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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.
Abeyou W. Worqlul; Yihun T. Dile; Petra Schmitter; Melkamu Bezabih; Aberra Adie; Jean-Claude Bizimana; R. Srinivasan; Nicole Lefore; Neville Clarke. Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia. Agricultural Water Management 2021, 254, 106973 .
AMA StyleAbeyou W. Worqlul, Yihun T. Dile, Petra Schmitter, Melkamu Bezabih, Aberra Adie, Jean-Claude Bizimana, R. Srinivasan, Nicole Lefore, Neville Clarke. Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia. Agricultural Water Management. 2021; 254 ():106973.
Chicago/Turabian StyleAbeyou W. Worqlul; Yihun T. Dile; Petra Schmitter; Melkamu Bezabih; Aberra Adie; Jean-Claude Bizimana; R. Srinivasan; Nicole Lefore; Neville Clarke. 2021. "Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia." Agricultural Water Management 254, no. : 106973.
Drought is one of the least understood and complex natural hazards often characterized by a significant decrease in water availability for a prolonged period. It can be manifested in one or more forms as meteorological, agricultural, hydrological, and/or socio-economic drought. The overarching objective of this study is to demonstrate and characterize the different forms of droughts and to assess the multidimensional nature of drought in the Abbay/ Upper Blue Nile River (UBN) basin and its national and regional scale implications. In this study, multiple drought indices derived from in situ and earth observation-based hydro-climatic variables were used. The meteorological drought was characterized using the Standardized Precipitation Index (SPI) computed from the earth observation-based gridded CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) rainfall data. Agricultural and hydrological droughts were characterized by using the Soil Moisture Deficit Index (SMDI) and Standardized Runoff-discharge Index (SRI), respectively. The monthly time series of SMDI was derived from model-based gridded soil moisture and SRI from observed streamflow data from 1982 to 2019. The preliminary result illustrates the good performance of the drought indices in capturing the historic severe drought events (e.g., 1984 and 2002) and the spatial extents across the basin. The results further indicated that all forms of droughts (i.e., meteorological, agricultural, and hydrological) occurred concurrently in Abbay/Upper Blue Nile basin with a Pearson correlation coefficient ranges from 0.5 to 0.85 both Kiremt and annual aggregate periods. The concurrent nature of drought is leading to a multi-dimensional socio-economic crisis as indicated by rainfall, and soil moisture deficits, and drying of small streams. Multi-dimensional drought mitigation necessitates regional cooperation and watershed management to protect both the common water sources of the Abbay/Upper Blue Nile basin and the socio-economic activities of the society in the basin. This study also underlines the need for multi-scale drought monitoring and management practices in the basin.
Yared Bayissa; Semu Moges; Assefa Melesse; Tsegaye Tadesse; Anteneh Abiy; Abeyou Worqlul. Multi-Dimensional Drought Assessment in Abbay/Upper Blue Nile Basin: The Importance of Shared Management and Regional Coordination Efforts for Mitigation. Remote Sensing 2021, 13, 1835 .
AMA StyleYared Bayissa, Semu Moges, Assefa Melesse, Tsegaye Tadesse, Anteneh Abiy, Abeyou Worqlul. Multi-Dimensional Drought Assessment in Abbay/Upper Blue Nile Basin: The Importance of Shared Management and Regional Coordination Efforts for Mitigation. Remote Sensing. 2021; 13 (9):1835.
Chicago/Turabian StyleYared Bayissa; Semu Moges; Assefa Melesse; Tsegaye Tadesse; Anteneh Abiy; Abeyou Worqlul. 2021. "Multi-Dimensional Drought Assessment in Abbay/Upper Blue Nile Basin: The Importance of Shared Management and Regional Coordination Efforts for Mitigation." Remote Sensing 13, no. 9: 1835.
Ethiopia has the largest livestock population in Africa with 35 million tropical livestock units. The livestock system relies on natural open grazing which is affected by frequent droughts. However, little research exists that studies the suitability of the biophysical environment for fodder production and the risks due to climate change. The main objectives of the study are to evaluate the potential effects of climate change on land suitability for alfalfa production in Ethiopia and to assess the extent of irrigation requirements for alfalfa growing under the adverse climate change projections. The impact of climate change on land suitability for alfalfa was evaluated using projected changes in rainfall and temperature based on three global circulation models (CCSM4, HadGEM2-AO, and MIROC5). A multi-criteria evaluation in GIS that uses biophysical, climatic and topography factors was applied to identify the suitable land. The highly suitable area under current climate scenarios covered ~472,000 km2, while moderately suitable and marginally suitable covered ~397,000 km2 and ~16,200 km2, respectively. The projected climate alters the suitable land for fodder production across Ethiopia. Expansion of suitable land occurred in the highlands where climate scenarios predict an increase in temperature and precipitation. Dryland regions showed a rainfall deficit for the three model projections. The research provides guidelines for growing alfalfa in Ethiopia considering ecological and climatic variability.
