Analysis On The Relation Between NDVI And Climate Change In Northwest Arid Area From 1981 To 2001

Vegetation is very important by carbon-cycle on global land. And climat–change affects the growth and photosynthesis of vegetation. The change of vegetal index can reveal the evolvement of environment.Long-term quantitative analysis of vegetal distribution and change will tell us the reason of environment change. This paper discusses and analyses the change of vegetal cover and its response to climate-change by means of"3S"technique and statistics based on ecology and environment science .Here is the conclusions:First. The annual max NDVI increases in northwest arid area from 1981 to 2001. But it decreases from 1981 to 1991, and increases from 1992 to 2001, especially in the north of Xinjiang. Its change is not very evident in Gansu and Neimeng, and decreases in Qinghai.Second. The meteorological factors all increase from 1981 to 2001, and the increase is evident from 1991 to 2001 than from 1981 to 1991.South Xinjiang is more and more humid, and Gansu Neimeng becomes warming. Last. The change of annual max NDVI is affected by climate in northwest arid area especially in Xinjiang and Qinghai. And NDDVI is positively correlative with precipitation and humidity, but negatively correlate with temperature in northwest arid area except Gansu and Neimeng. Water resource is the most important factor to vegetation growth and ecology construction. We must make good use of water resource in order to achieve the sustainable development of northwest arid area.