تعيين مهمترين فاكتورهاي اقليمي و مورفومتري موثر بر دبي اوج و ارايه مدل رگرسيون در شرق و شمال شرق ايران

Important climatic and morphometric factors affecting on peak discharge and introducing a regression models (Case study: East and Northeast of Iran)

The identification of hydrologically homogenous regions is a primary step in many of regional flood frequency analysis techniques. This study was can-id out to determine the most important climatic and physical factors, which influence the watersheds in the east and northeast of Iran. The data of flood peak discharges and the characteristics of 16 basins in the study area were used. At first, test of the selected regional distribution function (Log Pearson type 111) was fitted and instantaneous peak discharges in different return periods were calculated. Independent and significant variables were selected using factor analysis method such as: basin area, mean elevation, drainage density and annual average rainfall. These variables explained 87.82 per cent of total variances. Hydrologic homogenous regions were also distinct using cluster analysis method. Comparison of the calculated RMSEs in two basins showed low errors among grouped regions.