Sintayehu Alemayehu; Essayas Ayana; Yihun Dile; Teferi Demissie; Yohannes Yimam; Evan Girvetz; Ermias Aynekulu; Dawit Solomon; Abeyou Worqlul. Evaluating Land Suitability and Potential Climate Change Impacts on Alfalfa (Medicago sativa) Production in Ethiopia. Atmosphere 2020, 11, 1124 .
AMA StyleSintayehu Alemayehu, Essayas Ayana, Yihun Dile, Teferi Demissie, Yohannes Yimam, Evan Girvetz, Ermias Aynekulu, Dawit Solomon, Abeyou Worqlul. Evaluating Land Suitability and Potential Climate Change Impacts on Alfalfa (Medicago sativa) Production in Ethiopia. Atmosphere. 2020; 11 (10):1124.
Chicago/Turabian StyleSintayehu Alemayehu; Essayas Ayana; Yihun Dile; Teferi Demissie; Yohannes Yimam; Evan Girvetz; Ermias Aynekulu; Dawit Solomon; Abeyou Worqlul. 2020. "Evaluating Land Suitability and Potential Climate Change Impacts on Alfalfa (Medicago sativa) Production in Ethiopia." Atmosphere 11, no. 10: 1124.
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.
Muluken L. Alemu; Abeyou W. Worqlul; Fasikaw A. Zimale; Seifu A. Tilahun; Tammo S. Steenhuis. Water Balance for a Tropical Lake in the Volcanic Highlands: Lake Tana, Ethiopia. Water 2020, 12, 2737 .
AMA StyleMuluken L. Alemu, Abeyou W. Worqlul, Fasikaw A. Zimale, Seifu A. Tilahun, Tammo S. Steenhuis. Water Balance for a Tropical Lake in the Volcanic Highlands: Lake Tana, Ethiopia. Water. 2020; 12 (10):2737.
Chicago/Turabian StyleMuluken L. Alemu; Abeyou W. Worqlul; Fasikaw A. Zimale; Seifu A. Tilahun; Tammo S. Steenhuis. 2020. "Water Balance for a Tropical Lake in the Volcanic Highlands: Lake Tana, Ethiopia." Water 12, no. 10: 2737.
The largest freshwater lake in Ethiopia, Lake Tana, has faced ecological disaster due to water hyacinth (Eichhornia crassipes) infestation. The water hyacinth is a threat not only to the ecology but also to the socioeconomic development of the region and cultural value of the lake, which is registered as a UNESCO reserve. This study aims to map the spatiotemporal dynamics of the water hyacinth using high-resolution PlanetScope satellite images and assesses the major environmental variables that relate to the weed spatial coverage dynamics for the period August 2017 to July 2018. The plausible environmental factors studied affecting the weed dynamics include lake level, water and air temperature, and turbidity. Water temperature and turbidity were estimated from the moderate resolution imaging spectroradiometer (MODIS) satellite image and the water level was estimated using Jason-1 altimetry data while the air temperature was obtained from the nearby meteorological station at Bahir Dar station. The results indicated that water hyacinth coverage was increasing at a rate of 14 ha/day from August to November of 2017. On the other hand, the coverage reduced at a rate of 6 ha/day from December 2017 to June 2018. However, the length of shoreline infestation increased significantly from 4.3 km in August 2017 to 23.4 km in April 2018. Lake level and night-time water temperatures were strongly correlated with water hyacinth spatial coverage (p < 0.05). A drop in the lake water level resulted in a considerable reduction of the infested area, which is also related to decreasing nutrient levels in the water. The water hyacinth expansion dynamics could be altered by treating the nutrient-rich runoff with best management practices along the wetland and in the lake watershed landscape.
Abeyou W. Worqlul; Essayas K. Ayana; Yihun T. Dile; Mamaru A. Moges; Minychl G. Gitaw; Getachew Tegegne; Solomon Kibret. Spatiotemporal Dynamics and Environmental Controlling Factors of the Lake Tana Water Hyacinth in Ethiopia. Remote Sensing 2020, 12, 2706 .
AMA StyleAbeyou W. Worqlul, Essayas K. Ayana, Yihun T. Dile, Mamaru A. Moges, Minychl G. Gitaw, Getachew Tegegne, Solomon Kibret. Spatiotemporal Dynamics and Environmental Controlling Factors of the Lake Tana Water Hyacinth in Ethiopia. Remote Sensing. 2020; 12 (17):2706.
Chicago/Turabian StyleAbeyou W. Worqlul; Essayas K. Ayana; Yihun T. Dile; Mamaru A. Moges; Minychl G. Gitaw; Getachew Tegegne; Solomon Kibret. 2020. "Spatiotemporal Dynamics and Environmental Controlling Factors of the Lake Tana Water Hyacinth in Ethiopia." Remote Sensing 12, no. 17: 2706.
