Your search found 17 records
1 Abedin, M. Z.; Adgo, E.; Tefera, M.; Wondimkun, Y. 2006. Recent achievements and priorities in irrigation water management research in Ethiopia with particular reference to Amhara region. In Awulachew, Seleshi Bekele; Menker, M.; Abesha, D.; Atnafe, T.; Wondimkun, Y. (Eds.). Best practices and technologies for small scale agricultural water management in Ethiopia. Proceedings of a MoARD /MoWR /USAID / IWMI Symposium and Exhibition held at Ghion Hotel, Addis Ababa, Ethiopia, 7-9 March, 2006. Colombo, Sri Lanka: IWMI. pp.121-128.
Irrigation management ; Water potential ; Villages ; Participatory management ; Social participation / Ethiopia / Amhara Region
(Location: IWMI-HQ Call no: IWMI 631.7.1 G136 AWU Record No: H039825)
2 White, E. D.; Easton, Z. M.; Fuka, D. R.; Collick, A. S.; Adgo, E.; McCartney, Matthew; Awulachew, Seleshi Bekele; Selassie, Y. G.; Steenhuis, T. S. 2008. Adapting the soil and water assessment tool (SWAT) for the Nile Basin. In Humphreys, E.; Bayot, R. S.; van Brakel, M.; Gichuki, F.; Svendsen, M.; Wester, P.; Huber-Lee, A.; Cook, S. Douthwaite, B.; Hoanh, Chu Thai; Johnson, N.; Nguyen-Khoa, Sophie; Vidal, A.; MacIntyre, I.; MacIntyre, R. (Eds.). Fighting poverty through sustainable water use: proceedings of the CGIAR Challenge Program on Water and Food, 2nd International Forum on Water and Food, Addis Ababa, Ethiopia, 10-14 November 2008. Vol.3. Water benefits sharing for poverty alleviation and conflict management; Drivers and processes of change. Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food. pp.22-26.
River basin management ; Watershed management ; Soil management ; Assessment ; Simulation models ; Water balance ; Water quality ; Stream flow ; Sedimentation ; Infiltration ; Runoff ; Climate / Ethiopia / Nile River Basin / Blue Nile River / Lake Tana Watershed / Anjeni Watershed
(Location: IWMI HQ Call no: IWMI 333.91 G000 HUM Record No: H041847)
http://cgspace.cgiar.org/bitstream/handle/10568/3708/IFWF2_proceedings_Volume%20III.pdf?sequence=1
https://vlibrary.iwmi.org/pdf/H041847.pdf
https://vlibrary.iwmi.org/pdf/H041847.pdf
(0.19 MB) (4.879MB)
3 Steenhuis, T. S.; Collick, A. S.; Easton, Z. M.; Leggesse, E. S.; Bayabil, H. K.; White, E. D.; Awulachew, Seleshi Bekele; Adgo, E.; Ahmed, A. A. 2009. Predicting discharge and sediment for the Abay (Blue Nile) with a simple model. Hydrological Processes, 23:3728-3737. [doi: https://doi.org/10.1002/hyp.7513]
Simulation models ; Forecasting ; Erosion ; Sedimentation ; Calibration ; Water balance ; Rainfall-runoff relationships ; River basins ; Climate / Ethiopia / Sudan / Egypt / Abay River / Blue Nile River
(Location: IWMI HQ Call no: e-copy only Record No: H042576)
(0.28 MB)
Models accurately representing the underlying hydrological processes and sediment dynamics in the Nile Basin are necessary for optimum use of water resources. Previous research in the Abay (Blue Nile) has indicated that direct runoff is generated either from saturated areas at the lower portions of the hillslopes or from areas of exposed bedrock. Thus, models that are based on infiltration excess processes are not appropriate. Furthermore, many of these same models are developed for temperate climates and might not be suitable for monsoonal climates with distinct dry periods in the Nile Basin. The objective of this study is to develop simple hydrology and erosion models using saturation excess runoff principles and interflow processes appropriate for a monsoonal climate and a mountainous landscape. We developed a hydrology model using a water balance approach by dividing the landscape into variable saturated areas, exposed rock and hillslopes. Water balance models have been shown to simulate river flows well at intervals of 5 days or longer when the main runoff mechanism is saturation excess. The hydrology model was developed and coupled with an erosion model using available precipitation and potential evaporation data and a minimum of calibration parameters. This model was applied to the Blue Nile. The model predicts direct runoff from saturated areas and impermeable areas (such as bedrock outcrops) and subsurface flow from the remainder of the hillslopes. The ratio of direct runoff to total flow is used to predict the sediment concentration by assuming that only the direct runoff is responsible for the sediment load in the stream. There is reasonable agreement between the model predictions and the 10-day observed discharge and sediment concentration at the gauging station on Blue Nile upstream of Rosaries Dam at the Ethiopia–Sudan border.
