Estimation and Zoning of Flood Risk Potential in Tehran Catchment Using Fuzzy Decision Model

Due to the natural conditions of Iran, ignoring the issue of floods can cause irreparable damages, among which flood estimation and flood zones zoning are of great importance in controlling the hazards. Due to the location of the catchment area in northern Tehran and the slopes and steep slopes, the precipitation and vegetation characteristics are one of the major concerns in this area. Also, the construction of villas and restaurants on the banks of the rivers and the destruction of vegetation have reduced the amount of infiltration water and increased surface water. The large volume of water on the one hand increases the magnitude of the flood inundation and on the other hand, with increasing erosion, it creates sediments that, by leaving them, reduce the capacity of the main riverbed. The main cause of these floods is heavy rainfall, sometimes accompanied by snow melting, causing flooding of the river and water flowing into the marginal lands of the river. In this study, we tried to study and zoning flood catchment areas in north of Tehran province using fuzzy decision making model. After analyzing the required fuzzy criteria each of them has been performed for zoning using gamma, or and and fuzzy information layers and for identifying catchment areas of gamma catchment catchment (0.8). Well highlighted flood-prone areas. The and operator extracts the maximum membership degree and does not have high accuracy in locating. Orger is also a collection sharing operator. As such, it extracts the minimum membership degree, thus making it very desirable for the present investigation of the gamma operator in relation to catchment hazard zoning.