The Omusati region is partially irrigated by a canal coming from the Kunene River (Omusati, 2018).
© BRGM - Alexis Gutierrez
Issues and needs
In order to help Namibia be better prepared to manage droughts, which are becoming increasingly critical due to the country's growing population and rising living standards, the operators in charge of water management need to receive relevant training, and the general understanding of the country's water resources needs to be improved. To be able to manage the resources efficiently requires acquiring knowledge about the aquifers through field operations and major surveys, while also improving the level of understanding and assimilation of this knowledge among the representatives of the Government Services that are actually in charge of managing and exploiting these resources. The project is being funded by the French Development Agency (AFD).
A country that regularly faces droughts
Namibia is the driest country in Southern Africa. The level of rainfall in Namibia is low, and can vary greatly in terms of frequency and coverage. Moreover, it is unevenly distributed across the country. The average annual rainfall decreases from over 600 mm/year in the Zambezi (Caprivi) region in the far north-east, to less than 50 mm/year in the south and west of the country. The national average rainfall is approximately 270 millimetres.
Namibia regularly faces drought crises. The population of Namibia is approximately 2.5 million. With a surface area of 825,615 km2 (1.3 times the size of France), the population density is 3 inhabitants/km2, although this figure hides the fact the population is spread across the country very unevenly. For historical reasons, rural population groups (57% of the population) are concentrated in certain regions, particularly in the north (Owamboland).
The majority of Namibia's water supply comes from surface water that is diverted into dams. However, on a national scale, the use of groundwater is also quite significant (estimated at 43% by Namwater). Some regions use groundwater intensively, whereas others only use it when surface resources are scarce. Drought management is therefore based on threshold criteria concerning dam levels.
Two Namibian ministries – the Ministry of Agriculture, Water and Land Reform (MAWRL) and the Ministry of Environment, Forestry and Tourism (MEFT) – were particularly interested in setting up a training programme during the first 6 months of the project. Consequently, seven one-week training modules have been organised for staff in these ministries in the disciplines of hydrogeology. After this, with the help of BRGM experts, these Namibian government officers will be involved in completing tasks 2 and 3 of the project, respectively devoted to studying the impact of climate change on water recharge in the Omusati and Kunene regions, and drawing up a water-resource forecasting map for these regions.
The Kunene River which forms Namibia's northern border with Angola (Ruacana, 2018).
© BRGM - Alexis Gutierrez
Development of a water-resources forecasting map
BRGM aims to contribute to the ongoing process aimed at implementing a system for forecasting and managing drought episodes by developing a water-resource forecasting map for the provinces of Omusati and Kunene, which are particular priorities for the Namibian government because they have a large number of inhabitants and a dynamic agricultural sector. These regions have very different hydrological and hydrogeological environments and will therefore serve as good examples to demonstrate what a forecasting map can achieve. The local authorities underlined the importance of the various issues involved (high population density, various uses of the water resource, need for high-quality water resources) during an initial assessment mission in 2018.
The approach proposed by BRGM differs from the traditional studies carried out (and resulting maps) in the field of groundwater, which are generally highly technical and focused on one subject, and therefore not effective as decision-making tools. Traditional studies do not include all the different aspects that are essential for forecasting and managing the resources available. Decision-makers need to have simple, relevant tools that answer key questions: Where are the groundwater resources and the surface water resources? Are they readily available? Do they need to be treated before use? Can they be exploited in a sustainable or economically viable manner? A water-resource forecasting map provides a simple way to visually summarise the existing information on these subjects.
- MAWLR (Ministry of Agriculture, Water and Land Reform)
- MEFT (Ministry of Environment, Forestry and Tourism)
- And various other stakeholders, such as Namwater, Geological Survey of Namibia, Regional councils, and the University of Namibia.