THE EFFECT ON THE FLOW CONDITIONS OF CHINESE STURGEONS' SPAWNING SITES IN THE PROCESS OF PEAK REGULATION BETWEEN THE THREE GORGES DAM AND GEZHOU DAM

摘要

Chinese sturgeon (Acipenser sinensis Gray) is a kind of key protected fish in ChangJiang river. After the GeZhou dam was built, the migration route of Chinese sturgeons had been cut off, the numbers of Chinese sturgeons are decreasing, and even so two new spawning sites were formed in the downstream of GeZhou dam with suitable flow conditions. But recently the Three Gorges dam has run, the peak regulation process between the two dams has serious effect on the formed spawning sites. Based on the previous research results of suitable flow conditions about the spawning sites, this article builds a 2-D shallow water numerical model, calculates the flow conditions of the spawning sites in the process of peak regulation. The results show that the water depth and velocity are various and affect the spawning sites in one 24-hour process of peak regulation, as a whole, when the discharge is below 9000 m~3/s and 7500 m~3/s respectively, the two spawning sites will be affected seriously.