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Kenneth L. Wahl

Publications and source records attributed to Kenneth L. Wahl.

13 recordsLinked to original sources
USGS2003

Changes in streamflow and summary of major-ion chemistry and loads in the North Fork Red River basin upstream from Lake Altus, northwestern Texas and western Oklahoma, 1945-1999

Upstream from Lake Altus, the North Fork Red River drains an area of 2,515 square miles. The quantity and quality of surface water are major concerns at Lake Altus, and water-resource managers and consumers need historical information to make informed decisions about future development. The Lugert-Altus Irrigation District relies on withdrawals from the lake to sustain nearly 46,000 acres of agricultural land. Kendall's tau tests of precipitation data indicated no statistically significant trend over the entire 100 years of available record. However, a significant increase in precipitation occurred in the last 51 years. Four streamflow-gaging stations with more than 10 years of record were maintained in the basin. These stations recorded no significant trends in annual streamflow volume. Two stations, however, had significant increasing trends in the base-flow index, and three had significant decreasing trends in annual peak flows. Major-ion chemistry in the North Fork Red River is closely related to the chemical composition of the underlying bedrock. Two main lithologies are represented in the basin upstream from Lake Altus. In the upper reaches, young and poorly consolidated sediments include a range of sizes from coarse gravel to silt and clay. Nearsurface horizons commonly are cemented as calcium carbonate caliche. Finer-grained gypsiferous sandstones and shales dominate the lower reaches of the basin. A distinct increase in dissolved solids, specifically sodium, chloride, calcium, and sulfate, occurs as the river flows over rocks that contain substantial quantities of gypsum, anhydrite, and dolomite. These natural salts are the major dissolved constituents in the North Fork Red River.

Oklahoma, Texas↗
USGS1997

Changes in flow in the Beaver-North Canadian River basin upstream from Canton Lake, western Oklahoma

This report presents the results of an evaluation of hydrologic data for the Beaver-North Canadian River basin upstream from Canton Lake in western Oklahoma. It examines the climatic and hydrologic data for evidence of trends. The hydrologic data examined includes total annual flow, base flow, and annual peak discharges. This study was conducted to determine if there is evidence of trends present in hydrologic and climatic data. All available streamflow-gaging station data, with at least 10 or more years of record, were examined for trends. In addition, the data were divided into an 'early' period (ending in 1971), representing conditions before ground-water levels had declined appreciably, and a 'recent' period (1978-1994), reflecting the condition of declining ground-water levels, including the effects of storage reservoirs. Tests for trend, moving averages, and comparisons of median and average flows for an early period (ending in 1971) with those for the recent period (1978-1994) show that the total annual volume of flow and the magnitudes of instantaneous annual peak discharges measured at most gaging stations in the Beaver- North Canadian River basin have decreased in recent years. Precipitation records for the panhandle, however, show no corresponding changes. The changes in flow are most pronounced in the headwaters upstream from Woodward, but also are evident at Woodward and near Seiling, which represents the inflow to Canton Lake. The average annual discharge decreased between the early period and the recent period by the following amounts: near Guymon, 18,000 acre-feet; at Beaver, 68,000 acre-feet; at Woodward, 72,000 acre-feet; and near Seiling, 63,000 acre-feet. These decreases, expressed as a percentage of the average flows for the early period, were 91 percent near Guymon, 82 percent at Beaver, 49 percent at Woodward, and 37 percent near Seiling. The medians of the annual peak discharges decreased from the early period to the recent period by the following amounts: near Guymon, 98 percent; at Beaver, 86 percent; at Woodward, 80 percent; and near Seiling, 53 percent. The Guymon gage is not affected by reservoirs; the other three mainstem gaging stations are influenced by reservoirs, but the decreases in annual peak discharges are greater than can be explained by storage in those reservoirs. Base flows have undergone substantial change, but unlike the annual volumes the base flows show some increases and some decreases. Flow duration analyses show a shift in the distribution of annual flows. Less contribution is coming from large floods that formerly added substantially to the yearly average flows. Near Seiling, for example, the magnitudes of the large flows that occur less than about 20 percent of the time were greatly reduced in the recent period. A primary mechanism producing these decreased streamflows appears to be the depletion of ground water in the High Plains aquifer that underlies more than 90 percent of the basin. Changes in farming and conservation practices and in water use also may be having an effect.

