Drought Analysis in the Awash River Basin, Ethiopia

This study analyzes drought characteristics in the Awash River Basin of Ethiopia based on meteorological and hydrological variables. Standardized precipitation index is used for temporal and spatial analyses of meteorological drought and the theory of runs is used to define hydrological drought by considering streamflow as the drought indicator. Drought severity maps are generated using Arc View/GIS by summarizing the percentage of occurrence of droughts in areas within the study basin. Extreme drought category on 12-month time scale indicated that extreme events occur most frequently in the Upper and Middle Awash Basin. However, while considering the overall categories of drought, the most frequent droughts occurred in the Middle and Lower Awash Basin during the period of analysis. Similarly, results based on hydrological drought analysis shows that the severest drought events occurred in the Middle Awash Basin during May 1988 to June 1988 and April 1998 to May 1998. Analysis of the relationship between meteorological and hydrological drought indices in the basin shows that occurrence of hydrological drought event at Melka Sedi stream gauging station lags meteorological drought event in the Upper Awash on average by 7 months with a variation of 3 to 13 months.

[1]  S. Durrans,et al.  Regionalization of Low-Flow Frequency Estimates: AN Alabama Case Stui)y , 1996 .

[2]  M. A. Kohler,et al.  Hydrology for engineers , 1958 .

[3]  Won-Tae Kwon,et al.  Spatial and temporal comparisons of droughts over Korea with East Asia , 2003 .

[4]  Luis S. Pereira,et al.  Spatial Patterns and Temporal Variability of Drought in Western Iran , 2009 .

[5]  N. Guttman.  COMPARING THE PALMER DROUGHT INDEX AND THE STANDARDIZED PRECIPITATION INDEX 1 , 1998 .

[6]  J. Dracup,et al.  On the definition of droughts , 1980 .

[7]  A. Sutera,et al.  Spatial Variability of Drought: An Analysis of the SPI in Sicily , 2003 .

[8]  R. Vogel,et al.  Probability Distribution of Low Streamflow Series in the United States , 2002 .

[9]  Z. Abate.  Water Resources Development in Ethiopia: An Evaluation of Present Experience and Future Planning Concepts , 1995 .

[10]  George Tsakiris,et al.  Assessment of Hydrological Drought Revisited , 2009 .

[11]  Mukand S. Babel,et al.  Farmers' Perception of Water Management under Drought Conditions in the Upper Awash Basin, Ethiopia , 2006 .

[12]  M. Hayes,et al.  An evaluation of the Standardized Precipitation Index, the China‐Z Index and the statistical Z‐Score , 2001 .

[13]  B. Lloyd‐Hughes,et al.  A drought climatology for Europe , 2002 .

[14]  G. Tsakiris,et al.  Regional Drought Assessment Based on the Reconnaissance Drought Index (RDI) , 2007 .

[15]  A. Shaban.  Indicators and Aspects of Hydrological Drought in Lebanon , 2009 .

[16]  Luis S. Pereira,et al.  Prediction of SPI Drought Class Transitions Using Markov Chains , 2007 .

[17]  Gary D. Tasker,et al.  A COMPARISON OF METHODS FOR ESTIMATING LOW FLOW CHARACTERISTICS OF STREAMS , 1987 .

[18]  Mathieu Rouault,et al.  Intensity and spatial extension of drought in South Africa at different time scales , 2004 .

[19]  Antonino Cancelliere,et al.  An analytical formulation of return period of drought severity , 2003 .

[20]  Ali Umran Komuscu,et al.  Using the SPI to Analyze Spatial and Temporal Patterns of Drought in Turkey , 1999 .

[21]  P. Domonkos.  Recent Precipitation Trends in Hungary in the Context of Larger Scale Climatic Changes , 2003 .

[22]  Improving Drought Management in the West: The Role of Mitigation and Preparedness: Report to the Western Water Policy Review Advisory Commission , 1997 .

[23]  C. Serra,et al.  Patterns of monthly rainfall shortage and excess in terms of the standardized precipitation index for Catalonia (NE Spain) , 2001 .

[24]  Jenq-Tzong Shiau,et al.  Fitting Drought Duration and Severity with Two-Dimensional Copulas , 2006 .

[25]  R. P. Pandey,et al.  Streamflow Drought Severity Analysis of Betwa River System (India) , 2008 .

[26]  Exploration de l’indicateur standardisé de précipitation à l’aide d’une analyse statistique régionale , 2002 .

[27]  D. Wilhite,et al.  CHAPfER2UNDERSTANDING THE DROUGHT PHENOMENON:THE ROLE OF DEFINITIONS , 1985 .

[28]  M. Hayes,et al.  Using the standardized precipitation index for flood risk monitoring , 2002 .

[29]  George Tsakiris,et al.  Towards a Drought Watch System based on Spatial SPI , 2004 .