Open access peer-reviewed chapter - ONLINE FIRST

Review of Hydrological Drought Analysis Status in Ethiopia

Written By

Kassa Abera and Admasu Gebeyehu

Submitted: December 17th, 2021 Reviewed: January 19th, 2022 Published: March 22nd, 2022

DOI: 10.5772/intechopen.102763

IntechOpen
Drought - Impacts and Management Edited by Murat Eyvaz

From the Edited Volume

Drought - Impacts and Management [Working Title]

Associate Prof. Murat Eyvaz, Dr. Ahmed Albahnasawi, MSc. Mesut Tekbaş and M.Sc. Ercan Gürbulak

Chapter metrics overview

23 Chapter Downloads

View Full Metrics

Abstract

Drought is a complex natural disaster unlike flood, which covers a large area when it occurred. This review was conducted on hydrological drought analysis and monitoring status in Ethiopia by reviewing the master plan of eight major river basins and previous research related to drought. A total of 24 article papers was reviewed and it is found that hydrological drought analysis studies cover only 8.33% of all of the river basins in Ethiopia. Researchers in the region have focused primarily on meteorological drought (37.5%) rather than hydrological and agricultural drought analysis. Although Ethiopia has long been dependent on rainfed agriculture for its economy and remains the primary livelihood of the population, the Ethiopian government has begun focusing on transitioning to an industrial economy, placing pressure on the water resource. In a region plagued by drought, drought analysis, and monitoring, drought early warning systems and effective mitigation measures are still limited and even lacking in some areas. Therefore, emphasis on hydrological drought analysis and development of suitable drought mitigation measurements is important to implement strategies for effective and sustainable water resource management by which water may remain available during the long dry seasons and the impacts of hydrological drought may be lessened.

Keywords

  • hydrological drought
  • drought mitigation
  • Ethiopian river basins

1. Introduction

Drought is a worldwide natural hazard and has a detrimental impact on society, the environment, and the economy [1]. Extreme hydrological events both high (flood) and low (drought) flow are of particular concern globally. Of these hydrological extremes, drought is the most complex and widespread [2]. It is one of the most common natural events that has devastating negative impacts on agriculture and water resources [3].

There is no universal definition for drought due to its complexity [4]. Therefore, meteorologists defined drought as a scarcity of precipitation [5, 6, 7, 8, 9, 10]; hydrologists have defined hydrological drought as scarcity of surface and subsurface water [5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]; agriculturalists and agronomists defined agricultural drought as related to soil moisture deficiency [3, 16, 17] and sociologists and economists defined the overall welfare crisis of the society caused by drought to be socioeconomical drought [4, 18, 19, 20, 21]. These types of droughts have accumulating effects, thus meteorological drought results in losses, such as crop stress, predation by pests, and disease due to low moisture, to the agricultural systems while hydrological drought causes the shortage of water supply, decrease in reservoir water level and groundwater volume, lower irrigation and hydropower production [14]. The accumulation of meteorological and hydrological drought results in socioeconomical drought in which the overall ecosystem will be disturbed and human and animal lives will be negatively impacted and even lost [15].

Historically, Ethiopia has faced multiple seasonal drought events due to erratic rainfall and climate change [22]. The most drought-prone areas in Ethiopia are in Northeast Ethiopia and the Upper Blue Nile basin, including the Northern Tigray region, some parts of Amhara regions, such as South Wollo, North Wollo, South Gondar, and Afar Region, most parts of Somalia Region, and Eastern parts of Oromia Region [1, 3, 23, 24, 25, 26, 27]. Drought in Ethiopia occurs at a recurrence interval of 3–10 years [1], and even though this frequent recurrence is common, there still lacks any firmly established drought mitigation measure for these events. Only short-term response efforts are provided in the form of food aid when food supplies have decreased significantly due to extended drought.

