Seasonal Assessment of Aquifer Vulnerability to Pollution in Garoua-Cameroon using the D.R.A.S.T.I.C Model

Eyong Thomson Areakpoh^1, , Akoachere Richard Ayuk II², Omogbemi Omoloju Yaya³ and Ntonga Jean Claude¹

¹Hydrological Research Center, P.O.Box: 4110 Yaounde

²Department of Geology, University of Buea, Buea, Cameroon

³National Water Resources Institute, Kaduna, Nigeria

Cite this paper

Eyong Thomson Areakpoh, Akoachere Richard Ayuk II, Omogbemi Omoloju Yaya and Ntonga Jean Claude. Seasonal Assessment of Aquifer Vulnerability to Pollution in Garoua-Cameroon using the D.R.A.S.T.I.C Model. American Journal of Water Resources. 2024; 12(1):12-23. doi: 10.12691/AJWR-12-1-2

Abstract

Aquifers are the main sources of water in Garoua and due to a lack of knowledge of their vulnerability to contaminants for the management and protection of these aquifers, this study to assess their vulnerability to pollution within four hydrogeological seasons using the DRASTIC (Depth-to-water, net-Recharge, Aquifer-media, Soil-media, Topography, Impact-of-vadose-zones and hydraulic-Conductivity) model was a necessity. Depth to water (D) of 196 wells ranged from 0.2 to 11.87 m are assigned ratings of 5, 7, 9 and 10. Net Recharge (R) ranged between 0-35.4 mm/yr. with assigned rating of 1. Aquifer media (A) are alluvium, sandstone, granites, and gneiss with ratings of 10, 8, 10 and 7. Soil media (S) from 50 infiltrometer tests are sands, silty clay, clays and loam soils with assigned ratings of 1, 5, 7 and 10. Topographic (T) slopes from DEMs varied from 0% to 18% were classed into 7 ranges and assigned ratings of 1, 3, 5, 7, 8, 9 and 10. Impact of the vadose zone of sand, clay and gravel were assigned ratings of 3, 9 and 10. Hydraulic conductivity (C) from slug tests on 50 wells ranged from 0.12 to 0.7 m/day and was assigned rating of 1. The derivative DRASTIC scores of aquifer vulnerability to contaminants in Garoua were: 150 in the wet season, 146 in wet-dry season, 158 in dry season and 157 in dry-wet season. DRASTIC indices classified the area into a high vulnerability class in all seasons. These higher vulnerabilities to pollution could be due to porous sandstone formations, the presence of fractured gneisses and fractured granites. From single parameter sensitivity analysis, depth to water, aquifer media, topography and impact of the vadose zone layer tend to be the most effective parameters in the vulnerability assessment because their mean effective weights are higher than their theoretical weights. Highest vulnerabilities to pollution occur during the dry seasons; this is of particular importance since during these periods water is scarce thereby, decreasing the pollution opportunity as there is no transport medium into the aquiferous formations.

