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North-central Santa Cruz County is underlain mainly by folded sedimentary rocks of Tertiary and Cretaceous age that have been highly fractured by movements in the San Andreas fault system. Ground water is stored in fractures within shale and mudstone formations and in intergranular pore spaces within fine- to very fine-grained...

A computer program for simulating one-dimensional, unsteady temperature and solute transport in a river has been developed and documented for general use. The solution approach to the convective-diffusion equation uses a moving reference frame (Lagrangian) which greatly simplifies the mathematics of the solution procedure and dramatically reduces errors caused by...

Standard regression models were used as a tool to evaluate the transferability of streamflow characteristics for the small-streams network in Missouri. Station records were divided into segments and tested for adequacy of record length and sample size for two physiographic regions. The standard error of estimate for each calibrated regression...

A dam and reservoir have been proposed for construction on Center Creek, Jasper County, in southwestern Missouri. Ground-water levels in the hills adjacent to the reservoir will rise when the impoundment is completed. One of the problems is that the proposed site of Prosperity Reservoir is a few miles upstream...

A computer model of the Potomac-Raritan-Magothy aquifer system was used to simulate the effects of supplementing ground water with water from the Delaware River. Replacement of ground water pumpage with surface water in a 150-square-mile area near Camden, N.J., was simulated. Artificial recharge of surface water was also simulated in...

Four modified nonradioactive-tracer methods and 20 predictive equations for determination of stream-reaeration coefficients in three small Wisconsin streams were compared with the radioactive-tracer method developed by Tsivoglou. Of the four modified-tracer techniques, the propane-area technique, which measures the total weight of propane gas passing stream-sampling stations, yielded the least mean absolute...

The U.S. Geological Survey conducted a 1-year study to calibrate and demonstrate the use of a steady-state water quality model for a 42-mile reach of the Arkansas River in Pueblo County, Colo. Based on the calibration, the model is capable of accurately predicting concentrations of carbonaceous biochemical oxygen demand, total...

Moderately low snowfall and an early and abrupt spring thaw resulted in removal of most of the snow cover from the National Petroleum Reserve in Alaska (NPRA) before the snow survey of April 30 through May 2, 1979. Logistical problems and lack of snow permitted sampling at only seven sites....

Intensive study in an area of 12-square miles near Marienthal, Kansas, has shown a decrease of 30 to 50 percent in saturated thickness of the Ogallala Formation since the development of irrigation. Projections from a digital model indicated the additional water-level declines that might occur from 1978 to 1989 if...

The Ogallala Formation in the intensive-study area, an area of 12 square miles in northeastern Wichita County, west-central Kansas, has had a substantial decrease in saturated thickness since the development of irrigation. The annual water-level decline during 1950-78 ranged from 1.08 to 2.22 feet per year.The hydrologic system was investigated...

Urban stormwater data from four Miami, Fla. catchments were collected and compiled by the U.S. Geological Survey and were used for testing the applicability of deterministic modeling for characterizing stormwater flows from small land-use areas. A description of model calibration and verification is presented for: (1) A 40.8 acre single-family...

Federal and State legislation require the trophic classification of lakes and ponds in the State of Maine as part of a lake management program. In 1974, the State of Maine Department of Environmental Protection (DEP) adopted a preliminary set of procedures for establishing an index of lake trophic status. Also...

The waste-assimilation capacity of a 42-mile reach of the Arkansas River in Pueblo County, Colo., was evaluated using a one-dimensional steady-state water-quality model. The model was calibrated and verified using hydraulic and water-quality data collected in 1976 and 1979. The water-quality con-stituents modeled were 5-day carbonaceous biochemical oxygen demand, total...

A hydrologic analysis of the proposed Badger-Beaver Creeks artificial-recharge project in Morgan County, Colo., was made with the aid of three digital computer models: A canal-distribution model, a ground-water flow model, and a stream-aquifer model. Statistical summaries of probable diversions from the South Platte River based on a 27-year period...

In general, yield of water from individual wells in unconsolidated surficial deposits is low (0-10 gallons per minute). Several small, unconsolidated deposits may yield moderate quantities (50-100 gallons per minute) but these have not been adequately tested.Yields from 160 wells in the crystalline bedrock range from 0.5 gallons per minute...

Procedures are defined for estimating the magnitude and frequency of future flood peaks and flood volumes and for estimating the expected hydrograph shape of rainfall-induced runoff of small streams in South Dakota. The procedures are applicable to flood flows that are not significantly affected by artificial storage or other manmade...

The Indiana State Board of Health is developing a State water-quality management plan that includes establishing Limits for wastewater effluents discharged into Indiana streams. A digital model calibrated to conditions in Little Laughery Creek tributary and Little Laughery Creek was used to predict alternatives for future waste loadings that would...

Part of the San Bernardino urbanized area in California overlies formerly swampy lands with a history of flowing wells. This area , upgradient from and adjacent to the San Jacinto fault, contains a zone in an alluvial ground-water basin that is under artesian pressure. Since 1945, withdrawals have exceeded recharge...

A nearly threefold increase in demand for water in the 154-square-mile San Antonio Creek valley in California during the period 1958-77 has increased the potential for overdraft on the ground-water basin. The hydrologic budget for this period showed a perennial yield of about 9,800 acre-feet per year and an annual...

The strataified-drift aquifer in Farmington, Conn., is capable of yielding large amounts of water to individual wells. About 14 square miles of Farmington is underlain by stratified-drift deposits which, in places, are more than 450 feet thick. The most productive deposits are found in the Farmington River valley, from Unionville...

During the period 1972-79, the bedload in the Clearwater River ranged from about 50,000 tons (45,000 metric tons) per year in 1972 and 1974 to about 1,000 tons (910 metric tons) per year in the drought years of 1973 and 1977. Suspended-sediment load at the same location ranged from about...

Muskegon County, Michigan, disposes of wastewater by spray irrigating farmland on its waste-disposal site. Buried drains in the highly permeable unconfined aquifer at the site control the level of the water table. Hydraulic conductivity of the aquifer and drain-leakance, the reciprocal of resistance to flow into the drains, was determined...

A digital-computer model of the hydrologic flow system, with emphasis on ground water, was developed for Spokane Valley, Washington and Idaho. The current rate of ground-water pumping in Spokane Valley has little effect on water levels in the Spokane aquifer, although short-term water-level declines occur locally. The model was used...

The observation-well network in the vicinity of the two well fields is described in detail. Data obtained from the network from October 1976 through September 1977, as well as rainfall and pumpage records, are presented and discussed. Below-normal rainfall caused the water table and potentiometric surface of the Floridan aquifer...

An unconditionally stable and practical transport model for use in upland streams and rivers has been developed and verified. Basing the model on the Lagrangian, rather than the Eulerian, reference frame greatly reduces the numerical problems associated with solving the advective terms of the convective-diffusion equation. The model contains almost...