Capacity Assessment of the Vulnerability of Settlements in the Tahlab Watershed of Sistan and Baluchistan Through Accidental Floods

Flood is one of the destructive natural phenomena that has greatly affected human activities and human settlements. The current research was carried out with the aim of identifying settlements susceptible to accidental floods in the dry catchment area of ​​Tahlab in Sistan and Baluchistan Province. The research method is descriptive-analytical and practical in terms of purpose. Twelve indicators of the capacity to measure the risk of settlements are: road, settlement, soil, slope, height, precipitation, vegetation, geology, land use, main waterway, secondary waterway and drainage density of the collective basin. were brought. In the following, they were modified using the opinion of experts and were analyzed in 3 stages. In the first step, the importance of the data was evaluated using the ANP method in the Super Decision v2 software environment from 1 to 9. In the second step, in the Arc GIS 10.7 environment and based on the level of importance, each layer was classified into 4 high-risk, low-risk, medium-risk and no-risk classes. In the third step, using the weighted overlay tool, the flood risk zoning map of the Tahlab catchment area was prepared. The results showed that among the above 12 layers, the main waterway, slope, land use and precipitation would play the most important role in determining the flood risk potential of the research area. According to the findings of the research in risky areas, 24 settlements out of a total of 68 settlements are located in the range of high-risk potential to very high flood risk. Thus, It is necessary to use structural methods (water retention time program) and non-structural methods (warning system based on flood prediction models) in order to reduce the risk of flooding in these settlements.