4 Collick, A. S.; Easton, Z. M.; Ashagrie, T.; Biruk, B.; Tilahun, S.; Adgo, E.; Awulachew, Seleshi Bekele; Zeleke, G.; Steenhuis, T. S. 2009. A simple semi-distributed water balance model for the Ethiopian highlands. Hydrological Processes, 23:3718-3727. [doi: https://doi.org/10.1002/hyp.7517]
Rainfall-runoff relationships ; Soil water ; Water balance ; Models ; Calibration ; Hydrology ; River basins ; Watersheds ; Climate / Ethiopia / Sudan / Egypt / Nile Basin / Upper Nile Basin / Yeku Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H042577)
(0.31 MB)
The discharge of the Nile River is highly dependent on the flow generated in the highlands of Ethiopia. However, little is known about the local (i.e. small scale) watershed hydrological response, due in part to a lack of long duration, continuous hydrological data. The goal of this paper was to develop a realistic, simple model that is useful as a tool for planning watershed management and conservation activities so that the effects of local interventions on stream flow can be predicted at a larger scale. The developed model is semi-distributed in that it divides the watershed into different regions that become hydrologically active given different amounts of effective cumulative rainfall after the start of the rainy season. A separate water balance is run for each of the hydrologic regions using rainfall and potential evaporation as the major inputs. Watershed parameters that were calibrated included the amount of water required before each region becomes hydrologically active, the fraction of soil water that becomes runoff and subsurface flow, and aquifer characteristics, Model validation indicated that daily discharge values were predicted reasonably well with Nash Sutcliffe values ranging from 0Ð56 to 0Ð78. Despite the large distance between the test watersheds, the input parameter values for the watershed characteristic were remarkably similar for the humid highlands, indicating that the model could be used to predict discharge in un-gauged basins in the region. As expected, the watershed in the semi-arid region behaved somewhat differently than the other three watersheds. Good quality precipitation data, even for short durations, were key to the effective modelling of runoff in the highland watersheds.
5 White, E. D.; Easton, Z. M.; Fuka, D. R.; Collick, A. S.; Adgo, E.; McCartney, Matthew; Awulachew, Seleshi Bekele; Selassie, Y. G.; Steenhuis, T. S. 2011. Development and application of a physically based landscape water balance in the SWAT model. Hydrological Processes, 25(6):915-925. [doi: https://doi.org/ 10.1002/hyp.7876]
Simulation models ; Hydrology ; Water balance ; Water table ; Runoff ; Stream flow ; Watersheds ; River basins / Ethiopia / USA / Blue Nile River / Gumera Watershed / New York / Catskill Mountains / Town Brook Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H043240)
(0.61 MB)
Watershed scale hydrological and biogeochemical models rely on the correct spatial-temporal prediction of processes governing water and contaminant movement. The Soil and Water Assessment Tool (SWAT) model, one of the most commonly used watershed scale models, uses the popular curve number (CN) method to determine the respective amounts of infiltration and surface runoff. Although appropriate for flood forecasting in temperate climates, the CN method has been shown to be less than ideal in many situations (e.g. monsoonal climates and areas dominated by variable source area hydrology). The CN model is based on the assumption that there is a unique relationship between the average moisture content and the CN for all hydrologic response units (HRUs), and that the moisture content distribution is similar for each runoff event, which is not the case in many regions. Presented here is a physically based water balance that was coded in the SWAT model to replace the CN method of runoff generation. To compare this new water balance SWAT (SWAT-WB) to the original CN-based SWAT SWAT-CN), two watersheds were initialized; one in the headwaters of the Blue Nile in Ethiopia and one in the Catskill Mountains of New York. In the Ethiopian watershed, streamflow predictions were better using SWAT-WB than SWAT-CN [Nash–Sutcliffe efficiencies (NSE) of 0Ð79 and 0Ð67, respectively]. In the temperate Catskills, SWAT-WB and SWAT-CN predictions were approximately equivalent (NSE >0Ð70). The spatial distribution of runoff-generating areas differed greatly between the two models, with SWAT-WB reflecting the topographical controls imposed on the model. Results show that a water balance provides results equal to or better than the CN, but with a more physically based approach.
