Technical Advisory Committee, 2015).This report, along with the other two reports of this series (Kraus and others, 2017; Downing and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta. The first report in the series (Kraus and others, 2017) provides an introduction to the reasons for and fundamental concepts behind using HF monitoring measurements, including a brief summary of nutrient status and trends in the Delta and an extensive literature review showing how and where other research and monitoring programs have used HF monitoring to improve our understanding of nutrient cycling. The report covers the various technologies available for HF nutrient monitoring and presents the different ways HF monitoring instrumentation may be used for both fixed station and spatial

  7. Groundwater-quality data in the Western San Joaquin Valley study unit, 2010 - Results from the California GAMA Program

    Science.gov (United States)

    Mathany, Timothy M.; Landon, Matthew K.; Shelton, Jennifer L.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the approximately 2,170-square-mile Western San Joaquin Valley (WSJV) study unit was investigated by the U.S. Geological Survey (USGS) from March to July 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The WSJV study unit was the twenty-ninth study unit to be sampled as part of the GAMA-PBP. The GAMA Western San Joaquin Valley study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system, and to facilitate statistically consistent comparisons of untreated groundwater quality throughout California. The primary aquifer system is defined as parts of aquifers corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the WSJV study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the WSJV study unit, groundwater samples were collected from 58 wells in 2 study areas (Delta-Mendota subbasin and Westside subbasin) in Stanislaus, Merced, Madera, Fresno, and Kings Counties. Thirty-nine of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 19 wells were selected to aid in the understanding of aquifer-system flow and related groundwater-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], low-level fumigants, and pesticides and pesticide degradates

  8. 33 CFR 110.224 - San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin...

    Science.gov (United States)

    2010-07-01

    ... area shown on a Government chart. (5) No vessel may moor, anchor, or tie up to any pier, wharf, or... supervision may go alongside or in any manner moor to any Government-owned vessel, mooring buoy, or pontoon...); and the side boundaries of which are parallel tangents joining the semicircles. A forbidden anchorage...

  9. Ozone Laminae and Their Entrainment Into a Valley Boundary Layer, as Observed From a Mountaintop Monitoring Station, Ozonesondes, and Aircraft Over California's San Joaquin Valley

    Science.gov (United States)

    Faloona, I. C.; Conley, S. A.; Caputi, D.; Trousdell, J.; Chiao, S.; Eiserloh, A. J., Jr.; Clark, J.; Iraci, L. T.; Yates, E. L.; Marrero, J. E.; Ryoo, J. M.; McNamara, M. E.

    2016-12-01

    The San Joaquin Valley of California is wide ( 75 km) and long ( 400 km), and is situated under strong atmospheric subsidence due, in part, to the proximity of the midlatitude anticyclone of the Pacific High. The capping effect of this subsidence is especially prominent during the warm season when ground level ozone is a serious air quality concern across the region. While relatively clean marine boundary layer air is primarily funneled into the valley below the strong subsidence inversion at significant gaps in the upwind Coast Range mountains, airflow aloft also spills over these barriers and mixes into the valley from above. Because this transmountain flow occurs under the influence of synoptic subsidence it tends to present discrete, laminar sheets of differing air composition above the valley boundary layer. Meanwhile, although the boundary layers tend to remain shallow due to the prevailing subsidence, orographic and anabatic venting of valley boundary layer air around the basin whips up a complex admixture of regional air masses into a "buffer layer" just above the boundary layer (zi) and below the lower free troposphere. We present scalar data of widely varying lifetimes including ozone, methane, NOx, and thermodynamic observations from upwind and within the San Joaquin Valley to better explain this layering and its subsequent erosion into the valley boundary layer via entrainment. Data collected at a mountaintop monitoring station on Chews Ridge in the Coast Range, by coastal ozonesondes, and aircraft are analyzed to document the dynamic layering processes around the complex terrain surrounding the valley. Particular emphasis will be made on observational methods whereby distal ozone can be distinguished from the regional ozone to better understand the influence of exogenous sources on air quality in the valley.

  10. Lowland riparian herpetofaunas: the San Pedro River in southeastern Arizona

    Science.gov (United States)

    Philip C. Rosen

    2005-01-01

    Previous work has shown that southeastern Arizona has a characteristic, high diversity lowland riparian herpetofauna with 62-68 or more species along major stream corridors, and 46-54 species in shorter reaches within single biomes, based on intensive fieldwork and museum record surveys. The San Pedro River supports this characteristic herpetofauna, at least some of...

  11. 76 FR 70480 - Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National...

    Science.gov (United States)

    2011-11-14

    ... River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National Wildlife...), intend to prepare an environmental impact statement (EIS) for the proposed Otay River Estuary Restoration... any one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  12. A compilation of U.S. Geological Survey pesticide concentration data for water and sediment in the Sacramento–San Joaquin Delta region: 1990–2010

    Science.gov (United States)

    Orlando, James L.

    2013-01-01

    Beginning around 2000, abundance indices of four pelagic fishes (delta smelt, striped bass, longfin smelt, and threadfin shad) within the San Francisco Bay and Sacramento–San Joaquin Delta began to decline sharply (Sommer and others, 2007). These declines collectively became known as the pelagic organism decline (POD). No single cause has been linked to this decline, and current theories suggest that combinations of multiple stressors are likely to blame. Contaminants (including current-use pesticides) are one potential stressor being investigated for its role in the POD (Anderson, 2007). Pesticide concentration data collected by the U.S. Geological Survey (USGS) at multiple sites in the delta region over the past two decades are critical to understanding the potential effects of current-use pesticides on species of concern as well as the overall health of the delta ecosystem. In April 2010, a compilation of contaminant data for the delta region was published by the State Water Resources Control Board (Johnson and others, 2010). Pesticide occurrence was the major focus of this report, which concluded that “there was insufficient high quality data available to make conclusions about the potential role of specific contaminants in the POD.” The report cited multiple sources; however, data collected by the USGS were not included in the publication even though these data met all criteria listed for inclusion in the report. What follows is a summary of publicly available USGS data for pesticide concentrations in surface water and sediments within the Sacramento–San Joaquin Delta region from the years 1990 through 2010. Data were retrieved though the USGS National Water Information System (NWIS) database, a publicly available online-data repository (U.S. Geological Survey, 1998), and from published USGS reports (also available online at http://pubs.er.usgs.gov/). The majority of the data were collected in support of two long term USGS monitoring programs

  13. Serologic survey for disease in endangered San Joaquin kit fox, Vulpes macrotis mutica, inhabiting the Elk Hills Naval Petroleum Reserve, Kern County, California

    Energy Technology Data Exchange (ETDEWEB)

    McCue, P.M.; O' Farrell, T.P.

    1986-07-01

    Serum from endangered San Joaquin kit foxes, Vulpes macrotis mutica, and sympatric wildlife inhabiting the Elk Hills Petroleum Reserve, Kern County, and Elkhorn Plain, San Luis Obispo County, California, was collected in 1981 to 1982 and 1984, and tested for antibodies against 10 infectious disease pathogens. Proportions of kit fox sera containing antibodies against diseases were: canine parvovirus, 100% in 1981 to 1982 and 67% in 1984; infectious canine hepatitis, 6% in 1981 to 1982 and 21% in 1984; canine distemper, 0 in 1981 to 1982 and 14% in 1984; tularemia, 8% in 1981 to 1982 and 31% in 1984; Brucella abortus, 8% in 1981 to 1982 and 3% in 1984; Brucella canis, 14% in 1981 to 1982 and 0 in 1984; toxoplasmosis, 6% in 1981 to 1982; coccidioidomycosis, 3% in 1981 to 1982; and plague and leptospirosis, 0 in 1981 to 1982. High population density, overlapping home ranges, ability to disperse great distances, and infestation by ectoparasites were cited as possible factors in the transmission and maintenance of these diseases in kit fox populations.

  14. San Jacinto River oil spill: wetland bioremediation project

    International Nuclear Information System (INIS)

    Mills, M.A.; Bonner, J.S.

    1996-01-01

    Gasoline, diesel and unrefined Arabian light crude oil were accidentally released into the San Jacinto River after a series of pipelines ruptured. Natural removal processes (volatilization, dissolution, weathering), fire, and the spill clean-up effort, removed approximately 95% of the petroleum. The area where residual oil was found was an estuarine wetland on the lower San Jacinto River. Samples were collected from 21 study areas and an evaluation of the varying levels of bioremediation was conducted. Phase one has been completed and involved the evaluation of the natural recovery of oil from the spill. Phase two was still in progress and involved the addition of inorganic nutrients and the alternate electron acceptor to enhance the biodegradation of the petroleum. Results showed that biodegradation was responsible for much of the reduction of certain components in petroleum within the first 150 days. 12 refs., 8 figs

  15. Status and understanding of groundwater quality in the central-eastside San Joaquin Basin, 2006: California GAMA Priority Basin Project

    Science.gov (United States)

    Landon, Matthew K.; Belitz, Kenneth; Jurgens, Bryant C.; Kulongoski, Justin T.; Johnson, Tyler D.

    2010-01-01

    Groundwater quality in the approximately 1,695-square-mile Central Eastside San Joaquin Basin (Central Eastside) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001, and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The GAMA Central Eastside study unit was designed to provide a spatially unbiased assessment of untreated-groundwater quality, as well as a statistically consistent basis for comparing water quality throughout California. During March through June 2006, samples were collected from 78 wells in Stanislaus and Merced Counties, 58 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 20 of which were sampled to evaluate changes in water chemistry along groundwater-flow paths (understanding wells). Water-quality data from the California Department of Public Health (CDPH) database also were used for the assessment.An assessment of the current status of the groundwater quality included collecting samples from wells for analysis of anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring constituents such as major ions and trace elements. The assessment of status is intended to characterize the quality of untreated-groundwater resources within the primary aquifer system, not the treated drinking water delivered to consumers by water purveyors. The primary aquifer system (hereinafter, primary aquifer) is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the Central Eastside study unit. The quality of groundwater in shallower or

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

    Directory of Open Access Journals (Sweden)

    Stephen R. Kaffka

    2013-09-01

    Full Text Available 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 dactylon (L. Pers. growth, quality, and use by cattle. Simulations based on field measurements and a related container study indicate that although soil chemical composition is affected by irrigation water quality, irrigation timing and frequency can be used to mitigate salt and trace mineral accumulation. Bermuda grass yields of up to 12 Mg dry matter (DM·ha−1 were observed at the field site and predicted by the model. Forage yield and quality supports un-supplemented cattle stocking rates of 1.0 to 1.2 animal units (AU·ha−1. However, a balance must be achieved between stocking rate, desired average daily gain, accumulation of salts in the soil profile, and potential pollution of ground water from drainage and leaching. Using available weather data, crop-specific parameter values and field scale measurements of soil salinity and nitrogen levels, the model can be used by farmers growing forages on saline soils elsewhere, to sustain forage and livestock production under similarly marginal conditions.

  17. Effects of military-authorized activities on the San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    Energy Technology Data Exchange (ETDEWEB)

    Berry, W.H.; Standley, W.G.; O`Farrell, T.P.; Kato, T.T.

    1992-10-01

    The effects of military-authorized activities on San Joaquin kit fox (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site from 1988 to 1991. Military-authorized activities included military training exercises, facilities maintenance, new construction, controlled burning, livestock grazing, and public-access hunting. Positive effects of the military included habitat preservation, preactivity surveys, and natural resources management practices designed to conserve kit foxes and their habitat. Perceived negative effects such as entrapment in dens, shootings during military exercises, and accidental poisoning were not observed. Foxes were observed in areas being used simultaneously by military units. Authorized activities were known to have caused the deaths of three of 52 radiocollared foxes recovered dead: one became entangled in concertina wire, one was believed shot by a hunter, and one was struck by a vehicle. Entanglement in communication wire may have contributed to the death of another radiocollared fox that was killed by a predator. Approximately 10% of kit fox dens encountered showed evidence of vehicle traffic, but denning sites did not appear to be a limiting factor for kit foxes.

  18. 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.

    2014-01-01

    We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997–2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects. PMID:24553680

  19. Ion exchange and trace element surface complexation reactions associated with applied recharge of low-TDS water in the San Joaquin Valley, California

    International Nuclear Information System (INIS)

    McNab, Walt W.; Singleton, Michael J.; Moran, Jean E.; Esser, Bradley K.

    2009-01-01

    Stable isotope data, a dissolved gas tracer study, groundwater age dating, and geochemical modeling were used to identify and characterize the effects of introducing low-TDS recharge water in a shallow aerobic aquifer affected by a managed aquifer recharge project in California's San Joaquin Valley. The data all consistently point to a substantial degree of mixing of recharge water from surface ponds with ambient groundwater in a number of nearby wells screened at depths above 60 m below ground surface. Groundwater age data indicate that the wells near the recharge ponds sample recently recharged water, as delineated by stable O and C isotope data as well as total dissolved solids, in addition to much older groundwater in various mixing proportions. Where the recharge water signature is present, the specific geochemical interactions between the recharge water and the aquifer material appear to include ion exchange reactions (comparative enrichment of affected groundwater with Na and K at the expense of Ca and Mg) and the desorption of oxyanion-forming trace elements (As, V, and Mo), possibly in response to the elevated pH of the recharge water

  20. Tamarisk and river restoration along the San Pedro and Gila Rivers

    Science.gov (United States)

    Juliet Stromberg; Sharon Lite; Charles Paradzick

    2005-01-01

    The abundance of tamarisk (Tamarix ramosissima and related species) along the San Pedro and Gila River flood plains varies with differences in stream flow regimes. Tamarisk abundance, relative to Fremont cottonwood and Goodding willow, is greater at sites with more intermittent stream flows and deeper and more fluctuating ground-water levels....

  1. 78 FR 6833 - Final Environmental Impact Statement/Environmental Impact Report for the San Joaquin River...

    Science.gov (United States)

    2013-01-31

    ... locations: Bureau of Reclamation, Regional Library, 2800 Cottage Way, Sacramento, CA 95825-1898 California State Library, 914 Capitol Mall, Suite E-29, Sacramento, CA 95814-4802 University of California... California Research Bureau, California State Library, PO Box 942837, Sacramento, CA 94237-0001 Fresno County...

  2. H10895: NOS Hydrographic Survey , San Joaquin River, California, 1999-08-03

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  3. Hydrogeologic reconnaissance of the San Miguel River basin, southwestern Colorado

    Science.gov (United States)

    Ackerman, D.J.; Rush, F.E.

    1984-01-01

    The San Miguel River Basin encompasses 4,130 square kilometers of which about two-thirds is in the southeastern part of the Paradox Basin. The Paradox Basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Evaporite beds of mostly salt are both overlain and underlain by confining beds. Aquifers are present above and below the confining-bed sequence. The principal element of ground-water outflow from the upper aquifer is flow to the San Miguel River and its tributaries; this averages about 90 million cubic meters per year. A water budget for the lower aquifer has only two equal, unestimated elements, subsurface outflow and recharge from precipitation. The aquifers are generally isolated from the evaporite beds by the bounding confining beds; as a result, most ground water has little if any contact with the evaporites. No brines have been sampled and no brine discharges have been identified in the basin. Salt water has been reported for petroleum-exploration wells, but no active salt solution has been identified. (USGS)

  4. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA.

    Science.gov (United States)

    Drexler, Judith Z; Alpers, Charles N; Neymark, Leonid A; Paces, James B; Taylor, Howard E; Fuller, Christopher C

    2016-05-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and (210)Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0μgg(-1)and from 6.9 to 71ngg(-1), respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850CE), when concentrations reached their highest levels (74μgg(-1) Pb, 990ngg(-1) Hg; PbEF=12 and HgEF=28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425CE, it has received Pb and Hg contamination from both global and regional sources. Published by Elsevier B.V.

  5. Polycyclic hydrocarbon biomarkers confirm selective incorporation of petroleum in soil and kangaroo rat liver samples near an oil well blowout site in the western San Joaquin Valley, California

    International Nuclear Information System (INIS)

    Kaplan, I.; Lu, S.T.; Lee, R.P.; Warrick, G.

    1996-01-01

    Following an accidental oil well blow out at an oil field in the western part of the San Joaquin Valley, soil samples and specimens of Heermann's kangaroo rats (Dipodomys heermanni) were collected from two oil-impacted areas and one control area. Fingerprinting by GC-MS and quantitative evaluation of metabolized petroleum hydrocarbons was performed on oil, soil extracts, and rat livers. A liver from a domestically raised rabbit was used as an experimental control. The results show that there is no significant incorporation of PAHs or low molecular weight n-alkanes (C 13 --C 25 ) into the liver tissues. The C 25 --C 35 n-alkane range for all soil samples, kangaroo rat livers, and rabbit liver, is dominated by a high abundance of C 27 , C 29 , C 31 , and C 33 hydrocarbons typical of epicuticular plant waxes. In all liver tissue samples, squalene, the cholesterol precursor, is the dominant hydrocarbon. Although evidence is lacking for metabolism of PAHs and paraffinic petroleum hydrocarbons, very strong evidence is available for incorporation of a set of polycyclic hydrocarbons (biomarkers) belonging to the terpane, sterane, and monoaromatic and triaromatic sterane families, identified by ion monitoring at 191, 217, 253, and 231 m/z, respectively. Because these hydrocarbons are not known to exist in the biosphere, but are only synthesized during oil- and coal-forming processes, their presence in the liver samples constitutes proof for crude oil incorporation into tissues. This conclusion is further substantiated by the selective incorporation of only the 20S enantiomer of C 28 and C 29 steranes and aromatic steranes into the livers, with the exclusion of the 20R enantiomer. The results from the study conclusively demonstrate that polycyclic hydrocarbon biomarkers provide excellent indices for proof of petroleum exposure and metabolism in some terrestrial herbivores

  6. Organic Carbon and Disinfection Byproduct Precursor Loads from a Constructed, Non-Tidal Wetland in California's Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Jacob A. Fleck

    2007-05-01

    Full Text Available Wetland restoration on peat islands in the Sacramento-San Joaquin Delta will change the quality of island drainage waters entering the Delta, a primary source of drinking water in California. Peat island drainage waters contain high concentrations of dissolved and particulate organic carbon (DOC and POC and organic precursors to drinking water disinfection byproducts, such as trihalomethanes (THMs. We quantified the net loads of DOC, POC, and THM-precursors from a constructed subsidence mitigation wetland on Twitchell Island in the Delta to determine the change in drainage water quality that may be caused by conversion of agricultural land on peat islands to permanently flooded, non-tidal wetlands. Creation of permanently flooded wetlands halts oxidative loss of the peat soils and thereby may mitigate the extensive land-surface subsidence of the islands that threatens levee stability in the Delta. Net loads from the wetland were dominated by DOC flushed from the oxidized shallow peat soil layer by seepage flow out of the wetland. The permanently flooded conditions in the overlying wetland resulted in a gradual evolution to anaerobic conditions in the shallow soil layer and a concomitant decrease in the flow could be minimized by reducing the hydraulic gradient between the wetland and the adjacent drainage ditch. Estimates of net loads from the wetland assuming efflux of surface water only were comparable in magnitude to net loads from nearby agricultural fields, but the wetland and agricultural net loads had opposite seasonal variations. Wetland surface water net loads of DOC, POC, and THM-precursors were lower during the winter months when the greatest amounts of water are available for diversion from the Delta to drinking water reservoirs.

  7. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA

    Science.gov (United States)

    Drexler, Judith; Alpers, Charles N.; Neymark, Leonid; Paces, James B.; Taylor, Howard E.; Fuller, Christopher C.

    2016-01-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon, 210Pb, and 137Cs. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 µg g-1and from 6.9 to 71 ng g-1, respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850 CE), when concentrations reached their highest levels (74 µg g-1 Pb, 990 ng g-1 Hg; PbEF = 12 and HgEF = 28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425 CE, it has received Pb and Hg contamination from both global and regional sources.

  8. Results of analyses of fur samples from the San Joaquin Kit Fox and associated soil and water samples from the Naval Petroleum Reserve No. 1, Tupman, California

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II; Rosen, A.E.; Beauchamp, J.J. (Oak Ridge National Lab., TN (United States)); Kato, T.T. (EG and G Energy Measurements, Inc., Tupman, CA (United States))

    1992-12-01

    The purpose of this study was to determine whether analysis of the elemental content of fur from San Joaquin kit foxes (Vulpes macrotis mutica) and of water and soil from kit fox habitats could be used to make inferences concerning the cause of an observed decline in the kit fox population on Naval Petroleum Reserve No. 1 (NPR-1). Fur samples that had been collected previously from NPR-1, another oil field (NPR-2), and two sites with no oil development were subjected to neutron activation analysis. In addition, soil samples were collected from the home ranges of individual foxes from undisturbed portions of major soil types on NPR-1 and from wastewater samples were collected from tanks and sumps and subjected to neutron activation analysis. Most elemental concentrations in fur were highest at Camp Roberts and lowest on the undeveloped portions of NPR-I. Fur concentrations were intermediate on the developed oil fields but were correlated with percent disturbance and with number of wells on NPR-1 and NPR-2. The fact that most elements covaried across the range of sites suggests that some pervasive source such as soil was responsible. However, fur concentrations were not correlated with soft concentrations. The kit foxes on the developed portion of NPR-1 did not have concentrations of elements in fur relative to other sites that would account for the population decline in the early 1980s. The oil-related elements As, Ba, and V were elevated in fox fur from oil fields, but only As was sufficiently elevated to suggest a risk of toxicity in individual foxes. However, arsenic concentrations suggestive of sublethal toxicity were found in only 0.56% of foxes from developed oil fields, too few to account for a population decline.

  9. Chemistry of uranium in evaporation pond sediment in the San Joaquin Valley, California, USA, using x-ray fluorescence and XANES techniques

    International Nuclear Information System (INIS)

    Duff, M.C.; Amrhein, C.; Bertsch, P.M.; Hunter, D.B.

    1997-01-01

    Evaporation ponds in the San Joaquin Valley (SJV), CA, used for the disposal of irrigation drainage waters, contain elevated levels of uranium. The ponds are filled periodically and support algae which upon evaporation become incorporated in the sediments as layers of decaying organic matter. This rich source of organic matter promotes reducing conditions in the sediments. Our research was conducted to characterize oxidation/reduction reactions that affect soluble and sediment U(IV)/U(VI) concentrations in the SJV ponds. Studies were done to (1) determine soluble U(Vl)/U(IV) in waters in contact with a pond sediment subjected to changes in redox status, (2) observe U solid oxidation state as a reducing pond sediment underwent (in vitro) oxidation, and (3) determine U solid oxidation state with respect to depth in pond surface sediment layers. Low pressure ion-exchange chromatography with an eluent of 0.125 M H 2 C 2 O 4 /0.25 M HNO 3 was used for the separation of U(IV) and U(VI) oxidation states in the drainage waters. Soluble U(VI) and U(IV) coexisted in sediment suspensions exposed to changes in redox potential (Eh) (-260 mV to +330 mV), and U(VI) was highly soluble in the oxidized, surface pond sediments. X-ray near edge absorption spectroscopy (XANES) showed that the U solid phases were 25% U(IV) and 75% U(VI) and probably a mixed solid [U 3 O 8(s) ] in highly reducing pond sediments. Sediment U(IV) increased slightly with depth in the surface pond sediment layers suggesting a gradual reduction of U(VI) to U(IV) with time. Under oxidized conditions, this mixed oxidation-state solid was highly soluble. 59 refs., 6 figs., 1 tab

  10. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    Science.gov (United States)

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  11. Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

    Science.gov (United States)

    Bennett, Katrina E.; Bohn, Theodore J.; Solander, Kurt; McDowell, Nathan G.; Xu, Chonggang; Vivoni, Enrique; Middleton, Richard S.

    2018-01-01

    Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash-Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate-disturbance scenarios is at least 6-11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15-21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.

  12. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento–San Joaquin Delta of California, USA

    International Nuclear Information System (INIS)

    Drexler, Judith Z.; Alpers, Charles N.; Neymark, Leonid A.; Paces, James B.; Taylor, Howard E.; Fuller, Christopher C.

    2016-01-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento–San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and "2"1"0Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 μg g"−"1and from 6.9 to 71 ng g"−"1, respectively. For much of the past 6000 + years, the Delta was free from anthropogenic pollution, however, beginning in ~ 1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~ 1850 CE), when concentrations reached their highest levels (74 μg g"−"1 Pb, 990 ng g"−"1 Hg; PbEF = 12 and HgEF = 28). Lead concentrations increased again beginning in the ~ 1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~ 6700-year existence; however, since ~ 1425 CE, it has received Pb and Hg contamination from both global and regional sources. - Highlights: • Micro-tidal peats were used to trace Pb and Hg contamination through the millennia. • Anthropogenic Pb and Hg were first evident in California in ~ 1425 CE. • Pb isotopes suggest early contamination may be from ore smelting in China. • Pb (74 μg g

  13. Agricultural peatland restoration: effects of land-use change on greenhouse gas (CO2 and CH4) fluxes in the Sacramento-San Joaquin Delta.

    Science.gov (United States)

    Knox, Sara Helen; Sturtevant, Cove; Matthes, Jaclyn Hatala; Koteen, Laurie; Verfaillie, Joseph; Baldocchi, Dennis

    2015-02-01

    Agricultural drainage of organic soils has resulted in vast soil subsidence and contributed to increased atmospheric carbon dioxide (CO2) concentrations. The Sacramento-San Joaquin Delta in California was drained over a century ago for agriculture and human settlement and has since experienced subsidence rates that are among the highest in the world. It is recognized that drained agriculture in the Delta is unsustainable in the long-term, and to help reverse subsidence and capture carbon (C) there is an interest in restoring drained agricultural land-use types to flooded conditions. However, flooding may increase methane (CH4) emissions. We conducted a full year of simultaneous eddy covariance measurements at two conventional drained agricultural peatlands (a pasture and a corn field) and three flooded land-use types (a rice paddy and two restored wetlands) to assess the impact of drained to flooded land-use change on CO2 and CH4 fluxes in the Delta. We found that the drained sites were net C and greenhouse gas (GHG) sources, releasing up to 341 g C m(-2) yr(-1) as CO2 and 11.4 g C m(-2) yr(-1) as CH4. Conversely, the restored wetlands were net sinks of atmospheric CO2, sequestering up to 397 g C m(-2) yr(-1). However, they were large sources of CH4, with emissions ranging from 39 to 53 g C m(-2) yr(-1). In terms of the full GHG budget, the restored wetlands could be either GHG sources or sinks. Although the rice paddy was a small atmospheric CO2 sink, when considering harvest and CH4 emissions, it acted as both a C and GHG source. Annual photosynthesis was similar between sites, but flooding at the restored sites inhibited ecosystem respiration, making them net CO2 sinks. This study suggests that converting drained agricultural peat soils to flooded land-use types can help reduce or reverse soil subsidence and reduce GHG emissions. © 2014 John Wiley & Sons Ltd.

  14. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento–San Joaquin Delta of California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Drexler, Judith Z., E-mail: jdrexler@usgs.gov [U.S. Geological Survey, California Water Science Center, 6000 J Street, Placer Hall, Sacramento, CA 95819-6129 (United States); Alpers, Charles N., E-mail: cnalpers@usgs.gov [U.S. Geological Survey, California Water Science Center, 6000 J Street, Placer Hall, Sacramento, CA 95819-6129 (United States); Neymark, Leonid A., E-mail: lneymark@usgs.gov [U.S. Geological Survey, Box 25046, MS963, Denver Federal Center, Denver, CO 80225 (United States); Paces, James B., E-mail: jbpaces@usgs.gov [U.S. Geological Survey, Box 25046, MS963, Denver Federal Center, Denver, CO 80225 (United States); Taylor, Howard E., E-mail: hetaylor@usgs.gov [U.S. Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303 (United States); Fuller, Christopher C., E-mail: ccfuller@usgs.gov [U.S. Geological Survey, 345 Middlefield Road, MS465, Menlo Park, CA 94025 (United States)

    2016-05-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento–San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and {sup 210}Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 μg g{sup −1}and from 6.9 to 71 ng g{sup −1}, respectively. For much of the past 6000 + years, the Delta was free from anthropogenic pollution, however, beginning in ~ 1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~ 1850 CE), when concentrations reached their highest levels (74 μg g{sup −1} Pb, 990 ng g{sup −1} Hg; PbEF = 12 and HgEF = 28). Lead concentrations increased again beginning in the ~ 1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~ 6700-year existence; however, since ~ 1425 CE, it has received Pb and Hg contamination from both global and regional sources. - Highlights: • Micro-tidal peats were used to trace Pb and Hg contamination through the millennia. • Anthropogenic Pb and Hg were first evident in California in ~ 1425 CE. • Pb isotopes suggest early contamination may be from ore smelting in China

  15. Factors affecting marsh vegetation at the Liberty Island Conservation Bank in the Cache Slough region of the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Orlando, James L.; Drexler, Judith Z.

    2017-07-07

    The Liberty Island Conservation Bank (LICB) is a tidal freshwater marsh restored for the purpose of mitigating adverse effects on sensitive fish populations elsewhere in the region. The LICB was completed in 2012 and is in the northern Cache Slough region of the Sacramento–San Joaquin Delta. The wetland vegetation at the LICB is stunted and yellow-green in color (chlorotic) compared to nearby wetlands. A study was done to investigate three potential causes of the stunted and chlorotic vegetation: (1) improper grading of the marsh plain, (2) pesticide contamination from agricultural and urban inputs upstream from the site, (3) nitrogen-deficient soil, or some combination of these. Water samples were collected from channels at five sites, and soil samples were collected from four wetlands, including the LICB, during the summer of 2015. Real-time kinematic global positioning system (RTK-GPS) elevation surveys were completed at the LICB and north Little Holland Tract, a closely situated natural marsh that has similar hydrodynamics as the LICB, but contains healthy marsh vegetation.The results showed no significant differences in carbon or nitrogen content in the surface soils or in pesticides in water among the sites. The elevation survey indicated that the mean elevation of the LICB was about 26 centimeters higher than that of the north Little Holland Tract marsh. Because marsh plain elevation largely determines the hydroperiod of a marsh, these results indicated that the LICB has a hydroperiod that differs from that of neighboring north Little Holland Tract marsh. This difference in hydroperiod contributed to the lower stature and decreased vigor of wetland vegetation at the LICB. Although the LICB cannot be regraded without great expense, it could be possible to reduce the sharp angle of the marsh edge to facilitate deeper and more frequent tidal flooding along the marsh periphery. Establishing optimal elevations for restored wetlands is necessary for obtaining

  16. Re-establishing marshes can return carbon sink functions to a current carbon source in the Sacramento-San Joaquin Delta of California, USA

    Science.gov (United States)

    Miller, Robin L.; Fujii, Roger; Schmidt, Paul E.

