Dynamic Monitoring Of Ruoergai Plateau Wetland And Its Driving Force Analysis Based On RS, GIS And GPS Techniques

Ruoergai wetland is not only the largest plateau swamps in our nation, but alsothe largest and best preserved plateau peat swamp in the world. It is located in theeastern margin of Qinghai-Tibet Plateau, as the most important headwater of YangtzeRiver and Yellow River; it is renowned as "the national water tower" in Chinesescientific community. Meanwhile Ruoergai wetland is also a typical representative ofthe Qinghai-Tibet Plateau alpine wetland ecosystem. However Ruoergai wetlandecosystem is very frail, especially because of the dual effects by natural factors suchas the global warming, rodents and pests'problem, and human factors such as marshdrainage, overload grazing in recent years, the problem of Ruoergai wetland'sdecrease is increasingly obvious. Therefore, it is of great significance to protectRuoergai wetland and realize sustainable use of regional resources by dynamicmonitoring method.In this paper, the TM images of 1990, 2000 and 2009 are used as the main datasources, while administrative zoning, topographic maps, meteorological data, relatednatural economic yearbook and GPS data come from investigation are supplement.Based on 3S technology, i.e. remote sensing (RS) and geographic information system(GIS) and global positioning system (GPS) technology, with the help of time seriesmethods and landscape pattern analysis, this paper detects the dynamic changepatterns of Ruoergai wetland over the past 20 years. According to the analysis result,the driving force of the wetland shrinking from natural factors and human factors aredescribed and how to protect the environments are put forward at last.(1) On the foundation of the original wetland classification system, this thesismerged some wetland class properly and established the wetland classification systemwhich is more suitable for wetland information extraction, classification and analysiswith the reference of its own characteristics of Ruoergai County.(2) With the help of multi-temporal remote sensing data, Ruoergai County isselected as the key research area. The sensing interpretations features of wetland arebuilt through the comprehensive analysis refer to the indoor interpretation training andGPS field validation, and then the wetland information is extracted by visualinterpretation with interpretation accuracy ensured.(3) Supported by the spatial analysis function of GIS, the dynamic change patterns during the past 20 years is described from the four aspects range fromwetland quantity change, wetland spatial distribution change, wetland dynamictransformation to wetland landscape pattern changes, meantime, the analysis of thedriving forces of wetland shrinking is supported by effective data.(4) Based on the meteorological data and field survey data, the reason of wetlandshrinking from the four nature factors of rising temperatures, reducing rainfall,increasing evaporation and rodents and pests problems are analyzed and the drivingforces range from human factors including over-grazing, peat mining and marshdrainage are described. Finally, according to t analysis results, some measures toprotect the wetland are put forward.