The Map of Kashafrud Catchments Prioritization in terms of Flooding Susceptibility Located in Khorasan Razavi Province Based on ELECTRETRI Algorithm

Flooding is one of the natural disasters which have effects most areas of the country and caused the loss of life and property; therefore, identifying of areas which are susceptible to flooding is one the most important measures in reducing losses. Classification and prioritization of sub-catchments is the first step to counter or mitigate the effects of flooding in the drainage basins. On this basis, the purpose of this study was to classify the flooding potential of sub-catchments of “Kashafrud” catchment in the “Khorasan Razavi” province by the use of ELECTRE-TRI Algorithm based on optimistic procedure and consistency control perspectives. To achieve this, the 1: 250,000 topographic map and waterways map of the target area were studied and area was divided into 10 sub-basins, then 8 morph hydrological parameters affecting the flooding potential including basin’s form factor, elongation ratio, circularity ratio, bifurcation ratio, drainage density, Mean basin slope and area were evaluated. After the evaluation, it was found that “Mashhad” and “Torghabe” subbasins had a high-risk of flooding because of the high value of drainage density and low value of bifurcation ratio in these areas, which both have a higher effect in flooding potential compared to other factors. Toos, Chenaran, Qazqan and sub-basins had a low risk of flooding because of the low values of the factors which increase the flooding potential and high values of the factors which decrease it.