Ecological flow requirement for Chinese sturgeon spawning habitat

Tennant method is used to attain the ecological flow requirement for Chinese sturgeon spawning habitat on the downstream of the Gezhouba Dam based on the analysis on hydrological data in recent 20 years.The results show that the optimal range is about 7 800～13 000 m3/s.Then,based on the survey topographic and hydraulic data,Instream Flow Incremental Method is used to make a further simulation for water depth,velocity and substrate.Habitat suitability index and GIS technique are used to connect the hydrodynamic model and biological characteristic of Chinese sturgeon to obtain the fish habitat area as a function of stream flow for the spawning habitat.The result indicates the optimal flow range for spawning habitat is about 5 000～15 000m3/s,which is validated with the surveyed flow in the spawning date annually.When the outflow is from both the Dajiang power plane and Erjiang power plant of Gezhouba Hydropower Station,the area of the spawing hahital is largest.