    2011-01-01

    The Sacramento-San Joaquin Delta in California was an historic, vast inland freshwater wetland, where organic soils almost 20 meters deep formed over the last several millennia as the land surface elevation of marshes kept pace with sea level rise. A system of levees and pumps were installed in the late 1800s and early 1900s to drain the land for agricultural use. Since then, land surface has subsided more than 7 meters below sea level in some areas as organic soils have been lost to aerobic decomposition. As land surface elevations decrease, costs for levee maintenance and repair increase, as do the risks of flooding. Wetland restoration can be a way to mitigate subsidence by re-creating the environment in which the organic soils developed. A preliminary study of the effect of hydrologic regime on carbon cycling conducted on Twitchell Island during the mid-1990s showed that continuous, shallow flooding allowing for the growth of emergent marsh vegetation re-created a wetland environment where carbon preservation occurred. Under these conditions annual plant biomass carbon inputs were high, and microbial decomposition was reduced. Based on this preliminary study, the U.S. Geological Survey re-established permanently flooded wetlands in fall 1997, with shallow water depths of 25 and 55 centimeters, to investigate the potential to reverse subsidence of delta islands by preserving and accumulating organic substrates over time. Ten years after flooding, elevation gains from organic matter accumulation in areas of emergent marsh vegetation ranged from almost 30 to 60 centimeters, with average annual carbon storage rates approximating 1 kg/m2, while areas without emergent vegetation cover showed no significant change in elevation. Differences in accretion rates within areas of emergent marsh vegetation appeared to result from temporal and spatial variability in hydrologic factors and decomposition rates in the wetlands rather than variability in primary production

  17. Elements of an environmental decision support system for seasonal wetland salt management in a river basin subjected to water quality regulation

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T.

    2009-06-01

    Seasonally managed wetlands in the Grasslands Basin on the west-side 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 wetlands contain salt which, when drained to the San Joaquin River during the annual drawdown period, can negatively impact water quality and cause concern to downstream agricultural riparian water diverters. Recent environmental regulation, limiting discharges salinity to the San Joaquin River and primarily targeting agricultural non-point sources, now also targets return flows from seasonally managed wetlands. Real-time water quality management has been advocated as a means of continuously matching salt loads discharged from agricultural, wetland and municipal operations to the assimilative capacity of the San Joaquin River. Past attempts to build environmental monitoring and decision support systems (EDSS's) to implement this concept have enjoyed limited success for reasons that are discussed in this paper. These reasons are discussed in the context of more general challenges facing the successful implementation of a comprehensive environmental monitoring, modelling and decision support system for the San Joaquin River Basin.

  18. Real-Time Water Quality Monitoring and Habitat Assessment in the San Luis National Wildlife Refuge

    OpenAIRE

    Quinn, Nigel W.T.; Hanlon, Jeremy S.; Burns, Josephine R.; Stromayer, Karl A.K.; Jordan, Brandon M.; Ennis, Mike J.; Woolington, Dennis W.

    2005-01-01

    The project report describes a two year experiment to control wetland drainage to the San Joaquin River of California from the San Luis National Wildlife Refuge using a decision support system for real-time water quality management. This system required the installation and operation of one inlet and three drainage flow and water quality monitoring stations which allowed a simnple mass balance model to be developed of the seasonally managed wetlands in the study area. Remote sensing meth...

  19. Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, March-October 1990

    Science.gov (United States)

    Taylor, R. Lynn

    1995-01-01

    Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during March-October 1990, the second year of a multiyear data-collection program. The data will be used to document water-quality conditions prior to implementation of a proposal to reuse treated wastewater to irrigate city properties in Olmos Basin and Brackenridge Parks and to augment flows in the Olmos Creek/San Antonio River system.

  20. The three-dimensional geologic model used for the 2003 National Oil and Gas Assessment of the San Joaquin Basin Province, California: Chapter 7 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    Science.gov (United States)

    Hosford Scheirer, Allegra

    2013-01-01

    We present a three-dimensional geologic model of the San Joaquin Basin (SJB) that may be the first compilation of subsurface data spanning the entire basin. The model volume spans 200 × 90 miles, oriented along the basin axis, and extends to ~11 miles depth, for a total of more than 1 million grid nodes. This model supported the 2003 U.S. Geological Survey assessment of future additions to reserves of oil and gas in the SJB. Data sources include well-top picks from more than 3,200 wildcat and production wells, published cross sections, regional seismic grids, and fault maps. The model consists of 15 chronostratigraphic horizons ranging from the Mesozoic crystalline basement to the topographic surface. Many of the model units are hydrocarbon reservoir rocks and three—the Cretaceous Moreno Formation, the Eocene Kreyenhagen Formation, and the Miocene Monterey Formation—are hydrocarbon source rocks. The White Wolf Fault near the southern end of the basin divides the map volume into 2 separate fault blocks. The construction of a three-dimensional model of the entire SJB encountered many challenges, including complex and inconsistent stratigraphic nomenclature, significant facies changes across and along the basin axis, time-transgressive formation tops, uncertain correlation of outcrops with their subsurface equivalents, and contradictory formation top data. Although some areas of the model are better resolved than others, the model facilitated the 2003 resource assessment in several ways, including forming the basis of a petroleum system model and allowing a precise definition of assessment unit volumes.

  1. Simulations of Ground-Water Flow and Particle Pathline Analysis in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California

    Science.gov (United States)

    Burow, Karen R.; Jurgens, Bryant C.; Kauffman, Leon J.; Phillips, Steven P.; Dalgish, Barbara A.; Shelton, Jennifer L.

    2008-01-01

    Shallow ground water in the eastern San Joaquin Valley is affected by high nitrate and uranium concentrations and frequent detections of pesticides and volatile organic compounds (VOC), as a result of ground-water development and intensive agricultural and urban land use. A single public-supply well was selected for intensive study to evaluate the dominant processes affecting the vulnerability of public-supply wells in the Modesto area. A network of 23 monitoring wells was installed, and water and sediment samples were collected within the approximate zone of contribution of the public-supply well, to support a detailed analysis of physical and chemical conditions and processes affecting the water chemistry in the well. A three-dimensional, steady-state local ground-water-flow and transport model was developed to evaluate the age of ground water reaching the well and to evaluate the vulnerability of the well to nonpoint source input of nitrate and uranium. Particle tracking was used to compute pathlines and advective travel times in the ground-water flow model. The simulated ages of particles reaching the public-supply well ranged from 9 to 30,000 years, with a median of 54 years. The age of the ground water contributed to the public-supply well increased with depth below the water table. Measured nitrate concentrations, derived primarily from agricultural fertilizer, were highest (17 milligrams per liter) in shallow ground water and decreased with depth to background concentrations of less than 2 milligrams per liter in the deepest wells. Because the movement of water is predominantly downward as a result of ground-water development, and because geochemical conditions are generally oxic, high nitrate concentrations in shallow ground water are expected to continue moving downward without significant attenuation. Simulated long-term nitrate concentrations indicate that concentrations have peaked and will decrease in the public-supply well during the next 100 years

  2. Effects of smectite on the oil-expulsion efficiency of the Kreyenhagen Shale, San Joaquin Basin, California, based on hydrous-pyrolysis experiments

    Science.gov (United States)

    Lewan, Michael D.; Dolan, Michael P.; Curtis, John B.

    2014-01-01

    The amount of oil that maturing source rocks expel is expressed as their expulsion efficiency, which is usually stated in milligrams of expelled oil per gram of original total organic carbon (TOCO). Oil-expulsion efficiency can be determined by heating thermally immature source rocks in the presence of liquid water (i.e., hydrous pyrolysis) at temperatures between 350°C and 365°C for 72 hr. This pyrolysis method generates oil that is compositionally similar to natural crude oil and expels it by processes operative in the subsurface. Consequently, hydrous pyrolysis provides a means to determine oil-expulsion efficiencies and the rock properties that influence them. Smectite in source rocks has previously been considered to promote oil generation and expulsion and is the focus of this hydrous-pyrolysis study involving a representative sample of smectite-rich source rock from the Eocene Kreyenhagen Shale in the San Joaquin Basin of California. Smectite is the major clay mineral (31 wt. %) in this thermally immature sample, which contains 9.4 wt. % total organic carbon (TOC) comprised of type II kerogen. Compared to other immature source rocks that lack smectite as their major clay mineral, the expulsion efficiency of the Kreyenhagen Shale was significantly lower. The expulsion efficiency of the Kreyenhagen whole rock was reduced 88% compared to that of its isolated kerogen. This significant reduction is attributed to bitumen impregnating the smectite interlayers in addition to the rock matrix. Within the interlayers, much of the bitumen is converted to pyrobitumen through crosslinking instead of oil through thermal cracking. As a result, smectite does not promote oil generation but inhibits it. Bitumen impregnation of the rock matrix and smectite interlayers results in the rock pore system changing from water wet to bitumen wet. This change prevents potassium ion (K+) transfer and dissolution and precipitation reactions needed for the conversion of smectite to

  3. Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California

    Science.gov (United States)

    Downing, Bryan D.; Bergamaschi, Brian A.; Kraus, Tamara E.C.

    2017-07-11

    Executive SummaryThis report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). The purpose of this report is to synthesize the data available from a nutrient and water-quality HF (about every 15 minutes) monitoring network operated by the U.S. Geological Survey in the northern Delta. In this report, we describe the network and focus on the purpose of each station. We then present and discuss the available data, at various timescales—first at the monthly, seasonal, and inter-annual timescales, and second, for comparison, at the tidal and event timescales. As expected, we determined that there is substantial variability in nitrate-N concentrations at short timescales within hours, but also significant variability at longer timescales such as months or years. Resolving this variability is made possible by the HF data, with the largest variability caused by storms, tides, and diel biological processes. Given this large temporal variability, calculations of cumulative nutrient fluxes (for example, daily, monthly, or annual loads) is difficult without HF data. For example, in the Cache Slough, calculation of the annual load without the tidal variability resulted in a 30 percent underestimation of the true annual load value. We conclude that HF measurements are important for accurate determination of fluxes and loads in tidal environments, but, more importantly, provide important insights into processes and rates of nutrient cycling.This report, along with the other two reports of this series (Bergamaschi and others, 2017; Kraus, Bergamaschi, and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta. The first report in the series

  4. Hydraulic Balance, under three contrasting vegetable coverings in the San Cristobal River basin, Bogota

    International Nuclear Information System (INIS)

    De las salas, Gonzalo; Garcia Olmos, Carlos

    2000-01-01

    A hydrological balance fewer than three forest covers in the San Cristobal river watershed was done. Records of precipitation during one year under each canopy were registered along with measurements on the river stream of three micro watersheds adjacent to the forest canopies. The following parameters were evaluated: evapotranspiration, trough fall, interception, infiltration and water storage, which are discussed critically

  5. The lower San Pedro River: hydrology and flow restoration for biodiversity conservation

    Science.gov (United States)

    Jeanmarie Haney

    2005-01-01

    The lower San Pedro River, downstream from Benson, is a nearly unfragmented habitat containing perennial flow reaches that support riparian vegetation that serve as “stepping stones” for migratory species. The Nature Conservancy has purchased farm properties and retired agricultural pumping along the lower river, based largely on results from hydrologic analyses...

  6. Phytolith analysis in fluvial quaternary sediment (San Salvador and Palmar formation) Uruguay river and Argentina eastern

    International Nuclear Information System (INIS)

    Patterer, N.; Passeggi, E.; Zucol, A.; Brea, M.; Krohling, D.

    2012-01-01

    This work is about two microfossils fluvial units deposited by the Uruguay river during the Quaternary. These are San Salvador and Palmar formation (Plio-Pleistocene - Upper Pleistocene).The Palmar formation is a band of 4-15 km along the right bank of the Uruguay river outcropping from the eastern provinces of Corrientes and Entre Rios, to Concepcion del Uruguay

  7. The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

    Directory of Open Access Journals (Sweden)

    McLean L.D. Worsham

    2016-09-01

    Full Text Available The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13 species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures.

  8. The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

    Science.gov (United States)

    Worsham, McLean L. D.; Gibson, Randy; Huffman, David G.

    2016-01-01

    Abstract The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13) species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures. PMID:27853397

  9. Parnaíba and San Francisco rivers: traveler's fascination and technicians' rationality

    Directory of Open Access Journals (Sweden)

    Gercinair Silvério Gandara

    2013-02-01

    Full Text Available Considering that the environmental variable opens up the prospect of countless historical approaches, I will give attention (having Parnaíba and San Francisco river as scenery to the travelers' accounts,the reports of technicians and engineers, to the political speeches and governmental decisionsundertaken in order to promote better navigability in both rivers. I will also highlight the studies and services aimed to the removal of obstacles the environment from the Parnaíba and San Franciscorivers in the second half the nineteenth century and first half of the twentieth century.

  10. Real-Time Water Quality Monitoring and Habitat Assessment in theSan Luis National Wildlife Refuge

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Nigel W.T.; Hanlon, Jeremy S.; Burns, Josephine R.; Stromayer, Karl A.K.; Jordan, Brandon M.; Ennis, Mike J.; Woolington,Dennis W.

    2005-08-28

    The project report describes a two year experiment to control wetland drainage to the San Joaquin River of California from the San Luis National Wildlife Refuge using a decision support system for real-time water quality management. This system required the installation and operation of one inlet and three drainage flow and water quality monitoring stations which allowed a simple mass balance model to be developed of the seasonally managed wetlands in the study area. Remote sensing methods were developed to document long-term trends in wetland moist soil vegetation and soil salinity in response to management options such as delaying the initiation of seasonal wetland drainage. These environmental management tools provide wetland managers with some of the tools necessary to improve salinity conditions in the San Joaquin River and improve compliance with State mandated salinity objectives without inflicting long-term harm on the wild fowl habitat resource.

  11. REMOTE SENSING OF THE SEDIMENTATION PLUME OF THE RIVER SAN JUAN

    OpenAIRE

    Ballestero, Daniel

    2004-01-01

    The River San Juan (RSJ), in the border between Nicaragua and Costa Rica, is one the major rivers in Central America and drains the largest basin in the region (38570 km²) in terms of volume. Extending from Lago Cicibolca to the Caribbean Sea, the RSJ is an important source of freshwater, sediments, nutrients and pollutants to the continental shelf. Ecosystems degradation, contamination of water bodies and overexploitation of natural resources, particularly deforestation in the southern part ...

  12. Maps Suggest Transport and Source Processes of PM2.5 at 1 km x 1 km for the Whole San Joaquin Valley, Winter 2011 (Generalizations from DISCOVER-AQ)

    Science.gov (United States)

    Chatfield, R. B.

    2016-12-01

    We present interpreted data analysis using MAIAC (Multiangle implementation of Atmospheric Correction) retrievals and appropriate RAPid Update Cycle (RAP) meteorology to map respirable aerosol (PM2.5) for the period January and February, 2011. The San Joaquin Valley is one of the unhealthiest regions in the USA for PM2.5 and related morbidity. The methodology evaluated can be used for the entire moderate-resolution imaging spectrometer (MODIS, VIIRS) data record. Other difficult areas of the West: Riverside, CA, Salt Lake City, UT, and Doña Ana County, NM share similar difficulties and solutions. The maps of boundary layer depth for 11-16 hr local time from RAP allows us to interpret aerosol optical thickness as a concentration of particles in a nearly well-mixed box capped by clean air. That mixing is demonstrated by DISCOVER-AQ data and afternoon samples from the airborne measurements, P3B (on-board) and B200 (HSRL2 lidar). This data and the PM2.5 gathered at the deployment sites allowed us to estimate and then evaluate consistency and daily variation of the AOT to PM2.5 relationship. Mixed-effects modeling allowed a refinement of that relation from day to day; RAP mixed layers explained the success of previous mixed-effects modeling. Compositional, size-distribution, and MODIS angle-of-regard effects seem to describe the need for residual daily correction beyond ML depth. We report on an extension method to the entire San Joaquin Valley for all days with MODIS imagery using the permanent PM2.5 stations, evaluated for representativeness. Resulting map movies show distinct sources, particularly Interstate-5 (at 1km x 1km resolution) and the broader Bakersfield area. Accompanying winds suggest transport effects and variable pathways of pollution cleanout. Such estimates should allow morbidity/mortality studies. They should be also useful for actual model assimilations, where composition and sources are uncertain. We conclude with a description of new work to

  13. 76 FR 33778 - Notice of Intent To Collect Fees on Public Land in the San Joaquin River Gorge Special Recreation...

    Science.gov (United States)

    2011-06-09

    ... provided by the SJRG Business Plan, which outlines operational goals of the area and the purpose of the fee... would be used for expenses within the SJRG SRMA. In April 2010, the BLM published the SJRG Business Plan which outlines operational goals of the area and the purpose of the fee program. This Business Plan...

  14. Water quality modelling in the San Antonio River Basin driven by radar rainfall data

    Directory of Open Access Journals (Sweden)

    Almoutaz Elhassan

    2016-05-01

    Full Text Available Continuous monitoring of stream water quality is needed as it has significant impacts on human and ecological health and well-being. Estimating water quality between sampling dates requires model simulation based on the available geospatial and water quality data for a given watershed. Models such as the Soil and Water Assessment Tool (SWAT can be used to estimate the missing water quality data. In this study, SWAT was used to estimate water quality at a monitoring station near the outlet of the San Antonio River. Precipitation data from both rain gauges and weather radar were used to force the SWAT simulations. Virtual rain gauges which were based on weather radar data were created in the approximate centres of the 163 sub-watersheds of the San Antonio River Basin for SWAT simulations. This method was first tested in a smaller watershed in the middle of the Guadalupe River Basin resulting in increased model efficiency in simulating surface run-off. The method was then applied to the San Antonio River watershed and yielded good simulations for surface run-off (R2 = 0.7, nitrate (R2 = 0.6 and phosphate (R2 = 0.5 at the watershed outlet (Goliad, TX – USGS (United States Geological Survey gauge as compared to observed data. The study showed that the proper use of weather radar precipitation in SWAT model simulations improves the estimation of missing water quality data.

  15. Late quaternary geology in Desaguadero river basin, San Luis, Argentina

    International Nuclear Information System (INIS)

    Chiesa, J.; Strasser, E.; Gomez, D.; De Miguel, T.

    2007-01-01

    Absolute radiocarbon datings of the sedimentary successions have come to knowledge enabling us to distinguish the Pleistocene deposits from the supra-lying Holocene ones. A palaeo-environmental evolution is proposed considering climatic fluctuations at the time, their relation with the river unloadings of the Andean glaciers and that proposed for the palaeo-lake of Salina del Bebedero. Sediments are described on the basis of a detailed field sampling, textural analysis (sieved and Bouyoucos) and laboratory geo-chemicals. Their interpretation of the geologic evolution is considered to be very important since it is the only river course on this arid-semi-arid region linked to the reduction of glaciers in the Andes. The sedimentary succession is dominated by high percentages of laminated limes and with green-yellowish to greyish-brown-reddish tones deposited in watery environments of low energy such as lacustrine basins and extended plains of flood, which is why the evolution of the deposit is characterized by the contrast of the values of insolubles (clastic sediment and carbonate) versus solubles (insoluble saline). The climatic cycles dominant and proposed for the center-east Argentine region are identified considering the influence of Andean glaciers on the river systems and the water balances in plain semi-arid environments. (author)

  16. Riparian Communities along Longitudinal Gradients in Mexico's Northeastern San Juan River

    OpenAIRE

    Guerra, San Juana; Lizárraga-Mendiola, Liliana; Návar, José

    2016-01-01

    Abstract: This research was conducted in three major tributaries of Mexico's northeast San Juan River with the major objectives of: (a) describing the diversity-abundance of riparian trees, benthic insects and fish faunal communities and (b) associating the fish and benthic insect communities to riparian tree communities, flow quality, and discharge parameters along a longitudinal gradient of water stress. Regardless of the high spatial variability, two gradients could be identified using mul...

  17. Hazard evaluation of inorganics, singly and in mixtures, to Flannelmouth Sucker Catostomus latipinnis in the San Juan River, New Mexico

    Science.gov (United States)

    Hamilton, S.J.; Buhl, K.J.

    1997-01-01

    Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.

  18. The paradigm of paraglacial megafans of the San Juan river basin, Central Andes, Argentina

    Science.gov (United States)

    Suvires, Graciela M.

    2014-11-01

    The spatial distribution and several morphometric characteristics of the Quaternary alluvial fans of the San Juan River, in the province of San Juan, at the Central and Western part of Argentina, have been studied to classify them as paraglacial megafans, as well to ratify its depositional environmental conditions. The high sedimentary load exported by San Juan river from the Central Andes to the foreland depressions is estimated about 3,682,200 hm3. The large alluvial fans of Ullum-Zonda and Tulum valleys were deposited into deep tectonic depressions, during the Upper Pleistocene deglaciation stages. The outcome of collecting remotely sensed data, map and DEM data, geophysical data and much fieldwork gave access to morphometric, morphographic and morphogenetic data of these alluvial fans. The main drainage network was mapped on processed images using QGis (vers.2.0.1). Several fan morphometric parameters were measured, such as the size, the shape, the thickness, the surface areas and the sedimentary volume of exported load. The analyzed fans were accumulated in deep tectonic depressions, where the alluvium fill reaches 700 to 1200 m thick. Such fans do not reach the large size that other world megafans have, and this is due to tectonic obstacles, although the sedimentary fill average volume surpasses 514,000 hm3. The author proposes to consider Ullum-Zonda and Tulum alluvial fans as paraglacial megafans. According to the stratigraphic relationships of the tropical South American Rivers, the author considers that the San Juan paraglacial megafans would have occurred in the period before 24 ka BP , possibly corresponding to Middle Pleniglacial (ca 65-24ka BP). They record colder and more humid conditions compared with the present arid and dry conditions.

  19. 78 FR 1246 - Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the...

    Science.gov (United States)

    2013-01-08

    ...-FF08RSDC00] Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the... scoping with regard to the environmental impact statement (EIS) for the proposed Otay River Estuary... one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  20. Quaternary Geochronology, Paleontology, and Archaeology of the Upper San Pedro River Valley, Sonora, Mexico

    Science.gov (United States)

    Gaines, E. P.

    2013-12-01

    This poster presents the results of multi-disciplinary investigations of the preservation and extent of Quaternary fossil-bearing strata in the San Pedro River Valley in Sonora, Mexico. Geologic deposits in the portions of the San Pedro Valley in southern Arizona contain one of the best late Cenozoic fossil records known in North America and the best record of early humans and extinct mammals on the continent. The basin in the U.S. is one of the type locations for the Blancan Land Mammal Age. Hemiphilian and Irvingtonian fossils are common. Rancholabrean remains are widespread. Strata in the valley adjacent to the international border with Mexico have yielded the densest concentration of archaeological mammoth-kill sites known in the western hemisphere. Despite more than 60 years of research in the U.S., however, and the fact that over one third of the San Pedro River lies south of the international boundary, little has been known about the late Cenozoic geology of the valley in Mexico. The study reported here utilized extensive field survey, archaeological documentation, paleontological excavations, stratigraphic mapping and alluvial geochronology to determine the nature and extent of Quaternary fossil-bearing deposits in the portions of the San Pedro Valley in Sonora, Mexico. The results demonstrate that the Plio-Pleistocene fossil -bearing formations known from the valley in Arizona extend into the uppermost reaches of the valley in Mexico. Several new fossil sites were discovered that yielded the remains of Camelids, Equus, Mammuthus, and other Proboscidean species. Late Pleistocene archaeological remains were found on the surface of the surrounding uplands. AMS radiocarbon dating demonstrates the widespread preservation of middle- to late- Holocene deposits. However, the late Pleistocene deposits that contain the archaeological mammoth-kill sites in Arizona are absent in the valley in Mexico, and are now known to be restricted to relatively small portions of

  1. Alleviating dam impacts along the transboundary Se San River in northeast Cambodia : a review of the rapid environmental impact assessment on the Cambodian part of the Se San River due to hydropower development in Vietnam (July 2007 version)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-02-15

    Probe International has reviewed 2 reports regarding the environmental impact assessment (EIA) on the Cambodian part of the Se San River resulting from hydropower development in Vietnam. Both reports were prepared for Electricity of Vietnam (EVN), the project owner and developer. The operation of 3 large hydro dams on the upper Se San River has disrupted flow in downstream Cambodia where more than 28,000 people depend on the river for drinking water, irrigation, fishing, livestock watering and transportation. Probe International's focus is on mitigating and compensating for affected communities in downstream Cambodia. Their review of the EIAs recommends that Electricity of Vietnam consider switching from peaking to base load operations at its upper Se San hydro dams to mitigate the impacts in downstream Cambodia. The downstream impacts of EVN dams on the Se San River include loss of life, property, livelihood and habitat; malnutrition; loss of wet season rice production; reduced fish catches; food security at risk; loss of fish protein; loss of river bank agriculture; reduced availability of plants for food and medicine; river bank erosion; reservoir erosion and downstream turbidity; increased transportation risks; loss of fisheries habitat; increased pressure on upland forests; disrupted riverine ecosystem; and disrupted fish migration. The EIA recommendations include the re-regulation of the Se San 4A reservoir; operational changes to reduce downstream fluctuations and erosion; monitoring impact of operations on water quantity and quality downstream; algal monitoring; establishment of early warning system for spillway release; prolonging the wet season filling of the reservoir; reducing nutrient inputs to the rivers and reservoirs and a fish stocking program. 6 figs., 1 appendix.

  2. Evaluation of the hurricanes Gustav and Ike impact on mud from San Diego River using nuclear and geochemical techniques

    International Nuclear Information System (INIS)

    Diaz Rizo, O.; Gelen Rudnikas, A.; D'Alessandro Rodriguez, K.; Arado Lopez, J. O.; Dominguez Rodriguez, R.; Gonzalez Hernandez, P.; Melian Rodriguez, C.M.; Suarez Munnoz, M.; Fagundo Castillo, J. R.; Blanco Padilla, D.

    2011-01-01

    Effects induced by the hurricanes Gustav and Ike on San Diego River mud characteristics have been studied. X-ray fluorescence analysis, gamma spectrometry and measurement of some physic-chemical characteristics in mud samples, collected before and after hurricane impacts, shows that hurricanes induced changes in mud major composition and in some other mud characteristics, affecting its properties for therapeutic uses. The average sedimentation rate determined by gamma spectrometry in San Diego River outlet permit to estimate that the original mud characteristics will be recovered never before than 5-7 years. (Author)

  3. Evaluation of the hurricanes Gustav and Ike impact on healing mud from San Diego River using nuclear and geochemical techniques

    International Nuclear Information System (INIS)

    Diaz Rizo, Oscar; Gelen Rudnikas, Alina Katia; Rodriguez, D'Alessandro; Arado Lopez, Juana O.; Dominguez Rodriguez, Roberto; Gonzalez Hernandez, Patricia; Melian Rodriguez, Clara M.; Suarez Munnoz, Margaret; Fagundo Castillo, Juan R.; Blanco Padilla, Dagoberto

    2011-01-01

    Effects induced by the hurricanes Gustav and Ike on San Diego River mud characteristics have been studied. X-ray fluorescence analysis, gamma spectrometry and measurement of some physico-chemical characteristics in mud samples, collected before and after hurricane impacts, shows that hurricanes induced changes in mud major composition and in some other mud characteristics. The average sedimentation rate determined by gamma spectrometry in San Diego River outlet permitted to estimate that the original mud characteristics will be recovered never before than 5-7 years. Further studies of the influence of mud characteristics changes due the hurricanes impact in mud therapeutic properties are recommended.(author)

  4. Development and Testing of Physically-Based Methods for Filling Gaps in Remotely Sensed River Data: Annual Report Year 2

    Science.gov (United States)

    2012-09-30

    near Deerlodge Park to support a USGS surface-water modeling study. Similar modeling projects on the San Joaquin and Sheboygan River were aided over...September 5-7, 2012, San Jose, Costa Rica, 8p. Nelson, J.M., McDonald, R.R., Kinzel, P.J., and Legleiter, C.J., 2011, Using computational models to...of the International Conference on Fluvial Hydraulics, September 5-7, 2012, San Jose, Costa Rica, 8p. *Nelson, J.M., McDonald, R.R., Kinzel, P.J

  5. Investigating Historic Parcel Changes to Understand Land Use Trends: A Methodology and Application for the San Pedro River Watershed

    Science.gov (United States)

    Long-term land use and land cover change, and the associated impacts, pose critical challenges to sustaining healthy communities and ecosystems. In this study, a methodology was developed to use parcel data to evaluate land use trends in southeast Arizona’s San Pedro River Water...

  6. Gravity data from the San Pedro River Basin, Cochise County, Arizona

    Science.gov (United States)

    Kennedy, Jeffrey R.; Winester, Daniel

    2011-01-01

    The U.S. Geological Survey, Arizona Water Science Center in cooperation with the National Oceanic and Atmospheric Administration, National Geodetic Survey has collected relative and absolute gravity data at 321 stations in the San Pedro River Basin of southeastern Arizona since 2000. Data are of three types: observed gravity values and associated free-air, simple Bouguer, and complete Bouguer anomaly values, useful for subsurface-density modeling; high-precision relative-gravity surveys repeated over time, useful for aquifer-storage-change monitoring; and absolute-gravity values, useful as base stations for relative-gravity surveys and for monitoring gravity change over time. The data are compiled, without interpretation, in three spreadsheet files. Gravity values, GPS locations, and driving directions for absolute-gravity base stations are presented as National Geodetic Survey site descriptions.

  7. Quantifying and valuing ecosystem services: An application of ARIES to the San Pedro River basin, USA

    Science.gov (United States)

    Bagstad, Kenneth J.; Semmens, Darius J.; Villa, Ferdinando; Johnson, Gary

    2014-01-01

    A large body of research exists that identifies and values ecosystem services - the benefits that ecosystems provide to humans (MA, 2005) - and their underlying ecological processes. However, the development of software decision support tools that integrate ecology, economics and geography that can be independently used within the public, private, academic and NGO sectors is a more recent phenomenon (Ruhl et al., 2007; Daily et al., 2009). Spurred by growing demand for more sophisticated analysis of the social and economic consequences of land management decisions, the US Department of Interior - Bureau of Land Management (BLM) launched a pilot project with the US Geological Survey (USGS) to assess the usefulness and feasibility of ecosystem service assessment and valuation tools to provide inputs to decision-making. The project analysed ecosystem services in the US portion of the San Pedro River watershed, which includes the BLM-managed San Pedro Riparian National Conservation Area (SPRNCA), to improve the understanding of complex social and ecological relationships that transcend administrative divisions. The BLM manages some 99 million hectares, primarily in the western United States, and 283 million hectares of sub-surface mineral estate. BLM's multiple-use mission requires that it appropriately balance non-extractive uses such as habitat conservation, recreation and archaeological heritage protection and the extractive use of resources such as timber, oil and gas, coal, uranium, and other minerals.

  8. Conservation Opportunities - San Joaquin Valley [ds422

    Data.gov (United States)

    California Natural Resource Agency — The California Departments of Fish and Game, Parks and Recreation, and Transportation (Caltrans) are collaborating to improve planning information for wildlife...

  9. Wildlife Linkages - San Joaquin Valley [ds417

    Data.gov (United States)

    California Natural Resource Agency — The California Departments of Fish and Game, Parks and Recreation, and Transportation (Caltrans) are collaborating to improve planning information for wildlife...

  10. Specialty Reserves - San Joaquin Valley [ds418

    Data.gov (United States)

    California Natural Resource Agency — The California Departments of Fish and Game, Parks and Recreation, and Transportation (Caltrans) are collaborating to improve planning information for wildlife...

  11. Wildlife Corridors - San Joaquin Valley [ds423

    Data.gov (United States)

    California Natural Resource Agency — The California Departments of Fish and Game, Parks and Recreation, and Transportation (Caltrans) are collaborating to improve planning information for wildlife...

