Geology topics

Kelly R. McPherson

Publications and source records attributed to Kelly R. McPherson.

9 recordsLinked to original sources

USGS2021

Precipitation-runoff processes in the Merced River Basin, Central California, with prospects for streamflow predictability, water years 1952–2013

The U.S. Geological Survey, in cooperation with the California Department of Water Resources (DWR), has constructed a new spatially detailed Precipitation-Runoff Modeling System (PRMS) model for the Merced River Basin, California, which is a tributary of the San Joaquin River in California. Operated through an Object User Interface (OUI) with Ensemble Streamflow Prediction (ESP) and daily climate distribution preprocessing functionality, the model is calibrated primarily to simulate (and eventually, forecast) year-to-year variations of inflows to Lake McClure during the critical April–July snowmelt season. The model is intended to become part of a suite of methods used by DWR for estimating daily streamflow from the Merced River Basin, especially during the snowmelt season. This study describes the results of the application of an analysis tool that simulates responses to climate and land-use variations at a higher spatial resolution than previously available to DWR. A geographic information system was used to delineate the model domain, that is, areas draining to a single outlet at U.S. Geological Survey streamflow-gaging station 11270900, Merced River below Merced Falls Dam, near Snell, CA (also known as California Data Exchange Center station MRC), and subdrainage areas, including four draining to internal gages used as calibration targets. Using this delineation, three contiguous subbasins were recognized and, along with the model domain and nested calibration targets, are the simulation units evaluated in this report. An auto-calibration tool, LUCA (Let Us CAlibrate), was used for each calibration node, from headwaters to basin outlet, and then parameters were manually adjusted to complete the calibration. The main objective was to match April–July snowmelt seasonal discharge values of simulated streamflow to observed (measured or reconstructed) discharge values. Calibration or validation periods used site-specific streamflows—mostly from October 1, 1988, through September 30, 2013—but differed according to the period-of-record available for the measurements collected at internal gages or reconstructed flows for the single outlet. The accuracy of the Merced PRMS streamflow simulations varied seasonally, as compared to observed values. Based on statistical results, the Merced PRMS model satisfactorily simulated snowmelt seasonal streamflows. April–July calibrations for all areas had small negative bias (not greater than 7 percent) and low relative error (less than 8 percent). Less satisfactory performance for other seasons was attributed to several factors: (1) high uncertainty in low or zero flows in summer and fall, (2) lack of accounting for basin withdrawals and anthropogenic water use, (3) unavailability and (or) inaccuracy of observed (measured) meteorological input data, and (4) uncertainty in reconstructed streamflow data. With some additional refinement, the Merced PRMS model may be used for forecasting seasonal and longer-term streamflow variations; evaluating forecasted and past climate and land cover changes; providing water-resource managers with a consistent and documented method for estimating streamflow at ungaged sites within the basin; and aiding environmental studies, hydraulic design, water management, and water-quality projects in the Merced River Basin.

California↗

USGS2018

Geologic, hydrologic, and water-quality data from multiple-well monitoring sites in the Bunker Hill and Yucaipa Groundwater Subbasins, San Bernardino County, California, 1974–2016

In 1974, the U.S. Geological Survey (USGS), in cooperation with the San Bernardino Valley Municipal Water District, initiated a study to assess the regional groundwater resources in the Bunker Hill Subbasin of the Upper Santa Ana Valley Groundwater Basin in San Bernardino County, California. The study area expanded east into the Yucaipa Subbasin in 1996. This report compiles the geologic (borehole lithology and geophysical logs) and hydrologic (water-quality and water-level) data collected from 1974–2016 for 11 multiple-well monitoring sites (48 individual wells) constructed by the USGS in the Bunker Hill (7 sites) and Yucaipa (4 sites) Groundwater Subbasins. Approximately 240 water-quality samples from the 11 sites were analyzed for constituents including major and minor ions, nutrients, selected trace elements, organic wastewater compounds (OWCs), volatile organic compounds (VOCs), pesticides and pesticide degradates, the stable isotopes of hydrogen, oxygen, and nitrogen, and the radiogenic isotopes of tritium and carbon-14. All environmental data associated with these sites are available on the project web page for the San Bernardino Optimal Basin Management study ( https://ca.water.usgs.gov/sanbern/ ) and the Yucaipa Valley Hydrogeology study ( https://ca.water.usgs.gov/yucaipa/ ). Quality-assurance blank samples were processed periodically throughout the study and show that approximately 2.4 percent of the analytical results for major and minor ions, trace elements, and nutrients, and 1.5 percent of the results for VOCs fall below the acceptable study reporting limits and therefore are censored.