6 Getahun, M.; Adgo, E.; Atalay, A. 2011. Impacts of irrigation on soil characteristics in selected irrigation schemes in the Upper Blue Nile Basin. In Melesse, A. M. (Ed.). Nile River Basin: hydrology, climate and water use. Dordrecht, Netherlands: Springer. pp.383-399.
Soil salinity ; Irrigation schemes ; Water quality ; River basins ; Soil properties / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: 551.483 G136 MEL Record No: H044039)
7 Collick, A. S.; Easton, Z. M.; Adgo, E.; Awulachew, Seleshi B.; Zeleke, G.; Steenhuis, T. S. 2008. Application of a physically-based water balance model on four watersheds throughout the Upper Nile Basin in Ethiopia. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.93-113.
Water balance ; Models ; Watersheds ; River Basins ; Hydrology ; Soil conservation ; Evapotranspiration ; Runoff ; Rain ; Discharge ; Calibration ; Water content / Ethiopia / Blue Nile River Basin / Yeku Watershed / Maybar Watershed / Andit Tid Watershed / Anjeni Watershed
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044303)
(1.46 MB)
8 Steenhuis, T. S.; Collick, A. S.; Awulachew, Seleshi B.; Adgo, E.; Ahmed, A. A.; Easton, Z. M. 2008. Modelling erosion and sedimentation in the Upper Blue Nile. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.200-212.
Erosion ; Sedimentation ; Simulation models ; Rainfall-runoff relationships ; Rivers ; Flow discharge / Ethiopia / Upper Blue Nile / Abay Blue Nile
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044323)
(0.82 MB)
9 Getahun, M.; Adgo, E.; Atalay, A. 2008. Impacts of irrigation on soil characteristics in selected irrigation schemes in the Upper Blue-Nile Basin. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.315-332.
Soil salinity ; Soil properties ; Chemicophysical properties ; Irrigation schemes ; Water quality / Ethiopia / Upper Blue Nile River Basin
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044335)
(1.27 MB)
10 Steenhuis, T. S.; Easton, Z. M.; Awulachew, Seleshi Bekele; Ahmed, A. A.; Bashar, K. E.; Adgo, E.; Selassie, Y. G.; Tilahun, S. A. 2012. The Nile Basin sediment loss and degradation, with emphasis on the Blue Nile. In Awulachew, Seleshi Bekele; Smakhtin, Vladimir; Molden, David; Peden D. (Eds.). The Nile River Basin: water, agriculture, governance and livelihoods. Abingdon, UK: Routledge - Earthscan. pp.112-132.
River basins ; Sedimentation ; Sediment pollution ; Runoff ; Highlands ; Gully erosion ; Simulation models ; Reservoirs ; Watersheds ; Assessment ; Water balance ; Spatial distribution / Africa / Nile River Basin / Blue Nile River Basin
(Location: IWMI HQ Call no: IWMI Record No: H045314)
(1.40MB)
11 Nigussie, Z.; Tsunekawa, A.; Haregeweyn, N.; Adgo, E.; Nohmi, M.; Tsubo, M.; Aklog, D.; Meshesha, D. T.; Abele, S. 2017. Factors influencing small-scale farmers’ adoption of sustainable land management technologies in north-western Ethiopia. Land Use Policy, 67:57-64. [doi: https://doi.org/10.1016/j.landusepol.2017.05.024]
Small scale farming ; Farmer participation ; Sustainable land management ; Technology ; Water conservation ; Soil conservation ; Land degradation ; Watersheds ; Drought ; Socioeconomic environment ; Multivariate analysis ; Models / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048585)
(0.54 MB)
Land degradation is a serious global problem because it leads to losses in food production and thus jeopardizes food security worldwide, particularly in developing countries. Despite numerous efforts to introduce sustainable land management (SLM) strategies and practices, their adoption by the primary target group, small-scale farmers in developing countries, has been [s]low. This study assesses the problem for the case of Ethiopia. The aim was to analyze the underlying factors that affect the adoption of SLM technologies in the Upper Blue Nile Basin. A detailed survey of 300 households and 1010 farm plots was conducted. Data were analyzed by using both descriptive and econometric analyses. Results show that farmers’ adoption of interrelated SLM measures depended on a number of socio-economic and farm-related factors in combination with the characteristics of the technologies themselves. For example, plot size and the availability of labor, as well as the gender of the household head, affected which SLM technologies were adopted by certain types of households. The adoption of SLM measures depended on the adaptive economic capacity of the farmers, which can be quite diverse even within a small region and can differ from the adoption potential in other regions. Our results suggest that SLM policies and programs have to be individually designed for specific target groups within specific regions, which in turn means that “one size fits all” and “across the board” strategies – which are quite common in the field of SLM – should be abandoned by development agencies and policymakers.
