基于流域过程的淡水生态系统服务空间交互机制与水资源管理策略研究

气候变化与人类活动双重压力改变了流域生态过程，进而影响流域关键生态系统服务的提供。探究流域淡水生态系统服务的产生机制、流动过程与供需匹配关乎水资源的空间优化配置及其可持续利用，但目前相关研究仍显薄弱。本项目以涉及近千万人用水安全，深受自然和人类扰动的亚热带近海流域—九龙江流域为研究对象，基于生态系统服务视角，以流域过程—交互机制—管理策略为主线，采用定位观测、空间统计分析、流域模型模拟、社会—生态网络分析等耦合方法探究流域生态过程对九龙江流域淡水资源供给服务与水土保持、水质净化等调节服务的影响机制，识别不同类型生态系统服务的权衡、协同等空间关系并量化淡水生态系统服务的产生、传输路径和使用过程，阐释淡水生态系统服务的空间交互机制，藉此进一步提出基于生态系统服务的流域水资源管理新策略，为九龙江流域水源地保护、“河长制”的实施乃至九龙江-厦门湾的综合整治提供科学依据。

Managing watershed ecosystems to provide freshwater ecosystem services in the face of dual pressures from climate and land-use changes is a pressing challenge for science and policy. Freshwater resource management boundaries often mismatch with watershed ecosystem systems, which can lead to problems such as security of local/regional drinking water. As such, exploring spatial interactions among freshwater ecosystem services and thereby bringing the spatial optimization reallocation mechanisms into integrated water resource management is meaningful and practical. The Jiulong River Watershed (JRW), a subtropical coastal watershed in Southeast China that is experiencing coupled nature-human disturbances, is selected as a case study for its role in maintaining regional water safety. We propose a framework WPSISM ( Watershed Processes - Spatial Interactions - Systematic Management) for incorporating ecosystem services concept into integrated water resource management with the aid of in-situ observation, spatial statistics, watershed modeling and social-ecological network analysis. We first explore the influencing mechanisms of watershed ecological processes on the provision of freshwater ecosystem services and the underlying regulation services including soil-water retention and water quality purification. Then, we characterize the spatial interactions among the above-mentioned freshwater ecosystem services, such as trade-off and synergies, and further identify the source, pathway, sink and use regions to quantify freshwater ecosystem services flows. We finally develop an ecosystem services based water resource management strategies at landscape and watershed scales for sustainable utilization of water resource. We do hope this research could add values to science-based management and provide scientific support for Freshwater Reserves, River Chiefs and scheme of Comprehensive Improvements in the Jiulong River watershed–Xiamen Bay system.