Quantifying the Environmental Impact of Artisanal and Small‐Scale Mining: An Integrated Approach for Sustainable Development Insights

ABSTRACT Artisanal and small‐scale mining (ASM) provides livelihoods for over 44.5 million people globally, yet its largely unregulated nature causes severe environmental degradation in host communities. In Nigeria, where ASM accounts for over 90% of solid mineral production, the sector increasingly encroaches on agricultural land. Despite growing recognition of ASM's environmental impacts across West Africa, no study has yet applied the novel SDGSAT‐1 satellite purpose‐built for SDG monitoring at 10 m resolution to quantify ASM land degradation in Nigeria, and few studies simultaneously integrate multi‐sensor remote sensing, in‐situ soil contamination assessment, and hydrological transport modelling within a single integrated framework. This study addresses that gap. This study integrates SDGSAT‐1 Multispectral Imager and Landsat 9 imagery (both acquired 12 January 2024) with field‐based soil sampling (November 2023, dry season) and GIS hydrological modelling for Igbojaiye community, Oyo State, Nigeria. Eight vegetation, water and soil indices (NDVI, EVI, SAVI, TSAVI, TVI, NDWI, BSI) and Land Surface Temperature were derived from satellite imagery. Soil samples from eight mining‐affected points and four undisturbed control points were analyzed for physicochemical properties and heavy metals (Fe, Pb, Zn) using Atomic Absorption Spectrometry. Contamination Factor, Geoaccumulation Index, Pollution Load Index, and a Potential Ecological Risk Index were computed. A Digital Elevation Model was used to delineate contaminant transport pathways. ASM‐affected areas exhibited severe vegetation loss (68% of land within 500 m of mining pits classified as Degraded; mean NDVI −0.08 vs. +0.18 in control areas) and elevated Land Surface Temperature (mean 35.2°C ± 1.3°C vs. 28.9°C ± 0.8°C in controls). Mining soils showed markedly degraded physicochemical properties (organic carbon 4× lower, moisture 5× lower, pH more acidic). Lead exhibited very high contamination (mean Contamination Factor 10.0; Geoaccumulation Index Class 3: moderately to heavily contaminated) with a statistically significant distance‐decay gradient ( r = −0.60, p = 0.04). No metal exceeded WHO/FAO soil limits in absolute terms. Hydrological modelling identified direct flow pathways from mining pits to downstream farmland and waterbodies. ASM in Igbojaiye initiates a cascade of compounding degradation, soil toxicity, microclimatic disruption, and hydrological pollutant dispersal that collectively undermine agricultural productivity and water security, directly impeding SDGs 2, 6, 13, and 15. This study represents one of the first applications of SDGSAT‐1 for ASM monitoring in Nigeria, establishing a replicable multi‐sensor framework for evidence‐based environmental governance of ASM in data‐scarce sub‐Saharan African contexts. Remediation priorities include sediment traps at mining pit outflows, phytoremediation with native metal‐tolerant species, and satellite‐based biannual monitoring protocols.