基于RS和GIS的南汀河流域石漠化评价

Rocky desertification evaluation based on RS and GIS in Nanting river basin

以南汀河流域ETM、DEM和地质岩性数据为基础数据,应用遥感和地理信息技术提取了石漠化评价因子,构建石漠化评价指标并对石漠化强度进行评价。运用空间叠加分析和统计分析方法对石漠化信息进行分析,得到流域岩溶区石漠化强度分级特征,利用土地利用数据及石漠化信息与土地利用/覆盖类型的相关关系以分析土地利用方式对石漠化的影响。结果表明(1)研究区石漠化强度为:中度石漠化>轻度石漠化>潜在石漠化>强度石漠化>无石漠化>极强度石漠化。(2)强度石漠化区和极强度石漠化区主要分布在以耕地和疏林地为主要覆盖类型的区域。说明了造成石漠化的因素除裸岩率、植被、坡度、岩性等主要影响因子外,人们利用土地的方式对石漠化也具有很大促进作用。

In this paper, remote sensing and geography information system technologies are applied on ETM, DEM and geological lithology data of nanting river basin to extract evaluation faetorsto create the evaluation index of rocky desertification, and to evaluate the intensity of rocky desertification. The intensity grading of rocky desertification in karst area was derived by using spatial overlay analysis and statistical analysis methods. The relationship between land use data and rocky desertification information and land use/land cover were used to analyze the impact of land use patterns on rocky desertification of Nanting river basin. The results indicated that, （1） the sorting of karst rocky desertification intensity by area is, medium〉light〉potential〉strong〉no rocky〉extremely strong rocky desertification. （2） The strong and extremely strong rocky desertification areas are mainly distributed in land cover types of cultivated land and sparse woodland. In addition to bare rock ratio, vegetation, slope, lithology and other main factors, land use by humanbeing also plays an important role in aggravating karst rocky desertification.