  12. California GAMA Special Study: Importance of River Water Recharge to Selected Groundwater Basins

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Ate [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moran, Jean E. [California State Univ. East Bay (CalState), Hayward, CA (United States); Singleton, Michael J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-03-21

    River recharge represents 63%, 86% and 46% of modern groundwater in the Mojave Desert, Owens Valley, and San Joaquin Valley, respectively. In pre-modern groundwater, river recharge represents a lower fraction: 36%, 46%, and 24% respectively. The importance of river water recharge in the San Joaquin valley has nearly doubled and is likely the result of a total increase of recharge of 40%, caused by river water irrigation return flows. This emphasizes the importance of recharge of river water via irrigation for renewal of groundwater resources. Mountain front recharge and local precipitation contribute to recharge of desert groundwater basins in part as the result of geological features focusing scarce precipitation promoting infiltration. River water recharges groundwater systems under lower temperatures and with larger water table fluctuations than local precipitation recharge. Surface storage is limited in time and volume, as evidenced by cold river recharge temperatures resulting from fast recharge, compared to the large capacity for subsurface storage. Groundwater banking of seasonal surface water flows therefore appears to be a natural and promising method for increasing the resilience of water supply systems. The distinct isotopic and noble gas signatures of river water recharge, compared to local precipitation recharge, reflecting the source and mechanism of recharge, are valuable constraints for numerical flow models.

  13. Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, April - September 1989

    Science.gov (United States)

    Taylor, R. Lynn; Ferreira, Rodger F.

    1995-01-01

    Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during April-September 1989. Benthic macroinvertebrate, periphyton, and phytoplankton communities were sampled at three sites along the Olmos Creek/San Antonio River system. Total mean densities of benthic macroinvertebrates for the three sites ranged from 670 to 10,000 organisms per square meter. The most abundant macroinvertebrates were the class Insecta (insects). Total densities of periphyton ranged from 2,900 to 110,000 cells per square millimeter. Cyanophyta (blue-green algae) and Bacillariophyta (diatoms) were the predominant periphyton organisms. Total densities of phyto- plankton ranged from 5,000 to 47,000 cells per square milliliter. Blue-green algae accounted for more than one- half of the phytoplankton in each sample. Hardness ranged from 160 to 250 milligrams per liter as calcium carbonate, and alkalinity ranged from 130 to 220 milligrams per liter as calcium carbonate. The largest dissolved nitrite concentration was 0.038 milligram per liter. The largest total phosphorus concentration was 0.150 milligram per liter, over one-half of which was dissolved orthophosphate. Total aluminum and total iron were the only trace elements in water to exceed the reporting threshold by large concen- trations. Total aluminum concentrations ranged from 70 to 280 micrograms per liter, and total iron concentrations ranged from 70 to 340 micrograms per liter. Lead was the most prominent trace element in bottom-material samples, with concentrations ranging from 30 to 230 micrograms per gram.

  14. Origins of the Salado, Seven Rivers, and San Andres salt margins in Texas and New Mexico: Revision 1: Topical report

    International Nuclear Information System (INIS)

    Boyd, S.D.; Murphy, P.J.

    1987-02-01

    The present boundaries of the San Andres, Seven Rivers, and Salado salts generally lie along the periphery of the Palo Duro and Tucumcari Basins. Various geologic mechanisms occurring singularly or in combination determined the positions of the salt margins. These mechanisms include nondeposition of salt and syndepositional and postdepositional dissolution. In New Mexico, San Andres units pinch out against the Pedernal and Sierra Grande Uplifts, indicating that nondeposition established the original salt margins there. Syndepositional dissolution of exposed Upper San Andres salts occurred in response to Guadalupian upwarp of the basin margins. Triassic erosion differentially removed Permian salt-bearing formations along the uplifts. Late Tertiary dissolution is indicated by fill of north-south trending collapse valleys. In Texas, Guadalupian upwarp along the Amarillo Uplift caused pinchout of Units 2 and 3 in the Lower San Andres and influenced the deposition of subsequent salt-bearing strata. The discontinuity of Upper San Andres evaporites across the Amarillo Uplift suggests syndepositional dissolution. Along the eastern and northeastern basin margin, dissolution may have accompanied Triassic erosion of locally uplifted Upper Permian strata. Tertiary dissolution is recognized beneath anomalously thick Ogallala Formation sections that overlie collasped Permian strata. 49 refs., 31 figs., 2 tabs

  15. Evaluation of NDVI to assess avian abundance and richness along the upper San Pedro River

    Science.gov (United States)

    McFarland, T.M.; van Riper, Charles; Johnson, G.E.

    2012-01-01

    Remote-sensing models have become increasingly popular for identifying, characterizing, monitoring, and predicting avian habitat but have largely focused on single bird species. The Normalized Difference Vegetation Index (NDVI) has been shown to positively correlate with avian abundance and richness and has been successfully applied to southwestern riparian systems which are uniquely composed of narrow bands of vegetation in an otherwise dry landscape. Desert riparian ecosystems are important breeding and stopover sites for many bird species but have been degraded due to altered hydrology and land management practices. Here we investigated the use of NDVI, coupled with vegetation, to model the avian community structure along the San Pedro River, Arizona. We also investigated how vegetation and physical features measured locally compared to those data that can be gathered through remote-sensing. We found that NDVI has statistically significant relationships with both avian abundance and species richness, although is better applied at the individual species level. However, the amount of variation explained by even our best models was quite low, suggesting that NDVI habitat models may not presently be an accurate tool for extensive modeling of avian communities. We suggest additional studies in other watersheds to increase our understanding of these bird/NDVI relationships.

  16. Analysis of the Transport and Fate of Metals Released From the Gold King Mine in the Animas and San Juan Rivers

    Science.gov (United States)

    This project’s objectives were to provide analysis of water quality following the release of acid mine drainage in the Animas and San Juan Rivers in a timely manner to 1) generate a comprehensive picture of the plume at the river system level, 2) help inform future monitoring eff...

  17. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

    2013-01-01

    Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

  18. Implications of using On-Farm Flood Flow Capture to recharge groundwater and mitigate flood risks along the Kings River, CA

    OpenAIRE

    Bachand, P.A.M.; Horwath, W.R.; Roy, S.; Choperena, J.; Cameron, D.

    2012-01-01

    Two large hydrologic issues face the Kings Basin, severe and chronic overdraft of about 0.16M ac-ft annually, and flood risks along the Kings River and the downstream San Joaquin River. Since 1983, these floods have caused over $1B in damage in today’s dollars. Capturing flood flows of sufficient volume could help address these two pressing issues which are relevant to many regions of the Central Valley and will only be exacerbated with climate change. However, the Kings River has high vari...

  19. Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Middle San Luis Rey River, San Diego County, southern California—2017 data summary

    Science.gov (United States)

    Allen, Lisa D.; Howell, Scarlett L.; Kus, Barbara E.

    2018-04-20

    We surveyed for Least Bell’s Vireos (LBVI) (Vireo bellii pusillus) and Southwestern Willow Flycatchers (SWFL) (Empidonax traillii extimus) along the San Luis Rey River, between College Boulevard in Oceanside and Interstate 15 in Fallbrook, California (middle San Luis Rey River), in 2017. Surveys were conducted from April 13 to July 11 (LBVI) and from May 16 to July 28 (SWFL). We found 146 LBVI territories, at least 107 of which were occupied by pairs. Five additional transient LBVIs were detected. LBVIs used five different habitat types in the survey area: mixed willow, willow-cottonwood, willow-sycamore, riparian scrub, and upland scrub. Forty-four percent of the LBVIs occurred in habitat characterized as mixed willow and 89 percent of the LBVI territories occurred in areas with greater than 50 percent native plant cover. Of 16 banded LBVIs detected in the survey area, 8 had been given full color-band combinations prior to 2017. Four other LBVIs with single (natal) federal bands were recaptured and banded in 2017. Three LBVIs with single dark blue federal bands indicating that they were banded as nestlings on the lower San Luis Rey River and one LBVI with a single gold federal band indicating that it was banded as a nestling on Marine Corps Base Camp Pendleton (MCBCP) could not be recaptured for identification. One banded LBVI emigrated from the middle San Luis Rey River to the lower San Luis Rey River in 2017.One resident SWFL territory and one transient Willow Flycatcher of unknown subspecies (WIFL) were observed in the survey area in 2017. The resident SWFL territory, which was comprised of mixed willow habitat (5–50 percent native plant cover), was occupied by a single male from May 22 to June 21, 2017. No evidence of pairing or nesting activity was observed. The SWFL male was banded with a full color-combination indicating that he was originally banded as a nestling on the middle San Luis Rey River in 2014 and successfully bred in the survey area in 2016

  20. Maps of the Bonsall area of the San Luis Rey River valley, San Diego County, California, showing geology, hydrology, and ground-water quality

    Science.gov (United States)

    Izbicki, John A.

    1985-01-01

    In November 1984, 84 wells and 1 spring in the Bonsall area of the San Luis Rey River valley were inventoried by U.S. Geological Survey personnel. Depth to water in 38 wells ranged from 1.3 to 38 ft and 23 wells had depths to water less than 10 feet. Dissolved solids concentration of water from 29 wells and 1 spring sampled in autumn 1983 and spring 1984 ranged from 574 to 2,370 mgs/L. Groundwater with a dissolved solids concentration less than 1,000 mgs/L was generally restricted to the eastern part of the aquifer. The total volume of alluvial fill in the Bonsall area is 113,000 acre-feet; the amount of groundwater storage available in the alluvial aquifer is 18,000 acre-feet. The alluvial aquifer is, in part, surrounded and underlain by colluvium and weathered crystalline rock that add some additional groundwater storage capacity to the system. Data in this report are presented on five maps showing well locations , thickness of alluvial fill, water level contours in November 1983 and hydrographs of selected wells, groundwater quality in spring 1960 and graphs showing changes in dissolved solids concentrations of water from selected wells with time, and groundwater quality in spring 1984. This report is part of a larger cooperative project between the Rainbow Municipal Irrigation District and the U.S. Geological Survey. The purpose of the larger project is to develop an appropriate groundwater management plan for the Bonsall area of the San Luis Rey River valley. (USGS)

  1. Mapping the Distribution and Biomass of Emergent Aquatic Plants in the Sacramento-San Joaquin River Delta of California Using Landsat Imagery Analysis

    Science.gov (United States)

    Potter, Christopher

    2015-01-01

    This study evaluated the cost-effective and timely use of Landsat imagery to map and monitor emergent aquatic plant biomass and to filter satellite image products for the most probable locations of water hyacinth coverage in the Delta based on field observations collected immediately after satellite image acquisition.

  2. Elements of a decision support system for real-time management ofdissolved oxygen in the San Joaquin River deep water ship channel

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T.; Jacobs, Karl; Chen, Carl W.; Stringfellow, WilliamT.

    2004-07-15

    A decision support system (DSS) has been designed and will be implemented over the next three years to assist in the control and management of episodes of low dissolved oxygen (DO) in a Deep Water Ship Channel (DWSC), located near Stockton, California. The DSS integrates three information technology functions. The first part is the collection and management of data on flow, pollution loads and water quality. The second part is the simulation model which can forecast the dissolved oxygen sag in the DWSC and determine management actions necessary to improve dissolved oxygen concentrations. The third part is the graphical user interface, which facilitates the computer simulations and posting of the forecasted dissolved oxygen and remedial measures to a stakeholder group for implementations.

  3. Sediment Dynamics Over a Stable Point bar of the San Pedro River, Southeastern Arizona

    Science.gov (United States)

    Hamblen, J. M.; Conklin, M. H.

    2002-12-01

    Streams of the Southwest receive enormous inputs of sediment during storm events in the monsoon season due to the high intensity rainfall and large percentages of exposed soil in the semi-arid landscape. In the Upper San Pedro River, with a watershed area of approximately 3600 square kilometers, particle size ranges from clays to boulders with large fractions of sand and gravel. This study focuses on the mechanics of scour and fill on a stable point bar. An innovative technique using seven co-located scour chains and liquid-filled, load-cell scour sensors characterized sediment dynamics over the point bar during the monsoon season of July to September 2002. The sensors were set in two transects to document sediment dynamics near the head and toe of the bar. Scour sensors record area-averaged sediment depths while scour chains measure scour and fill at a point. The average area covered by each scour sensor is 11.1 square meters. Because scour sensors have never been used in a system similar to the San Pedro, one goal of the study was to test their ability to detect changes in sediment load with time in order to determine the extent of scour and fill during monsoonal storms. Because of the predominantly unconsolidated nature of the substrate it was hypothesized that dune bedforms would develop in events less than the 1-year flood. The weak 2002 monsoon season produced only two storms that completely inundated the point bar, both less than the 1-year flood event. The first event, 34 cms, produced net deposition in areas where Johnson grass had been present and was now buried. The scour sensor at the lowest elevation, in a depression which serves as a secondary channel during storm events, recorded scour during the rising limb of the hydrograph followed by pulses we interpret to be the passage of dunes. The second event, although smaller at 28 cms, resulted from rain more than 50 km upstream and had a much longer peak and a slowly declining falling limb. During the

  4. Influence of natural and anthropogenic factors on the distribution of xerothermic plants in the lower San river valley (SE Poland

    Directory of Open Access Journals (Sweden)

    Rafał Krawczyk

    2012-12-01

    Full Text Available The aim of the present study was to describe the distribution of xerothermic species of vascular plants in the lower San River valley and the relationship between their density and the intensity of selected environmental (natural and anthropogenic factors. Xerothermic species occurred more frequently in the present valley floor compared to the glacial terrace. Within the present valley, the highest density was observed in the floodplain. The examined species also occurred more often on steep slopes of the valley, at the margins of the present valley terraces, and in the area of occurrence of aeolian sands. Moreover, a positive correlation has been found between the number of xerothermic species and the area of polyhemeroby ecosystems. The distribution of xero- and thermophilous species is determined by natural edaphic and geomorphological factors as well as anthropogenic ones (land use, lowering of the groundwater level as a result of river regulation.

  5. Annual compilation and analysis of hydrologic data for Escondido Creek, San Antonio River basin, Texas

    Science.gov (United States)

    Reddy, D.R.

    1971-01-01

    IntroductionHistory of Small Watershed Projects in TexasThe U.S. Soil Conservation Service is actively engaged in the installation of flood and soil erosion reducing measures in Texas under the authority of the "Flood Control Act of 1936 and 1944" and "Watershed Protection and Flood Prevention Act" (Public Law 566), as amended. The Soil Conservation Service has found a total of approximately 3,500 floodwater-retarding structures to be physically and economically feasible in Texas. As of September 30, 1970, 1,439 of these structures had been built.This watershed-development program will have varying but important effects on the surface and ground-water resources of river basins, especially where a large number of the floodwater-retarding structures are built. Basic hydrologic data under natural and developed conditions are needed to appraise the effects of the structures on the yield and mode of occurrence of runoff.Hydrologic investigations of these small watersheds were begun by the Geological Survey in 1951 and are now being made in 12 study areas (fig. 1). These investigations are being made in cooperation with the Texas Water Development Board, the Soil Conservation Service, the San Antonio River Authority, the city of Dallas, and the Tarrant County Water Control and Improvement District No. 1. The 12 study areas were chosen to sample watershed having different rainfall, topography, geology, and soils. In five of the study areas, (North, Little Elm, Mukewater, little Pond-North Elm, and Pin Oak Creeks), streamflow and rainfall records were collected prior to construction of the floodwater-retarding structures, thus affording the opportunity for analyses of the conditions "before and after" development. A summary of the development of the floodwater-retarding structures in each study areas of September 30, 1970, is shown in table 1.Objectives of the Texas Small Watersheds ProjectThe purpose of these investigations is to collect sufficient data to meeting the

  6. Mercury Bioaccumulation in Fish in a Region Affected by Historic Gold Morning: The South Yuba River, Deer Creek, and Bear River Watersheds, California, 1999

    National Research Council Canada - National Science Library

    May, Jason T; Hothem, Roger L; Alpers, Charles N; Law, Matthew A

    2000-01-01

    Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento-San Joaquin Delta and the San...

  7. Southern San Andreas Fault Slip History Refined Using Pliocene Colorado River Deposits in the Western Salton Trough

    Science.gov (United States)

    Dorsey, R. J.; Bennett, S. E. K.; Housen, B. A.

    2016-12-01

    Tectonic reconstructions of Pacific-North America plate motion in the Salton Trough region (Bennett et al., 2016) are constrained by: (1) late Miocene volcanic rocks that record 255 +/-10 km of transform offset across the northern Gulf of California since 6 Ma (average 42 mm/yr; Oskin and Stock, 2003); and (2) GPS data that show modern rates of 50-52 mm/yr between Pacific and North America plates, and 46-48 mm/yr between Baja California (BC) and North America (NAM) (Plattner et al., 2007). New data from Pliocene Colorado River deposits in the Salton Trough provide an important additional constraint on the geologic history of slip on the southern San Andreas Fault (SAF). The Arroyo Diablo Formation (ADF) in the San Felipe Hills SW of the Salton Sea contains abundant cross-bedded channel sandstones deformed in the dextral Clark fault zone. The ADF ranges in age from 4.3 to 2.8 Ma in the Fish Creek-Vallecito basin, and in the Borrego Badlands its upper contact with the Borrego Formation is 2.9 Ma based on our new magnetostratigraphy. ADF paleocurrent data from a 20-km wide, NW-oriented belt near Salton City record overall transport to the SW (corrected for bedding dip, N=165), with directions ranging from NW to SE. Spatial domain analysis reveals radial divergence of paleoflow to the: W and NW in the NW domain; SW in the central domain; and S in the SE domain. Data near Borrego Sink, which restores to south of Salton City after removing offset on the San Jacinto fault zone, show overall transport to the SE. Pliocene patterns of radial paleoflow divergence strongly resemble downstream bifurcation of fluvial distributary channels on the modern Colorado River delta SW of Yuma, and indicate that Salton City has translated 120-130 km NW along the SAF since 3 Ma. We propose a model in which post-6 Ma BC-NAM relative motion gradually accelerated to 50 mm/yr by 4 Ma, continued at 50 mm/yr from 4-1 Ma, and decreased to 46 mm/yr from 1-0 Ma (split equally between the SAF and

  8. Environmental Setting of the Lower Merced River Basin, California

    Science.gov (United States)

    Gronberg, Jo Ann M.; Kratzer, Charles R.

    2006-01-01

    In 1991, the U.S. Geological Survey began to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology as part of the National Water-Quality Assessment (NAWQA) Program. As part of this program, the San Joaquin-Tulare Basins study unit is assessing parts of the lower Merced River Basin, California. This report provides descriptions of natural and anthropogenic features of this basin as background information to assess the influence of these and other factors on water quality. The lower Merced River Basin, which encompasses the Mustang Creek Subbasin, gently slopes from the northeast to the southwest toward the San Joaquin River. The arid to semiarid climate is characterized by hot summers (highs of mid 90 degrees Fahrenheit) and mild winters (lows of mid 30 degrees Fahrenheit). Annual precipitation is highly variable, with long periods of drought and above normal precipitation. Population is estimated at about 39,230 for 2000. The watershed is predominately agricultural on the valley floor. Approximately 2.2 million pounds active ingredient of pesticides and an estimated 17.6 million pounds active ingredient of nitrogen and phosphorus fertilizer is applied annually to the agricultural land.

  9. Heavy metals in water of the San Pedro River in Chihuahua, Mexico and its potential health risk

    Directory of Open Access Journals (Sweden)

    Melida Gutierrez

    2008-06-01

    Full Text Available The objective of this study was to determine the seasonal and downstream water quality variations of the San Pedro River in Chihuahua, Mexico. Water samples were collected monthly from October 2005 to August 2006 in triplicate, totaling 165 water samples. The five sampling locations were: below the Francisco I. Madero dam (LP; between Rosales and Delicias (RD; Meoqui (M; El Torreon (ET, and Julimes (LJ. The levels of As, Be, Ca, Cd, Co, Cu, Cr, Fe, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Ta, V and Zn were measured using an Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES Perkin Elmer 2100. In addition, temperature, pH, electrical conductivity and total and fecal coliformes were determined. The statistical analysis considered a factorial treatment design; where factor A was the location point and factor B was sampling date. In addition, a multivariate technique looking for principal components was performed. The results indicated that some samples exceeded Mexican standards for As, Be, Ca, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sb, Se, Sr and Zn. The As level must be considered for a red flag to the communities along the Rio San Pedro because both the monthly average level (0.10 mg L-1 and location (0.10 mg L-1 exceeded the Mexican and International norms. The multivariate analysis showed a predominant aggregation at the LP location, meaning that there was a predominance of As, Sr, Fe and Li. At the rest of the locations the elements did not present a tendency for aggregation. Statistics applied to sampling month showed that December, January, March and April were aggregated in a negative quadrant of component 1 indicating a predominance of V, Ni, Be, Fe and As. Overall, the results confirmed that this stretch of the San Pedro River is contaminated with heavy metals and other contaminants that might affect human health as well as the health of the ecosystem.

  10. Heavy metals in water of the San Pedro River in Chihuahua, Mexico and its potential health risk

    Science.gov (United States)

    Gutiérrez, Roberto L.; Rubio-Arias, Hector; Quintana, Ray; Ortega, Juan Angel; Gutierrez, Melida

    2008-01-01

    The objective of this study was to determine the seasonal and downstream water quality variations of the San Pedro River in Chihuahua, Mexico. Water samples were collected monthly from October 2005 to August 2006 in triplicate, totaling 165 water samples. The five sampling locations were: below the Francisco I. Madero dam (LP); between Rosales and Delicias (RD); Meoqui (M); El Torreon (ET), and Julimes (LJ). The levels of As, Be, Ca, Cd, Co, Cu, Cr, Fe, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Ta, V and Zn were measured using an Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) Perkin Elmer 2100. In addition, temperature, pH, electrical conductivity and total and fecal coliformes were determined. The statistical analysis considered a factorial treatment design; where factor A was the location point and factor B was sampling date. In addition, a multivariate technique looking for principal components was performed. The results indicated that some samples exceeded Mexican standards for As, Be, Ca, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sb, Se, Sr and Zn. The As level must be considered for a red flag to the communities along the Rio San Pedro because both the monthly average level (0.10 mg L−1) and location (0.10 mg L−1) exceeded the Mexican and International norms. The multivariate analysis showed a predominant aggregation at the LP location, meaning that there was a predominance of As, Sr, Fe and Li. At the rest of the locations the elements did not present a tendency for aggregation. Statistics applied to sampling month showed that December, January, March and April were aggregated in a negative quadrant of component 1 indicating a predominance of V, Ni, Be, Fe and As. Overall, the results confirmed that this stretch of the San Pedro River is contaminated with heavy metals and other contaminants that might affect human health as well as the health of the ecosystem. PMID:18678922

  11. Application of hydrologic tools and monitoring to support managed aquifer recharge decision making in the Upper San Pedro River, Arizona, USA

    Science.gov (United States)

    Lacher, Laurel J.; Turner, Dale S.; Gungle, Bruce W.; Bushman, Brooke M.; Richter, Holly E.

    2014-01-01

    The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr). Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.

  12. Application of Hydrologic Tools and Monitoring to Support Managed Aquifer Recharge Decision Making in the Upper San Pedro River, Arizona, USA

    Directory of Open Access Journals (Sweden)

    Laurel J. Lacher

    2014-11-01

    Full Text Available The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr. Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.

  13. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  14. Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Johnson, Glenn E.; van Riper, Charles

    2014-01-01

    Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and richness of bird groups, such as all breeding birds, insectivorous birds, and riparian specialists, and higher relative abundance of many individual species—including several avian species of conservation concern. Chapter 2.—We conducted bird surveys in riparian areas along the upper San Pedro River in southeastern Arizona (United States) and northern Sonora (Mexico) in order to describe factors influencing bird community dynamics and the distribution and abundance of species, particularly those of conservation concern. These surveys were also used to document the effects of the ecosystem-altering activities of a recently reintroduced beavers (Castor canadensis). Chapter 3.—We reviewed Southwestern Willow Flycatcher (Empidonax traillii extimus) nest records and investigated the potential for future breeding along the upper San Pedro River in southeastern Arizona, where in July 2005 we encountered the southernmost verifiable nest attempt for the species. Continued conservation and management of the area’s riparian vegetation and surface water has potential to contribute additional breeding sites for this endangered Willow Flycatcher subspecies. Given the nest record along the upper San Pedro River and the presence of high-density breeding sites to the north, the native cottonwood-willow forests of the upper San Pedro River could become increasingly important to E. t. extimus recovery, especially considering the anticipated effect of the tamarisk leaf beetle (Diorhabda carinulata) on riparian habitat north of the region.

  15. Assessment of goods and valuation of ecosystem services (AGAVES) San Pedro River Basin, United States and Mexico

    Science.gov (United States)

    Semmens, Darius; Kepner, William; Goodrich, David

    2010-01-01

    A consortium of federal, academic, and nongovernment organization (NGO) partners have established a collaborative research enterprise in the San Pedro River Basin to develop methods, standards, and tools to assess and value ecosystem goods and services. The central premise of ecosystem services research is that human condition is intrinsically linked to the environment. Human health and well-being (including economic prosperity) depend on important supporting, regulating, provisioning, and cultural services that we derive from our surrounding ecosystems. The AGAVES project is intended as a demonstration study for incorporating ecosystem services information into resource management policy and decisionmaking. Accordingly, a nested, multiscale project design has been adopted to address a range of stakeholder information requirements. This design will further facilitate an evaluation of how well methods developed in this project can be transferred to other areas.

  16. Surface Water Geochemistry, Sediment, and Field Parameters During Snowmelt and Monsoons in the New Mexico Reach of the Animas and San Juan Rivers, 2016

    Science.gov (United States)

    Blake, J.; Brown, J. E.; Mast, A.

    2017-12-01

    Following the release of three million gallons of metals laden surface water from the Gold King Mine in August 2015, surface-water samples were collected in the New Mexico reach of the Animas and San Juan Rivers during 2016 snowmelt and in the Animas River during three 2016 monsoonal storms. These samples were evaluated for dissolved (turbidity and specific conductance can provide insight to changes in concentrations of the river on a finer time scale. Regression models developed for selected sites on the Animas and San Juan Rivers show that flow, turbidity and specific conductance may be useful in understanding the relationship between total metal concentrations and real-time parameters. Surrogates for suspended sediment such as hydroacoustic may also be useful, and potentially the best option in this system, for monitoring the concentration of metals in surface water. Further evaluation of the chemistry of the watershed soils and bedrock, the streambed sediments, and suspended sediments will improve understanding of the geochemical processes in the Animas and San Juan Rivers.

  17. Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Middle San Luis Rey River, San Diego, southern California—2016 data summary

    Science.gov (United States)

    Allen, Lisa D.; Howell, Scarlett L.; Kus, Barbara E.

    2017-09-29

    Executive SummaryWe surveyed for Least Bell’s Vireos (LBVI) (Vireo bellii pusillus) and Southwestern Willow Flycatchers (SWFL) (Empidonax traillii extimus) along the San Luis Rey River, between College Boulevard in Oceanside and Interstate 15 in Fallbrook, California (middle San Luis Rey River), in 2016. Surveys were done from March 30 to July 11 (LBVI) and from May 18 to July 30 (SWFL). We found 142 LBVI territories, at least 106 of which were occupied by pairs. Six additional transient LBVIs were detected. Of 20 banded LBVIs detected in the survey area, 9 had been given full color-band combinations prior to 2016, although we were unable to determine the exact color combination of 1 female LBVI. Seven other LBVIs with single (natal) federal bands were recaptured and banded in 2016. Four vireos with single dark blue federal bands indicating that they were banded as nestlings on the lower San Luis Rey River could not be recaptured for identification.Three SFWL territories were observed in the survey area in 2016. Two territories were occupied by pairs and one by a male of unknown breeding status. Both pairs attempted to nest at least once, and both pairs were successful, fledging three young each. Nesting began in early June and continued into July. Brown-Headed Cowbird (Molothrus ater) eggs were not observed in either nest. An additional 12 transient Willow Flycatchers of unknown subspecies were detected in 2016.Two of the five resident SWFLs were originally banded as nestlings on Marine Corps Base Camp Pendleton. One male and one female were banded as nestlings on Camp Pendleton in 2009 and 2011, respectively. One natal male of unknown breeding status, originally banded as a nestling on the middle San Luis Rey River in 2015, was recaptured and given a unique color combination in 2016. This male was later detected on Marine Corps Base Camp Pendleton.

  18. Assessing Hydrologic Impacts of Future Land Cover Change Scenarios in the South Platte River Basin (CO, WY, & NE) and the San Pedro River Basin (U.S./Mexico).

    Science.gov (United States)

    Barlow, J. E.; Burns, I. S.; Guertin, D. P.; Kepner, W. G.; Goodrich, D. C.

    2016-12-01

    Long-term land-use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology to characterize hydrologic impacts from future urban growth through time that was developed and applied on the San Pedro River Basin was expanded and utilized on the South Platte River Basin as well. Future urban growth is represented by housing density maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land-Use Scenarios (ICLUS) project. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize hydrologic impacts from future growth, the housing density maps were reclassified to National Land Cover Database (NLCD) 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The objectives of this project were to 1) develop and implement a methodology for adapting the ICLUS data for use in AGWA as an approach to evaluate impacts of development on water-quantity and -quality, 2) present, evaluate, and compare results from scenarios for watersheds in two different geographic and climatic regions, 3) determine watershed specific implications of this type of future land cover change analysis.

  19. Emerging pollutants in the Esmeraldas watershed in Ecuador: discharge and attenuation of emerging organic pollutants along the San Pedro– Guayllabamba–Esmeraldas rivers

    OpenAIRE

    Voloshenko-Rossin, A.; Gasser, G.; Cohen, K.; Gun, J.; Cumbal-Flores, L.; Parra- Morales, W.; Sarabia, F.; Ojeda, F.; Lev, O.

    2015-01-01

    Water quality characteristics and emerging organic pollutants were sampled along the San Pedro–Guayllabamba–Esmeraldas River and its main water pollution streams in the summer of 2013. The annual flow rate of the stream is 22 000 Mm3 y 1 and it collects the wastewater of Quito-Ecuador in the Andes and supplies drinking water to the city of Esmeraldas near the Pacific Ocean. The most persistent emerging pollutants were carbamazepine and acesulfame, which were found to be stable along the San ...

  20. Dissolved Oxygen (DO) and Nutrients Analysis in the Río Piedras River, San Juan, Puerto Rico

    Science.gov (United States)

    Santiago, I.; Infante, G.

    2016-02-01

    The Río Piedras is the only River in the metropolitan area of Puerto Rico. This River was the first water supplier and is part of the ancient aqueduct, the first treatment plant of the San Juan urban area. Because of its cultural and historic importance the ancient aqueduct was cataloged as a National Treasure by the National Trust of History Preservation in 2014. Actually, is protected by Para La Naturaleza (before named in Spanish as the "Fideicomiso de Conservación de Puerto Rico"). The research objectives were to evaluate and measure the dissolved oxygen (DO), total phosphorus (TP) and the heavy metals (HM) concentrations of the River. Also, to examine if the DO, TP and HM (Cu, Fe, Pb, Mn, Al, and Zn) concentrations were in compliance with the Environmental Protection Agency (EPA) standards. Using DO bottles, water samples were collected on three points during six dates. DO concentrations were measured with the YSI Pro GBOD. TP concentrations were analyzed using the UV-Vis spectrophotometer "HACH" (DR 5000). Utilizing the ICP (Inductively Coupled Plasma) spectrophotometer emission technique and the EPA protocols HM concentrations were measured. Preliminary results show that the DO measurements were from 5.00 mg/L to 7.00 mg/L (p-value=0.282). HM concentrations findings were 0.456 (correlation coefficient=0.9997), 1.205 (correlation coefficient=0.9972) and 3.287 (correlation coefficient=0.9950) for Zn, Cu and Cr, respectively. We expected highest HM concentrations in our finals results due to the drought weather during each samples collection. Data analysis for DO, TP and HM concentrations will be presented. Finally, the results obtained and the project details will be explained during the poster presentation.

