Effect of depth of flow on discharge of bed material
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Geology topics
Publications and source records attributed to Bruce R. Colby.
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A procedure was presented in 1950 by H. A. Einstein for computing the total discharge of sediment particles of sizes that are in appreciable quantities in the stream bed. This procedure was modified by the U.S. Geological Survey and adapted to computing the total sediment discharge of a stream on the basis of samples of bed sediment, depth-integrated samples of suspended sediment, streamflow measurements, and water temperature. This paper gives simplified methods for computing total sediment discharge by the modified Einstein procedure. Each of four homographs appreciably simplifies a major step in the computations. Within the stated limitations, use of the homographs introduces much less error than is present in either the basic data or the theories on which the computations of total sediment discharge are based. The results are nearly as accurate mathematically as those that could be obtained from the longer and more complex arithmetic and algebraic computations of the Einstein procedure.
This report gives the results of an investigation by the U.S. Geological Survey and U.S. Bureau of Reclamation of sediment accumulation in stock reservoirs in the powder River drainage basin upstream from Arvada, Wyo. The study was made to determine the net rates of erosion in the upland areas and the effects of the reservoirs on the amount of sediment transported to the parent stream. The climate of the area ranges from cold and humid on the high mountains to warm and semiarid on the plains. The average annual precipitation ranges from less than 15 inches on the plains to more than 27 inches in the high mountains, which have a maximum altitude of 13,165 feet. The rocks in the Powder River drainage basin range in age from Precambrian to Recent. The 25 stock reservoirs that were used in the study have drainage areas of 0.09 to 3.53 square miles, are from 3 to 51 years old, and impound water from areas that have land slopes averaging from about 3 to 41 percent. The ratio of average reservoir capacity to drainage area ranges from about 2 to nearly 200 acre-feet per square mile. After adjustment for trap efficiency the average annual sediment yield to the 25 reservoirs ranged from 0.04 to 1.49 acre-feet per square mile and averaged 0.50 acre-foot per square mile of drainage area. The average sediment yield from 6 drainage areas mostly underlain by shale was 0.80 acre-foot per year, 2.3 times greater than yields from the areas underlain by sandstone or sandy shales. Correlations show that the sediment yield increased approximately as the 1.5 power of the channel density, the 0.4 power oif the shape factor, the 0.7 power of the average land slope, and the -0.25 power of the age of the reservoir. Empirical equations for sediment yield and trap efficiency for the area studied are given.
Devils Lake basin, a closed basin in northeastern North Dakota, covers about 3,900 square miles of land, the topography of which is morainal and of glacial origin. In this basin lies a chain of waterways, which begins with the Sweetwater group and extends successively through Mauvais Coulee, Devils Lake, East Bay Devils Lake, and East Devils Lake, to Stump Lake. In former years when lake levels were high, Mauvais Coulee drained the Sweetwater group and discharged considerable water into Devils Lake. Converging coulees also transported excess water to Stump Lake. For at least 70 years prior to 1941, Mauvais Coulee flowed only intermittently, and the levels of major lakes in this region gradually declined. Devils Lake, for example, covered an area of about 90,000 acres in 1867 but had shrunk to approximately 6,500 acres by 1941. Plans to restore the recreational appeal of Devils Lake propose the dilution and eventual displacement of the brackish lake water by fresh water that would be diverted from the Missouri River. Freshening of the lake water would permit restocking Devils Lake with fish. Devils and Stump Lake have irregular outlines and numerous windings and have been described as lying in the valley of a preglacial river, the main stem and tributaries of which are partly filled with drift. Prominent morainal hills along the south shore of Devils Lake contrast sharply with level farmland to the north. The mean annual temperature of Devils Lake basin ranges between 36 ? and 42 ? F. Summer temperatures above 100 ? F and winter temperatures below -30 ? Fare not uncommon. The annual precipitation for 77 years at the city of Devils Lake averaged 17.5 inches. Usually, from 75 to 80 percent of the precipitation in the basin falls during the growing season, April to September. From 1867 to 1941 the net fall of the water surface of Devils Lake was about 38 feet. By 1951 the surface had risen fully 14 feet from its lowest altitude, 1,400.9 feet. Since 1951, the level has fallen slowly. Hydrologic changes that may have caused Devils Lake to alter from a very large, moderately deep lake of fresh water to a small, shallow body of brackish water are discussed and evaluated on the basis of scanty information. During