利用探索性空间数据分析以及百分位数和变异系数,基于ArcGIS和GeoDA软件支撑。对洞庭湖区生态承载力的空间格局特征、空间关联特征和相对差异演变特征进行分析。结果表明:①空间格局上,洞庭湖区生态承载力从西南向东北大体上呈现“w”型(较高-低-高-低-较高)空间格局,倒“u”型的县域差异特征显著。②空间关联上,洞庭湖区生态承载力的分布呈正的全局空间自相关,出现相似县域之间的空间集聚,全局Moran’SI值相差不大,空间聚集程度比较稳定,趋于围绕某一偏低集聚度出现小范围内波动;局部空间自相关的LISA集聚类型出现HH型、HL型和LH型3种类型,依次集中分布在洞庭湖区的中部、西南部和东北部,局部空间格局保持相对稳定,但是聚类特征显现出稍微变化的迹象。③相对差异演变上,2001-2010年洞庭湖区生态承载力相对差异演变整体上呈现一定的差异性。2001-2003年相对差异较小,趋于稳定;2005年前后相对差异较大;相比2001-2003年,2005年以来相对差异明显扩大且这种较大的空间相对差异随着时间的推移呈现小幅波动趋势。
With the support of Arc GIS and Geo Da software and using exploratory spatial data analysis as well as percentile and coefficient of variation, this paper analyzes the spatial pattern and the evolution of the spatial autocorrelation characteristics and relative difference characteristics of ecological carrying capacity in the Dongting Lake region from 2001 to 2010. The results show that: (1) As a whole, the spatial distribution of ecological carrying capacity presents a W-shaped pattern from southwest to northeast and the difference of an inverted-U shape between counties are apparent. (2) As to spatial autocorrelation, the distribution of the ecological carrying capacity of global spatial autocorrelation is positive. There is spatial gathering between similar counties; Global Moran's I is almost the same in different counties; the degree of spatial aggregation is relatively stable and fluctuates around a low degree of aggregation within small scale; LISA cluster of local spatial autocorrelation can be divided into three types, including HH, HL and LH, which are in turn concentrated in the central, southwest and northeast parts of the Dongting Lake region; local spatial pattern remains relatively stable, but the clustering characteristics shows a sign of slight change. (3) As to the evolutionary process of relative differences, the ecological carrying capacity of the Dongting Lake region shows some differences from 2001 to 2010 as a whole. The relative difference is small from 2001 to 2003 and tends to be stable; there is relatively large difference before and after 2005; the relative difference since 2005 has become greater.