  1. Development of a shared vision for groundwater management to protect and sustain baseflows of the Upper San Pedro River, Arizona, USA

    Science.gov (United States)

    Richter, Holly E.; Gungle, Bruce; Lacher, Laurel J.; Turner, Dale S.; Bushman, Brooke M.

    2014-01-01

    Groundwater pumping along portions of the binational San Pedro River has depleted aquifer storage that supports baseflow in the San Pedro River. A consortium of 23 agencies, business interests, and non-governmental organizations pooled their collective resources to develop the scientific understanding and technical tools required to optimize the management of this complex, interconnected groundwater-surface water system. A paradigm shift occurred as stakeholders first collaboratively developed, and then later applied, several key hydrologic simulation and monitoring tools. Water resources planning and management transitioned from a traditional water budget-based approach to a more strategic and spatially-explicit optimization process. After groundwater modeling results suggested that strategic near-stream recharge could reasonably sustain baseflows at or above 2003 levels until the year 2100, even in the presence of continued groundwater development, a group of collaborators worked for four years to acquire 2250 hectares of land in key locations along 34 kilometers of the river specifically for this purpose. These actions reflect an evolved common vision that considers the multiple water demands of both humans and the riparian ecosystem associated with the San Pedro River.

  2. Development of a Shared Vision for Groundwater Management to Protect and Sustain Baseflows of the Upper San Pedro River, Arizona, USA

    Directory of Open Access Journals (Sweden)

    Holly E. Richter

    2014-08-01

    Full Text Available Groundwater pumping along portions of the binational San Pedro River has depleted aquifer storage that supports baseflow in the San Pedro River. A consortium of 23 agencies, business interests, and non-governmental organizations pooled their collective resources to develop the scientific understanding and technical tools required to optimize the management of this complex, interconnected groundwater-surface water system. A paradigm shift occurred as stakeholders first collaboratively developed, and then later applied, several key hydrologic simulation and monitoring tools. Water resources planning and management transitioned from a traditional water budget-based approach to a more strategic and spatially-explicit optimization process. After groundwater modeling results suggested that strategic near-stream recharge could reasonably sustain baseflows at or above 2003 levels until the year 2100, even in the presence of continued groundwater development, a group of collaborators worked for four years to acquire 2250 hectares of land in key locations along 34 kilometers of the river specifically for this purpose. These actions reflect an evolved common vision that considers the multiple water demands of both humans and the riparian ecosystem associated with the San Pedro River.

  3. Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-66

    Science.gov (United States)

    Porterfield, George

    1980-01-01

    A review of historical sedimentation data is presented, results of sediment-data collection for water years 1957-59 are summarized, and long-term sediment-discharge estimates from a preliminary report are updated. Comparison of results based on 3 years of data to those for the 10 water years, 1957-66, provides an indication of the adequacy of the data obtained during the short period to define the long-term relation between sediment transport and streamflow. During 1909-66, sediment was transported to the entire San Francisco Bay system at an average rate of 8.6 million cubic yards per year. The Sacramento and San Joaquin River basins provided about 83% of the sediment inflow to the system annually during 1957-66 and 86% during 1909-66. About 98% of this inflow was measured or estimated at sediment measuring sites. Measured sediment inflow directly to the bays comprised only about 40% of the total discharged by basins directly tributary to the bays. About 90% of the total sediment discharge to the delta and the bays in the San Francisco Bay system thus was determined on the basis of systematic measurements. (USGS)

  4. Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico)

    Science.gov (United States)

    Rentería-Villalobos, Marusia; Cortés, Manuel Reyes; Mantero, Juan; Manjón, Guillermo; García-Tenorio, Rafael; Herrera, Eduardo; Montero-Cabrera, Maria Elena

    2012-01-01

    The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work. PMID:22536148

  5. Geochemistry of uranium in ground waters of the Conlara river Valley, San Luis and Cordoba provinces (Argentina)

    International Nuclear Information System (INIS)

    Nicolli, H.B.; Gamba, M.A.

    1979-01-01

    Geochemical characteristics of ground waters related with lixiviation, transport and precipitation of uranium in the Conlara river valley (provinces of San Luis and Cordoba (Argentina)) are studied. Anions and cations' distributions, together with hardness, specific conductivity, pH, Eh, and uranium and vanadium contents, have been studied. Those parameters characterize four hidrogeochemical facies along an E-W profile: a calcic strong bicarbonate facies, an alkaline-calcic bicarbonate facies, an alkaline sulfate facies, and a strong alkaline sulfate facies. An ''Interphase zone'' (transition from bicarbonate water to sulfate water), where changes in composition may define a geochemical environment capable of UO2 precipitation, has been determined. The chemical-Thermodynamic studies give a dominance of UDC and UTC complexs ions (even in sulfate waters), so they represent the 99% of present ions. Besides, the calculated values required for equilibrium with uraninite or carnotite resulted much greater than those obtained in the performed experiments. It means that the precipitation of those minerals requires either the presence of greate amounts of uranium or vanadium, or a reducing environment with Eh values smaller than the observed ones. Finally, the steps to be taken in future investigations are suggested in view to a drilling plan where: 1) Priority to the ''Interphase zone'' areas is given. 2) The deepest aquifers in Tertiary sediments of the basin have to be reached in order to get the convenient environmental conditions (i.e. smallest Eh values) for uranium or uranium-vanadium precipitation. (author) [es

  6. Assessing hydrologic impacts of future Land Change scenarios in the San Pedro River (U.S./Mexico)

    Science.gov (United States)

    Kepner, W. G.; Burns, S.; Sidman, G.; Levick, L.; Goodrich, D. C.; Guertin, P.; Yee, W.; Scianni, M.

    2012-12-01

    An approach was developed to characterize the hydrologic impacts of urban expansion through time for the San Pedro River, a watershed of immense international importance that straddles the U.S./Mexico border. Future urban growth is a key driving force altering local and regional hydrology and is represented by decadal changes in housing density maps from 2010 to 2100 derived from the Integrated Climate and Land-Use Scenarios (ICLUS) database. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize the hydrologic impacts of future growth, the housing density maps were reclassified to National Land Cover Database 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The presentation will report 1) the methodology for adapting the ICLUS data for use in AGWA as an approach to evaluate basin-wide impacts of development on water-quantity and -quality, 2) initial results of the application of the methodology, and 3) discuss implications of the analysis.

  7. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    Science.gov (United States)

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  8. Ecosystem services valuation to support decisionmaking on public lands—A case study of the San Pedro River watershed, Arizona

    Science.gov (United States)

    Bagstad, Kenneth J.; Semmens, Darius; Winthrop, Rob; Jaworksi, Delilah; Larson, Joel

    2012-01-01

    This report details the findings of the Bureau of Land Management–U.S. Geological Survey Ecosystem Services Valuation Pilot Study. This project evaluated alternative methods and tools that quantify and value ecosystem services, and it assessed the tools’ readiness for use in the Bureau of Land Management decisionmaking process. We tested these tools on the San Pedro River watershed in northern Sonora, Mexico, and southeast Arizona. The study area includes the San Pedro Riparian National Conservation Area (managed by the Bureau of Land Management), which has been a focal point for conservation activities and scientific research in recent decades. We applied past site-specific primary valuation studies, value transfer, the Wildlife Habitat Benefits Estimation Toolkit, and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and Artificial Intelligence for Ecosystem Services (ARIES) models to value locally important ecosystem services for the San Pedro River watershed—water, carbon, biodiversity, and cultural values. We tested these approaches on a series of scenarios to evaluate ecosystem service changes and the ability of the tools to accommodate scenarios. A suite of additional tools were either at too early a stage of development to run, were proprietary, or were place-specific tools inappropriate for application to the San Pedro River watershed. We described the strengths and weaknesses of these additional ecosystem service tools against a series of evaluative criteria related to their usefulness for Bureau of Land Management decisionmaking. Using these tools, we quantified gains or losses of ecosystem services under three categories of scenarios: urban growth, mesquite management, and water augmentation. These results quantify tradeoffs and could be useful for decisionmaking within Bureau of Land Management district or field offices. Results are accompanied by a relatively high level of uncertainty associated with model outputs, valuation

  9. Joaquin Inigo-Golfin (1965-2011)

    CERN Multimedia

    2011-01-01

    It is with immense sadness that we learned that Joaquin INIGO-GOLFIN passed away last week; until the very end we hoped that he would win the battle he so heroically fought. Joaquin was a very special person who left no one indifferent. His professional skills, warmth and openness were matched with a sense of humor that made him a friend and colleague “à part”.   Joaquin joined CERN in August 1992 to work in the Cooling and Ventilation Group where he spent almost all his professional career covering many disciplines and responsibilities: operations, installation and design. He was also responsible for the introduction of new technologies to CV, such as Computer Aided Design, and for the evaluation and adoption of Computational Fluid Dynamics, particularly for the analysis of complex thermal systems. The remarkable results Joaquin achieved through his work and strong technical competence made him the natural candidate to lead the design section responsible for all th...

  10. Aplicación de tres índices bióticos en el río San Juan, Andes, Colombia (Application of three biotic indexes in the river San Juan, Andes, Colombia

    Directory of Open Access Journals (Sweden)

    Mailedt Paola Murillo Torrentes

    2016-09-01

    Full Text Available Durante los meses de febrero, mayo, agosto y octubre del año 2014, se evaluó la calidad del agua del río San Juan. Para tal fin se establecieron seis puntos de muestreo donde se recolectaron muestras de agua y macroinvertebrados acuáticos para los análisis fisicoquímicos e hidrobiológicos. Se aplicaron y modificaron los índices bióticos EPT (efemerópteros, plecópteros, tricópteros, BMWP/Col (Biological Monitoring Working Party y ASPT (Average Score per Taxon basados en las comunidades de macroinvertebrados acuáticos capturados. Los resultados de las variables fisicoquímicas y los índices bióticos indican que las estaciones E1 y E2 son las que presentan menor grado de contaminación, en las demás estaciones disminuye considerablemente la calidad del agua debido a las actividades económicas desarrolladas en el sector y a su cercanías con el casco urbano del municipio de Andes. De los tres índices analizados, el ASPT modificado y adaptado al río San Juan es el que mejor se relaciona con las condiciones ambientales del río en tanto las características de los macroinvertebrados acuáticos recolectados y analizados en el trayecto objeto de estudio. (Abstract. During the months of February, May, August and October 2014, the water quality of the San Juan River was assessed. To this aim, six sampling points were established, where water samples and macroinvertebrates for physical-chemical and hydrobiological analysis were collected. Three biotic indexes were applied and one modified: EPT (Ephemeroptera, Plecoptera, Trichoptera, BMWP / Col (Biological Monitoring Working Party and ASPT (Average Score per Taxon based on the captured communities of aquatic macroinvertebrates. The results of the physical-chemical variables and biotic indixes indicate that E1 and E2 stations are those with lower degree of contamination, other stations considerably decreased water quality due to economic activities around, and the short distance with the

  11. Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  12. Projected evolution of California's San Francisco bay-delta-river system in a century of climate change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel R.; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; Van der Wegen, Mick; Wagner, R.W.; Jassby, Alan D.

    2011-01-01

    Background: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings: We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance: Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  13. Analysis of past and future dam formation and failure in the Santa Cruz River (San Juan province, Argentina)

    Science.gov (United States)

    Penna, Ivanna M.; Derron, Marc-Henri; Volpi, Michele; Jaboyedoff, Michel

    2013-03-01

    Around 11.5 ∗ 106 m3 of rock detached from the eastern slope of the Santa Cruz valley (San Juan province, Argentina) in the first fortnight of January 2005. The rockslide-debris avalanche blocked the course, resulting in the development of a lake with maximum length of around 3.5 km. The increase in the inflow rate from 47,000-74,000 m3/d between April and October to 304,000 m3/d between late October and the first fortnight of November, accelerated the growing rate of the lake. On 12 November 2005 the dam failed, releasing 24.6 ∗ 106 m3 of water. The resulting outburst flood caused damages mainly on infrastructure, and affected the facilities of a hydropower dam which was under construction 250 km downstream from the source area. In this work we describe causes and consequences of the natural dam formation and failure, and we dynamically model the 2005 rockslide-debris avalanche with DAN3D. Additionally, as a volume ~ 24 ∗ 106 m3of rocks still remain unstable in the slope, we use the results of the back analysis to forecast the formation of a future natural dam. We analyzed two potential scenarios: a partial slope failure of 6.5 ∗ 106 m3 and a worst case where all the unstable volume remaining in the slope fails. The spreading of those potential events shows that a new blockage of the Santa Cruz River is likely to occur. According to their modeled morphometry and the contributing watershed upstream the blockage area, as the one of 2005, the dams would also be unstable. This study shows the importance of back and forward analysis that can be carried out to obtain critical information for land use planning, hazards mitigation, and emergency management.

  14. Algal and Cyanobacterial communities in two rivers of the province of San Luis (Argentina subjected to anthropogenic influence

    Directory of Open Access Journals (Sweden)

    Jorgelina Daruich

    2013-03-01

    Full Text Available AIM: The use of biological indicators of pollution has increased in recent years as an alternative to the monitoring of water quality. Phytoplankton community selectively respond to different anthropogenic disturbances, such as water dams and the increase of nutrients coming from city centers, which leads to the eutrophication of the aquatic environment. The objective of this work was to evaluate the composition and the structure of the algal and Cyanobacterial communities in order to prove human influences by the presence of reservoirs with some degree of eutrophication and the impact of urbanization in two rivers at the Bebedero basin in San Luis province (Argentine. METHODS: Four sites were sampled: two of them were placed before dams and villages (V1 and (P1 and two after them (V2 and (P2. Each site was visited in every season of the year: summer, autumn, winter and spring. Qualitative and semi-quantitative phytoplankton samples were taken, and the frequency of occurrence was determined. Variations between pairs of sampling stations were analyzed through the Jaccard similarity and complementarity indices. RESULTS: Ninety two taxa were identified, of which diatoms were the most frequent. The most affected station was P2 with high abundance, less diversity and equitability, whereas the species more tolerant to the presence of organic matter were Melosira varians, Navicula tripunctata, Oscillatoria limosa, Gomphonema parvulum and Coelastrum microporum, and some species of euglenophytas. CONCLUSION: Therefore, the structure and composition of the algal and Cyanobacterial communities allowed us to identify sections more sensitive to human-induced alterations.

  15. Projected evolution of California's San Francisco Bay-Delta-river system in a century of climate change.

    Directory of Open Access Journals (Sweden)

    James E Cloern

    Full Text Available Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species.We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations.Most of these environmental indicators change substantially over the 21(st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1 an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2 varying sensitivity among environmental indicators to the uncertainty of future climates; (3 inevitability of biological community changes as responses to cumulative effects of climate

  16. Projected Evolution of California's San Francisco Bay-Delta-River System in a Century of Climate Change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  17. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, SAN JOAQUIN COUNTY, CALIFORNIA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk...

  18. San Francisco Bay nutrients and plankton dynamics as simulated by a coupled hydrodynamic-ecosystem model

    Science.gov (United States)

    Liu, Qianqian; Chai, Fei; Dugdale, Richard; Chao, Yi; Xue, Huijie; Rao, Shivanesh; Wilkerson, Frances; Farrara, John; Zhang, Hongchun; Wang, Zhengui; Zhang, Yinglong

    2018-06-01

    An open source coupled physical-biogeochemical model is developed for San Francisco Bay (SFB) to study nutrient cycling and plankton dynamics as well as to assist ecosystem based management and risk assessment. The biogeochemical model in this study is based on the Carbon, Silicate and Nitrogen Ecosystem (CoSiNE) model, and coupled to the unstructured grid, Semi-Implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The SCHISM-CoSiNE model reproduces the spatial and temporal variability in nutrients and plankton biomass, and its physical and biogeochemical performance is successfully tested using comparisons with shipboard and fixed station observations. The biogeochemical characteristics of the SFB during wet and dry years are investigated by changing the input of the major rivers. River discharges from the Sacramento and San Joaquin Rivers affect the phytoplankton biomass in North SFB through both advection and dilution of nutrient (including ammonium, NH4) concentrations in the river. The reduction in residence time caused by increased inflows can result in decreased biomass accumulation, while the corresponding reduction in NH4 concentration favors the growth of biomass. In addition, the model is used to make a series of sensitivity experiments to examine the response of SFB to changes in 1) nutrient loading from rivers and wastewater treatment plants (WWTPs), 2) a parameter (ψ) defining NH4 inhibition of nitrate (NO3) uptake by phytoplankton, 3) bottom grazing and 4) suspended sediment concentration. The model results show that changes in NH4 input from rivers or WWTPs affect the likelihood of phytoplankton blooms via NH4 inhibition and that the choice of ψ is critical. Bottom grazing simulated here as increased plankton mortality demonstrates the potential for bivalve reduction of chlorophyll biomass and the need to include bivalve grazing in future models. Furthermore, the model demonstrates the need to include sediments and their contribution

  19. Fine-Resolution Modeling of the Santa Cruz and San Pedro River Basins for Climate Change and Riparian System Studies

    Science.gov (United States)

    Robles-Morua, A.; Vivoni, E. R.; Volo, T. J.; Rivera, E. R.; Dominguez, F.; Meixner, T.

    2011-12-01

    This project is part of a multidisciplinary effort aimed at understanding the impacts of climate variability and change on the ecological services provided by riparian ecosystems in semiarid watersheds of the southwestern United States. Valuing the environmental and recreational services provided by these ecosystems in the future requires a numerical simulation approach to estimate streamflow in ungauged tributaries as well as diffuse and direct recharge to groundwater basins. In this work, we utilize a distributed hydrologic model known as the TIN-based Real-time Integrated Basin Simulator (tRIBS) in the upper Santa Cruz and San Pedro basins with the goal of generating simulated hydrological fields that will be coupled to a riparian groundwater model. With the distributed model, we will evaluate a set of climate change and population scenarios to quantify future conditions in these two river systems and their impacts on flood peaks, recharge events and low flows. Here, we present a model confidence building exercise based on high performance computing (HPC) runs of the tRIBS model in both basins during the period of 1990-2000. Distributed model simulations utilize best-available data across the US-Mexico border on topography, land cover and soils obtained from analysis of remotely-sensed imagery and government databases. Meteorological forcing over the historical period is obtained from a combination of sparse ground networks and weather radar rainfall estimates. We then focus on a comparison between simulation runs using ground-based forcing to cases where the Weather Research Forecast (WRF) model is used to specify the historical conditions. Two spatial resolutions are considered from the WRF model fields - a coarse (35-km) and a downscaled (10- km) forcing. Comparisons will focus on the distribution of precipitation, soil moisture, runoff generation and recharge and assess the value of the WRF coarse and downscaled products. These results provide confidence in

  20. Regional scale flood modeling using NEXRAD rainfall, GIS, and HEC-HMS/RAS: a case study for the San Antonio River Basin Summer 2002 storm event.

    Science.gov (United States)

    Knebl, M R; Yang, Z-L; Hutchison, K; Maidment, D R

    2005-06-01

    This paper develops a framework for regional scale flood modeling that integrates NEXRAD Level III rainfall, GIS, and a hydrological model (HEC-HMS/RAS). The San Antonio River Basin (about 4000 square miles, 10,000 km2) in Central Texas, USA, is the domain of the study because it is a region subject to frequent occurrences of severe flash flooding. A major flood in the summer of 2002 is chosen as a case to examine the modeling framework. The model consists of a rainfall-runoff model (HEC-HMS) that converts precipitation excess to overland flow and channel runoff, as well as a hydraulic model (HEC-RAS) that models unsteady state flow through the river channel network based on the HEC-HMS-derived hydrographs. HEC-HMS is run on a 4 x 4 km grid in the domain, a resolution consistent with the resolution of NEXRAD rainfall taken from the local river authority. Watershed parameters are calibrated manually to produce a good simulation of discharge at 12 subbasins. With the calibrated discharge, HEC-RAS is capable of producing floodplain polygons that are comparable to the satellite imagery. The modeling framework presented in this study incorporates a portion of the recently developed GIS tool named Map to Map that has been created on a local scale and extends it to a regional scale. The results of this research will benefit future modeling efforts by providing a tool for hydrological forecasts of flooding on a regional scale. While designed for the San Antonio River Basin, this regional scale model may be used as a prototype for model applications in other areas of the country.

  1. Rainfall-runoff characteristics and effects of increased urban density on streamflow and infiltration in the eastern part of the San Jacinto River basin, Riverside County, California

    Science.gov (United States)

    Guay, Joel R.

    2002-01-01

    To better understand the rainfall-runoff characteristics of the eastern part of the San Jacinto River Basin and to estimate the effects of increased urbanization on streamflow, channel infiltration, and land-surface infiltration, a long-term (1950?98) time series of monthly flows in and out of the channels and land surfaces were simulated using the Hydrologic Simulation Program- FORTRAN (HSPF) rainfall-runoff model. Channel and land-surface infiltration includes rainfall or runoff that infiltrates past the zone of evapotranspiration and may become ground-water recharge. The study area encompasses about 256 square miles of the San Jacinto River drainage basin in Riverside County, California. Daily streamflow (for periods with available data between 1950 and 1998), and daily rainfall and evaporation (1950?98) data; monthly reservoir storage data (1961?98); and estimated mean annual reservoir inflow data (for 1974 conditions) were used to calibrate the rainfall-runoff model. Measured and simulated mean annual streamflows for the San Jacinto River near San Jacinto streamflow-gaging station (North-South Fork subbasin) for 1950?91 and 1997?98 were 14,000 and 14,200 acre-feet, respectively, a difference of 1.4 percent. The standard error of the mean for measured and simulated annual streamflow in the North-South Fork subbasin was 3,520 and 3,160 acre-feet, respectively. Measured and simulated mean annual streamflows for the Bautista Creek streamflow-gaging station (Bautista Creek subbasin) for 1950?98 were 980 acre-feet and 991 acre-feet, respectively, a difference of 1.1 percent. The standard error of the mean for measured and simulated annual streamflow in the Bautista Creek subbasin was 299 and 217 acre-feet, respectively. Measured and simulated annual streamflows for the San Jacinto River above State Street near San Jacinto streamflow-gaging station (Poppet subbasin) for 1998 were 23,400 and 23,500 acre-feet, respectively, a difference of 0.4 percent. The simulated

  2. A Tree-Ring Reconstruction of the Salinity Gradient in the Northern Estuary of San Francisco Bay

    Directory of Open Access Journals (Sweden)

    David W. Stahle

    2011-04-01

    Full Text Available Blue oak tree-ring chronologies correlate highly with winter–spring precipitation totals over California, with Sacramento and San Joaquin river stream flow, and with seasonal variations in the salinity gradient in San Francisco Bay. The convergence of fresh and saline currents can influence turbidity, sediment accumulation, and biological productivity in the estuary. Three selected blue oak chronologies were used to develop a 625-year-long reconstruction of the seasonal salinity gradient, or low salinity zone (LSZ, which provides a unique perspective on the interannual-to-decadal variability of this important estuarine habitat indicator. The reconstruction was calibrated with instrumental LSZ data for the winter–spring season, and explains 73% of the variance in the February–June position of the LSZ from 1956 to 2003. Because this calibration period post-dates the sweeping changes that have occurred to land cover, channel morphology, and natural streamflow regimes in California, the reconstruction provides an idealized estimate for how the LSZ might have fluctuated under the seasonal precipitation variations of the past 625 years, given the modern geometry and bathymetry of the estuary and land cover across the drainage basin. The February–June season integrates precipitation and runoff variability during the cool season, and does not extend into the late-summer dry season when LSZ extremes can negatively affect Sacramento–San Joaquin Delta (Delta agriculture and some aquatic organisms. However, there is such strong inter-seasonal persistence in the instrumental LSZ data that precipitation totals during the cool season can strongly pre-condition LSZ position in late summer. The 625-year-long reconstruction indicates strong interannual and decadal variability, the frequent recurrence of consecutive 2-year LSZ maxima and minima, large-scale ocean atmospheric forcing, and an interesting asymmetrical influence of warm El Ni

  3. Emerging pollutants in the Esmeraldas watershed in Ecuador: discharge and attenuation of emerging organic pollutants along the San Pedro-Guayllabamba-Esmeraldas rivers.

    Science.gov (United States)

    Voloshenko-Rossin, A; Gasser, G; Cohen, K; Gun, J; Cumbal-Flores, L; Parra-Morales, W; Sarabia, F; Ojeda, F; Lev, O

    2015-01-01

    Water quality characteristics and emerging organic pollutants were sampled along the San Pedro-Guayllabamba-Esmeraldas River and its main water pollution streams in the summer of 2013. The annual flow rate of the stream is 22 000 Mm(3) y(-1) and it collects the wastewater of Quito-Ecuador in the Andes and supplies drinking water to the city of Esmeraldas near the Pacific Ocean. The most persistent emerging pollutants were carbamazepine and acesulfame, which were found to be stable along the San Pedro-Guayllabamba-Esmeraldas River, whereas the concentration of most other organic emerging pollutants, such as caffeine, sulfamethoxazole, venlafaxine, O-desmethylvenlafaxine, and steroidal estrogens, was degraded to a large extent along the 300 km flow. The mass rate of the sum of cocaine and benzoylecgonine, its metabolite, was increased along the stream, which may be attributed to coca plantations and wild coca trees. This raises the possibility of using river monitoring as an indirect way to learn about changes in coca plantations in their watersheds. Several organic emerging pollutants, such as venlafaxine, carbamazepine, sulphamethoxazole, and benzoylecgonine, survived even the filtration treatment at the Esmeraldas drinking water system, though all except for benzoylecgonine are found below 20 ng L(-1), and are therefore not likely to cause adverse health effects. The research provides a way to compare drug consumption in a major Latin American city (Quito) and shows that the consumption of most sampled drugs (carbamazepine, venlafaxine, O-desmethylvenlafaxine, sulphamethoxazole, ethinylestradiol) was below their average consumption level in Europe, Israel, and North America.

  4. Presence of multi-drug resistant pathogenic Escherichia coli in the San Pedro River located in the State of Aguascalientes, Mexico.

    Directory of Open Access Journals (Sweden)

    Flor Yazmin Ramirez Castillo

    2013-06-01

    Full Text Available Contamination of surface waters in developing countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks and may represent a significant dissemination mechanism of antibiotic resistance genes. In this study, the water quality of San Pedro River, the main river and pluvial collector of the Aguascalientes State, Mexico was assessed. Thirty sample locations were tested throughout the River. The main physicochemical parameters of water were evaluated. Results showed high levels of fecal pollution as well as inorganic and organic matter abundant enough to support the heterotrophic growth of microorganisms. These results indicate poor water quality in samples from different locations. One hundred and fifty Escherichia coli were collected and screened by PCR for several virulence genes. Isolates were classified as either pathogenic (n = 91 or commensal (n = 59. The disc diffusion method was used to determine antimicrobial susceptibility to 13 antibiotics. Fifty-two percent of the isolates were resistant to at least one antimicrobial agent and 30.6% were multi-resistant. Eighteen E. coli strains were quinolone resistant of which 16 were multi-resistant. Plasmid-mediated quinolone resistance genes were detected in 12 isolates. Mutations at the Ser-83→Leu and/or Asp-87→Asn in the gyrA gene were detected as well as mutations at the Ser-80→Ile in parC. An E. coli microarray (Maxivirulence V 3.1 was used to characterize the virulence and antimicrobial resistance genes profiles of the fluoroquinolone-resistant isolates. Antimicrobial resistance genes such as blaTEM, sulI, sulII, dhfrIX, aph3 (strA and tet (B as well as integrons were found in fluoroquinolone resistance E. coli strains. The presence of potential pathogenic E. coli and antibiotic resistance in San Pedro River such as fluoroquinolone resistant E. coli could pose a potential threat to human

  5. Content of heavy metals in the sediments of the rivers and adjacent gullies to Relleno de Rio Azul, Rio Azul, San Jose, Costa Rica

    International Nuclear Information System (INIS)

    Mora Amador, R.A.

    2003-01-01

    In Costa Rica it is not had studies that have documented heavy the fluvial sediment metal concentrations, caused by point sources of polluting agents, as they are the sites of I deposit of been accustomed to remainders. The potential source of heavy metal concentrations in the study area, it is an active sanitary filling, known like Sanitary Landing Azul River, which is located to the Southeastern of the city of San Jose, in the District of Azul River, Corner of the Union. The site where this made up of a sequence of materials of volcanic origin is located to the filling of Azul River, which could be affected by local fault, this fact would mean a serious threat of contamination of underground waters of the region, then the geological faults constitute very permeable means, able to put in contact the polluting agents of the water-bearing filling with some. The mass of metals deposited in the site, from 1978 to date, metric ton has calculated between 70000 to 100000, which turns it an environmental preoccupation of first order. The results of x-rays fluorescence show the presence of elements like vanadium, chromium, manganese, it receives, zinc rubidium, strontium, potassium, calcium, iron, titanium and yttrium, which show a tendency to present/display high concentrations but in the fine fraction (d [es

  6. Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

    Science.gov (United States)

    Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.

    2005-01-01

    Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production. ?? 2005 Estuarine Research Federation.

  7. Morphotectonic and neotectonic control on river pattern in the Sierra de la Cantera piedmont, Central Precordillera, province of San Juan, Argentina

    Science.gov (United States)

    Perucca, Laura P.; Rothis, Martín; Vargas, Horacio N.

    2014-01-01

    The drainage pattern on the western piedmont of the Sierra de La Cantera is divergent, typical of alluvial fans and showing anomalies that are directly related to the trace of La Cantera thrust. In previous studies, two types of anomalies were identified: upstream of the fault scarp, rivers have a broom-shaped pattern, while downstream - in the hanging block - streams become denser, more sinuous and incised. In this contribution, these morphotectonic aspects were analyzed in detail, making direct and indirect analysis to quantify the relationship between these anomalies and the faults affecting alluvial fans. In addition, the influence of neotectonic activity on smaller water course patterns in the alluvial fan areas was investigated in order to find indicators of on-going vertical movements, since the spatial arrangements of these piedmont channels are determined by slope and structure, where active faults cause diversions or anomalies. Topographic profiles in two selected channels cutting across the trace of the fault were performed using a differential GPS in order to establish the relationship between the sinuosity and slope of these rivers. The results obtained allow us to state that the most sinuous channels have lower slopes and are located in the hanging wall of the fault. Morphometric analysis of scarps stated that active tectonics have played an essential role in controlling the drainage pattern in the piedmont, leading the rivers to adjust to these slope variations. Finally, based on the geomorphologic, stratigraphic, structural and seismological characteristics and parameters analyzed, La Cantera Thrust is considered a seismogenic source of significance to the nearby towns (> 700,000 inhabitants) and also to the large-scale dams built downstream along the San Juan River.

