Geology topics

K.L. Wahl

Publications and source records attributed to K.L. Wahl.

4 recordsLinked to original sources

USGS2001

Changes in flow in the upper North Canadian river basin of western Oklahoma, pre-development to 2000

Water levels have declined in the southern part of the High Plains aquifer of the central USA since the mid-1960s in response to extensive irrigation development. The North Canadian River originates in western Oklahoma, and most of the basin is underlain by the High Plains aquifer. Average river flow in the headwaters near Guymon, Oklahoma, has decreased from about 0.9 m3/s before 1970 to near zero at present. Canton Lake, on the North Canadian River near Seiling, about 250 km downstream from Guymon, is a source of water supply for Oklahoma City. Precipitation data and streamflow data for gages upstream from Canton Lake were divided into an "early" period ending in 1971 and a "recent" period that begins in 1978. The early period represents conditions before ground-water levels had declined appreciably in the High Plains aquifer, and the recent period reflects the current condition, including the effects of storage reservoirs. Tests for trend and comparisons of flows between the early and recent periods show that the total annual volume of flow and the magnitudes of instantaneous annual peak discharges measured at most locations in the North Canadian River basin have decreased. Precipitation records for the area, however, show no corresponding changes. The decreases in average annual flow, expressed as a percentage of the average flows for the early period, ranged from 91 percent near Guymon to 37 percent near Canton Lake. A major contributing factor in the decreased flows appears to be the large declines in water levels in the High Plains aquifer.

Conference Paper↗

USGS1988

Cost-effectiveness of the streamflow-gaging program in Wyoming

This report documents the results of a cost-effectiveness study of the streamflow-gaging program in Wyoming. Regression analysis or hydrologic flow-routing techniques were considered for 24 combinations of stations from a 139-station network operated in 1984 to investigate suitability of techniques for simulating streamflow records. Only one station was determined to have sufficient accuracy in the regression analysis to consider discontinuance of the gage. The evaluation of the gaging-station network, which included the use of associated uncertainty in streamflow records, is limited to the nonwinter operation of the 47 stations operated by the Riverton Field Office of the U.S. Geological Survey. The current (1987) travel routes and measurement frequencies require a budget of $264,000 and result in an average standard error in streamflow records of 13.2%. Changes in routes and station visits using the same budget, could optimally reduce the standard error by 1.6%. Budgets evaluated ranged from $235,000 to $400,000. A $235,000 budget increased the optimal average standard error/station from 11.6 to 15.5%, and a $400,000 budget could reduce it to 6.6%. For all budgets considered, lost record accounts for about 40% of the average standard error. (USGS)

Water-Resources Investigations Report↗

USGS1984

Cost-effectiveness of the stream-gaging program in Nebraska

This report documents the results of a study of the cost-effectiveness of the streamflow information program in Nebraska. Presently, 145 continuous surface-water stations are operated in Nebraska on a budget of $908,500. Data uses and funding sources are identified for each of the 145 stations. Data from most stations have multiple uses. All stations have sufficient justification for continuation, but two stations primarily are used in short-term research studies; their continued operation needs to be evaluated when the research studies end. The present measurement frequency produces an average standard error for instantaneous discharges of about 12 percent, including periods when stage data are missing. Altering the travel routes and the measurement frequency will allow a reduction in standard error of about 1 percent with the present budget. Standard error could be reduced to about 8 percent if lost record could be eliminated. A minimum budget of $822,000 is required to operate the present network, but operations at that funding level would result in an increase in standard error to about 16 percent. The maximum budget analyzed was $1,363,000, which would result in an average standard error of 6 percent. (USGS)

Water-Resources Investigations Report↗

USGS1984

A pragmatic approach to evaluating a multipurpose stream-gaging network

A method for evaluating the relative worth of individual streamflow gaging stations in a multipupose network is presented. Each individual gaging station in the network is evaluated on the basis of selected rating factors. The factors relate to the need for information at the gaging stations, accuracy of data, economic aspects of operation, and usefulness of data as a basis for estimates at ungaged sites. The total score for the various factors provides a convenient basis for comparing relative importance of individual gaging stations. The rating-factor method is both flexible and definitive, but the point values that are assigned for each rating factor are somewhat subjective. A table of the point values and guidelines for assigning those values is presented. (USGS)

Water-Resources Investigations Report↗