Quantitative assessment of the effect of mining subsidence on the health of native floras using remote sensing techniques

Remote sensing technique has been used in this paper to study the effect of underground coal mining subsidence on the health condition and growth pattern of the native vegetation. The study site was an underground coal mining area of Singareni Collieries Company Limited (SCCL), India. Mining was performed in 2001, and subsidence occurred in 2001–2002. Satellite imagery of the undamaged forest before the mining subsidence was compared with the affected forest after the mining subsidence. The changes in vegetation covered areas were analyzed based on digital image classification and vegetation index. The evaluation of vegetation changes was performed for the years 2000–2005 (period 1), 2005–2010 (period 2), 2010–2018 (period 3), and the entire study period of 2000–2018 (period 4), separately. It was observed that the dense vegetation area was reduced by 16.91% during period 1 (after 3–4 years of the occurrence of subsidence), while during the consecutive later periods of 2 and 3, it increased by 24.27% and 6.59%, respectively. During the entire period 4 of the study, dense vegetation was increased by 13.95%. This would be because of natural recovery and gradual stabilization of the native soil due to the absence of human interference in the long term of time. The sparse vegetation and non-vegetated area were changed by +14.22% and +2.68% during period 1, while they were changed by -15.36%, -7.91%, and -8.91%, +1.32%, during periods 2 and 3, respectively.