Analysis and Evaluation of the Integrated Effects of the River Regulation Project at Nanjing's Xinjizhou Reach

The Xinjizhou Reach of the Yangtze River in Nanjing, as the first section of the river entering Jiangsu Province, features complex river regimes and frequent shoal development, with historical occurrences of bank collapses seriously impacting flood control safety and regional development. To stabilize the river regime and enhance flood control capacity, systematic regulation projects were implemented from 2013 to 2018, including the construction of flow-guiding dams, middle channel blockage, and bank revetment reinforcements. After the project implementation, the river regime of the Xinjizhou Reach has stabilized, the flow division ratio between the left and right channels has been effectively regulated, and ecological functions have significantly improved, with a notable recovery in wetland biodiversity. However, influenced by the ongoing changes in the flow division ratio of the upstream Xiaohuangzhou Reach, local instability persists, manifested as expanding scour pits and frequent bank collapses. It is recommended to strengthen long-term monitoring and promote coordinated management of upstream and downstream sections to ensure the long-term safety and effectiveness of the project.