Groundwater Vulnerability Assessment of the Tarkwa Mining Area Using SINTACS Approach and GIS


  • Anthony Ewusi Geological Engineering Department University of Mines and Technology Tarkwa
  • Isaac Ahenkorah Geological Engineering Department, UMaT
  • J. S. Y. Kuma Geological Engineering Department, UMaT


Groundwater. Vulnerability. Tarkwa. SINTACS. GIS.


Groundwater vulnerability assessment to delineate areas that are susceptible to contamination from mining and anthropogenic activities has become an important element for resource management and landuse planning. In view of the extensive mining in the Tarkwa area, quality of groundwater has become an important issue. This study estimates aquifer vulnerability by applying the SINTACS model which uses seven environmental parameters to evaluate aquifer vulnerability and geographical information system (GIS) in the Tarkwa mining area. Sensitivity analysis has also been carried out to evaluate the relative importance of the model parameters for aquifer vulnerability. The SINTACS model results show that the intrusive rocks within the Tarkwaian and the Birimian rocks are dominated by very high vulnerability classes while the Banket Series is characterised by high vulnerability class. The Huni Sandstones have moderately high vulnerability. In addition, the Kawere Group and the Tarkwa Phyllites displayed medium vulnerability. Analysis from the variogram model shows that all parameters used in the SINTACS model have a strong spatial structure. From statistical analysis, depth to water parameter inflicted the highest impact on the vulnerability of the aquifer followed by effective infiltration, vadose zone media, soil media, aquifer media, topography and hydraulic conductivity in the order of decreasing impact. Sensitivity analysis indicated that the aquifer media, hydraulic characteristics and topography cause large variation in vulnerability index. Depth to water and effective infiltration were found to be more effective in assessing aquifer vulnerability.

Keywords: Groundwater, Vulnerability, Tarkwa, SINTACS, GIS

Author Biography

Anthony Ewusi, Geological Engineering Department University of Mines and Technology Tarkwa

Senior Lecturer


Akabza, T. M. (2000), “The Environmental and Social Impacts of Mining in the Wassa West District of Ghanaâ€, Third World Network-Africa, pp. 17-22.

Akabzaa, T. and Darimani, A. (2001), Impact of mining sector investment in Ghana, A study of the tarkwa mining region, 52 pp.

Anon. (2010), “Mining operations violate right of mining communities to clean water- Wacamâ€, /wap/article.php?ID=178917. Accessed: February 10, 2016.

Anon. (1991),“VariogramTutorial.GoldenSoft.Incâ€, Accessed: February28, 2017.

Baldridge, E. (2004), Developing Spatially Interpolated Surfaces and Estimating Uncertainty. U.S. Environmental Protection Agency, Office of Air and Radiation, Office of Air Quality Planning and Standards.

Cività , M. and De Maio, M. (1997), “SINTACS: Un sistema parametrico per la valutazione e la cartografia della vulnerabilita degli acquiferi all’inquinamentoâ€, Metodologia & automatizzazione. Bologna, Pitagora Editrice, 208 pp.

Eisenlohr, B. N. and Hirdes, W. (1992), “The structural development of the early Proterozoic Birimian and Tarkwaian rocks of South west Ghana, West Africaâ€, Journal of African Earth Sciences, Vol. 14, No. 3, pp. 313-325.

Fetter, C. W. (1994), Applied Hydrogeology, 2nd edition, Macmillan College Publishing Company, New York, NY, 615 pp.

Junner, N. R., Hirst, T. and Service, H. (1942), “The Tarkwa Goldfieldâ€. Gold Coast Geological Survey, Memoir, No. 6, pp. 48-55.

Kesse, G. O. (1985), The Mineral and Rock Resources of Ghana, A. A. Balkema Publishers, Rotterdam, 610 pp.

Kortatsi, B. K. (2002), “Hydrochemistry of groundwater in the mining area of Tarwa- Prestea, Ghanaâ€, Ph.D. Thesis, University of Ghana, pp. 70-85.

Kuma, J. S. (2007), “Hydrogeological studies in the Tarkwa Gold Mining District, Ghanaâ€, Bulletin of Engineering Geology and the Environment 66, pp. 89 - 99.

Kuma, J. S. and Younger, P. L. (2001), “Pedological characteristics related to groundwater occurrence in the Tarkwa area, Ghanaâ€, J. Afr. Earth Sci., Vol. 3, No. 33, pp. 363-376.

Naicker, K., Cukrowska, E. and McCarthy, T. S. (2003), Acid mine drainage arising from gold mining activity in Johannesburg, South Africa and environs, Vol. 122, pp. 29–40.

Smedley, P. L., Edmunds, W. M., West, J. M., Gardner, S. J. and Pelig K. B. (1995), “Vulnerability of Shallow Groundwater Quality due to Natural Geochemical Environment.â€, Report prepared for ODA under the ODA/BGS Technology Development and Research Programme. Project 92/5.

Tazioli, G. S., Cantori, P. M. and Ciancetti, G. F. (1995), “Inter-comparison of different tracers in the evaluation of groundwater dynamics in heterogeneous porous aquifersâ€, IAEA-SM 336/40, Vienna, 147 pp.

Yankey, R. K., Akiti, T. T., Osae, S., Fianko, J. R., Duncan, A. E., Amartey, E. O., Essuman, D. K. and Agyemang, O. (2011), “Research Journal of Environmental and Earth Sciencesâ€, Vol. 3, No. 5, pp. 600-607.






Geological Eng. Article