Meteorological drought analysis has been studied frequently, yet hydrological and agricultural drought analysis and monitoring are not studied adequately. It is thought that Ethiopia is a water tower in East Africa but water resource management over the region is not well developed. This aggravates the natural hazard, such as drought impact on human life. Hydrological drought has a great influence on water supply irrigation and power production by reducing the availability of surface and subsurface water. There are few dams and reservoirs in the country and most of them are hydropower plants. But there is a lack of water conservation to reduce drought impact when it occurs. Generally, drought monitoring and forecasting studies are untouched and need a thorough investigation to alleviate socioeconomic problems related to drought.

The objective of this review chapter is to assess the status of hydrological drought studies in Ethiopia by reviewing different previously studied article papers related to drought. A total of 24 article papers was reviewed and the master plan of the eight-river basin was also reviewed. Of these, only two papers were related to hydrological drought and the remains were about meteorological and other drought-related topics. This implies that hydrological drought studies in Ethiopia require further analysis, monitoring, and forecasting investigation. Therefore, it is important to do this kind of review to show the gap of drought studies over the region for future researchers, stakeholders, and planners to develop a suitable early warning system.

Advertisement

2. Materials and methods

2.1 Description of the study area

Ethiopia has an ample amount of water resources when compared to other African countries yet the development is still poor. There are 12 major river basins in the country which generate an annual runoff of 123 BM3 (Table 1). From these, Aysha and Ogaden river basins are dry and the Mereb and Denakle have insignificant streamflow over the year, the border basins from North to East direction (Figure 1). Eight river basins have a well-organized master plan, however, only the three river basins (Abbay, Awash, and Tekeze) are popularly studied for the development of irrigation, water supply, and hydropower projects. Different types of drought studies were also relatively studied in these river basins. In the Wabishebele river basin, one hydrological drought analysis was studied by Awas [26]. Abbay and Awash basins have good hydrometeorological data and are highly invested when compared to other river basins. This review is focused on the assessment of hydrological drought analysis and the drought mitigation approach of previous research in Ethiopia, related to drought.

River basinArea (km2)Annual runoff (BM3)Terminus
Abbay199,91252.6Mediterranean
Awash110,0004.6Within the country
Baro75,91223.6Mediterranean
Genale Dawa172,2595.8Indian Ocean
Omo Gibe79,00017.9Lake Turkana
Tekeze82,3507.6Mediterranean
Rift Valley52,0005.6Chew Bahir
Wabishebele202,2204.6Indian Ocean
Mereb59000.26Sudanese Wetland
Denakle64,3800.86Within the country
Aysha22230
Ogaden77,1200
Total1,123,276123.42

Table 1.

Characteristics of Ethiopian major river basins.

Source: River Basin Master Plan; Ministry of Water, Irrigation and Electricity, Ethiopia.

Figure 1.

Drought study information of Ethiopian river basins.

Figure 2.

Seasonal variation of streamflow over Ethiopian river basins.

Spatially, the Abbay river basin is the largest and it covers 43.1% of the surface runoff of the country. The general characteristics of each river basin in the country are given in Table 1. In Ethiopia, there is a high seasonal flow and rainfall variation. As shown in Figures 2 and 3, Abbay and Omo gibe river basins have a high flow when compare to other river basins and overall the maximum flow is obtained during the summer season from June to August (JJA).

Ethiopia has 12 major river basins, most of which are transboundary rivers except the Awash river. The total surface water is estimated at 124 BM3 and the groundwater potential is estimated near 30 BM3 [28]. Up to 70% of the surface water is originated from the central and western highlands on the western sides of the Great Rift Valley flow to the west into the Nile river basin system that covers 39% of the landmass and the remaining 30% of surface water originated from eastern highlands flow into east that covers 61% of the landmass.

Figure 3.

Mean monthly rainfall of eight river basins in Ethiopia.

