Vulnerability assessment of urban areas against flood risk using Fuzzy logic and CIS. Case study: The 3rd district of Tehran

Iran and particularly its major cities, including areas that are frequently exposed to natural hazards. The main goal of this paper is to evaluate the vulnerability of urban areas in the metropolis is the risk of flooding. Review criteria for vulnerability assessment, including privacy River watercourse, structure, direction and width network, land use, buildings and power density of the overall flood disposal area. In this context, to actually evaluate the results of vulnerability, the third major area of Tehran imprisoned, because of the Darband river and its watercourse, residential and high population density, composition of new tissue and worn, and a significant slope as the sample selection was. Research in this article, analytical and descriptive statistics with emphasis on attitude is a system. Thus, first using precipitation data from stations based in the region adjacent to the area desired and trend analysis addressed climate change and maximum discharge from each basin and rational methods to help curves, Intensity, Duration, Frequency station Mehrabad and Saadabad for 25 and 50 year periods were calculated. Using Fuzzy Logic level vulnerability of buildings and residential units to each assessment criteria and finally all the criteria together the final amount of vulnerability and the percentage has been calculated. The results show that three regions susceptible to the risks of failure to observe flood and privacy watercourse, building low resistance, high coefficient of runoff in residential areas, high density and narrow the number of classes being the most important communication network in the region vulnerable and more than 12 percent of the study area is quite vulnerable.