International Journal of Agricultural Policy and Research
Vol.2 (6), pp.238-255,June 2014
ISSN 2350-1561
Article ID JPR067/14/18 Pages
Copyright © 2014 Author(s) retain the copyright of this article. Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 3.0 International License

Original Research Paper

Water balance of the Juba and Shabelle River basins the Horn of Africa

Accepted 16 June, 2014

Mesenbet Y. Sebhat^*1 and J. Wenninger²

¹Bahir Dar University, College of Agriculture and Environmental  Science, Water Resources and Irrigation Management, Bahir Dar, P.O. Box 5501, Ethiopia.
²UNESCO-IHE Institute for Water Education, P.O. Box 3015, Delft, The Netherlands,TU-Delft, P.O. Box 5048, Delft, The Netherlands.

*Corresponding Author Email : mesyibseb@yahoo.com
Tel.: +251913212629

 Abstract

The main objectives of this paper are to quantify the tempo-spatial distribution and the water balance of the two transboundary rivers. Results indicated that the rivers have two peak flows during the Deyr (October to December) and Gu (April to June) flood seasons.  The  river  peak  flows  occur  in  October  and  September  in  the  Juba  and  Shabelle rivers, respectively.  The Shabelle River flow is decreased at the downstream runoff stations during the two peak flow seasons but there is only a very small flow reduction in the Juba River. The annual daily peak flows were observed  for the Juba River at the Luuq runoff station and for the Shabelle River at the Belet Weyne runoff station, but during the Hagaa (July to September) and Jilaal (January to March) seasons, the daily flow for the two rivers are very low and even close to zero.The actual evapotranspiration was determined as a remaining part of the water balance equation and it is mainly depended on the rainfall in each sub basin. The actual evapotranspiration contribution from the two rivers was almost negligible and ignored in the study area.  This is due to nearly negligible surface runoff contribution from each sub basin in Somalia and the sub basin areas are large compared to the river cross secti on that contributes to evaporation.

Key words: GIS data, water resource, catchment area, runoff station, peak flow, flow duration, exceedence probability, abstraction flow