Digital earth Africa fractional cover products for monitoring land productivity trajectory

Abstract

This study evaluates the suitability of Fractional Cover products for monitoring land productivity trajectory in support of Land Degradation Neutrality (LDN) reporting in Africa. Fractional Cover quantifies the proportional presence of Photosynthetic Vegetation (PV), Non-Photosynthetic Vegetation (NPV), and Bare Soil (BS), providing an alternative to commonly used vegetation indices such as the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Modified Soil Adjusted Vegetation Index (MSAVI). A case study was conducted in the Mion District of northern Ghana using statistical, spatial, and network-based analyses to compare Fractional Cover outputs with conventional indices. Pearson correlation analysis showed strong agreement between PV and NDVI (r = 0.99), EVI (r = 0.94), and MSAVI (r = 0.97). Spatial correlation mapping and network analysis further demonstrated distinct clustering of vegetation- and soil-related metrics, with PV effectively capturing gradients in vegetation productivity and BS identifying areas of exposed soil. NPV exhibited intermediate behavior associated with transitional land-cover conditions. Overall, the results indicate that the DE Africa Fractional Cover product provides a robust and complementary approach for assessing land productivity trajectory and surface condition, supporting operational monitoring and national LDN reporting.