Study On Temporal And Spatial Variation And Influencing Factors Of NDVI In The Yellow River Basin Of Inner Mongolia

This thesis is based on NDVI time series data in arcgis10 With the support of 2,the temporal and spatial pattern and evolution trend of vegetation index in the Yellow River Basin of Inner Mongolia are analyzed by using the methods of mean value method,coefficient of variation method and dynamic degree analysis;Based on meteorological data,population and GDP data,the relationship between vegetation index change and climate factors and non climate factors(population and GDP)is revealed by using biased correlation analysis and spatial quantitative analysis.The main conclusions are as follows:(1)The association of NDVI with time period was greatest in the growing season,with a larger annual growth rate of NDVI of 0.023/10 a in autumn.The spatial distribution of the average NDVI is high in the east and low in the west,and the average NDVI first increases and then decreases from south to north.(2)The land resources of the covered species of tall plant communities showed a steady upward trend,and the key was the conversion of the land resources of the medium and tall plant communities.The center of gravity of high-vegetation land resources is moved 128.05 km to the east.The plant community in the River Basin of Inner Mongolia Autonomous Region has been significantly restored,but there are still sporadic decline areas,and the key points are scattered in the development core of the city.The total area of slight NDVI decline in spring was higher than that in autumn and winter.From May to October,the NDVI in the River Basin of Inner Mongolia Autonomous Region showed high fluctuations,with moderate fluctuations in spring,relatively large fluctuations in summer,and relatively large fluctuations in autumn.(3)The annual precipitation shows a trend of gradual fluctuation and growth,and the annual average temperature gradually decreases,but the decline is not large.There was a high correlation between annual precipitation and annual NDVI,according to the significance test of P<0.05;there was no significant correlation between temperature and annual NDVI.The partial correlation analysis between annual precipitation and temperature shows that the partial correlation degree of annual precipitation is high,and the local area is significantly inversely proportional;The quantitative analysis of NDVI change trend of GDP and population shows that the higher the level of population and GDP,the higher the proportion of significantly degraded area in the graded unit area.