Optimally integrating a reservoirs group and a flood detention basin for improving their flood control performance

Jingjiang flood detention basin and Three gorges (TG), Shuibuya (SBY) and Geheyan (GHY) reservoirs are located in the midstream and downstream of Changjiang River Basin. These reservoirs as a group and the flood detention basin are crucial to mitigate the extreme magnitude flood events in the midstream and downstream of Changjiang River Basin. This study proposed an optimal model to integrate the operation of a reservoirs group and flood detention basin rather than the current separately operations for improving their flood control performance. The operation schemes of an FDB sluices are enumerated for exploring the potential start time and end time of operating an FDB. The regulation of a reservoirs group is integrated with the operation of the sluices of an FDB. The impacts of the optimal FDB and reservoirs group flood control schemes on the flood control performance are quantified to gain insights on the difference between the FDB and reservoirs group flood control. The results and discussion indicate that synchronizing the operation of an FDB sluice-gate for the flood peak is better than the traditional rule for reducing the over flood volume. And the more flexible FDB flood control scheme can significantly improve the flood control performance. Therefore, our study will not only propose an optimal model to integrate an FDB and a reservoirs group, but also help to comprehend the mechanism of the reservoirs group and FDB flood control. • A model to integrate a flood detention basin (FDB) and reservoirs is proposed for improving flood control performance. • The impacts of FDB on flood control are quantified to understand the difference between FDB and reservoir flood control. • The ways of operating FDB affect flood control performance are explored.