  8. Ferricrete, manganocrete, and bog iron occurrences with selected sedge bogs and active iron bogs and springs in the upper Animas River watershed, San Juan County, Colorado

    Science.gov (United States)

    Yager, Douglas B.; Church, Stan E.; Verplanck, Philip L.; Wirt, Laurie

    2003-01-01

    During 1996 to 2000, the Bureau of Land Management, National Park Service, Environmental Protection Agency, United States Department of Agriculture (USDA) Forest Service, and the U.S. Geological Survey (USGS) developed a coordinated strategy to (1) study the environmental effects of historical mining on Federal lands, and (2) remediate contaminated sites that have the greatest impact on water quality and ecosystem health. This dataset provides information that contributes to these overall objectives and is part of the USGS Abandoned Mine Lands Initiative. Data presented here represent ferricrete occurrences and selected iron bogs and springs in the upper Animas River watershed in San Juan County near Silverton, Colorado. Ferricretes (stratified iron and manganese oxyhydroxide-cemented sedimentary deposits) are one indicator of the geochemical baseline conditions as well as the effect that weathering of mineralized rocks had on water quality in the Animas River watershed prior to mining. Logs and wood fragments preserved in several ferricretes in the upper Animas River watershed, collected primarily along streams, yield radiocarbon ages of modern to 9,580 years B.P. (P.L. Verplanck, D.B. Yager, and S.E. Church, work in progress). The presence of ferricrete deposits along the current stream courses indicates that climate and physiography of the Animas River watershed have been relatively constant throughout the Holocene and that weathering processes have been ongoing for thousands of years prior to historical mining activities. Thus, by knowing where ferricrete is preserved in the watershed today, land-management agencies have an indication of (1) where metal precipitation from weathering of altered rocks has occurred in the past, and (2) where this process is ongoing and may confound remediation efforts. These data are included as two coverages-a ferricrete coverage and a bogs and springs coverage. The coverages are included in ArcInfo shapefile and Arc

  9. Riverine based eco-tourism: Trinity River non-market benefits estimates

    Science.gov (United States)

    Douglas, A.J.; Taylor, J.G.

    1998-01-01

    California's Central Valley Project (CVP) was approved by voters in a statewide referendum in 1933. CVP referendum approval initiated funding for construction of important water development projects that had far reaching effects on regional water supplies. The construction of Trinity Dam in 1963 and the subsequent transbasin diversion of Trinity River flow was one of several CVP projects that had noteworthy adverse environmental and regional economic impacts. The Trinity River is the largest tributary of the Klamath River, and has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel. Before 1963, the Trinity River was a major recreation resource of Northern California. The loss of streamflow has had a marked adverse impact on Trinity River-related recreation activities and the size and robustness of Trinity River salmon, steelhead, shad, and sturgeon runs. Trinity River water produces hydropower during its transit via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The benefits provided by Trinity River instream flow-related environmental amenities were estimated with the travel cost method (TCM). Trinity River non-market benefits are about $406 million per annum, while the social cost of sending water down the Trinity River ranges from $17 to $42 million per annum, depending on the exact flow. We also discuss the relative magnitude of Trinity River survey data contingent value method (CVM) benefits estimates.

  10. Quantification and Simulation of Metal Loading to the Upper Animas River, Eureka to Silverton, San Juan County, Colorado, September 1997 and August 1998

    Science.gov (United States)

    Paschke, Suzanne S.; Kimball, Briant A.; Runkel, Robert L.

    2005-01-01

    Drainage from abandoned and inactive mines and from naturally mineralized areas in the San Juan Mountains of southern Colorado contributes metals to the upper Animas River near Silverton, Colorado. Tracer-injection studies and associated synoptic sampling were performed along two reaches of the upper Animas River to develop detailed profiles of stream discharge and to locate and quantify sources of metal loading. One tracer-injection study was performed in September 1997 on the Animas River reach from Howardsville to Silverton, and a second study was performed in August 1998 on the stream reach from Eureka to Howardsville. Drainage in the upper Animas River study reaches contributed aluminum, calcium, copper, iron, magnesium, manganese, sulfate, and zinc to the surface-water system in 1997 and 1998. Colloidal aluminum, dissolved copper, and dissolved zinc were attenuated through a braided stream reach downstream from Eureka. Instream dissolved copper concentrations were lower than the State of Colorado acute and chronic toxicity standards downstream from the braided reach to Silverton. Dissolved iron load and concentrations increased downstream from Howardsville and Arrastra Gulch, and colloidal iron remained constant at low concentrations downstream from Howardsville. Instream sulfate concentrations were lower than the U.S. Environmental Protection Agency's secondary drinking-water standard of 250 milligrams per liter throughout the two study reaches. Elevated zinc concentrations are the primary concern for aquatic life in the upper Animas River. In the 1998 Eureka to Howardsville study, instream dissolved zinc load increased downstream from the Forest Queen mine, the Kittimack tailings, and Howardsville. In the 1997 Howardsville to Silverton study, there were four primary areas where zinc load increased. First, was the increase downstream from Howardsville and abandoned mining sites downstream from the Cunningham Gulch confluence, which also was measured during

  11. Regional and Large-Scale Climate Influences on Tree-Ring Reconstructed Null Zone Position in San Francisco Bay

    Science.gov (United States)

    Stahle, D.; Griffin, D.; Cleaveland, M.; Fye, F.; Meko, D.; Cayan, D.; Dettinger, M.; Redmond, K.

    2007-05-01

    A new network of 36 moisture sensitive tree-ring chronologies has been developed in and near the drainage basins of the Sacramento and San Joaquin Rivers. The network is based entirely on blue oak (Quercus douglasii), which is a California endemic found from the lower forest border up into the mixed conifer zone in the Coast Ranges, Sierra Nevada, and Cascades. These blue oak tree-ring chronologies are highly correlated with winter-spring precipitation totals, Sacramento and San Joaquin streamflow, and with seasonal variations in salinity and null zone position in San Francisco Bay. Null zone is the non-tidal bottom water location where density-driven salinity and river-driven freshwater currents balance (zero flow). It is the area of highest turbidity, water residence time, sediment accumulation, and net primary productivity in the estuary. Null zone position is measured by the distance from the Golden Gate of the 2 per mil bottom water isohaline and is primarily controlled by discharge from the Sacramento and San Joaquin Rivers (and ultimately by winter-spring precipitation). The location of the null zone is an estuarine habitat indicator, a policy variable used for ecosystem management, and can have a major impact on biological resources in the San Francisco estuary. Precipitation-sensitive blue oak chronologies can be used to estimate null zone position based on the strong biogeophysical interaction among terrestrial, aquatic, and estuarine ecosystems, orchestrated by precipitation. The null zone reconstruction is 626-years long and provides a unique long term perspective on the interannual to decadal variability of this important estuarine habitat indicator. Consecutive two-year droughts (or longer) allow the null zone to shrink into the confined upper reaches of Suisun Bay, causing a dramatic reduction in phytoplankton production and favoring colonization of the estuary by marine biota. The reconstruction indicates an approximate 10 year recurrence interval

  12. Stochastic Modeling of Sediment Connectivity for Reconstructing Sand Fluxes and Origins in the Unmonitored Se Kong, Se San, and Sre Pok Tributaries of the Mekong River

    Science.gov (United States)

    Schmitt, R. J. P.; Bizzi, S.; Castelletti, A. F.; Kondolf, G. M.

    2018-01-01

    Sediment supply to rivers, subsequent fluvial transport, and the resulting sediment connectivity on network scales are often sparsely monitored and subject to major uncertainty. We propose to approach that uncertainty by adopting a stochastic method for modeling network sediment connectivity, which we present for the Se Kong, Se San, and Sre Pok (3S) tributaries of the Mekong. We quantify how unknown properties of sand sources translate into uncertainty regarding network connectivity by running the CASCADE (CAtchment Sediment Connectivity And DElivery) modeling framework in a Monte Carlo approach for 7,500 random realizations. Only a small ensemble of realizations reproduces downstream observations of sand transport. This ensemble presents an inverse stochastic approximation of the magnitude and variability of transport capacity, sediment flux, and grain size distribution of the sediment transported in the network (i.e., upscaling point observations to the entire network). The approximated magnitude of sand delivered from each tributary to the Mekong is controlled by reaches of low transport capacity ("bottlenecks"). These bottlenecks limit the ability to predict transport in the upper parts of the catchment through inverse stochastic approximation, a limitation that could be addressed by targeted monitoring upstream of identified bottlenecks. Nonetheless, bottlenecks also allow a clear partitioning of natural sand deliveries from the 3S to the Mekong, with the Se Kong delivering less (1.9 Mt/yr) and coarser (median grain size: 0.4 mm) sand than the Se San (5.3 Mt/yr, 0.22 mm) and Sre Pok (11 Mt/yr, 0.19 mm).

  13. Monitoring the Northern San Francisco Bay Water Quality with Landsat-8. Nicholas B. Tufillaroa , and Curtiss O. Davisa. aOregon State University, Corvallis, OR, 97331, USA, nbt@coas.oregonstate.edu

    Science.gov (United States)

    Davis, C. O.; Tufillaro, N.

    2016-02-01

    Landsat-8's high spatial resolution ( 30 nm nominal), improved signal-to-noise (12bit digitizer) and expanded band set open up new applications for coastal and in-land waters. We use a recent ocean color processor for Landsat-8 created by Vanhellemont and Ruddick (RSE, 2015)to examine changes in the Northern San Francisco Bay, in particular looking for possiblechanges due to the on-going California drought. For instance, a temporary drought barrier to prevent salt water intrusion was placed during May of 2015 at West False River in the Sacramento-San Joaquin Delta. Using the new Landsat-8 ocean color products, we illustrate how to monitor changes in macro algae and plants (Sago pondweed (native), Curly pondweed (non-native)) in regions directly effected,such as the Franks Track region. Product maps using panchromatic enhancement ( 15 m resolution) andscene based atmospheric correction allow a detailed synoptic look every 16 days during theSpring, Summer, and Fall of 2015. This work is part of a larger NASA funded project aimed atimproving the modeling and predictive capabilities of the biogeochemical state for the San Francisco Bay(Davis, PI: Impacts of Population Growth on the San Francisco Bay and Delta Ecosystem, 2014-2017).

  14. Use of dissolved inorganic carbon isotopes to track photosynthesis, respiration, and nitrification along a 56 mile transect in the Sacramento River and San Francisco Bay

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Peek, S.; Young, M. B.

    2013-12-01

    A decline in phytoplankton stocks in the San Francisco Bay and Delta is thought to contribute to the pelagic organism decline observed over the past two decades. One factor controlling phytoplankton growth rate is the availability of nutrients. Although there is an excess of nutrients in the Bay and Delta, the type and relative abundance of nutrients is critical to phytoplankton growth. To evaluate the response of phytoplankton to nutrient sources and to better understand phytoplankton dynamics downstream, we tested the hypothesis that the δ13C values of dissolved inorganic carbon (DIC) along with conventional water chemistry analyses will record events such as increased nitrification (related to the Sacramento River Wastewater Treatment Plant ammonium input) and algal blooms, and reflect the balance between photosynthesis and bacterial respiration. Multiple parameters affect [DIC] and its δ13C, including DIC sources, pH, and biological processes. Consumption of CO2 by phytoplankton during photosynthesis and by autotrophic bacteria during nitrification both result in increases in δ13C-DIC. However, photosynthesis and nitrification have very different relationships to chlorophyll and nutrient concentrations. The balance between heterotrophic bacterial respiration and photosynthesis should be reflected in trends in DIC, nutrient, and chlorophyll concentration, and δ13C-DIC. The δ13C of DIC should also be reflected in the δ13C of phytoplankton with approximately a 20 per mil fractionation. Significant deviation in the fractionation factor may indicate local variations in growth rate, nutrient availability, or speciation. Combined, these parameters should provide a gauge of the relative importance of the above mentioned processes. To test this hypothesis, we collected 19 water samples per cruise between July 2012 and July 2013 along a 56 mile transect between Rio Vista on the Sacramento River and San Francisco Bay near Angel Island during 8 cruises on the USGS RV

  15. Heavy metal contents in sediments of rivers and adjacent streams to the filling of Rio Azul, Rio Azul, San Jose, Costa Rica

    International Nuclear Information System (INIS)

    Mora Amador, Raul Alberto

    2003-01-01

    In Costa Rica there are no studies that have documented the concentrations of heavy metals in river sediments, caused by point sources of pollutants, such as the deposits sites of solid waste. The potential source of heavy metals concentrations in the study area, is an active landfill, known as Relleno Sanitario de Rio Azul, which is located southeast of the city of San Jose, in Distrito de Rio Azul de La Union. The site where the landfill Rio Azul is located is composed by a sequence of volcanic materials, which could have been affected by local faulting. This fact would mean a serious threat of contamination of groundwater in the region, geological faults are therefore a highly permeable, able to get in touch the fill pollutants with some aquifer. The mass of metal deposited on the site, from 1978 to date, has been estimated between 70000-100000 tm, which it becomes environmental concern in a first order. The results of X-ray fluorescence show the presence of elements such as vanadium, chromium, magnesium, copper, zinc, rubidium, strontium, potassium, calcium, iron, titanium and yttrium, which show a trend towards more high Concentrates in the fine fraction (d [es

  16. APPLICATION OF DIATOMS TO ASSESS THE QUALITY OF THE WATERS OF THE BARYCZKA STREAM, LEFT-SIDE TRIBUTARY OF THE RIVER SAN

    Directory of Open Access Journals (Sweden)

    Teresa Noga

    2013-07-01

    Full Text Available The Baryczka stream is a small (about 20 km long, left bank tributary of the River San (Podkarpackie Voivodeship. Studies on diversity of diatom communities using OMNIDIA software were conducted in 2010 and 2011. Diatomaceous indices IPS, GDI and TDI and Van Dam et al. classification system were used for water quality assessment. Planothidium lanceolatum, Cocconeis placentula var. lineata, Achnanthidium minutissimum var. minutissimum, Nitzschia linearis, Rhoicosphenia abbreviata, Navicula lanceolata and Naicula gregaria were the most numerous. Values of the IPS index indicate good water quality (II–III class. Based on the GDI index, waters of the Baryczka stream were classified to III class water quality. The TDI index indicated poor and bad ecological state on the most sampling sites. On all sampling sites alaliphilous (pH>7 diatoms taxa predominated. The most common were eutraphentic and hypereutraphentic diatoms. With respect to trophy, it was shown that α- and β-mesosaprobous diatoms were the most common (III and II class water quality.

  17. Influence of anthropogenic alterations on geomorphic response to climate variations and change in San Francisco Bay-Delta and watershed

    Science.gov (United States)

    Florsheim, J.L.; Dettinger, M.D.

    2004-01-01

    Global warming and attendant sea-level rise may soon impact geomorphic processes in the Sacramento-San Joaquin River and San Francisco Bay Delta systems. During the past two centuries, dramatic anthropogenic changes in sediment supply and pervasive structural controls on rivers and floodplains have altered geomorphic responses to floods throughout a zone that extends upstream from tidally influenced areas to dams that regulate flow. Current geomorphic responses to floods differ from natural responses due to historical actions that concentrated the pre-disturbance multiple-channel and flood-basin system into single channels isolated by levees from increasingly developed floodplains and flood bypass channels, altered flow and sediment regimes, and caused subsidence of leveed Delta Islands. A review of historic and current geomorphic responses to floods illustrates the dominance of structural controls on geomorphic changes in the lowland part of the Sacramento-San Joaquin system. Current climate-change projections for CA suggest that the total volume of snowmelt runoff that may be shifted from spring and added to winter flows is roughly 5 maf/yr, similar to the volume currently available for flood storage in Sierra Nevadan reservoirs. Changes in timing of reservoir releases to accommodate these changes could add to either the magnitude or duration of winter flood peaks, each causing different geomorphic responses. Increased wintertime flows that accompany already large floods could increase overbank flood extent, erosion, and sedimentation, or alternatively increase the depth and strength of confined flows and increase the risk of levee failures. Runoff released from reservoirs as a relatively constant addition to winter baseflow would increase the duration of bankfull or possibly "levee-full" flows. This scenario could lead to bank and levee failure through increased saturation and seepage erosion. Projected sea level rise of 1-2 m would compound vulnerability of

  18. Electrokinetic remediation of mercury- contaminated soil, from the mine El Alacran-San Jorge river basin, Cordoba- Colombia

    Directory of Open Access Journals (Sweden)

    José Luis Marrugo Negrete

    2013-01-01

    Full Text Available El objetivo de este trabajo fue evaluar la técnica electrocinética para la remediación de suelos contaminados con mercurio de la mina El Alacrán, ubicada en la cuenca del río San Jorge en el departamento de Córdoba, Colombia. Soluciones de KI y NaCl fueron usadas como agentes complejantes para la remoción del mercurio en dos concentraciones 0.01 y 0.05 M, aplicando voltajes de 30 y 40 V respectivamente. Los mejores resultados fueron obtenidos cuando el KI se usó como agente complejante, alcanzando porcentajes de recuperación hasta de 98.7%. los tratamientos donde el NaCl se usó como agente complejante no alcanzaron recuperaciones significativas (< 1%, excepto cuando se usó una concentración de 0.05 M de NaCl con un voltaje de 40 V alcanzando una recuperación de 38%. En todos los experimentos, el mercurio se movió hacia el ánodo, debido a la formación de complejos de naturaleza aniónica y se observó que incrementando la concentración y el voltaje, una mayor eficiencia y velocidad de remoción de mercurio del suelo fue alcanzada. Los resultados muestran que el ioduro tiene propiedades que lo hacen una solución electrolítica prometedora para la remoción del mercurio en suelos contaminados.

  19. Hydrogeologic Assessment of the East Bear Creek Unit, San LuisNational Wildlife Refuge

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Nigel W.T.

    2007-07-15

    San Luis National Wildlife Refuge Complex to meetReclamation s obligations for Level 4 water supply under the CentralValley Project Improvement Act. Hydrogeological assessment of the EastBear Creek Unit of the San Luis National Wildlife Refuge was conductedusing a combination of field investigations and a survey of availableliterature from past US Geological Survey Reports and reports by localgeological consultants. Conservative safe yield estimates made using theavailable data show that the East Bear Creek Unit may have sufficientgroundwater resources in the shallow groundwater aquifer to meet aboutbetween 25 percent and 52 percent of its current Level II and between 17percent and 35 percent of its level IV water supply needs. The rate ofsurface and lateral recharge to the Unit and the design of the well fieldand the layout and capacity of pumped wells will decide both thepercentage of annual needs that the shallow aquifer can supply andwhether this yield is sustainable without affecting long-term aquiferquality. In order to further investigate the merits of pumping the nearsurface aquifer, which appears to have reasonable water quality for usewithin the East Bear Creek Unit -- monitoring of the potential sources ofaquifer recharge and the installation of a pilot shallow well would bewarranted. Simple monitoring stations could be installed both upstreamand downstream of both the San Joaquin River and Bear Creek and beinstrumented to measureriver stage, flow and electrical conductivity.Ideally this would be done in conjunction with a shallow pilot well,pumped to supply a portion of the Unit's needs for the wetland inundationperiod.

  20. Geochemical investigations and interim recommendations for priority abandoned mine sites, BLM lands, upper Animas River watershed, San Juan County, Colorado

    Science.gov (United States)

    Nash, J. Thomas

    1999-01-01

    Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the U. S. Bureau of Land Management (BLM) in the Upper Animas River watershed. Results of chemical analyses of dump materials, leachates of those materials, and surface waters draining mines or dumps provide indications of where acid is generated or consumed, and metal concentrations below mines or dumps. Information on sites previously identified as needing reclamation is reviewed and available geochemical information is used to rank 26 sites into four classes of priority for reclamation. Although there are more than a thousand mining sites (productive mines and prospects) on BLM lands in the Upper Animas River watershed study area, the majority are very small (less than about 70 cubic yards of dump material), are more than 2 miles from a major stream, or so inaccessible as to prohibit reclamation. In the summers of 1997 and 1998 approximately 200 sites were observed and more than 100 of these that appeared to have the potential to geochemically impact the watershed were examined more carefully and sampled. Building upon the prior work of the BLM and associated agencies, this work attempted to identify the most significant sources of mine-related contamination and to rank those sites as to priority for reclamation. These most significant mining areas have been examined within a geologic framework and were evaluated by multiple criteria, including tendency to generate acid and release toxic metals, observed damage to vegetation, potential to release metals based on leach tests, and likelihood of transport into streams of the watershed. No single measurable parameter, such as metal concentration, can be used to rank the sites. Rather, subjective estimates are required to evaluate combinations or interactions among several parameters. The most subjective estimate, while ranking

  1. A Tidally Averaged Sediment-Transport Model for San Francisco Bay, California

    Science.gov (United States)

    Lionberger, Megan A.; Schoellhamer, David H.

    2009-01-01

    A tidally averaged sediment-transport model of San Francisco Bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity, a conservative tracer (Uncles and Peterson, 1995; Knowles, 1996). The Bay is represented in the model by 50 segments composed of two layers: one representing the channel (>5-meter depth) and the other the shallows (0- to 5-meter depth). Calculations are made using a daily time step and simulations can be made on the decadal time scale. The sediment-transport model includes an erosion-deposition algorithm, a bed-sediment algorithm, and sediment boundary conditions. Erosion and deposition of bed sediments are calculated explicitly, and suspended sediment is transported by implicitly solving the advection-dispersion equation. The bed-sediment model simulates the increase in bed strength with depth, owing to consolidation of fine sediments that make up San Francisco Bay mud. The model is calibrated to either net sedimentation calculated from bathymetric-change data or measured suspended-sediment concentration. Specified boundary conditions are the tributary fluxes of suspended sediment and suspended-sediment concentration in the Pacific Ocean. Results of model calibration and validation show that the model simulates the trends in suspended-sediment concentration associated with tidal fluctuations, residual velocity, and wind stress well, although the spring neap tidal suspended-sediment concentration variability was consistently underestimated. Model validation also showed poor simulation of seasonal sediment pulses from the Sacramento-San Joaquin River Delta at Point San Pablo because the pulses enter the Bay over only a few days and the fate of the pulses is determined by intra-tidal deposition and resuspension that are not included in this tidally averaged model. The model was calibrated to net-basin sedimentation to calculate budgets of sediment and sediment-associated contaminants. While

  2. Riigi eelarvepoliitika peab olema neutraalne / Joaquin Almunia ; interv. Piret Reiljan

    Index Scriptorium Estoniae

    Almunia, Joaquin, 1948-

    2008-01-01

    Euroopa Komisjoni rahandusvoliniku Joaquin Almunia sõnul peaks Eesti vältima järeleandmisi eelarvepoliitikas, samuti tuleks prioriteediks seada investeeringud, mis toetavad majanduskasvu ning kasutada ära maksimaalselt Euroopa Liidu struktuurifonde

  3. Sedimentological and Micropaleontological Characteristics of the 2015 Hurricane Joaquin Deposit and their Implications for Long-Term Records of Storms and Tsunamis Impacting the Caribbean

    Science.gov (United States)

    Kosciuch, T. J.; Pilarczyk, J.; Reinhardt, E. G.; Mauviel, A.; Aucoin, C. D.

    2017-12-01

    The uncertainty of extreme wave events in the Caribbean was highlighted in October 2015 when Hurricane Joaquin tracked through, or near, several islands (e.g., Bahamas, Haiti, Turks and Caicos) as a Category 4 storm. The short observational record of landfalling hurricanes is insufficient in preparing many of these islands for such a rare, intense storm. Examining the sediments deposited by recent landfalling hurricanes assists the understanding of the long-term spatial and temporal variations in storm frequency and intensity. However, the interpretation of prehistoric hurricane deposits in the Caribbean is complicated by the possibility of tsunami deposits (e.g., Puerto Rico Trench, 1755 Lisbon Tsunami), which are similar in composition and difficult to differentiate from storm sediments. To circumvent this problem, we describe the microfossil and sedimentary characteristics of a modern storm analogue, the Hurricane Joaquin deposit, from San Salvador Island in the Bahamas and use it as a basis for interpreting a series of 10 anomalous sand deposits found in a coastal pond. San Salvador is a small (160 km2) island in the Bahamas with a history of landfalling hurricanes and tsunamis. On 4 October 2015, Hurricane Joaquin came within 7 km of San Salvador, inundating most of its coastline and depositing two distinct layers: a sand layer and a boulder layer. The sand layer was 12 to 104 cm thick, extended 135 m inland, and consisted of fine to medium sand. The sand layer contained high abundances of foraminifera, including Homotrema rubra, a foraminifer that lives on the reef and is detached by large waves. The presence of well-preserved fragments of Homotrema within the Joaquin deposit suggests transport from the reef and rapid burial. The boulder layer included large clasts (30 to 200 cm in length) that were imbricated perpendicular to the shoreline and extended 135 m inland. The boulder layer was more laterally extensive (1020 m) than the sand layer (110 m). The

  4. Managing Environmental Flows for Impounded Rivers in Semi-Arid Regions- A Habitat Suitability Index (HSI) Approach for the Assessment of River Habitat for Salmonid Populations

    Science.gov (United States)

    Pai, H.; Sivakumaran, K.; Villamizar, S. R.; Flanagan, J.; Guo, Q.; Harmon, T. C.

    2013-12-01

    Balancing ecosystem health in water-scarce, agriculturally dominated river basins remains a challenge. In dry water years, maintaining conditions for restored and sustained indigenous fish populations (a frequently used indicator for ecosystem health) is particularly challenging. Competing human demands include urban and agricultural water supplies, hydropower, and flood control. In many semi-arid regions, increasing drought intensity and frequency under future climate scenarios will combine with population increases to water scarcity. The goal of this work is to better understand how reservoir releases affect fish habitat and overall river aquatic ecosystem quality. Models integrating a diverse array of physical and biological processes and system state are used to forecast the river ecosystem response to changing drivers. We propose a distributed parameter-based Habitat Suitability Index (HSI) approach for assessing fish habitat quality. Our river ecosystem HSI maps are based on a combination of the following: (1) In situ data describing stream flow and water quality conditions; (2) Spatial observations, including surveyed cross-sections, aerial imagery and digital elevation maps (DEM) of the river and its riparian corridor; and (3) Simulated spatially distributed water depths, flow velocities, and temperatures estimated from 1D and 2D river flow and temperature models (HEC-RAS and CE-QUAL-W2, respectively). With respect to (2), image processing schemes are used to classify and map key habitat features, namely riparian edge and shallow underwater vegetation. HSI maps can be modified temporally to address specific life cycle requirements of indicator fish species. Results are presented for several reaches associated with the San Joaquin River Restoration Project, focusing on several components of the Chinook salmon life cycle. HSI maps and interpretations are presented in the context of a range of prescribed reservoir release hydrographs linked to California water

  5. Angelberga: il monastero di San Sisto di Piacenza e il corso del fiume Po Angelberga: the monastery of St. Sisto of Piacenza and the course of Po river

    Directory of Open Access Journals (Sweden)

    Roberta Cimino

    2012-10-01

    Full Text Available Il contributo analizza il dotario of Angelberga (ca. 831-891, moglie dell’imperatore Ludovico II. Angelberga rivestì un importante ruolo politico sia durante il suo matrimonio, sia dopo la morte del marito, e riuscì inoltre a costruire un impressionante patrimonio. Angelberga acquisì infatti un grande numero di beni fondiari, in parte tramite donazioni del consorte e in parte grazie ad acquisizioni personali. Nell’877 l’imperatrice assegnò il suo patrimonio al monastero di San Sisto, da lei fondato a Piacenza. Il contributo esamina in dettaglio l’ubicazione dei beni di Angelberga, dimostrando che gran parte di tali beni era situata in prossimità del corso del fiume Po: tale collocazione consentiva il controllo delle principali vie di comunicazione del regno d’Italia. Inoltre le proprietà di Angelberga si trovavano per lo più in aree controllate dai Supponidi, la potente famiglia di origine dell’imperatrice. Il saggio conclude che la costruzione del patrimonio di Angelberga, e del monastero che ne derivò, dimostra una convergenza di interessi economici e politici tra il potere regio e le aristocrazie locali rappresentate dalla potente famiglia d’origine dell’imperatrice.

    This study analyzes the dower of Angelberga (ca. 831-891, wife of emperor Louis II. Angelberga played a significant political role during her marriage and after her husband’s death; moreover she accumulated an impressive patrimony. Angelberga gathered a great number of landed properties, partly through donations from her husband and partly thanks to personal acquisitions. In 877 the empress left her wealth to the monastery of St. Sisto, which she had founded in Piacenza. This article offers a detailed analysis of the location of Angelberga’s properties, showing that most of these properties were situated in the proximity of the Po river: this location allowed for the control of the main communication routes of the Italic Kingdom. Moreover

  6. A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Ted Sommer

    2013-06-01

    Full Text Available We used a combination of published literature and field survey data to synthesize the available information about habitat use by delta smelt Hypomesus transpacificus, a declining native species in the San Francisco Estuary. Delta smelt habitat ranges from San Pablo and Suisun bays to their freshwater tributaries, including the Sacramento and San Joaquin rivers. In recent years, substantial numbers of delta smelt have colonized habitat in Liberty Island, a north Delta area that flooded in 1997. The species has a more upstream distribution during spawning as opposed to juvenile rearing periods. Post-larvae and juveniles tend to have a more downstream distribution during wetter years. Delta smelt are most common in low-salinity habitat (<6 psu with high turbidities (>12 NTU and moderate temperatures (7 °C to 25 °C. They do not appear to have strong substrate preferences, but sandy shoals are important for spawning in other osmerids. The evidence to date suggests that they generally require at least some tidal flow in their habitats. Delta smelt also occur in a wide range of channel sizes, although they seem to be rarer in small channels (<15 m wide. Nonetheless, there is some evidence that open water adjacent to habitats with long water-residence times (e.g. tidal marsh, shoal, low-order channels may be favorable. Other desirable features of delta smelt habitat include high calanoid copepod densities and low levels of submerged aquatic vegetation (SAV and the toxic algae Microcystis. Although enough is known to plan for large-scale pilot habitat projects, these efforts are vulnerable to several factors, most notably climate change, which will change salinity regimes and increase the occurrence of lethal temperatures. We recommend restoration of multiple geographical regions and habitats coupled with extensive monitoring and adaptive management. An overall emphasis on ecosystem processes rather than specific habitat features is also likely to be

  7. The Maiestas of the 1162 Bible of San Isidoro de León in the Museo Arqueológico Nacional (Madrid

    Directory of Open Access Journals (Sweden)

    Ana Hernández

    2017-06-01

    Full Text Available Joaquin Yarza has attributed a loose folio containing a full-page representation of the Maiestas in the MAN to the 1162 Bible of San Isidoro de León. A comparative analysis of both works and documentary evidence confirm this identification, thereby deepening our understanding of the works.

  8. San Francisco District Laboratory (SAN)

    Data.gov (United States)

    Federal Laboratory Consortium — Program CapabilitiesFood Analysis SAN-DO Laboratory has an expert in elemental analysis who frequently performs field inspections of materials. A recently acquired...

  9. Simulation of climate change in San Francisco Bay Basins, California: Case studies in the Russian River Valley and Santa Cruz Mountains

    Science.gov (United States)

    Flint, Lorraine E.; Flint, Alan L.

