Flood Management in Kan River Basin Using a Simulation- Optimization Approach

Weaknesses of the conventional flood management approach, lack of integrated view to the basin, no attention to the social impact, and low level of non-structural measure considerations, have the reason for a new approach to integrated flood management. Applying the new approach, this paper proposes an effective plan for flood management in the Kan River basin, north of Tehran. The main challenges in the study are quantification of social vulnerability and selection of optimal combination of feasible measures such a way that maximum potential of damage reduction be achieved while the least funding be spent. Therefore, flood flow with 100 yr and 200 yr return periods was simulated applying MIKE11 coupling with NSGA-II to minimize the implementation cost. Based on the prepared model, various combinations of applicable methods were proposed considering different level of fund allocations. Results showed that out of structural measures flood wall and retention dam and out of non-structural measures watershed management, reinforcement, and flood warning have been the most effective measures. The optimal combination of these measures can reduce 2 to 50 percent of flood peak discharge at downstream. Moreover, the obtained results showed that about 100 billion Rials investment in the basin would reduce up to 30% flood damage.