Abstract
Formosat-2 images, combining Digital Elevation Model (DEM) and GIS data, are used to analyze the change of land cover/use at Shui-Tian village. A group of Atayal people, called Shui-Tian tribe, live in an indigenous reservation of Hsichu County at medium elevations. A summer image and a winter image of Formosat-2 satellite for the year of 2006, 2008 and 2010 are selected for this study. The six images are normalized and converted into Normalized Difference Vegetation (NDVI) images. The NDVI difference images are generated by pairs of NDVI images. At first, the new bare lands are identified from the NDVI difference image with an optimal threshold. By overlaying the GIS land use/cover classification data, and fine-tuning the threshold, we can get a better identification of land-use change areas. Finally, the changes ranges are determined by combined 3D simulated images. In the preliminary results of study, Two bare lands could be identified from a summer and winter images in 2006. None can be identified to compare the summer images between 2006 and 2008. On the other hand, two new bare lands are identified to compare the winter images between 2006 and 2008. Two more new bare lands are identified to compare the summer images between 2008 and 2010. Another new bare land is identified to compare the winter images between 2008 and 2010. It is concluded that more new bare lands could be identified by using images pairs combining GIS and DEM data. The identified new bare area is helpful for Shui-Tian villagers to understand the status and developing history of the abused lands.