城市化对河流生态系统综合影响评估及机制研究——以苏州为例

Urbanization sets into motion a cascade of change to natural streams. These changes, collectively termed the urban stream syndrome, have been the subject of an expanding field of Geography, Environment and Landscape Ecology. But many questions about identification, evaluation and the mechanisms driving the urban stream syndrome and the response of urban stream ecosystem to its disturbance remain unanswered. Identification of key questions is an important step toward effective, efficient management of urban streams to meet ecological civilization goal. This study intends to take Suzhou city which located in the abdominal region of Taihu lake watershed as the study area. Based on remote sensing data and the field monitoring data, the urbanization evolution process is analyzed and concept model of urban stream syndrome is set up. The index system, including morphology, hydrodynamics, water quality and zoology is established, and the fitting assessment model is put forward to quantitatively evaluate the urban stream syndrome. Based on the Benthic-Index of Biotic Integrity (B-IBI), the Hierarchy structural model which including land use, hydromorphology and physic-chemistry in the watershed, riparian corridor and hydromorphological reach is established. With the use of structural equation model (SEM), the influence of each stressor on urban stream system and interactions among them is explored. The key stressor that affect the urban stream system is identified. This study can provide a theoretical basis for the ecological restoration and management of urban streams and optimization of landscape pattern.

城市化作用下自然河流呈现的“城市河流综合症”是地理、环境与景观生态学交叉研究的热点问题，但关于城市河流综合症识别和量化评估、驱动机制及河流生态系统对其扰动的响应机制仍有许多问题尚未解答。确定这些关键问题是实现城市河流有效管理以实现生态文明目标的重要一步。本研究拟以太湖流域腹地苏州为研究区，利用遥感数据和野外监测数据，分析城市化演化过程，构建研究区城市河流综合症概念模型，从水质、水生态、河流水文和河流形态等四个方面建立评价体系，构建城市河流综合评价模型，定量评估城市河流综合症。同时以底栖动物完整性指数为水生态指标，建立土地利用、河流水文形态和水体物理化学因子在流域、河岸缓冲区和河段等空间尺度的层级结构模型，利用结构方程模型，探讨各驱动因子对河流生态系统的影响并分析各因子之间的相互关系，识别影响城市河流生态系统的关键因子，研究可为城市河流生态修复、管理和城市土地利用景观优化提供理论依据。

城市化作用下自然河流呈现的“城市河流综合症”是地理、环境与景观生态学交叉研究的热点问题，但关于城市河流综合症识别和量化评估、驱动机制及河流生态系统对其扰动的响应机制仍有许多问题尚未解答。确定这些关键问题是实现城市河流有效管理以实现生态文明目标的重要一步。.本项目以苏州市为研究区，利用长时间序列水质数据和水生态数据，构建了城市河流水环境评价模型，分析了苏州城市河流水环境时空分布特征。基于长时间序列土地利用数据，应用ArcGIS空间分析技术，结合土地利用景观格局指数，研究了苏州近40年土地利用及景观格局演变特征。依据城市扩展动态的研究理论与方法，分析了苏州城市建设用地演变过程、格局和驱动机制，计算了表征城市形态的分形维数、紧凑度指数，识别了苏州城市建设用地的扩展类型并分析了影响建设用地扩展的主要因素。基于不同时期城市土地利用景观特征和水环境指标数据，分析了景观格局与水质响应关系的多尺度效应，探讨影响城市河流水环境的主要因子。相关研究可为苏州城市河流水环境提升和保护以及太湖流域城市空间开发提供参考决策。.本项目发表论文5篇，其中EI1篇，国内核心期刊论文3篇，申请软件著作权1项，对人才培养、团队建设等起到良好支撑。