Analysis of land cover change on soil organic carbon stock for detecting environmental degradation in Nigeria landscape

Abstract

The analysis of land cover change (LCC) is among the pressing environmental solutions for assessing location-specific information on soil organic carbon (SOC) stocks. The objective of this study was to investigate the impact of LCC on SOC stocks in Ewekoro, Nigeria, using remote-sensing techniques. Thirty clustered soil samples (0–30 cm) analyzed for SOC and bulk density were subjected to the kriging method. LCC maps for the years 2004, 2014, and 2024 were generated using a support vector machine (SVM) algorithm, incorporating spectral environmental indicators including the digital elevation model (DEM), normalized difference vegetation index (NDVI), and salinity index (SI) from Landsat 7 and 8 satellite images. The study showed a significant increase (0.6%) in the barelands from 2004 (1.4%) to 2024 (36.9%), followed by a substantial increase in built-up areas. In contrast, vegetation cover declined drastically (26.1%), followed by wetlands (1.6%), and water bodies (1.4%). SOC stock values of the area ranged between 16.7 (low) and 77.2 (high) t ha⁻¹ with a mean of 32.8 t ha⁻¹. The findings from this study call for an urgent need to alert policymakers around population growth to step up adaptation and mitigation interventions to balance development and environmental preservation in this climate-vulnerable landscape.