USGS Science⌕ Search

Geology topics

M. A. Benson

Publications and source records attributed to M. A. Benson.

13 recordsLinked to original sources
USGS2007

Nationwide study of the streamflow data program

During 1970 the Geological Survey conducted a study to evaluate the surface-water data collection program. Objectives were formulated, specific goals were set, a massive analysis of available data was made to determine the extent to which the present system enables the goals to be met, alternatives were considered for meeting the remaining goals, and finally, specific elements were identified for inclusion in the future program. The results of the evaluation will be used in planning the future streamflow data program. Less productive elements in the present program can be weeded out, and the effort devoted to more critically needed water data. The study provides the groundwork for redirection of efforts towards a more efficient system for satisfying present and future needs.

Journal of the American Water Resources Associatio↗
USGS2001

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↗
USGS1968

Measurement of peak discharge by the slope-area method

This chapter describes application of the Manning equation to measure peak discharge in open channels. Field and office procedures limited to this method are described. Selection of reaches and cross sections is detailed, discharge equations are given, and a complete facsimile example of computation of a slope-area measurement is also given.

Techniques of Water-Resources Investigations↗
USGS1966

A definition of dominant discharge

The concept of dominant (stream) discharge in geomorphology has not been firmly defined. By defining it, on rational grounds, as that discharge at which, over a long period of time, most sediment has been transported, a definite value can be computed for a stream for which there are available duration-curve values of daily discharge and a sediment-rating curve. This has been done for 5 eastern and 4 western rivers. The dominant discharge , when expressed in terms of percentage duration, is remarkably consistent, and is found to be a lower discharge than has generally been considered as dominant .

International Association of Scientific Hydrology ↗
USGS1963

Factors influencing the occurrence of floods in a humid region of diverse terrain

This report describes relations between flood peaks and hydrologic factors in a humid region with limited climatic variation but a diversity of terrain. Statistical multiple-regression techniques have been applied to hydrologic data on New England. Many topographic and climatic factors have been evaluated. and their relations to flood peaks have been examined. Many of the factors that influence flood peaks are interrelated, and part of the investigation consisted of determining the most efficient factor in each of several groups of highly interrelated variables. Drainage area size was found to be the most important factor. Main-channel slope was found to be next in importance, and a simple yet efficient indicator of main-channel slope was developed. The surface area of lakes and ponds was found to be a factor significantly influencing peak discharges. Of several indices tested the intensity of rainfall for a given duration and frequency was found to be most highly related to the magnitude of peaks. The increase in peaks caused by snowmelt and frozen ground was found to be related to an index of winter temperature-the average number of degrees below freezing in January. After the above-mentioned topographic and climatic characteristics had been taken into account, there remained deviations in peak discharges that showed an evident relation to orographic patterns. An orographic factor was mapped as defined by the peak discharges of record. Multiple-regression equations were developed that related, with acceptable accuracy, peak discharges of 1.2-to 300-year recurrence intervals to 6 hydrologic variables; 3 of the variables were topographic, 2 climatic, and 1 orographic. The remaining unexplained variations in flood-peak occurrence are believed attributable to the chance variation in storms.

Water Supply Paper↗
USGS1962

Evolution of methods for evaluating the occurrence of floods

A brief summary is given of the history of methods of expressing flood potentialities, proceeding from simple flood formulas to statistical methods of flood-frequency analysis on a regional basis. Current techniques are described and evaluated. Long-term flood records in the United States show no justification for the adoption of a single type of theoretical distribution of floods. The significance and predictive values of flood-frequency relations are considered. Because of the length of flood records available and the interdependence of flood events within a region, the probable long-term average magnitudes of floods of a given recurrence interval are uncertain. However, if the magnitudes defined by the records available are accepted, the relative effects of drainage-basin characteristics and climatic variables can be determined with a reasonable degree of assurance.

Water Supply Paper↗
USGS1960

Areal flood-frequency analysis in a humid region

This study was made to define the relation between floods in a humid region and the causative factors that account for their variability. The study covered the basic relationships between peak discharges and hydrologic factors as well as the practical working methods for generalizing the results on a regional basis. Statistical multiple-correlation techniques were applied to hydrologic data in New England. A field and library investigation of historical flood data extended the period of flood knowledge to as much as 300 years. The relation of many topographic and climatic factors to flood peaks was tested. Flood peaks with recurrence intervals at 9 levels, from 1.2 to 300 years, were related to 6 independent variables, 3 of which are topographic, 2 climatic, and 1 orographic.

International Association of Scientific Hydrology ↗
USGS1960

Grid method of determining mean flow-distance in a drainage basin

The basin characteristics Σ al or L ca are useful in hydrologic studies, but existing methods of determining them are either tedious or somewhat inaccurate. The grid method presented herein lessens the amount of tedious labor and provides an accurate measure of either Σ al or L ca . An adaptation of the method could be used to compute the lag time for the basin.

International Association of Scientific Hydrology ↗