2.2 Historical drought in Ethiopia

Ethiopia is experienced severe drought problems for the last decades. According to Mohammed et al., the most drought years in North East Highlands of Ethiopia were 1984, 1987, 1988, 1992, 1993, 1999, 2003, 2004, 2007, and 2008 [1]. Bayissa et al. also found that 1984/85 and 2003/04 were the extreme drought years in the Upper Blue Nile basin in Ethiopia [29]. Based on EM-DAT, 2014, the most severe drought years in Ethiopia from 1900 to 2013 were 1965, 1969, 1973, 1983, 1987, 1989, 1997, 1998, 1999, 2003, 2005, 2008, 2009, and 2012 with an average recurrence interval of 4 years [30]. Generally, the year 1984 was a bad drought event in Ethiopia and it was globally known. Here, all the above-stated drought years were analyzed based on meteorological drought indicators, especially standardized precipitation index (SPI) and palm drought severity index (PDSI).

2.3 Data collection and analysis

To review the status of hydrological drought conditions in Ethiopia, important data were collected from the Ministry of Water, Irrigation, and Electricity, department of Basin Development Authority. The river basin master plan was thoroughly reviewed and previous drought-related studies in Ethiopia were also assessed.

During this review, 24 articles and conference papers related to drought studies in Ethiopia were collected. From these, nine papers are meteorological drought studies, seven papers are general drought impact studies, and the remaining eight were agricultural, hydrological, and socioeconomic drought studies (Tables 2 and 3). Surprisingly, except for some general drought studies related to drought impact over the country, other drought studies were conducted in some specific parts of the country. Especially meteorological drought studies were highly focused on the Abbay river basin (Upper Blue Nile) and Awash river basin. Agricultural and socioeconomic drought studies slightly tried to see the overall drought conditions in Ethiopia. However, these are also not studied in-depth.

No.AuthorTitleDrought Category
1Philip et al. [22]Attribution analysis of the Ethiopian drought of 2015General
2Belayneh et al. [2]Long-term SPI drought forecasting in the Awash river basin in Ethiopia using wavelet neural network and wavelet support vector regression modelsMeteorological
3Yimer et al. 2017Meteorological drought assessment in northeast highlands of EthiopiaMeteorological
4Araya and Leo Stroosnijder, 2011Assessing drought risk and irrigation need in northern EthiopiaGeneral
5Enyew et al. [27]Assessment of the impact of climate change on hydrological drought in Lake Tana catchment, Blue Nile basin, EthiopiaHydrological
6Edosa et al., 2010Drought analysis in the Awash river basin, EthiopiaHydrometeorological
7USAID Report, 2018Economics of resilience to drought; Ethiopia analysisSocioeconomic
8Philip et al. [22]The drought in Ethiopia, 2015General
9Jjemba et al.Extreme drought in Ethiopia stretches drought management systemsSocioeconomic
10Gebrehiwot et al. [24]Spatial and temporal assessment of drought in the Northern highlands of EthiopiaMeteorological
11Bayissa et al. [17]Comparison of the performance of six drought indices in characterizing historical drought for the Upper Blue Nile basin, EthiopiaMeteorological
12Awass [26]Hydrological drought analysis occurrence, severity, risks: the case of Wabishebele river basin, EthiopiaHydrological
13EL Kenawy et al., 2016Changes in the frequency and severity of meteorological drought over Ethiopia from 1960 to 2013Meteorological
14Bayissa et al. [29]Spatio-temporal assessment of meteorological drought under the influence of varying record length: the case of Upper Blue Nile basin, EthiopiaMeteorological
15Zeleke et al. [18]Trend and periodicity of drought over EthiopiaMeteorological
16Teshome and Zhang [20]Increase of extreme drought over Ethiopia under climate warmingGeneral
17Viste et al. [19]Recent drought and precipitation tendencies in EthiopiaGeneral
18Getachew et al., 2020Application of artificial neural networks in forecasting a standardized precipitation evapotranspiration index for the Upper Blue Nile basinMeteorological
19Getachew, 2018Drought and its impacts in EthiopiaSocioeconomic
20Temam et al., 2019Long-term drought trends in ethiopia with implications for dryland agricultureAgricultural
21Dawit et al., 2019Comparison of meteorological and agriculture-related drought indicators across EthiopiaMeteorological and agricultural
22Y.A. Bayissa et al., 2018Developing a satellite-based combined drought indicator to monitor agricultural drought: a case study for EthiopiaAgricultural
23IDA GRANT-H0280, 2011Emergency drought recovery project (EDRP) in EthiopiaGeneral
24Sara Pantuliano and Mike Wekesa, 2008Improving drought response in pastoral areas of EthiopiaGeneral

Table 2.

