Estimating the Level of Vulnerability of Informal Settlements in Tabriz City against the Risk of Earthquake

The purpose of this study is determining the most suitable method to evaluate the vulnerability of informal settlements in Tabriz city against a possible earthquake. ELECTRE FUZZY models and the WASPAS model were used in relation to 13 criteria (passage width, building quality, materials, the number of floors, distance from public open space, distance from urban facilities, distance from medical centers, population density, building density, distance from fault, geological type, plot area, land use) were compared. For this purpose, all informal settlements in Tabriz city were analyzed and the results of both models were evaluated by the authors’ field studies. Then, the most suitable method was chosen. The results of the research indicate that according to the WASPAS model, informal settlements located in Region 5 with a rank of 1 are the least vulnerable and region 10 is the most vulnerable with a rank of 6. Moreover, more than 57% of the area of informal settlements in Tabriz city are exposed to very high vulnerability, 11.05% are exposed to high vulnerability, 03.27% are exposed to moderate, and only 4.01% are exposed to low vulnerability. The results of the ELECTRE FUZZY model calculations indicated that the informal settlements located in Mentafah 3 with the rank of 1 are the least and areas 1 and 10 are the most vulnerable with the rank of 5. Moreover, more than 34% of the area of informal settlements in Tabriz city are exposed to very high vulnerability, more than 27% are exposed to high vulnerability, more than 25% are exposed to moderate vulnerability, and only 12.69% are exposed to low vulnerability. Based on the field studies of the researchers, the results of the ELECTRE FUZZY method are more accurate and realistic than the WASPAS method.