California↗

USGS2011

Analysis of methods to determine storage capacity of, and sedimentation in, Loch Lomond Reservoir, Santa Cruz County, California, 2009

In 2009, the U.S. Geological Survey, in cooperation with the City of Santa Cruz, conducted bathymetric and topographic surveys to determine the water storage capacity of, and the loss of capacity owing to sedimentation in, Loch Lomond Reservoir in Santa Cruz County, California. The topographic survey was done as a supplement to the bathymetric survey to obtain information about temporal changes in the upper reach of the reservoir where the water is shallow or the reservoir may be dry, as well as to obtain information about shoreline changes throughout the reservoir. Results of a combined bathymetric and topographic survey using a new, state-of-the-art method with advanced instrument technology indicate that the maximum storage capacity of the reservoir at the spillway altitude of 577.5 feet (National Geodetic Vertical Datum of 1929) was 8,646 ±85 acre-feet in March 2009, with a confidence level of 99 percent. This new method is a combination of bathymetric scanning using multibeam-sidescan sonar, and topographic surveying using laser scanning (LiDAR), which produced a 1.64-foot-resolution grid with altitudes to 0.3-foot resolution and an estimate of total water storage capacity at a 99-percent confidence level. Because the volume of sedimentation in a reservoir is considered equal to the decrease in water-storage capacity, sedimentation in Loch Lomond Reservoir was determined by estimating the change in storage capacity by comparing the reservoir bed surface defined in the March 2009 survey with a revision of the reservoir bed surface determined in a previous investigation in November 1998. This revised reservoir-bed surface was defined by combining altitude data from the 1998 survey with new data collected during the current (2009) investigation to fill gaps in the 1998 data. Limitations that determine the accuracy of estimates of changes in the volume of sedimentation from that estimated in each of the four previous investigations (1960, 1971, 1982, and 1998) are a result of the limitations of the survey equipment and data-processing methods used. Previously used and new methods were compared to determine the recent (1998-2009) change in storage capacity and the most accurate and cost-effective means to define the reservoir bed surface so that results can be easily replicated in future surveys. Results of this investigation indicate that the advanced method used in the 2009 survey accurately captures the features of the wetted reservoir surface as well as features along the shoreline that affect the storage capacity calculations. Because the bathymetric and topographic data are referenced to a datum, the results can be easily replicated or compared with future results. Comparison of the 2009 reservoir-bed surface with the surface defined in 1998 indicates that sedimentation is occurring throughout the reservoir. About 320 acre-feet of sedimentation has occurred since 1998, as determined by comparing the revised 1998 reservoir-bed surface, with an associated maximum reservoir storage capacity of 8,965 acre-feet, to the 2009 reservoir bed surface, with an associated maximum capacity of 8,646 acre-feet. This sedimentation is more than 3 percent of the total storage capacity that was calculated on the basis of the results of the 1998 bathymetric investigation.

California↗

USGS2007

Water-level and land-subsidence studies in the Mojave River and Morongo groundwater basins

