Research on hydrological impact on spawning grounds of fish in reservoir area by Gushan Hydropower Station

After the completion of Gushan Hydropower Station on Hanjiang River, the hydrological regime in the reservoir area will change and the fish resources in the reservoir area will be affected. This paper adopts 1D hydrodynamic model to simulate hydrological regime before and after construction of Gushan Hydropower Station and based on the simulation results, analyzes the hydrological regime changes at the estuaries of Baihe River and Jiangjunhe River spawning grounds of fish with pelagic eggs. The results show that the daily average water level and water surface width in the reservoir increase in varying degrees, and the flow rates decrease from the reservoir tail to dam site. At estuaries of Baihe River and Jiangjunhe River, the water levels rise 7m and 15m, and the flow rates decrease to 0.11 m/s~0.14 m/s,0.08 m/s~0.09 m/s, the surface widths increase by 33~49 m,104~150 m respectively, which reveals that the hydrological regime of fish spawning grounds change significantly. The fish spawning conditions show that ecological environment of fish spawning ground will be severely affected, which will lead to decline in spawning amount and efficiency. For this reason, after the reservoir is constructed, the corresponding countermeasures should be taken to protect the local fish resources.