基于景观“源－流－汇”耦合模拟的流域水环境安全格局优化——以太湖上游水源区苕溪流域为例

随着点源污染的有效控制，非点源污染已成为当前中国水环境的最大威胁。景观格局演变作为人类活动的综合表征，对流域水环境产生深刻影响。但由于高强度人类活动作用下景观格局的高度空间异质性，使得景观格局和水环境的关系复杂多变，如何通过优化景观格局实现非点源污染的科学有效减排，目前尚缺乏成熟的模式和方法。本项目从景观生态学的角度，将水域过程融入陆域格局，通过样点微观过程与流域空间格局、地面监测与空间遥感、定点观测和模型模拟的结合，分别在缓冲区、子流域和流域3个尺度上，实现景观“源－流－汇”格局与水环境过程的时空耦合模拟，揭示不同尺度上流域景观格局对水环境的影响机理，优化构建流域水环境安全格局，为流域非点源污染的有效控制提供新的视角和思路。该研究不仅在实践上可从景观整体视角为非点源污染的有效防治提供科学指导，而且在学科上可丰富“格局－过程－尺度”的定量耦合理论。

With the effective control of point source pollution, non-point source pollution has become the biggest threat to water environment in China. As a comprehensive representation of human activities, landscape pattern dynamics has a profound impact on the water environment of the watershed. However, due to the high spatial heterogeneity of landscape pattern under the high-intensity human activities, the relationship between landscape pattern and water environment is complex and indefinable. How to reduce the loads of non-point source pollution by optimizing the landscape pattern is still lack of effective models and methods. From the perspective of landscape ecology, this project integrates the water process into the landscape pattern. Through the combination of micro-process of sample plot and spatial pattern of watershed, ground monitoring and spatial remote sensing, field observation and model simulation, the "source-flow-sink" landscape pattern and water environment process is coupled spatiotemporally on the scales of buffer zone, subwatershed and watershed, respectively. By revealing the impact mechanism of landscape pattern on water environment on different scales, the water environment security pattern of the watershed is optimized. This project provides a new perspective and idea for the effective control of non-point source pollution in the watershed. This result will not only provide scientific basis for the effective control of non-point source pollution in practice, but also enrich the "pattern, process, scale" coupling theory.