    2012-01-01

    As a result of ongoing changes in climate, hydrologic and ecologic effects are being seen across the western United States. A regional study of how climate change affects water resources and habitats in the San Francisco Bay area relied on historical climate data and future projections of climate, which were downscaled to fine spatial scales for application to a regional water-balance model. Changes in climate, potential evapotranspiration, recharge, runoff, and climatic water deficit were modeled for the Bay Area. In addition, detailed studies in the Russian River Valley and Santa Cruz Mountains, which are on the northern and southern extremes of the Bay Area, respectively, were carried out in collaboration with local water agencies. Resource managers depend on science-based projections to inform planning exercises that result in competent adaptation to ongoing and future changes in water supply and environmental conditions. Results indicated large spatial variability in climate change and the hydrologic response across the region; although there is warming under all projections, potential change in precipitation by the end of the 21st century differed according to model. Hydrologic models predicted reduced early and late wet season runoff for the end of the century for both wetter and drier future climate projections, which could result in an extended dry season. In fact, summers are projected to be longer and drier in the future than in the past regardless of precipitation trends. While water supply could be subject to increased variability (that is, reduced reliability) due to greater variability in precipitation, water demand is likely to steadily increase because of increased evapotranspiration rates and climatic water deficit during the extended summers. Extended dry season conditions and the potential for drought, combined with unprecedented increases in precipitation, could serve as additional stressors on water quality and habitat. By focusing on the

  10. San Marino.

    Science.gov (United States)

    1985-02-01

    San Marino, an independent republic located in north central Italy, in 1983 had a population of 22,206 growing at an annual rate of .9%. The literacy rate is 97% and the infant mortality rate is 9.6/1000. The terrain is mountainous and the climate is moderate. According to local tradition, San Marino was founded by a Christian stonecutter in the 4th century A.D. as a refuge against religious persecution. Its recorded history began in the 9th century, and it has survived assaults on its independence by the papacy, the Malatesta lords of Rimini, Cesare Borgia, Napoleon, and Mussolini. An 1862 treaty with the newly formed Kingdom of Italy has been periodically renewed and amended. The present government is an alliance between the socialists and communists. San Marino has had its own statutes and governmental institutions since the 11th century. Legislative authority at present is vested in a 60-member unicameral parliament. Executive authority is exercised by the 11-member Congress of State, the members of which head the various administrative departments of the goverment. The posts are divided among the parties which form the coalition government. Judicial authority is partly exercised by Italian magistrates in civil and criminal cases. San Marino's policies are tied to Italy's and political organizations and labor unions active in Italy are also active in San Marino. Since World War II, there has been intense rivalry between 2 political coalitions, the Popular Alliance composed of the Christian Democratic Party and the Independent Social Democratic Party, and the Liberty Committee, coalition of the Communist Party and the Socialist Party. San Marino's gross domestic product was $137 million and its per capita income was $6290 in 1980. The principal economic activities are farming and livestock raising, along with some light manufacturing. Foreign transactions are dominated by tourism. The government derives most of its revenue from the sale of postage stamps to

  11. Don Joaquin García Monge

    Directory of Open Access Journals (Sweden)

    Agustín Rodríguez Garavito

    1958-11-01

    Full Text Available Los conocimos personalmente y tratamos de cerca en su amada ciudad de San José de Costa Rica. Casi diariamente íbamos por su casa. Una mansión grande, de vastos y sonoros corredores, arcones antiguos, libros apilados por doquier. Don Joaquín mantenía el timón de El Repertorio Americano, una de las más nobles publicaciones intelectuales del Continente. Dialogábamos con él sobre temas de mucha entidad, mientras la noche caía lentamente sobre este dulce país de porcelana tan grato a las veladas antiguas, aquellas donde se puede oír el latido del corazón como en el poema chino.

  12. EDXRF Analysis of pigments of the Joaquin Sorolla Artistic Paintings

    International Nuclear Information System (INIS)

    Ferrero, Jose L.; Roldan Clodoaldo, David; Mario Alvarez, Juanes

    1999-01-01

    The study of the pictorial work of Joaquin Sorolla has not been carried out from the point of view of the scientific analysis. Analytical techniques give us objective information about materials and process used in artistic works of art. In this sense, the Archaeometry Unit of the Institute of Material Science of the Valencia University (ICMUV), has carried out the first analysis of pigments of the paintings of Sorolla by Energy Dispersive X-Ray Fluorescence(EDXRF)

  13. Environmental sensor networks and continuous data quality assurance to manage salinity within a highly regulated river basin

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T.; Ortega, R.; Holm, L.

    2010-01-05

    This paper describes a new approach to environmental decision support for salinity management in the San Joaquin Basin of California that focuses on web-based data sharing using YSI Econet technology and continuous data quality management using a novel software tool, Aquarius.

  14. Structure and distribution of Hydrachnidia (Parasitengona-Acari in the sub-basin of the Grande River (Superior Basin of Quinto River. San Luis-Argentina Estrutura e distribuição dos Hidracáridos (Parasitengona-Acari na Subcuenca do Rio Grande (Conta Superior do Rio Quinto. San Luis-Argentina

    Directory of Open Access Journals (Sweden)

    Carlos Raul Quiroga

    2010-09-01

    Full Text Available AIM: The purpose of this work was to determine genera diversity, structural attributes and distribution of the Hydrachnidia assemblages and their possible influences with certain abiotic parameters along the sub-basin of the Grande River, a 6th order stream in the province of San Luis; METHODS: four sampling sites (C1, E1, E2 and E3 were established in two different hydrological periods: high waters (HW and low waters (LW. Twenty-four samples were obtained using Surber sampler, and the hydraulic, physical and chemical characterization of the sampling sites was carried out. Density (ind.m-2, genus richness, Shannon-Wiener diversity index and Kownacki's dominance index were calculated; RESULTS: sixteen Hydrachnidia genera were observed. No significant differences were found between the abiotic parameters of each site. A positive correlation of Sperchon, Torrentícola and Neoatractides was observed in relation to flow and current velocity whereas Hygrobates showed a negative correlation. No significant differences were observed in Hydrachnidia abundances among the sites in HW and LW and between the pairs of each site in HW and LW. The genera with the highest densities were Hygrobates, Limnesia and Atractides, of which the first two were widely distributed. The rest only appeared sporadically. According to Kownacki's index Hygrobates and Limnesia were "dominant", Atractides were "subdominant" and the rest were "non dominant"; CONCLUSIONS: The found genera were distanced systematically and philogenetically. However, the specimens belonging to these genera exhibited very similar morphological characteristics, which were adaptations to rheophilous habitats. The representativity of Hygrobates and Limnesia might be due to the great abundance of their hosts and preys in the sub-basin. The decrease in the densities and the changes in the Hydrachnidia composition in E3 (post-dam site might be explained by the biotic interactions previously mentioned

  15. Evaluación ambiental del río San Juan de Santiago de Cuba por exposición bioacumulativa a metales pesados Environmental evaluation of San Juan river in Santiago de Cuba due to bioaccumulative exposure to heavy metals

    Directory of Open Access Journals (Sweden)

    George Argota Pérez

    2012-08-01

    Full Text Available Se evaluó la salud ambiental del río San Juan de Santiago de Cuba, expuesto a metales pesados, mediante la utilización de la especie biorreguladora Gambusia punctata. Se analizaron 271 individuos adultos clasificados por sexo, para lo cual se escogieron los intervalos de clases de edades 2,1-3,0 y 3,1-4,0 cm, según la longitud total, respectivamente. La mezcla ácida aplicada estuvo compuesta por ácido perclórico - ácido sulfúrico; (7:1 ácido nítrico para determinar los niveles bioacumulados en hígado, branquias y cerebro como órganos diana. Los metales analizados: cobre, zinc, plomo y cadmio, se cuantificaron mediante espectrometría por plasma inductivamente acoplado con vista axial. Se hallaron diferencias significativas (pThe environmental health of San Juan river in Santiago de Cuba, exposed to heavy metals was evaluated by means of the bioregulatory species Gambusia punctata. Two hundred and seventy five adults were analyzed and classified by sex, for whom the intervals of age classes 2.1-3.0 and 3.1-4.0 cm were chosen, according to the total longitude, respectively. The applied acid mixture was composed by perchloric acid - sulphuric acid; (7:1 nitric acid to determine the bioaccumulated levels in liver, branchiae and brain as target organs. The analyzed metals: copper, zinc, lead and cadmium, were quantified by means of spectrometry by plasma inductively coupled with axial view. There were significant differences (p <0.05 in the bioaccumulated values between intervals and sexes. It was concluded that the levels of bioaccumulated heavy metals overcame the permissible values, so that they represent an environmental risk in the quality of those waters.

  16. 75 FR 4745 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Science.gov (United States)

    2010-01-29

    ... per hour or less and that are fired exclusively on natural gas or liquefied petroleum gas (LPG) (see... described above but also establishes the following specifications for both natural gas and LPG combusted by... exemption would establish separate specifications for natural gas and for LPG. The hydrocarbon content limit...

  17. 76 FR 39777 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollutions...

    Science.gov (United States)

    2011-07-07

    ... from crude oil production operations and refineries. Under authority of the Clean Air Act as amended in... in SJVUAPCD Rule 4455, ``Components at Petroleum Refineries, Gas Liquids Processing Facilities and... are hesitant to divert resources to conduct work that is not demonstrated to have significant...

  18. Equations for predicting diameter, height, crown width, and leaf area of San Joaquin Valley street trees

    Science.gov (United States)

    P.J. Peper; E.G. McPherson; S.M. Mori

    2001-01-01

    Although the modeling of energy-use reduction, air pollution uptake, rainfall interception, and microclimate modification associated with urban trees depends on data relating diameter at breast height (dbh) , crown height, crown diameter, and leaf area to tree age or dbh, scant information is available for common municipal tree species . I n this study , tree height ,...

  19. Optimizing reserve expansion for disjunct populations of San Joaquin kit fox

    Science.gov (United States)

    Robert G. Haight; Brian Cypher; Patrick A. Kelly; Scott Phillips; Katherine Ralls; Hugh P. Possingham

    2004-01-01

    Expanding habitat protection is a common strategy for species conservation. We present a model to optimize the expansion of reserves for disjunct populations of an endangered species. The objective is to maximize the expected number of surviving populations subject to budget and habitat constraints. The model accounts for benefits of reserve expansion in terms of...

  20. Support Services for Exceptional Students: Alameda, Contra Costa, Napa, San Joaquin, and Solano Counties.

    Science.gov (United States)

    Hampel, Angelica; Maloney, Patricia

    Intended for use by vocational administrators responsible for mainstreaming handicapped students into vocational education classes, the resource guide lists and describes governmental and private agencies that provide vocational programs and support services for the handicapped on a local and statewide basis in the California counties of Alameda,…

  1. 75 FR 26102 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Science.gov (United States)

    2010-05-11

    ... agricultural sources from the offset requirement does not conflict with the Clean Air Act. Dairy Cares points... District, New Source Review AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA... provide for review of new and modified stationary sources (``new source review'' or NSR) within the...

  2. 78 FR 46504 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Science.gov (United States)

    2013-08-01

    ....' Subdivision (b) does not authorize district New Source Review rules that conflict with the sections of SB 700... Review rules that conflict with SB 700's provisions concerning the New Source Review process. Subdivision... not grant authority, and does not authorize New Source Review rules that conflict with other sections...

  3. 77 FR 65305 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley Unified Air...

    Science.gov (United States)

    2012-10-26

    ... the exhaustion of all administrative and judicial appeals processes (including any associated remand... subject to the CEC certification process do not satisfy the CAA's requirements for judicial review. The... process under CPRC 25531 differs in a number of respects from the administrative and judicial review...

  4. 76 FR 76112 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Science.gov (United States)

    2011-12-06

    ... particular nights are not necessarily insignificant from the standpoint of PM 10 and PM 2.5 formation... winter nights to provide frost protection for certain type of crops (like citrus) when temperatures are... reasonably be estimated at approximately 15 pounds per day of NO X .\\1\\ \\1\\ Most engines are fired on propane...

  5. 76 FR 40660 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2011-07-11

    ... Report 05/20/10 04/05/11 and Recommendations on Agricultural Burning. On May 6, 2011, EPA determined that... disease, decreased lung function, visibility impairment, and damage to vegetation and ecosystems. Section... open burning of agricultural waste and other materials. Rule 4103 was revised largely to implement...

  6. 76 FR 57845 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley; Attainment Plan for...

    Science.gov (United States)

    2011-09-16

    ... Stationary Gas Turbines....... 4703 3rd Q--2007 September 2007 74 FR 53888 (October 21, 2009). S-IND-24 Soil Decontamination......... 4651 3rd Q--2007 September 2007 74 FR 52894 (October 15, 2009). S-IND-6 Polystyrene Foam...

  7. High Quantile of Environmental Screening Methods, San Joaquin Valley CA, 2013, Occidental College of Los Angeles

    Data.gov (United States)

    U.S. Environmental Protection Agency — This layer combines the high quantiles of the CES, CEVA, and EJSM layers so that viewers can see the overlap of â??hot spotsâ?? for each method. This layer was...

  8. 75 FR 74517 - Approval and Promulgation of Implementation Plans; State of California; 2008 San Joaquin Valley...

    Science.gov (United States)

    2010-11-30

    ... formed in the atmosphere as a result of various chemical reactions from precursor emissions of nitrogen... air quality modeling, the reasonable further progress (RFP) demonstration, the contingency measures... Modeling in the SJV 2008 PM 2.5 Plan 3. PM 2.5 Attainment Plan Precursors 4. Extension of the Attainment...

  9. Subsidence, Sea Level Rise, and Seismicity in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Jeffrey Mount

    2005-03-01

    Full Text Available Anthropogenic accommodation space, or that space in the Delta that lies below sea level and is filled neither with sediment nor water, serves as a useful measure of the regional consequences of Delta subsidence and sea level rise. Microbial oxidation and compaction of organic-rich soils due to farming activity is the primary cause of Delta subsidence. During the period 1900-2000, subsidence created approximately 2.5 billion cubic meters of anthropogenic accommodation space in the Delta. From 2000-2050, subsidence rates will slow due to depletion of organic material and better land use practices. However, by 2050 the Delta will contain more than 3 billion cubic meters of anthropogenic accommodation space due to continued subsidence and sea level rise. An Accommodation Space Index, which relates subaqueous accommodation space to anthropogenic accommodation space, provides an indicator of past and projected Delta conditions. While subsidence and sea level rise create increasing anthropogenic accommodation space in the Delta, they also lead to a regional increase in the forces that can cause levee failure. Although these forces take many forms, a Levee Force Index can be calculated that is a proxy for the cumulative forces acting on levees. The Levee Force Index increases significantly over the next 50 years demonstrating regional increases in the potential for island flooding. Based on continuing increases in the Levee Force Index and the Accommodation Space Index, and limited support for Delta levee upgrades, there will be a tendency for increases in and impacts of island flooding, with escalating costs for repairs. Additionally, there is a two-in-three chance that 100-year recurrence interval floods or earthquakes will cause catastrophic flooding and significant change in the Delta by 2050. Currently, the California Bay-Delta Authority has no overarching policy that addresses the consequences of, and potential responses to, gradual or abrupt landscape change in the Delta.

  10. 75 FR 3996 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2010-01-26

    ... and that it was, therefore, hesitant to ``divert resources to unnecessary bureaucratic work associated... small businesses, small not-for-profit enterprises, and small governmental jurisdictions. This rule will...

  11. Limited site review for the San Joaquin Nuclear Project. Project No. 499

    International Nuclear Information System (INIS)

    1977-06-01

    This report is the Nuclear Regulatory Commission's (Commission) safety evaluation of a proposed site near Bakersfield, California, on which the Los Angeles Department of Water and Power (applicant) in association with a number of other organizations proposes to build a nuclear facility at a future date. A construction permit application has not been filed but the applicant has informed us of its intention to submit an Environmental Report during February 1980 and a Preliminary Safety Analysis Report during May 1980

  12. 77 FR 64427 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-10-22

    ... with Steve Fields (California Department of Oil, Gas, and Geothermal Resources), August 1, 2012. \\2... VOC content) vary widely with the geological properties of the oil wells and the fact that a few... conversation with Steve Fields (California Department of Oil, Gas and Geothermal Resources), August 1, 2012. \\8...

  13. 77 FR 12651 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley; Attainment Plan for...

    Science.gov (United States)

    2012-03-01

    ... jointly by the Center on Race, Poverty and the Environment; Earthjustice; and the Natural Resources... F.2d 764, 769-71 (2d Cir. 1992); Cate v. Transcontinental Gas Pipe Line Corp., 904 F. Supp. 526, 530... vehicular sources and non-vehicular (stationary source) controls. As to the former, the SIP revision...

  14. 76 FR 26609 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-05-09

    ... Shipping Ass'n v. Goldstene, 517 F.3d 1108 (9th Cir. 2008), by noting that the regulations in those cases..., EMA v. EPA and Pacific Merchant Shipping Ass'n v. Goldstene, 2009 U.S. Dist Lexis 55516, 70 ERC 1337.... Rd. & Transp. Builders Ass'n v. EPA, 588 F.3d 1109 (DC Cir. 2009), petition for cert. denied, No. 09...

  15. 75 FR 2079 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Science.gov (United States)

    2010-01-14

    ... proposal: (1) Rule 4570 fails to require controls for all major poultry operations; (2) SJVAPCD failed to... additional controls would advance the attainment date of the ozone standard belongs in the context of SJVAPCD... industries can afford controls costing 10% of profits or more without impacting economic viability. EJ...

  16. 77 FR 71129 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Science.gov (United States)

    2012-11-29

    ...EPA is finalizing approval of revisions to the SJVUAPCD and SCAQMD portion of the California State Implementation Plan (SIP). This action was proposed in the Federal Register on June 21, 2012 and concerns volatile organic compound (VOC) emissions from chipping and grinding activities, and composting operations. We are approving local rules that regulate these emission sources under the Clean Air Act (CAA or the Act).

  17. Traffic-Related Air Pollution and Selected Birth 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 W.; Shaw, Gary M.

    2014-01-01

    BACKGROUND Birth defects are a leading cause of infant morbidity and mortality. Studies suggest associations between environmental contaminants and some structural anomalies, although evidence is limited and several anomalies have not been investigated previously. 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 26 congenital birth defect phenotypes with respect to quartiles of seven ambient air pollutant and traffic exposures in California during the first 2 months of pregnancy, 1997 to 2006 (874 cases and 849 controls). We calculated odds ratios (adjusted for maternal race/ethnicity, education, and vitamin use; aOR) for 11 phenotypes that had at least 40 cases. RESULTS Few odds ratios had confidence intervals that did not include 1.0. Odds of esophageal atresia were increased for the highest versus lowest of traffic density (aOR = 2.8, 95% confidence interval [CI], 1.1–7.4) and PM10 exposure (aOR 4.9; 95% CI, 1.4–17.2). PM10 was associated with a decreased risk of hydrocephaly (aOR= 0.3; 95% CI, 0.1–0.9) and CO with decreased risk of anotia/microtia (aOR = 0.4; 95% CI, 0.2–0.8) and transverse limb deficiency (aOR = 0.4; 95% CI, 0.2–0.9), again reflecting highest versus lowest quartile comparisons. CONCLUSION Most analyses showed no substantive association between air pollution and the selected birth defects with few exceptions of mixed results. PMID:24108522

  18. 76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-11-03

    ... Area Air Quality Management District (BAAQMD).\\1\\ This was the low end of a range of estimates that... controls within the range of estimates developed by BAAQMD and the South Coast Air Quality Management....453 tons per year (tpy) per restaurant to potential UFC controls but never explains the basis for this...

  19. Environmental Justice Screening Method (EJSM) Score, San Joaquin Valley CA, 2013, Occidental College and UC Berkeley

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Cumulative Impacts (CI) screening method is jointly being developed by Manuel Pastor, Jim Sadd (Occidental College), and Rachel Morello-Frosch (UC Berkeley) ....

  20. 76 FR 33181 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-06-08

    ... aging and wine aging operations. EPA's technical support document (TSD) has more information about this...) emissions from brandy and wine aging operations. We are approving a local rule that regulates [[Page 33182... 4695 Brandy Aging and Wine Aging 09/17/09 05/17/10 Operations. On June 8, 2010, EPA determined that the...

  1. 76 FR 70886 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-11-16

    ... requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272...-volume reports), and some may not be available in either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business...

  2. 78 FR 6740 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Science.gov (United States)

    2013-01-31

    ... requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272..., multi- volume reports), and some may not be available in either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business...

  3. 77 FR 58312 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-09-20

    ... Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those...-volume reports), and some may not be available in either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business...

  4. 76 FR 53640 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2011-08-29

    ... National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those... available in either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business hours with the contact listed in the FOR...

  5. 77 FR 71109 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-11-29

    ... Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those... either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business hours with the contact listed in the FOR FURTHER...

  6. 77 FR 25384 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-04-30

    ... National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those..., unless the comment includes Confidential Business Information (CBI) or other information whose disclosure... during normal business hours with the contact listed in the FOR FURTHER INFORMATION CONTACT section. FOR...

  7. 77 FR 5709 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-02-06

    ... Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those... either location (e.g., confidential business information (CBI)). To inspect the hard copy materials, please schedule an appointment during normal business hours with the contact listed in the FOR FURTHER...

  8. 75 FR 1716 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2010-01-13

    ... NO X 12. Definition of ``Major Source'' 13. Sunset Provision for Section 185 Fees III. EPA Action IV... from Ted Steichen, dated September 18, 2009. 3. Association of Irritated Residents, letter from Brent... or emissions during the baseline period, or the amount of VOC or NO X emissions allowed under the...

  9. 77 FR 50021 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-08-20

    ... the required notice and comment procedures rendered the guidance invalid. NRDC v. EPA, 643 F.3d 311..., such as owners of mobile sources that also contribute to ozone formation. EPA also believes that... percent of ozone formation in SJVUAPCD.\\3\\ Our proposed action contains our analysis of how the District's...

  10. 1979-80 Financial Statistics for Current Cost of Education... Showing San Joaquin Delta College Position...

    Science.gov (United States)

    DeRicco, Lawrence A.

    The costs of education per unit of Average Daily Attendance (ADA) are detailed in this two-part report for 70 California community college districts for the academic year 1979-80. Both Part I, which presents data excluding non-resident ADA, and Part II, which presents figures including non-resident ADA, begin with tables which rank order the…

  11. 77 FR 2228 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-01-17

    ... ``feasible,'' more than one measure must be implemented. As a matter of theory, petitioners are, of course... actually reach it. CRPE further argues that dairies already have an incentive to not allow expensive feed... three feet away from the feedlane fence during site visits. Although there is financial incentive for...

  12. Mobility of major and trace elements in a coupled groundwater-surface water system: Merced River, CA

    Science.gov (United States)

    Wildman, R. A.; Domagalski, J. L.; Hering, J. G.

    2004-12-01

    Trace element transport in coupled surface water/groundwater systems is controlled not only by advective flow, but also by redox reactions that affect the partitioning of various elements between mobile and immobile phases. These processes have been examined in the context of a field project conducted by the U.S. Geological Survey (USGS) as part of the National Water-Quality Assessment (NAWQA) program. The Merced River flows out of Yosemite National Park and the Sierra Nevada foothills and into California's Central Valley, where it joins the San Joaquin River. Our field site is approximately twenty river kilometers from the confluence with the San Joaquin River. This deep alluvial plain has minimal topography. Agricultural development characterizes the land surrounding this reach of river; consequently, the hydrology is heavily influenced by irrigation. Riverbed groundwater samples were collected from ten wells aligned in two transects across the river located approximately 100 m apart. The wells were sampled from depths of 0.5 m, 1 m, and 3 m below the sediment-water interface. Groundwater flowpath samples were taken from wells positioned on a path perpendicular to the river and located 100 m, 500 m, and 1000 m from the river. The saturated groundwater system exists from 7 to 40 m below the surface and is confined below by a clay layer. Each well location samples from 3-5 depths in this surface aquifer. Samples were collected in December 2003, March-April, June-July, and October 2004. This served to provide an evenly-spaced sampling frequency over the course of a year, and also to allow observation of trends coinciding with the onset of winter, the spring runoff, and early and late summer irrigation. An initial survey of the elements in the riverbed samples was conducted using Inductively-Coupled Plasma Mass Spectrometry (ICP-MS). Elements for further study were selected based on variability in this survey, either with respect to depth or location, as well as to

  13. Long-term impacts due to sediment supply changes towards the San Francisco Bay-Delta system

    Science.gov (United States)

    Achete, F.; Van der Wegen, M. V.; Jaffe, B. E.

    2012-12-01

    The Sacramento-San Joaquin Delta and Watershed is the main source of fresh water and sediment to San Francisco Bay. Mid 19th century hydraulic mining in the catchment caused an excessive supply of sediment. After mining activities stopped, in the first part of the 20th century several hydraulic structures were built deviating fresh water and trapping sediment upstream. The main purpose of most of these structures is water storage for irrigation and/or water supply Wright and Schoellhamer (2004) show that from 1957 to 2001 the sediment load carried to San Francisco Bay has decreased by about one half. The lack of sediments may lead to a different erosion/deposition pattern in the Bay-Delta system causing problems like mud flat erosion, shift in navigation channel, land subsidence and changing habitat for endemic species. The objective of this work is to identify and quantify morphological shifts in the Bay-Delta system due to variation in fresh water and sediment supply. In this study, we couple the Delta and Bay in a unique model network (the Delta-Bay model). This coupling allows tracking of sediment from Sacramento via the Delta and Bay and through the Golden Gate, making it possible to identify erosion and deposition areas. The numerical model applied is an unstructured, process-based model (D-Flow Flexible Mesh developed by Deltares). It simulates the hydrodynamics and morphodynamics of the area on a detailed, 64000-node mesh (10-200m mesh length scale) on a timescale of minutes. The morphological impact is assessed for multiple scenarios with different input of sediment and fresh water. A statistical analysis is performed to account for uncertainty of model parameters and climate change impacts. The fresh water discharge already has a strong natural seasonal and inter-annual variation. The human impact by foreseen different water pumping strategies due to the peripheral canal will be considered. Jaffe et al. (2007) has shown that substantial morphological

  14. Suspended particulate matter flocculation in a natural tidal wetland located in the San Francisco Estuary

    Science.gov (United States)

    Saraceno, J.; Bergamaschi, B. A.; Wright, S. A.; Boss, E.; Downing, B. D.; Fleck, J.; Ganju, N. K.

    2011-12-01

    Suspended mineral and algal particles together comprise suspended particulate matter (SPM). The SPM size distribution influences the quantity and color of light penetration and the adsorption and transport of contaminants such as pesticides and metals. It is widely known that interaction with wetlands alters the size distribution and quality of particles through local primary production, differential settling and particle aggregation, however, our understanding of how tidal wetland processes affect SPM quantity and size spectra has been hampered by the difficulty of directly observing these parameters at tidal time scales. To evaluate how SPM concentration and size varied over tidal time scales and to better understand the relationship between organic matter and sediment characteristics, simultaneous measurements of dissolved organic matter, SPM concentration and organic content as well as in situ surrogates of particle concentration (turbidity, particulate attenuation, volume concentration) and particle size (laser diffraction) were carried out with measurements of current velocity (acoustic Doppler velocity meter) in the main channel of Brown's Island located in the western San Joaquin/Sacramento River Delta, CA. The study period coincided with high estuary sediment levels following a significant precipitation runoff event. In the Brown Island wetland, particle concentration and size dynamics were tied to variations in water level and velocity. Turbidity and attenuation covaried with the volume concentration of particles smaller than 33 um, which on average represented greater than 50% of particle population by volume. On average, these SPM concentration surrogates were three times higher in flood water than in ebb water; consistent with a loss of fine particles on the island. Following the highest flood tide, the decrease in fine particles was coincident with an increase in the concentration of particles larger than 130 um; a finding consistent with particle

  15. Trabajadores agrícolas en el valle de San Joaquín

    Directory of Open Access Journals (Sweden)

    Florencio Posadas Segura

    2012-06-01

    Full Text Available Agricultural workers are the backbone of the rural economy in California and the United States. More than 95 percent are Mexicans, especially in Michoa- can. An extensive fieldwork in the San Joaquin Valley, economic and demo- graphic indicators reveal that confirm the formation of various segments of employees: men and women, children, youth, adults and seniors, indigenous and non-indigenous residents and migrants, documented and undocumen- ted. This vast contingent reinforces the paradoxical trend toward increased production of agricultural wealth and the increasing poverty of authentic food producers.

  16. Diversidade genética de Enterolobium contortisiliquum (Vell. Morong. no Baixo Rio São Francisco, por meio de marcadores RAPD Genetic diversity of Enterolobium contortisiliquum (Vell. Morong. in the low San Francisco river by RAPD markers

    Directory of Open Access Journals (Sweden)

    Georgea da Cruz Santana

    2008-06-01

    Full Text Available Enterolobium contortisiliquum Vell. Morong (Leguminosae-Mimosoideae é uma espécie muito utilizada em programas de recuperação de matas ciliares no Baixo Rio São Francisco, devido ao seu rápido crescimento inicial. Assim, o objetivo deste trabalho foi avaliar, por meio de marcadores moleculares RAPD, a diversidade genética de oito indivíduos de uma população remanescente dessa espécie, visando contribuir para a definição de estratégias de coleta de sementes. Os indivíduos estão situados em uma área de 100 ha de mata ciliar do Baixo Rio São Francisco. Para a extração do DNA, pelo método CTAB 2%, foram utilizadas folhas tenras dos indivíduos. Testaram-se 20 oligonucleotídios de 10 bases de seqüência arbitrária, cujos produtos foram separados em gel de agarose 0,8%, submetidos à eletroforese horizontal, corados com brometo-de-etídio e visualizados em luz ultravioleta. A similaridade genética entre os indivíduos foi calculada pelo Coeficiente de Similaridade de Jaccard e a construção do dendrograma, realizada utilizando-se o método UPGMA. O valor médio de diversidade genética entre as matrizes foi de 49%, variando de 33 a 85%. Os indivíduos 6 e 7 apresentaram relativa proximidade genética (67%, não sendo indicado o plantio de suas mudas ou semeadura direta para recuperação de área ciliar em locais muito próximos. A partir dos resultados observados, podem-se desenvolver estratégias para a coleta de sementes e produção de mudas, auxiliando, assim, programas de restauração ambiental.Enterolobium contortisiliquum Vell. Morong (Leguminosae-Mimosoideae is very much used in riparian forest restoration programs in the Low San Francisco River because of its fast initial growth. The objective of this work was to evaluate by RAPD molecular markers the genetic diversity of eight individuals of a remaining population of this species, in order to contribute for the definition of strategies for seed production. The

  17. Factors Contributing to the Interrupted Decay of Hurricane Joaquin (2015) in a Moderate Vertical Wind Shear Environment

    Science.gov (United States)

    2017-06-01

    11  C.  TCI MISSIONS INTO HURRICANE JOAQUIN ............................. 13  III.  DATA AND METHODOLOGY ...October (Figure 12) indicated that the convection in Joaquin had become more organized with an enshrouded eye and rainbands spiraling outward on the...mission. Note that the intensity of Joaquin was still 75 kt at 0600 UTC 6 October (Table 1). 25 III. DATA AND METHODOLOGY A. TCI FIELD PROGRAM

  18. Geology of Paleozoic Rocks in the Upper Colorado River Basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, Excluding the San Juan Basin

    Science.gov (United States)

    Geldon, Arthur L.

