Floodway System Operation along Levee-Protected Rivers

Abstract

Floodways may offer efficient flood damage reduction along flat land rivers, especially if the real-time operation of the floodways is feasible. Given an observed or forecasted upstream flood hydrograph, an optimal control policy of floodways is sought that results in the least flood damage over the whole system. The system consists of a river protected against flooding by existing levee reaches and floodways. The levee reaches are characterized by variable and uncertain levee resistance due to soil heterogeneities. This uncertainty is modeled probabilistically, leading to levee resistance performance functions. A model is developed to calculate failure probabilities for a river section consisting of several levee reaches. The objective function aims at minimizing expected flood losses along all river reaches to determine daily floodway operation. Results for the Tisza River system in Hungary indicate the benefit of using the optimal control policy versus other possible schemes.