This study will help improve the understanding of the hydrologic relations in the South Florida Everglades area, and will provide improved analytical tools to the water-resources community. Understanding the relation between rainfall and resulting runoff is important for accurate prediction of the risk of flooding. Many computer-based models have been developed to simulate this relation, but they need significant improvement to better describe how factors such as land use, soil properties, and rainfall distribution affect runoff. The USGS, in cooperation with the Illinois Department of Transportation, is using geographic information system technology to improve the way that models handle the various factors involved. Improved model simulations will provide better predictions of runoff and enable forecasters to provide more accurate flood information.
Damage caused by floods is especially acute in highly urbanized watersheds.
Yet the predictive tools used to estimate the potential effects of flooding are least accurate in urban areas because of rapidly changing land-use activities. The methods will provide better information for protecting existing structures and for planning future development. These studies and similar work nationwide have resulted in a USGS report that provides the means by which to estimate the magnitude and frequency of floods at ungaged sites on streams. The equations in this report are widely used by consulting engineers and government agencies for flood prediction. During the 1993 Mississippi River floods, USGS field personnel made more than 2,000 visits to streamgaging stations in the flood-affected areas to verify that the instruments were working and communicating properly, to make repairs as needed, and to make direct measurements of the streamflow.