    2003-01-01

    The geology of the Paleozoic rocks in the Upper Colorado River Basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis Program to provide support for hydrogeological interpretations. The study area is segmented by numerous uplifts and basins caused by folding and faulting that have recurred repeatedly from Precambrian to Cenozoic time. Paleozoic rocks in the study area are 0-18,000 feet thick. They are underlain by Precambrian igneous, metamorphic, and sedimentary rocks and are overlain in most of the area by Triassic formations composed mostly of shale. The overlying Mesozoic and Tertiary rocks are 0-27,000 feet thick. All Paleozoic systems except the Silurian are represented in the region. The Paleozoic rocks are divisible into 11 hydrogeologic units. The basal hydrogeologic unit consisting of Paleozoic rocks, the Flathead aquifer, predominantly is composed of Lower to Upper Cambrian sandstone and quartzite. The aquifer is 0-800 feet thick and is overlain gradationally to unconformably by formations of Cambrian to Mississippian age. The Gros Ventre confining unit consists of Middle to Upper Cambrian shale with subordinate carbonate rocks and sandstone. The confining unit is 0-1,100 feet thick and is overlain gradationally to unconformably by formations of Cambrian to Mississippian age. The Bighom aquifer consists of Middle Cambrian to Upper Ordovician limestone and dolomite with subordinate shale and sandstone. The aquifer is 0-3,000 feet thick and is overlain unconformably by Devonian and Mississipplan rocks. The Elbert-Parting confining unit consists of Lower Devonian to Lower Mississippian limestone, dolomite, sandstone, quartzite, shale, and anhydrite. It is 0-700 feet thick and is overlain conformably to unconformably by Upper Devonian and Mississippian rocks. The Madison aquifer consists of two zones of distinctly different lithology. The lower (Redwall-Leadville) zone

  19. Wetland management and rice farming strategies to decrease methylmercury bioaccumulation and loads from the Cosumnes River Preserve, California

    Science.gov (United States)

    Eagles-Smith, Collin A.; Ackerman, Joshua T.; Fleck, Jacob; Windham-Myers, Lisamarie; McQuillen, Harry; Heim, Wes

    2014-01-01

    We evaluated mercury (Hg) concentrations in caged fish (deployed for 30 days) and water from agricultural wetland (rice fields), managed wetland, slough, and river habitats in the Cosumnes River Preserve, California. We also implemented experimental hydrological regimes on managed wetlands and post-harvest rice straw management techniques on rice fields in order to evaluate potential Best Management Practices to decrease methylmercury bioaccumulation within wetlands and loads to the Sacramento-San Joaquin River Delta. Total Hg concentrations in caged fish were twice as high in rice fields as in managed wetland, slough, or riverine habitats, including seasonal managed wetlands subjected to identical hydrological regimes. Caged fish Hg concentrations also differed among managed wetland treatments and post-harvest rice straw treatments. Specifically, Hg concentrations in caged fish decreased from inlets to outlets in seasonal managed wetlands with either a single (fall-only) or dual (fall and spring) drawdown and flood-up events, whereas Hg concentrations increased slightly from inlets to outlets in permanent managed wetlands. In rice fields, experimental post-harvest straw management did not decrease Hg concentrations in caged fish. In fact, in fields in which rice straw was chopped and either disked into the soil or baled and removed from the fields, fish Hg concentrations increased from inlets to outlets and were higher than Hg concentrations in fish from rice fields subjected to the more standard post-harvest practice of simply chopping rice straw prior to fall flood-up. Finally, aqueous methylmercury (MeHg) concentrations and export were highly variable, and seasonal trends in particular were often opposite to those of caged fish. Aqueous MeHg concentrations and loads were substantially higher in winter than in summer, whereas caged fish Hg concentrations were relatively low in winter and substantially higher in summer. Together, our results highlight the

  20. An Introduction to the San Francisco Estuary Tidal Wetlands Restoration Series

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available Restoration of tidal wetlands may provide an important tool for improving ecological health and water management for beneficial uses of the San Francisco Estuary (hereafter “Estuary”. Given the large losses of tidal wetlands from San Francisco Bay and the Sacramento-San Joaquin Delta in the last 150 years, it seems logical to assume that restoring tidal wetlands will have benefits for a variety of aquatic and terrestrial native species that have declined during the same time period. However, many other changes have also occurred in the Estuary concurrent with the declines of native species. Other factors that might be important in species declines include the effects of construction of upstream dams, large and small water diversions within the Sacramento-San Joaquin Delta, agricultural pesticides, trace elements from industrial and agricultural activities, and invasions of alien species. Discussions among researchers, managers, and stakeholders have identified a number of uncertainties regarding the potential benefits of tidal wetland restoration. The articles of the Tidal Wetlands Restoration Series address four major issues of concern. Stated as questions, these are: 1. Will tidal wetland restoration enhance populations of native fishes? 2. Will wetland restoration increase rates of methylation of mercury? 3. Will primary production and other ecological processes in restored tidal wetlands result in net export of organic carbon to adjacent habitats, resulting in enhancement of the food web? Will the carbon produced contribute to the formation of disinfection byproducts when disinfected for use as drinking water? 4. Will restored tidal wetlands provide long-term ecosystem benefits that can be sustained in response to ongoing physical processes, including sedimentation and hydrodynamics? Reducing the uncertainty surrounding these issues is of critical importance because tidal wetland restoration is assumed to be a critical tool for

  1. Gonzo Strategies of Deceit: An Interview with Joaquin Segura

    Directory of Open Access Journals (Sweden)

    Brett W. Schultz

    2011-06-01

    Full Text Available The interview that follows is a dialogue between artist and gallerist with the intent of unearthing the artist’s working strategies for a general public. Joaquin Segura is at once an anomaly in Mexico’s contemporary art scene at the same time as he is one of the most emblematic representatives of a larger shift toward a post-national identity among its youngest generation of artists. If Mexico looks increasingly like a foreclosed home burning to the ground, Segura could likely be the one walking away, charred matchstick between thumb and forefinger and shit-eating grin on his face. His corrosive attacks on institutions, ideologies, and power reflect a deep general distrust of authority, increasingly evident within the work of younger Mexican artists. It is perhaps most directly the result of President Calderon’s deeply unpopular war against the cartels but no doubt equally the product of decades upon decades of rampant corruption and errant policy within Mexico.

  2. Implications of using on-farm flood flow capture to recharge groundwater and mitigate flood risks along the Kings River, CA.

    Science.gov (United States)

    Bachand, Philip A M; Roy, Sujoy B; Choperena, Joe; Cameron, Don; Horwath, William R

    2014-12-02

    The agriculturally productive San Joaquin Valley faces two severe hydrologic issues: persistent groundwater overdraft and flooding risks. Capturing flood flows for groundwater recharge could help address both of these issues, yet flood flow frequency, duration, and magnitude vary greatly as upstream reservoir releases are affected by snowpack, precipitation type, reservoir volume, and flood risks. This variability makes dedicated, engineered recharge approaches expensive. Our work evaluates leveraging private farmlands in the Kings River Basin to capture flood flows for direct and in lieu recharge, calculates on-farm infiltration rates, assesses logistics, and considers potential water quality issues. The Natural Resources Conservation Service (NRCS) soil series suggested that a cementing layer would hinder recharge. The standard practice of deep ripping fractured the layer, resulting in infiltration rates averaging 2.5 in d(-1) (6 cm d(-1)) throughout the farm. Based on these rates 10 acres are needed to infiltrate 1 cfs (100 m(3) h(-1)) of flood flows. Our conceptual model predicts that salinity and nitrate pulses flush initially to the groundwater but that groundwater quality improves in the long term due to pristine flood flows low in salts or nitrate. Flood flow capture, when integrated with irrigation, is more cost-effective than groundwater pumping.

  3. Delta Vegetation and Land Use [ds292

    Data.gov (United States)

    California Natural Resource Agency — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

  4. Demanda de irrigação da cultura da uva na Bacia do Rio São Francisco Irrigation demand for grape crop in San Francisco River Basin

    Directory of Open Access Journals (Sweden)

    Wallisson da S. Freitas

    2006-09-01

    Full Text Available Visando subsidiar o planejamento de projetos agrícolas para o dimensionamento de projetos de irrigação e a gestão de recursos hídricos, estimou-se e se espacializou a demanda de irrigação da videira (Vitis vinifera L., cv. Itália, na bacia do Rio São Francisco. Utilizaram-se séries históricas de dados de 81 estações climáticas distribuídas na bacia. Para cada estação calculou-se os valores, máximos diários e o total anual, da evapotranspiração de referência (ETo, da evapotranspiração da cultura (ETc, da demanda suplementar da cultura e da demanda suplementar de irrigação (este com eficiência de 70%. Com base nos resultados obtidos, concluiu-se que: (a a ETc máxima diária variou, em grande parte da bacia, de 4,5 a 5,7 mm d-1, tendo média anual de 943 mm; (b em média, a demanda anual suplementar da cultura foi 839,5 mm, equivalente a 103,5 mm inferior à ETc; (c o fato do sistema funcionar com 70% de eficiência, em vez de 90%, implica em acréscimo estimado de 18.808.755 m³ de água por ano, somente nas microrregiões de Juazeiro, BA e Petrolina, PE.The irrigation water demand of the grapevine (Vitis vinifera L. cv. Italy was estimated and spatialized in San Francisco River Basin, in order to subsidize the agricultural project planning and water resource management. Historical data series relative to 81 climatic stations distributed throughout the basin were used. The maximum daily values and the annual total values of the reference evapotranspiration (ETo, crop evapotranspiration (ETc, supplementary demand of the crop and the supplementary irrigation demand (70% efficiency were calculated for each station. According to the results, the following conclusions were drawn: (a in a large area of the basin, the maximum daily ETc varied from 4.5 to 5.7 mm d-1, with an annual mean of 943 mm; (b the supplementary annual demand of the crop averaged 839.5 mm, corresponding to 103.5 mm less than ETc; and (c the irrigation

  5. San Francisco Accelerator Conference

    International Nuclear Information System (INIS)

    Southworth, Brian

    1991-01-01

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  6. Use of geochemical biomarkers in bottom sediment to track oil from a spill, San Francisco Bay, California

    Science.gov (United States)

    Hostettler, F.D.; Rapp, J.B.; Kvenvolden, K.A.

    1992-01-01

    In April 1988, approximately 1500 m3 of a San Joaquin Valley crude oil were accidentally released from a Shell Oil Co. refinery near Martinez, Californa. The oil flowed into Carquinez Strait and Suisun Bay in northern San Francisco Bay Sediment and oil samples were collected within a week and analysed for geochemical marker compounds in order to track the molecular signature of the oil spill in the bottom sediment. Identification of the spilled oil in the sediment was complicated by the degraded nature of the oil and the similarity of the remaining, chromatographically resolvable constituents to those already present in the sediments from anthropogenic petroleum contamination, pyrogenic sources, and urban drainage. Ratios of hopane and sterane biomarkers, and of polycyclic aromatic hydrocarbons and their alkylated derivatives best identified the oil impingement. They showed the oil impact at this early stage to be surficial only, and to be patchy even within an area of heavy oil exposure.

  7. San Andreas Fault in the Carrizo Plain

    Science.gov (United States)

    2000-01-01

    The 1,200-kilometer (800-mile)San Andreas is the longest fault in California and one of the longest in North America. This perspective view of a portion of the fault was generated using data from the Shuttle Radar Topography Mission (SRTM), which flew on NASA's Space Shuttle last February, and an enhanced, true-color Landsat satellite image. The view shown looks southeast along the San Andreas where it cuts along the base of the mountains in the Temblor Range near Bakersfield. The fault is the distinctively linear feature to the right of the mountains. To the left of the range is a portion of the agriculturally rich San Joaquin Valley. In the background is the snow-capped peak of Mt. Pinos at an elevation of 2,692 meters (8,831 feet). The complex topography in the area is some of the most spectacular along the course of the fault. To the right of the fault is the famous Carrizo Plain. Dry conditions on the plain have helped preserve the surface trace of the fault, which is scrutinized by both amateur and professional geologists. In 1857, one of the largest earthquakes ever recorded in the United States occurred just north of the Carrizo Plain. With an estimated magnitude of 8.0, the quake severely shook buildings in Los Angeles, caused significant surface rupture along a 350-kilometer (220-mile) segment of the fault, and was felt as far away as Las Vegas, Nev. This portion of the San Andreas is an important area of study for seismologists. For visualization purposes, topographic heights displayed in this image are exaggerated two times.The elevation data used in this image was acquired by 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 Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60

  8. Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

    Science.gov (United States)

    Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler D.

    2005-01-01

    The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water

  9. Ground-Water Quality Data in the Central Eastside San Joaquin Basin 2006: Results from the California GAMA Program

    Science.gov (United States)

    Landon, Matthew K.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 1,695-square-mile Central Eastside study unit (CESJO) was investigated from March through June 2006 as part of the Statewide Basin Assessment Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The study was designed to provide a spatially unbiased assessment of raw ground-water quality within CESJO, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 78 wells in Merced and Stanislaus Counties. Fifty-eight of the 78 wells were selected using a randomized grid-based method to provide statistical representation of the study unit (grid wells). Twenty of the wells were selected to evaluate changes in water chemistry along selected lateral or vertical ground-water flow paths in the aquifer (flow-path wells). The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides and pesticide degradates], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3-trichloropropane (1,2,3-TCP)], inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements], radioactive constituents, and microbial indicators. Naturally occurring isotopes [tritium, carbon-14, and uranium isotopes and stable isotopes of hydrogen, oxygen, nitrogen, sulfur, and carbon], and dissolved noble and other gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected for approximately one-sixth of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control results showed that the environmental data were of good quality, with low bias and low variability, and resulted in censoring of less than 0.3 percent of the detections found in ground-water samples. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CADPH) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CADPH. VOCs and pesticides were detected in approximately half of the grid wells, and all detections in samples from CESJO wells were below health-based thresholds. All detections of nutrients and major elements in grid wells also were below health-based thresholds. Most detections of constituents of special interest, trace elements, and radioactive constituents in samples from grid wells were below health-based thresholds. Exceptions included two detections of arsenic that were above the USEPA maximum contaminant level (MCL-US), one detection of lead above the USEPA action level (AL-US), and one detection of vanadium and three detections of 1,2,3-TCP that were above the CADPH notification levels (NL-CA). All detections of radioactive constituents were below health-based thresholds, although fourteen samples had activities of radon-222 above the lower proposed MCL-US. Most of th

  10. Framework for Assessing Viability of Threatened and Endangered Chinook Salmon and Steelhead in the Sacramento–San Joaquin Basin

    Directory of Open Access Journals (Sweden)

    Steven T. Lindley

    2007-02-01

    Full Text Available Protected evolutionarily significant units (ESUs of salmonids require objective and measurable criteria for guiding their recovery. In this report, we develop a method for assessing population viability and two ways to integrate these population-level assessments into an assessment of ESU viability. Population viability is assessed with quantitative extinction models or criteria relating to population size, population growth rate, the occurrence of catastrophic declines, and the degree of hatchery influence. ESU viability is assessed by examining the number and distribution of viable populations across the landscape and their proximity to sources of catastrophic disturbance. Central Valley spring-run and winter-run Chinook salmon ESUs are not currently viable, according to the criteria-based assessment. In both ESUs, extant populations may be at low risk of extinction, but these populations represent a small portion of the historical ESUs, and are vulnerable to catastrophic disturbance. The winter-run Chinook salmon ESU, in the extreme case, is represented by a single population that spawns outside of its historical spawning range. We are unable to assess the status of the Central Valley steelhead ESU with our framework because almost all of its roughly 80 populations are classified as data deficient. The few exceptions are those populations with a closely associated hatchery, and the naturally-spawning fish in these streams are at high risk of extinction. Population monitoring in this ESU is urgently needed. Global and regional climate change poses an additional risk to the survival of salmonids in the Central Valley. A literature review suggests that by 2100, mean summer temperatures in the Central Valley region may increase by 2-8°C, precipitation will likely shift to more rain and less snow, with significant declines in total precipitation possible, and hydrographs will likely change, especially the the southern Sierra Nevada mountains. Warming at the lower end of the predicted range may allow spring-run Chinook salmon to persist in some streams, while making some currently utilized habitat inhospitable. At the upper end of the range of predicted warming, very little spring-run Chinook salmon habitat is expected to remain suitable. In spite of the precarious position of Central Valley salmonid ESUs, there are prospects for greatly improving their viability. Recovering Central Valley ESUs may require re-establishing populations where historical populations have been extirpated (e.g., upstream of major dams. Such major efforts should be focused on those watersheds that offer the best possibility of providing suitable habitat in a warmer future.

  11. Survival of patients with hepatocellular carcinoma in the San Joaquin Valley: a comparison with California Cancer Registry data.

    Science.gov (United States)

    Atla, Pradeep R; Sheikh, Muhammad Y; Mascarenhas, Ranjan; Choudhury, Jayanta; Mills, Paul

    2012-01-01

    Variation in the survival of patients with hepatocellular carcinoma (HCC) is related to racial differences, socioeconomic disparities and treatment options among different populations. A retrospective review of the data from medical records of patients diagnosed with HCC were analyzed at an urban tertiary referral teaching hospital and compared to patients in the California Cancer Registry (CCR) - a participant in the Survival Epidemiology and End Results (SEER)program of the National Cancer Institute (NCI). The main outcome measure was overall survival rates. 160 patients with the diagnosis of HCC (M/F=127/33), mean age 59.7±10 years, 32% white, 49% Hispanic, 12% Asian and 6% African American. Multivariate analysis identified tumor size, model for end-stage liver disease (MELD) score, portal vein invasion and treatment offered as the independent predictors of survival (p <0.05). Survival rates across racial groups were not statistically significant. 5.6% received curative treatments (orthotopic liver transplantation, resection, rediofrequency ablation) (median survival 69 months), 34.4% received nonsurgical treatments (trans-arterial chemoembolization, systemic chemotherapy) (median survival 9 months), while 60% received palliative or no treatment (median survival 3 months) (p <0.001). There was decreased survival in our patient population with HCC beyond 2 years. 60% of our study population received only palliative or no treatment suggesting a possible lack of awareness of chronic liver disease as well as access to appropriate surveillance modalities. Ethnic disparities such as Hispanic predominance in this study in contrast to the CCR/SEER database may have been a contributing factor for poorer outcome.

  12. California Environmental Vulnerability Assessment (CEVA) Score, San Joaquin Valley CA, 2013, UC Davis Center for Regional Change

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set is based on a three year study by the UC Davis Center for Regional Change, in affiliation with the Environmental Justice Project of the John Muir...

  13. Hazard and Pollution Hotspots of Environmental Screening Methods, San Joaquin Valley CA, 2013, Occidental College of Los Angeles

    Data.gov (United States)

    U.S. Environmental Protection Agency — This layer combines the highest values of the CES, CEVA, and EJSM layers for hazard and pollution which is the burden component of the models. These models combine...

  14. Toxicity of agricultural subsurface drainwater from the San Joaquin Valley, California to juvenile chinook salmon and striped bass

    Science.gov (United States)

    Saiki, Michael K.; Jennings, Mark R.; Wiedmeyer, Raymond H.

    1992-01-01

    Juvenile chinook salmon Oncorhynchus tshawytscha (40-50 mm total length, TL) and striped bass Morone saxatilis (30-40 mm TL) were exposed to serial dilutions (100, 50, 25, and 12.5%) of agricultural subsurface drainwater (WWD), reconstituted drainwater (RWWD), and reconstituted seawater (IO). Agricultural subsurface drainwater contained naturally elevated concentrations of major ions (such as sodium and sulfate) and trace elements (especially boron and selenium), RWWD contained concentrations of major ions that mimicked those in WWD but trace elements were not elevated, and IO contained concentrations of total dissolved salt that were similar to those in WWD and RWWD but chloride replaced sulfate as the dominant anion. After 28 d of static exposure, over 75% of the chinook salmon in 100% WWD had died, whereas none had died in other dilutions and water types. Growth of chinook salmon in WWD and RWWD, but not in IO, exhibited dilution responses. All striped bass died in 100% WWD within 23 d, whereas 19 of 20 striped bass had died in 100% RWWD after 28 d. In contrast, none died in 100% IO. Growth of striped bass was impaired only in WWD. Fish in WWD accumulated as much as 200 μg/g (dry-weight basis) of boron, whereas fish in control water accumulated less than 3.1 μg/g. Although potentially toxic concentrations of selenium occurred in WWD (geometric means, 158-218 μg/L), chinook salmon and striped bass exposed to this water type accumulated 5.7 μg Se/g or less. These findings indicate that WWD was toxic to chinook salmon and striped bass. Judging from available data, the toxicity of WWD was due primarily to high concentrations of major ions present in atypical ratios, to high concentrations of sulfate, or to both. High concentrations of boron and selenium also may have contributed to the toxicity of WWD, but their effects were not clearly delineated.

  15. 76 FR 41337 - Approval and Promulgation of Implementation Plans; California; 2008 San Joaquin Valley PM2.5

    Science.gov (United States)

    2011-07-13

    ... motor vehicles and engines. \\6\\ See CARB Resolution No. 07-28, September 27, 2007 with attachments and... implemented by the California Bureau of Automotive Repair (Smog Check improvements) and the California... SO 2 RACT requirements for electric generating units; (2) the deferral of the requirement to...

  16. 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 <10 microns (PM10) was associated with pulmonary valve stenosis (aOR4th Quartile=2.6; 95% CI: 1.2, 5.7) and perimembranous ventricular septal 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

  17. Traffic-Related Air Pollution and Risk of Preterm Birth in the San Joaquin Valley of California

    Science.gov (United States)

    Padula, Amy M.; Mortimer, Kathleen M.; Tager, Ira B.; Hammond, S. Katharine; Lurmann, Frederick W.; Yang, Wei; Stevenson, David K.; Shaw, Gary M.

    2014-01-01

    We evaluated associations between traffic-related air pollution during pregnancy and preterm birth in births in four counties in California during years 2000–2006. We used logistic regression to examine the association between the highest quartile of ambient air pollutants (carbon monoxide, nitrogen dioxide, particulate matter <10 and 2.5 μm) and traffic density during pregnancy and each of five levels of prematurity based on gestational age at birth (20–23, 24–27, 28–31, 32–33 and 34–36 weeks) versus term (37–42 weeks). We examined trimester averages and the last month and last 6 weeks of pregnancy. Models were adjusted for birth weight, maternal age, race/ethnicity, education, prenatal care and birth costs payment. Neighborhood socioeconomic status was evaluated as a potential effect modifier. There were increased odds ratios for early preterm birth for those exposed to the highest quartile of each pollutant during the second trimester and the end of pregnancy (adjusted odds ratios: 1.4– 2.8). Associations were stronger among mothers living in low socioeconomic status neighborhoods (adjusted odds ratios: 2.1–4.3). We observed exposure-response associations for multiple pollutant exposures and early preterm birth. Inverse associations during the first trimester were observed. The results confirm associations between traffic-related air pollution and prematurity, particularly among very early preterm births and low socioeconomic status neighborhoods. PMID:25453347

  18. Traffic-related air pollution and risk of preterm birth in the San Joaquin Valley of California.

    Science.gov (United States)

    Padula, Amy M; Mortimer, Kathleen M; Tager, Ira B; Hammond, S Katharine; Lurmann, Frederick W; Yang, Wei; Stevenson, David K; Shaw, Gary M

    2014-12-01

    To evaluate associations between traffic-related air pollution during pregnancy and preterm birth in births in four counties in California during years 2000 to 2006. We used logistic regression to examine the association between the highest quartile of ambient air pollutants (carbon monoxide, nitrogen dioxide, particulate matter prematurity based on gestational age at birth (20-23, 24-27, 28-31, 32-33, and 34-36 weeks) versus term (37-42 weeks). We examined trimester averages and the last month and the last 6 weeks of pregnancy. Models were adjusted for birthweight, maternal age, race/ethnicity, education, prenatal care, and birth costs payment. Neighborhood socioeconomic status (SES) was evaluated as a potential effect modifier. There were increased odds ratios (ORs) for early preterm birth for those exposed to the highest quartile of each pollutant during the second trimester and the end of pregnancy (adjusted OR, 1.4-2.8). Associations were stronger among mothers living in low SES neighborhoods (adjusted OR, 2.1-4.3). We observed exposure-response associations for multiple pollutant exposures and early preterm birth. Inverse associations during the first trimester were observed. The results confirm associations between traffic-related air pollution and prematurity, particularly among very early preterm births and low SES neighborhoods.

  19. Population structure of Xylella fastidiosa associated with almond leaf scorch disease in the San Joaquin Valley of California

    Science.gov (United States)

    Xylella fastidiosa (Xf) 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 Xf associated with ALS disease were evaluated. Strains isolated from two almond production si...

  20. 75 FR 10420 - Approval and Promulgation of Implementation Plans: 1-Hour Ozone Extreme Area Plan for San Joaquin...

    Science.gov (United States)

    2010-03-08

    ... Air Pollution Control District's Rule 9310, ``School Bus Fleets.'' DATES: Effective Date: This rule is... Pollution Control District (SJVAPCD or the District) in 2004 and amended in 2005. The 2004 SIP addresses CAA... day (tpd) and nitrogen oxides (NO X ) by 20 tpd and to approve SJVAPCD's Rule 9310, School Bus Fleets...

  1. Residential agricultural pesticide exposures and risks of selected birth defects among offspring in the San Joaquin Valley of California.

    Science.gov (United States)

    Carmichael, Suzan L; Yang, Wei; Roberts, Eric; Kegley, Susan E; Brown, Timothy J; English, Paul B; Lammer, Edward J; Shaw, Gary M

    2016-01-01

    We examined associations of birth defects with residential proximity to commercial agricultural pesticide applications in California. Subjects included 367 cases representing five types of birth defects and 785 nonmalformed controls born 1997 to 2006. Associations with any versus no exposure to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for covariates. Overall, 46% of cases and 38% of controls were classified as exposed to pesticides within a 500 m radius of mother's address during a 3-month periconceptional window. We estimated odds ratios (ORs) for 85 groups and 95 chemicals with five or more exposed cases and control mothers. Ninety-five percent confidence intervals (CI) excluded 1.0 for 11 ORs for groups and 22 ORs for chemicals, ranging from 1.9 to 3.1 for groups and 1.8 to 4.9 for chemicals except for two that were <1 (noted below). For groups, these ORs were for anotia/microtia (n = 95 cases) and dichlorophenoxy acids/esters and neonicotinoids; anorectal atresia/stenosis (n = 77) and alcohol/ethers and organophosphates (these ORs were < 1.0); transverse limb deficiencies (n = 59) and dichlorophenoxy acids/esters, petroleum derivatives, and triazines; and craniosynostosis (n = 79) and alcohol/ethers, avermectins, neonicotinoids, and organophosphates. For chemicals, ORs were: anotia/microtia and five pesticides from the groups dichlorophenoxy acids/esters, copper-containing compounds, neonicotinoids, organophosphates, and triazines; transverse limb deficiency and six pesticides - oxyfluorfen and pesticides from the groups copper-containing compounds, 2,6-dinitroanilines, neonicotinoids, petroleum derivatives and polyalkyloxy compounds; craniosynostosis and 10 pesticides - oxyfluorfen and pesticides from the groups alcohol/ethers, avermectins, n-methyl-carbamates, neonicotinoids, ogranophosphates (two chemicals), polyalkyloxy compounds (two chemicals), and pyrethroids; and congenital diaphragmatic hernia (n = 62) and a copper-containing compound. © 2015 Wiley Periodicals, Inc.

  2. SANS studies of polymers

    International Nuclear Information System (INIS)

    Wignall, G.D.

    1984-10-01

    Before small-angle neutron scattering (SANS), chain conformation studies were limited to light and small angle x-ray scattering techniques, usually in dilute solution. SANS from blends of normal and labeled molecules could give direct information on chain conformation in bulk polymers. Water-soluble polymers may be examined in H 2 O/D 2 O mixtures using contrast variation methods to provide further information on polymer structure. This paper reviews some of the information provided by this technique using examples of experiments performed at the National Center for Small-Angle Scattering Research (NCSASR)

  3. Remembering San Diego

    International Nuclear Information System (INIS)

    Chuyanov, V.

    1999-01-01

    After 6 years of existence the ITER EDA project in San Diego, USA, was terminated by desition of the US Congress. This article describes how nice it was for everybody as long as it lasted and how sad it is now

  4. Sediment transport in the San Francisco Bay Coastal System: An overview

    Science.gov (United States)

    Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,

    2013-01-01

    The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

  5. Spatial and temporal trends of contaminants in eggs of wading birds from San Francisco Bay, California

    Science.gov (United States)

    Hothem, R.L.; Roster, D.L.; King, K.A.; Keldsen, T.J.; Marois, Katherine C.; Wainwright, S.E.

    1995-01-01

    Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time, At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.

  6. River-floodplain Hydrologic Connectivity: Impact on Temporal and Spatial Floodplain Water Quality and Productivity Patterns

    Science.gov (United States)

    Gallo, E. L.; Ahearn, D.; Dahlgren, R. A.; Grosholz, E.

    2003-12-01

    Nutrient spiraling and cycling are critical processes for floodplain systems, but these have not been well studied in western North America. Floodplain production and function relies on the integrity of river-floodplain interactions, particularly during periods of hydrologic connectivity. The purpose of this study was to: (1) determine the importance of the timing and duration of river-floodplain hydrologic connectivity, (2) link flood event water quality to subsequent primary and secondary production, and (3) identify temporal and spatial patterns of floodplain production. The Cosumnes River watershed transports surface runoff and snowmelt from the Sierra Nevadas to the Sacramento-San Joaquin Delta. It is one of the few watersheds in California that has no major water diversions or impoundments; therefore the river responds to the natural watershed hydrology. The study site in southern Sacramento County is an unmanaged experimental floodplain, one of the few remaining floodplains in California. Weekly and flood-event water quality and macroinvertebrate sampling was conducted during the flood season from January through June in 2001 and 2002. Both water years were characterized by historically low river flows. On average, volatile suspended solids in the water column increased from 5 mg/l to 10 mg/l during early season periods of hydrologic connectivity (December - February), suggesting that during watershed flushing flood events, the river acts as a source of nutrients and organic matter to the floodplain. Following a flood event, invertebrate concentrations decreased on average from 26,000 individuals/m3 to 9,000 individuals/m3 for zooplankton and from 350 individuals/m2 to 65 individuals/m2 for benthic macro-invertebrate, suggesting a net dilution of invertebrates during flood events. Chlorophyll a (chl-a) levels were also diluted during flood events, on average from 25 ppb to 5 ppb. Zooplankton densities and chl-a levels quickly rose after flood events. On

  7. Colorado River Sewer System Joint Venture to Upgrade Wastewater System

    Science.gov (United States)

    SAN FRANCISCO -Today, the Colorado River Sewer System Joint Venture, located in Parker, Ariz. entered into an agreement with the EPA to upgrade their wastewater treatment system to meet stringent water quality standards. The cost of the upgrade is ap

  8. Hydrologic properties and ground-water flow systems of the Paleozoic rocks in the upper Colorado River basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, excluding the San Juan Basin

    Science.gov (United States)

    Geldon, Arthur L.

