Micro-zoning vulnerability of cities against flood risk (case study: Tabriz city)

Flooding and floodwater is one of the most important environmental hazards that can lead to severe damage such as mortality and have long-term economic and social impacts. It may even damage the property, disrupt the communication system, and wash agricultural land. Tabriz city placement in Lake Urmia basin, its plain position, and passage of two main rivers of Aji Chay and Quri Chay from the city has caused many destructive floods to take place and left great deal of ruin. This research aims to explain the geographical situation of Tabriz city and analyze its action against urban floods with a descriptive-analytical approach. ARCGIS 10.5 and Topsis-fuzzy model is used to evaluate the research criteria. After reviewing the research literature and the related studies, five criteria were selected as the main criteria of the research. Then, the distance between positive and negative ideals for the criteria was determined by using Topsis-fuzzy model; finally, the spatial classification of criteria was extracted by mapping each of the criteria. According to the final map, that shows the vulnerable areas of Tabriz city against flood risk, 6% of the city's area with a population of about 91277 people is in very high-risk zone. Considering very high to medium risk areas, 33 percent of the city's urban area, about 46 percent of the city's population are at risk of flood. This indicates that flood-prone areas are crowded and populated areas of the city.