Vegetation Coverage Variations And Its Mechanism Based On Remotely Sensed Technology On Shanxi Plateau

Vegetation plays a critical role in global climate change, it has the very vital significance for assessing the ecological environment of Shanxi plateau, guiding the vegetation restoration and construction of Shanxi plateau and maintaining biodiversity to analysis the space-time evolution characteristics of vegetation activity of Shanxi plateau and its driving mechanism. Shanxi plateau is located in the east end of loess plateau, it has complex terrain and sparse vegetation,water loss and soil erosion is serious. It is necessary to study the change trend of regional vegetation activity and the driving factors for improving ecological environment of Shanxi and realizing the sustainable development of regional economic development and ecological environment.Acting Shanxi plateau as study area, based on remote sensing technology and geographic information system platform, using long time series of GIMMS NDVI and MODIS NDVI data, combined with precipitation and temperature data, land use map, topography data, using one variable linear regression analysis, correlation coefficient, and residual analysis, The space-time evolutiontrend of vegetation activity was revealed in detail on Shanxi plateau from 1982 to 2011, and the driving mechanism was analyzed from two aspects of climate change and human activity. Here get the main conclusions:(1) The vegetation activities was on the rise with interannual variability as a whole from 1982 to 2011 in Shanxi plateau. The mean NDVI is on the rise in spring, summer, autumn and winter seasons, there was a significant increase in spring season.(2) The spatial pattern of interannual stability of vegetation change is from southeast to northwest, the same as the pattern of vegetation coverage. The regions of good coverage are improved significantly, the vegetation types are mainly composed of farmland and grassland, the regions of poor coverage are degraded significantly, the vegetation types are mainly composed of woodlands and brush.(3) The combination of rainfall and temperature act on vegetation activity in Shanxi plateau together. The region of significant relation between vegetation activity and temperature is distributed in the higher mountains, the region of significant relation between vegetation activity and precipitation is distributed in all the basins. There are 1-2 month lag between vegetation activity and precipitation in large parts of Shanxi plateau. There are 2 monthly lag between vegetation activity and temperature in large parts of Shanxi plateau in May,vegetation activity is associated with current month significantly in most part of Shanxi plateau from June to September.(4) The NDVI residual is decline overall with interannual variability in Shanxi plateau from 1982 to 2011.There are both positive effects and negative effects from the influence of human activities on vegetation change, from the spatial distribution, the area of positive effect is slightly less than the area of negative effects overall. The positive role is mainly shown to woodland by human activities; the positive effect on forest land is obvious weakening. There are both positive effects and negative effects by human activities on the grassland and farmland.Using remotely sensed data, the space-time evolution of Shanxi plateau vegetation in 30 years and drive mechanism were analyzed in detail, It showed that vegetation changes are the result of the combination of climate and human activity, we must strengthen the protection of vegetation to improve our living environment.