The frequency and intensity of flood quantiles and its attendant damage in agricultural establishments have generated a lot of issues in Ethiopia. Moreover, precise estimates of flood quantiles are needed for efficient design of hydraulic structures; however, quantification of these quantiles in data-scarce regions has been a continuing challenge in hydrologic design. Flood frequency analysis is thus essential to reduce possible flood damage by investigating the most suitable flood prediction model. The annual maximum discharges from six representative stations in the Upper Blue Nile River Basin were fitted to the commonly used nine statistical distributions. This study also assessed the performance evolution of the probability distributions with varying spatial scales, such that three different spatial scales of small-, medium-, and large-scale basins in the Blue Nile River Basin were considered. The performances of the candidate probability distributions were assessed using three goodness-of-fit test statistics, root mean square error, and graphical interpretation approaches to investigate the robust probability distribution for flood frequency analysis over different basin spatial scales. Based on the overall analyses, the generalized extreme value distribution was proven to be a robust model for flood frequency analysis in the study region. The generalized extreme value distribution significantly improved the performance of the flood prediction over different spatial scales. The generalized extreme value flood prediction performance improvement measured in root mean square error varied between 5.84 and 67.91% over other commonly used probability distribution models. Thus, the flood frequency analysis using the generalized extreme value distribution could be essential for the efficient planning and design of hydraulic structures in the Blue Nile River Basin. Furthermore, this study suggests that, in the future, significant efforts should be put to conduct similar flood frequency analyses over the other major river basins of Ethiopia.
Getachew Tegegne; Assefa Melesse; Dereje Asfaw; Abeyou Worqlul. Flood Frequency Analyses over Different Basin Scales in the Blue Nile River Basin, Ethiopia. Hydrology 2020, 7, 44 .
AMA StyleGetachew Tegegne, Assefa Melesse, Dereje Asfaw, Abeyou Worqlul. Flood Frequency Analyses over Different Basin Scales in the Blue Nile River Basin, Ethiopia. Hydrology. 2020; 7 (3):44.
Chicago/Turabian StyleGetachew Tegegne; Assefa Melesse; Dereje Asfaw; Abeyou Worqlul. 2020. "Flood Frequency Analyses over Different Basin Scales in the Blue Nile River Basin, Ethiopia." Hydrology 7, no. 3: 44.
Water hyacinth originated from the Amazon Basin and has expanded to other parts of the world since the 1800s. In Ethiopia, the weed is affecting the socio-economic activities of the people whose livelihood is directly or indirectly dependent on Lake Tana. Still, the area covered by water hyacinth and the impact of water level fluctuation on the expansion of water hyacinth has not been known clearly. Therefore, the main objective of this study was to determine the spatiotemporal distribution of water hyacinth and relation with lake-level fluctuation. The area covered by water hyacinth was determined using monthly Sentinel-2 images, which were collected from November 2015 to December 2019. The impact of water level fluctuation on the expansion of water hyacinth was evaluated using hourly water level data converted to a monthly average to correlate with the area covered by the water hyacinth. In addition, MOD13Q1.006 data was used to evaluate the trend of the Normalized Difference Vegetation Index (NDVI) and its linkage with the weed. The maximum areas covered by water hyacinth were 278.3, 613.6, 1108.7, 2036.5, and 2504.5 ha in Feb 2015, October 2016, September 2017, December 2018, and in December 2019, respectively. Its areal coverage was declining from the northern corridors and increasing in eastern shores of the lake. The lake-level fluctuation was observed in the range of 1.5 to 3.98 m in this study. The annual mean maximum spatial values of the NDVI were in the range of 0.27 and 0.47. The area covered by water hyacinth was increasing significantly (P < 0.05) and positively correlated with the seasonal lake-level fluctuation. High water level enabled the expansion of the weed by extending its suitable habitat of shallow water to the flood plain. Based on the results of this study, lake-level fluctuations can have an adverse impact on the expansion of the weed.
Minychl G. Dersseh; Seifu A. Tilahun; Abeyou W. Worqlul; Mamaru A. Moges; Wubneh B. Abebe; Demesew A. Mhiret; Assefa M. Melesse. Spatial and Temporal Dynamics of Water Hyacinth and Its Linkage with Lake-Level Fluctuation: Lake Tana, a Sub-Humid Region of the Ethiopian Highlands. Water 2020, 12, 1435 .
AMA StyleMinychl G. Dersseh, Seifu A. Tilahun, Abeyou W. Worqlul, Mamaru A. Moges, Wubneh B. Abebe, Demesew A. Mhiret, Assefa M. Melesse. Spatial and Temporal Dynamics of Water Hyacinth and Its Linkage with Lake-Level Fluctuation: Lake Tana, a Sub-Humid Region of the Ethiopian Highlands. Water. 2020; 12 (5):1435.
