College of Land Science and Technology, China Agricultural University, Beijing, China.
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China; Key Laboratory of Sediment Science and Northern River Regulation, Ministry of Water Resources, Beijing, China; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China.
J Environ Manage. 2022 Apr 15;308:114582. doi: 10.1016/j.jenvman.2022.114582. Epub 2022 Feb 2.
Small hydropower (SHP) possesses significant economic, technical, and environmental advantages, and accounts for a large proportion of hydropower development in China. However, the concentrated, cascaded, and diversion-type development of SHP has resulted in long-distance dewatering of river sections, and inter-basin water transfers have led to severe exploitation of water resources and damage to river ecosystems. In this paper, the Datong River Basin, a secondary sub-basin of the Yellow River Basin in China, was selected as the illustrative case, which includes 22 hydropower projects (HPPs) and three inter-basin water diversion projects (WDPs). A nexus system model was established that used weighted multi-objective programming to consider three main objectives: the water resources utilization (local water withdrawal and inter-basin water transfer), energy production (by cascaded HPPs), and riverine environmental conservation. The Tennant method was used to estimate the environmental flows (e-flows) at the cross-sections immediately downstream of the dam/sluice gate and immediately downstream of the hydropower plant of diversion-type HPPs. The decreased percentage of regulated flow in comparison with runoff and the guaranteed rate of e-flow at the control cross-section were introduced to assess the degree of environmental impact to the river. Using a historical series of runoff data during 1956-2016 as the model input (i.e., implicit stochastic method), the Multi-start solver of nonlinear programming of LINGO software was used to conduct optimizations and analyses for multiple scenarios (with/without e-flow, with consideration of various levels of e-flow, and with/without water resources utilization). The sectoral linkages relating to the water-energy-ecosystem (WEE) nexus were quantitatively identified. The possible influences of different boundary conditions (i.e., initial/final reservoir storage, inter-basin water diversion capacity, and climate change) on the WEE nexus were further explored. The present study aims to provide an exemplar for the optimal operation and scientific management of a complicated water resources system in a regulated river with cascaded SHP and inter-basin WDPs.
小水电（SHP）具有显著的经济、技术和环境优势，在中国的水电开发中占有很大比例。然而，SHP 的集中式、级联式和引水式开发导致了河流部分的远距离排水，跨流域调水导致了水资源的严重开发和河流生态系统的破坏。本文选择中国黄河流域的二级子流域——大同河流域作为实例，该流域包括 22 个水电站（HPP）和 3 个跨流域调水工程（WDP）。建立了一个枢纽系统模型，该模型使用加权多目标规划来考虑三个主要目标：水资源利用（当地取水和跨流域调水）、能源生产（通过级联 HPP）和河流环境保育。田纳特法用于估计引水式 HPP 大坝/水闸下游断面和水电站下游断面的环境流量（e-flow）。与径流量相比，调节流量的减少百分比和控制断面的保证 e-flow 率用于评估对河流的环境影响程度。利用 1956-2016 年期间的历史径流系列作为模型输入（即隐式随机方法），LINGO 软件的非线性规划多启动求解器用于对多个方案（有/无 e-flow，考虑不同水平的 e-flow，有/无水资源利用）进行优化和分析。定量识别了与水-能-生态系统（WEE）枢纽相关的部门联系。进一步探讨了不同边界条件（即初始/最终水库储存量、跨流域调水能力和气候变化）对 WEE 枢纽的可能影响。本研究旨在为具有级联式小水电和跨流域调水工程的受调节河流复杂水资源系统的优化运行和科学管理提供范例。