Summary of selected literature related to drought studies in Ethiopia for this review.

N0.BasinArticle related to meteorological droughtArticles related to hydrological drought
1Abbay31
2Awash2
3Omo-Gibe1
4Rift Valley1
5Tekeze2
6Wabishebele1

Table 3.

Different types of drought studies status in each river basin.

Agricultural and socioeconomic drought studies were not focused on a particular river basin. Total 13 articles, including agricultural, socioeconomic, and general concepts, and drought impacts in Ethiopia were covered in some parts of the country without specifying a particular river basin.

Advertisement

3. Result and discussion

3.1 Hydrological drought status of the country

Ethiopia has been affected by drought many times over the last few centuries. However, drought studies and mitigation measurement investigation are still limited. Although there are few drought studies in the country; it is insufficient. Especially agricultural, hydrological and socioeconomic drought studies are untouched. As shown in Table 4 and Figure 4, most drought studies in Ethiopia are focused on meteorological drought and other general drought-related impact assessments. Meteorological drought is highly varying within the short-period scale in a month depending on the precipitation variability. Therefore, drought analysis from a short-time scale may lead to an erroneous conclusion. But hydrological drought study requires a long-term time scale greater than 6-month cumulative drought conditions of the study area. Mostly hydrological drought analysis is conducted annually based on and above, which will give some concrete information about the drought situation of a particular study area. From this review, hydrological drought studies were covered only 8.33%, which implies that it needs further study (one article in Abbay subbasin and one article from Wabishebele basin). Almost 78% of the study were concentrated in North Eastern and Upper Blue Nile basin, Tekeze and Abbay, and Awash river basin and which is meteorological drought (Table 3). Two researchers have been studied, hydrological drought in Abbay and Wabishebele basins (Table 3). But the remaining six basins are still not studied. Now the government of Ethiopia is planning to transform from agricultural lead to industrial transformation. This will have achieved when the natural resource will be properly managed and utilized. Water is the central part of all infrastructures development. However, the master plan of major river basins in Ethiopia focused only on the potential assessment of irrigation and hydropower, and there is no drought trend analysis and future hydrological drought forecasting. Hydrological drought affects irrigation, water supply, hydropower, and other water-related sectors. So, it is important to study the historical hydrological drought characteristics, such as frequency, magnitude, duration, severity, and future probability of the basin streamflow to satisfy all demands.

Type of droughtNumber of studiesPercentage (%)
Meteorological drought937.5
Hydrological drought28.33
Agricultural drought312.5
Socioeconomic drought312.5
General related to drought impact729.16
Total articles reviewed24100

Table 4.

Types of drought studies over Ethiopia.

Figure 4.

Percentage of drought studies in Ethiopia (MD = meteorological drought, HD = hydrological drought, AD = agricultural drought, SED = socioeconomical drought, and GD = general drought-related studies).

As far as reviewed from the basins master plan report and previous pieces of literature, there is no method adopted to analyze the hydrological drought in the region. But for sustainable water resource development, mitigation measurements of the extreme hydrological events, such as floods and drought, are impropriated. Otherwise, simply constructing any structure in the basin alone may not be a solution to improve poverty over the country.

3.2 Meteorological and agricultural drought

From the reviewed papers, 37.5% was covered meteorological drought analysis and monitoring studies, and agricultural drought studies were covered 12.5% (Table 4). Ethiopia is highly dependent on rainfed agriculture; so, meteorological and agricultural drought analysis, monitoring, and early warning system development are crucial. But still, there is no well-adopted drought analysis technique for a nationwide or a regional level. As a result, the development of drought early warning system has lacked. At the same time, hydrological drought analysis and monitoring is also key point for river basin development and water resource management. But due to its large input data requirement, hydrological drought study is not further investigated.

