Digital Earth Africa as a Platform for Coastal Erosion Monitoring along Ghana’s Eastern Coastline

Coastal erosion is a persistent and growing challenge along West African shorelines, posing serious risks to livelihoods, infrastructure, and coastal ecosystems. In Ghana, erosion along the eastern coastline is driven by strong wave action, sea-level rise associated with climate change, unregulated coastal development, and sediment retention resulting from dam construction. In response, a range of hard engineering interventions, such as sea walls, breakwaters, armour rock revetments, and groyne systems were implemented in 2017 to reduce shoreline retreat. However, systematic and cost-effective monitoring is required to assess the effectiveness and long-term impacts of these interventions. This study documents the development of a digital coastal erosion monitoring tool using the Digital Earth Africa (DE Africa) platform, focusing on Blekusu, a highly erosion-prone coastal community in eastern Ghana, where major sea-defense structures have been constructed. Relevant national stakeholders, including the Ghana Hydrological Authority, the Ghana Meteorological Agency (GMet), and the Water Research Institute (WRI), were identified through an IWMI–DE Africa stakeholder training workshop and engaged to co-create the coastal erosion use case. An ecosystem of DE Africa tools was used, including DE Africa Explorer, DE Africa Maps, and DE Africa Sandbox. The Explorer served as a unified interface to query and retrieve analysis‑ready coastline datasets and metadata (2010–2024), spanning both pre‑ and post‑intervention periods, derived from 30 m Landsat imagery and tidal modeling. The DE Africa Sandbox served as an integrated development environment for Python-based analysis, enabling users to access, process, and visualize coastline dynamics without relying on multiple external tools. Existing coastal erosion notebooks within the Sandbox were adapted, significantly reducing the learning curve and development time. Code sharing among team members facilitated collaborative development and aligned with open-access data-sharing principles. IWMI and DE Africa jointly reviewed the use case and developed online training materials that allow users to enroll, build capacity, and earn certification. Shoreline extraction and change-detection analyses revealed persistent accretion exceeding 30 m in several sections following the intervention, although localized stabilization was observed near engineered structures. These results demonstrate the reliability of DE Africa as a scalable, accessible, and cost-effective platform for coastal monitoring and support its integration into national coastal management and planning strategies. Continued investment in DE Africa and its integration into university curricula would further expand its impact across Africa.