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Technique for estimating magnitude and frequency of floods in Maryland

Open-File Report 80-1016
Prepared in cooperation with the Maryland Department of Transportation State Highway Administration and the U.S. Department of Transportation Federal Highway Administration
By:
https://doi.org/10.3133/ofr801016

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Abstract

A method is presented for estimating flood magnitudes for natural drainage basins without urban development or regulated flow. The method was developed by multiple-regression techniques and applies to floods with recurrence intervals from 2 to 100 years.

The State is divided into three regions, and sets of equations for calculating peak discharges based on physical basin characteristics are provided for each region. In the northern region, flood-peak discharges are related to drainage area, forest cover, and 2-year 24-hour rainfall. In the southern region, flood peaks are related to drainage area alone. In the eastern region, peaks are related to drainage area, slope, storage, forest cover, and two composite soil categories. Standard errors of estimate for the regression equations in the northern region range from 38 to 49 percent. For the southern region, the standard errors of estimate vary from 52 to 86 percent, and for the eastern region they vary from 37 to 40 percent.

Maximum observed flood peaks, basin characteristics, and flood-frequency characteristics are tabulated for 234 gaged sites in Maryland and nearby in surrounding states. At 39 of these sites, a rainfall-runoff model was used to obtain synthetic flood-frequency data. These data were combined with observed flood-frequency data to determine the final flood-frequency distributions.

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Publication type Report
Publication Subtype USGS Numbered Series
Title Technique for estimating magnitude and frequency of floods in Maryland
Series title Open-File Report
Series number 80-1016
DOI 10.3133/ofr801016
Year Published 1980
Language English
Publisher U.S. Geological Survey
Description Report: v, 79 p.; 9 Plates: 41.67 x 48.80 inches or smaller
Country United States
State Maryland
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