Keywords

Aquifer-vulnerability, Drastic-model, Groundwater-Pollution, Garoua-Cameroon

Copyright

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References

[1]	Rahman, A. A GIS based DRASTIC model for assessing groundwater vulnerability in shallow aquifer in Aligarh, India. Appl. Geograp. 28 (2008), 32–53, 2008.
[2]	Babiker, I.S., Mohamed, M.A.A., Hiyanna, T., and Kato, A. A GIS Based DRASTIC Model for Assessing Aquifer Vulnerability in Kakamigahara Heights, Gifu Prefecture, Central Japan. Science of the Total Environment, 345, 127-140, 2005.
[3]	Jawed, I., Gorai, A.K., Poonam, T., and Gopal, P. Approaches to groundwater vulnerability to pollution: a literature review. Asian Journal of Water, Environment and Pollution 9 (1), 105–115, 2012.
[4]	Leone, A., Ripa, M.N., Uricchio, V., Deak, J., and Vargay, Z. Vulnerability and risk evaluation of agricultural nitrogen pollution for Hungary’s main aquifer using DRASTIC and GLEAMS models. J. Environ. Manage. 90, 2969–2978, 2009.
[5]	Yin, L., Zhang, E., Wang, X., Wenninger, J., Dong, J., Guo, L., and Huang, J. AGIS-based DRASTIC model for assessing groundwater vulnerability in the Ordos Plateau, China. Environ Earth Sci 69: 171–185, 2013.
[6]	Akenji, V.N., Ako, A.A., Akoachere, R.A., and Hosono, T. DRASTIC-GIS Model for Assessing Vulnerability to Pollution of the Phreatic Aquiferous Formations in Douala-Cameroon. Journal of African Earth Science, 102, 180-190, 2015.
[7]	Njitchoua, R., and Ngounou-Ngatcha, B. Hydrogeochemistry and environmental isotopes investigations of the north Diamare plain northern Cameroon. J Afr Earth Sci, 25:307-316, 1997.
[8]	Moïse, B., ., John, T.E., , , , , , , , , and Hydrocarbon potential, palynology and palynofacies of four sedimentary basins in the Benue Trough, northern Cameroon , Pages 73-95, 2018.
[9]	Guiraud, R., and Maurin, J. Early Cretaceous rifts of Western and Central Africa: an overview. In: Ziegler PA. Ed. Geodynamics of Rifting, Volume II. Case history studies on rifts: North and South America and Africa. Tectonophysics.; 21 3: 1 53-1 68, 1992.
[10]	Eyike, A., Werner, S.C., Ebbing, J.E., and Dicoum, M. On the use of global potential field models for regional interpretation of the West and Central African Rift System. Tectonophysics, 2010.
[11]	Serge, H., Kengni, P., Tabod, ., , , Depth Variation of the Lithosphere beneath Garoua Rift Region (Cameroon Volcanic Line) Studied from Teleseismic P-Waves , 2019.
[12]	Njitchoua, , Dever, , Ch.Fontes , and Naah, Geochemistry, origin and recharge mechanisms of groundwater from the Garoua Sandstone aquifer, northen Cameroon , Pages 123-140, 1997.
[13]	Kamguia, J., Manguelle-Dicoum, Tabod, ., and Tadjou, Geological models deduced from gravity data in the Garoua basin, Cameroon Journal of Geophysics and Engineering, Volume 2, Issue 2, Pages 147–152, 2005.
[14]	Poudjom, D.Y.H., Diament, M., and Albouy, Y. 1992. Mechanical behaviour of the lithosphere beneath the Adamawa Uplift (Cameroon, West Africa) based on gravity data. J. Afr. Earth Sci., 15: 81–90.
[15]	Mouzong, M.P., Kamguia, J., Nguiya, S., Shandin,i Y., and Manguelle-Dicoum, E. Geometrical and structural characterization of Garoua sedimentary basin, Benue Trough, North Cameroon, using gravity data. J Biol Earth Sci 201 4 4(1):E25–E33, 2014.
[16]	Parisa, A., Seiyed, M.H., and BehzadAtaie-Ashtiani, C.T.S. Fuzzy vulnerability mapping of urban groundwater systems to nitrate contamination , Pages 146-157, 2017.
[17]	Aller, L., Bennett, T., Lehr, J.H., Petty, R.J., and Hackett, G. DRASTIC: A standardized system for evaluating groundwater pollution potential using hydrogeologic settings, Environmental Protection Agency Report, NWWA/EPA Series EPA-600/ 2-87-035, 1987.
[18]	Hillel, D. Fundamentals of soil physics. New York: Academic Press Inc, 1980.
[19]	Akoachere, R.A., and Ngwese, Y.M. Saturated Hydraulic Conductivities and High Yield Zones in the Phreatic Auriferous Formations in Kumba – Cameroon: Determined From Slug-In Tests in Dug Wells. J Hydrogeol Hydrol Eng 5:4, 2016.
