Recent Trends in Vegetation Greenness and Their Causes in Semiarid Areas of China

This paper presents regional trends in vegetation greenness in Inner Mongolia Autonomous Region, semiarid areas of China. We used NOAA GIMMS NDVI data from 1982 to 2006 to explore the relationship between vegetation greenness change and climatic and anthropogenic factors based on the analyses of meteorological data, high spatial resolution remotely sensed data and local economic statistical data. This research indicates the long-term change of increasing vegetation greenness from 1982 to 2006 in a large portion of the Inner Mongolia Autonomous Region. 17% of the study area experienced a significant increase change of vegetation greenness over the study period at the 0.05 level. The increasing greenness showed no positive link with precipitation in the study area. The increase of both the cropland area and the millet yield is responsible for the significant increase of vegetation greenness. Where the integrated NDVI showed significant increase trend, most area is crop land. For the entire study area, the cropland area increased over 50% during the study period and the millet yield of cropland per unit showed a strong increase with the regression model significant at the 0.05 level.