基于网格单元的喀斯特石漠化评价研究

Assessment on Spatial Distribution of Karst Rocky Desertification at Different Grid Units

以盘县为例,综合遥感数据等多种数据源,在ARCGIS软件中应用格网分析技术,建立石漠化综合评价指数,对研究区2004年石漠化空间分布图进行100m×100m、200m×200m、500m×500m、1000m×1000m格网分析,绘制基于单元的石漠化分布图,以探索区域尺度上石漠化评价的方法及其随空间尺度的变化。建立石漠化综合指数,充分考虑一定空间单元内的石漠化面积比例和斑块组合,评价结果反映石漠化严重程度的空间异质性。结果发现基于4种网格的石漠化评价结果与石漠化现状分布图存在一定的差异,其中对极强度石漠化的评价差异最小,对轻度石漠化评价的差异最大。

Taking Panxian County as a study case,the authors make a thorough analysis on regional karst rocky desertification assessments and their spatial scale impacts based on different grid units at 100 m×100 m,200 m×200 m,500 m×500 m,1000 m×1000 m.The calculation of karst rocky desertification integrated assessment index （KDI） takes the percentage of areas and the patch assembles of grid units into consideration,which could reveals the spatial heterogeneity of karst rocky desertification.The results indicate that the KDI is influenced by assessment unit sizes,and there are some differences among assessment results of four spatial units and the actual distribution of karst rocky desertification.Moreover,the assessment results for karst rocky desertification at severe degree are consistent with the desertification distribution map,while those for the desertification at a light degree show a significant difference.