Assessment Of The Ecological Environment In Tibet Based On GIS&RS

As the ecological protective screen of the southwest China and the highest platea of East Asia,Tibet breeds lots of famouse major rivers of the world.There is considerable climatic variation in Tibet,a part of the area is cold and dry throughout the year,at the same time the ecology is fragile.The special geographical location and unique topography make the ecological system of the Tibet region slightly changed,which is enough to pose a serious threat to the ecological security of surrounding countries and surrounding areas.In the few years,global warming has become more and more significant,and human social and economic activities have already been more and more frequent.Therefore,the environmental protection departments should approach the challenge such as the accelerated melting of glaciers and the deterioration of ecological environment.Based on the remote sensing satellite data,with the aid of the geographic information technology and the related statistical analysis method,we collect and process the satellite remote sensing images of Tibetan region during 2006-2016,in older to reflect the Tibetan areas,vegetation growth quality,plant productivity and regional ecological index of the heat and humidity.Based on the standardization of El and ecological index selection and approval of processing method of RSEI,the artical uses principal component analysis model,for ten years in Tibet region ecological environment quality evaluation analysis and dynamic monitoring.At the same time,according to the ecological environment comprehensive index,the artical studies the characteristics of spatial distribution and trend of ecological environment from time and space scale,combining with the natural factors such as altitude,slope,vegetation to analyse the result,exploring the main reasons for the Tibet regional environment change and provide some suggestions of environmental protection for goverment.The result of the research shows that:(1)The quality of ecological environment in Tibet is generally poor.In 2006 and 2016,the proportion of the ecological composite index was 72.44%and 70.74%.The regional difference was obvious,and the ecological distribution pattern of southeast and northwest was presented.The excellent ecological environment in the area are mainly distributed in the southeast of lower altitude valley plains,at the same time the fragile ecological environment in the area are mainly distributed in the central and northwest praromos region of Tibet,including the Gangdise Mountains,Northern Tibetan Plateau and so on,the reason of the distribution may be due to the hydrothermal conditions of imbalance which is caused by terrain;(2)The quality of ecological environment in Tibet has generally improved,and local areas tend to deteriorate.In terms of time series,the proportion of the regions with good ecological quality and variation between 2006 and 2016 was 18.09%and 8.02%respectively.In the spatial distribution,the area of ecological improvement is mainly distributed in the northwestern Tibetan plateau and the eastern hengduan area.The area of deterioration of the ecological environment is mainly distributed in the southeastern valley plain.The reason for this may be due to the northern and eastern region is located in the alpine plateau region,the global climate warming caused the region's natural environment improvement,southeast valley plains frequent economic activities,the development of the city led to the regional ecological quality to deteriorate;(3)The change of ecological environment quality in Tibet has a great correlation with elevation,slope and vegetation type distribution.Good regional ecological environment are mainly distributed in the eastern part of the low altitude,big slope forest and coniferous forest,ecological environment of poor areas are mainly distributed in northwest edge of high altitude and slope of small desert zone.Altitude,slope,the spatial distribution of vegetation types in a certain extent is verified in this paper,the ecological evaluation result accuracy,this paper demonstrates that the proposed ecological evaluation system suitable for Tibet area ecological environment research.