Using rs can rapidly finish the ecological investigation in different scales and analysis the ecological environment information in different period that it " s difficulty with general investigation , with its characters of multiplatform , multiband , multitemporal and its macroscopic and integrality . and when collecting , saving , drawing , changing , showing and analyzing the huge spatial data , the cis act the very important function as a very effective computer tool 遥感技术以其多平台、多波段、多时相宏观综合的特点，能便捷地完成常规方法很难实现的大、中尺度的生态调查研究和进行不同时期的生态环境信息的对比分析；地理信息系统作为一个极为有效的计算机工具，则在收集、存储、提取、转换、显示和分析这些容量庞大的空间数据时起到了非常重要的作用。
The steps of this change detection are : registering the multi - date image pairs , regularizing the image pairs , extracting the edges of the image pair , matching the edges of the edge - image pair , computing the edge difference image pair , marking the difference edges in the copies of the image pair 该变化检测法的工作流程为：多时相图像配准、图像标准化、提取参考图像及检测图像的边缘、匹配边缘图像中的边缘并获得边缘差分图像、标注变化情况。边缘检测算子的性能直接影响变化检测结果。
Duolun county , a typical farming - grazing transitional region located in inner mongolia , is chosen to be the typical research area and careful field investigation and spectral measurement were taken there . multi - temporal satellite imagery was selected on which integrated sandy land monitoring system was based . 1 本文选取位于农牧交错带内的内蒙古多伦县作为典型研究区，对该地区沙化土地类型进行了详细的地面调查和光谱测量，选用多时相landsat - 7etm +遥感数据，研究建立了一个完整的沙化土地监测系统。