[20]	Insaf, S., Mohamed, A., Tetsuya, H., Kikuo, K., 2005. A GIS-based DRASTIC model for assessing aquifer vulnerability in Kakamigahara Heights, Gifu Prefecture, central Japan. Sci. Total Environ. 345, 127–140.
[21]	Merchant, J.W. GIS-based groundwater pollution hazard assessment a critical review of the DRASTIC model. Photogramm. Eng. Remote Sens. 60 (9), 1117– 1127, 1994.
[22]	Khabat, K., Majid, S., Mahshid, K., Jana, L., and Aghdas, L.. A GIS-based groundwater pollution potential using DRASTIC, modified DRASTIC, and bivarite statistical models Environmental Science and Pollution Reaserch (2021) 28: 50525-50541, 2021
[23]	Lodwik, W.A., Monson, W., and Svoboda, L. Attribute error and sensitivity analysis of maps operation in geographical information systems–suitability analysis. Int. J. Geograph. Inform. Syst. 4, 413–428, 1990.
[24]	Bazimenyera, D., and Zhnoghua, T. A GIS based DRASTIC model for assessing groundwater vulnerability in shallow aquifer in Hangzhou–Jiaxing–Huzhou Plain. China Research Journal of Applied Sciences 3(8):550–559. Medwell Journals, 2008.
[25]	Amit, G., and A GIS based DRASTIC model for assessing groundwater vulnerability of Katri Watershed, Dhanbad, India volume 1, Article number: 11 (2015).
[26]	Brindha, K., and , L. Cross comparison of five popular groundwater pollution vulnerability index approaches , Pages 597-613, 2015.
[27]	Jacques, É.D., Jean, K.K., Kouakou, S.D., Amani T.A., and Jean P.J. Contribution of the Sensitivity Analysis in Groundwater Vulnerability Assessing Using the DRASTIC Method: Application to Groundwater in Dabou Region (Southern of Côte d’Ivoire) 07(01): 2016.
[28]	Kourosh, M., Ramin N., Vahid, J., and Majd, Aquifer vulnerability assessment using GIS and fuzzy system:a case study in Tehran–Karaj aquifer, Iran Environ Geol (2009) 58: 437–446, 2008.
[29]	Ziad, A.M., and Modified DRASTIC assessment for intrinsic vulnerability mapping of karst aquifers: a case study volume 66, pages447–456, 2012.
[30]	Voudouris, K., Kawakis, N., Polemio, M., and Karelas, K.. Assessment of intrinsic vulnerability using DRASTIC model and GIS in the Kiti aquifer, Cyprus. Eur. Water 30, 13–24, 2010
[31]	Muhammad, U., , , , ., , , , , ., and A modified approach to quantify aquifer vulnerability to pollution towards sustainable groundwater management in Irrigated Indus Basin Environ Sci Pollut Res Int; 29(18): 27257-27278.
[32]	Mohammed, M., and Majid, N. GIS – based DRASTIC and composite DRASTIC indices for assessing groundwater vulnerability in the Baghin Nat, Hazard syst. Scio,, 20, 2351-2363.
[33]	Fritch, T., McKnight, C., Yelderman, J., and Arnold, J. An aquifer vulnerability assessment of the paluxy aquifer, central Texas, USA, using GIS and a modified DRASTIC approach. Environ. Manage. (25), 337–345, 2000.
[34]	Kouamé, K.I., Douagui, G.A., Koffi, K., Dibi, B., and Kouassi, K.K. Modeling of Quaternary Groundwater Pollution Risk by GIS and Multicriteria Analysis in the Southern District Share of Abidjan (Ivory Coast). Journal of Environmental Protection, 4, 1213-1223, 2013.
[35]	Doumouya, I., Dibi, B., Kouame, I.K., Saley, B., Jourda, J.P., Savane, I., and Biémi, J. Modeling of Favorable Zones for the Establishment of Water Points by Geographical Information System (GIS) and Multicriteria Analysis (MCA) in the Aboisso Area (South-East of Côte d’Ivoire). Environmental Earth Science, 67, 1763-1780, 2012.
[36]	Samake, M.H., Tang, Z., Hlaing, W., Ndoh, M.I, Kasereka, K., and Balogun, W. Groundwater Vulnerability Assessment in Shallow Aquifer in Linfen Basin, Shanxi Province, China Using DRASTIC Model. Journal of Sustainable Development, 4, 53-71, 2011.
[37]	El-Naqa, A., Hammouri, N., and Kuisi, M. -Based Evaluation of Groundwater Vulnerability in the Russeifa Area, Jordan. Revisita Mexicana de Ciencias Geológicas, 23, 277-287, 2006.