PREDICTING TEMPORAL AND SPATIAL FLOOD DYNAMICS USING A PRECALIBRATED MODEL

A large storm in December 1990 allowed the evaluation of flood predict ions from a hydrologic model (TOPMODEL) that had been previously calib rated on the West Fork of Walker Branch Watershed, a gauged 37.5 ha ca tchment near Oak Ridge, Tennessee. The model predicts both hydrograph dynamics and the spatial distribution of overland flow using an index based on topography. Maximum extent of overland flow during the storm was determined from patterns of leaf litter removal from valley bottom s. Both the flood hydrograph and the extent of overland flow were accu rately predicted using model parameters obtained from a three-month pe riod of normal flow conditions during 1983.