Zoning the Flood Risk in the Razi Chay Basin using the ANP Model

Research Aim:The watershed of Razi Chay located in Meshkin Shahr city is one of the areas of Ardebil province that is vulnerable to destructive floods. Therefore, investigation and zoning of flood in this basin is necessary. Research method: For this purpose, 10 variables affecting the occurrence of floods including: slope, aspect, elevation, distance from river, runoff height for maximum 24-hour rainfall, land use, vegetation, lithology, time of concentration and shape of the sub-basins were used. The analytical network process (ANP) was used to obtain the importance of each variable. Findings: Among the studied variables, the slope layers (with impact coefficient of 0.31), distance from river (with a coefficient of influence of 0.17) and runoff height (with a coefficient of influence of 0.12) yielded higher weight and, as a result of severe control on the occurrence of flooding in the Razi Chay watershed. The zoning results show that about 28% of the basin areais in high risk zones. Conclusion: These zones are mainly downstream of the basin and adjacent to main streams and flood plains around them. Regarding the spatial distribution of the settlements in the area, it can be said that most of the settlements located in the lower parts of the basin are subject to floods.