Post-Mining Land Rehabilitation Using GIS and NDVI in the Northern Cape

Post-mining land rehabilitation remains a pressing challenge in South Africa, particularly in the
Northern Cape province where open-pit mining has led to extensive environmental degradation.
Despite national frameworks, few integrated systems exist for systematically monitoring
rehabilitation progress. This study addresses that gap by developing a GIS and NDVI-based model to assess vegetation recovery across three open-pit mines: Khumani (iron ore), Tshipi Borwa (manganese), and Gamsberg (zinc).
Using Landsat 7 and 8 imagery, NDVI rasters were generated for each site across three time points, supported by a structured geospatial database built in QGIS. NDVI difference maps, histograms and classified rasters quantified vegetation change, while terrain analysis using DEMs provided slope and aspect metrics to assess topographic influence. Google Earth Engine was used for efficient NDVI extraction within digitised mine boundaries.

Findings revealed distinct vegetation trajectories across sites. Khumani Mine showed significant recovery by 2019, supported by its phased rehabilitation plan. Gamsberg exhibited partial regrowth by 2025, though vegetation levels remained below pre-mining conditions. Tshipi Borwa showed persistent disturbance and minimal recovery by 2021, despite early rehabilitation efforts. NDVI difference rasters and histograms confirmed spatial patterns of degradation and regrowth, while terrain analysis indicated that slope steepness and excavation intensity influenced outcomes.
The study concludes that integrating GIS, NDVI and geodatabases provides a replicable framework for monitoring post-mining rehabilitation. All research objectives were achieved and the methodology offers practical insights for planners, policymakers and researchers seeking to improve land recovery strategies in mining-affected regions.