Your search found 19 records
1 Worqlul, A. W.; Jeong, J.; Dile, Y. T.; Osorio, J.; Schmitter, Petra; Gerik, T.; Srinivasan, R.; Clark, N. 2017. Assessing potential land suitable for surface irrigation using groundwater in Ethiopia. Applied Geography, 85:1-13. [doi: https://doi.org/10.1016/j.apgeog.2017.05.010]
Surface irrigation ; Groundwater recharge ; Groundwater irrigation ; Water storage ; Geographical information systems ; Land suitability ; Land use ; Irrigated land ; Agroindustry ; Soil texture ; Slopes ; Rain ; Evapotranspiration ; Water requirements ; Water resources ; Water availability ; River basins ; Population density ; Mapping ; Farmer-led irrigation ; Crops / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H048151)
http://www.sciencedirect.com/science/article/pii/S0143622816306269/pdfft?md5=d81ce4d77a5a37854e1918796d7b3995&pid=1-s2.0-S0143622816306269-main.pdf
https://vlibrary.iwmi.org/pdf/H048151.pdf
https://vlibrary.iwmi.org/pdf/H048151.pdf
(5.35 MB)
Although Ethiopia has abundant land for irrigation, only a fraction of its potential land is being utilized. This study evaluates suitability of lands for irrigation using groundwater in Ethiopia using GIS-based Multi-Criteria Evaluation (MCE) techniques in order to enhance the country's agricultural industry. Key factors that significantly affect irrigation suitability evaluated in this study include physical land features (land use, soil, and slope), climate (rainfall and evapotranspiration), and market access (proximity to roads and access to market). These factors were weighted using a pair-wise comparison matrix, then reclassified and overlaid to identify suitable areas for groundwater irrigation using a 1-km grid. Groundwater data from the British Geological Survey were used to estimate the groundwater potential, which indicates the corresponding irrigation potential for major crops. Results indicated that more than 6 million ha of land are suitable for irrigation in Ethiopia. A large portion of the irrigable land is located in the Abbay, Rift Valley, Omo Ghibe, and Awash River basins. These basins have access to shallow groundwater (i.e., depth of groundwater less than 20 m from the surface) making it easier to extract. The comparison between available groundwater and total crop water requirements indicate that groundwater alone may not be sufficient to supply all suitable land. The study estimates that only 8% of the suitable land can be irrigated with the available shallow groundwater. However, groundwater is a viable option for supplementing surface water resources for irrigation in several basins in the country.
2 Dile, Y. T.; Tekleab, S.; Ayana, E. K.; Gebrehiwot, S. G.; Worqlul, A. W.; Bayabil, H. K.; Yimam, Y. T.; Tilahun, S. A.; Daggupati, P.; Karlberg, L.; Srinivasan, R. 2018. Advances in water resources research in the Upper Blue Nile Basin and the way forward: a review. Journal of Hydrology, 560:407-423. [doi: https://doi.org/10.1016/j.jhydrol.2018.03.042]
Water resources ; Research ; Water conservation ; Soil conservation ; Erosion ; Climate change ; Land use ; Catchment areas ; Water balance ; Hydrology ; Models ; Economic development ; Agriculture ; Remote sensing / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048798)
https://www.sciencedirect.com/science/article/pii/S0022169418302087/pdfft?md5=fd653f0a22b3bbc8ecfa4c346eb5cfc9&pid=1-s2.0-S0022169418302087-main.pdf
https://vlibrary.iwmi.org/pdf/H048798.pdf
https://vlibrary.iwmi.org/pdf/H048798.pdf
(1.32 MB) (1.32 MB)
The Upper Blue Nile basin is considered as the lifeline for ~250 million people and contributes ~50 Gm3 / year of water to the Nile River. Poor land management practices in the Ethiopian highlands have caused a significant amount of soil erosion, thereby threatening the productivity of the Ethiopian agricultural system, degrading the health of the aquatic ecosystem, and shortening the life of downstream reservoirs. The Upper Blue Nile basin, because of limited research and availability of data, has been considered as the "great unknown." In the recent past, however, more research has been published. Nonetheless, there is no state-of-the-art review that presents research achievements, gaps and future directions. Hence, this paper aims to bridge this gap by reviewing the advances in water resources research in the basin while highlighting research needs and future directions. We report that there have been several research projects that try to understand the biogeochemical processes by collecting information on runoff, groundwater recharge, sediment transport, and tracers. Different types of hydrological models have been applied. Most of the earlier research used simple conceptual and statistical approaches for trend analysis and water balance estimations, mainly using rainfall and evapotranspiration data. More recent research has been using advanced semi-physically/physically based distributed hydrological models using high-resolution temporal and spatial data for diverse applications. We identified several research gaps and provided recommendations to address them. While we have witnessed advances in water resources research in the basin, we also foresee opportunities for further advancement. Incorporating the research findings into policy and practice will significantly benefit the development and transformation agenda of the Ethiopian government.
