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HYDROGEOLOGICAL CHARACTERISTIC OF AQUIFERS
AND
BOREHOLE PERFORMANCE ASSESSMENT
FOR RURAL WATER SUPPLY IN SOUTHERN PART OF
STATE KADUNA, NW NIGERIA
6th Rural Water Supply Network Forum 2011 Uganda
Dr. M.O. Eduvie Rural Water Supply and Sanitation Centre,
National Water Resources Institute
Kaduna Nigeria
Dr. J.A. Otun Dept. of Water Resources Engineering,
Ahmadu Bello University Zaria
Nigeria
Introduction • The importance of groundwater as a water supply
source to the socioeconomic development of any
nation is tremendous
– GW is the only viable source of water in many remote
villages where development of surface water is not
economically viable.
• Some difficulties experienced in its exploration and
exploitation in the basement areas where aquifers
are both isolated and compartmentalized
• Exploration programme now requires the use of
multi-disciplinary approach involving, geological and
hydro-geological mapping, geophysical
investigations.
6th Rural Water Supply Network Forum 2011 Uganda
Study Approach
• Conceptually, locating productive boreholes in
areas with inadequate hydrogeological
information is usually difficult and very tasking.
• A multidisciplinary approach was used to study
and characterize the aquifer parameters and
evaluate the groundwater potentials of the
crystalline basement of the study area in Kaduna
State.
6th Rural Water Supply Network Forum 2011 Uganda
Multi-Disciplinary Approach • Preliminary hydrogeological assessment:
– Used to describe and understand the salient
hydrogeological features of its dominant rock types
• Hydrological review
– as it affects the groundwater availability,
– in addition to surface geophysical surveys (using the
electromagnetic (EM) and resistivity techniques), well
water level measurements, borehole drilling and pumping
tests and water quality analysis that were carried out.
• Spatial Mapping and Interpretations: Mapping of obtained superimposed data to produce several hydro-
geological maps that are best considered to be valuable for
interpretation and management of the entire ground water resources
of the study area.
6th Rural Water Supply Network Forum 2011 Uganda
Assessment of Hydrogeological Characteristics:
• Geological and Hydrogeological Mapping:
Set of hydrogroundwater configuration maps
were constructed by the superimposition method
and the corresponding hydrogeological cross
section drawn.
• Geophysical survey: Electromagnetic (EM)
method used for some traversing, the resistivity
method using Wenner array was also employed.
– Vertical electrical soundings were conducted in
promising zones identified after profiling
6th Rural Water Supply Network Forum 2011 Uganda
Geological and structural map of the study area
6th Rural Water Supply Network Forum 2011 Uganda
Groundwater Configuration Map of the study area
6th Rural Water Supply Network Forum 2011 Uganda
Hydrological cross section of NE-SW line
6th Rural Water Supply Network Forum 2011 Uganda
Geophysical Investigations: Typical EM responses in the study
area
6th Rural Water Supply Network Forum 2011 Uganda
Findings
6th Rural Water Supply Network Forum 2011 Uganda
• Two geophysical survey techniques employed
proved effective in determining the regolith aquifers
in terms of thickness of water saturated zone with
subsurface layering ranging from 3-5 layers.
• Characterization of borehole parameters within the
study area :
– Borehole yields (7.2-302.4 m3/day),
– Aquifer transmissivity (0.359-101 m2/day) and
– Hydraulic conductivity (0.03 -10.9m/day)
• Obtained database helped in constructing hydro-
geological maps
Conclusions
6th Rural Water Supply Network Forum 2011 Uganda
• The study through its multi-disciplinary
approach showed the high groundwater
potentials of the basement complex area of
Southern parts of Kaduna State of Nigeria.
• It derives quantum of hydrogeological
information databases which were non-
available before the study:
– Preparation of hydrogeological maps
– Borehole logging database,
– Water quality analysis and database,
– Well reviews and pre-drilling geophysical investigations;
Conclusions
6th Rural Water Supply Network Forum 2011 Uganda
• With the quantum of hydrogeological
information databases derived from several
multi-disciplinary analysis carried out the
entire groundwater resources in the study
area is certainly poised and optimised for
effective rural water supply;
• Understanding these hydrogeological
characteristics of the weathered/fractured
aquifers in this study area is essential for
sound borehole design, construction and
management.
• ,