Hydro-Climatic Variability: A Characterisation and Trend Study of the Awash River Basin, Ethiopia

Mahtsente Tibebe Tadese,Birhanu Zemadim,Lalit Kumar,Richard Koech

doi:10.3390/hydrology6020035

Abstract

The objective of this study was to characterize, quantify and validate the variability and trends of hydro-climatic variables in the Awash River Basin (ARB) in Ethiopia using graphical and statistical methods. The rainfall and streamflow trends and their relationships were evaluated using the regression method, Mann–Kendall (MK) test and correlation analysis. The analysis focused on rainfall and streamflow collected from 28 and 18 stations, respectively. About 85.7% and 75.3% of the rainfall stations exhibited normal to moderate variability in annual and June to September rainfall, respectively, whereas 96.43% of rainfall stations showed high variability in March to May. The MK test showed that most of the significant trends in annual rainfall were decreasing except in two stations. These research findings provide valuable information on the characteristics, variability, and trend of rainfall and streamflow necessary for the design of sustainable water management strategies and to reduce the impact of droughts and floods in the ARB.

Highlights

In recent decades, concerns around water resources and climate change have gained global significance
The current analysis focused on the two hydro-climatic variables: rainfall andwere streamflow from 28 and 18 stations, respectively (Figure 1)
Awash and Lower Awash, while unimodal rainfall was indicated in the Upper Awash

Summary

Introduction

Concerns around water resources and climate change have gained global significance. Water resources are exposed to high spatial and temporal hydro-climatic variability, leading to major challenges affecting the economic development [1]. Climate change and an altered water supply regime have necessitated the need to investigate the relationships between climate and water resources. The availability and accessibility of water resources are mainly reliant on climate and environment of the area. The rainfall variability, alteration in temperature and other climatic variables significantly affect the variation in streamflow level and time of hydrologic events [2]. The level of streamflow will be affected by several factors which include rainfall characteristics, soil physical properties, watershed factors and human activities [3]

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Discussion

Conclusion