As an important indicator and basis for early warning of drought,water shortages,and anti-drought planning in water conservancy projects,the drought-limited water level(DLWL)plays an important role in scientific guidance of the drought control of lakes.This study focused on the characteristics of controlled water supply lakes,while also fully considering the ecological health and stability of the lakes and combining with the reverse recursive calculation of lake utilization regulation.Thus,we developed a method for calculating the DLWL of controlled water supply lakes.The rationality of this method was verified through a case analysis of Erhai Lake,Yunnan Province,China.The results showed that the severe water shortage in drought years can be alleviated effectively by setting the DLWL and considering the minimum ecological demand of the lake.The maximum reduction in water shortage for the water supply of the region surrounding Erhai is as high as 10.23 million m3,and the maximum reduction in agricultural irrigation water from Erhai entering Binchuan County is as high as 10.16 million m3.Additionally,the water shortage rate and period in each industrial sector can be reduced significantly in areas around the lake.The time period during which the lake is below the ecological water level can also be reduced significantly.After setting the DLWL,the number of severe water shortage months for lake water supply and the Erhai water entering Binchuan County irrigation was reduced by 11 and 10 months,respectively,and the duration time below the ecological water level was reduced by 15 days.This study provides a general algorithm that can be used by flood and drought disaster prevention departments to establish a DLWL and guide the drought-relief operation of a lake,which can provide the scientific basis and technical support required for drought prevention.
关键词
旱限水位/控制性供水湖泊/生态需水/抗旱调度/洱海
Key words
drought-limited water level/controlled water supply lakes/ecological water demand/drought-relief operation/Erhai Lake
万方数据