Since 1992, the U.S. Geological Survey (USGS), in cooperation with the Mojave Water Agency (MWA), has constructed a series of regional water-table maps for intermittent years in a continuing effort to monitor groundwater conditions in the Mojave River and Morongo groundwater basins. The previously published data, which were used to construct these maps, can be accessed on the interactive map. The associated reports describing the groundwater conditions for the Mojave River groundwater basin for 1992 (Stamos and Predmore, 1995), the Morongo groundwater basin for 1994 (Trayler and Koczot, 1995), and for both groundwater basins for 1996 (Mendez and Christensen, 1997); for 1998 (Smith and Pimentel, 2000), for 2000 (Smith, 2002), for 2002 (Smith and others, 2004), for 2004 (Stamos and others, 2004), and for 2006 (Stamos and others, 2007) can be accessed using this web site. Spatially detailed maps of interferometric synthetic aperture radar (InSAR) methods were used to characterize land subsidence associated with groundwater-level declines during various intervals of time between 1992 and 1999 in the Mojave River and Morongo groundwater basins (Sneed and others, 2003). Concerns related to the potential for new or renewed land subsidence in the basins resulted in a cooperative study between the MWA and the USGS in 2006. InSAR data were developed to determine the location, extent, and magnitude of vertical land-surface changes in the Mojave River and Morongo groundwater basins for time intervals ranging from about 35 days to 14 months between 1999 and 2000 and between 2003 and 2004. (interactive Google map) The results from many future land-subsidence studies, which are scheduled about every 10 years, will be available on this website. Mapping of water-level contours, water-level change and numerous InSAR images were combined in an interactive map. This interactive map may be customized to your needs and viewed at a scale that is appropriate for the data.

California↗

USGS2006

Hydrology, description of computer models, and evaluation of selected water-management alternatives in the San Bernardino area, California

The San Bernardino area of southern California has complex water-management issues. As an aid to local water managers, this report provides an integrated analysis of the surface-water and ground-water systems, documents ground-water flow and constrained optimization models, and provides seven examples using the models to better understand and manage water resources of the area. As an aid to investigators and water managers in other areas, this report provides an expanded description of constrained optimization techniques and how to use them to better understand the local hydrogeology and to evaluate inter-related water-management problems. In this report, the hydrology of the San Bernardino area, defined as the Bunker Hill and Lytle Creek basins, is described and quantified for calendar years 1945-98. The major components of the surface-water system are identified, and a routing diagram of flow through these components is provided. Annual surface-water inflow and outflow for the area are tabulated using gaged measurements and estimated values derived from linear-regression equations. Average inflow for the 54-year period (1945-98) was 146,452 acre-feet per year; average outflow was 67,931 acre-feet per year. The probability of exceedance for annual surface-water inflow is calculated using a Log Pearson Type III analysis. Cumulative surface-water inflow and outflow and ground-water-level measurements indicate that the relation between the surface-water system and the ground-water system changed in about 1951, in about 1979, and again in about 1992. Higher ground-water levels prior to 1951 and between 1979 and 1992 induced ground-water discharge to Warm Creek. This discharge was quantified using streamflow measurements and can be estimated for other time periods using ground-water levels from a monitoring well (1S/4W-3Q1) and a logarithmic-regression equation. Annual wastewater discharge from the area is tabulated for the major sewage and power-plant facilities. More...

Open-File Report↗

USGS2006

Sources of High-Chloride Water to Wells, Eastern San Joaquin Ground-Water Subbasin, California

As a result of pumping and subsequent declines in water levels, chloride concentrations have increased in water from wells in the Eastern San Joaquin Ground-Water Subbasin, about 80 miles east of San Francisco (Montgomery Watson, Inc., 2000). Water from a number of public-supply, agricultural, and domestic wells in the western part of the subbasin adjacent to the San Joaquin Delta exceeds the U.S. Environmental Protection Agency Secondary Maximum Contaminant Level (SMCL) for chloride of 250 milligrams per liter (mg/L) (fig. 1) (link to animation showing chloride concentrations in water from wells, 1984 to 2004). Some of these wells have been removed from service. High-chloride water from delta surface water, delta sediments, saline aquifers that underlie freshwater aquifers, and irrigation return are possible sources of high-chloride water to wells (fig. 2). It is possible that different sources contribute high-chloride water to wells in different parts of the subbasin or even to different depths within the same well.

Open-File Report↗

USGS2000

Storage capacity and sedimentation of Loch Lomond Reservoir, Santa Cruz County, California, 1998

In 1998, a bathymetric survey was done to determine the storage capacity and the loss of capacity owing to sedimentation of Loch Lomond Reservoir in Santa Cruz County, California. Results of the survey indicate that the maximum capacity of the reservoir is 8,991 acre-feet in November 1998. The results of previous investigations indicate that storage capacity of the reservoir is less than 8,991 acre-feet. The storage capacity determined from those investigations probably were underestimated because of limitations of the methods and the equipment used. The volume of sedimentation in a reservoir is considered equal to the decrease in storage capacity. To determine sedimentation in Loch Lomond Reservoir, change in storage capacity was estimated for an upstream reach of the reservoir. The change in storage capacity was determined by comparing a 1998 thalweg profile (valley floor) of the reservoir with thalweg profiles from previous investigations; results of the comparison indicate that sedimentation is occurring in the upstream reach. Cross sections for 1998 and 1982 were compared to determine the magnitude of sedimentation in the upstream reach of the reservoir. Results of the comparison, which were determined from changes in the cross-sectional areas, indicate that the capacity of the reservoir decreased by 55 acre-feet.

