بررسي كارايي هيدروگراف واحد لحظه اي ژيومورفولوژيك و ژيومورفوكليماتيك در برآورد دبي سيلاب

The Efficiency of Geomorphologic and Geomorphoclimatic Instantaneous Unit Hydrograph Models in Estimating Flood Discharge

Among the main objectives in hydrology are to quantitively forecast the process of rainfall-runoff, and to determine flood discharge at the outlet of a watershed. Flood discharge can be estimated using rainfall-runoff models which explain hydrological phenomena for ungaged watersheds. If the dimensions of flood hydro graph (which is the result of the watershed response to rainfall) are known, then the importance of models which are based on geomorphology of a basin will be very clear. The purpose of this study is to investigate the consistency, accuracy and reliability of geomorphological and geomorphoclimatical models in estimating the shape and discharge of flood resulting from a rainfall with certain intensity and duration. The results of these two models were compared with Nash, Rosso and SCS models. The results showed that the efficiency of geomorphologic model ratio to geomorphoclimatic, Nash, Roso and SCS are 106.56, 171.12, 106.79 and 112.64 percent respectively, and that geomorphoclimatic model ratio to Nash, Rosso and SCS is 106.57, 100,21 and 105.69 percent, respectively. Therefore, the result of geomorphologic model compared to other models (based on this study) is the most efficient model to estimate flood discharge.