Under the GGRETA-3 project, the national hydrogeological maps of Mozambique and Zimbabwe have been georeferenced and vectorized. The shapefiles of both maps have been made available for download in the SADC Groundwater Information Portal (SADC GIP). The SADC-GIP already contained the hydrogeological maps of eSwatini and Lesotho, which have been georeferenced and vectorized in the last few years. All these maps in GIS-compatible format will support the management and the development of groundwater resources in the countries, and facilitate transboundary cooperation in the region.
Georeferencing and vectorizing hydrogeological maps
Hydrogeological maps are a cornerstone for groundwater assessment and hydrogeological studies. However, a recent inventory of national hydrogeological maps in Africa has shown that many national hydrogeological maps are old and only available in image format. They can not be used in GIS programs for the sake of visualization and geospatial analysis.
In order to use hydrogeological maps in GIS programs, it is necessary to georeference the original image of the map and vectorize the features shown on the map, such as hydrogeological units (polygons), geological structures (polylines) or wells (points). The attribute tables of these layers and the symbology files also need to be created.
Once in a geospatial vector data format, like the ESRI Shapefile format, the maps can be used in GIS programs, where they can support a wide range of applications, such as groundwater management and development. They are instrumental for transboundary assessments like in transboundary aquifers studies. Such maps can also be more easily updated.
The project “Groundwater Resources Governance in Transboundary Aquifers” (GGRETA) was funded by the Swiss Agency for Development and Cooperation (SDC) and coordinated by the United Nations Educational, Scientific and Cultural Organization (UNESCO). In the third phase of the project, which ended up in December 2022, project activities were carried out across Africa to support the integration of groundwater management in river basin organizations. Georeferencing and vectorizing the hydrogeological maps of Mozambique and Zimbabwe was a contribution to groundwater management in the Limpopo River Basin. The project activity was carried out in close collaboration with Kartoza, a South Africa-based Free and Open Source GIS (FOSGIS) service provider.
Download maps Mozambique and Zimbabwe
The resulting GeoPackage files containing all GIS layers and styles can be downloaded from the SADC Groundwater Information Portal (SADC-GIP):