Is Climate Change affecting Transboundary Aquifers?

Following on from Scheumann and Alker’s (2009) argument mentioned in my 3^rd blogpost about decreasing precipitation contributing to low levels of groundwater in recent years, I’ve decided to explore this claim further.

As we all know, climate change is having a range of detrimental effects on countries around the world. We’re always hearing about melting icecaps and sea levels rising in the news, it seems we tend to forget about the effects it has on transboundary aquifers!

Carter and Parker (2009) estimate that half of Africa’s one billion people depend on groundwater for their daily water supply. Climate change is set to increase variability and quantity of rainfall and river flows, as well as the overall geographical distribution of water (Kundzewicz et al., 2007; Goulden, Conway and Persechino, 2009). With the recharging of TBAs largely dependent on rainfall and river flows, this will of course lead to the problem of likely lower discharge levels.

The last thing I’ll leave you with today is the table below which shows changes in temperature and precipitation levels between current and future stages (Christensen et al.,2007).

From this table we can clearly see that average annual and seasonal temperature change is forecasted in each sub-region, leading to warmer temperatures. Interestingly, it’s predicted that West and East Africa will become a wetter environment, whereas Southern Africa and the Sahara are likely to become drier. As a result of this, it is likely that higher temperatures will increase evaporation throughout Africa, leading to lower levels of surface and ground water. Similarly, the decreased levels of rainfall in Southern Africa and the Sahara will likely have damaging effects on the recharging capabilities of TBAs within these regions.

References:

Carter, R. C. & Parker, A. (2009) Climate change, population trends and groundwater in            Africa. Hydrol. Sci. J. 54(4), 676–689.

Christensen, J. H., Hewitson, B., Busuioc, A., Chen, A., Gao, X., Held, I., Jones, R., Kiolli, R.       K., Kwon, W.-T., Laprise, R., Magaña Rueda, V., Mearns, L., Menéndez, C. G., Räisänen, J., Rinke, A., Sarr, A. & Whetton, P. (2007) Regional climate projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the      Fourth Assessment Report of the Intergovernmental Panel on Climate Change (ed. By S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor & H.       L. Miller). Cambridge University Press, Cambridge, UK.

Kundzewicz, Z. W., Mata, L. J., Arnell, N. W., Döll, P., Kabat, P., Jiménez, B., Miller, K. A.,        Oki, T., Sen, Z. & Shiklomanov, I. (2007) Freshwater resources and their management.          In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of             Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on   Climate Change (ed. by M. L. Parry, O. F. Canziani, J. P. Palutikof, P. J. van der Linden          & C. E. Hanson), 173–210. Cambridge University Press, Cambridge, UK.

Scheumann, W. and Alker, M. (2009). Cooperation on Africa's transboundary aquifers—             conceptual ideas. Hydrological Sciences Journal, 54(4), pp.793-802.