3.3 General drought-related studies

The socioeconomic of Ethiopia is continuously affected by frequent drought disasters. It is difficult to cope with subsequent years after drought has occurred. Up to 29.16% of the reviewed papers were related to drought impact, attribution, economics resilience to drought, extreme drought assessment, trend, and periodicity of drought in Ethiopia [4, 18, 19, 20]. Except for some articles, most of the reviewed articles were conducted in some parts of the country and did not give good information about the effect of drought in the country.

Advertisement

4. Conclusion

During any river basin master planning, considering extreme hydrological events, such as floods and drought, are the important issues for sustainable water resource development. Otherwise, simply focusing on the investigation and assessment of the available natural resources in a specific river basin and utilization of the resource will never bring development. Particular attention is to be given to drought-affected areas and conjunctive use of ground and surface water is encouraged. Aridity is the general characteristic of an arid climate and represents a (relatively) permanent condition, while drought is temporary. In an arid climate, drought can still occur when local conditions are even drier than normal. But 90% of the reviewed studies in Ethiopia were conducted on arid and semiarid areas of the region. Generally, hydrological drought study lacked in the country. Therefore, in the future, it is important to focus on hydrological drought monitoring and forecasting to achieve the sustainable utilization of available water resources in Ethiopia.

Advertisement

Acknowledgments

All the river basin master plan documents were freely accessed from the Ministry of Water, Irrigation, and Electricity of Ethiopia. Therefore, great gratitude is given to all the staff members of the ministry, especially for Basin Development Authority Department.

Advertisement

Conflict of interest

We declared that we have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this chapter.