    2003-01-01

    The hydrologic properties and ground-water flow systems of Paleozoic sedimentary rocks in the Upper Colorado River Basin were investigated under the Regional Aquifer-System Analysis (RASA) program of the U.S. Geological Survey in anticipation of the development of water supplies from bedrock aquifers to fulfill the region's growing water demands. The study area, in parts of Arizona, Colorado, New Mexico, Utah, and Wyoming, covers about 100,000 square miles. It includes parts of four physiographic provinces--the Middle Rocky Mountains, Wyoming Basin, Southern Rocky Mountains, and Colorado Plateaus. A variety of landforms, including mountains, plateaus, mesas, cuestas, plains, badlands, and canyons, are present. Altitudes range from 3,100 to 14,500 feet. Precipitation is distributed orographically and ranges from less than 6 inches per year at lower altitudes to more than 60 inches per year in some mountainous areas. Most of the infrequent precipitation at altitudes of less than 6,000 feet is consumed by evapotranspiration. The Colorado and Green Rivers are the principal streams: the 1964-82 average discharge of the Colorado River where it leaves the Upper Colorado River Basin is 12,170 cubic feet per second (a decrease of 5,680 cubic feet per second since construction of Glen Canyon Dam in 1963). On the basis of their predominant lithologic and hydrologic properties, the Paleozoic rocks are classified into four aquifers and three confining units. The Flathead aquifer, Gros Ventre confining unit, Bighorn aquifer, Elbert-Parting confining unit, and Madison aquifer (Redwall-Leadville and Darwin-Humbug zones) make up the Four Corners aquifer system. A thick sequence, composed mostly of Mississippian and Pennsylvanian shale, anhydrite, halite, and carbonate rocks--the Four Corners confining unit (Belden-Molas and Paradox-Eagle Valley subunits)--overlies the Four Corners aquifer system in most areas and inhibits vertical ground-water flow between the Four Corners aquifer

  9. The effects of acidic mine drainage from historical mines in the Animas River watershed, San Juan County, Colorado—What is being done and what can be done to improve water quality?

    Science.gov (United States)

    Church, Stanley E.; Owen, Robert J.; Von Guerard, Paul; Verplanck, Philip L.; Kimball, Briant A.; Yager, Douglas B.

    2007-01-01

    Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas River watershed have shown that cost-effective remediation of mine sites must be carefully planned. of the more than 5400 mine, mill, and prospect sites in the watershed, ∼80 sites account for more than 90% of the metal loads to the surface drainages. Much of the low pH water and some of the metal loads are the result of weathering of hydrothermally altered rock that has not been disturbed by historical mining. Some stream reaches in areas underlain by hydrothermally altered rock contained no aquatic life prior to mining.Scientific studies of the processes and metal-release pathways are necessary to develop effective remediation strategies, particularly in watersheds where there is little land available to build mine-waste repositories. Characterization of mine waste, development of runoff profiles, and evaluation of ground-water pathways all require rigorous study and are expensive upfront costs that land managers find difficult to justify. Tracer studies of water quality provide a detailed spatial analysis of processes affecting surface- and ground-water chemistry. Reactive transport models were used in conjunction with the best state-of-the-art engineering solutions to make informed and cost-effective remediation decisions.Remediation of 23% of the high-priority sites identified in the watershed has resulted in steady improvement in water quality. More than $12 million, most contributed by private entities, has been spent on remediation in the Animas River watershed. The recovery curve for aquatic life in the Animas River system will require further documentation and long-term monitoring to evaluate the effectiveness of remediation projects implemented.

  10. Hydrological conditions and evaluation of sustainable groundwater use in the Sierra Vista Subwatershed, Upper San Pedro Basin, southeastern Arizona

    Science.gov (United States)

    Gungle, Bruce; Callegary, James B.; Paretti, Nicholas V.; Kennedy, Jeffrey R.; Eastoe, Christopher J.; Turner, Dale S.; Dickinson, Jesse; Levick, Lainie R.; Sugg, Zachary P.

    2016-08-18

    This study assessed progress toward achieving sustainable groundwater use in the Sierra Vista Subwatershed of the Upper San Pedro Basin, Arizona, through evaluation of 14 indicators of sustainable use. Sustainable use of groundwater in the Sierra Vista Subwatershed requires, at a minimum, a stable rate of groundwater discharge to, and thus base flow in, the San Pedro River. Many of the 14 indicators are therefore related to long-term or short-term effects on base flow and provide us with a means to evaluate groundwater discharge to and base flow in the San Pedro River. The indicators were based primarily on 10 to 20 years of data monitoring in the subwatershed, ending in 2012, and included subwatershedwide indicators, riparian-system indicators, San Pedro River indicators, and springs indicators.

  11. Crustal structure of the coastal and marine San Francisco Bay region, California

    Science.gov (United States)

    Parsons, Tom

    2002-01-01

    As of the time of this writing, the San Francisco Bay region is home to about 6.8 million people, ranking fifth among population centers in the United States. Most of these people live on the coastal lands along San Francisco Bay, the Sacramento River delta, and the Pacific coast. The region straddles the tectonic boundary between the Pacific and North American Plates and is crossed by several strands of the San Andreas Fault system. These faults, which are stressed by about 4 cm of relative plate motion each year, pose an obvious seismic hazard.

  12. 75 FR 38412 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2010-07-02

    ...-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA AGENCY: Coast Guard, DHS. ACTION: Temporary... waters of San Diego Bay in support of the San Diego POPS Fireworks. This safety zone is necessary to... San Diego POPS Fireworks, which will include fireworks presentations conducted from a barge in San...

  13. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Chinook Salmon.

    Science.gov (United States)

    1986-04-01

    fin is moderately forked; America are distributed from the adipose is stout and prominent; a Sacramento-San Joaquin River system free- tipoed flesh...downstream. Joaquin Rivers to spawn in 1953-83 The completed nest forms an oval de - (data from Taylor 1974; Reavis 1983; pression with a mound of gravel...warmwater fish produc- of engineering requirements and bio- tion and costs . Calif. Dep. Fish logical criteria. U.S. Army Corps Game, Inland Fish

  14. San Francisco folio, California, Tamalpais, San Francisco, Concord, San Mateo, and Haywards quadrangles

    Science.gov (United States)

    Lawson, Andrew Cowper

    1914-01-01

    The five sheets of the San Francisco folio the Tamalpais, Ban Francisco, Concord, Ban Mateo, and Haywards sheets map a territory lying between latitude 37° 30' and 38° and longitude 122° and 122° 45'. Large parts of four of these sheets cover the waters of the Bay of San Francisco or of the adjacent Pacific Ocean. (See fig. 1.) Within the area mapped are the cities of San Francisco, Oakland, Berkeley, Alameda, Ban Rafael, and San Mateo, and many smaller towns and villages. These cities, which have a population aggregating about 750,000, together form the largest and most important center of commercial and industrial activity on the west coast of the United States. The natural advantages afforded by a great harbor, where the railways from the east meet the ships from all ports of the world, have determined the site of a flourishing cosmopolitan, commercial city on the shores of San Francisco Bay. The bay is encircled by hilly and mountainous country diversified by fertile valley lands and divides the territory mapped into two rather contrasted parts, the western part being again divided by the Golden Gate. It will therefore be convenient to sketch the geographic features under four headings (1) the area east of San Francisco Bay; (2) the San Francisco Peninsula; (3) the Marin Peninsula; (4) San Francisco Bay. (See fig. 2.)

  15. The Role of Tidal Marsh Restoration in Fish Management in the San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Bruce Herbold

    2014-03-01

    Full Text Available   Tidal marsh restoration is an important management issue in the San Francisco Estuary (estuary. Restoration of large areas of tidal marsh is ongoing or planned in the lower estuary (up to 6,000 ha, Callaway et al. 2011. Large areas are proposed for restoration in the upper estuary under the Endangered Species Act biological opinions (3,237 ha and the Bay Delta Conservation Plan (26,305 ha. In the lower estuary, tidal marsh has proven its value to a wide array of species that live within it (Palaima 2012. In the Sacramento–San Joaquin Delta (Delta, one important function ascribed to restoration of freshwater tidal marshes is that they make large contributions to the food web of fish in open waters (BDCP 2013. The Ecosystem Restoration Program ascribed a suite of ecological functions to tidal marsh restoration, including habitat and food web benefits to native fish (CDFW 2010. This background was the basis for a symposium, Tidal Marshes and Native Fishes in the Delta: Will Restoration Make a Difference? held at the University of California, Davis, on June 10, 2013. This paper summarizes conclusions the authors drew from the symposium. 

  16. Wetland Flow and Salinity Budgets and Elements of a Decision Support System toward Implementation of Real-Time Seasonal Wetland Salinity Management

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, N.W.T.; Ortega, R.; Rahilly, P.; Johnson, C.B.

    2011-12-17

    The project has provided science-based tools for the long-term management of salinity in drainage discharges from wetlands to the San Joaquin River. The results of the project are being used to develop best management practices (BMP) and a decision support system to assist wetland managers adjust the timing of salt loads delivered to the San Joaquin River during spring drawdown. Adaptive drainage management scheduling has the potential to improve environmental compliance with salinity objectives in the Lower San Joaquin River by reducing the frequency of violation of Vernalis salinity standards, especially in dry and critically dry years. The paired approach to project implementation whereby adaptively managed and traditional practices were monitored in a side-by-side fashion has provided a quantitative measure of the impacts of the project on the timing of salt loading to the San Joaquin River. The most significant accomplishments of the project has been the technology transfer to wetland biologists, ditch tenders and water managers within the Grasslands Ecological Area. This “learning by doing” has build local community capacity within the Grassland Water District and California Department of Fish and Game providing these institutions with new capability to assess and effectively manage salinity within their wetlands while simultaneously providing benefits to salinity management of the San Joaquin River.

  17. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

    One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.

  18. Metals transport in the Sacramento River, California, 1996-1997; Volume 2: Interpretation of metal loads

    Science.gov (United States)

    Alpers, Charles N.; Antweiler, Ronald C.; Taylor, Howard E.; Dileanis, Peter D.; Domagalski, Joseph L.

    2000-01-01

    Metals transport in the Sacramento River, northern California, from July 1996 to June 1997 was evaluated in terms of metal loads from samples of water and suspended colloids that were collected on up to six occasions at 13 sites in the Sacramento River Basin. Four of the sampling periods (July, September, and November 1996; and May-June 1997) took place during relatively low-flow conditions and two sampling periods (December 1996 and January 1997) took place during high-flow and flooding conditions, respectively. This study focused primarily on loads of cadmium, copper, lead, and zinc, with secondary emphasis on loads of aluminum, iron, and mercury.Trace metals in acid mine drainage from abandoned and inactive base-metal mines, in the East and West Shasta mining districts, enter the Sacramento River system in predominantly dissolved form into both Shasta Lake and Keswick Reservoir. The proportion of trace metals that was dissolved (as opposed to colloidal) in samples collected at Shasta and Keswick dams decreased in the order zinc ≈ cadmium > copper > lead. At four sampling sites on the Sacramento River--71, 256, 360, and 412 kilometers downstream of Keswick Dam--trace-metal loads were predominantly colloidal during both high- and low-flow conditions. The proportion of total cadmium, copper, lead, and zinc loads transported to San Francisco Bay and the Sacramento-San Joaquin Delta estuary (referred to as the Bay-Delta) that is associated with mineralized areas was estimated by dividing loads at Keswick Dam by loads 412 kilometers downstream at Freeport and the Yolo Bypass. During moderately high flows in December 1996, mineralization-related total (dissolved + colloidal) trace-metal loads to the Bay-Delta (as a percentage of total loads measured downstream) were cadmium, 87 percent; copper, 35 percent; lead, 10 percent; and zinc, 51 percent. During flood conditions in January 1997 loads were cadmium, 22 percent; copper, 11 percent; lead, 2 percent; and zinc, 15

  19. Hydrology of the middle San Pedro area, southeastern Arizona

    Science.gov (United States)

    Cordova, Jeffrey T.; Dickinson, Jesse; Beisner, Kimberly R.; Hopkins, Candice B.; Kennedy, Jeffrey R.; Pool, Donald R.; Glenn, Edward P.; Nagler, Pamela L.; Thomas, Blakemore E.

    2015-05-05

    In the middle San Pedro Watershed in southeastern Arizona, groundwater is the primary source of water supply for municipal, domestic, industrial, and agricultural use. The watershed comprises two smaller subareas, the Benson subarea and the Narrows-Redington subarea. Early 21st century projections for heavy population growth in the watershed have not yet become a reality, but increased groundwater withdrawals could have undesired consequences - such as decreased base flow to the San Pedro River, and groundwater-level declines - that would lead to the need to deepen existing wells. This report describes the hydrology, hydrochemistry, water quality, and development of a groundwater budget for the middle San Pedro Watershed, focusing primarily on the elements of groundwater movement that could be most useful for the development of a groundwater modelPrecipitation data from Tombstone, Arizona, and base flow at the stream-gaging station on the San Pedro River at Charleston both show relatively dry periods during the 1960s through the mid-1980s and in the mid-1990s to 2009, and wetter periods from the mid-1980s through the mid-1990s. Water levels in four out of five wells near the mountain fronts show cyclical patterns of recharge, with rates of recharge greatest in the early 1980s through the mid-1990s. Three wells near the San Pedro River recorded their lowest levels during the 1950s to the mid-1960s. The water-level record from one well, completed in the confined part of the coarse-grained lower basin fill, showed a decline of approximately 21 meters.Annual flow of the San Pedro River, measured at the Charleston and Redington gages, has decreased since the 1940s. The median annual streamflow and base flow at the gaging station on the river near Tombstone has decreased by 50 percent between the periods 1968–1986 and 1997–2009. Estimates of streamflow infiltration along the San Pedro River during 1914–2009 have decreased 44 percent, with the largest decreases in

  20. 76 FR 1386 - Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2011-01-10

    ...-AA00 Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA AGENCY: Coast... zone on the navigable waters of San Diego Bay in San Diego, CA in support of the Centennial of Naval... February 12, 2010, the Centennial of Naval Aviation Kickoff will take place in San Diego Bay. In support of...

  1. Community-based Flood Risk Assessment using GIS for the Town of San Sebastian, Guatemala

    NARCIS (Netherlands)

    Peters-Guarin, G.; van Westen, C.J.; Montoya, L.

    2005-01-01

    The municipality of San Sebastián, considered one of the most prone to natural hazards in Guatemala, was selected as one of the pilot areas of the UNESCO program on “Capacity Building for Natural Disaster Reduction‿. The town is located within the Samalá basin, near the active channel of the river,

  2. Hydrological Effects of Historic Rainfall on the Waccamaw River

    Science.gov (United States)

    Jolly, J.; Bao, S.

    2017-12-01

    This study focuses on the overall water budget of the Waccamaw River during and after a historic rainfall event related to Hurricane Joaquin, producing a 1000-year rainfall event. While rainfall is the only input, it enters the basin through various means. Some rainwater enters the soil as soil moisture while rainfall also goes underground and enters the river channels from underground, which is defined as bucket in. Over time, the rainfall was removed from the river site through various natural processes. Those processes, including evaporation, soil storage as soil moisture, discharge runoff through the river channel, among others, were modeled and validated against the USGS gauge stations. The validated model results were then used to estimate the hydrological response of the Waccamaw River to the rainfall event and determine the overall water budget. The experiment was completed using a WRF-Hydro modeling system for the purposes of weather forecasting and meteorological analysis. Upon completion of the data analysis, the WRF-Hydro model result showed that large amounts of rainfall were variously dispersed through the aforementioned areas. It was determined that after entering the soil rainfall predominantly left the river basin by discharge, while evaporation accounted for the second most common destination of rainfall. Base flow also accounted for a destination of rainfall, though not as much as those previously mentioned.

  3. 78 FR 53243 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-08-29

    ... this rule because the logistical details of the San Diego Bay triathlon swim were not finalized nor... September 22, 2013. (c) Definitions. The following definition applies to this section: Designated...

  4. Using 10Be erosion rates and fluvial channel morphology to constrain fault throw rates in the southwestern Sacramento River Valley, California, USA

    Science.gov (United States)

    Cyr, A. J.

    2013-12-01

    The Sacramento - San Joaquin River Delta, California, USA, is a critical region for California water resources, agriculture, and threatened or endangered species. This landscape is affected by an extensive set of levees that enclose artificial islands created for agricultural use. In addition to their importance for sustaining agriculture, this levee system also supports extensive transport and power transmission infrastructure and urban/suburban development. These levees are susceptible to damage from even moderate ground shaking by either a large earthquake on one of the high-activity faults in the nearby San Francisco Bay region, or even a moderate earthquake on one of the low-activity faults in the Delta region itself. However, despite this danger the earthquake hazards in this region are poorly constrained due to our lack of understanding of faults in and near the Delta region. As part of an effort to better constrain the seismic hazard associated with known, but poorly constrained, faults in the region, a geomorphic analysis of the Dunnigan Hills, northwest of Woodland, CA, is being combined with cosmogenic 10Be catchment-averaged erosion rates. The Dunnigan Hills are a low-relief (maximum elevation 87 m) landscape generated by fault-bend folding above the west-vergent Sweitzer reverse fault that soles into a blind east-vergent reverse fault. These faults have been imaged by seismic reflection data, and local microseismicity indicates that this system is actively propagating to the east. However, the throw rates on the faults in this system remain unconstrained, despite the potential for significant shaking such as that experienced in the nearby April, 1892 earthquake sequence between Winters and Vacaville, Ca, ~25 km to the south, which has been estimated at magnitude 6.0 or greater. Geomorphic and cosmogenic 10Be analyses from 12 catchments draining the eastern flank of the Dunnigan Hills will be used to infer vertical rock uplift rates to better constrain

  5. Coherence between coastal and river flooding along the California coast

    Science.gov (United States)

    Odigie, Kingsley O.; Warrick, Jonathan

    2018-01-01

    Water levels around river mouths are intrinsically determined by sea level and river discharge. If storm-associated coastal water-level anomalies coincide with extreme river discharge, landscapes near river mouths will be flooded by the hydrodynamic interactions of these two water masses. Unfortunately, the temporal relationships between ocean and river water masses are not well understood. The coherence between extreme river discharge and coastal water levels at six California river mouths across different climatic and geographic regions was examined. Data from river gauges, wave buoys, and tide gauges from 2007 to 2014 were integrated to investigate the relationships between extreme river discharge and coastal water levels near the mouths of the Eel, Russian, San Lorenzo, Ventura, Arroyo Trabuco, and San Diego rivers. Results indicate that mean and extreme coastal water levels during extreme river discharge are significantly higher compared with background conditions. Elevated coastal water levels result from the combination of nontidal residuals (NTRs) and wave setups. Mean and extreme (>99th percentile of observations) NTRs are 3–20 cm and ∼30 cm higher during extreme river discharge conditions, respectively. Mean and extreme wave setups are up to 40 cm and ∼20–90 cm higher during extreme river discharge than typical conditions, respectively. These water-level anomalies were generally greatest for the northern rivers and least for the southern rivers. Time-series comparisons suggest that increases in NTRs are largely coherent with extreme river discharge, owing to the low atmospheric pressure systems associated with storms. The potential flooding risks of the concurrent timing of these water masses are tempered by the mixed, semidiurnal tides of the region that have amplitudes of 2–2.5 m. In summary, flooding hazard assessments for floodplains near California river mouths for current or future conditions with sea-level rise should include the temporal

  6. Mercury-contaminated hydraulic mining debris in San Francisco Bay

    Science.gov (United States)

    Bouse, Robin M.; Fuller, Christopher C.; Luoma, Samuel N.; Hornberger, Michelle I.; Jaffe, Bruce E.; Smith, Richard E.

    2010-01-01

    The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercurycontaminated sediment created by hydraulic gold mining in the Sierra Nevada, between 1852 and 1884, ended up over 250 kilometers (km) away in San Francisco Bay; an example of the far-reaching extent of contamination from such activities.

  7. Hydrologic assessment and numerical simulation of groundwater flow, San Juan Mine, San Juan County, New Mexico, 2010–13

    Science.gov (United States)

    Stewart, Anne M.

    2018-04-03

    Shumway Arroyo alluvium after 1,320 years and from there to the San Juan River alluvium after 1,520 years or from southernmost CCB repositories directly to the San Juan River alluvium after 2,400 years after the cessation of mining.

  8. Synthesis of studies in the fall low-salinity zone of the San Francisco Estuary, September-December 2011

    Science.gov (United States)

    Brown, Larry R.; Baxter, Randall; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven; Erickson, Gregg; Feyrer, Frederick; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce; Kirsch, Joseph; Mueller-Solger, Anke; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Van Nieuwenhuyse, Erwin

    2014-01-01

    In fall 2011, a large-scale investigation (fall low-salinity habitat investigation) was implemented by the Bureau of Reclamation in cooperation with the Interagency Ecological Program to explore hypotheses about the ecological role of low-salinity habitat in the San Francisco Estuary—specifically, hypotheses about the importance of fall low-salinity habitat to the biology of delta smelt Hypomesus transpacificus, a species endemic to the San Francisco Estuary and listed as threatened or endangered under federal and state endangered species legislation. The Interagency Ecological Program is a consortium of 10 agencies that work together to develop a better understanding of the ecology of the Estuary and the effects of the State Water Project and Federal Central Valley Project operations on the physical, chemical, and biological conditions of the San Francisco Estuary. The fall low-salinity habitat investigation constitutes one of the actions stipulated in the Reasonable and Prudent Alternative issued with the 2008 Biological Opinion of the U.S. Fish and Wildlife Service, which called for adaptive management of fall Sacramento-San Joaquin Delta outflow following “wet” and “above normal” water years to alleviate jeopardy to delta smelt and adverse modification of delta smelt critical habitat. The basic hypothesis of the adaptive management of fall low-salinity habitat is that greater outflows move the low-salinity zone (salinity 1–6), an important component of delta smelt habitat, westward and that moving the low-salinity zone westward of its position in the fall of recent years will benefit delta smelt, although the specific mechanisms providing such benefit are uncertain. An adaptive management plan was prepared to guide implementation of the adaptive management of fall low-salinity habitat and to reduce uncertainty. This report has three major objectives:

  9. Charles River

    Science.gov (United States)

    Information on the efforts of the US EPA, the Commonwealth of Massachusetts, the municipalities within the Charles River Watershed and nongovernmental organizations to improve the water quality of the Charles River.

  10. Marketing San Juan Basin gas

    International Nuclear Information System (INIS)

    Posner, D.M.

    1988-01-01

    Marketing natural gas produced in the San Juan Basin of New Mexico and Colorado principally involves four gas pipeline companies with significant facilities in the basin. The system capacity, transportation rates, regulatory status, and market access of each of these companies is evaluated. Because of excess gas supplies available to these pipeline companies, producers can expect improved take levels and prices by selling gas directly to end users and utilities as opposed to selling gas to the pipelines for system supply. The complexities of transporting gas today suggest that the services of an independent gas marketing company may be beneficial to smaller producers with gas supplies in the San Juan Basin

  11. Update: San Andreas Fault experiment

    Science.gov (United States)

    Christodoulidis, D. C.; Smith, D. E.

    1984-01-01

    Satellite laser ranging techniques are used to monitor the broad motion of the tectonic plates comprising the San Andreas Fault System. The San Andreas Fault Experiment, (SAFE), has progressed through the upgrades made to laser system hardware and an improvement in the modeling capabilities of the spaceborne laser targets. Of special note is the launch of the Laser Geodynamic Satellite, LAGEOS spacecraft, NASA's only completely dedicated laser satellite in 1976. The results of plate motion projected into this 896 km measured line over the past eleven years are summarized and intercompared.

  12. Vegetation - San Felipe Valley [ds172

    Data.gov (United States)

    California Natural Resource Agency — This Vegetation Map of the San Felipe Valley Wildlife Area in San Diego County, California is based on vegetation samples collected in the field in 2002 and 2005 and...

  13. San Francisco Bay Water Quality Improvement Fund

    Science.gov (United States)

    EPAs grant program to protect and restore San Francisco Bay. The San Francisco Bay Water Quality Improvement Fund (SFBWQIF) has invested in 58 projects along with 70 partners contributing to restore wetlands, water quality, and reduce polluted runoff.,

  14. The San Bernabe power substation; La subestacion San Bernabe

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Sanudo, Andres D. [Luz y Fuerza del Centro, Mexico, D. F. (Mexico)

    1997-12-31

    The first planning studies that gave rise to the San Bernabe substation go back to year 1985. The main circumstance that supports this decision is the gradual restriction for electric power generation that has been suffering the Miguel Aleman Hydro System, until its complete disappearance, to give priority to the potable water supply through the Cutzamala pumping system, that feeds in an important way Mexico City and the State of Mexico. In this document the author describes the construction project of the San Bernabe Substation; mention is made of the technological experiences obtained during the construction and its geographical location is shown, as well as the one line diagram of the same [Espanol] Los primeros estudios de planeacion que dieron origen a la subestacion San Bernabe se remontan al ano de 1985. La circunstancia principal que soporta esta decision es la restriccion paulatina para generar energia que ha venido experimentando el Sistema Hidroelectrico Miguel Aleman, hasta su desaparicion total, para dar prioridad al suministro de agua potable por medio del sistema de bombeo Cutzamala, que alimenta en forma importante a la Ciudad de Mexico y al Estado de Mexico. En este documento el autor describe el proyecto de construccion de la subestacion San Bernabe; se mencionan las experiencias tecnologicas obtenidas durante su construccion y se ilustra su ubicacion geografica, asi como un diagrama unifilar de la misma

  15. 33 CFR 165.754 - Safety Zone: San Juan Harbor, San Juan, PR.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone: San Juan Harbor, San Juan, PR. 165.754 Section 165.754 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Zone: San Juan Harbor, San Juan, PR. (a) Regulated area. A moving safety zone is established in the...

  16. 76 FR 45693 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2011-08-01

    ...-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA AGENCY: Coast Guard, DHS. ACTION: Temporary... San Diego Bay in support of the San Diego POPS Fireworks. This safety zone is necessary to provide for... of the waterway during scheduled fireworks events. Persons and vessels will be prohibited from...

  17. 77 FR 26578 - Draft Environmental Impact Statement/Environmental Impact Report and Notice of Public Meeting for...

    Science.gov (United States)

    2012-05-04

    ...The Bureau of Reclamation and the San Joaquin River Exchange Contractors Water Authority have made available for public review and comment the joint draft environmental impact statement/environmental impact report (Draft EIS/EIR) for the Water Transfer Program, 2014- 2038. The proposed new transfer program would provide for the transfer and/or exchange of up to 150,000 acre-feet of substitute water from the San Joaquin River Exchange Contractors Water Authority to several potential users over a 25-year timeframe (water service years 2014- 2038).

  18. Estimating natural recharge in San Gorgonio Pass watersheds, California, 1913–2012

    Science.gov (United States)

    Hevesi, Joseph A.; Christensen, Allen H.

    2015-12-21

    A daily precipitation-runoff model was developed to estimate spatially and temporally distributed recharge for groundwater basins in the San Gorgonio Pass area, southern California. The recharge estimates are needed to define transient boundary conditions for a groundwater-flow model being developed to evaluate the effects of pumping and climate on the long-term availability of groundwater. The area defined for estimating recharge is referred to as the San Gorgonio Pass watershed model (SGPWM) and includes three watersheds: San Timoteo Creek, Potrero Creek, and San Gorgonio River. The SGPWM was developed by using the U.S. Geological Survey INFILtration version 3.0 (INFILv3) model code used in previous studies of recharge in the southern California region, including the San Gorgonio Pass area. The SGPWM uses a 150-meter gridded discretization of the area of interest in order to account for spatial variability in climate and watershed characteristics. The high degree of spatial variability in climate and watershed characteristics in the San Gorgonio Pass area is caused, in part, by the high relief and rugged topography of the area.

  19. An Archeological Survey of the San Diego River

    Science.gov (United States)

    1975-08-27

    This site wr.e located where Friars Road has been greatly widened and apartments and a gas station have been built. An area of shell and flake soattei...were found in a group of large boulders • with midden on the north side of El Nopal Road, in a vacant lot east of & residence (Pigure 31). Mano

  20. Tijuana River Flood Control Project, San Diego County, California.

    Science.gov (United States)

    1976-05-20

    presence of historical and archeological resoureces in the proposed project area. His letter of August 1, 1973 (see appendix) indicated that no state... human misery among those directly affected. Those impacts will be pert of the permanent and disastrous legacy of the "Recommended Plan" (Alternative Ill...of citizens; and general human misery among those directly affected. Those impacts will be part of the permanent and disastrous legacy of the

  1. Mercury in San Francisco Bay forage fish

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Ben K., E-mail: ben@sfei.or [San Francisco Estuary Institute, 7770 Pardee Lane, Oakland, CA 94621 (United States); Jahn, Andrew, E-mail: andyjahn@mac.co [1000 Riverside Drive, Ukiah, CA 95482 (United States)

    2010-08-15

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 {mu}g g{sup -1} (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  2. Mercury in San Francisco Bay forage fish

    International Nuclear Information System (INIS)

    Greenfield, Ben K.; Jahn, Andrew

    2010-01-01

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 μg g -1 (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  3. ASTER Flyby of San Francisco

    Science.gov (United States)

    2002-01-01

    The Advanced Spaceborne Thermal Emission and Reflection radiometer, ASTER, is an international project: the instrument was supplied by Japan's Ministry of International Trade and Industry. A joint US/Japan science team developed algorithms for science data products, and is validating instrument performance. With its 14 spectral bands, extremely high spatial resolution, and 15 meter along-track stereo capability, ASTER is the zoom lens of the Terra satellite. The primary mission goals are to characterize the Earth's surface; and to monitor dynamic events and processes that influence habitability at human scales. ASTER's monitoring and mapping capabilities are illustrated by this series of images of the San Francisco area. The visible and near infrared image reveals suspended sediment in the bays, vegetation health, and details of the urban environment. Flying over San Francisco (3.2MB) (high-res (18.3MB)), we see the downtown, and shadows of the large buildings. Past the Golden Gate Bridge and Alcatraz Island, we cross San Pablo Bay and enter Suisun Bay. Turning south, we fly over the Berkeley and Oakland Hills. Large salt evaporation ponds come into view at the south end of San Francisco Bay. We turn northward, and approach San Francisco Airport. Rather than landing and ending our flight, we see this is as only the beginning of a 6 year mission to better understand the habitability of the world on which we live. For more information: ASTER images through Visible Earth ASTER Web Site Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  4. Connecting Past to Present and Watersheds to Ocean: Modeling 165 Years of Incremental Changes to Flows into the San Francisco Bay Delta System

    Science.gov (United States)

    MacVean, L. J.; Thompson, S. E.; Huttom, P. H.; Sivapalan, M.

    2016-02-01

    California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. Managing and allocating this resource is a complex feat of economics, politics, and engineering, made increasingly contentious by the ongoing drought. The objective of this research is to augment the scientific foundation of management decisions by addressing the question of how flows into the Delta have evolved in response to human intervention since 1850. In particular, quantifying the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development is a key ambition. This approach emphasizes the built environment, which is subject to the local regulatory framework, rather than climate change, which is generally considered immovable without united global effort. This work encompasses the creation of a hydrologic model representing the watersheds of the San Francisco Bay-Delta system, and quantifies the impacts of changes in land use and the gradual construction of levees, reservoirs, and diversion infrastructure. The model is run using the same climatological forcing at each level of development, thus elucidating the effects of local anthropogenic activity on the Delta and the inflows to the San Francisco Bay estuary. Our results provide a timeline of change, giving decision-makers a scientifically established baseline to aid in the sustainable management of the Bay-Delta system.

  5. 78 FR 19103 - Safety Zone; Spanish Navy School Ship San Sebastian El Cano Escort; Bahia de San Juan; San Juan, PR

    Science.gov (United States)

    2013-03-29

    ...-AA00 Safety Zone; Spanish Navy School Ship San Sebastian El Cano Escort; Bahia de San Juan; San Juan... temporary moving safety zone on the waters of Bahia de San Juan during the transit of the Spanish Navy... Channel entrance, and to protect the high ranking officials on board the Spanish Navy School Ship San...

  6. The sinking of the El Faro: predicting real world rogue waves during Hurricane Joaquin.