Background information on the geology of Kenya
The geology of Kenya shows Metamorphic rocks in the western part due to high metamorphic processes. The Great Rift Valley is a plate boundary.
Tertiary and Quaternary Volcanic Rocks: East African Rift System: volcanic activity during these periods
Resources used for addressing the challenge
Map of community locations
Software
- QGIS: A Free and Open Source Geographic Information System. Version 3.32.3 / Version 3.28.11 LTR.
- ArcGIS Pro. Version ArcGIS Pro 3.
Data sources
- National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/national-atlas-kenya-geological-map (visited: 19.10.2021).
- Samburu District - Type and Location of Water Sources, Key Landforms, and Soils (Symbols - See Map 11). (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/samburu-district-type-and-location-water-sources-key-landforms-and-soils-symbols-see-map-11 (visited: 19.10.2021)
Publications used for methodology and background research
see references indicated below.
Steps outlining the solution
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To find where water is situated, compare a topographic map with the Normalised Differentiated Vegetation Index (NDVI). Recharge occurs where water accumulates and hence vegetation is available/the healthiest at the driest times. This step could be implemented using Google Earth Engine.
Figure 3: Topographic map of Samburu province in Kenya. Credit: Topographic Map (2023) 
Figure 4: NDVI made with QGIS. Version 3.32.3 / Version 3.28.11 LTR. - Develop a geology map and potentially a geophysical survey (mineral composition). Mineral data and geophysical characteristics are well mapped in Kenya. It is likely that the geology in Kenya requires a basement rock drilling using air hammers / air compressors and pneumatic hammering.
Figure 5: Zoom into Samburu county at the National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre. Orange: Basement rock, Yellow Quarternary Sediments. - The communities are located in the South-West of Samburu County. The geology in the area is mostly magmatic and metamorphic. This suggests that the ground has very low permeability. However, near the location of the communities there are two springs. These springs point to an aquifer in the area, where a well for the communities in the area could be developed. ---
Figure 6: Water sources in the Samburu county. Map provided by Kenya Space Agency. Source: G. de Sourza, Dept. Geography, University of Nairobi, J. Keza, Ministry of Water Development.
- A desk study compares the geology with the topography
Figure 7: Geology of Samburu County Krhoda et al. (2015).
Location of water sources
The area of interest has two springs, which are natural groundwater outflow in the surface.
Groundwater resources
Aquifer in magmatic/metamorphic basement: moderate productivity
- magmatic rocks have low permeability
- Groundwater recharge is low
Ideal outcome: A possible groundwater source exists near the communities homes and borehole could be developed
Next steps to be taken with external actors
- Work with hydrogeologists to prepare a borehole siting report as well as an Environmental Impact Assessment. Groundwater relief has some trusted hydrogeologists in their network in Kenya who could implement that and submit the information to the Kenya Water Resources Agency.
- Kenya Water Resources Agency needs to grant permission for drilling.
- Drilling and pumping test: A contractor performs drilling and a pumping test. The latter is to identify the appropriate pump to be used.
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Groundwater level, type of aquifer, groundwater recharge, groundwater vulnerability.
Other solutions based on space technology and geophysics
Electromagnetic and seismic solutions
Barasa, M., Crane, E., Upton, K., Ó Dochartaigh, B.É. & Bellwood-Howard, I. (2018): Africa Groundwater Atlas: Hydrogeology of Kenya. British Geological Survey. Accessed [22.09.2023]. http://earthwise.bgs.ac.uk/index.php/Hydrogeology_of_Kenya
Kuria, Z. (2013): Groundwater Distribution and Aquifer Characteristics in Kenya. Developments in Earth Surface Processes, Elsevier. 16, 8, p. 83-107.
Krhoda, G., Nyandega, I. & Amimo, M. (2015): Geophysical investigations of Suyien Earthdam in Maralal, Samburu County, Kenya. International Journal of Physical Sciences. 2, p.33-49.
Makinouchi, T., Koyaguchi, T., Matsuda, T., Mitsushio, H. & Ishida, S. (1984): GEOLOGY OF THE NACHOLA AREA AND THE SAMBURU HILLS, WEST OF BARAGOI, NORTHERN KENYA. African Study Monographs, Supplementary Issue 2, p. 15-44.
Touber, L. (1986): Landforms and solid of samburu District, Kenya. A site evaluation for rangeland use. The Winand Staring Centre for Integrated Land, Soil and Water Research. Report 6.
Data sources (maps)
National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/national-atlas-kenya-geological-map (visited: 19.10.2021).
Samburu District - Type and Location of Water Sources, Key Landforms, and Soils (Symbols - See Map 11). (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/samburu-district-type-and-location-water-sources-key-landforms-and-soils-symbols-see-map-11 (visited: 19.10.2021)
