基于景观结构的渭河下游河流沿线区域生态风险分析

Ecological Risk Analysis Based on Landscape Structure in Catchment Area along the Weihe River

根据区域景观生态风险分析的方法和步骤,以渭河下游河流沿线区域为研究区,利用GIS和数学建模方法,在对1990和2002年两个时期的遥感影像进行景观分类后,以7种景观类型所代表的生态系统为风险受体,通过构建生态风险指数模型,划分风险小区,利用地统计学中的空间分析方法,首先获得了1990和2002年以人类干扰为风险源的生态风险指数空间分布图。然后通过对这两期生态风险指数空间分布图进行5个级别的风险区划后,不仅对两个时期生态风险的空间分布特征进行了分析,而且对这13年间各级别风险区的空间转换进行了探讨。其结果可为生态环境建设和风险管理提供数量化的决策依据和理论支持。

According to the methods and steps of regional landscape ecological risk analysis, taking the catchment area along the Weihe River as a study area, by using GIS and mathematical models and methods, after classified two remote sensing images in 1990 and 2002, taking seven types of landscape as risk receptors and human interferences as risk sources, through constructing index＇ s model of ecological risk and dividing risk sections, using spatial analytic methods of geographical statistics, two spatial distributing images about ecological risk index were firstly acquired. After divided two spatial distributing images about ecological risk index into five grades, this paper not only analyzed spatial distributing characteristics of ecological risk on the two periods, but discussed spatial transformation to risk zones of every grade in thirteen years. The results can provide quantitative decision-making basis and theoretic support for ecological environmental construction and risk management.