Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.936 IF 4.936
  • IF 5-year value: 5.615 IF 5-year
  • CiteScore value: 4.94 CiteScore
  • SNIP value: 1.612 SNIP 1.612
  • IPP value: 4.70 IPP 4.70
  • SJR value: 2.134 SJR 2.134
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 107 Scimago H
    index 107
  • h5-index value: 63 h5-index 63
Volume 15, issue 3
Hydrol. Earth Syst. Sci., 15, 1023–1034, 2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Climate, weather and hydrology of East African Highlands

Hydrol. Earth Syst. Sci., 15, 1023–1034, 2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 24 Mar 2011

Research article | 24 Mar 2011

Rain event properties at the source of the Blue Nile River

A. T. Haile2,1, T. H. M. Rientjes1, E. Habib2, V. Jetten1, and M. Gebremichael3 A. T. Haile et al.
  • 1Department of Water Resources, Faculty of Geoinformation Science and Earth Observation, University of Twente, P.O. Box 6, Enschede, 7500AA, The Netherlands
  • 2Department of Civil Engineering, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
  • 3Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA

Abstract. In the present study, spatial and temporal patterns of rain event properties are analysed. These event properties are rain event depth, event duration, mean event rain rate, peak rain rate and the time span between two consecutive rain events which is referred to as inter-event time (IET). In addition, we assessed how rain event properties change when the period over which rainfall data is aggregated changes from 1 to 6 min and when the minimum inter-event time (MIT) changes from 30 min to 8 h. Rainfall data is obtained from a field campaign in two wet seasons of June–August (JJA) of 2007 and 2008 in Gilgel Abbay watershed that is situated at the source basin of the Upper Blue Nile River in Ethiopia. The rainfall data was automatically recorded at eight stations. The results revealed that rain event depth is more related to peak rain rate than to event duration. At the start and towards the end of the wet season, the rain events have larger depth with longer duration and longer IET than those in mid-season. Event rain rate and IET are strongly related to terrain elevation. Sekela which is on a mountain area has the shortest IET while Bahir Dar which is at the south shore of Lake Tana has the longest IET. The period over which rainfall data is aggregated significantly affected the values of rain event properties that are estimated using relatively small value (30 min) of MIT but its effect diminished when the MIT is increased to 8 h. It is shown that increasing the value of MIT has the largest effect on rain event properties of mountain stations that are characterised by high rainfall intermittency.

Publications Copernicus