Effective Factors in Flood of Esfahan-Sirjan watershed Employing Factor Analysis Method

It is emphasized that control and reduction of effective factors of flood formation and intensification with the aim of flood discharge is one of the important principles of soil and water resources management in order to prevent destructive flood damages. In this regard, investigation and identification of the most important factors that influence flood formation and intensification in great watershed of Esfahan-Sirjan, located in Iran central district (with area 99300 square kilometers), was carried out, using revised records of 14 gauged flood discharge station by utilizing factor analysis statistical technique. In this study, effective factors in flood was determined and calculated; they include topography, climatology, soil, geology, plant cover and land use of studied sub-basins. Results of factor analysis application show that time of concentration, catchment slope and drainage density of 1 order streams with 37.9%, 29% and 24.6% weighed impact, respectively, are the most influential factors in flood formation and intensification in the study area. Thus, for optimum management of soil and water resources conservation in watersheds, it is necessary to investigate practical and scientific methods in order to reduce negative impacts of these factors on flood phenomenon in the studied sub-basins.