BASELINE ASSESSMENT OF VEGETATION COVER ALONG THE ABUJA – KADUNA RAIL CORRIDOR USING GEOSPATIAL TECHNIQUES

Abstract

This study assessed the baseline vegetation cover along the Abuja–Kaduna Rail Corridor prior to railway construction using geospatial techniques. Establishing pre-construction vegetation conditions is essential for monitoring environmental changes associated with infrastructure development and for distinguishing natural vegetation dynamics from anthropogenic disturbances. The study employed remote sensing and Geographic Information Systems (GIS) techniques using Landsat satellite imagery acquired for the year 2011. Image preprocessing involved radiometric and atmospheric corrections to improve spectral accuracy and consistency. Vegetation conditions within a 200m buffer zone along both sides of the rail alignment were evaluated using the Normalized Difference Vegetation Index (NDVI). The processed NDVI imagery was classified into five vegetation density classes: very low, low, moderate, high and very high vegetation. Spatial analysis and supervised classification were conducted in ArcGIS, while accuracy assessment was performed using field observations and GPS validation points. Results revealed that moderate vegetation constituted the dominant land cover class, accounting for 42.6% of the study area, followed by high vegetation at 28.3%. Very high vegetation occupied 5.4%, representing dense forest patches, wetlands and riparian vegetation, while low and very low vegetation covered 18.5% and 5.2% respectively, mainly around built-up and agriculturally disturbed areas. The findings indicate that the corridor was largely characterized by stable and productive vegetation cover prior to railway development. Spatial distribution patterns further revealed higher vegetation density in rural and less accessible areas, whereas lower vegetation classes were concentrated near urbanizing zones around Abuja. The study establishes a reliable environmental baseline for future monitoring and assessment of vegetation changes associated with railway construction and related land-use transformations.