A study on, utilization of cooling capacity of hypolimnion and evaluation of water quality improvement in a reservoir

点击翻译按钮获取中文摘要

In period of thermal stratification of deep. reservoirs, part of cool water of hypolimnion can be expected as energy resources for cooling especially in the summer season. In order to prevent water quality problems in the reservoir such as eutrophication etc., vertical mixing methods such as aeration are available. The concept of new method in this study is to utilize the cooling capacity of hypolimnion and also to improve the water quality by vertical mixing using the pumping systems. Through the feasibility study on a reservoir in Saga Prefecture, it is demonstrated that the estimated total cooling capacity, 2.1 X 10^8MJ/10^7m^3 (cool water of hypolimnion), can keep air volume of 10^5m^3 at 20℃ from May until October. In order to evaluate water quality improvement using this method, one-dimensional water quality model is developed. After calibrating the model for two reservoirs, effects of the water quality improvement by vertical mixing approach are evaluated. Also it is shown that the proposed technology have effect on water quality improvementt in the epihmnion in summer.