流域湿地的景观生态特性分析与景观特征指数的运用——以杭州沿山河流域和西溪湿地为对象

Analysis of landscape ecological features on watershed wetland and application of landscape characteristic index:illustrated with Yanshan River watershed and Xixi wetland in Hangzhou

以杭州市沿山河流域为例,应用景观生态学与碎片几何学的理论,采用景观特征指数的量化评价方法,分析了城市化对流域湿地原有景观地貌的干扰和破坏,以及水涝灾害发生的景观生态机理.城市化导致了系统形态结构的巨大改变,严重影响了流域的生物多样性、水文生态过程和视觉美学特质.景观结构的巨大改变引起了流域湿地贮、排水功能的衰退,主要表现为滞洪、消能空间的丧失,径流量的增加和汇水时间缩短等.探讨了量化分析景观特征、维护流域水文平衡的景观生态保护的新途径.

Illustrated with Yanshan River watershed in the city of Hangzhou, the disturbance and destruction of urbanization on the legacy landscape topographical features of watershed wetland were analyzed based on the theory of landscape ecology and fractal geometry and the quantitative assessment method of landscape characteristic indexes. The landscape ecological mechanism of urban waterlog was further studied. Urbanization causes great changes of shape and structure of the system and influences severely the biodiversity, hydro-ecosystem and visual esthetics characteristics. Large-scale changes of landscape structure cause the degradation of functions of storage and drainage in watershed wetland, which are reflected by loss of flood holding capacity, increase of surface runoff and decrease of confluence time etc. The quantitative analysis of landscape characteristics and the ways of landscape ecological conservation for maintaining the hydrologic balance of watershed wetland were discussed.