Dynamic responses of the coalfield ecosystem to mining intensity, spatio-temporal variation, and climate change derived from AVHRR/NDVI in Shendong coalfield
Study purpose on biological productivity inverted from a long time series, the multi-dimensional Normalized Difference Vegetation Index (NDVI) in mining-disturbed areas is to understand vegetation succession of non-natural ecological areas, while to provide guidance for natural restoration and artificial restoration of the vegetation under high-intensity mining conditions northwest fragile ecological areas in China. Shendong coalfield, as a directly affected area, an indirectly affected area (20 km buffer), and a natural ecological checked area were established. Using Global Inventory Modeling and Mapping Studies Advanced Very High Resolution Radiometer derived NDVI dataset (GIMMS AVHRR/NDVI) (July 1981-December 2006, 25.5 years), combined with temperature and precipitation information (86 meteorological stations) and Shendong coal output, the aforementioned three areas are comparatively investigated for the effects of temporal, spatial, climatic, and mining intensities. Test validation is conducted by means of another long-term Moderate Resolution Imaging Spectroradiometer (MODIS: MOD17A3 and MOD13Q1) net primary productivity (NPP)/NDVI (2000~2010, 11 years) dataset. The results will provide new insights into ecological environment in mining:(1) under the background of climate change, the vegetation growing season was extended again in the Shendong mining area;(2) NDVI increment in the Shendong mining area was below the buffer, and NDVI increment in its buffer was lower than the natural ecological area;(3) In the mining area, with the increase in mining intensity, NDVI growth rate was lower than that of in the natural ecological area.