Assessing land degradation susceptibility in a mining landscape of ghana using geospatial techniques and soil organic carbon

Abstract

Land degradation is on the ascendency in mining related environment posing significant treat to ecosystem functioning and services. This study assessed land degradation in the Birim North Mining District of Ghana. It utilized a geospatial multi-criteria technique merging remote sensing, GIS, Analytic Hierarchy Process, and Soil Organic Carbon stock. Eight factors–Land Use and Land Cover, Normalized Difference Vegetation Index, precipitation, slope, elevation, drainage density, geology, and soil organic carbon stock–were weighted to generate a land degradation susceptibility map. Satellite imagery (2010-2024) at five-year intervals revealed a 50.22% decline in forest cover, a 289.21% increase in built-up areas, and the emergence of 13.73 km² of mining sites. Additionally, 61 stratified soil samples taken at a depth of 0–30 cm were analyzed to estimate soil organic carbon stock via laboratory analysis and geostatistical methods. Forested areas recorded the highest soil organic carbon stock (13.422–27.2946 t/ha)) while mine sites exhibited the lowest soil organic carbon content (0.6976–2.3947 t/ha). Total carbon stock under cropland was 135543.1429 t/ha. The land degradation map classified the landscape into five susceptibility zones: very low, low, moderate, high, and very high degradation. Very high degradation zones largely overlapped with mining areas, while 24.6% which is 139.47 km² of the area, mostly forested, exhibited very low degradation. This study demonstrates the effectiveness of integrating geospatial techniques and Analytic Hierarchy Process for land degradation assessment and provides a baseline for targeted interventions. Findings highlight illegal mining activities and rapid urbanization are the primary drivers contributing to land degradation, resulting in reduced vegetation cover, soil erosion, and reduced soil fertility. Addressing land degradation through sustainable land management is essential to mitigate further environmental and socio-economic consequences. • A geospatial multi-criteria approach assessed land degradation in Birim North. • multi-temporal satellite imagery (2010–2024) showed 50.22% forest loss and 289.21% built-up expansion. • Soil Organic Carbon (SOC) was lowest in mining sites (0.296-0.951%) and a carbon stock of 0.6976-2.3947 t/ha. • AHP and GIS analysis found 7.32% of the area highly degraded, mainly in mining zones. • Results provide baseline data for targeted land restoration and management.