Study on multi-level optimization of reservoir drought-limit water levels for extreme droughts
The drought-limit water level,as a key indicator for drought warning and response,plays a significant role in water resource management.In light of the challenges that the current drought-limit water levels is difficult to effectively cope with multi-year consecutive and extreme droughts,as well as the underutilization of dead storage capacity as an emergency water source for drought resistance,this study divided the drought-limit water level of the reservoir into four developmental stages:"initial proposal-staging and classification-optimization of control period-tapping potential to increase supply".A new method was developed to determine the drought-limit water levels considering the activation of dead storage capacity,and a multi-level optimization approach was proposed to im-prove the effectiveness of reservoir drought-limit water levels in handling various degrees of drought,particularly multi-year consecutive droughts.Through a case study of the Qingshanzui Reservoir in Chuxiong,Yunnan Prov-ince,the feasibility and rationality of this approach in dealing with severe droughts has been verified.The results show that the low drought-limit water level scenario reserved for one hydrological year can effectively alleviate water shortages during drought years by reserving water in advance.On this basis,by extending the drought response scheduling period and considering the activation of dead storage capacity,two optimized scenarios were set up:one reserving water for two hydrological years without utilizing dead storage capacity and another doing so with its utiliza-tion.The results indicate that the scenario reserving water for two years and utilizing dead storage capacity further reduces water shortages and their periods across sectors during severe drought.Compared to the current scheduling situation,this optimized scenario increases the water supply security degree during typical consecutive low flow years from 78.5％to 94％,reducing the imbalance in monthly water supply security degree.The monthly water shortage can be reduced by up to 5 million m3,effectively decreasing irrecoverable severe water shortages.This study provides an optimized approach for drought-limit water levels aiming to enhance drought-resistant ability and offers scientific basis and technical support for decision-making in severe drought defense.
drought-limit water leveldroughtdead storage capacityoptimizationQingshanzui Reservoir
万方数据
维普
