Stochastic Multistage Multiobjective Water Allocation with Hedging Rules for Multireservoir Systems

Abstract

In this study, a multiobjective multistage stochastic mixed-integer quadratic model for water allocation with hedging rules is proposed and investigated. Hedging rules determine different rationing levels among users at certain trigger volumes of reservoirs during droughts. The goal of this study is to provide a water management policy that could alleviate the water shortages caused by droughts and uneven distribution of rainfall in a region with multiple reservoirs. We devise a stochastic mathematical model to determine hedging rules under inflow uncertainty and apply an improved version of the augmented ϵ-constraint method to generate the Pareto frontier of two negatively correlated objectives. A real-world case study on the Taizi River Basin in China and numerical comparisons of the proposed stochastic model with other ways of handling uncertainty used in the literature (1) demonstrate the value of the proposed model; and (2) emphasize the importance of adequately considering the uncertainties and multiobjectives in managing multireservoir systems subject to droughts.