Title: The long-term trends in hydro-climatology of the Dinder and Rahad basins, Blue Nile, Ethiopia/Sudan

Authors: Khalid Hassaballah; Yasir A. Mohamed; Stefan Uhlenbrook

Addresses: IHE-Delft Institute for Water Education, P.O. Box 3015, 2601DA Delft, The Netherlands; Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; The Hydraulics Research Center, P.O. Box 318, Wad Medani, Sudan ' IHE-Delft Institute for Water Education, P.O. Box 3015, 2601DA Delft, The Netherlands; Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; The Hydraulics Research Center, P.O. Box 318, Wad Medani, Sudan ' IHE-Delft Institute for Water Education, P.O. Box 3015, 2601DA Delft, The Netherlands; Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands; UNESCO, Villa La Colombella, 06134 Colombella Alta, Perugia, Italy

Abstract: This paper examines the long-term trends of streamflow, rainfall and temperature over the Dinder and Rahad River basins. Streamflow of the Rahad River showed significant increasing trends in both the annual and seasonal flows. There was no detectable change in the mean annual and seasonal flow patterns of the Dinder. However, the analysis of seasonal maxima suggested a shift towards decreased flows during the high flow period (August) and increased flows during the low flow period (November). The Dinder maxima of August decreased from 517 m³/s over the early part of the record (1972-1991) to 396 m³/s over the latest years (1992-2011). The mean annual temperature showed significant increasing trends at the rate of 0.24 and 0.30 C/decade in the examined stations. Rainfall showed no significant change. The result of this study suggests other factors than climate variability (e.g., land use and land cover changes) to be responsible for streamflow alterations.

Keywords: time series analysis; hydro-climatic trend; Dinder and Rahad basins; Mann-Kendall; Pettitt test; IHA; non-parametric analysis; Ethiopia; Sudan.

DOI: 10.1504/IJHST.2019.103447

International Journal of Hydrology Science and Technology, 2019 Vol.9 No.6, pp.690 - 712

Received: 17 Mar 2017
Accepted: 16 Mar 2018
Published online: 06 Nov 2019 *

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