Chicago/Turabian StyleMinychl G. Dersseh; Seifu A. Tilahun; Abeyou W. Worqlul; Mamaru A. Moges; Wubneh B. Abebe; Demesew A. Mhiret; Assefa M. Melesse. 2020. "Spatial and Temporal Dynamics of Water Hyacinth and Its Linkage with Lake-Level Fluctuation: Lake Tana, a Sub-Humid Region of the Ethiopian Highlands." Water 12, no. 5: 1435.
Comprehensive spatially referenced soil data are a crucial input in predicting biophysical and hydrological landscape processes. In most developing countries, these detailed soil data are not yet available. The objective of this study was, therefore, to evaluate the detail needed in soil resource inventories to predict the hydrologic response of watersheds. Using three distinctively different digital soil inventories, the widely used and tested soil and water assessment tool (SWAT) was selected to predict the discharge in two watersheds in the headwaters of the Blue Nile: the 1316 km2 Rib watershed and the nested 3.59 km2 Gomit watershed. The soil digital soil inventories employed were in increasing specificity: the global Food and Agricultural Organization (FAO), the Africa Soil Information Service (AfSIS) and the Amhara Design and Supervision Works Enterprise (ADSWE). Hydrologic simulations before model calibration were poor for all three soil inventories used as input. After model calibration, the streamflow predictions improved with monthly Nash–Sutcliffe efficiencies greater than 0.68. Predictions were statistically similar for the three soil databases justifying the use of the global FAO soil map in data-scarce regions for watershed discharge predictions.
Anwar A. Adem; Yihun T. Dile; Abeyou W. Worqlul; Essayas K. Ayana; Seifu A. Tilahun; Tammo S. Steenhuis. Assessing Digital Soil Inventories for Predicting Streamflow in the Headwaters of the Blue Nile. Hydrology 2020, 7, 8 .
AMA StyleAnwar A. Adem, Yihun T. Dile, Abeyou W. Worqlul, Essayas K. Ayana, Seifu A. Tilahun, Tammo S. Steenhuis. Assessing Digital Soil Inventories for Predicting Streamflow in the Headwaters of the Blue Nile. Hydrology. 2020; 7 (1):8.
Chicago/Turabian StyleAnwar A. Adem; Yihun T. Dile; Abeyou W. Worqlul; Essayas K. Ayana; Seifu A. Tilahun; Tammo S. Steenhuis. 2020. "Assessing Digital Soil Inventories for Predicting Streamflow in the Headwaters of the Blue Nile." Hydrology 7, no. 1: 8.
The severity and frequency of climate extremes will change in the future owing to global warming. This can severely impact the natural environment. Therefore, it is common practice to project climate extremes with a global climate model (GCM) in order to quantify and manage the associated risks. Several studies have demonstrated that a multi-model ensemble approach increases the reliability of predictions by exploiting the strengths and discounting the weaknesses of each climate simulator. However, the available multi-model averaging approaches exhibit significant drawbacks as they are not capable of extracting different climate extreme characteristics from the climate models. This study proposes a new approach that combines multiple models for projecting climate extremes by accounting for different extreme indices in the climate model performance weighting scheme. The capability of this method was evaluated with respect to reliability ensemble averaging (REA) and Taylor diagram-based GCM skill approaches for reproducing wet and dry precipitation events. The proposed multi-model averaging approach outperformed the available approaches in reducing the root mean square error (RMSE) by 5% and 54% in the wet and dry precipitation conditions, respectively. Therefore, it can be concluded that incorporating the different precipitation extremes in a multi-model combination approach could enhance the assessment of climate change impacts on the climate extremes. The climate change impacts on the extreme events, based on the proposed multi-model ensembles, is thus assessed using the standardized precipitation indexes of 3 month, 6 month, and 12 month durations. In general, the results exhibited that the frequency of wet events increases, whereas that of drought events decreases.
Getachew Tegegne; Assefa M. Melesse; Abeyou W. Worqlul. Development of multi-model ensemble approach for enhanced assessment of impacts of climate change on climate extremes. Science of The Total Environment 2019, 704, 135357 .
AMA StyleGetachew Tegegne, Assefa M. Melesse, Abeyou W. Worqlul. Development of multi-model ensemble approach for enhanced assessment of impacts of climate change on climate extremes. Science of The Total Environment. 2019; 704 ():135357.
Chicago/Turabian StyleGetachew Tegegne; Assefa M. Melesse; Abeyou W. Worqlul. 2019. "Development of multi-model ensemble approach for enhanced assessment of impacts of climate change on climate extremes." Science of The Total Environment 704, no. : 135357.
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 field-scale 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.
