Monitoring of Mine Tailings Ponds in Ghana: A Remote Sensing-Based Assessment

Tailings storage facilities (TSFs) pose significant environmental and structural risks, especially in mining regions with evolving landscapes. This study investigates the storage capacity changes and dam failure risks of the Dokyiwaa (Sansu) Tailings Storage Facility (TSF) at AngloGold Ashanti Mines, Obuasi, Ghana, over the period from 2016 to 2024. The study employs publicly available remote sensing data including Sentinel-2 imagery, Digital Elevation Models (DEMs), and vegetation and water indices - Normalized Difference Water Index (NDWI), Enhanced Vegetation Index (EVI) and Soil-Adjusted Vegetation Index (SAVI) this study analyses environmental dynamics and structural stability. NDWI results reveal fluctuating water levels, suggesting potential seepage and increased liquefaction risks, particularly in steep-sloped zones. EVI and SAVI analyses show a sharp decline in vegetation cover, with barren areas expanding from 134.98 m² in 2016 to over 1.13 million m² by 2024, increasing susceptibility to erosion and surface destabilization. Slope and aspect data further highlight erosion-prone areas and structural weaknesses. Findings indicate that the TSF faces escalating risks due to vegetation loss, fluctuating hydrological conditions, and unstable terrain. The study indicates the urgent need for improved drainage systems, erosion control, and rehabilitation strategies to mitigate these risks. To mitigate these risks, the thesis recommends improved drainage systems, erosion control measures, and proactive rehabilitation strategies, emphasizing the need for sustainable tailings management. The insights from this research contribute to enhancing the safety protocols for tailings dams, promoting environmental stewardship, and aligning with broader sustainability goals within the mining sector.