New Method for Flood Hazard Mapping in GIS (Case Study: Mazandaran Sub-Basins)

There are several approaches for flood prioritization and flood hazard mapping when it comes to flood subject, but the distributed and GIS-based methods are one of the best ones and widely used. On this basis, a new method which considers the interaction between the effective factors is used in this study. Finally, by using a linear combination the flood hazard map is created for the study area and divided into five classes including very high, high, moderate, low and very low. Verification of this approach by using recorded destructive floods at different hydrometric stations indicates that the performance of this method, especially on identifying areas with very high and high hazard levels, is very remarkable. For example, the results of distributed approach in Shirgah-Talar, Razan-Noor, SoleimanTange, Ghoran-Talar and Doab-Challos hydrometric stations are completely matched with recorded historical floods that most of them have the return periods higher than 50-year and 100-year.