Assessing two decades of change across the Eco-Regions of West Africa using remote sensing technology

Abstract

The landscapes and Eco-Regions of West Africa have a unique biodiversity that reflects climatic regime and human interaction. Changes and trends in the Eco-Region land cover and its productivity was assessed using Aqua MODIS NDVI C6 satellite images on a geographical mapping grid at approximately 250m from between 2003 and 2021. Using cell statistics and geoprocessing tools within a GIS environment, the satellite images were processed and analysed. The processed and analyzed satellite images document changes across the region over 19 years. The results show that; Guinea Savanna Eco-Region records highest changes, with an increase in green productivity between 2007 and 2012 by 9.24 km2; and decrease in green productivity in green productivity between 2007 and 2012 by 9.24km of 4.37 km2 from 2012 to 2017 and by 9.30 km2 from 2017 to 2021. The Grassland/Sudan Savanna fluctuated over the last 19 years with an overall reduction in green productivity by 3.43 km2 while the Guinea Savanna increased by 1.0 km2 over the same period. The Tropical Rainforest Eco-Region had the highest increase in productivity from 2003 to 2007 by 11.25 km2 and less than a km2 increase from 2007 to 2012. This study concluded that there was fluctuation in area coverages among the Eco-Regions across West Africa which varies seasonally and periodically. These Eco-Regions are vital for the development and economic suitability of West Africa, thus the need for continuous monitoring and study. Also, the fluctuation in area coverages detected in the study suggest that certain interventions by policy makers and stakeholders have brought about these changes, of which reforestation and land use policies are inclusive. Policymakers and government agencies are therefore apprised to maintain policies that support green productivity in the region.