Oklahoma↗
USGS1995

The stream-gaging program of the U.S. Geological Survey

The U.S. Geological Survey stream-gaging program provides streamflow data for a variety of purposes. The uses of streamflow data are described, and the growth of the stream-gaging program is related to legislation and the need to manage the Nation's water resources more effectively. A brief description is provided of the data-collection processes, computation of streamflow records, dissemination of data, and the nationwide evaluations of the stream-gaging program. Finally, the challenges for maintaining a viable stream-gaging program are described.

Circular↗
USGS1995

Channel degradation in southeastern Nebraska Rivers

Many stream channels in southeastern Nebraska were dredged and straightened during 1904-15. The resulting channels were both shorter and steeper than the original channels. Tests for time trends were conducted using the nonparametric Kendall tau test to see if the channels have responded to these changes. Tests were conducted on the stages associated with specific discharges and on measurement characteristics at gaging stations. Tests also were conducted on hydrologic forcing variables (annual mean precipitation, annual peak discharges, annual mean discharge, and annual mean base flows). The null hypothesis (that the data were free from trend) was rejected for stages associated with the mean of the annual discharges for 6 of 7 gaging stations in the study area, but was accepted for all 3 gages on the main stem of the Missouri River. The trends at the 6 streamflow gaging stations were for decreasing stages (degrading channels) for specific discharges. The rates of change ranged from about 0.2 to 0.5 m per decade. Mean stream bed elevations computed for individual discharge measurements at these streamflow gaging stations confirmed that the channels are degrading. However, neither the precipitation nor flow variables show evidence of trends. The tendency for the channels to degrade thus cannot be attributed to changes in runoff characteristics and are assumed to be a response to the channel modifications in the early 1900's. Indications are that the channels presently are continuing to degrade.

Conference Paper↗
USGS1994

Bias in regression estimates of manning's n

Selected equations for estimating roughness for gravel-bed streams were tested using a composite data set containing much of the data used to define the equations. All equations tested were found to significantly underestimate n for relatively low discharges. For floods about equal to the median annual peak discharge, Jarrett's equation overestimates n (median error = 10 percent) while the other equations tested showed no bias. Extrapolation of any of these equations to discharges greater than about 1.5 times the median annual peak discharge is presently unwarranted. The roughness of mountain streams is known to generally decrease as discharge and flow depth increases. The data, however, are presently not available to test the applicability of the equations to large flood discharges.

Conference Paper↗
USGS1993

Precipitation in the upper Mississippi River basin, January 1 through July 31, 1993

Excessive precipitation produced severe flooding in a nine-State area in the upper Mississippi River Basin during spring and summer 1993. Following a spring that was wetter than average, weather patterns that persisted from early June through July caused the upper Midwest to be deluged with an unusually large amount of rainfall. Monthly precipitation data were examined at 10 weather-station locations in the flood-affected region to illustrate precipitation patterns and amounts in the flood-affected area. In 1993, all 10 of the selected locations received greater than the normal rainfall for January through June 1961-90, 8 of the 10 locations received more than 200 percent of the normal rainfall for July 1961-90, and 3 received more than 400 percent of the normal rainfall for July. (The average rainfall for any given 30-year period is termed the 'normal' rainfall for the given period.) May through July 1993 was the wettest or nearly the wettest such period on record at many locations in the flooded area. Of the 10 locations, 6 received more rainfall in the first 7 months of 1993 than generally is received in a year.

