一维二维耦合模型研究水库运行对下游河道水环境的影响

水库运行造成的河道水流条件的改变给下游的水生态系统带来重要影响。耦合水动力过程及生态过程的生态水力学模型可以有效地定量评价这种影响。本研究以广西漓江为实例，建立了全河流一维和局部河段二维水环境模型。其中的一维模型分析全河段水环境变化趋势，二维模型分析关键区间水环境的特点，并为后续的生物栖息地模型奠定基础。模型分析了典型水文年中自然径流和青狮潭水库运行两种模式下下游河道关键水环境因子的变化。模拟结果表明水库运行在平水年的影响大于丰水年和枯水年，局部浅水区的变化大于深水区，年内枯水期(10-12月)的影响大于年均值，而且这些变化沿程逐渐减弱。该研究成果为下一步的生态模型提供了外部因子。

Study on the Environmental Flow Changes due to Upstream Reservoir Operations through an integrated 1D2D Model

the modification of flows due to river regulations has great impact on the downstream aquatic ecosystem. It is important to quantitatively evaluate these effects, and ecohydraulics models that integrates hydrodynamics processes and ecological processes are prove efficient methods to achieve the objective. This research took the Lijiang River as the case and developed an integrated 1D2D model. The 1D module simulated the entire river, and the 2D module simulated the typical river sections so that provided the external forcings to the forthcoming habitat module. The model analyzed the flow and water quality changes in the downstream under natural runoff and Qingshitan Reservoir operations. The results indicated that the effects of the reservoir operations decreased from upstream to downstream. They were more significant in even flow year than in dry and wet year, more serious in shallow area than in deep area. Within the year, they were more obvious in dry season than the average. The research presented in the paper provided the basis for the ongoing development of the ecological module.