Abeyou W. Worqlul; Yihun T. Dile; Petra Schmitter; Jaehak Jeong; Manyowa N. Meki; Thomas J. Gerik; Raghavan Srinivasan; Nicole Lefore; Neville Clarke. Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia. Agricultural Water Management 2019, 226, 105767 .
AMA StyleAbeyou W. Worqlul, Yihun T. Dile, Petra Schmitter, Jaehak Jeong, Manyowa N. Meki, Thomas J. Gerik, Raghavan Srinivasan, Nicole Lefore, Neville Clarke. Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia. Agricultural Water Management. 2019; 226 ():105767.
Chicago/Turabian StyleAbeyou W. Worqlul; Yihun T. Dile; Petra Schmitter; Jaehak Jeong; Manyowa N. Meki; Thomas J. Gerik; Raghavan Srinivasan; Nicole Lefore; Neville Clarke. 2019. "Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia." Agricultural Water Management 226, no. : 105767.
The conservation agriculture production system (CAPS) approach with drip irrigation has proven to have the potential to improve water management and food production in Ethiopia. A method of scaling-up crop yield under CAPS with drip irrigation is developed by integrating a biophysical model: APEX (agricultural policy environmental eXtender), and a Geographic Information System (GIS)-based multi-criteria evaluation (MCE) technique. Topography, land use, proximity to road networks, and population density were considered in identifying potentially irrigable land. Weather and soil texture data were used to delineate unique climate zones with similar soil properties for crop yield simulation using well-calibrated crop model parameters. Crops water demand for the cropping periods was used to determine groundwater potential for irrigation. The calibrated APEX crop model was then used to predict crop yield across the different climatic and soil zones. The MCE technique identified about 18.7 Mha of land (16.7% of the total landmass) as irrigable land in Ethiopia. Oromia has the highest irrigable land in the nation (35.4% of the irrigable land) when compared to other regional states. Groundwater could supply a significant amount of the irrigable land for dry season production under CAPS with drip irrigation for the various vegetables tested at the experimental sites with about 2.3 Mha, 3.5 Mha, 1.6 Mha, and 1.4 Mha of the irrigable land available to produce garlic, onion, cabbage, and tomato, respectively. When comparing regional states, Oromia had the highest groundwater potential (40.9% of total potential) followed by Amhara (20%) and Southern Nations, Nationalities, and Peoples (16%). CAPS with drip irrigation significantly increased groundwater potential for irrigation when compared to CTPS (conventional tillage production system) with traditional irrigation practice (i.e., 0.6 Mha under CTPS versus 2.2 Mha under CAPS on average). Similarly, CAPS with drip irrigation depicted significant improvement in crop productivity when compared to CTPS. APEX simulation of the average fresh vegetable yield on the irrigable land under CAPS with drip irrigation ranged from 1.8–2.8 t/ha, 1.4–2.2 t/ha, 5.5–15.7 t/ha, and 8.3–12.9 t/ha for garlic, onion, tomato, and cabbage, respectively. CAPS with drip irrigation technology could improve groundwater potential for irrigation up to five folds and intensify crop productivity by up to three to four folds across the nation.
Tewodros Assefa; Manoj Jha; Abeyou W. Worqlul; Manuel Reyes; Seifu Tilahun. Scaling-Up Conservation Agriculture Production System with Drip Irrigation by Integrating MCE Technique and the APEX Model. Water 2019, 11, 2007 .
AMA StyleTewodros Assefa, Manoj Jha, Abeyou W. Worqlul, Manuel Reyes, Seifu Tilahun. Scaling-Up Conservation Agriculture Production System with Drip Irrigation by Integrating MCE Technique and the APEX Model. Water. 2019; 11 (10):2007.
Chicago/Turabian StyleTewodros Assefa; Manoj Jha; Abeyou W. Worqlul; Manuel Reyes; Seifu Tilahun. 2019. "Scaling-Up Conservation Agriculture Production System with Drip Irrigation by Integrating MCE Technique and the APEX Model." Water 11, no. 10: 2007.
Water hyacinth is a well-known invasive weed in lakes across the world and harms the aquatic environment. Since 2011, the weed has invaded Lake Tana substantially posing a challenge to the ecosystem services of the lake. The major factors which affect the growth of the weed are phosphorus, nitrogen, temperature, pH, salinity, and lake depth. Understanding and investigating the hotspot areas is vital to predict the areas for proper planning of interventions. The main objective of this study is therefore to predict the hotspot areas of the water hyacinth over the surface of the lake using the geographical information system (GIS)-based multi-criteria evaluation (MCE) technique. The main parameters used in the multi-criteria analysis were total phosphorus (>0.08 mg L−1), total nitrogen (>1.1 mg L−1), temperature (
Minychl G. Dersseh; Aron A. Kibret; Seifu A. Tilahun; Abeyou W. Worqlul; Mamaru A. Moges; Dessalegn C. Dagnew; Wubneh B. Abebe; Assefa M. Melesse. Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique. Water 2019, 11, 1921 .
