Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi
Study Region: Mkonga village, ∼35 km southwest of the capital city of Lilongwe on the central plains in Malawi, Africa, located at the crest of a local topographic-high characterized by crystalline basement. Study Focus: Groundwater aquifer systems in the shallow buried crystalline basement are geol...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-06-01
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| Series: | Journal of Hydrology: Regional Studies |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214581823001209 |
| _version_ | 1797801800752955392 |
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| author | Leonard O. Ohenhen Micah Mayle Folarin Kolawole Ahmed Ismail Estella A. Atekwana |
| author_facet | Leonard O. Ohenhen Micah Mayle Folarin Kolawole Ahmed Ismail Estella A. Atekwana |
| author_sort | Leonard O. Ohenhen |
| collection | DOAJ |
| description | Study Region: Mkonga village, ∼35 km southwest of the capital city of Lilongwe on the central plains in Malawi, Africa, located at the crest of a local topographic-high characterized by crystalline basement. Study Focus: Groundwater aquifer systems in the shallow buried crystalline basement are geologically complex reservoir targets with historically low drilling success rates. Understanding the basement weathering profiles and their implications for aquifer architecture is crucial for drilling productive wells. This is particularly critical in developing countries where water demands are rising. This study employs an integrated approach of 2-D seismic reflection and 2-D electrical resistivity imaging, constrained by borehole data to characterize the local basement aquifers in the crystalline-dominated terranes of central Malawi. New Hydrological Insights for the Region: The integrated geophysical and borehole data reveal a layered weathering profile: shallow thin laterite and sub-lateritic layers, the saprolite, the saprock, and the fractured/fresh basement. We identify four potential water-bearing zones consisting of the base of the sub-laterite layer, the saprolite, the saprock and the fractured basement. The most productive boreholes are those that intersect low resistivity anomalies (< 20 ohm-m) that are collocated with strong but discontinuous reflectors. These targets are interpreted to represent water-bearing zones that connect the saprolite and saprock to recharge pathways at the base of the sub-laterite. |
| first_indexed | 2024-03-13T04:56:00Z |
| format | Article |
| id | doaj.art-d2c50d9931e34d30b5d40216303df2c8 |
| institution | Directory Open Access Journal |
| issn | 2214-5818 |
| language | English |
| last_indexed | 2024-03-13T04:56:00Z |
| publishDate | 2023-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Hydrology: Regional Studies |
| spelling | doaj.art-d2c50d9931e34d30b5d40216303df2c82023-06-18T05:02:05ZengElsevierJournal of Hydrology: Regional Studies2214-58182023-06-0147101433Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central MalawiLeonard O. Ohenhen0Micah Mayle1Folarin Kolawole2Ahmed Ismail3Estella A. Atekwana4Department of Geosciences, Virginia Tech., Blacksburg, VA, USA; Virginia Tech National Security Institute, Blacksburg, VA, USADepartment of Geosciences, Colorado State University, Fort Collins, CO, USADepartment of Earth & Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USABoone Pickens School of Geology, Oklahoma State University, Stillwater, OK, USADepartment of Earth and Planetary Sciences, University of California, Davis, Davis, CA, USA; Corresponding author.Study Region: Mkonga village, ∼35 km southwest of the capital city of Lilongwe on the central plains in Malawi, Africa, located at the crest of a local topographic-high characterized by crystalline basement. Study Focus: Groundwater aquifer systems in the shallow buried crystalline basement are geologically complex reservoir targets with historically low drilling success rates. Understanding the basement weathering profiles and their implications for aquifer architecture is crucial for drilling productive wells. This is particularly critical in developing countries where water demands are rising. This study employs an integrated approach of 2-D seismic reflection and 2-D electrical resistivity imaging, constrained by borehole data to characterize the local basement aquifers in the crystalline-dominated terranes of central Malawi. New Hydrological Insights for the Region: The integrated geophysical and borehole data reveal a layered weathering profile: shallow thin laterite and sub-lateritic layers, the saprolite, the saprock, and the fractured/fresh basement. We identify four potential water-bearing zones consisting of the base of the sub-laterite layer, the saprolite, the saprock and the fractured basement. The most productive boreholes are those that intersect low resistivity anomalies (< 20 ohm-m) that are collocated with strong but discontinuous reflectors. These targets are interpreted to represent water-bearing zones that connect the saprolite and saprock to recharge pathways at the base of the sub-laterite.http://www.sciencedirect.com/science/article/pii/S2214581823001209Basement aquifersElectrical resistivity imaging (ERI)Seismic reflectionSaproliteSaprockFractured basement |
| spellingShingle | Leonard O. Ohenhen Micah Mayle Folarin Kolawole Ahmed Ismail Estella A. Atekwana Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi Journal of Hydrology: Regional Studies Basement aquifers Electrical resistivity imaging (ERI) Seismic reflection Saprolite Saprock Fractured basement |
| title | Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi |
| title_full | Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi |
| title_fullStr | Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi |
| title_full_unstemmed | Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi |
| title_short | Exploring for groundwater in sub-Saharan Africa: Insights from integrated geophysical characterization of a weathered basement aquifer system, central Malawi |
| title_sort | exploring for groundwater in sub saharan africa insights from integrated geophysical characterization of a weathered basement aquifer system central malawi |
| topic | Basement aquifers Electrical resistivity imaging (ERI) Seismic reflection Saprolite Saprock Fractured basement |
| url | http://www.sciencedirect.com/science/article/pii/S2214581823001209 |
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