Linear system theory-based optimization of detention basin's location and size at watershed scale

In the context of urbanization and waterworks construction, detention basins located in upstream tributaries have become one of the most-effective technical solutions for downstream flood reduction. This technical note proposes a new optimal approach for determining the most-effective design combination of detention basins (in terms of their sizes and locations) in a watershed utilizing linear reservoir theory. The optimal detention basin is obtained by minimizing the deviation of downstream peak discharge from river capacity discharge. With the presence of a detention basin in an upstream river, the flood peak downstream decreases by 33%, corresponding to two scenarios of rainfall duration with a return period T=100 years. The storage volume estimation of the optimal detention reservoir proposed in the present paper demonstrates the high applicability of this optimization approach.