Prioritizing of effective factors in flooding potential using Electre IIIMethod and Flood Flow Coefficient (Case study: Sarkhoon Subwatersheds of Bandarabbas)

More than 75% of Iran is located in arid and semi-arid areas. These areas have intensive and irregular distribution rainfall. Most rainfall exit from these areas as flood waters. Exact estimation of flood-water peak discharge and prioritizing the flooding potential in necessary in every subwatersheds although because of economic restriction, watershed restoring is not practicable in all subwatersheds. This study was done in Sarkhoon watershed of Bandarabbas in south of Iran that located in arid areas in Iran. For flooding prioritizing in subwatersheds we used of Electre III method (that is one of multicriteria method( and flood flow coefficient formula. For enter the information, based the viewpoints of experts and references review, 7 criteria was selected that includes: Basin mean weight slope, gravilus coefficient, permeability, runoff coefficient, shape coefficient, vegetation cover and rainfall intensity. Then the criteria weights was calculated using AHPmethod and for select the best hierarchy and function of electret and flooding coefficient, we used of spearman correlation (r=0.85) so using of ElectreIII method can be a good method for flooding potential in these subwatersheds, finally for final ranking we used of combination method. Results showed that suwatersheds 18-1-1, 14 and 18-1-2 are under severe flooding in comparison with other subwatersheds.