12 Beyene, A. A.; Verhoest, N. E. C.; Tilahun, S.; Alamirew, T.; Adgo, E.; Nyssen, J. 2019. Irrigation efficiency and shallow groundwater in anisotropic floodplain soils near Lake Tana, Ethiopia. Irrigation and Drainage, 68(2):365-378. [doi: https://doi.org/10.1002/ird.2320]
Irrigation schemes ; Irrigation efficiency ; Floodplains ; Groundwater table ; Groundwater recharge ; Water levels ; Surface water ; Soil chemicophysical properties ; Soil moisture ; Evapotranspiration / Ethiopia / Lake Tana
(Location: IWMI HQ Call no: e-copy only Record No: H049344)
(0.81 MB)
Field experiments were conducted (December 2014 to May 2015) in a small irrigation scheme (60 ha) to study the effect of flood irrigation on anisotropic soils with shallow groundwater in the Lake Tana floodplains of Ethiopia. Irrigation (470 ± 33 mm) was measured using V-notches; rainfall did not occur, and the groundwater table was monitored daily using piezometers to estimate recharge from irrigated onion fields using the groundwater table fluctuation method. Recharge was influenced by applied irrigation amount, groundwater table depth, seasonal temperature variations, irrigation application efficiency and crop growth stages. The decreased deep percolation during the hottest periods and peak growth stages negatively influenced the reduction in groundwater decline caused by irrigation. The soil anisotropy also played a major role in the recharge amount: despite clay dominance in the topsoils, rapid groundwater table rises (0.02–0.56 m) were due to the presence of granular and blocky structures. Recharge was also influenced by irrigation efficiency, indicating higher recharge during periods of lower efficiency. The seasonal recharge was 34–46% of applied irrigation and there is much room for improving irrigation efficiency which is only 46 (±12) to 51 (±17)%.
13 Annys, S.; Van Passel, S.; Dessein, J.; Ghebreyohannes, T.; Adgo, E.; Nyssen, J. 2020. Small-scale irrigation expansion along the dam-regulated Tekeze River in northern Ethiopia. International Journal of Water Resources Development, 23p. (Online first) [doi: https://doi.org/10.1080/07900627.2020.1808446]
Farmer managed irrigation systems ; Small scale systems ; River regulation ; Dams ; Water reservoirs ; Hydropower ; Irrigated farming ; Farming systems ; Farmland ; Land tenure ; Policies ; Markets ; Models / Ethiopia / Tekeze River
(Location: IWMI HQ Call no: e-copy only Record No: H049983)
(9.58 MB)
Based on extensive field information, farmer-led small-scale irrigation systems along the dam-regulated Tekeze River is investigated and the likelihood of future irrigation expansion within the area with modelled potential is discussed, considering facilitating and hampering factors. Due to dam-induced hydrologic alterations, downstream socio-ecological systems have strongly transformed as the irrigated area has quadrupled and the post-dam potential for perennial crop cultivation has attracted numerous migrant investors to the area, inducing inequalities but also providing opportunities. Future dam construction should involve tailored policy interventions to facilitate irrigation expansion, while safeguarding equal and sustainable access to water and land.
