嫩江下游土地沙化的时空变化——基于MODIS数据的遥感分析

Spatiotemporal change of desertification in lower reaches of Nenjiang River:a remote sensing analysis based on MODIS data

以2000,2004和2008年的MOD IS数据为主要数据源,以嫩江流域下游为研究对象,在Arc-G IS9.0和ERDAS IMAGE9.0等软件支持下,建立沙化模型,并对沙化进行了信息提取与分析;借助ArcG IS强大的空间分析功能,完成了土地沙漠化的定量分析及其时空变化规律,在此基础上进一步探讨了土地沙化的过程、机理和成因。结果表明:研究区域沙漠化土地以轻度和中度沙漠化土地为主;重度和极重度沙漠化土地的年增长率较大,水域的年减少率最大;重度、极重度沙漠化土地主要向较低等级的沙漠化土地和水域转变,呈现一定的逆转移。

Taking the MODIS data in the years 2000, 2004 and 2008 as data source and the lower reaches of Nenjiang River as research object the model was made and the information was extracted by using the software of ArcGIS 9.0 and ERDAS IMAGE9.0. Based on the powerful spatial analyst function of ArcGIS, the desertification of land in study area was quantitatively analyzed and the spatial-temporal changes regularity of desertification was studied. The procedure, mechanism and cause of desertification were explored, The results show that the light desertification land is the major portion of the desertification land in study area; the annual increasing rate of severe and very severe class of desertification land is larger, the annual decreasing rate of water region is largest ; the desertification land type is changed from severe and very severe class of desertification land to lower class of desertification land and to water region showing an inverse transformation.