Reservoir operation impacts on floodplain wetland inundation and ecologically sensitive areas

The continuous construction of reservoirs worldwide has promoted socio-economic development and seriously affected the ecological and hydrological processes of rivers and floodplain wetlands. This study takes the Yimin River in Inner Mongolia, China as the research area, and based on the WIGR(Water inundation guarantee rate)model, quantifies the ecologically sensitive areas on both sides of the river under the operation of reservoirs, and proposes targeted protection suggestions. The research results show that due to the influence of reservoir construction, the areas with a WIGR of 0-20% are the most affected, with a reduction of 12.14 km² in area. The average offshore distance before and after reservoir construction is 1050 m and 1125 m; The extremely low sensitivity reduction areas (1-4%), low sensitivity reduction area (5-16%), moderate sensitivity reduction area (17-46%) and high sensitivity area (47-80%) are 21.73 km², 4.01 km², 2.71 km² and 0.18 km² respectively, and the offshore distances are 975 m, 990 m, 630 m and 180 m respectively; We suggest that future water conservancy hub construction should consider releasing water at specific times to mimic natural flow patterns, and incorporating wetland restoration and protection work into dam design and operation to reduce the impact of dams on the environment and promote sustainable use of water resources. This study can provide new ideas for quantifying and protecting ecologically sensitive areas in floodplain wetlands.