Characteristics Of Vegetation Spatial Distribution In Qaidam Basin

The Qaidam Basin is an arid inland basin in northwest China, it is rich in mineralresource and is called Cornucopia in the world. Qaidam Basin was approved as oneof the first thirteen national pilot zones of circular economy, China will increase thedevelopment relying on the resources potentiality. However, with little precipitation,the eco-environment of Qaidam Basin is fragile and the investigation of waterresources is limit. In order to increase the reasonable development of the basin andimprove the investigation of the water resources, research on the eco-environment ofthe basin is very important. Based on the vegetation index of NDVI, this paperanalyzed inter-annual variation and regional variation of vegetation in the period of2000to2011, and took vegetation in2010as the main research object, the paperanalyzed annual variation of vegetation. Furthermore, it discussed the correlations ofvegetation and meteorological, topography, elevation, groundwater factors.The result indicated that:(1) The annual average maximization NDVI is smaller,mainly varied in the range of0.12to0.18in the Qaidam Basin. The NDVI of theQaidam Basin increased between2000and2011.(2) NDVI changes within theQaidam Basin shows a single peak, it was biggest in July, and it’s smallest in Januaryand February. It was symmetrically distributed with NDVI of July (3) During these12years, the change of vegetation of the Qaidam Basin is not big, it was appeared severedegradation and significantly improved in few areas. Significant improvementregional was distributed in the east and northeast mountainous areas of the basin. Thelittle NDVI change areas were distributed in middle part and west desert area of thebasin.(4) The of meteorology factors on vegetation distribution is mainly byprecipitation and temperature. Inter-annual precipitation and vegetation growthchange simultaneously, and the annual precipitation has hysteresis effect onvegetation growth.(5) It is found that NDVI reaches the maximum value in3950mwhen the elevation varies between3200m and5100m. In summer, vegetation ofshady side is better than sunny side, and vise versa in winter.(6) The groundwaterdepth has effect on the vegetation when the groundwater depth varies between0and5m.(7) There is close relationship between vegetation and evaporation. In general, evaporation is high in the areas with good vegetation cover. Meanwhile, the NDVIthreshold of dividing bare soil and vegetation cover area is0.05.