Temporal and Spatial Changes of Vegetation during the Growing Season and Its Correlation with Climate Factors in Jiuquan Area of Qilian Mountain National Park
Based on the extraction and analysis of image-by-pixel information of satellite remote sensing image data including Landsat 5TM images,Landsat 7 ETM+images,and Landsat8 OLI images with a spatial resolution of 30 meters,combining with corresponding meteorological data,the temporal and spatial changes of vegetation during the growing season in Jiuquan area of Qilian Mountain National Park from 2006 to 2021 were studied by means of mean value,slope analysis,least square method and correlation analysis studied by means of mean value,slope analysis,least square method and correla-tion analysis.The results showed that:(1)Climate factors such as temperature and precipitation domi-nated the normalized difference vegetation index(NDVI)variation trend during the vegetation growth season in the Jiuquan area of Qilian Mountain National Park;(2)On a long-term series,the annual var-iation of NDVI during the vegetation growth season in the Jiuquan area of Qilian Mountain National Park from 2006 to 2021 generally increased at a rate of 0.19%/a,with spatial characteristics of signifi-cant increase on the north and south sides,slight increase in the middle,and basically unchanged in other areas;(3)On a short time series,the annual variation of NDVI during the vegetation growth sea-son in the Jiuquan area of Qilian Mountain National Park showed a decreasing trend from 2006 to 2011 and from 2016 to 2021,while the annual variation of NDVI showed an increasing trend from 2011 to 2016.
Qilian mountain national parkJiuquan areaVegetationTemporal and spatial changesND-VIClimatic factors