Twenty Years River Training Works In Ghezel-Owzan River in Iran

Ghezel-Ozan River is one of the longest (670 km) and largest rivers of the Caspian Sea basin in Iran. The erosion of the riverside lands and destruction of the agricultural lands not only is a serious threat towards the economy of the nearby village, but also washes away huge volume of sediment into the Sefidroud Dam in downstream of the basin. Results of the flood control programme have been pointed 42 sensitive zones along the river need to implement river training. In a course of time, many river works had been constructed locally in some erosion zones. The investigations among these river works revealed that long groins (more than 80 meter) without any supportive dikes could not show good performance during the flood time. The experiences show that the group groins made by stone and maximum length 50 meter with distance arranging two times of groin length and supportive dike without any revetments are the best combination of structural countermeasure for this flood control programme. Investigations also show that implementing river training works only in one side of the river bank increases the possibility of erosion in the other side of river bank that was stable before river training works

Keywords:

River training , Groin , Scour depth , Flood control , Ghezel-Owzan River