不同时相遥感图像光机复合处理提取土地荒漠化信息研究

EXTRACTION OF THE CHANGE INFORMATION OF LAND DESERTIFICATION FROM MULTITEMPORAL REMOTE SENSING IMAGES BY THE METHOD OF COMBINING OPTICAL FALSE COLOUR COMPOSITE WITH COMPUTER DIGITAL IMAGE PROCESSING

光机复合处理技术大大简化了常规遥感制图方法的繁琐步骤．它利用不同时相的遥感图像提取出土地荒漠化变化信息，不仅能确定出土地是否发生了荒漠化以及荒漠化的强弱程度，而且还能将已荒漠化的土地按荒漠化变化程度区分为5种荒漠化无变化型、3种荒漠化增强型和4种荒漠化减弱型．所生成图像上反映出的自然景观带不仅与实地情况完全一致，而且带界精度都能保证在一个像元之内．

This paper discusses the method and its effect of the extraction of change information of land desertification by the approach combining optical colour compsite with computer forage processing. In the way proposed in the paper, not only the non-desertilied land can be distingUished from the desertified land, but also the information of desertification degree can be got from the different temporal remote sensing data. According to the degree of desertification, the desertified land is divided into five unchanged types, three intensified types and four alleviated types. The field work precision check indicates that the result of the research is satisfactory. The landscape zones which are shown in the produced composite images correspond to the situation of fleld work very well. The error of demarcation line between the different sketch patterns is less than a pixel.This method can simplify the traditional remote sensing cartographic course, increase the accuracy of cartography, and driprove the approach in the study of land desertification change.