Forest Lawn Dynamic Changes Based On "3s" Technology Research

3S"technology is the floorboard of Remote Sensing ,Geographic Information System and Global Positioning System. This technology is applied in many domains in social life, especially in the dynamic change of forest and grassland. The Three-Paralleled-River is in northwest Yunnan province. It has many characteristics such as high mountains and deep gorges paralleled, the obvious dieresis in vertical, the diversity of ecology, the plenty of biology, the frail ecology environment, kinds of national culture, the straggling economic etc.. The Three Rivers in this region is very important. They are all the upper river of great river., through researching this region, we can firstly ravel the change of forest and grassland in this region ,which has frail ecology; secondly we can advise the compulsive development of great river. This research is put up in technology, mainly use remote sensing as instrument, and landscape ecology as technique. Firstly, we use "3S"technology to analysis the satellite抯 photo ,gain the cover map of forest and grassland in 90 and 99. Secondly as congruence the two maps, we gain the database of the dynamic change of forest and grassland. Thirdly we use the method of landscape ecology to analysis these changes, the mechanic of changes ,the impactions ,and the mode of using and managing forest and grassland. The change of forest and grassland in this region is obvious. Firstly, natural plants has gradually changed to man made plants; secondly the tilth has increased, thirdly the biggest change is through highways and residents; fourth, the change in low elevation is higher than in high elevation. By summarizing these changes and integrating the characteristic of this region , we gain the use mode of the forest and the grassland in the future in this region: In the valley(the elevation is lower than 2000 meters), this is the mainly life region . in this region we should control the development of the population , and increase the devotion of science and technology also we should improve the efficiency of land use. In the middle mountain(the elevation is higher than 2000 and lower than 2600 meters). In this region we should decrease the function of production, and make it turn to ecology building. In the high mountain(the elevation is higher than 2600 meters).in this region we should keep the function of ecology, and stop the excessive herd and slash. We mainly use ?S-echnology in this research . But because of the variety of elevation , shadow areas in this satellite photo are very large. To solve this problem we made some new ways, firstly we use GPS points to partition the sample area. It help us increase the precision of the supervised classification. Secondly we convert the classification map which is raster data into vector data ,meanwhile we use many kinds of vector model to check the precision of classification map, such as equal elevation line , DEM model , river system map, land use map etc.. Through these method we also improved the precision highly in shadow parts. In the future ,we may also use many even new methods in this kind of research. such as use GIS to set up Experts Analysis System, through this way we can save many times ,and decrease the disturb by man in interpreting satellite photo.