The Role of Space-Based Observations for Groundwater Resource Monitoring over Africa

Africa is particularly vulnerable to climate change impacts, which threatens food security, ecosystem protection and restoration initiatives, and fresh water resources availability and quality. Groundwater largely contributes to the mitigation of climate change effects by offering short- to long-term transient water storage. However, groundwater storage remains extremely difficult to monitor. In this paper, we review the strengths and weaknesses of satellite remote sensing techniques for addressing groundwater quantity issues with a focus on GRACE space gravimetry, as well as concepts to combine satellite observations with numerical models and ground observations. One particular focus is the quantification of changes in groundwater resources in the different climatic regions of Africa and the discussion of possible climatic and anthropogenic drivers. We include a thorough literature review on studies that use satellite observations for groundwater research in Africa. Finally, we identify gaps in research and possible future directions for employing satellite remote sensing to groundwater monitoring and management on the African continent.

Automated summary

Africa's vulnerability to climate change impacts, including threats to food security, ecosystem protection, and fresh water resources, highlights the importance of monitoring groundwater storage. This paper reviews satellite remote sensing techniques, particularly GRACE space gravimetry, for addressing groundwater quantity issues in Africa. The study also explores the combination of satellite observations with numerical models and ground observations, as well as quantifying changes in groundwater resources and discussing potential drivers. The literature review includes studies that utilize satellite observations for groundwater research in Africa. Gaps in research and future directions for satellite remote sensing in groundwater monitoring and management in Africa are identified.