Hydrogeological (groundwater) Mapping for ECOWAS region
The World-wide Hydrogeological Mapping and Assessment Programme (WHYMAP) is a joint programme consisting of a consortium composed by UNESCO, the Commission for the Geological Map of the World (CGMW), the International Association of Hydrogeologists (IAH), the International Atomic Energy Agency (IAEA), the International Groundwater Resources Assessment Centre (IGRAC), and the German Federal Institute for Geosciences and Natural Resources (BGR). Its principal aim is to contribute to the world-wide efforts to better understand, manage and protect aquifer resources, and to transfer this groundwater related information appropriately to groundwater experts as well as to non-experts and politicians.
The consortium published the Groundwater Resources Map of Africa during the 7th Africa Water Week 2018 in Libreville (Gabon). This map was very well received by policy makers and planners from Africa who were part of the Africa Water Week. During discussions, it was suggested to work for a detailed groundwater map for the sub-regions based on the regional economic communities of Africa.
In Africa, up to about 75% of the population use groundwater as the main source of water serving rural livelihoods, livestock rearing and urban water supply. Most of Africa’s large aquifer systems and transboundary and so for Seventy-two transboundary aquifers have been identified in Africa. They underlie 40% of the continent, where approximately 30% of the population live in the arid and semi-arid regions.
Based on collective request for detailed sub-regional mapping, UNESCO-IHP initiated a dialogue with other international institutions. In May 2019, a preliminary meeting was organized with other international partners such as the German Federal Institute for Geosciences and Natural Resources (BGR); the British Geological Survey (BGS); Le Bureau de Recherches Géologiques et Minières (BRGM); and the International Groundwater Resources Assessment Center, the UNESCO Category 2 Center in Delft, The Netherlands to proceed further on this request. Based on the discussions and the availability of data, it was decided to start with the Economic Community of West African States (ECOWAS) region.
Several consultations have been had with the African Ministers' Council on Water (AMCOW) and the Water Resources Coordination Centre of ECOWAS on the possibility of having sub-regional hydrogeology or groundwater map. Based on the agreement between all partners, an online consultation meeting was organised with UNESCO, BGR, BGS, BRGM, IGRAC, AMCOW and ECOWAS from 17 to 18 April 2020.
The initiative was well received, with first cooperation steps agreed. The development of the ECOWAS regional hydrogeological map will primarily consist of compilation and harmonisation of national maps, requiring coordination with national geological services.
Beside a regional hydrogeological map, it is planned to develop thematic and advocacy maps. For these maps, additional information is needed, either by deriving from the hydrogeological characterisation (e.g. storage properties) or from other aspects of groundwater assessment (social, economic, environmental, policy, etc) to estimate values of groundwater productivity, dependency on groundwater, groundwater risk and similar etc. Representatives of ECOWAS and AMCOW expressed interest primarily in a groundwater potential map and the groundwater monitoring/level map.
As a follow up, four working groups were formulated to work on a version to complete this initiative so that the Map can be presented during the World Water Forum 2021 in Dakar, Senegal.