Flood vulnerability of the Karun River System and short‐term mitigation measures

Abstract K arun R iver B asin in south‐west of I ran has accommodated a large number of hydro projects including reservoirs, hydropower plants, water convey systems, and irrigation networks. Recent extreme floods of the basin have resulted in damage to the vulnerable flood plain areas and under‐construction dam sites. Structural and non‐structural approach was pursued to reduce the vulnerability of the region after extreme floods of 2005 and 2006. The paper describes the historical floods and the solutions that were recently implemented in the basin. Resistant cofferdams along with early flood forecasting system ( EFFS ) and emergency action plan ( EAP ) have been identified as adoptive short‐term solutions. The EFFS incorporates a regional numerical weather forecast system, rainfall–run‐off models, a reservoir flood control simulation model, flood routing, and two‐dimensional inundation models. Depending on the location of the sites, maximum lead time of forecast is 4–5 days, which is sufficient to evacuate the area and damage centres. An EAP was made for dam break and extreme flood events including maps of hazardous zones and access maps to safe areas in the damage centres, mainly in the large cities of the flood plain area.