Publications

No abstract available.

Stream sediments adsorb certain solutes from streams, thereby significantly changing the solute composition; but little is known about the details and rates of these adsorptive processes. To investigate such processes, a 24-hr. injection of a solution containing chloride, strontium, potassium, sodium and lead was made at the head of a 640-m reach of Uvas Creek in west-central Santa Clara County, C

As part of a plant survivability and ground water study in Owens Valley, California, semipermanent installations are used to measure continuous range‐land evapotranspiration in the valley's phreatophyte community. A proposed mobile installation also has been designed. The semipermanent micrometeoro‐logical station collects continuous data for solution of the Bowen ratio/energy budget equation and

By a proper treatment of the known boundary conditions of a boundary value problem, a complex variable boundary element method (CVBEM) can be used to exactly satisfy the known nodal point boundary values. In this fashion, a numerical model can be developed which generates relative error information along the problem boundary that can be used to reduce the modelling error by either an integrated me

No abstract available.

The U.S. Geological Survey has begun a research project to improve understanding of the mobilization, transport, and fate of petroleum contaminants in the shallow subsurface and to use this understanding to develop predictive models of contaminant behavior. The project site is near Bemidji in northern Minnesota where an accidental spill of 10,500 barrels of crude oil occurred when a pipeline broke

Sedimentary rocks of Paleozoic age in the Hollandale embayment in southeastern Minnesota are as much as 2,000 feet thick and, with the underlying Hinckley sandstone of Proterozoic age, comprise the following five layered aquifers (beginning with the oldest): the Mount Simon-Hinckley, Ironton-Galesville, Prairie du Chien-Jordan, St. Peter and Upper Carbonate. Many of the Paleozoic formations show t

Buried-drift aquifers are stratified sand and (or) gravel aquifers in glacial deposits that cannot be seen or inferred at the land surface. During the Pleistocene Epoch, four continental glaciations advanced and retreated across Minnesota, blanketing the bedrock surface with drift as much as 700 feet thick (fig. 1). Most of the drift consists of till, an unsorted, un-stratified mixture of clay sil

No abstract available.

An urban wetland in the Minneapolis-St. Paul Metropolitan Area was found to retain sediment and nutrient loads in runoff routed through the wetland. Sediment and nutrient loads in runoff were measured during 1982 at the inlet and outlet of the 6.4-bectare urban wetland. Comparison of annual loads entering and leaving the wetland showed that retention of incoming loads in the wetland was 97 percent

Primary productivity was measured monthly at 6 sites within San Francisco Bay, USA, throughout 1980. The 6 sites were chosen to represent a range of estuarine environments with respect to salinity, phytoplankton community composition, turbidity, and water depth. Annual net production over the photic zone ranged from 95 to 150 g C m-2, and was highest in regions of lowest turbidity. Daily photic zo

Recent investigations suggest that dispersion in aquifers is scale dependent and a function of the heterogeneity of aquifer materials. Theoretical stochastic studies indicate that determining hydraulic-conductivity variability in three dimensions is important in analyzing the dispersion process. Even though field methods are available to approximate hydraulic conductivity in three dimensions, the