3 Gashaw, T.; Tulu, T.; Argaw, M.; Worqlul, A. W.; Tolessa, T.; Kindu, M. 2018. Estimating the impacts of land use/land cover changes on ecosystem service values: the case of the Andassa Watershed in the Upper Blue Nile Basin of Ethiopia. Ecosystem Services, 31(Part A):219-228. [doi: https://doi.org/10.1016/j.ecoser.2018.05.001]
Ecosystem services ; Economic value ; Land use ; Land cover change ; Estimation ; Watersheds ; Cultivated land ; Forest land ; Scrublands ; Grasslands ; River basins ; Models / Ethiopia / Upper Blue Nile Basin / Andassa Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048818)
(1.40 MB)
Estimating the impacts of land use/land cover (LULC) changes in Ecosystem Service Values (ESV) is indispensable to provide public awareness about the status of ESV, and to help in policy-making processes. This study was intended to estimate the impacts of LULC changes on ESV in the Andassa watershed of the Upper Blue Nile basin over the last three decades (1985–2015), and to predict the ESV changes in 2045. The hybrid land use classification technique for classifying Landsat images, the Cellular-Automata Markov (CA-Markov) model for LULC prediction, and the modified ecosystem service value coefficients for estimating ESV were employed. Our findings revealed that there was a continues expansions of cultivated land and built-up area, and withdrawing of forest, shrubland and grassland during the 1985–2015 periods, which are expected to continue for the next three decades. Consequently, the total ESV of the watershed has declined from US$26.83 106 in 1985 to US$22.58 106 in 2000 and to US $21.00 106 in 2015 and is expected to further reduce to US$17.94 106 in 2030 and to US$15.25 106 in 2045. The impacts of LULC changes on the specific ecosystem services are also tremendous.
4 Worqlul, A. W.; Dile, Y. T.; Jeong, J.; Adimassu, Zenebe; Lefore, Nicole; Gerik, T.; Srinivasan, R.; Clarke, N. 2019. Effect of climate change on land suitability for surface irrigation and irrigation potential of the shallow groundwater in Ghana. Computers and Electronics in Agriculture, 157: 110-125. [doi: https://doi.org/10.1016/j.compag.2018.12.040]
Climate change ; Land suitability ; Land use ; Irrigation methods ; Surface irrigation ; Groundwater management ; Water resources ; Surface water ; GIS ; Slope ; Soils ; Socioeconomic environment ; Population density ; Rainfall ; Temperature ; Evapotranspiration / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H049052)
https://reader.elsevier.com/reader/sd/pii/S0168169918311426?token=D47C9342836EF05EF9C7A103181929ACB8DDE1F80AD6AF06C2A5B98E687E907761A212B911EFC4AC23D7985048ACB910
https://vlibrary.iwmi.org/pdf/H049052.pdf
https://vlibrary.iwmi.org/pdf/H049052.pdf
(6.84 MB)
Estimating the potential land resources suitable for irrigation and evaluating the possible impact of climate change on land suitability is essential for planning a sustainable agricultural system. This study applied a GIS-based Multi-Criteria Evaluation (MCE) technique to evaluate the suitability of land for irrigation in Ghana for a baseline period (1990 to 2010) and future time horizons 2050s (2041 to 2060) and 2070s (2061 to 2080). Key factors considered to evaluate the suitability of the land for irrigation include biophysical features (such as climate, land use, soil, and slope) and socioeconomic factors (such as proximity to roads and population density). These factors were weighted using a pairwise comparison matrix then reclassified and overlaid on a 30 m grid to estimate the irrigation potential of the country. Groundwater data from the British Geological Survey (BGS) were superimposed onto the land suitability map layer to evaluate the irrigation potential and the accessibility of shallow groundwater with simple water lifting technologies. Downscaled and bias-corrected future climate data from HadGEM2-ES under Representative Concentration Pathways (RCP) 4.5 emission scenario were used to represent the future climate horizon. Due to climate change, on average, rainfall will increase by 15 mm and 20 mm from the baseline period in the 2050s and 2070s, respectively. The average temperature shows a consistent increase in the majority of Ghana and a higher rate of increase is expected in the 2070s. Consequently, the rising temperature will increase the potential evapotranspiration by 6.0% and 7.6% in the 2050s and 2070s, respectively. The suitability analysis indicates that approximately 9% of the country is suitable for surface irrigation under the baseline period. A large portion of the potential land is located in the southwestern part of the country. The potential suitable land has an average groundwater access of 12 m from the surface with an average borehole potential yield of 2.5 L/second, which makes it favorable for utilization of simple water lifting technologies. Due to climate change, 9.5% of the suitable land will become unfavorable for irrigation in 2050s, and it is expected to reach 17% in 2070s.
