Abstract:

Stoplog intake works is often employed by large reservoir to improve discharged low temperature water in spring.However，current stoplog intake works in wholeyear service may intensify the discharge of the hightemperature water in winter and even influence water temperature in spring.This paper proposed a new regulation mode for stoplog intake works according to the demanding time of downstream fish the reservoir water temperature of Xiluodu Hydropower Station of the lower Jinsha River was studied.The result showed that stoplog intake works in different period of time improved water temperature efficiently and avoided high temperature in winter.The impact of cascade development on the performance of stoplog intake works was also studied.The reservoir regulation ability，cascade combined operation and operation caused the flattening of temperature in the inflow downstream reservoir.Besides，along with the transition water temperature structure of  Xiluodu hydropower station，the effect of stoplog intake works on water temperature apparently weakend.

Key words: large reservoir/cascade combined operation/ impact of low temperature water/ stoplog intake works