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Geology topics

D.A. Olin

Publications and source records attributed to D.A. Olin.

6 recordsLinked to original sources
USGS1988

Estimating flood hydrographs and volumes for Alabama streams

The hydraulic design of highway drainage structures involves an evaluation of the effect of the proposed highway structures on lives, property, and stream stability. Flood hydrographs and associated flood volumes are useful tools in evaluating these effects. For design purposes, the Alabama Highway Department needs information on flood hydrographs and volumes associated with flood peaks of specific recurrence intervals (design floods) at proposed or existing bridge crossings. This report will provide the engineer with a method to estimate flood hydrographs, volumes, and lagtimes for rural and urban streams in Alabama with drainage areas less than 500 sq mi. Existing computer programs and methods to estimate flood hydrographs and volumes for ungaged streams have been developed in Georgia. These computer programs and methods were applied to streams in Alabama. The report gives detailed instructions on how to estimate flood hydrographs for ungaged rural or urban streams in Alabama with drainage areas less than 500 sq mi, without significant in-channel storage or regulations. (USGS)

Water-Resources Investigations Report↗
USGS1986

Flood-depth frequency relations for streams in Alabama

Equations were defined for estimating the depth of water for floods having recurrence intervals of 2, 5, 10, 25, 50, 100, and 200 years on rural and urban streams in Alabama. Multiple regression analyses were made using the ' maximum RSQUARE improvement ' procedures. The dependent variable was the flood depth and the independent variables were 10 basin and climatic characteristics. For rural streams, drainage area size (0.44 to 1,344 sq mi) was the only statistically significant independent variable tested to estimate flood depths in six different hydrologic areas. Other variables affecting flood depth relations are reflected in the equation constant and coefficient for each hydrologic area. These account for differences in geologic and topographic characteristics. For urban streams, drainage area size (0.16 to 83.5 sq mi) and percent impervious area (8.3% to 42.9%) of the basin were the most significant independent variables tested to estimate flood depths. For most streams where the drainage area is > 1,344 sq mi, the drainage basin extends into more than one hydrologic area and the equations presented would not apply. Flood profile data and gaging station records are available from the U.S. Geological Survey for use in estimating flood depths for these large streams. Flood routing and historic flood profiles are also available for many of the large streams which have flood regulation. (Author 's abstract)

Water-Resources Investigations Report↗
USGS1985

Magnitude and frequency of floods in Alabama

Methods are presented to estimate flood magnitude for selected recurrence intervals for urban and rural streams with drainage areas from 1 to 22,000 square miles. Seven hydrologic areas were delineated and regression equations were developed for six areas. Hydrologic data could not be regionalized for the seventh area. Drainage area was the only independent variable used in the equations for five hydrologic areas. Drainage area and a storage factor were used in the equations for the other area. One hydrologic area, located in the central part of the State, has flood runoffs two to four times greater than the other areas. It is recommended that the rural equations be used for estimates of flood magnitudes for both urban and rural streams in the hydrologic area. Rivers with drainage areas greater than 1,500 square miles could not be regionalized. Estimating methods for these rivers are shown graphically. Maximum flood magnitudes versus drainage area also are presented. (USGS)

Water-Resources Investigations Report↗