The study of agricultural flood return period in Can watershed

Natural disasters have always endangered human lives. Flood is one of the most important natural disasters that impose many damages every year in different parts of Iran. This paper tries to study flood and characteristics of Can watershed in Tehran province. The main purpose of this paper is to consider the challenges of flood management in agriculture and provide appropriate strategies in order to flood risk management in Can watershed.

In this paper, using the GIS software, the flood return period of 5, 10, 25 and 50 years considering the agricultural land use in the watershed in north of Tehran will be studied. The risk level of 1 to 5 percent with an unimportant damage level, 5 to 10 percent with a low damage level, 10 to 15 percent with a moderate damage level, 15 to 20 percent with a high damage level, 20 to 25 percent with a very high damage level, and 25 to 30 percent with a destroying damage level was defined for Can watershed.

The results show that increasing the return period from 5 to 10, 25 and 50 will increase the damage in the basin. The 5-year and 10-year floods are expected a very low damage level; the 25 years flood is considered moderate damage level as well. Considering the destroying damage level, by the average 2.066 percent of lands, a 50 years flood is a moderate to destroying damage level.   

Considering the flood risk areas in order to flood risk management and development of watershed management plans, especially in agricultural lands in Can basin is necessary due to increasing the flood risk in recent decades in Can basin in Tehran.