Evaluation of geomorphology method application for flood Hazards risk classification using Fuzzy Logic (Case study: Ojan Chay drainage basin)

Past decades damage by floods in Iran and on the other of the world has shown that we have still much work to do to cope with this problem. Hence، the study of these events and development of more effective adaptation and mitigation policies has become a priority، in other parts of the globe. First step in achieving flood risk assessment is data collection. Availability، suitability and quality of hydrological، meteorological، topographic and management data is discussed. This study combines a hydrologic and geomorphic data with aim of geographical information system to delineate the extent of a flood event in the Ojan Chay basin (98،227 km2)، one of the river system draining into the Aje Chay River. For This purpose، the 16- information layer has been prepared for overlaying using fuzzy sum and classified using Fuzzy C mean on the geomorphology data. The main objective of this research is to assess the flood hazard that affects Ojan Chay river basin، in order to develop a basis for further vulnerability and risk analysis. Flood hazard risk presented in the map because that give a more direct and stronger impression of the spatial distribution of the flood risk than other forms of presentation. The results of this study show that more than 70% accuracy (Kappa coefficient 0. 7502459) compared with reference data، indicating the acceptability of this method is the mapping of flood hazards.