UNESCO Regional Office for Eastern Africa - Nairobi Science Sector

The harmonized geological and hydrogeological of the Horn of Africa integrates layers initially provided by the World Bank, which were developed from regional and national maps published by the British Geological Survey (BGS). These foundational layers, including detailed geological and aquifer type and productivity maps, were adapted to align cross-border geological formations and hydrogeological units. Through this harmonization, geological formations were reclassified by stratigraphic age and lithological properties, ensuring consistency in representation across Ethiopia, Djibouti, Kenya, Somalia, and South Sudan. Aquifer types and productivity levels were systematically standardized to reflect groundwater flow mechanisms, such as intergranular or fracture flow, and productivity classifications from very low to very high. The harmonized map employs consistent color schemes and attribute codes, allowing for streamlined GIS integration, cross-border assessments, and enhanced water resource management in the Horn of Africa.