Vegetation Dynamics in Open Cast Mining-Dominated Regions of Eastern India: Insights from Time-Series Landsat Satellite Data

Abstract

Monitoring the trajectory of vegetation changes is crucial to comprehend mining-induced vegetation degradation and assess ecological restoration's efficacy, thereby promoting regional sustainable development. Mineral-rich states in Eastern India, notably Jharkhand and Odisha, host numerous open-cast mining sites, driving significant vegetation degradation. This study employed Landsat satellite data spanning 32 years (1988–2020) to gauge vegetation trends in these mining-dominated regions using the Mann–Kendall (MK) test. The analysis occurred over two focal periods: 1988–2004 (earlier period) and 2000–2020 (later period). Cloud-free annual NDVI mosaics were generated using the Google Earth Engine (GEE) platform. The MK test was then applied in R-CRAN software on NDVI datasets (pixels with NDVI > 0.2 and < 0.9). Findings of the study revealed that approximately 2.97% (1285 km²) and 3.91% (1688 km²) of Jharkhand's total vegetation cover, and about 5.68% (5213 km²) and 3.20% (2940 km²) of Odisha's, exhibited negative vegetation greenness trends (indicating declining vegetation activity) during 1988–2004 and 2000–2020, respectively. Open-cast mining activities accounted for approximately 3–6% of vegetation degradation across both states. Considering 61 mining locations within a 2 km buffer zone, negative vegetation greenness trends spanned approximately 74 km² in the earlier period, growing to 170 km² in the later period. Most mining locations demonstrated 10–20% vegetation recovery within the degraded area (2 km buffer zone) during the study periods. On the other hand, climatic factors such as rainfall, temperature, downward radiation, and soil moisture had a modest impact (~27%) on long-term vegetation growth in mining-dominated regions, contrasting with their more significant influence (~47%) in typical forested areas. The outcomes of the present study inform policymakers, stakeholders, and government bodies, supporting sustainable ecosystem management and socio-economic development policies in mining-dominated regions to conserve vegetation and enhance ecological services.