Reasearch On The Effect Of Low Temperature Water From Zaoshi Rerservior For Influence On Downstream River

In this thesis, studied on the reservoir water temperature and downstream river temperature after the completion of Zaoshi Dam in HuNan, we aimed to understand water temperature distribute. And evaluation of whether changes in water temperature downstream is really bad impact, if there is, advice to take the corresponding ecological compensation measures. The main conclusions are summarized as follows:1) Water temperature was observed on Zaoshi reservoir and downstream river for 3 times in May, July and November 2010. Observed water temperature In May, July, and November:Water temperature gradually decreased as the water depth increased; have a little change at the same period; vertical water temperature observations in different months have some degree different. Water temperature along the river had a slight change in May, July, November. In May and July along the water temperature increased, little change in November; a smaller change in river water temperature of each section at the same period; average temperature different in different month.2) At First analyzed the feasibility of the empirical method applied for Zaoshi Reservoir, select a better method between ZhangDaFa Method and Mathematical Method to calculate the vertical water temperatures of Zaoshi reservoir, and reached a preliminary rule of water temperature of Zaoshi Reservoir;The results show:November to next March the water temperature vertical evenly distribution; April to October, the water temperature was vertical stratification; form May to September the difference between the surface and bottom temperature is greater than 10℃, in April, October vertical difference greater than 5℃.3) The river downstream temperature of Zaoshi was calculated by the one-dimensional model of water flow and temperature. In those months October, November, January, February, March July water temperature from the dam site to Three estuary is±1.4℃, December slightly lower along the way, the reduction was small; The changes in other month temperature is more 1.5℃above, change greatly, the maximum difference in June,2.6℃. For the full year, when the temperature is lower than the water temperature, the temperature decreases slightly along the way; when the temperature is higher than the water temperature, the water temperature increases along the way. While the temperature and the temperature difference are large, the water temperature changes larger along the way.4) At last impact analysis on rice and fish. The relust is no really bad impact on irrigation when using the reservoir water. But the water temperature has a great impact on the fish. So we suggest the government to take measures to slove the problem.