Optimal Reoperation of Multi-Reservoirs for Integrated Watershed Management with Multiple Benefits

Xinyi Xu,Lingling Bin,Chengzhong Pan,Aizhong Ding,Desheng Chen

doi:10.3390/w6040796

Abstract

Constructing reservoirs can make more efficient use of water resources for human society. However, the negative impacts of these projects on the environment are often ignored. Optimal reoperation of reservoirs, which considers not only in socio-economic values but also environmental benefits, is increasingly important. A model of optimal reoperation of multi-reservoirs for integrated watershed management with multiple benefits was proposed to alleviate the conflict between water use and environmental deterioration. The social, economic, water quality and ecological benefits were respectively taken into account as the scheduling objectives and quantified according to economic models. River minimum ecological flows and reservoir water levels based on flood control were taken as key constraint conditions. Feasible search discrete differential dynamic programming (FS-DDDP) was used to run the model. The proposed model was used in the upstream of the Nanpan River, to quantitatively evaluate the difference between optimal reoperation and routine operation. The results indicated that the reoperation could significantly increase the water quality benefit and have a minor effect on the benefits of power generation and irrigation under different hydrological years. The model can be readily adapted to other multi-reservoir systems for water resources management.

Highlights

Reservoirs and dams are the most serious anthropogenic effects on riverine ecosystems [1]
We developed a reservoir optimal reoperation and evaluation framework for multiple reservoirs, which takes into account economic, social and eco-environmental benefits with overall planning ideas on the basin scale
The runoff distribution results in three hydrological years with various inflow conditions were derived according to the objectives and constraint conditions (Figure 4)

Summary

Introduction

Reservoirs and dams are the most serious anthropogenic effects on riverine ecosystems [1]. Many of the world’s major rivers have become ladder-type river systems, whose flows are punctuated by reservoirs. The construction of reservoirs is the primary way that humans manage water resources for water supply, power generation, flood control and irrigation and to alleviate the increasing disparity between water supply and demand. On the other hand, constructing a reservoir significantly changes the natural river runoff process and destroys the dynamic equilibrium of the river ecosystem, resulting in problems of eutrophication in reservoirs, increased soil salinity downstream from dams, sediment deposition in dams, shrinking of the delta, deteriorating water quality and other adverse effects [2].

Methods

Results

Conclusion