Research On The Dynamic Change Of Land Cover In Zoige County In The Past 50 Years

Land is an important place for human's survival and development,and also land is a basic place where human do all social and economic activities. But with the rapid development of society and economy,there are a series of environmental problems.It is a great challenge for human's life and nature,and also ecological environment has been severely damaged.As a result,the problem of land cover change has been noticed by scholars from all over the world.So the study of land cover change provides a scientific basis and theoretical support for the region ecological environment problems and sustainable development.According to GIS and remote sensing, the objective of this paper was to extract the information of land cover change in Zoige country and analysis of driving forces.Final,it takes some measures to protect the ecological environment.In this study, based on Multi – Source Remote images,the technology of combining of Object-Oriented and decision tree classification was presented to extract the land cover change information.When researched the comprehensive analysis of land cover change during 50 years,some mathematic models are used,such as land use dynamic degree madel and land use type transferring matrix model.In this study, the conclusions were drawn as follows:(1) By using decision tree classification,the land cover information of 2010 in Zoige was acquired.Then according to the overlay function of Arcgis,the land cover classification map about 1975?1990?1995?2000?2005 and 2015 was getted.(2)Based on the land cover classification map of 2010,the land cover change polygon was iterated.The interconversion of various types of land cover was acquired by land use type transferring matrix model.As a result,wetland has been declining,the area in 1975 was 2173.88km2,and in 2015,the area declined to 2055.48km2. and the area of grass was the biggest of all types of land cover.The increased area of forest was mainly transferred from shrub.The area of residential land and transportation was increasingall the time,the main contribution was grass.The desertification of grass was still expanding.(3)Analyzing the land dynamic change of Zoige by using the singular and synthetical land use dynamic degree model. Build-up land changed the biggest of all,and which is increasing all the time.Between 2005 and 2010,the singular land use dynamic degree becomed 4.703%;The change of wetland became obvious,but changed slightly.The result of synthetical land use dynamic degree was gradually increasing,which showed human activities are influencing more on it.(4)Analyzing the driving forces from qualitative and quantitative.The qualitative analysis mainly came from nature and human factors.Nature factors included temperature and rainfall.Human factors included drainage ditch and overgrazing. Combining social economic statistical data, The quantitative analysis mainly did principal component analysis.According to the first and the second principal component analysis,seven indicators were showed.The analysis showed that economic and population played the basic role in land cover change.(5)Aimed to the problems in land cover change and the influences to ecological environment,we needed combine the actual situation,put forward some measure to protecting and improving ecological environment.