Determining Flood Origin Areas and Flooding Prioritization at a River Basin (Case Study: Lavidj River Basin, Mazandaran Province)

Applying appropriate flood control measures leads to decrease the flood damages. Identifying of flood origin areas is one of these measures. This study investigates to identify flood origin areas at Lavidj river basin located in Northern Iran using the rainfall-runoff HECHMS model. The final goal is prioritization of flooding for the river basin using the results of the study. By computing discharge from each hydrologic unit and river routing till the basin outlet and at the final step applying successive hydrologic unit elimination technique at each model run, contribution of each unit to the basin flood is determined. This leads to prioritize hydrologic units to apply proper flood control measures. Furthermore, to remove the effect of the area for each hydrologic unit, flooding prioritization has been done using area parameter. The results showed that hydrologic unit A has the most contribution in the basin discharge and it has the highest flooding potential in the Lavidj river basin.