5 Assefa, T.; Jha, M.; Reyes, M.; Tilahun, S.; Worqlul, A. W.. 2019. Experimental evaluation of conservation agriculture with drip irrigation for water productivity in Sub-Saharan Africa. Water, 11(3):1-13. [doi: https://doi.org/10.3390/w11030530]
Conservation agriculture ; Water productivity ; Drip irrigation ; Evaluation ; Water management ; Irrigation water ; Water use ; Sustainable agriculture ; Intensification ; Crop yield ; Farmers / Africa South of Sahara / Ethiopia / Ghana / Dangishita / Robit / Yemu
(Location: IWMI HQ Call no: e-copy only Record No: H049153)
(10.10 MB) (10.1 MB)
A field-scale experimental study was conducted in Sub-Saharan Africa (Ethiopia and Ghana) to examine the effects of conservation agriculture (CA) with drip irrigation system on water productivity in vegetable home gardens. CA here refers to minimum soil disturbance (no-till), year-round organic mulch cover, and diverse cropping in the rotation. A total of 28 farmers (13 farmers in Ethiopia and 15 farmers in Ghana) participated in this experiment. The experimental setup was a paired ‘t’ design on a 100 m2 plot; where half of the plot was assigned to CA and the other half to conventional tillage (CT), both under drip irrigation system. Irrigation water use and crop yield were monitored for three seasons in Ethiopia and one season in Ghana for vegetable production including garlic, onion, cabbage, tomato, and sweet potato. Irrigation water use was substantially lower under CA, 18% to 45.6%, with a substantial increase in crop yields, 9% to about two-fold, when compared with CT practice for the various vegetables. Crop yields and irrigation water uses were combined into one metric, water productivity, for the statistical analysis on the effect of CA with drip irrigation system. One-tailed paired ‘t’ test statistical analysis was used to examine if the mean water productivity in CA is higher than that of CT. Water productivity was found to be significantly improved (a = 0.05) under the CA practice; 100%, 120%, 222%, 33%, and 49% for garlic, onion, tomato, cabbage, and sweet potato respectively. This could be due to the improvement of soil quality and structure due to CA practice, adding nutrients to the soil and sticking soil particles together (increase soil aggregates). Irrigation water productivity for tomato under CA (5.17 kg m-3 in CA as compared to 1.61 kg m-3 in CT) is found to be highest when compared to water productivity for the other vegetables. The mulch cover provided protection for the tomatoes from direct contact with the soil and minimized the chances of soil-borne diseases. Adapting to CA practices with drip irrigation in vegetable home gardens is, therefore, a feasible strategy to improve water use efficiency, and to intensify crop yield, which directly contributes towards the sustainability of livelihoods of smallholder farmers in the region.
6 Worqlul, A. W.; Dile, Y. T.; Schmitter, Petra; Jeong, J.; Meki, M. N.; Gerik, T. J.; Srinivasan, R.; Lefore, Nicole; Clarke, N. 2019. Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia. Agricultural Water Management, 226:105767. [doi: https://doi.org/10.1016/j.agwat.2019.105767]
Water resources ; Assessment ; Agricultural production ; Vegetables ; Crop yield ; Tomatoes ; Onions ; Irrigation water ; Rain ; Groundwater recharge ; Watersheds ; Water use efficiency ; Fertilizer application ; Farmers ; Farmer-led irrigation ; Models / Ethiopia / Upper Blue Nile Basin / Robit Watershed / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049376)
https://www.sciencedirect.com/science/article/pii/S0378377418314021/pdfft?md5=769bfc34b80853a9a6b06c0b86106dda&pid=1-s2.0-S0378377418314021-main.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
(2.00 MB) (2.00 MB)
The vast majority of farmers in sub-Saharan Africa depend on rainfed agriculture for food production and livelihood. Various factors including but not limited to rainfall variability, land degradation, and low soil fertility constrain agricultural productivity in the region. The objectives of this study were to 1) estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia during the dry season so as to expand food supply by growing vegetables, and 2) understand the gaps and constraints of vegetable production. The case studies were conducted in the Robit and Dangishta watersheds of the Upper Blue Nile Basin, Ethiopia. To document farmers’ cropping practices, field-level data were collected from 36 households who had been cultivating tomato (Solanum lycopersicum L.) and onion (Allium cepa L.) during the dry season (November – April). Two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) – were respectively used to assess impacts of SSI at the watershed and field-scale levels. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at the watershed scale. The field-scale analysis in the Robit watershed indicated that optimal tomato yield could be obtained with 500 mm of water and 200 to 250 kg/ha of urea applied with 50 kg/ ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained with 400 mm of water and 120 to 180 kg/ha of urea applied with 50 kg/ha of DAP. The field-scale simulation indicated that the average shallow groundwater recharge (after accounting for other groundwater users such as household and livestock use) was not sufficient to meet tomato and onion water demand in the dry season (October to April). The fieldscale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (60% for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could optimize irrigation water for vegetable production by reducing soil evaporation and thereby increasing water availability in the crop root zone.