California↗

USGS1998

Flood-inundation map and water surface profiles for floods of selected recurrence intervals, Cosumnes River and Deer Creek, Sacramento County, California

The damage caused by the January 1997 floods along the Cosumnes River and Deer Creek generated new interest in planning and managing land use in the study area. The 1997 floodflow peak, the highest on record and considered to be a 150-year flood, caused levee failures at 24 locations. In order to provide a technical basis for floodplain management practices, the U.S. Goelogical Survey, in cooperation with the Federal Emergency Management Agency, completed a flood-inundation map of the Cosumnes River and Deer Creek drainage from Dillard Road bridge to State Highway 99. Flood frequency was estimated from streamflow records for the Cosumnes River at Michigan Bar and Deer Creek near Sloughhouse. Cross sections along a study reach, where the two rivers generally flow parallel to one another, were used with a step-backwater model (WSPRO) to estimate the water-surface profile for floods of selected recurrence intervals. A flood-inundation map was developed to show flood boundaries for the 100-year flood. Water-surface profiles were developed for the 5-, 10-, 50-, 100-, and 500-year floods.

California↗

USGS1995

Land use and water use in the Antelope Valley, California

Urban land use and water use in the Antelope Valley, California, have increased significantly since development of the valley began in the late 1800's.. Ground water has been a major source of water in this area because of limited local surface-water resources. Ground-water pumpage is reported to have increased from about 29,000 acre-feet in 1919 to about 400,000 acre-feet in the 1950's. Completion of the California Aqueduct to this area in the early 1970's conveyed water from the Sacramento-San Joaquin Delta, about 400 miles to the north. Declines in groundwater levels and increased costs of electrical power in the 1970's resulted in a reduction in the quantity of ground water that was pumped annually for irrigation uses. Total annual reported ground-water pumpage decreased to a low of about 53,200 acre-feet in 1983 and increased to about 91,700 acre-feet in 1991 as a result of rapid urban development and the 1987-92 drought. This increased urban development, in combination with several years of drought, renewed concern about a possible return to extensive depletion of ground-water storage and increased land subsidence. Increased water demands are expected to continue as a result of increased urban development. Water-demand forecasts in 1980 for the Antelope Valley indicated that total annual water demand by 2020 was expected to be about 250,000 acre-feet, with agricultural demand being about 65 percent of this total. In 1990, total water demand was projected to be about 175,000 acre-feet by 2010; however, agricultural water demand was expected to account for only 37 percent of the total demand. New and existing land- and water-use data were collected and compiled during 1992-93 to identify present and historical land and water uses. In 1993, preliminary forecasts for total water demand by 2010 ranged from about 127,500 to 329,000 acre-feet. These wide-ranging estimates indicate that forecasts can change with time as factors that affect water demand change and different forecasting methods are used. The forecasts using the MWD_MAIN (Metropolitan Water District of Southern California Municipal and Industrial Needs) water-demand forecasting system yielded the largest estimates of water demand. These forecasts were based on projections of population growth and other socioeconomic variables. Initial forecasts using the MWD_MAIN forecasting system commonly are considered "interim" or preliminary. Available historical and future socioeconomic data required for the forecasting system are limited for this area. Decisions on local water-resources demand management may be made by members of the Antelope Valley Water Group and other interested parties based on this report, other studies, their best judgement, and cumulative knowledge of local conditions. Potential water-resource management actions in the Antelope Valley include (1) increasing artificial ground-water recharge when excess local runoff (or imported water supplies) are available; (2) implementing water-conservation best-management practices; and (3) optimizing ground-water pumpage throughout the basin.

Water-Resources Investigations Report↗