Spatially Varying Rainfall and Floodrisk Analysis

Abstract

A mathematical simulation model of the spatial and temporal rainfall process was developed. The model is used as input to distributed rainfallrunoff models in order to obtain streamflow series at multiple locations in large river basins. Frequency analysis under different basin development and control alternatives can then be performed. A case study in the Cumberland River Basin (Kentucky and Tennessee) is presented. The basin is $46\text{,}397{\mathrm{km}}^2\left(17\text{,}914{\mathrm{mile}}^2\right)$ and thus exhibits large rainfall variability in space. The rainfall model was calibrated with 28 yr of hourly and daily rainfall data in 274 stations in and around the basin. By using generated rainfall as input to a previously calibrated distributed rainfall‐runoff model, discharge frequency curves were obtained at 14 locations. The curves corresponded to both the system with eight operational flood control reservoirs and the natural system without regulation.