Impact of Climate Change on River Flows in the Black Volta River
Nobuhiko Sawai*1, Kenichiro Kobayashi*2, Apip*3, Kaoru Takara*4,
Hirohiko Ishikawa*4, Muneta Yokomatsu*4, Subhajyoti Samaddar*4,
Ayilari-Naa Juati*5, and Gordana Kranjac-Berisavljevic*6
*1Research and Development Center, Nippon Koei Co., Ltd., 2304 Inarihara, Tsukuba-shi, Ibaraki 300-1259, Japan
*2Research Center for Urban Safety and Security, Kobe University, Japan
*3Research Centre for Limnology, Indonesian Institute of Sciences, Indonesia
*4Disaster Prevention Research Institute, Kyoto University, Japan
*5Ghana Meteorological Agency, Ghana
*6University for Development Studies, Ghana
This paper assesses the impact of climate change in the Black Volta River by using data output from the atmospheric general circulation model with a 20-km resolution (AGCM20) through the Japanese Meteorological Agency (JMA) and the Meteorological Research Institute (MRI). The Black Volta, which flows mainly in Burkina Faso and Ghana in West Africa, is a major tributary of the Volta River. The basin covers 142,056 km2 and has a semi-arid tropical climate. Before applying AGCM20 output to a rainfall–runoff model, the performance of the AGCM20 rainfall data is investigated by comparing it with the observed rainfall in the Black Volta Basin. To assess the possible impact of rainfall change on river flow, a kinematic wave model, which takes into consideration saturated and unsaturated subsurface soil zones, was performed. The rainfall analysis shows that, the correlation coefficient of the monthly rainfall between the observed rainfall and AGCM20 for the present climate (1979–2004) is 0.977. In addition, the analysis shows that AGCM20 overestimates precipitation during the rainy season and underestimates the dry season for the present climate. The analysis of the AGCM20 output shows the precipitation pattern change in the future (2075–2099). In the future, precipitation is expected to increase by 3%, whereas evaporation and transpiration are expected to increase by 5% and by 8%, respectively. Also, daily maximum rainfall is expected to be 20 mm, or 60%, higher. Thus, the future climate in this region is expected to be more severe. The rainfall–runoff simulation is successfully calibrated at the Bamboi discharge gauging station in the Black Volta fromJune 2000 to December 2000 with 0.72 of the Nash–Sutcliffe model efficiency index. The model is applied with AGCM20 outputs for the present climate (1979–2004) and future climate (2075–2099). The results indicate that future discharge will decrease from January to July at the rate of the maximum of 50% and increase fromAugust to December at the rate of the maximumof 20% in the future. Therefore, comprehensive planning for both floods and droughts are urgently needed in this region.
-  IPCC, “Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change,” Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2013.
-  IPCC, IPCC Fourth Assessment Report, 2007.
-  IPCC, “What is a GCM?”
http://www.ipcc-data.org/ddc_gcm_guide.html [accessed Dec. 15, 2013]
-  T. Sayama, Y. Tachikawa, K. Takara, A. Masuda, and T. Suzuki, “Evaluating the Impact of Climate Change on Flood Disasters and Dam Reservoir Operation in the Yodo River Basin,” Journal of Japan Society of Hydrology & Water Resources, Vol.21, No.4, pp. 296-313, Jul., 2008.
-  S. Kim, Y. Tachikawa, E. Nakakita, K. Yorozu, and M. Shiiba, “Climate Change Impact on River Flow on the Tone River Basin, Japan,” Annual Journal of Hydraulic Engineering, JSCE, Vol.55, pp. 85-90, February, 2011.
-  Y. Tachikawa, S. Takino, Y. Ichikawa, and M. Shiiba, “Study on the Impact of Climate Change on River Flow Regime in the Mogami and Yoshino River Basins,” Annual Journal of Hydraulic Engineering, JSCE, Vol.53, pp. 475-580, February, 2009 (in Japanese).
-  GWP, Ghana,
http://www.gwp.org/es/WACDEP/IMPLEMENTATION/Where/Ghana/ [accessed Dec. 15, 2013]
-  B. A. Amisigo, N. van de Giesen, C. Rogers, W. E. I. Andah, and J. Friesen, “Monthly streamflow prediction in the Volta Basin of West Africa: A SISO NARMAX polynomial modelling,” Physics and Chemistry of The Earth, Vol.33, pp. 141-150, 2008.
-  S. Shaibu, S. N. Odai, K. A. Adjei, E. M. Osei, and F. O. Annor, “Simulation of runoff for the Black Volta Basin using satellite observation data,” International Journal of River Basin Management, Vol.10, No.3, pp. 245-254, 2012.
-  R. A. Kasei, “Modelling impacts of climate change on water resources in the Volta Basin, West Africa,” Master’s thesis, ULB Bonn, 2009.
-  M. McCartney, G. Forkuor, A. Sood, B. Amisigo, F. Hattermann, and L. Muthuwatta, “The water resource implications of changing climate in the Volta River Basin,” IWMI Research Report, Vol.146, 40p., Colombo, Sri Lanka, International Water Management Institute (IWMI), 2012.
-  E. Obuobie, “Estimation of groundwater recharge in the context of future climate change in theWhite Volta River Basin, West Africa,” Master’s thesis, Rheinischen Friedrich-Wilhelms-Universitat Bonn, 2008.
-  Boubacar BARRY, Emmanuel OBUOBIE, Marc ANDREINI,Winston ANDAH, and Mathilde PLUQUET, “The Volta River Basin. Comprehensive Assessment of Water Management in Agriculture. Comprehensive study of river basin development and management. Draft, January 2005.
-  P. G. Oguntunde, “Evapotranspiration and complimentarity relations in the water balance of the Volta Basin: Field measurements and GIS-based regional estimates,” Ecology and Development Series, Vol.22, 2004.
-  United Nations Department of Agriculture Natural Resources Conservation Service, Alfisols, 2012,
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/nedc/training/soil/?cid=nrcs142p2_053590 [accessed Jul. 7, 2014]
-  Department of Soil Science University of Wisconsin-Madison, Soil orders, 1999,
http://www.soils.wisc.edu/courses/SS325/soilorders.htm [accessed Dec. 15, 2013]
-  R. Mizuta, H. Yoshimura, H. Murakami, M. Matsueda, H. Endo, T. Ose, K. Kamiguchi, M. Hosaka, M. Sugi, S. Yukimoto, S. Kusunoki, and A. Kitoh, “Climate Simulations Using MRIAGCM3.2 with 20-km Grid,” Journal of the Meteorological Society of Japan, Vol.90A, pp. 233-258, 2012.
-  Y. Tachikawa, G. Nagatani, and K. Takara, “Development of stagedischarge relationship equation incorporating saturated-unsaturated flow mechanism,” Annual Journal of Hydraulic Engineering, JSCE, Vol.48, pp. 7-12, February, 2004.
-  B. Lehner, K. Verdin, and A. Jarvis, “New Global Hydrography Derived From Spaceborne Elevation Data,” Eos, Transactions American Geophysical Union, Vol.89, No.10, pp. 93-94, 2008.
-  J. E. Nash and Sutcliffe J. V. “River flow forecasting through conceptual models part I – A discussion of principles,” Journal of Hydrology, Vol.10, No.3, pp. 282-290, 1970.
-  T. Nakaegawa and E. Nakakita, Comment on “Effect of uncertainty in temperature and precipitation inputs and spatial resolution on the crop model” by K. Tatsumi, Y. and K. Takara, Hydrological Research Letters, Vol.6, pp. 13-14, 2012.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.