Publications

Groundwater is the major source of water in Linn County and the surrounding area. Approximately 90 percent of the groundwater production is from Silurian, Devonian, and Quaternary aquifers. The Silurian and Devonian aquifers consist of limestone and dolomite with minor shale beds, which have a regional dip to the southwest of approximately 20 feet per mile. The Silurian aquifer in east-central Iow

A commercial low-level radioactive-waste disposal site has been operating near Beatty, Nevada, about 150 km northwest of Las Vegas, since 1962. The 32-ha site is situated in a desolate region of the Amargosa River Valley, sometimes referred to as the Amargosa Desert. Average annual precipitation is only about 114 mm. The site is underlain by 175 m of unconsolidated, generally coarse-grained, alluv

No abstract available.

No abstract available.

This report contains site descriptions and base-flow data collected at 362 partial-record sites in South Carolina. These data include site name, site description, latitude, longitude, drainage area, instantaneous streamflow, and date of the streamflow measurement. The base-flow data can be used as an aid to estimate low flow characteristics at ungaged locations on streams in South Carolina. Partia

Equations for estimating the 7-day, 2-year and 7-day, 10-year low flows at sites on ungaged streams are presented. Regression analysis was used to develop equations relating basin characteristics and low-flow characteristics at 82 gaging stations. Significant basin characteristics in the equations are contributing drainage area and flow-duration ratio, which is the 20-percent flow duration divided

Sedimentation resulting from storms may have been one of the reasons for the elimination of submersed aquatic vegetation from the tidal Potomac River in the late 1930's. Laboratory studies were conducted to investigate the effects of different depths of overlying sediment and composition of sediment on the survival of Vallisneria americana Michx (wildcelery) grown from tubers. Survival of plants g

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminate

This investigation assesses geographic variations in atmospheric deposition in Washington, Oregon, and California using snow cores from the Cascade-Sierra Nevada Mountains, collected from late February to mid-March 1983. A statistical analysis of the analytical and sampling precision was made. The snowpack in the higher Cascades and Sierra Nevada is not strongly influenced by anthropogenic activit

The U.S. Geological Survey is modeling hydraulic flow and thermal-energy transport at a two-well injection/ withdrawal system in St. Paul, Minnesota. The design of the finite-difference model grid for the doublet-well system is complicated because the aquifer is anisotropic and the principal axes of transmissivity are not aligned with the axis between the two wells. An analytical solution for flow

The 5-22 mu m size accounted for 40-50% of annual production in each embayment, but production by phytoplanton >22 mu m ranged from 26% in the S reach to 54% of total phytoplankton production in the landward embayment of the N reach. A productivity index is derived that predicts daily productivity for each size class as a function of ambient irradiance and integrated chlorophyll a in the photic zo

Historic fluctuations and late Quaternary deposits of Tulare Lake, in the southern San Joaquin Valley, indicate that maximum lake size has depended chiefly on the height of a frequently overtopped spillway. This dependence gives Tulare Lake a double record of paleoclimate. Climate in the Tulare Lake region has influenced the degree to which the lake fills its basin during dry seasons and dry years