AMA StyleMinychl G. Dersseh, Aron A. Kibret, Seifu A. Tilahun, Abeyou W. Worqlul, Mamaru A. Moges, Dessalegn C. Dagnew, Wubneh B. Abebe, Assefa M. Melesse. Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique. Water. 2019; 11 (9):1921.
Chicago/Turabian StyleMinychl G. Dersseh; Aron A. Kibret; Seifu A. Tilahun; Abeyou W. Worqlul; Mamaru A. Moges; Dessalegn C. Dagnew; Wubneh B. Abebe; Assefa M. Melesse. 2019. "Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique." Water 11, no. 9: 1921.
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 (α = 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.
Tewodros Assefa; Manoj Jha; Manuel Reyes; Seifu Tilahun; Abeyou W. Worqlul. Experimental Evaluation of Conservation Agriculture with Drip Irrigation for Water Productivity in Sub-Saharan Africa. Water 2019, 11, 530 .
AMA StyleTewodros Assefa, Manoj Jha, Manuel Reyes, Seifu Tilahun, Abeyou W. Worqlul. Experimental Evaluation of Conservation Agriculture with Drip Irrigation for Water Productivity in Sub-Saharan Africa. Water. 2019; 11 (3):530.
Chicago/Turabian StyleTewodros Assefa; Manoj Jha; Manuel Reyes; Seifu Tilahun; Abeyou W. Worqlul. 2019. "Experimental Evaluation of Conservation Agriculture with Drip Irrigation for Water Productivity in Sub-Saharan Africa." Water 11, no. 3: 530.
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.
Abeyou Wale Worqlul; Yihun T. Dile; Jaehak Jeong; Zenebe Adimassu; Nicole Lefore; Thomas Gerik; Raghavan Srinivasan; Neville Clarke. Effect of climate change on land suitability for surface irrigation and irrigation potential of the shallow groundwater in Ghana. Computers and Electronics in Agriculture 2018, 157, 110 -125.
AMA StyleAbeyou Wale Worqlul, Yihun T. Dile, Jaehak Jeong, Zenebe Adimassu, Nicole Lefore, Thomas Gerik, Raghavan Srinivasan, Neville Clarke. Effect of climate change on land suitability for surface irrigation and irrigation potential of the shallow groundwater in Ghana. Computers and Electronics in Agriculture. 2018; 157 ():110-125.
Chicago/Turabian StyleAbeyou Wale Worqlul; Yihun T. Dile; Jaehak Jeong; Zenebe Adimassu; Nicole Lefore; Thomas Gerik; Raghavan Srinivasan; Neville Clarke. 2018. "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, no. : 110-125.
The agricultural system in Sub-Saharan Africa (SSA) is dominated by traditional farming practices with poor soil and water management, which contributes to soil degradation and low crop productivity. This study integrated field experiments and a field-scale biophysical model (Agricultural Policy Environmental Extender, APEX) to investigate the impacts of conservation agriculture (CA) with a drip irrigation system on the hydrology and water management as compared to the conventional tillage (CT) practice. Field data were collected from four study sites; Dangishita and Robit (Ethiopia), Yemu (Ghana), and Mkindo (Tanzania) to validate APEX for hydrology and crop yield simulation. Each study site consisted of 100 m2 plots divided equally between CA and CT practices and both had a drip irrigation setup. Cropping pattern, management practices, and irrigation scheduling were monitored for each experimental plot. Significant water savings (α = 0.05) were observed under CA practice; evapotranspiration and runoff were reduced by up to 49% and 62%, respectively, whereas percolation increased up to three-fold. Consequently, irrigation water need was reduced in CA plots by about 14–35% for various crops. CA coupled with drip irrigation was found to be an efficient water saving technology and has substantial potential to sustain and intensify crop production in the region.
Tewodros Assefa; Manoj Jha; Manuel Reyes; Abeyou W. Worqlul. Modeling the Impacts of Conservation Agriculture with a Drip Irrigation System on the Hydrology and Water Management in Sub-Saharan Africa. Sustainability 2018, 10, 4763 .
AMA StyleTewodros Assefa, Manoj Jha, Manuel Reyes, Abeyou W. Worqlul. Modeling the Impacts of Conservation Agriculture with a Drip Irrigation System on the Hydrology and Water Management in Sub-Saharan Africa. Sustainability. 2018; 10 (12):4763.
Chicago/Turabian StyleTewodros Assefa; Manoj Jha; Manuel Reyes; Abeyou W. Worqlul. 2018. "Modeling the Impacts of Conservation Agriculture with a Drip Irrigation System on the Hydrology and Water Management in Sub-Saharan Africa." Sustainability 10, no. 12: 4763.
