Zoning of Flood-prone Areas Using Geographic Information System (GIS) and Remote Sensing (RS), (Case Study: Darab City)

Abstract

Natural hazards are unfortunate accidents that cause a lot of irreparable damage to the natural environment and man-made phenomena every year. Floods are among the hazards that have always been likely to occur as a natural hazard to humans. In the meantime, identifying flood-prone areas is one of the first measures to deal with them. Darab city was not isolated from this matter and this study was conducted to prepare a flood potential map of the city. Because many criteria are involved in flooding in any region. Therefore in this study 12 criteria including Slope, Aspect, Rainfall, Runoff Height, Curve Number status (CN), Flow Accumulation, Soil Hydrological Groups status, Land Use, Vegetation Density, Drainage Network Density, Basin Elevation, and Distance to Drainage Network, selected and maps were prepared for each. In the next step, the prepared maps were weighted using the Analytic Hierarchy Process (AHP) method and using Expert Choice software and their fuzzy process was performed by the fuzzy logic model. Finally, the overlap of the layers was performed using a fuzzy algebraic summation operator (SUM) in Arcmap software and thus maps related to flood risk zoning of Darab city with different return periods and on 5 floors were extracted. In maps obtained with different return periods, the pattern is almost identical and similar. According to the final plans, the risk of floods with return periods of 25, 15, 5, and 50 years, respectively 9.91, 9.39, 8.4, and 9.93% of the area of the city with flood risk Very low fertility and 9.24, 10.64, 11.90 and 8.65% of its area has a very high risk of flooding.