大型水利水电工程生态环境效应水动力学机理及调控

For quite a long time, hydropower development in our country has been mainly oriented to flood control, power generation and navigation, while rarely considered the environment, drought resistant and water replenishment. Lack of fundamental research on ecological and environmental effects of large hydroelectric projects has become the bottleneck and will affect the future of hydropower development. Hydropower development of the impact on the environment has been concerned for a long time in abroad, but its management concepts are often limited in some specific water areas and functions, which have little adoptability for projects in our country. The continuous and serious drought appeared at the mid and lower reaches of the Yangtze River in 2011. Through the regulation of the Three Gorges Project, the water resources of such areas were timely replenished; though the emergency replenishment appeared to be beneficial, but there is a lack of scientific basis and principle during the operation. Aiming at the typical problems of algal blooms in reservoir tributary bays, impaired habitats of aquatic animals, and degraded water environment of river-connected lakes after the construction of major water conservancy project, this study attempts to: using the field monitoring and modeling methods, analyze the similarities and differences and their possible relation, establish the theory of ecological operation for the large hydroelectric projects, and then present the systematic method and key technology. The research is a hot issue in hydropower development and a key technology that restricts the development the large hydroelectric projects, which has important significance in the theory and practice for construction, operation management, and protection of ecology and environment.

长期以来我国水电开发以面向防洪、发电、航运等功能为主，对生态环境和抗旱补水考虑的不多。对水利工程生态环境效应和基础研究缺少研究，成为未来水电事业发展的瓶颈。国外水电开发对水域生态环境问题关注较早，但其管理理念往往只局限在特定水域和功能上，对我国的实际工程可借鉴性差。2011年长江中下游地区出现了持续严重干旱，通过三峡水库拦蓄洪水以及及时向中下游补水等措施，对应急补水调度进行了有益的尝试，但是缺少调控的科学依据和原则。本项目以重大水利工程为依托，针对水利水电工程建设和运行过程中出现的库区支流水华、重要水生物生境胁迫、江湖关系等涉及的水动力学基础及调控问题，采用现场观测和数值模拟相结合的方法，建立大型水利水电工程生态调度的理论，提出系统的方法和关键技术。该研究是当前水利学科中的热点问题和制约水利水电开发的关键科学问题，对水利水电工程建设、运行管理和生态环境保护具有极其重要的理论意义和实用价值。

水利水电工程在发挥防洪、发电、航运等综合效益的同时，也不可避免改变上下游河道水动力条件，进而影响河道生态环境。然而目前对水利工程生态环境效应和基础研究缺少研究，成为水电事业发展的瓶颈。国外水电开发对水域生态环境问题关注较早，但其管理理念往往只局限在特定水域和功能上，对我国的实际工程可借鉴性差。通过三峡水库拦蓄洪水以及向中下游补水等措施，对应急补水调度进行了有益的尝试，但是缺少调控的科学依据和原则。本项目以三峡等重大水利工程为依托，重点开展了以下三个方面的研究：大型水利水电工程对敏感水域水动力条件的影响、水动力条件变化对敏感水域典型生态环境问题的作用机制、大型水利水电工程多目标优化生态调度的水动力调控原理。通过该课题的研究，系统分析了三峡水库运行前后敏感水域水动力变化特征及关联性，提出了水动力条件变化对库区支流富营养化、坝下河道重要水生物资源、中游江湖关系及通江湖泊水环境的影响规律及调控方案。研究成果如下：（1）针对水利工程影响下河道型水库支流库湾富营养化及水华问题，建立香溪河局部富营养化三维模型，阐明了藻类和主要污染物迁移转化规律；（2）针对水利水电工程建设与运行对重要水生生物生境胁迫问题，研究产卵场生境安全的水动力评价体系，建立了中华鲟产卵场适合度模型；（3）针对水利水电工程影响下江湖关系及通江湖泊生态环境问题，基于构建的长江中游江湖一体化耦合水动力模型，分析了三峡水库运行对通江湖后水情的影响机理；（4）阐明了大型水利水电工程多目标生态调度的水动力调控原理并提出针对上述问题的具体的方案。该研究是当前水利学科中的热点问题和制约水利水电开发的关键科学问，将加深对大型水电工程生态环境效应的客观认识，对有序开发水电资源具有重要的理论意义和应用价值。