Note: In lieu of an abstract, this is an excerpt from the first page.Excerpt The authors wish to make the following correction to their paper [1]: The second author’s name should be changed from “Yihun Dile Taddele” to “Yihun Taddele Dile”
Abeyou Wale Worqlul; Yihun Taddele Dile; Essayas Kaba Ayana; Jaehak Jeong; Anwar Assefa Adem; Thomas Gerik. Erratum: Worqlul, A.W.; et al. Impact of Climate Change on Streamflow Hydrology in Headwater Catchments of the Upper Blue Nile Basin, Ethiopia. Water 2018, 10, 120. Water 2018, 10, 761 .
AMA StyleAbeyou Wale Worqlul, Yihun Taddele Dile, Essayas Kaba Ayana, Jaehak Jeong, Anwar Assefa Adem, Thomas Gerik. Erratum: Worqlul, A.W.; et al. Impact of Climate Change on Streamflow Hydrology in Headwater Catchments of the Upper Blue Nile Basin, Ethiopia. Water 2018, 10, 120. Water. 2018; 10 (6):761.
Chicago/Turabian StyleAbeyou Wale Worqlul; Yihun Taddele Dile; Essayas Kaba Ayana; Jaehak Jeong; Anwar Assefa Adem; Thomas Gerik. 2018. "Erratum: Worqlul, A.W.; et al. Impact of Climate Change on Streamflow Hydrology in Headwater Catchments of the Upper Blue Nile Basin, Ethiopia. Water 2018, 10, 120." Water 10, no. 6: 761.
This paper studied the impacts of small-scale irrigation (SSI) interventions on environmental sustainability, agricultural production, and socio-economics using an Integrated Decision Support System (IDSS). The IDSS is comprised of a suite of models, namely the Soil and Water Assessment Tool (SWAT), Agricultural Policy/Environmental eXtender (APEX), and Farm Income and Nutrition Simulator (FARMSIM). The IDSS was applied in Dimbasinia watershed in northern Ghana using irrigation water from shallow groundwater. The watershed has a modest amount of shallow groundwater resources. However, the average annual irrigation water requirement exceeded the average annual shallow groundwater recharge. It was found that the current crop yield in Dimbasinia watershed was only ~40% of the potential crop production. This is mainly related to climate variability, low soil fertility, and land-management practices. For example, application of 50 kg/ha urea and 50 kg/ha DAP doubled maize and sorghum yield from the current farmers’ practices. Better income was obtained when irrigated vegetables/fodder were cultivated in rotation with sorghum as compared to in rotation with maize. Investment in solar pumps paid better dividends and also supplied clean energy. The socio-economic analysis indicated that having irrigated dry season vegetables will improve household nutrition. Since shallow groundwater recharge alone may not provide sufficient water for irrigation in a sustainable manner, surface water may be stored using water-harvesting structures to supplement the groundwater for irrigation. Integrated use of the water resources will also reduce depletion of the shallow groundwater aquifer. We conclude that IDSS is a promising tool to study gaps and constraints as well as upscaling of SSI.
Abeyou W. Worqlul; Yihun T. Dile; Jean-Claude Bizimana; Jaehak Jeong; Thomas J. Gerik; Raghavan Srinivasan; James W. Richardson; Neville Clarke. Multi-Dimensional Evaluation of Simulated Small-Scale Irrigation Intervention: A Case Study in Dimbasinia Watershed, Ghana. Sustainability 2018, 10, 1531 .
AMA StyleAbeyou W. Worqlul, Yihun T. Dile, Jean-Claude Bizimana, Jaehak Jeong, Thomas J. Gerik, Raghavan Srinivasan, James W. Richardson, Neville Clarke. Multi-Dimensional Evaluation of Simulated Small-Scale Irrigation Intervention: A Case Study in Dimbasinia Watershed, Ghana. Sustainability. 2018; 10 (5):1531.
Chicago/Turabian StyleAbeyou W. Worqlul; Yihun T. Dile; Jean-Claude Bizimana; Jaehak Jeong; Thomas J. Gerik; Raghavan Srinivasan; James W. Richardson; Neville Clarke. 2018. "Multi-Dimensional Evaluation of Simulated Small-Scale Irrigation Intervention: A Case Study in Dimbasinia Watershed, Ghana." Sustainability 10, no. 5: 1531.
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.
Yihun Taddele Dile; Sirak Tekleab; Essayas K. Ayana; Solomon G. Gebrehiwot; Abeyou Wale Worqlul; Haimanote K. Bayabil; Yohannes T. Yimam; Seifu A. Tilahun; Prasad Daggupati; Louise Karlberg; Raghavan Srinivasan. Advances in water resources research in the Upper Blue Nile basin and the way forward: A review. Journal of Hydrology 2018, 560, 407 -423.
