基于RS和GIS的石羊河流域生态环境质量空间分布特征及其影响因素

基于RS和GIS技术方法,选取自然资本、社会压力和经济支撑3方面的11个指标,利用空间主成分分析法、变异系数法和层次分析法,构建自然资本指数(NCI)、社会压力指数(SPI)、经济支撑指数(ESI)以及生态环境质量评价指数(EQEI),对石羊河流域生态环境质量空间分布特征及影响因素进行分析.结果表明: 石羊河流域生态环境质量整体处于较差水平,生态环境质量等级为优、良的区域主要集中在流域上游的祁连山地区,等级为较差及其以下的区域主要集中在中、下游的低山丘陵区和荒漠区.石羊河流域EQEI值在西南-东北方向上具有两极分化现象,随着距离变化,该值变化幅度较大,存在明显的空间异质性.石羊河流域生态环境质量以高-低值两种聚集模式共存,主要呈现“断裂式”分布,并具备热点高度聚集、冷点高度聚集的特征.在石羊河流域生态环境质量的影响因素中,自然资本因素占据主导地位,社会压力因素次之,经济支撑因素的影响最小.

Spatial distribution characteristics and influencing factors of eco-environmental quality based on RS and GIS in Shiyang River Basin,China.

Based on RS and GIS, 11 indexes from three aspects including natural capital, social pressure and economic supports were selected. The natural capital index (NCI), social pressure index (SPI), economic support index (ESI), and environment quality evaluation index (EQEI) were constructed by using spatial principal component analysis, variation coefficient method, and analytic hierarchy process. The spatial distribution characteristics and influencing factor of the environmental quality in Shiyang River Basin were analyzed. The results showed that the overall environmental quality was at poor level in Shiyang River Basin. The regions with better classes of environmental quality were mainly concentrated in the upper reaches of Qilian Mountains, and those with poorer classes were mainly concentrated in the middle-lower reaches of low hills land and desert. The EQEI value in Shiyang River Basin had polarization phenomenon from southwest to northeast. With the variation of distance, the value had large variation range, with obvious spatial heterogeneity. The environmental quality showed both high and low aggregation patterns, with "fault" distribution. There were highly clustered hot spots and highly clustered cold spots in the basin. Among the influen-cing factors of environmental quality, natural capital was the dominant one, social pressure was the second, and economic support was the least contributor.