Long-Term Drought Trends in Ethiopia with Implications for Dryland Agriculture

Dawd Temam,Stephen Ekwaro-Osire,E Annette Hernandez,Ghazal Mohammadi,Venkatesh Uddameri

doi:10.3390/w11122571

Dawd Temam, Stephen Ekwaro-Osire + Show 3 more

Open Access

https://doi.org/10.3390/w11122571

Copy DOI

Journal: Water	Publication Date: Dec 6, 2019
Citations: 34	License type: CC BY 4.0

Affiliation: Jimma University, Texas Tech University

Abstract

Intraseason and seasonal drought trends in Ethiopia were studied using a suite of drought indicators—standardized precipitation index (SPI), standardized precipitation evapotranspiration index (SPEI), Palmer drought severity index (PDSI) and Z-index for Meher (long-rainy), Bega (dry), and Belg (short-rainy) seasons—to identify drought-causing mechanisms. Trend analysis indicated shifts in late-season Meher precipitation into Bega in the southwest and southcentral portions of Ethiopia. Droughts during Bega (October–January) are largely temperature controlled. Short-term temperature-controlled hydrologic processes exacerbate rainfall deficits during Belg (February–May) and highlight the importance of temperature- and hydrology-induced soil dryness on production of short-season crops such as tef. Droughts during Meher (June–September) are largely driven by precipitation declines arising from the narrowing of the intertropical convergence zone (ITCZ). Increased dryness during Meher has severe consequences on the production of corn and sorghum. PDSI is an aggressive indicator of seasonal droughts suggesting the low natural resilience to combat the effects of slow-acting, moisture-depleting hydrologic processes. The lack of irrigation systems in the nation limits the ability to combat droughts and improve agricultural resilience. There is an urgent need to monitor soil moisture (a key agro-hydrologic variable) to better quantify the impacts of meteorological droughts on agricultural systems in Ethiopia.

Highlights

Ethiopia is predominantly rural with a large population depending on agriculture and pastoral activities, but there has been limited development of surface water and groundwater resources for irrigation [1]
The government of Ethiopia has adopted a national policy to deal with droughts [5] and requires local stakeholder-driven drought contingency planning to foster sustainable water resources management [6]
The results suggest that dryness is increasing at a rate of 5% per decade, while the drought intensification rate is about 10%

Summary

Introduction

Ethiopia is predominantly rural with a large population depending on agriculture and pastoral activities, but there has been limited development of surface water and groundwater resources for irrigation [1]. Droughts have frequently plagued Ethiopia and are a major climatic hazard that impacts the long-term sustainability of this rapidly growing African nation [3,4]. The government of Ethiopia has adopted a national policy to deal with droughts [5] and requires local stakeholder-driven drought contingency planning to foster sustainable water resources management [6]. Droughts are primarily caused by atmospheric moisture deficits (meteorological droughts). They propagate through hydrologic systems and cause reductions in water supplies

Objectives

Methods

Results