典型喀斯特山地城市不透水面时空格局

Spatial and Temporal Pattern of Impervious Surface in Typical Mountainous Cities of Karst

以贵阳市主城区为研究区,利用基于植被覆盖度提取法和线性光谱混合分析法分别提取研究区不透水面信息;通过精度对比,选用最优方法提取研究区1996、2007、2017年的不透水面信息,并结合标准差椭圆法和相关扩展指标探讨不透水面的时空演变。结果表明:在喀斯特地区利用线性光谱混合分析法提取不透水面信息效果较好;1996—2017年间研究区不透水面的空间分布趋势经历了从西南—东北分布变化为正北—正南分布,再变化为西南—东北分布的过程;不透水面扩展模式前期主要以单级为核心向四周发散,随时间推移转变为多中心扩展,并伴随大量“飞地”的出现。

Taking the main urban area of Guiyang city as the study area,the extracting method based on fractional vegetation coverage and the linear spectral mixture analysis method were used to respectively extract the impervious surface information in the study area.After the precision comparison,the optimal method was selected to extract the impervious surface information of the area in 1996,2007,and 2017.The spatial and temporal evolution of the impervious surface was discussed by combining the standard deviation ellipse method and the correlation extension indexes.The results show that the effect of extracting impervious surface information by using the method of linear spectral mixture analysis in karst area is better.The spatial distribution trend of the impervious surface in the study area from 1996 to 2017 undergoes a process from southwest-northeast distribution to north-south distributionand then to southwest-northeast distribution.In the early stage of impenetrable water surface expansion mode,it mainly diverges in all directions with a single stage as the core.With the passage of time,it becomes a multi-center expansion,accompanied by the emergence of a large number of“enclaves”.