Sustainable reservoir operations to balance upstream human needs and downstream lake ecosystem targets

Abstract

Abstract Reservoirs improve human health by providing a steady water supply, alleviate poverty by producing cheap electricity and strengthen regional economies by providing job opportunities. However, present modes of reservoir operation, without environmental flow targets, have caused ecosystem degradation while satisfying human needs. The degraded aquatic ecosystem conditions caused by tremendous dam construction in China propel a shift from an emphasis on human needs to sustainable modes of reservoir operation. In this paper, an optimizing reservoir operation model was developed to assist the decision making process of balancing human needs and ecological targets. The environmental flow regime paradigm and water shortage ratio of social water supply were respectively used to establish downstream lake ecosystem targets and upstream human needs. An Interactive Dynamic Programming (IDP) was developed to optimize the conflicts of human needs and ecosystem targets. A set of scenarios were designed for reservoir operations in the Baiyangdian basin in a normal year (50% percentage), a wet year (25% percentage) and a dry year (75% percentage), which provided a very useful tool for reservoir operations to balance human needs and ecosystem targets.