Land Degradation Induced by Quarry in the Greater Jos, Plateau State, Nigeria

Abstract

This paper assesses quarry induced land degradation in the Greater Jos area of Plateau State, Nigeria, using an integrated geospatial framework that brings vegetation condition, terrain modification and soil erosion risk into a single analysis. Landsat imagery was used to derive Normalized Difference Vegetation Index (NDVI) conditions for 1994 and 2024, ASTER Digital Elevation Model (DEM) data supported elevation change analysis, Sentinel 1 Synthetic Aperture Radar supported land subsidence assessment, and the Revised Universal Soil Loss Equation (RUSLE) was applied using soil erodibility, rainfall erosivity and slope related factors. The resulting layers were standardized and integrated through a weighted overlay model. The DEM difference ranged from ­22.2548m to +95.9155 m, showing substantial excavation and deposition around quarry zones. Maximum NDVI declined from 0.53 in 1994 to 0.39 in 2024, a reduction of about 26 percent in peak vegetation vigour. The LULC analysis further revealed notable changes in land-cover patterns between 1994 and 2024, providing important land-use context for interpreting quarry-induced vegetation loss and the spatial pattern of degradation. Land subsidence ranged from minus 0.42m to plus 0.04 m. RUSLE estimated soil loss from 918.63 to 1,214.42 t ha⁻¹ yr⁻¹, with the highest erosion risk concentrated in the southern and southwestern quarry corridor. The composite map shows moderate to very high degradation clustering around intensive quarry operations, particularly the Vom, Shen and Mararaba Jama’a axis. The convergence of NDVI decline, DEM alteration, subsidence and RUSLE erosion risk demonstrates that quarry induced degradation is a multi-process landscape problem rather than a single indicator phenomenon. The study recommends routine geospatial monitoring, enforced rehabilitation, erosion control and stronger environmental compliance around active and abandoned quarry sites.