Hydrogeoelectrical evaluation of groundwater flow pattern in a Basement Complex terrain, Southwest Nigeria

Hydrogeoelectrical evaluation of groundwater flow pattern in a Basement Complex terrain, Southwest Nigeria

Omowumi AdemilaBlessing Saloko 

Department of Earth Sciences, Adekunle Ajasin University, Akungba-Akoko, Nigeria

Corresponding Author Email: 
omowumi.ademila@aaua.edu.ng
Page: 
7-14
|
DOI: 
https://doi.org/10.18280/eesrj.050102
Received: 
28 January 2018
|
Accepted: 
07 February 2018
|
Published: 
31 March 2018
| Citation

OPEN ACCESS

Abstract: 

Heavy reliance on groundwater for potable water and increasing groundwater contamination from human activities in Supare Akoko has prompted this research work. The study examined the pattern of groundwater movement by combining hydrogeologic measurements and electrical resistivity survey in the area in order to identify the groundwater converging centres and to locate appropriate dumpsites. The hydrogeologic measurements involved static water levels measurement of 40 hand-dug wells while the electrical resistivity investigation involved a total of 40 geoelectric soundings using the Schlumberger electrode configuration. The results of the hydrogeologic measurements were presented as maps of 3-D surface elevation, static water elevation, groundwater head and groundwater vector. These maps revealed that groundwater flows from central, western and southeastern regions to the southwestern and northeastern parts of the area. Two types of aquifer, which are the weathered layer aquifer and weathered/fractured (unconfined) aquifer with resistivity values of 62 – 332 Ωm and 207 – 989 Ωm respectively, were delineated from the geoelectric parameters of the study area. Aquifer layer resistivity map revealed that groundwater flow directions are from the west and north into other parts of the area, towards the southwestern and northeastern parts. The values of the aquifer characteristics obtained were in the range of 2.88 – 437.4 m2/day for transmissivity, 1.2 – 40.5 m/day for hydraulic conductivity and 0.001 – 0.016 mS/m for electrical conductivity. The distribution of transmissivity values suggests the state of different aquifer systems in the area. These values when compared with international standards showed that the water in the aquifer is of high quality and yield from which long pumping can be maintained due to its capacity to regain water within a short period of time. A water scheme is proposed in the groundwater converging centres of the area to provide enough water for the people in the area. It is therefore recommended that dumpsites should be placed within the southern parts of the area in order to avert groundwater contamination. The inhabitants of the town must also be enlightened on the importance of ensuring a clean and hygienic environment around the source of their water to avoid associated health problems.

Keywords: 

hydrogeologic measurement, electrical resistivity, groundwater flow pattern, groundwater head, transmissivity, aquifer

1. Introduction
2. Description of the Study Area (Geology and Hydrogeology)
3. Materials and Methods
4. Determination of Aquifer Parameters from VES Results
5. Results and Discussion
6. Conclusion
  References

[1] Al-Garni MA, Hassanein H, Gobashy M. (2006). Geophysical investigation of     groundwater in Wadi lusab, Haddat ash sham area. Makkah al-mukarramah, Arab Gulf Journal of Scientific Research 24(2): 83-93.

[2] Anomohanran O. (2013). Geophysical investigation of groundwater potential in Ukelegbe, Nigeria. Journal of Applied Sciences 13: 119-125.

[3] Bhattacharya PK, Patra HP. (1968). Direct current geoelectric sounding, elsevier publishing company. Amsterdam, 135.

[4] Delleur JW. (1999). Handbook of Groundwater Engineering. In: J.W. Delleur (eds) Elementary Groundwater Flow and Transport Processes. 

[5] Fetter CW. (2007). Applied Hydrogeology, 2nd ed. C.B.S. Publishers and Distributors, New Delhi India, 550, pp. 161-201.

[6] Gaarg SK. (2003). Physical and Engineering Geology, 4th Edition. Khana Publishers, 2-B Market, Nai Sarak, Delhi, pp. 330-351.

[7] Kaya GK. (2001). Investigation of groundwater contamination using electric and electromagnetic methods at open waste-disposal site, a case study from Isparta. Turkey, Environmental Geology 40: 725-731.

[8] Keller GV, Frischknecht FC. (1966). Electrical method in geophysical prospecting. Pergamon Press. Oxford, p. 523.

[9] Koefoed O. (1979). Geosounding Principles 1. Resistivity sounding measurements. Elsevier Science Publishing Company, Amsterdam.

[10] Kossinski WK, Kelly WE. (1981). Geoelectric sounding for predicting aquifer properties. Groundwater 9(2): 163-171.

[11] Morrisson BL, Lawrence ARL, Chilton PJC, Adams B, Calow RC, Klinck BA. (2003). Groundwater and its susceptibility to degradation: A global assessment of the problem and options for management. Early Warning and Assessment Report Series, RS. 03–3. Nairobi, Kenya: United Nations Environment Programme, p. 126.

[12] Neilson DM. (1991). Groundwater Monitoring. Lewis Publishers, Chelsea, Michigan, p. 717.

[13] Nigeria Meteorological Agency, (NIMET). (2007). Daily weather forecast on the Nigerian Television Authority, Nigerian Metrological Agency. Oshodi, Lagos, Nigeria.

[14] Niwas S, Singhal DI. (1981). Estimation of aquifer transmissivity from Dar Zarouk parameters in porous media. Journal of Hydrology 50: 393-399.

[15] Rajasekhar P, Vimal KP, Mansoor M. (2014). Determination of confined aquifer parameters by Sushil k. Singh method. American International Journal of Research Science, Technology, Engineering and Mathematics 5: 158-163.

[16] Singhal BBS., Singhal DC. (1986). Evaluation of Aquifer Parameters and Well Characteristics in fractured rock formation on Karnataka India University of Rookee, Rookie India, 351-363.

[17] Tizro TA, Voudouris KS, Kamali M. (2014). Comparative study of step drawdown and constant discharge tests to determine the aquifer transmissivity: The Kangavar aquifer case study, Iran. Journal of Water Resources and Hydraulic Engineering 3: 12-21. 

[18] Troisi S, Fallicos C, Straface S, Migliari E. (2000). Application of kriging with external drift to estimate hydraulic conductivity from electrical resistivity data in unconsolidated deposits near Montato Uffugo, Italy. Hydrogeology Journal 8: 356-367.

[19] United States Environmental Protection Agency Drinking Water Standards and Health Advisories USEPA. Washington, DC. 2012. EPA 822-S-12-001.

[20] Vander Velper BPA. (2004). Win resist version 1.0 resistivity depth sounding interpretation software. MSc. Res Project, ITC, Delft Nether.