Monitoring Post-Mining Reclamation Success in Jharia Coalfield Using Geospatial Technology

The widespread usage of coal for power generation necessitates continuing mining. While producing a valuable resource, this method significantly degrades the natural environment, notably the local vegetation. Once mining has stopped, reclaiming the destroyed areas to restore the natural landscape is critical. Mining activities have been going on for centuries; however, monitoring reclaimed areas through field-based methods is inefficient and time-consuming. In contrast, the expanding accessibility of geospatial data over the last five decades has aided in the accurate and consistent mapping and monitoring of reclaimed mining zones. Keeping in line, the present study utilized Landsat TM/OLI data from 2005 to 2021 to track reclamation success in a part of Jharia Coalfield, India. The methods included deriving Normalized Difference Vegetation Index (NDVI) images to evaluate the spatiotemporal variation of vegetation health, density, and vigour; and visual appreciation using a variety of RGB combinations of three date NDVI images. Later, a statistical threshold method based on Z-scores was employed to quantify the NDVI change values into three categories- Decrease, Unchanged and Increase. According to these analyses, the reclamation success in the study area ranged from modest to good. In the two focus areas, there has been an increase of 72 and 76 hectares in the Increase class. The accuracy of the classified change image was calculated to be 84.4 per cent. Until recently, no such work has been reported from the study area. The present research results are critical to mining professionals, environmentalists, and society and provide a promising way to inform about the success of reclamation activities and their monitoring.