Global flood modeling: statistical estimation of Peak-flow magnitude

United Nations Environment Programme (UNEP) (2006)

The scope of the present paper is to describe an exploratory analysis on the feasibility of a global flood hazard modeling, which would enable further studies on human vulnerability. The method chosen is inspired by local peak-flow magnitude estimations realized in the U.S. After determining -by GIS-processing- for each HYDRO1klevel 4 basin a set of hydromorphometric and climatic values and the coordinates of a corresponding gauged or ungauged outlet station, peak flow magnitude for gauged stations are estimated using log-Pearson type III distribution, following the directions of Bulletin 17B from USWRCs Hydrologic Subcommittee. Estimates of peak flow magnitude for ungauged stations are then obtained by statistical means, performing several regressions on the basin variables. Peak-flow magnitude estimates enable the computation of corresponding flooded areas using Mannings equation and GIS processing. This regression method is processed on two test-zones situated in North and South America.