The Assessment of River Habitat on Water Temperature and Hydrologic Alteration of De-Watered River Channel in Flood Season

Water temperature and hydrological regime alteration cased by diversion-type hydropower station in de-watered river reach have noticeable impacts on river habitat. This paper evaluates the influence of hydrological regime alteration in flood season and water temperature alteration based on daily average streamflow data(1985-2014) from Santan hydrologic station and daily average water temperature data(2005-2015) from Huning hydrologic station. The results show that the hydrological regime had been changed significantly, water temperature is about 1.4°C(-0.35-4.3°C) higher than nature state in winter while about 0.6°C1.4°C(-0.35-4.3°C) higher than nature state in non flood season while about 0.6°C(–1.7-2.6°C) (–1.7-2.6°C) lower in flood season. It concluded that biomass reduction would happened, hydrostatic organism would be increased and the eco-system of Dahewan loop had been effected by the hydropower station operation.