7 Belay, S. A.; Schmitter, Petra; Worqlul, A. W.; Steenhuis, T. S.; Reyes, M. R.; Tilahun, S. A. 2019. Conservation agriculture saves irrigation water in the dry monsoon phase in the Ethiopian highlands. Water, 11(10):1-16. [doi: https://doi.org/10.3390/w11102103]
Conservation agriculture ; Irrigation water ; Arid climate ; Monsoon climate ; Highlands ; Conventional tillage ; Irrigation scheduling ; Farmers ; Irrigation practices ; Water use efficiency ; Irrigated farming ; Crop yield ; Onions ; Garlic ; Farmer-led irrigation ; Soil moisture / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H049377)
(1.45 MB) (1.45 MB)
Water resources in sub-Saharan Africa are more overstressed than in many other regions of the world. Experiments on commercial farms have shown that conservation agriculture (CA) can save water and improve the soil. Nevertheless, its benefits on smallholder irrigated farms have not been adequately investigated, particularly in dry monsoon phase in the Ethiopian highlands. We investigated the effect of conservation agriculture (grass mulch cover and no-tillage) on water-saving on smallholder farms in the Ethiopian highlands. Irrigated onion and garlic were grown on local farms. Two main factors were considered: the first factor was conservation agriculture versus conventional tillage, and the second factor was irrigation scheduling using reference evapotranspiration (ETo) versus irrigation scheduling managed by farmers. Results showed that for both onion and garlic, the yield and irrigation water use efficiency (IWUE) was over 40% greater for CA than conventional tillage (CT). The soil moisture after irrigation was higher in CA compared with CT treatment while CA used 49 mm less irrigation water. In addition, we found that ETo-based irrigation was superior to the farmers’ irrigation practices for both crops. IWUE was lower in farmers irrigation practices due to lower onion and garlic yield responses to overirrigation and greater water application variability.
8 Assefa, T.; Jha, M.; Reyes, M.; Worqlul, A. W.; Doro, L.; Tilahun, S. 2020. Conservation agriculture with drip irrigation: effects on soil quality and crop yield in Sub-Saharan Africa. Journal of Soil and Water Conservation, 75(2):209-217. [doi: https://doi.org/10.2489/jswc.75.2.209]
Conservation agriculture ; Drip irrigation ; Soil quality ; Crop yield ; Forecasting ; Agricultural policy ; Conventional tillage ; Crop production ; Environmental modelling / Africa South of Sahara / United Republic of Tanzania / Ghana / Ethiopia / Dangishita / Robit / Yemu / Mkindo
(Location: IWMI HQ Call no: e-copy only Record No: H049628)
(0.66 MB)
The traditional agriculture production system in sub-Saharan Africa (SSA) caused significant soil erosion and degradation of soil quality. In addition, dependability of rainfall for irrigation needs limits the crop production. Advanced agricultural practices are thus needed at the local level to sustain the livelihood of smallholder farmers in the region. In this study, conservation agriculture (CA) practice with drip irrigation technology was compared (using field experiments and watershed modeling) with the traditional conventional tillage (CT) practice for its potential in improving soil quality and crop productivity in the region. Biophysical data were collected (2015 to 2017) from a total of 43 paired plots (CA and CT) at four study sites in SSA: Dangishita and Robit in Ethiopia, Yemu in Ghana, and Mkindo in Tanzania. The Agricultural Policy/Environmental eXtender (APEX) model was calibrated and validated with reasonable efficiency in simulating crop yields for both CA and CT practices; average PBIAS =±12% and =±11%, for CA and CT. The impact of the CA system on soil quality (soil carbon [C] and nitrogen [N]) was analyzed based on the well-tested model prediction results. The total C and N were increased under CA across the study sites on average by 6% and 4.1%, when compared to CT over the study period. Both the experiment and model prediction showed that crop yield was significantly improved by CA—on average 37.4% increases across the sites when compared to CT. Conservation agriculture with drip irrigation was an efficient local strategy to improve crop production in the region while enhancing the ecosystem.
9 Belay, S. A.; Assefa, T. T.; Prasad, P. V. V.; Schmitter, Petra; Worqlul, A. W.; Steenhuis, T. S.; Reyes, M. R.; Tilahun, S. A. 2020. The response of water and nutrient dynamics and of crop yield to conservation agriculture in the Ethiopian highlands. Sustainability, 12(15):5989. [doi: https://doi.org/10.3390/su12155989]
Conservation agriculture ; Water use ; Nutrient availability ; Crop yield ; Highlands ; Supplemental irrigation ; Conventional tillage ; Irrigation water ; Water management ; Crop management ; Pepper ; Growth period ; Fertilizers ; Phosphorus ; Nitrogen ; Leachates ; Rain ; Runoff ; Evapotranspiration / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H049873)
(2.48 MB) (2.48 MB)
Smallholder agriculture constitutes the main source of livelihood for the Ethiopian rural community. However, soil degradation and uneven distribution of rainfall have threatened agriculture at present. This study is aimed at investigating the impacts of conservation agriculture on irrigation water use, nutrient availability in the root zone, and crop yield under supplementary irrigation. In this study, conservation agriculture (CA), which includes minimum soil disturbance, grass mulch cover, and crop rotation, was practiced and compared with conventional tillage (CT). We used two years’ (2018 and 2019) experimental data under paired-t design in the production of a local variety green pepper (Capsicum annuum L.). The results showed that CA practices significantly (a = 0.05) reduced irrigation water use (13% to 29%) and runoff (29% to 51%) while it increased percolated water in the root zone (27% to 50%) when compared with CT practices under the supplementary irrigation phase. In addition, CA significantly decreased NO3-N in the leachate (14% to 44%) and in the runoff (about 100%), while PO4-P significantly decreased in the leachate (33% to 50%) and in the runoff (16%) when compared with CT. Similarly, CA decreased the NO3-N load in the leachate and in the runoff, while the PO4-P load increased in the leachate but decreased in the runoff. The yield return that was achieved under CA treatment was 30% higher in 2018 and 10% higher in 2019 when compared with the CT. This research improves our understanding of water and nutrient dynamics in green pepper grown under CA and CT. Use of CA provides opportunities to optimize water use by decreasing irrigation water requirements and optimize nutrient use by decreasing nutrient losses through the runoff and leaching.
