Drought Assessment over Northern Africa Using Multi-source Satellite Product

Drought represents a significant threat to human and ecological systems across Africa. Historically, drought assessment relied on limited ground-based meteorological precipitation and temperature measurements. However, these cannot capture the full complexity of drought impacts on vegetation, soil moisture, agriculture, and water resources. The study focused on assessing the skill of different satellite remote sensing products for comprehensive drought monitoring in providing extensive spatial coverage of multiple drought-related variables. We utilized multiple satellite precipitation products to analyze meteorological drought patterns across Northern Africa between 2001 and 2020. Three datasets—Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) data, Climate Prediction Center morphing method (CMORPH) precipitation data, and Integrated Multi-Satellite Retrievals for Global precipitation measurement (IMERG)—were used for this study. Recent advancements have expanded monitoring capabilities through new drought indicators derived from multi-spectral sensors. However, challenges remain in maximizing the use of Earth observation data for early warning and mitigation. This chapter discussed the need for integrated drought monitoring to support evidence-based adaptation in Northern Africa’s drought-prone environments. It reviewed different satellite-based approaches for characterizing agricultural and hydrological drought, including precipitation anomalies, vegetation indices, evapotranspiration deficits, and surface water declines. While precipitation datasets like CHIRPS and Tropical Rainfall Measuring Mission (TRMM) have enabled large-scale meteorological drought monitoring, vegetation indices track delayed impacts on crop health. Operational evapotranspiration models and surface water mappings provide further insights into moisture stress. However, no indicator gave a complete view of drought propagation through climatic, ecological, and human systems. In this regard, an integrated monitoring system combining multiple indicators and datasets is required. The chapter emphasized the importance of rigorous validation and uncertainty characterization using independent ground-based data. Overall, satellite data offer new drought monitoring capabilities to help vulnerable regions anticipate and prepare for droughts exacerbated by climate change. Realizing this potential requires continued algorithm refinements, capacity-building, and seamless integration with local information to maximize early warning utility.