Quantitative Assessment of Changes in Urban Runoff

The detection and quantitative assessment of the magnitude of man-induced changes in flood regimes in part of the Texas Gulf Coast are made using the method of trend surface analysis of distribution of storm runoff. The procedure incorporates the elements of frequency analysis and two- and three-dimensional synographic computer mapping. The natural geographic tendency in runoff distribution typical for the study area is compared with the runoff pattern induced by urbanization. The range of differences between urban and nonurban runoff found in this study is proposed as a guide for development planning in the coastal territories that are now primarily rural.