基于系统动力学理论的复杂水库群工程体系调控下径流演变分析

Massive construction of reservoirs and hydraulic infrastructures indicates that human impacts intensify during the last decades. Consequently, streamflow observed at most of the gauging stations in the major large river basins in China shows a decreasing trend in annual volume and a homogenized regime in seasonal variations. The operation of reservoir system changes the natural streamflow hydrology greatly and alters the temporal and spatial distribution of water resources. Therefore, this study aims to investigate the impacts on streamflow hydrology induced by multiple reservoir operations, based on the study case of 20 large reservoirs upstream of Lutaizi located in the Huaihe river basin. Specifically, it covers the detection of reservor-induced changes on streamflow, system dynamics simulation of the changes and changes attribution. Compared with previous studies, the main contribution of the study includes: (1) the model of streamflow changes induced by reservoir operation based on system dynamics is drove by physical causes, the increasing water consumption and its interaction on the developing of reservoirs system, thus it is able to reveal the physical processes of streamflow changes; (2) the attribution and reasoning methods of streamflow changes induced by reservoir systems would be developed. The study applies an input-response analysis to discover the changes on streamflow and finds the critical reservoir and critical factor affecting the changes by system dynamics theory. Moreover, the effect of joint-operation mechanism among reservoirs would also be revealed. The study would provide new insights and methodology for understanding streamflow changes in a changed environment, and it would support the realization of efficient management and utilization of water resources.

近年来随着以水库水利工程建设为代表的人类活动影响的加剧，我国各大江河流域出口测站实测径流呈年总量减少、分配过程趋均化的演变趋势。复杂水库群工程体系调控极大程度改变了天然径流过程，导致水资源时空分布格局产生变化。项目以淮河水系鲁台子以上控制区域内20座大型水库构成的复杂系统为背景，就水库群工程体系调控对河川径流演变影响侦测、径流演变动力机制模拟、以及径流演变归因识别等方面展开研究。与现有研究成果相比，主要特色在于：①构建系统动力学模型模拟复杂水库群系统调控致径流演变机制，以耗散性用水量增长和水库群系统发展演化互馈关系为内在驱动，揭示径流演变物理成因。②发展复杂水库群工程调控下径流演变归因识别方法。以系统动力学模型为依托，采用输入—响应摄动分析对径流演变展开逐水库、逐要素归因，判别致径流演变的关键水库及要素，揭示水库间联合调控作用对径流演变影响。成果可为深入探索水资源系统演变机理提供理论支撑。

水库水利工程建设为代表的人类活动是影响河川径流演变的重要因素。围绕水库群工程体系调控致径流演变的影响影响侦测、径流演变动力机制模拟、以及径流演变归因识别问题，研究建立天然河川径流模拟的分布式SWAT模型，经基准时期与变化时期的径流模拟结果差异分析提取仅由水库群工程调节对径流演变造成的影响；结合考虑水库实时调度过程中预报不确定性及其影响，建立预报不确定性影响下的水库径流调节风险对冲模型并推导对冲解析规则，依据提取规则结合建立了复杂水库群调节对河川径流影响的系统动力学模型；采用参数摄动分析和归因辨识方法，定量评估水库群系统中各库对径流演变影响贡献占比及不确定性影响。对淮河干流鲁台子断面以上典型水库群系统进行分析，结果表明宿鸭湖水库调控对鲁台子断面径流过程影响最大，鲇鱼山、梅山水库次之，响洪甸、佛子岭水库对干流径流过程影响最小。成果可为深入探索水资源系统演变机理提供理论支撑。