10 Dile, Y. T.; Ayana, E. K.; Worqlul, A. W.; Xie, H.; Srinivasan, R.; Lefore, N.; You, L.; Clarke, N. 2020. Evaluating satellite-based evapotranspiration estimates for hydrological applications in data-scarce regions: a case in Ethiopia. Science of the Total Environment, 743:140702. [doi: https://doi.org/10.1016/j.scitotenv.2020.140702]
Evapotranspiration ; Hydrology ; Agricultural landscape ; Satellite observation ; Remote sensing ; Water management ; Sustainability ; River basins ; Stream flow ; Land management ; Land use ; Soil moisture ; Grasslands ; Models ; Uncertainty ; Forests / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H049976)
https://www.sciencedirect.com/science/article/pii/S0048969720342248/pdfft?md5=33436fc788bb7601053c74729cab3e05&pid=1-s2.0-S0048969720342248-main.pdf
https://vlibrary.iwmi.org/pdf/H049976.pdf
https://vlibrary.iwmi.org/pdf/H049976.pdf
(11.60 MB) (11.6 MB)
Water resource development opens up opportunities for improving smallholder farmer livelihoods in sub-Saharan Africa; however, implementation of water resource interventions to ensure sustainability hinges on the availability of sufficient quantity and quality data for monitoring, analysis and planning. Such data is often acquired through instrumentation of water resources (e.g. stream flow monitoring) or the use of hydrological models. In sub-Saharan Africa, data scarcity has limited the ability to monitor and make appropriate decisions for water resource allocation and use. Data derived from remote sensing has been considered a viable option to fill this gap; however, there is limited research in the region that evaluate the quality of the remotely sensed based datasets. This study evaluated actual evapotranspiration (AET) estimates derived from Advanced Very High Resolution Radiometer (AVHRR AET) images and Moderate Resolution Imaging Spectrometer (MOD16 AET) images using estimates from a grid-based Soil and Water Assessment Tool (SWAT). The SWAT model was set up for the entire country of Ethiopia, and calibrated and validated using observed streamflow at several meso-scale watersheds in which satisfactory model performance was obtained. AET estimates from the calibrated and validated SWAT model were then used to evaluate remotely sensed based AET for three landscapes. The AVHRR AET better agreed with the SWAT-simulated AET than the MOD16 AET, although the AVHRR AET overestimated the SWAT-simulated AET in all of the landscapes. Both remotely sensed AET products showed better agreement with the SWAT-simulated AET over agriculture dominated landscapes compared to grassland and forest dominated landscapes. The findings of the study suggest that remotely sensed based AET may help to fine-tune hydrological models in agricultural landscapes in data-scarce regions to improve studies on the impacts of water management interventions aiming to ensure environmental sustainability while enhancing agricultural production, and household income and nutrition.
11 Alemu, M. L.; Worqlul, A. W.; Zimale, F. A.; Tilahun, S. A.; Steenhuis, S. 2020. Water balance for a tropical lake in the volcanic highlands: Lake Tana, Ethiopia. Water, 12(10):2737. (Special issue: Hydrology and Sedimentology of Hilly and Mountainous Landscapes) [doi: https://doi.org/10.3390/w12102737]
Water balance ; Lakes ; Rivers ; Water levels ; Runoff ; Water loss ; Evaporation ; Irrigation ; Precipitation ; Weather data ; Rain gauges ; Watersheds ; Groundwater ; Highlands ; Models / Ethiopia / Lake Tana / Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050064)
(4.57 MB) (4.57 MB)
Lakes hold most of the freshwater resources in the world. Safeguarding these in a changing environment is a major challenge. The 3000 km2 Lake Tana in the headwaters of the Blue Nile in Ethiopia is one of these lakes. It is situated in a zone destined for rapid development including hydropower and irrigation. Future lake management requires detailed knowledge of the water balance of Lake Tana. Since previous water balances varied greatly this paper takes a fresh look by calculating the inflow and losses of the lake. To improve the accuracy of the amount of precipitation falling on the lake, two new rainfall stations were installed in 2013. The Climate Hazards Group Infrared Precipitation Version two (CHIRPS-v2) dataset was used to extend the data. After reviewing all the previous studies and together with our measurements, it was found that the period of 1990–1995 likely had the most accurate gauged discharge data. During some months in this period, the lake water balance was negative. Since the river inflow to the lake cannot be negative, water was either lost from the lake via the subsurface through faults, or the outflow measurements were systematically underestimated. Based on the evaporation rate of 1650 mm, we found that unaccounted loss was 0.6 km3 a-1, equivalent to 20 cm of water over the lake area each year. This implies the need for reliable rainfall data and improved river discharge measurements over a greater portion of the basin both entering and exiting the lake. Also, integrated hydrological and geologic investigations are needed for a better understanding of the unaccounted water losses and quantifying the amount of subsurface flow leaving the lake.