AMA StyleYihun Taddele Dile, Sirak Tekleab, Essayas K. Ayana, Solomon G. Gebrehiwot, Abeyou Wale Worqlul, Haimanote K. Bayabil, Yohannes T. Yimam, Seifu A. Tilahun, Prasad Daggupati, Louise Karlberg, Raghavan Srinivasan. Advances in water resources research in the Upper Blue Nile basin and the way forward: A review. Journal of Hydrology. 2018; 560 ():407-423.
Chicago/Turabian StyleYihun Taddele Dile; Sirak Tekleab; Essayas K. Ayana; Solomon G. Gebrehiwot; Abeyou Wale Worqlul; Haimanote K. Bayabil; Yohannes T. Yimam; Seifu A. Tilahun; Prasad Daggupati; Louise Karlberg; Raghavan Srinivasan. 2018. "Advances in water resources research in the Upper Blue Nile basin and the way forward: A review." Journal of Hydrology 560, no. : 407-423.
The study was conducted in Lake Tana Basin of Ethiopia to assess potentially irrigable areas for home gardens, water availability, and feasibility of water-lifting technologies. A GIS-based Multi-Criteria Evaluation (MCE) technique was applied to access the potential of surface and groundwater sources for irrigation. The factors affecting irrigation practice were identified and feasibility of water-lifting technologies was evaluated. Pairwise method and expert’s opinion were used to assign weights for each factor. The result showed that about 345,000 ha and 135,000 ha of land were found suitable for irrigation from the surface and groundwater sources, respectively. The rivers could address about 1–1.2% of the irrigable land during dry season without water storage structure whereas groundwater could address about 2.2–2.4% of the irrigable land, both using conventional irrigation techniques. If the seven major dams within the basin were considered, surface water potential would be increased and satisfy about 21% of the irrigable land. If rainwater harvesting techniques were used, about 76% of the basin would be suitable for irrigation. The potential of surface and groundwater was evaluated with respect to water requirements of dominant crops in the region. On the other hand, rope pump and deep well piston hand pump were found with relatively the most (26%) and the least (9%) applicable low-cost water-lifting technologies in the basin.
Tewodros Assefa; Manoj Jha; Manuel Reyes; Raghavan Srinivasan; Abeyou W. Worqlul. Assessment of Suitable Areas for Home Gardens for Irrigation Potential, Water Availability, and Water-Lifting Technologies. Water 2018, 10, 495 .
AMA StyleTewodros Assefa, Manoj Jha, Manuel Reyes, Raghavan Srinivasan, Abeyou W. Worqlul. Assessment of Suitable Areas for Home Gardens for Irrigation Potential, Water Availability, and Water-Lifting Technologies. Water. 2018; 10 (4):495.
Chicago/Turabian StyleTewodros Assefa; Manoj Jha; Manuel Reyes; Raghavan Srinivasan; Abeyou W. Worqlul. 2018. "Assessment of Suitable Areas for Home Gardens for Irrigation Potential, Water Availability, and Water-Lifting Technologies." Water 10, no. 4: 495.
Hydrologic simulations of different models have direct impact on the accuracy of discharge prediction because of the diverse model structure. This study is an attempt to comprehend the uncertainty in discharge prediction of two models in the Ghatshila catchment, Subarnarekha Basin in India. A lumped Probability Distribution Model (PDM) and semi-distributed Soil and Water Assessment Tool (SWAT) were applied to simulate the discharge from 24 years of records (1982–2005), using gridded ground based meteorological variables. The results indicate a marginal outperformance of SWAT model with 0.69 Nash-Sutcliffe (NSE) for predicting discharge as compared to PDM with 0.62 NSE value. Extreme high flows are clearly depicted in the flow duration curve of SWAT model simulations. PDM model performed well in capturing low flows. However, with respect to input datasets and model complexity, SWAT requires both static and dynamic inputs for the parameterization of the model. This work is the comprehensive evaluation of discharge prediction in an Indian scenario using the selected models; ground based gridded rainfall and meteorological dataset. Uncertainty in the model prediction is established by means of Generalized Likelihood Uncertainty Estimation (GLUE) technique in both of the models.
Aradhana Yaduvanshi; Prashant Srivastava; Abeyou W. Worqlul; Anand Kr Sinha. Uncertainty in a Lumped and a Semi-Distributed Model for Discharge Prediction in Ghatshila Catchment. Water 2018, 10, 381 .
AMA StyleAradhana Yaduvanshi, Prashant Srivastava, Abeyou W. Worqlul, Anand Kr Sinha. Uncertainty in a Lumped and a Semi-Distributed Model for Discharge Prediction in Ghatshila Catchment. Water. 2018; 10 (4):381.
Chicago/Turabian StyleAradhana Yaduvanshi; Prashant Srivastava; Abeyou W. Worqlul; Anand Kr Sinha. 2018. "Uncertainty in a Lumped and a Semi-Distributed Model for Discharge Prediction in Ghatshila Catchment." Water 10, no. 4: 381.