渭河流域河流栖息地完整性与生态基流响应机制研究

There has been increasing environmental flow requirements shortage due to intensive water resources development, which has led to remarkable habitat degradation in the semiarid Wei River Basin. Therefore, ecological risk level of the basin is increasing and the natural ecological function of the river ecosystem is incomplete. Environmental flow requirements calculation and assessment based on the response mechanism of river habitat integrity and environmental flow requirements has become the manager's bases for decision making. In the project, river habitat integrity conceptual model, assessment method and the corresponding assessment indicator system at river system scale and river reach scale will be proposed by analyzation of composition components and stress factors for river habitat integrity of the Wei River Basin. River habitat integrity of typical river systems and river reach will be assessed based on field investigation, regression analysis and improved gray incidence analysis. As well as, ecological risk level at basin, river system and sub-ecosystem scale will be analyzed, and the response mechanism of river habitat integrity and environmental flow requirements will also be proposed. Furthermore, environmental flow requirements calculation model for river habitat integrity restoration, which aim to optimize improvement of river ecological risk and river ecosystem function, and ecological risk level under different water division scenarios of the basin will be proposed finally. The research results can provide scientific basis for water resources management and ecological restoration at present, after completion of the Hanjiang-to-Weihe River Water Transfers Project and the West Line of South-to-North Water Diversion Project in the Wei River Basin.

处于干旱半干旱区的渭河流域，高强度的水资源开发利用过多占用了河流的生态基流，导致河流生态功能不完整甚至缺失、流域生态风险加剧、不同尺度下河流栖息地完整性受到强烈人为干扰。基于栖息地完整性与生态基流响应机制的生态基流计算和评估成为流域管理者决策的重要依据。本项目通过辨析渭河流域河流栖息地完整性构成要素及胁迫因子，拟构建河流栖息地完整性理论框架、河流栖息地完整性评价方法及评价指标体系，应用现场调查、回归分析和优化的灰关联度分析法，对水系和河段尺度下河流栖息地完整性进行评价，一方面辨析流域、水系和子生态系统尺度下河流生态风险分异特征，并揭示河流栖息地完整性与生态基流响应机制；一方面以流域生态风险控制和河流生态功能改善为目标，构建栖息地完整性恢复的生态基流计算模型，探寻不同来水情景下流域生态风险水平，为现阶段、引汉济渭和南水北调西线等重大调水工程实施后，流域水资源管理和水生态恢复提供科学依据。

处于干旱半干旱区的渭河流域，高强度的水资源开发利用过多占用了河流的生态基流，导致河流生态功能不完整甚至缺失、流域生态风险加剧、不同尺度下河流栖息地完整性受到强烈人为干扰。基于栖息地完整性与生态基流响应机制的生态基流计算和评估成为流域管理者决策的重要依据。本项目通过辨析渭河流域河流栖息地完整性构成要素及胁迫因子，构建河流栖息地完整性理论框架、河流栖息地完整性评价方法及评价指标体系，应用现场调查、回归分析和优化的灰关联度分析法，对水系和河段尺度下河流栖息地完整性进行评价，一方面辨析流域、水系和子生态系统尺度下河流生态风险分异特征，并揭示河流栖息地完整性与生态基流响应机制；一方面以流域生态风险控制和河流生态功能改善为目标，构建栖息地完整性恢复的生态基流计算模型，计算渭河、泾河及北洛河水系22个断面的月生态基流，分析水系及河段尺度生态基流的时空分异特征，并探寻了不同情景下流域生态风险水平，研究结论可为流域水资源管理和水生态恢复提供科学依据。