Integrating geological, hydrogeological and geophysical data to identify groundwater resources in granitic basement areas (Guéra Massif, Chad)

Integrating geological, hydrogeological and geophysical data to identify groundwater resources in granitic basement areas (Guéra Massif, Chad)

In Chad, hard-rock aquifers are the main source of drinking water for the population located on basement areas. In these basement aquifers, and in particular those of the Guéra region, water drilling failure rates remain high despite research on one- and two-dimensional electrical resistivity techni...

Full description

Saved in:
Bibliographic Details
Published in:Hydrogeology journal Vol. 32; no. 3; pp. 759 - 784
Main Authors: Nouradine, H., Schamper, C., Valdes, D., Moussa, I., Ramel, D., Plagnes, V.
Format: Journal Article
Language:English
Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2024
Springer Nature B.V
Subjects:
Aquatic Pollution
Aquifer systems
Aquifers
Basements
Biotite
Boreholes
Datasets
Drainage
Drainage patterns
Drilling
Drinking water
Dry wells
Earth and Environmental Science
Earth Sciences
Electrical resistivity
Flow rates
Fractures
Geology
Geomorphology
Geophysical data
Geophysics
Geophysics/Geodesy
Granite
Groundwater
Groundwater data
Groundwater resources
Horizon
Hydrogeology
Hydrology/Water Resources
Massifs
Overburden
Tomography
Waste Water Technology
Water Management
Water Pollution Control
Water Quality/Water Pollution
Water resources
Hard-rock aquifers
Electrical resistivity tomography
Geology
Well productivity
CHAD
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In Chad, hard-rock aquifers are the main source of drinking water for the population located on basement areas. In these basement aquifers, and in particular those of the Guéra region, water drilling failure rates remain high despite research on one- and two-dimensional electrical resistivity techniques and lineaments as a means to improve access to the resource, mainly because these techniques are only used on an observational and structural basis to locate fractures. This study combines electrical resistivity tomography (ERT) with geology, hydrogeology and geomorphology, in order to characterise the structure and geometry of the aquifer system, assess borehole productivity and determine the factors controlling it. After validating the large dataset and its representativeness, 315 high- and low-yield wells, of which 41 have complete geophysical datasets, were selected. This large dataset allows a multi-parameter approach to (1) better characterise each facies according to its electrical resistivity and (2) clearly identify the main formations constituting the local conceptual hydrogeological model. The most suitable areas for productive boreholes are characterised by the presence of an overburden of <20 m depth, well-developed weathered and fractured horizons of granites and biotite granites (preferably) containing little or no clay, and a nearby drainage network. The most substantial flow rates are found in the first 30 m of the fissured horizon, below the base of the alterites. The experience gained from the present study will guide future analysis of ERT sections in order to reduce the probability of drilling dry wells.
ISSN:1431-2174
1435-0157
DOI:10.1007/s10040-024-02766-2