Changes in vegetation cover and water bodies due to artisanal mining in the Huancaray micro-watershed, Andahuaylas, Peru (2006–2024)

Abstract

The expansion of artisanal and small-scale mining (ASM) represents an increasing pressure on fragile headwater ecosystems due to its potential effects on land cover associated with hydrological regulation and the provision of ecosystem services. This study evaluates changes in vegetation cover and water bodies associated with the expansion of ASM in the headwaters of the Huancaray micro-watershed (Andahuaylas, Peru) during the period 2006–2024. A multitemporal analysis of Landsat and Sentinel satellite imagery was conducted using spectral indices (NDVI, MNDWI, NDBI, and NDSI) integrated into a supervised classification based on the Support Vector Machine (SVM) algorithm. Model accuracy achieved Kappa index values ranging from 0.73 to 0.88, indicating good to very good agreement. The results show a sustained expansion of areas associated with ASM, accompanied by a progressive reduction in vegetation cover and water bodies. Linear regression analysis indicated that mining expansion is associated with 75.3% of the observed variability in vegetation cover loss and 80.3% of the variability in the reduction of water bodies. These findings suggest that ASM constitutes a factor closely associated with the transformation of the high-Andean landscape and provides a replicable methodology for environmental monitoring, with implications for land-use planning, mining enforcement, and the conservation of fragile ecosystems.