Remote sensing monitoring and analysis of space-time evolution of vegetation coverage in Tin Mining area - a case study from Lengshuijiang

Based on the pixel dichotomy model, the vegetation coverage is estimated by the normalized vegetation index (NDVI) using the Landsat satellite images of many years, and the spatiotemporal evolution characteristics and influencing factors of the vegetation coverage between different pollution areas are analyzed by zoning statistics. The results show that the vegetation coverage decreases gradually with the increase of the level of pollution, that is, the vegetation coverage of heavily polluted areas < that of moderately polluted areas < that of lightly polluted areas < that of clean areas. In addition, in terms of time, the overall vegetation coverage from 2006 to 2010 was poor, especially in heavily polluted areas, which were most affected by mining pollution. During this period, the vegetation coverage showed a very low level. After 2010, with the implementation of the mine restoration project, the overall vegetation coverage in heavily polluted and moderately polluted areas gradually returned to the level of 1990. This result is basically consistent with the results of the previous field sampling survey, but the cost is much lower.