14 Assaye, H.; Nyssen, J.; Poesen, J.; Lemma, H.; Meshesha, D. T.; Wassie, A.; Adgo, E.; Frankl, A. 2021. Curve number calibration for measuring impacts of land management in sub-humid Ethiopia. Journal of Hydrology: Regional Studies, 35:100819. [doi: https://doi.org/10.1016/j.ejrh.2021.100819]
Land management ; Subhumid zones ; Catchment areas ; Land use ; Land cover ; Farmland ; Hydrology ; Forecasting ; Models ; Rain ; Runoff ; Soil erosion ; Vegetation / Ethiopia / Lake Tana Basin / Enkulal Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050402)
https://www.sciencedirect.com/science/article/pii/S2214581821000483/pdfft?md5=811f24334ecf439a5dd45030e6fb5ebc&pid=1-s2.0-S2214581821000483-main.pdf
https://vlibrary.iwmi.org/pdf/H050402.pdf
https://vlibrary.iwmi.org/pdf/H050402.pdf
(7.40 MB) (7.40 MB)
Study Region: We investigate the event runoff response in six sub-catchments in the Lake Tana sub-basin, headwater of the Blue Nile basin, northwest Ethiopia. Steep and mountainous terrains surround floodplains, imposing runoff and soil erosion in the upper catchments and flooding and sedimentation at floodplains. This study was conducted in the upland runoff source catchments.
Study Focus: The focus is to investigate catchment characteristics that control the event runoff response in upland catchments, and how recent land management practices may have contributed to improved hydrological conditions. Event rainfall and runoff data were obtained at five-minute time steps through automated divers and tipping bucket rain gauges and related to catchment characteristics.
New Hydrological Insights for the Region: Our results show that the catchment event quickflow response was controlled by different factors of both natural and anthropogenic nature of which forest and shrubs, bund density and soil organic matter content were found to be the most important to reduce event quickflow. On the contrary, increase in cropland area caused an increase in quickflow. Through least square fitting procedure of the Natural Resources Conservation Service Curve Number method (NRCS-CN), a site specific abstraction ratio ( ) value of 0.01, rather than the commonly used 0.2 or 0.05, was found to be most appropriate for the sub-humid highlands of Ethiopia.
Study Focus: The focus is to investigate catchment characteristics that control the event runoff response in upland catchments, and how recent land management practices may have contributed to improved hydrological conditions. Event rainfall and runoff data were obtained at five-minute time steps through automated divers and tipping bucket rain gauges and related to catchment characteristics.
New Hydrological Insights for the Region: Our results show that the catchment event quickflow response was controlled by different factors of both natural and anthropogenic nature of which forest and shrubs, bund density and soil organic matter content were found to be the most important to reduce event quickflow. On the contrary, increase in cropland area caused an increase in quickflow. Through least square fitting procedure of the Natural Resources Conservation Service Curve Number method (NRCS-CN), a site specific abstraction ratio ( ) value of 0.01, rather than the commonly used 0.2 or 0.05, was found to be most appropriate for the sub-humid highlands of Ethiopia.
15 Tewabe, D.; Dessie, M.; Asmamaw, D. K.; Tamiru, E.; Adgo, E.; Nyssen, J.; Walraevens, K.; Cornelis, W. M. 2021. Comparative analysis of groundwater conditions on rain-fed and irrigated agriculture in the Upper Blue Nile Basin, Ethiopia. Journal of Hydrology: Regional Studies, 37:100916. [doi: https://doi.org/10.1016/j.ejrh.2021.100916]
Groundwater table ; Groundwater recharge ; Rainfed farming ; Irrigated farming ; Water quality ; Water levels ; Irrigation water ; Irrigation schemes ; Irrigation systems ; Wells ; Monitoring ; Comparative analysis / Ethiopia / Upper Blue Nile Basin / Koga Irrigation Scheme
(Location: IWMI HQ Call no: e-copy only Record No: H050748)
https://www.sciencedirect.com/science/article/pii/S2214581821001452/pdfft?md5=67941871048330669172ebac2f15b4c0&pid=1-s2.0-S2214581821001452-main.pdf
https://vlibrary.iwmi.org/pdf/H050748.pdf
https://vlibrary.iwmi.org/pdf/H050748.pdf
(4.82 MB) (4.82 MB)
Study region: Upper Blue Nile Basin, Ethiopia.
Study focus: This study was conducted at the Koga Irrigation Scheme in the upper Blue Nile basin (Ethiopia) to investigate the influence of irrigation activity on the groundwater system. Representative samples of six shallow wells in the irrigated fields and four shallow wells in the adjacent non-irrigated (rain-fed agricultural lands) were selected. Dipmeter and hand GPS (GARMIN 60) were used for the monitoring of water table depth and fixing the location of the wells respectively. Arc GIS 10.5 has been applied for interpolation of water table depth (WTD). Water samples were collected and analyzed in the laboratory following international standards.
