Using the fuzzy inference system and morphometric indices, in finding the vulnerable areas to the earthquake

Every year many earthquakes occurs around the world and some of them are highly destructive. Therefore, the study of the vulnerable areas to the earthquakes seems crucial. Current paper presents a novel method for the assessment of areas, which are prone to the earthquakes, using relative tectonic activity index (IAT). IAT is calculated via six morphometric indices, including Asymmetry factor, Mountain Front Sinuosity, Valley Floor width, Hypsometric Integral, Average of Channel Mean Slope and Drainage Basin Shape. Every index has some limits to show the magnitude of tectonic activity and sometimes they are not clear enough and need a reliable and accurate scoring method to reduce the uncertainty of the calculation results. Morphometric Indices, as the key factors in determining the tectonics situation of an area, were analyzed via fuzzy inference system to improve the accuracy of decision making in the IAT calculation, as the suggested method in present paper for the earthquake vulnerability assessment. Torbat-e-Jam basin was selected as a case of paper to operate the proposed method. Results showed that about 0.87 percent of paper area has the high IAT and is high risk of earthquake, consequently. About 82.47 and 16.66 percent of paper are determined as the moderate and low IAT, respectively. The map of the earthquake intensity of the paper area was plotted, afterwards, to check whether the results of presented method are reliable, and it approved that. The above method, thus, is applicable in those areas, which do not have enough seismologic data.