Techniques For Estimating Flood Peak Discharges From Urban Basins In Missouri

Author : Rodney E. Southard
Publisher :
ISBN 13 :
Total Pages : 60 pages
Book Rating : 4.:/5 (141 download)

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Download or read book A New Basin Characteristic for Use in Estimating Impervious Area and Flood Discharges in Urban Missouri Basins written by Rodney E. Southard and published by . This book was released on 1986 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A previous regression analysis of flood peaks on urban basins in St. Louis County, Missouri, indicated that the percentage of impervious area and drainage area were the only basin characteristics of statistical significance in estimating the 2-, 5-, 10-, 25-, 50-, and 100-year peak-flow discharges at ungaged urban basins. In this statewide regression analysis of urban basins, a new basin characteristic called the percentage of developed area was computed and used in a simple regression analysis. The regression analysis included percentage of developed area as the independent variable and impervious area as the dependent variable, resulting in a simplified procedure for computing impervious area. Finally, the percentage of developed area was evaluated using flood frequency estimates at 23 U.S. Geological Survey streamflow-gaging stations and verified to be valid for use in estimating these flood discharges. In a nationwide study by Sauer and others (1983) an urban basin characteristic called the basin development factor was determined to be valid for inclusion in urban regression equations for estimating floodflows. The basin development factor was statistically compared through multiple-regression analysis to the percentage of developed area for Missouri streamflow-gaging station. The basin development factor produced results with slightly smaller average standard errors of estimate for estimating flood discharges; however, this study indicated that there was not enough statistical or numerical difference to warrant using the basin development factor instead of the percentage of developed area in Missouri. The selection of a basin characteristic to describe the physical conditions of a drainage basin will not depend solely on its contribution to accuracy of regression equations; it also will depend on which characteristic is easiest to obtain and percentage of developed area has this advantage. A correlation analysis was made by correlating drainage area to percentage of impervious area, the percentage of developed area, and the basin development factor. The results of the analysis indicated the three basin characteristics to be independent of drainage area and appropriate to use in multiple-regression analysis"--Abstract, pages 1-2.