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
- QGIS: A Free and Open Source Geographic Information System. Version 3.32.3 / Version 3.28.11 LTR.
- ArcGIS Pro. Version ArcGIS Pro 3.
- 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
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.
- 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.
- 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. ---
- A desk study compares the geology with the topography
Location of water sources
The area of interest has two springs, which are natural groundwater outflow in the surface.
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.
Groundwater level, type of aquifer, groundwater recharge, groundwater vulnerability.
Other solutions based on space technology and geophysics
Electromagnetic and seismic solutions