References

  1. 1. Mohammed Y, Yimer F, Tadesse M, Tesfaye K. Meteorological drought assessment in north east highlands of Ethiopia. International Journal of Climate Change Strategies and Management. 2018;10:142-160
  2. 2. Belayneh A, Adamowski J, Khalil B, Ozga-zielinski B. Long-term SPI drought forecasting in the Awash river basin in Ethiopia using wavelet neural network and wavelet support vector regression models. Journal of Hydrology. 2014;508:418-429
  3. 3. Araya A, Stroosnijder L. Assessing drought risk and irrigation need in northern Ethiopia. Agricultural and Forest Meteorology. 2011;151:425-436
  4. 4. Mera GA. Drought and its impacts in Ethiopia. Weather and Climate Extremes. 2018;22:24-35
  5. 5. Keskin ME, Terzi Ö, Taylan ED, Küçükyaman D. Meteorological drought analysis using artificial neural networks. Academic Journals. 2011;6:4469-4477
  6. 6. Shen H, Yuan FEI, Ren L, Kong HAO, Tong RUI. Regional drought assessment using a distributed hydrological model coupled with standardized runoff index. Remote Sensing and GIS for Hydrology and Water Resources (IAHS Publ). 2015;368:397-402
  7. 7. Svoboda MD, Fuchs BA. Handbook of Drought Indicators and Indices. Geneva: World Meteorological Organization (WMO); 2017. ISBN 9781351967525
  8. 8. Pashiardis S, Michaelides S. Implementation of the standardized precipitation index (SPI) and the reconnaissance drought index (RDI) for regional drought assessment: A case study for. European Water. 2008;23:57-65
  9. 9. Mohammed Y. Meteorological drought assessment in north east highlands of Ethiopia. International Journal of Climate Change Strategies and Management. 2018;10(1):121-141. DOI: 10.1108/IJCCSM-03-2017-0059
  10. 10. Zargar A, Sadiq R, Naser B, Khan FI. A review of drought indices. NRC Research Press. Environmental Reviews. 2004;19:333-349
  11. 11. Khanna M. Hydrological Drought Indices. New Delhi, India: Water Technol. Centre, Indian Agric. Res; 2010
  12. 12. Trambauer P, Werner M, Winsemius HC, Maskey S, Dutra E, Uhlenbrook S. Hydrological drought forecasting and skill assessment for the Limpopo river basin, Southern Africa. Hydrology and Earth System Sciences. 2015;19:1695-1711
  13. 13. Abcdef IWY, Adef MB. Hydrological Drought Index Based on Reservoir Capacity—Case Study of Batujai Dam in Lombok Island. Indonesia: West Nusa Tenggara; 2018
  14. 14. Van Loon AF. Hydrological drought explained. Wiley Interdisciplinary Reviews Water. 2015;2:359-392
  15. 15. Boudad B, Sahbi H, Manssouri I. Analysis of meteorological and hydrological drought based in SPI and SDI index in the Inaouen Basin (Northern Morocco). Journal of Materials and Environmental Sciences. 2018;9:219-227
  16. 16. Tsige DT, Uddameri V, Forghanparast F. Comparison of meteorological and agriculture-related drought indicators across Ethiopia. Basel, Switzerland: MDPI Water; 2019
  17. 17. Bayissa Y, Maskey S, Tadesse T, van Andel SJ, Moges S, van Griensven A, et al. Comparison of the performance of six drought indices in characterizing historical drought for the upper Blue Nile basin, Ethiopia. Geosciences. 2018;8:81
  18. 18. Zeleke TT. Trend and periodicity of drought over Ethiopia. International Journal of Climatology. 2017. DOI: 10.1002/joc.5122
  19. 19. Viste E, Korecha D, Sorteberg A. Recent drought and precipitation tendencies in Ethiopia. Theoretical and Applied Climatology. 2013. DOI: 10.1007/s00704-012-0746-3
  20. 20. Teshome A. Increase of extreme drought over Ethiopia under climate warming. Hindawi: Advances in Meteorology. 2019;2019:18. DOI: 10.1155/2019/5235429
  21. 21. Ali A. Economics of Resilience to Drought—Somalia Analysis. USA: USAID; 2017. pp. 1-45
  22. 22. Philip S, Kew SF, van Oldenborgh GJ, Otto F, O’Keefe S, Haustein K, et al. Attribution analysis of the Ethiopian drought of 2015. Journal of Climate. 2018;31:2465-2486
  23. 23. Chemeda D, Mukand E, Babel S. Drought analysis in the Awash river basin, Ethiopia. Water Resources Management. 2010;24:1441-1460
  24. 24. Gebrehiwot T, van der Veen A, Maathuis B. Spatial and temporal assessment of drought in the Northern highlands of Ethiopia. International Journal of Applied Earth Observation and Geoinformation. 2011;13:309-321
  25. 25. Gissila T, Black E, Grimes DIF, Slingo JM. Seasonal forecasting of the Ethiopian summer rains. International Journal of Climatology. 2004;24:1345-1358
  26. 26. Awass AA. Hydrological Drought Analysis—Occurrence, Severity, Risks: The Case of Wabi Shebele River Basin. German: University of Siegen; 2009 [Dissertation]
  27. 27. Van Lanen HAJ, Enyew B. Assessment of the impact of climate change on hydrological drought in Lake Tana catchment, Blue Nile basin, Ethiopia. Journal of Geosciences. 2014;03:174
  28. 28. Berhanu B, Seleshi Y, Melesse AM. Nile River Basin: Ecohydrological Challenges, Climate Change and Hydropolitics. Switzerland: Springer International Publishing. pp. 1-718
  29. 29. Bayissa YA, Moges SA, Xuan Y, Van Andel SJ, Maskey S, Solomatine DP, et al. Influence de la durée des chroniques météorologiques sur la caractérisation des sécheresses météorologiques du bassin supérieur du Nil Bleu (Ethiopie). Hydrological Sciences Journal. 2015;60:1927-1942
  30. 30. Masih I, Maskey S, Trambauer P. A Review of Droughts in the African Continent: A Geospatial and Long-Term Perspective. European Geosciences Union. Hydrology and Earth System Sciences. Copernicus Publications; 2014

Written By

Kassa Abera and Admasu Gebeyehu

Submitted: December 17th, 2021 Reviewed: January 19th, 2022 Published: March 22nd, 2022