New hydrological insights for the region: The result shows that irrigation contributed to the water table rises of wells located in the irrigated fields which range from 0.77 m to 0.52 m and water table drops were observed in wells located in the non-irrigated fields. Investigations on the groundwater quality (GWQ) indicated that no significant effect was observed in the irrigated and non-irrigated fields. The study shows that good irrigation water management, continuous follow-up of the groundwater table and its physico-chemical properties are essential for the sustainability of the Koga Irrigation Scheme.
Study focus: This study was conducted at the Koga Irrigation Scheme in the upper Blue Nile basin (Ethiopia) to investigate the influence of irrigation activity on the groundwater system. Representative samples of six shallow wells in the irrigated fields and four shallow wells in the adjacent non-irrigated (rain-fed agricultural lands) were selected. Dipmeter and hand GPS (GARMIN 60) were used for the monitoring of water table depth and fixing the location of the wells respectively. Arc GIS 10.5 has been applied for interpolation of water table depth (WTD). Water samples were collected and analyzed in the laboratory following international standards.
New hydrological insights for the region: The result shows that irrigation contributed to the water table rises of wells located in the irrigated fields which range from 0.77 m to 0.52 m and water table drops were observed in wells located in the non-irrigated fields. Investigations on the groundwater quality (GWQ) indicated that no significant effect was observed in the irrigated and non-irrigated fields. The study shows that good irrigation water management, continuous follow-up of the groundwater table and its physico-chemical properties are essential for the sustainability of the Koga Irrigation Scheme.
16 Wubaye, G. B.; Gashaw, T.; Worqlul, A. W.; Dile, Y. T.; Taye, Meron Teferi; Haileslassie, Amare; Zaitchik, B.; Birhan, D. A.; Adgo, E.; Mohammed, J. A.; Lebeza, T. M.; Bantider, A.; Seid, Abdulkarim; Srinivasan, R. 2023. Trends in rainfall and temperature extremes in Ethiopia: station and agro-ecological zone levels of analysis. Atmosphere, 14(3):483. (Special issue: Water Management and Crop Production in the Face of Climate Change) [doi: https://doi.org/10.3390/atmos14030483]
Extreme weather events ; Rainfall ; Temperature ; Trends ; Meteorological stations ; Agroecological zones ; Climate change adaptation ; Precipitation ; Spatial distribution ; Time series analysis / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H051768)
https://www.mdpi.com/2073-4433/14/3/483/pdf?version=1678174504
https://vlibrary.iwmi.org/pdf/H051768.pdf
https://vlibrary.iwmi.org/pdf/H051768.pdf
(9.01 MB) (9.01 MB)
Climate extreme events have been observed more frequently since the 1970s throughout Ethiopia, which adversely affects the socio-economic development of the country, as its economy depends on agriculture, which, in turn, relies heavily on annual and seasonal rainfall. Climate extremes studies conducted in Ethiopia are mainly limited to a specific location or watershed, making it difficult to have insights at the national level. The present study thus aims to examine the observed climate extreme events in Ethiopia at both station and agro-ecological zone (AEZ) levels. Daily rainfall and temperature data for 47 and 37 stations, respectively (1986 up to 2020), were obtained from the National Meteorology Agency (NMA). The Modified Mann–Kendall (MMK) trend test and the Theil–Sen slope estimator were employed to estimate the trends in rainfall and temperature extremes. This study examines trends of 13 temperature and 10 rainfall extreme indices using RClimDex in R software. The results revealed that most of the extreme rainfall indices showed a positive trend in the majority of the climate stations. For example, an increase in consecutive dry days (CDD), very heavy rainfall days (R20), number of heavy rainfall days (R10) and consecutive wet days (CWD) were exhibited in most climate stations. In relation to AEZs, the greater number of extreme rainfall indices illustrated an upward trend in cool and sub-humid, cool and humid, and cool and moist AEZs, a declining trend in hot arid AEZ, and equal proportions of increasing and decreasing trends in warm semi-arid AEZs. Concerning extreme temperature indices, the result indicated an increasing trend of warm temperature extreme indices and a downward trend of cold temperature extreme indices in most of the climate stations, indicating the overall warming and dryness trends in the country. With reference to AEZs, an overall warming was exhibited in all AEZs, except in the hot arid AEZ. The observed trends in the rainfall and temperature extremes will have tremendous direct and indirect impacts on agriculture, water resources, health, and other sectors in the country. Therefore, the findings suggest the need for identifying and developing climate change adaptation strategies to minimize the ill effects of these extreme climate events on the social, economic, and developmental sectors.