12 Xie, H.; You, L.; Dile, Y. T.; Worqlul, A. W.; Bizimana, J.- C.; Srinivasan, R.; Richardson, J. W.; Thomas, G.; Neville, C. 2021. Mapping development potential of dry-season small-scale irrigation in Sub-Saharan African countries under joint biophysical and economic constraints - an agent-based modeling approach with an application to Ethiopia. Agricultural Systems, 186:102987. [doi: https://doi.org/10.1016/j.agsy.2020.102987]
Irrigation systems ; Small scale systems ; Dry season ; Agricultural development ; Water availability ; Irrigation water ; Water scarcity ; Environmental factors ; Economic aspects ; Crop yield ; Technology ; Geographical information systems ; Models ; Uncertainty / Africa South of Sahara / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H050097)
https://www.sciencedirect.com/science/article/pii/S0308521X20308489/pdfft?md5=ccefdf32598d6ea8bc5b61f1d012b437&pid=1-s2.0-S0308521X20308489-main.pdf
https://vlibrary.iwmi.org/pdf/H050097.pdf
https://vlibrary.iwmi.org/pdf/H050097.pdf
(4.40 MB) (4.40 MB)
Sub-Saharan Africa has long been beset with food insecurity. Investment in small-scale irrigation may provide a solution to address the challenge by extending crop production into the dry season. We present an agent-based modeling system to assess the potential of dry-season small-irrigation development in Sub-Saharan Africa with an application to Ethiopia. We identify significant potential for investing in dry-season small-scale irrigation in Ethiopia and map geographic domains with highest investment opportunities.
13 Worqlul, A. W.; Dile, Y. T.; Schmitter, Petra; Bezabih, M.; Adie, A.; Bizimana, J.-C.; Srinivasan, R.; Lefore, N.; Clarke, N. 2021. Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia. Agricultural Water Management, 254:106973. [doi: https://doi.org/10.1016/j.agwat.2021.106973]
Small scale farming ; Fodder ; Livestock feed ; Nutrition ; Assessment ; Irrigation ; Small scale systems ; Water use efficiency ; Fertilizer application ; Rain ; Runoff ; Groundwater ; Water stress ; Forage yield ; Pennisetum purpureum ; Lathyrus cicera ; Oats ; Farmers ; Watersheds / Africa South of Sahara / Ethiopia / Robit Watershed / Lemo Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050449)
(3.69 MB)
Livestock is an integral part of the agricultural system in sub-Saharan Africa, serving as a food source, income, fertilizer, and power for farming and transportation. However, the productivity of the livestock system has been hampered due to a lack of sufficient quantity and quality feed. This study evaluates the gaps and constraints of fodder and nutritional potential for livestock feed using small-scale irrigation (SSI). The study comprised of 30 randomly selected farmers from two different ecological zones in Ethiopia. Half of the farmers cultivated Napier grass (Pennisetum purpureum) in the Robit watershed in northern Ethiopia, and the other half cultivated mixed vetch (Lathyrus cicera) and oats (Avena sativa) in Lemo watershed in southern Ethiopia. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) were applied in an integrated manner to assess the impacts of SSI at the watershed and field-scale levels, respectively. The watershed-scale analysis showed that there is a substantial amount of surface runoff and shallow groundwater recharge that could be used for dry season fodder production using irrigation. Field data calibrated APEX model indicated that Napier yield could be maximized with 550 mm of water in Robit watershed. While in the Lemo watershed, maximum vetch and oats yield may be achieved with 250 mm of water. The major constraints for Napier and oats production in the study sites were soil fertility, especially nitrogen and phosphorus, and vetch production was limited by high temperature. Fodder samples were collected at the time of harvest to evaluate feed quality. The nutritional analysis indicated that Napier grass has a higher dry matter and ash (mineral) content compared to oats and vetch. However, vetch has higher crude protein content (18%) compared to Napier (10%) and oats (6%). Overall the study indicated that cultivating vetch provided superior performance in terms of providing quality feed and environmental services.
