Study On The Temporal And Spatial Distribution Of Vegetation And Its Impact Factors Based On RS In Beijing

Population growth and Social and economic development put a lot of pressure on municipal ecological environment. Beijing had experienced a rapid development in the past few years and environmental problems has become a urgent problem in the process of development. It is very important for us to assess the mechanism and variation law of ecological environment and its impact factors from regional scale, which will help to take protective measures. Vegetation play a key role in the process of hydrology because it change with the climate, land feature and human activity. The thesis studied the distribution of vegetation and its impact factors based on RS in Beijing, which has an important practical significance.On the basis of reviewing abundant overseas and civil literatures about this topic, the thesis concluded the application of RS in the ecological environmental assessment area and developed a route which uses NDVI as an index of vegetation. The thesis collect many atmosphere, land feature and RS data which be dealt with ENVI and ARCGIS software and then find out the spatial and temporal distribution and its variation laws, along with its impact factors, some conclusions were drew below:There are similar variation laws in different land use category with some differences, NDVI of city and towns arrived at the highest level in July, whereas arable land and nature vegetation are at August. The rate of growth and recession of nature vegetation is faster than arable land, which is faster than city and town areas. From 2000 to 2009, the vegetation degeneration areas are mostly located in southern east of Beijing, but vegetation in the northern west of Beijing primarily remains stable. The suburb in Beijing showed a better vegetation condition. Districts in Beijing showed little fluctuation in NDVI value, but almost stay still in the past ten years. Mountainous areas in Beijing where altitude is higher than 200 meters experienced a highly positive correlation between the NDVI and altitude. NDVI in shade slope is higher than sunny slope. There is a highly positive correlation between the rainfall in summer and vegetation index, but it has a lagging effect. It has no clear correlation among NDVI in city and town or arable land, yet an obvious positive correlation in NDVI of nature vegetation with rainfall. The correlation between temperature and NDVI is not very obvious.