Investigating influence of storage dams construction on downstream flood reduction in Juneghan-Farsan watershed with respect to their local distribution

Flood can produce huge damages in different regions of Iran and all contries around the World and also destroyes soil and water resourses every year.There for, any type of principal and useful method for flood reduction and control should be applied in various regions and watersheds. Juneghan-Farsan catchement is one of the watersheds of Chaharmahal and Bakhtiary province. In this basin, various dams is under construction or ongoing study and in this paper we try to assess the influence of storage dams construction on downstream flood reduction via flow routing modeling. The results showed that the construction of all of the dams in Juneghan-Farsan basin will reduces minimum the maximum flood discharge in downstream up to 34 percent. This value is increased with reduction of flood return period. Also the results showed that the off stream dams would be less efficient to reduction peak flood discharge. Due to increasing length of spillway, there is not observed significant flood reduction. The reduction rate was obtained averagely about 0.6 percent.

Investigating influence of storage dams construction on downstream flood reduction in Juneghan-Farsan watershed with respect to their local distribution Keywords:

Reservoir routing , Stream flow routing , peak discharge , Flood control , HEC-HMS model