14 Belay, S. A.; Assefa, T. T.; Worqlul, A. W.; Steenhuis, T. S.; Schmitter, Petra; Reyes, M. R.; Prasad, P. V. V.; Tilahun, S. A. 2022. Conservation and conventional vegetable cultivation increase soil organic matter and nutrients in the Ethiopian highlands. Water, 14(3):476. (Special issue: Hydrology and Sedimentology of Hilly and Mountainous Landscapes) [doi: https://doi.org/10.3390/w14030476]
Conservation agriculture ; Conventional tillage ; Soil organic matter ; Soil fertility ; Nutrients ; Highlands ; Vegetable crops ; Irrigation water / Africa South of Sahara / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H051088)
https://www.mdpi.com/2073-4441/14/3/476/pdf?version=1644302965
https://vlibrary.iwmi.org/pdf/H051088.pdf
https://vlibrary.iwmi.org/pdf/H051088.pdf
(1.69 MB) (1.69 MB)
Agriculture in Africa is adversely affected by the loss of soil fertility. Conservation agriculture (CA) was introduced to curb the loss of soil fertility and water shortages and improve crop productivity. However, information on how CA practices enhance soil quality and nutrients is scarce in the sub-Saharan Africa context. The objective of this study was to investigate the effects of CA and conventional tillage (CT) on soil organic matter and nutrients under irrigated and rainfed vegetable on-farm production systems. During the dry and wet monsoon phases in the northern Ethiopian Highlands, a four-year experiment with CA and CT was carried out on ten vegetable farms under rainfed and irrigated conditions. Although the increase in concentration of organic matter in CA was generally slightly greater than in CT, the difference was not significant. The average organic matter content in the top 30 cm for both treatments increased significantly by 0.5% a-1 from 3% to almost 5%. The increase was not significant for the 30–60 cm depth. The total nitrogen and available phosphorus concentrations increased proportionally to the organic matter content. Consequently, the extended growing season, applying fertilizers and livestock manure, and not removing the crop residue increased the nutrient content in both CA and CT. The increase in CA was slightly greater because the soil was not tilled, and hay was applied as a surface cover. Although CA increased soil fertility, widespread adoption will depend on socioeconomic factors that determine hay availability as a soil cover relative to other competitive uses.
15 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.
16 Gashaw, T.; Worqlul, A. W.; Lakew, Haileyesus; Taye, Meron Teferi; Seid, Abdulkarim; Haileslassie, Amare. 2023. Evaluations of satellite/reanalysis rainfall and temperature products in the Bale Eco-Region (southern Ethiopia) to enhance the quality of input data for hydro-climate studies. Remote Sensing Applications: Society and Environment, 31:100994. [doi: https://doi.org/10.1016/j.rsase.2023.100994]
Rainfall ; Temperature ; Models ; Evaluation ; Satellite observation ; Hydroclimate ; Precipitation ; Agroecological zones ; Meteorological stations ; Estimation / Ethiopia / Bale Eco-Region
(Location: IWMI HQ Call no: e-copy only Record No: H051974)
(7.50 MB)
The sparse distribution and lack of meteorological stations due to deficit infrastructure in developing countries is one of the limiting factors for hydro-climate studies, and dependency on globally available data is often prone to various level of errors. Thus, this study aimed to evaluate the performance of satellite/reanalysis rainfall and temperature products in the Bale Eco-Region (BER) in Southern Ethiopia. This study evaluated performances of three rainfall products such as the Climate Hazards Group Infrared Precipitation with Stations, version 2.0 (CHIRPS v2.0), Tropical Applications of Meteorology using SATellite and ground-based observations, version 3.1 (TAMSAT v3.1) and Multi-Source Weighted-Ensemble Precipitation, version 2.8 (MSWEP v2.8). The two temperature products evaluated in this study are ERA5 and Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA v2). Evaluations of these satellite/reanalysis rainfall and temperature products were undertaken against observed data (1995–2014) in temperate, sub-tropical and tropical agro-ecological zones (AEZs) across multiple temporal scales ranging from the daily to annual. For assessing the performances of satellite/reanalysis rainfall and temperature products, a point-pixel evaluation approach was undertaken using five continuous evaluation scores such as correlation coefficient (R), mean absolute error (MAE), root mean square error (RMSE), percent bias (PBIAS) and Kling–Gupta efficiency (KGE). Categorical sores such as Probability of Detection (POD), False Alarm Ratio (FAR) and Frequency Bias Index (FBI) were also used for assessing the rainfall products. The findings revealed that MSWEP v2.8 has better performance than CHIRPS v2.0 and TAMSAT v3.1 in temperate and tropical AEZs at the daily, dry season and annual time steps as well as in sub-tropical AEZ in dry season and annual temporal periods, but MSWEP v2.8 displayed comparable performance with TAMSAT v3.1 in the daily time step. CHIRPS v2.0 exhibit superior performance in the monthly time scale in the three AEZs as well as in the wet season in temperate and tropical AEZs, but TAMSAT v3.1 has outperformed than CHIRPS v2.0 in the wet season in sub-tropical AEZ. The finding also indicated that the capability of MSWEP v2.8 to detect the rainy days (79–86%) and frequency of rainy days (0.99–1.79) is better than CHIRPS v2.0 and TAMSAT v3.1, but TAMSAT v3.1 has shown the best performance for identifying the non-rainy days (14–38%) than MSWEP v2.8 and CHIRPS v2.0. With regard to temperature, MERRA v2 outperformed over ERA5 in temperate and tropical AEZs for estimating both maximum and minimum temperatures from the daily to annual time scales, but ERA5 has shown superior performance than MERRA v2 in the sub-tropical AEZ. In view of the finding, we concluded that the best performing rainfall and temperature products for each AEZ can be used for data scarce regions such as the BER. The findings of this study provide important insights about the need to identify best performing rainfall and temperature products for different AEZs to enhance the quality of hydro-climate study outputs in the decision-making process.
