Integrated environmental impact assessment of the Sasa tailing dam failure using remote sensing techniques

Failures of tailings dams represent a critical environmental hazard, releasing mining by-products that cause long-term damage to nearby ecosystems. This research presents a detailed analysis using remote sensing techniques of the 2003 Sasa tailing dam disaster in North Macedonia. By utilising Landsat 5 imagery and Google Earth Engine (GEE), multiple spectral indices-including Normalised Difference Vegetation Index (NDVI), Normalised Difference Moisture Index (NDMI), Normalised Difference Water Index (NDWI), Modified NDWI (MNDWI), and a turbidity proxy-were integrated to examine the immediate and spatial impacts on vegetation health, soil moisture, water presence, and sediment levels.
The findings indicated that the degree of ecological fluctuation of the river path was high in terms of vegetation stress, changes in soil moisture, water pooling, and turbidity.
These effects showed spatial gradients, with the impact reducing further from the contamination pathway, forming distinct zones of influence. Some areas at intermediate distances showed anomalous disturbances, combining sediment and hydrological changes that obstruct vegetation recovery. Pixel-level, buffer-based, and zone-based analyses, with Z-scores and correlation studies, revealed complexity in post-disaster landscapes. Importantly, the weak correlation with topographic features suggested localised conditions, rather than broad gradients, governed short-term ecological recovery.
These results provide valuable insight for policymakers, demonstrating how multi-index and multiscale approaches are necessary to capture the varied ecosystem responses to tailings dam failures. This study offers a framework for other disaster sites and promotes better-targeted remediation, informed disaster planning, and sustainable management of post-mining landscapes in a rapidly changing global context.