Study on cumulative effects of water temperature by cascade hydropower stations built on rivers

The Article introduces the situation of water temperature structure in cascade hydropower stations built in middle and lower reaches of rivers,analyzes the effects due to cascade hydropower development in river basins,by means of combining field observation with numerical computation.Furthermore,the cumulative temperature effects of discharging water from reservoirs are simulated.The research result indicates that high dams with large reservoir would make significant change of river flow temperature and lead to a big cumulative effects on water temperature.The more a river basin is developed,the larger the effects would be.Some quantitative results are obtained,which would provide a reference for large scale hydropower station operation in order to reduce cold water discharge effects on water temperature.