17 Xie, H.; Dile, Y. T.; Ringler, C.; Srinivasan, R.; Worqlul, A. W.. 2023. Toward a better understanding of the environmental impacts of expanding farmer-led irrigation in Sub-Saharan Africa: an exploratory assessment of irrigation-induced risk of nutrient water pollution in Ethiopia. Environmental Research Communications, 5(6):065001. [doi: https://doi.org/10.1088/2515-7620/acd6db]
Farmer-led irrigation ; Environmental impact ; Water pollution ; Fertilizers ; Crop production ; Agricultural production ; Rain ; Cropping patterns ; Land management / Africa South of Sahara / Ethiopia / Bahir Dar Zuria / Dangla / Adami Tulu / Lemo
(Location: IWMI HQ Call no: e-copy only Record No: H052003)
https://iopscience.iop.org/article/10.1088/2515-7620/acd6db/pdf
https://vlibrary.iwmi.org/pdf/H052003.pdf
https://vlibrary.iwmi.org/pdf/H052003.pdf
(2.03 MB) (2.03 MB)
Irrigation, and especially farmer-led irrigation, is considered to be a promising option for enhancing agricultural productivity in Sub-Saharan Africa. However, there is a lack of thorough understanding of the impacts of irrigation development on environment. Past discussions are mainly limited to the water depletion and hydrological regime change effect of irrigation. This paper presents a study to narrow the knowledge gap by assessing nutrient water pollution risk induced by the expansion of farmer-led irrigation in Ethiopia. Using household survey data collected from four woredas in Ethiopia where irrigated crop production currently concentrates, we first evaluate the impact of irrigation on cropping intensity and annual consumption level of fertilizers and then use the findings of the household survey data analysis to support conceptualization of a modeling framework for assessing agricultural nutrient water pollution risk from farmer-led irrigation development in Ethiopia at national scale. We project that overall farmer-led irrigation development in Ethiopia will lead to a gentle increase in national total of agricultural nutrient loadings. This result helps justify the endeavor of promoting farmer-led irrigation in Ethiopia. On the other hand, the projected nutrient flow and nutrient loading growth rate related to the farmer-led irrigation expansion are highly heterogeneous spatially, and risk of local water quality deterioration exists. There is still need to make investment to ensure the environmental sustainability of farmer-led irrigation development.
18 Aniley, E.; Gashaw, T.; Abraham, T.; Demessie, S. F.; Bayabil, H. K.; Worqlul, A. W.; van Oel, P. R.; Dile, Y. T.; Chukalla, A. D.; Haileslassie, Amare; Wubaye, G. B. 2023. Evaluating the performances of gridded satellite/reanalysis products in representing the rainfall climatology of Ethiopia. Geocarto International, 38(1):2278329. [doi: https://doi.org/10.1080/10106049.2023.2278329]
Rainfall ; Datasets ; Weather data ; Performance assessment ; Climatology ; Satellite observation ; Agroecological zones ; Precipitation / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052402)
https://www.tandfonline.com/doi/epdf/10.1080/10106049.2023.2278329?needAccess=true
https://vlibrary.iwmi.org/pdf/H052402.pdf
https://vlibrary.iwmi.org/pdf/H052402.pdf
(3.33 MB) (3.33 MB)
This study evaluated performances of the Climate Hazard Group Infrared Precipitation with stations version 2.0 (CHIRPS v2.0) and Multi-Source Weighted-Ensemble Precipitation version 2.8 (MSWEP v2.8) products against observed data. Rainfall climatology was simulated for different agro-ecological zones (AEZs) of Ethiopia during 1991–2020 at different temporal scales. Performance evaluations were made using continuous and statistical performance measures as well as Probability Density Function (PDF). CHIRPS v2.0 for estimating monthly, seasonal, and annual rainfall totals, and MSWEP v2.8 for daily rainfall have shown better performance over all AEZs. The two products display comparable performance for detecting daily rainfall occurrences over alpine AEZ, but MSWEP v2.8 is superior in the rest four AEZs. CHIRPS v2.0 outperforms MSWEP v2.8 for detecting most of the daily rainfall intensity classes over all AEZs. The findings will play a noteworthy role to improve the quality of hydro-climate studies in Ethiopia.
19 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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