USGS ScienceSearch

Geology topics

Tate Dalrymple

Publications and source records attributed to Tate Dalrymple.

6 recordsLinked to original sources

General field and office procedures for indirect discharge measurements

The discharge of streams is usually measured by the current-meter method. During flood periods, however, it is frequently impossible or impractical to measure the discharges by this method when they occur. Consequently, many peak discharges must be determined after the passage of the flood by indirect methods, such as slope-area, contracted-opening, flow-over-dam, and flow-through-culvert, rather than by direct current-meter measurement. Indirect methods of determining peak discharge are based on hydraulic equations which relate the discharge to the water-surface profile and the geometry of the channel. A field survey is made after the flood to determine the location and elevation of high-water marks and the characteristics of the channel. Detailed descriptions of the general procedures used in collecting the field data and in computing the discharge are given in this report. Each of the methods requires special procedures described in subsequent chapters.

Techniques of Water-Resources Investigations

Flood-frequency analyses, Manual of Hydrology: Part 3

This report describes the method used by the U.S. Geological Survey to determine the magnitude and frequency of momentary peak discharges at any place on a stream, whether a gaging-station record is available or not. The method is applicable to a region of any size, as a river basin or a State, so long as the region is hydrologically homogeneous. The analysis provides two curves. The first expresses the flood discharge-time relation, showing variation of peak discharge, expressed as a ratio to the mean annual flood, with recurrence interval. The second relates the mean annual flood to the size of drainage area alone, or to the size area and other significant basin characteristics. A frequency curve may be defined for any place in the region by use of these two curves. The procedure is: (a) measure the drainage area and other appropriate basin characteristics from maps; (b) from the second curve, select the mean annual flood corresponding to the proper drainage area factors; (c) from the first curve, select ratios of peak discharge to mean annual flood for selected recurrence intervals, as 2, 10, 25, and 50 years; and (d) multiply these ratios by the mean annual flood and plot the resulting discharges of known frequency to define the frequency curve. Two reports not previously given general circulation are included as sections of this report. These are 'Plotting Positions in Frequency Analysis' by W. B. Langbein, and 'Characteristics of Frequency Curves Based on a Theoretical 1,000-Year Record' by M. A. Benson.

Water Supply Paper

Texas floods of 1938 and 1939

In January, June, and July 1938, and June 1939 parts of Texas experienced floods that exceeded previously recorded stages at many places and that were unusually high over reaches of several hundred miles on the streams of the State. This report presents records of precipitation at several hundred places; 10 isohyetal maps; records of peak stages and discharges and of daily mean discharges during the flood period at more than 30 river-measurement stations; hydrographs of discharge at 19 stations; records of suspended matter transported in stream channels by the flood; results of studies of rainfall and runoff; records of past floods in the Red, Sabine, and Colorado River Basins; and other data pertinent to the floods in Texas.

Water Supply Paper

Major Texas floods of 1935

In localities where highly mineralized water is present in beds above and below the beds that yield the supplies of fresh water it is necessary to be able to locate leaks in wells in order to know whether the wells are being contaminated through holes in the casings or whether the fresh water supply is failing. Four general methods of detecting salt-water leaks have been used. In the pumping method, samples taken at measured time intervals while the well is being pumped show by their progressive change in salinity if salt water is being drawn in. In the velocity method, which is suitable for use only in artesian wells, a current meter lowered into the well indicates the location of possible salt water leaks by determining the levels at which there are changes in the rate of upward movement of the water. In the sampler method a container lowered into the well brings up a sample from any depth desired for analysis of its chloride content. The electric conductivity method, for which special apparatus was designed, has been used successfully in the Winter Garden area and Kleberg County, Tex., and in Sarasota County, Fla. The procedure in this method was to lower a pair of insulated electrodes into the well and measure the resistance of the water between them with the Wheatstone bridge or, in waters low in chloride, to apply a direct current of low voltage and measure the current flowing between .the electrodes by means of a milliammeter. The installments showed a marked increase in the conductivity of the water as the electrodes passed from fresh to salt water in the well, leaving no doubt as to the location of the leaks.

Water Supply Paper

Floods in the Canadian and Pecos River basins of New Mexico, May and June 1937

In May and June floods occurred in the Canadian and Pecos River Basins of New Mexico that were unusually high and in many places were record breaking. The floods were caused by heavy rains that occurred over the eastern part of the State from May 23 to June 4 in a series of intense and intermittent storms. During these storms of the cloudburst type as much as 12 inches of rain fell in the 13-day period, and a fall of 7 inches in 2 hours and 40 minutes was reported from the vicinity of Clayton. Heavy rains also fell in the mountainous region west of Roswell, amounting to as much as l0 inches at some places. Much of the region that had excessive rainfall is relatively flat and has no well-defined drainage system. From these areas there was very little run-off and practically no water was contributed to the major streams. Hail fell at many places in eastern New Mexico, causing damage to crops, livestock, and other property. Hail fell somewhere in the Canadian and Pecos River Basins almost every day during the storm period, but the duration of the fall was generally short. The largest hailstones were reported from Clayton, where one stone measured 8 inches in circumference and weighed 9 ounces; at Centerville, where reports state that some stones were 9 to 10 inches in circumference; and near Roswell, where it was reported that six stones would fill a gallon bucket. The Canadian River flood reached a peak at Logan of 110,000 second-feet, which has been exceeded in this century only by the floods of 1904, 1909, and 1914. The total run-off at Logan for the flood period has been computed as 653,800 acre-feet. At Santa Rosa the Pecos River reached a maximum discharge of 88,200 second-feet, which is greater than any previously recorded. This flood was partly stored in the Alamogordo Reservoir; the peak below the reservoir was only 25,200 second-feet. The Pecos River flood at Roswell reached a maximum discharge of more than 80,000 second-feet. This water came mostly from tributaries that have .their sources in the mountainous area west of Roswell. The Cienaga del Macho, ordinarily a small dry creek, discharged about 49,800 second-feet at its peak. The Rio Hondo experienced several flood peaks, the largest at Roswell probably being near 20,000 second-feet. Berrendo Creek, which enters the Rio Hondo near Roswell, had a computed peak discharge of 37,700 second-feet. Roswell was subjected to several floods that inundated large areas of the town. Considerable damage was done by the water, which covered nearly all the area occupied by the town. Lake McMillan, an artificial reservoir on the Pecos River about 12 miles above Carlsbad, was put to a severe strain by the large quantity of water passing through it, but no serious damage resulted. The capacity of the lake at spillway level is about 39,000 acre-feet, but at the peak of the flood the lake held about 86,000 acre-feet. The total quantity of water passing through the lake during the flood period was more than 440,000 acre-feet. This report presents data pertinent to the floods of May and June 1937, including results of peak discharge determinations made at about 14 miscellaneous places, records of peak stages and discharges and of mean daily discharges during the flood period at 23 regular river-measurement stations, records of rainfall at about 190 places, an isohyetal map showing rainfall over the entire State and two isohyetal maps showing rainfall over the Canadian and Pecos River Basins, and a discussion of the weather conditions during the flood period, including an upper-air wind and pressure chart of the United States for May 28, 1937. In addition to the information listed above the report includes a summary of records of past floods at all places in New Mexico at which authentic records were available.

New Mexico