Back
 JWARP  Vol.8 No.13 , December 2016
Modeling for Inter-Basin Groundwater Transfer Identification: The Case of Upper Rift Valley Lakes and Awash River Basins of Ethiopia
Abstract: Groundwater movement beneath watershed divide is one component of the hydrological cycle that is typically ignored due to difficulty in analysis. Numerical ground-water models, like TAGSAC, have been used extensively for predicting aquifer responses to external stresses. In this paper TAGSAC code was developed to identify the inter-basin groundwater transfer (IBGWT) between upper Awash River basin (UARB) and upper rift valley lakes basin (URVLB) of Ethiopia. For the identification three steady state groundwater models (for UARB, URVLB and for the two combined basins) were first created and calibrated for the 926 inventoried wells. The first two models are conceptualized by considering the watershed divide between the two basins as no-flow. The third model avoids the surface water divide which justifies IBGWT. The calibration of these three models was made by changing the recharge and hydrogeologic parameters of the basins. The goodness of fit indicators (GoFIs) obtained was better for the combined model than the model that describes the URVLB. Furthermore, the hydraulic head distribution obtained from the combined model clearly indicates that there is a groundwater flow that doesn’t respect the surface water divide. The most obvious effect of IBGWT observed in these two basins is that it diminishes surface water discharge from URVLB, and enhances discharge in the UARB. Moreover, the result of this study indicates potential for internal and cross contamination of the two adjacent groundwater.
Cite this paper: Mohammed, M. , Ayalew, B. (2016) Modeling for Inter-Basin Groundwater Transfer Identification: The Case of Upper Rift Valley Lakes and Awash River Basins of Ethiopia. Journal of Water Resource and Protection, 8, 1222-1237. doi: 10.4236/jwarp.2016.813094.
References

[1]   Atnafu, Y. and Mohammed, M. (2014) Characterization of Lake Water Groundwater Interaction in Hawassa Basin. Unpublished MSc. Thesis, AAU, AAiT.

[2]   Ayenew, T. (2001) Numerical Groundwater Flow Modelling of the Central Main Ethiopian Rift Lakes Basin. SINET: Ethiopian Journal of Science, 24, 167-184.

[3]   Awulachew, S.B., Yilma, A.D., Loulseged, M., Loiskandl, W., Ayana, M. and Alamirew, T. (2007) Water Resources and Irrigation Development in Ethiopia. Colombo, Sri Lanka. Working Paper 123, International Water Management Institute, 78 p.

[4]   Daniel, G. (1977) Aspects of Climate and Water Budget in Ethiopia. Technical Monograph, Addis Ababa University Press, Addis Ababa.

[5]   Lemma, G. (1996) Climate Classification of Ethiopia. Meteorological Research Report Series No. 3, National Meteorological Services Agency of Ethiopia, Addis Ababa.

[6]   Barnett, B., Townley, L.R., Post, V., Evans, R.E., Hunt, R.J., Peeters, L., Richardson, S., Werner, A.D., Knapton, A. and Boronkay, A. (2012) Australian Groundwater Modeling Guidelines. National Water Commission, Canberra.

[7]   USACE (U.S. Army Corps of Engineers) (1999) Engineering and Design Groundwater Hydrology, Washington DC.

[8]   Moore, J.E. (2002) Field Hydrogeology a Guide for Site Investigations and Report Preparation. Lewis Publishers, CRC Press LLC.
https://doi.org/10.1201/9781420032253

[9]   Ragunath, H.M. (2006) Hydrology, Principles Analysis Design. New Age International (P) Limited, New Delhi.

[10]   Ayenew, T., Kebede, S. and Alemyahu, T. (2008) Environmental Isotopes and Hydrochemical Study Applied to Surface Water and Groundwater Interaction in the Awash. Hydrological Processes, 22, 1548-1563.
https://doi.org/10.1002/hyp.6716

[11]   Karimi, P. (2014) Spatial Evapotranspiration, Rainfall and Land Use Data in Water Accounting—Part 2: Reliability of Water Accounting Results for Policy Decisions in the Awash Basin. Hydrology and Earth System Sciences Discussions, 11, 1-44.

[12]   Ayenew, T. (2007) The Distribution and Hydrogeological Controls of fluoride in the Groundwater of Central Ethiopian Rift and Adjacent Highlands. Environmental Geology, 54, 1313-1324.
https://doi.org/10.1007/s00254-007-0914-4

[13]   Long, J.C.S., Remer, J.S., Wilson, C.R. and Witherspoon, P.A. (1982) Porous-Media Equivalents for Networks of Discontinuous Fractures. Water Resources Research, 18, 645-658.
https://doi.org/10.1029/WR018i003p00645

[14]   Konikow and Reilly (1998) Groundwater Modeling. In: Dellure, J.W., Ed., The Hand Book of Groundwater Engineering, CRC press, Boca Raton, 20:1-20:40.
https://doi.org/10.1201/9781420048582.ch20

[15]   Fitts, C.R. (2002) Groundwater Science. Academic Press.

[16]   Praveena, S.M., Abdullah, M.H., Aris, A.Z. and Bidin, K. (2010) Groundwater Solution Techniques: Environmental Applications. Journal of Water Resource and Protection, 2, 8-13.
https://doi.org/10.4236/jwarp.2010.21002

[17]   Mohammed, M., Watanabe, K. and Takeuchi, S. (2010) Grey Model for Prediction of Pore Pressure Change. Environmental Earth Sciences, 60, 1523-1534.
https://doi.org/10.1007/s12665-009-0287-y

[18]   Anderson, M.P. and Woessner, W.W. (1992) Applied Ground Water Modeling: Simulation of Flow and Advective Transport. Academic Press, 1-143, 295-314.

 
 
Top