Croplands in West Africa: A Geographically Explicit Dataset for Use in Models

Abstract

West Africa has experienced increases in cultivated lands over the last 50 yr, as well as increasing rates of deforestation. Croplands have expanded to meet the food demands of a rapidly increasing population. Nevertheless, this region remains one of the most food-deprived places on the planet. While the food demands of an increasing population have to be met through cropland expansion or intensification on existing lands, it is important to evaluate the long-term environmental consequences of the ensuing land-use change. Spatially explicit datasets of land use/land cover for the region would be valuable for assessing the environmental consequences of land-cover change, as well as the implications for food security. A review of the currently available moderate-resolution satellite-derived land-cover datasets for the region finds them to be of poor quality. A high-resolution satellite-derived cropland dataset for the Sahel is available; however, extending this to the entire West African region is an expensive proposition and will require a massive undertaking. Therefore, in this study, a new regional dataset of the spatial distribution of croplands for West Africa was created by synthesizing subnational cropland area statistics, a spatial map of population density, and a high-resolution satellite-derived cropland intensity dataset for the Sahel. The new dataset appears to be an improvement over the existing datasets of cropland distribution and is proposed here as a provisional product for use within numerical ecosystem or climate models, as well as for spatial analysis of land degradation, soil nutrient balance, food security, etc.