In a new open paper in the Hydrogeological Journal, Dr Fabio Fussi and his UPGro Catalyst team present work done in Senegal that looks at how improving hydrogeological data, maps and understanding can improve the success of manually drilled boreholes.
In a region where access to safe, affordable water is limited, manual drilling provides a cost-effective way of tapping groundwater resources. However, aquifers are complex and striking fresh water is not guaranteed.
Fussi and his team propose a model that uses analysis of borehole logs for the to characterise shallow aquifers so that areas suitable for manual drilling can be found. The model is based on available borehole-log parameters: depth to hard rock, depth to water, thickness of laterite (a iron-rich rock type common in the tropics) and hydraulic properties of the shallow aquifer. The model was applied to a study area in northwestern Senegal.
The hydraulic conductivity values – how easily water flows through rock – were estimated from geological data and partially validated by comparing them with measured values from a series of pumping tests carried out in large-diameter wells.
The results show that this method is able to produce a reliable interpretation of the shallow hydrogeological context using information generally available in the region.
The research contributes to improving the identification of areas where conditions are suitable for manual drilling, and has the potential to be used throughout Africa, and beyond, using data available in most African countries.
Ultimately, this work will support proposed international programs aimed at promoting low-cost water supply in Africa and enhancing access to safe drinking water for the population.