Land Cover Maps for Regional Climate Modelling in West Africa - A comparison of Datasets

摘要

Land cover is related to a number of biogeophysical land surface properties and therefore has an influence on surface fluxes of water and energy. In many climate impact studies, land cover maps are used to estimate land surface properties that are needed to describe relevant land surface processes. Currently, several global or continental land cover maps are available which can be used for this purpose. These maps have been created from remote sensing data of different instruments and years, using different classification methodologies and legends. Discrepancies between these maps can lead to differences in attribution of land surface properties and subsequently to inconsistent results of climate studies. Here, four global and continental land cover maps are harmonized and compared for West Africa. After harmonization, selected land surface properties (seasonal minimum and maximum of leaf area index (LAI), albedo, roughness length and fraction of vegetation cover) are derived based on a standard dataset which is commonly used during data preparation for the Weather Research and Forecasting (WRF) model. The resulting spatial patterns of land surface properties exhibit major discrepancies in regions of agricultural land use, in savannas and in the transition zones between savannas and deserts of West Africa.