水电梯级开发对河流生态完整性的作用机理及生态调度模式研究

Due to massive cascading hydropower exploitation in watershed scale, the structural and functional degradation of riverine ecosystem, loss of biodiversity are the spotlights in riverine ecology studies. As a critical theory for riverine ecosystem protection in worldwide, the riverine ecological integrity is important to improve the understanding of cascading hydropower exploitation on riverine ecosystem. As the typical river basin for cascading hydropower exploitation in China, the middle and lower reaches of Lancang River basin is selected as research area in this research. On this basis, the riverine ecological integrity impacted by cascading hydropower exploitation, including physical, chemical and biological integrity, are developed on its theory and assessing method. In addition, the effects of cascading hydropower exploitation on mechanism of riverine ecological integrity are also detected in this research. In view of riverine ecological integrity protection, the ecological operation theory and model for cascading hydropower dams are preliminary established. This research results are not only make up insufficient mechanism and theory on riverine ecological integrity, improving ecological operation theory and model for cascading hydropower exploitation, but also can effectively achieve practices for transboundary river and aquatic ecosystem conservation, coordination of economic, social and ecological development.

流域大规模水电梯级开发所引起的河流生态系统结构和功能的退化、生物多样性的丧失是当今河流生态学领域研究关注的焦点。河流生态完整性理论作为当今国际河流生态系统保护的重要理论，对于完善水电梯级开发的生态影响认识具有重要意义。本研究以中国水电梯级开发的典型流域-澜沧江流域中下游为案例区，开展水电梯级开发对河流生态系统的物理完整性、化学完整性和生物完整性的评价理论和方法研究，探明水电梯级开发对河流生态完整性的影响和作用机理，并初步建立基于河流生态完整性保护的梯级水坝生态调度理论和模式。本研究的成果不仅可以弥补我国在河流生态完整性评价理论和作用机理方面研究的不足，进一步完善水电梯级开发的生态调度理论和模式，而且可以有效服务于我国跨界河流的水电梯级开发和河流的生态系统保护实践，实现流域经济、社会和生态的协调发展。

水电梯级开发虽然可以最大程度的利用河流的水能资源，但同时也是对河流生态系统的大规模扰动，对河流生态系统具有复杂和深远的影响。本项目选取中国西南生态脆弱区典型水电梯级开发的澜沧江中下游，以小湾、漫湾和大朝山梯级水坝库区为重点研究区，开展梯级水坝库区水生生态系统调查。项目研究基于河流生态系统完整性保护理论，围绕水电梯级开发对河流生态系统完整性的作用机理这一科学问题，结合澜沧江自然河流时期、单级水坝运行和梯级水坝运行等多期实地调查及文献资料，以大型底栖动物和沉积物为研究重点开展以下方面的研究：水电梯级开发条件下河流生态系统的响应及其动态演替；结合大型底栖动物群落结构、分布格局及沉积物重金属和营养盐的污染特征，阐明了水电梯级开发对河流生态系统完整性的作用机理；提出以河流生态系统完整性保护理论和近自然生境条件保护目标的梯级水坝运行及生态调度理论模式；探讨了澜沧江-湄公河水电梯级开发对国际航运通道建设以及“一带一路”倡议的影响。本项目的研究成果可以为水电梯级开发生态风险评估，河流生态系统健康评价，水生态系统的保护和管理提供科学的理论依据。