Abstract

Water supply reservoir management is based on long-term management policies which depend on customer demands and seasonal hydrologic changes. However, increasing frequency and intensity of precipitation events is necessitating the short-term management of such reservoirs to reduce downstream flooding. Operational management of reservoirs at hourly/daily timescales is challenging due to the uncertainty associated with the inflow forecasts and the volumes in the reservoir. We present an ensemble-based streamflow prediction and optimization framework consisting of a regional scale hydrologic model forced with ensemble precipitation inputs to obtain probabilistic inflows to the reservoir. A multi-objective dynamic programming model was used to obtain optimized release strategies accounting for the inflow uncertainties. The proposed framework was evaluated at a water supply reservoir in the Hackensack River basin in New Jersey during Hurricanes Irene and Sandy. Hurricane Irene resulted in the overtopping of the dam despite releases made in anticipation of the event and resulted in severe downstream flooding. Hurricane Sandy was characterized by low rainfall, however, raised significant concerns of flooding given the nature of the event. The improvement in NSE for the Hurricane Irene inflows from 0.5 to 0.76 and reduction of the spread of PBIAS with decreasing lead times resulted in improvements in the forecast informed releases. This study provides perspectives on the benefits of the proposed forecasting and optimization framework in reducing the decision making burden on the operator by providing the uncertainties associated with the inflows, releases and the water levels in the reservoir.

中文翻译：

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基于集合的预测和优化框架，以优化防洪供水水库的排放量

摘要

供水水库管理基于长期管理政策，该政策取决于客户需求和季节性水文变化。但是，增加降水事件的频率和强度正需要对此类水库进行短期管理，以减少下游洪水。由于与流量预测和水库中的水量相关的不确定性，在每小时/每天的时间尺度上对水库进行运营管理具有挑战性。我们提出了一个基于集合的流量预测和优化框架，该框架由一个区域规模的水文模型组成，该模型强制使用集合的降水输入来获得到水库的概率流入。使用多目标动态规划模型来获得考虑到流入不确定性的优化释放策略。在飓风艾琳和桑迪期间，在新泽西州哈肯萨克河流域的供水水库对拟议框架进行了评估。尽管艾琳飓风预示着该事件的发生，但仍导致了大坝的超车，并导致了严重的下游洪水。桑迪飓风的特点是降雨少，但是，鉴于事件的性质，引起了人们对洪水的严重担忧。飓风“艾琳”流入量的NSE从0.5改善到0.76，PBIAS的传播随着交货时间的减少而减少，从而导致知情释放的预测得到改善。这项研究通过提供与流入有关的不确定性，提供了有关建议的预测和优化框架在减轻运营商决策负担方面的优势的观点，