2 Study area
The Jingjiang River is approximately 340 km long, flowing from Zhicheng to the mouth of Dongting Lake located in Chenglingji, and it is divided into two reaches. The upper Jingjiang extends from the Zhicheng reach to Ouchikou, with a lightly curved braided river flowing over 171.5 km, while the lower Jingjiang starts at Ouchikou and ends at Chenglingji, with a typical meandering pattern approximately 175.7 km long (Fig. 1). In this paper, Zhicheng, Shashi, Jianli and Luoshan hydrological stations are selected to analyze the channel connectivity of the Jingjiang River.
The Gezhouba Water Conservancy Project is located 38 km downstream of the TGD and 64 km upstream of the Zhicheng hydrological station, and this project is the first large-scale run-of-river hydropower station on the Yangtze River with low-head and high flow. In addition, the impoundment of the TGD was finished successfully in 2003, and it is the largest water conservancy project in the world, with a total storage capacity of 39.3 billion m3.