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T. H. Thompson

Publications and source records attributed to T. H. Thompson.

9 recordsLinked to original sources
USGS1994

Overview of the National Water-Quality Assessment Program

The Nation's water resources are the basis for life and our economic vitality. These resources support a complex web of human activities and fishery and wildlife needs that depend upon clean water. Demands for good-quality water for drinking, recreation, farming, and industry are rising, and as a result, the American public is concerned about the condition and sustainability of our water resources. The American public is asking: Is it safe to swim in and drink water from our rivers or lakes? Can we eat the fish that come from them? Is our ground water polluted? Is water quality degrading with time, and if so, why? Has all the money we've spent to clean up our waters, done any good? The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program was designed to provide information that will help answer these questions. NAWQA is designed to assess historical, current, and future water-quality conditions in representative river basins and aquifers nationwide. One of the primary objectives of the program is to describe relations between natural factors, human activities, and water-quality conditions and to define those factors that most affect water quality in different parts of the Nation. The linkage of water quality to environmental processes is of fundamental importance to water-resource managers, planners, and policy makers. It provides a strong and unbiased basis for better decisionmaking by those responsible for making decisions that affect our water resources, including the United States Congress, Federal, State, and local agencies, environmental groups, and industry. Information from the NAWQA Program also will be useful for guiding research, monitoring, and regulatory activities in cost effective ways.

Open-File Report↗
USGS1988

Hydrology of the Citrus Park Quadrangle, Hillsborough County, Florida

Rapid increases in population and development in the Citrus Park quadrangle northwest of Tampa have increased the demand for water from the surficial and Upper Floridan aquifers, while at the same time decreasing the amount of wetlands and agricultural or forested lands that formerly provided recharge to these aquifers. Because the study area is underlain by soluble deposits, sinkholes and small closed depressions are common surface features. Some of the lakes in the area are remnants of ancient sinkholes. Four streams drain the area. Two of the streams have been channelized to reduce the risk of local flooding. Pumping from three municipal well fields within the study area and from three nearby well fields has lowered the potentiometric surface of the Upper Floridan aquifer. The pumping also lowers the water table levels by inducing recharge from the surficial aquifer to the Upper Floridan aquifer. Heavy pumpage may prompt sinkhole activity, or in areas near the coast , induce saltwater intrusion. Water quality of streams and groundwater is generally good except in the vicinity of landfills and where saltwater encroachment into the principal water bearing unit has occurred along the coast. (USGS)

Water-Resources Investigations Report↗
USGS1977

Use of infrared imagery in bank-storage studies

The use of thermal infrared imagery as a reconnaissance tool to identify bank seepage was investigated at Franklin D. Roosevelt Lake in northeastern Washington. The banks of the lake are generally composed of glacial lacustrine sediments deposited when the Cordilleran ice sheet dammed the Columbia River at least three times during the Pleistocene. The existence of a significant amount of bank storage was suspected. An airborne scanner having a spectral coverage of 8.5 to 11 micrometres and continuous filmstrip output was used in two test flights of March 27 and April 24, 1973. These flights were made during the reservoir drawdown when groundwater flow was from the banks to the reservoir and the ground water was warmer than the lake. The imagery shows temperatures in the lake ranging from 5° to 13° C. The lighter tones of the imagery show lake circulation patterns and extensive areas of bank seepage, spring discharge, stream inflow, and subsurface discharge which are all distinguishable from the darker tones of the colder lake surface. Bank seepage and ground-water discharge generally are evident where unconsolidated glacial sediment rather than bedrock is present.

Washington↗
USGS1968

Determination of discharge during pulsating flow

Pulsating flow in an open channel is a manifestation of unstable-flow conditions in which a series of translatory waves of perceptible magnitude develops and moves rapidly downstream. Pulsating flow is a matter of concern in the design and operation of steep-gradient channels. If it should occur at high stages in a channel designed for stable flow, the capacity of the channel may be inadequate at a discharge that is much smaller than that for which the channel was designed. If the overriding translatory wave carries an appreciable part of the total flow, conventional stream-gaging procedures cannot be used to determine the discharge; neither the conventional instrumentation nor conventional methodology is adequate. A method of determining the discharge during pulsating flow was tested in the Santa Anita Wash flood control channel in Arcadia, Calif., April 16, 1965. Observations of the dimensions and velocities of translatory waves were made during a period of controlled reservoir releases of about 100, 200, and 300 cfs (cubic feet per second). The method of computing discharge was based on (1) computation of the discharge in the overriding waves and (2) computation of the discharge in the shallow-depth, or overrun, part of the flow. Satisfactory results were obtained by this method. However, the procedure used-separating the flow into two components and then treating the shallow-depth component as though it were steady--has no theoretical basis. It is simply an expedient for use until laboratory investigation can provide a satisfactory analytical solution to the problem of computing discharge during pulsating flow. Sixteen months prior to the test in Santa Anita Wash, a robot camera had been designed .and programmed to obtain the data needed to compute discharge by the method described above. The photographic equipment had been installed in Haines Creek flood control channel in Los Angeles, Calif., but it had not been completely tested because of the infrequency of flow in that channel. Because the Santa Anita Wash tests afforded excellent data for analysis, further development of the photographic ,technique at Haines Creek was discontinued. Three methods for obtaining the data needed to compute discharge during pulsating flow are proposed. In two of the methods--the photographic method and the depth-recorder method--the dimensions and velocities of translatory waves are recorded, and discharge is then computed by the procedure developed in this report. The third method?the constant-rate-dye-dilution method--yields the discharge more directly. The discharge is computed from the dye-injection rate and the ratio of the concentration of dye in the injected solution to the concentration of dye in the water sampled at a site downstream. The three methods should be developed and tested in ,the Santa Anita Wash flood control channel under controlled conditions similar to those in the test of April 1965.

Water Supply Paper↗