Study on joint flood control operation for leading reservoirs in the upper Changjiang River

The Changjiang River possesses a complex river system and widely distributed flood protection objects. As the multi-nurpose of flood control operation for its leading reservoirs involving a wide range of regions, the key for joint flood control operation of leading reservoirs in the river basin lies on utilizing flood control storage reasonably and orderly giving consideration to overall plans flood control for related regions. Taking a group of reservoirs, Xiluodu, Xiangjiaba and the Three Gorges as the object, this paper proposes flood control storage allocation plan for coordinative flood control of the Chuanjiang and the Changjiang rivers by using the principle of large-scale system decomposition-coordination, through successively decomposing the different demands for the flood control storage of Xiluodu and Xiangjiaba reservoirs by the flood protection objects in every region, and analyzing flood strike patterns for the Chuanjiang River and the midstream of the Changjiang River. Further, a flood control operation mode of the Three Gorges reservoir was optimized and an allocation plan was raised by increasing flood control compensation storage for Chenglingji, concerning impoundment effect from upstream Xiluodu and Xiangjiaba reservoirs. The results show that the joint operation mode can further reduce flood diversion capacity of the lower-middle reaches of the Changjiang River, which is highly significant for increasing flood control capacity and improving comprehensive group-reservoir flood control system of the whole Changjiang River Basin.