近10a广西喀斯特地区石漠化景观格局分析

广西壮族自治区是中国亚热带喀斯特典型地区,石漠化情况严重。以SPOT-VEGETATION影像为主要数据源,运用MVC方法和像元二分模型,结合地质、地貌和土地利用现状图,反演了1998,2003,2007年广西喀斯特地区的石漠化分布,在FRAGSTATS平台下,选取香农多样性指数(SHDI)、蔓延度指数(CONTAG)等景观格局指标,运用景观空间分析方法对广西喀斯特石漠化近10a空间格局演化特征进行了分析。研究结果表明,区域石漠化景观水平整体异质性低,内部混合度大。石漠化治理效果明显,各类石漠化面积共减小177 283hm2,其中轻度石漠化变化最大,是治理的首要和重要目标。

Landscape Patterns of Rocky Desertification Land in Karst Region of Guangxi Zhuang Autonomous Region in Recent 10 Years

Guangxi Zhuang Autonomous Region is a typical subtropical karst region with severe rocky desertification in China.Based on the SPOT-VEGETATION images used as the main data source,the distribution of rocky desertification in Guangxi Province in 1998,2003,and 2007 is inversed by combining maximum value composites(MVC) method and dimidiate pixel model with geology,landform,and landuse map.Additionally,in FRAGSTATS platform,the evolutionary characteristics of rocky desertification in the 10 years are analyzed by selecting some landscape pattern indexes,such as Shannon Diversity Index(SHDI) and Contagion(CONTAG),and using spatial analysis method of landscape.Results from the research show that the overall landscape level of rocky desertification in the region was characterized by high inner homogeneity and low landscape heterogeneity.The total rocky desertification area decreased by 177 283 hm2,indicating a good effect of management.The change in light rocky desertification was most significant and the area for this type of rocky desertification is the important and prime objective of management.