17 Gashaw, T.; Wubaye, G. B.; Worqlul, A. W.; Dile, Y. T.; Mohammed, J. A.; Birhan, D. A.; Tefera, G. W.; van Oel, P. R.; Haileslassie, Amare; Chukalla, A. D.; Taye, Meron Teferi; Bayabil, H. K.; Zaitchik, B.; Srinivasan, R.; Senamaw, A.; Bantider, A.; Adgo, E.; Seid, Abdulkarim. 2023. Local and regional climate trends and variabilities in Ethiopia: implications for climate change adaptations. Environmental Challenges, 13:100794. [doi: https://doi.org/10.1016/j.envc.2023.100794]
Climate change adaptation ; Climate variability ; Trends ; Strategies ; Rainfall ; Temperature ; Agroecological zones ; Meteorological stations ; Spatial distribution / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052409)
https://www.sciencedirect.com/science/article/pii/S2667010023001178/pdfft?md5=7a942050dc761a0e0ab04c909ca6637b&pid=1-s2.0-S2667010023001178-main.pdf
https://vlibrary.iwmi.org/pdf/H052409.pdf
https://vlibrary.iwmi.org/pdf/H052409.pdf
(4.10 MB) (4.10 MB)
Ethiopia is experiencing considerable impact of climate change and variability in the last five decades. Analyzing climate trends and variability is essential to develop effective adaptation strategies, particularly for countries vulnerable to climate change. This study analyzed trends and variabilities of climate (rainfall, maximum temperature (Tmax), and minimum temperature (Tmin)) at local and regional scales in Ethiopia. The local analysis was carried out considering each meteorological station, while the regional analyses were based on agroecological zones (AEZs). This study used observations from 47 rainfall and 37 temperature stations obtained from the Ethiopian Meteorological Institute (EMI) for the period of 1986 to 2020. The Modified Mann-Kendall (MMK) trend test and Theil Sen’s slope estimator were used to analyze the trends and magnitudes of change, respectively, in rainfall as well as temperature. The coefficient of variation (CV) and standardized anomaly index (SAI) were also employed to evaluate rainfall and temperature variabilities. The local level analysis revealed that Bega (dry season), Kiremt (main rainy season), and annual rainfall showed increasing trend, albeit no significant, in most stations, but the rainfall in Belg (small rainy) season showed a non-significant decreasing trend. The regional levels analysis also indicated an increasing trend of Bega, Kiremt, and annual rainfall in most AEZs, while Belg rainfall showed a decreasing trend in the greater number of AEZs. The result of both local and regional levels of analysis discerned a spatially and temporally more homogeneous warming trend. Both Tmax and Tmin revealed an increasing trend in annual and seasonal scales at most meteorological stations. Likewise, an increase was recorded for mean Tmax and Tmin in entire/most AEZs. The observed trends and variabilities of rainfall and temperature have several implications for climate change adaptations. For example, the decrease in Belg rainfall in most AEZs would have a negative impact on areas that heavily depend on Belg season’s rainfall for crop production. Some climate adaptation options include identifying short maturing crop varieties, soil moisture conservation, and supplemental irrigation of crops using harvested water during the main rainy season. Conversely, since the first three months of Bega season (October to December) are crop harvest season in most parts of Ethiopia, the increase in Bega rainfall would increase crop harvest loss, and hence, early planting date and identifying short maturing crops during the main rainy season are some climate adaptation strategies. Because of the increase in temperature, water demand for irrigation during Bega season will increase due to increased evapotranspiration. On the other hand, the increase in Kiremt rainfall can be harvested and used for supplemental irrigation during Bega as well as the small rainy season, particularly for early planting. In view of these findings, it is imperative to develop and implement effective climate-smart agricultural strategies specific to each agro-ecological zone (AEZ) to adapt to rainfall and temperature changes and variabilities.
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