毛乌素沙地沙漠化的遥感监测

通过对１９８７年和１９９３年ＴＭ数据的分析和计算机辅助系统的应用，开展了毛乌素沙地沙漠化土地的动态监测。结果表明，在这７ａ间，研究区内沙漠化土地面积共减少了１９３６ｋｍ２，总体上处于稳定的逆转状态，但局部地带沙漠化迅速蔓延不可忽视；几乎所有的逆转面积都来自于被固定和半固定后的流动沙丘（地）面积的减少，可见“三北”防护林建设及沙地围封保护的积极效果；但作为农牧业用地的不同程度沙漠化土地逆转不明显，势必会影响到防治的经济效益。研究还表明，遥感与计算机相结合对沙漠化土地的监测评价是一种行之有效的定量研究方法

APPLING REMOTE SENSING DATA FOR DESERTIFICATION MONITORING IN THE MU US SANDY LAND

Based on the analysis of the Landsat TM data (April 1987 and April 1993) and application of computer, we have carried out a project on the trends monitoring of desertified land in the Mu Us Sandy Land. The results indicate that the desertified land had decreased about 1 936 km 2 from 1987 to 1993 and kept a stable reversed situation in the overall statue, although there were some parts of the area had been suffered from a quick spread of desertification. Almost all of the reversed land come from those areas where the shifting dunes have been fixed by reforestation and fencing for vegetation protecting. But the reversed trend was not so clear to those desertified land which was used for cropping and grazing, so that the economic benefit of combating desertification was not so encouragement. By this project, we believe that to make full use of the remote sensing data for monitoring and assessing the desertification is one of the effective measure of quantitative research.