upper Mississippi River basin↗
USGS1993

Potential problem with mean dimensionless hydrographs at ungaged sites

A flood hydrograph for an ungaged stream site can be estimated from a mean dimensionless hydrograph and estimates of instantaneous peak discharge (Q) and total storm runoff volume (V). However, the time base of the resulting flood hydrograph can be inversely related to the magnitude of the peak discharge if estimates of runoff volume were defined using ordinary least-squares regression relations of the form V=f(Q). Such an inverse relation is not hydrologically consistent. The problem can be solved in several ways. Redefining the relation between V and Q using an alternative model that preserves the variance in V generally will produce exponents for Q that are near 1. The resulting estimated flood-hydrograph volumes will nearly match the original volumes near the mean of the logarithms of V and Q, but will differ as volumes and peak discharges depart from the mean values. The difference will depend on how much the original exponent of Q differed from 1. Another solution is to simply hold T???, the multiplier needed to expand the time base of a mean dimensionless hydrograph into the time base of an estimated flood hydrograph, constant. That solution is a questionable approach if basins vary either in size, shape, or slope. A third solution is to define T??? as a function of time to peak, Tp. Flood volume then depends only on Q, Tp, and the dimensionless hydrograph, thereby removing the need to define a relation for estimating volume.

Conference Paper↗
USGS1993

Variation of froude number with discharge for large-gradient steams

Under chemical-control conditions, the Froude number (f) for a cross-section can be approximated as a function of the ratio R2/ 3/d 1/2 , where R is the hydraulic radius and d is the average depth. For cross sections where the ratio increases with increasing depth, F can also increase with depth Current-meter measurement data for 433 streamflow gaging stations in Colorado were reviewed, and 62 stations were identified at which F increases with depth of flow. Data for four streamflow gaging stations are presented. In some cases, F approaches 1 as the discharge approaches the magnitude of the median annual peak discharge. The data also indicate that few actual current meter measurement have been made at the large discharges where velocities can be supercritical.

Conference Paper↗
USGS1991

Is April to July runoff really decreasing in the Western United States?

Global warming has been the topic of a great deal of heated discussion and debate in recent years, both in the lay press and in scientific journals. The debate is about whether we are beginning to detect signs of a buildup of greenhouse gases on a global scale. A major part of the debate concerns the possible effects on climate and on the future availability of water resources. The ongoing drought in California has added impetus to the debate, serving notice of the serious consequences of any prolonged decrease in the availability of adequate water supplies. This paper has three primary objectives: (1) To evaluate the ramifications of using fractional runoff rather than total runoff to define trends in runoff; (2) to analyze additional streamflow data for the presence and extent of trends in annual and seasonal runoff volume for the conterminous Western United States; and (3) to examine the influence of the current California drought on indicators of trend.

Conference Paper↗
USGS1980

Floods of January and February 1980 in California

During January and February 1980, storms caused substantial rises in streamflow throughout much of California. In mid-January flooding occurred in the foothills of the Sierra Nevada and in the central coast area. In late January and mid-February, high floodflows in streams in coastal southern California caused much damage and several deaths. The Tijuana River in northern Baja California (Mexico) and southern San Diego County flooded many square miles of lowlands as its flow during two separate flooding episodes exceeded all records. Most reservoirs in San Diego County spilled, several for the first time since their completion. Lake Elsinore, in eastern Riverside County, caused much damage to lakeside property as it filled to an elevation not reached since 1916. The February flooding in southern California was caused by a series of storms separated by short intervals. Some peaks of record were observed, and streamflow throughout the area remained high for a relatively long period. In many streams, the volumes of sustained flow for periods of 7 and 15 consecutive days were the greatest that have occurred during the period of record.

California↗
USGS1977

Accuracy of channel measurements and the implications in estimating streamflow characteristics

Regional relations between flow characteristics and stream-channel size offer a promising alternative to available methods of estimating flow characteristics for ungauged sites, particularly in semiarid regions. The reliability of such relations and of flow estimates made from them is partly dependent on the user's ability to recognize a suitable reach and the reference levels in that reach. A test was made in northern Wyoming to determine how consistently trained individuals could measure channel size for three different reference levels. Seven participants independently visited 22 sites and measured channel dimensions in sections of their choosing. Assuming that the functional relation between a discharge characteristic ( Q ) and channel width ( W ) is log Q=f(1.5 log W ) and that the average log W from seven measurements is the best estimate of log W at a site, an average standard error for discharge of about 30 percent was attriluted to differences in width measurements alone.

Journal of Research of the U.S. Geological Survey↗