several years of average precipitation, temperature, and evaporation, Devils Lake and lakes upstream should receive nearly a quarter of an inch of runoff annually from the drainage area of about 3,000 square miles. Approximately 55 square miles of tributary area would be required to maintain each square mile of lake surface. However, runoff, expressed as percentage of the average, differs greatly from year to year. The amount of runoff retained in upstream lakes also Varies greatly. For these two reasons, annual inflow to Devils Lake is extremely variable. Because many waterways in this basin have no surface outlets at normal stages, runoff collects in depressions, is concentrated by evaporation, and forms saline or alkaline lakes. The chemical and physical properties of the lake waters vary chiefly with changes in lake stage and volume of inflow. Scattered records from 1899 to 1923 and more comprehensive data from 1948 to 1952 show a range of salt concentration from 6,130 to 25,000 parts per million (ppm) in the water of Devils Lake. Although concentration has varied, the chemical composition of the dissolved solids has not changed appreciably. Lake waters are more concentrated in the lower part of the basin, downstream from Devils Lake. For periods of record the salt concentration ranged from 14,932 to 62,000 ppm in East Devils Lake and from 19,000 to 106,000 ppm in east Stump Lake. Current and past tonnages of dissolved solids in Devils Lake, East Bay Devils Lake, East Devils Lake, and east and west Stump Lakes were computed from concentrations and from altitude-capacity curves for each lake. Neither the average rate of diversion of water to restore Devils Lake to a higher level nor the quality of the divert
This report contains results of observations that were made from the time when a natural constriction was formed in the Niobrara River near Valentine, Nebr., to the time when it was widened by high flows. After the constriction was widened, insufficient turbulence was developed to suspend most of the sediment. The report gives information on the amount and characteristics of the sediment that moves as unmeasured load at normal sections of the stream near the constriction and at the measuring sections at the Sparks gaging station. Lateral distributions of depth, velocity, and concentration are shown for the sections where sediment discharge was measured. In addition, vertical distributions of concentration, velocity, and percentage of particles coarser than 0.25 mm are shown for the contracted section. The vertical distributions seem to indicate that the total sediment load of the stream was usually in suspension at the contracted section. Exclusive of the period during the winter when upstream reservoirs. were not flushed, the measured discharge of suspended sediment at the normal sections near the contraction averaged 47 percent and at the Sparks gaging station 41 percent of the measured sediment discharge at the contracted section. Particle sizes of suspended sediment and bed material are tabulated, and some size distributions are plotted. In conformity with bedload theory, the computed particle sizes of the unmeasured load were slightly smaller than the average particle sizes in the samples of bed material.
This report gives the results of an investigation by the U. S. Geological Survey of the sediments and dissolved minerals that are transported by the Moreau River. The Moreau River drainage basin is a narrow basin in northwestern South Dakota that covers about 5, 360 square miles of rolling, grassy plains, which are broken by buttes and by some small areas of badlands. It is underlain by shales, sandstones, siltstones, and limestones that are primarily of Cretaceous age. Precipitation averages about 16 inches per year. Average annual runoff is about 0. 7 inch but varies widely from year to year.
Within the Missouri River Basin the precipitation and temperature vary greatly with both time and geographical location. Differences in weather and climate combine with differences in topography and geology to produce large differences in runoff from time to time and from place to place in the basin. The average annual runoff ranges from a fraction of an inch for some drainage areas to more than 40 inches for a few small ungaged areas at high elevations. For some drainage areas the maximum annual discharge is 10 to 20 times the minimum. The amounts and distribution of runoff and discharge throughout a drainage basin are essential parts of any study of the water resources of that basin. Discharge records at gaging stations are only spot samples of surface-water resources and require interpretation in order to furnish a general knowledge of the amounts and distribution of runoff and discharge. Such a knowledge is necessary to an adequate understanding of the water resources of the drainage basin. This report contains maps that show for the Missouri River Basin. Representative average rates of discharge, the distribution of the average discharge by months for several gaging stations. representative annual runoff, and minimum annual runoff. These maps are supplemented by explanations and comments and by charts that show the development of irrigation by drainage areas and by States.