37 research outputs found

    Evaluation of regional climate models performance in simulating rainfall climatology of Jemma sub-basin, Upper Blue Nile Basin, Ethiopia

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    This study examines the performance of 10 Regional Climate Model (RCM) outputs which are dynamically downscaled from the fifth phase of Coupled Model Inter-comparison Project (CMIP5) GCMs using different RCMs parameterization approaches. The RCMs are evaluated based on their ability to reproduce the magnitude and pattern of monthly and annual rainfall, characteristics of rainfall events and variability related to Sea Surface Temperature (SST) for the period 1981–2005. The outputs of all RCMs showed wet bias, particularly in the higher elevation areas of the sub-basin. Wet bias of annual rainfall ranges from 9.60% in CCLM4 (HadGEM2-ES) model to 110.9% in RCA4 (EC-EARTH) model. JJAS (June-September) rainfall is also characterized by wet bias ranges from 0.76% in REMO (MPI-ESM-LR) model to 100.7% in RCA4 (HadGEM2-ES) model. GCMs that were dynamically downscaled through REMO (Max Planck Institute) and CCLM4 (Climate Limited-Area Modeling) performed better in capturing the rainfall climatology and distribution of rainfall events. However, GCMs dynamically downscaled using RCA4 (SMHI Rossby Center Regional Atmospheric Model) were characterized by overestimation and there are more extreme rainfall events in the cumulative distribution. Most of the RCMs’ rainfall over the sub-basin showed a teleconnection with Sea Surface Temperature (SST) of CMIP5 GCMs in the Pacific and Indian Oceans, but weak. The ensemble mean of all 10 RCMs simulations was superior in capturing the seasonal pattern of the rainfall and had better correlation with observed annual (Correl = 0.6) and JJAS season rainfall (Correl = 0.5) than any single model (S-RCM). We recommend using GCMs downscaled using REMO and CCLM4 RCMs and stations based statistical bias correction to manage elevation based biases of RCMs in the Upper Blue Nile Basin, specifically in the Jemma sub-basin

    Observed changes in extremes of daily rainfall and temperature in Jemma Sub-Basin, Upper Blue Nile Basin, Ethiopia

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    Climate variability has been a threat to the socio-economic development of Ethiopia. This paper examined the changes in rainfall, minimum, and maximum temperature extremes of Jemma Sub-Basin of the Upper Blue Nile Basin for the period of 1981 to 2014. The nonparametric Mann-Kendall, seasonal Mann-Kendall, and Sen’s slope estimator were used to estimate annual trends. Ten rainfall and 12 temperature indices were used to study changes in rainfall and temperature extremes. The results showed an increasing trend of annual and summer rainfall in more than 78% of the stations and a decreasing trend of spring rainfall in most of the stations. An increase in rainfall extreme events was detected in the majority of the stations. Several rainfall extreme indices showed wetting trends in the sub-basin, whereas limited indices indicated dryness in most of the stations. Annual maximum and minimum temperature and extreme temperature indices showed warming trend in the sub-basin. Presence of extreme rainfall and a warming trend of extreme temperature indices may suggest signs of climate change in the Jemma Sub-Basin. This study, therefore, recommended the need for exploring climate induced risks and implementing appropriate climate change adaptation and mitigation strategies

    Statistical bias correction of regional climate model simulations for climate change projection in the Jemma sub-basin, upper Blue Nile Basin of Ethiopia

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    This study evaluates bias correction methods and develops future climate scenarios using the output of a better bias correctiontechnique at the Jemma sub-basin. The performance of different bias correction techniques was evaluated using several statisticalmetrics. The bias correction methods performance under climate condition different from the current climate was also evaluatedusing the differential split sample testing (DSST) and reveals that the distribution mapping technique is valid under climatecondition different from the current climate. All bias correction methods were effective in adjusting mean monthly and annualRCM simulations of rainfall and temperature to the observed rainfall and temperature values. However, distribution mappingmethod was better in capturing the 90th percentile of observed rainfall and temperature and wet day probability of observedrainfall than other methods. As a result, we use the future (2021–2100) simulation of RCMs which are bias corrected usingdistribution mapping technique. The output of bias-adjusted RCMs unfolds a decline of rainfall, a persistent increase of temperature and an increase of extremes of rainfall and temperature in the future climate under emission scenarios of RepresentativeConcentration Pathways 4.5, 8.5 and 2.6 (RCP4.5, RCP8.5 and RCP2.6). Thus, climate adaptation strategies that can provideoptimal benefits under different climate scenarios should be developed to reduce the impact of future climate change

    "Trends in Extreme Climate Events over Three Agroecological Zones of Southern Ethiopia,"

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    The study aims to assess trends in extremes of surface temperature and precipitation through the application of the World Meteorological Organization's (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI) on datasets representing three agroecological zones in Southern Ethiopia. The indices are applied to daily temperature and precipitation data. Nonparametric Sen's slope estimator and Mann–Kendall's trend tests are used to detect the magnitude and statistical significance of changes in extreme climate, respectively. All agroecological zones (AEZs) have experienced both positive and negative trends of change in temperature extremes. Over three decades, warmest days, warmest nights, and coldest nights have shown significantly increasing trends except in the midland AEZ where warmest days decreased by 0.017°C/year (p<0.05). Temperature extreme's magnitude of change is higher in the highland AEZ and lower in the midland AEZ. The trend in the daily temperature range shows statistically significant decrease across AEZs (p<0.05). A decreasing trend in the cold spell duration indicator was observed in all AEZs, and the magnitude of change is 0.667 days/year in lowland (p<0.001), 2.259 days/year in midland, and 1 day/year in highland (p<0.05). On the contrary, the number of very wet days revealed a positive trend both in the midland and highland AEZs (p<0.05). Overall, it is observed that warm extremes are increasing while cold extremes are decreasing, suggesting considerable changes in the AEZs

    Climate Variability and Farmers' Perception in Southern Ethiopia

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    The study aims to analyze climate variability and farmers' perception in Southern Ethiopia. Gridded annual temperature and precipitation data were obtained from the National Meteorological Agency (NMA) of Ethiopia for the period between 1983 and 2014. Using a multistage sampling technique, 403 farm households were surveyed to substantiate farmers' perceptions about climate variability and change. The study applied a nonparametric Sen's slope estimator and Mann–Kendall's trend tests to detect the magnitude and statistical significance of climate variability and binary logit regression model to find factors influencing farm households' perceptions about climate variability over three agroecological zones (AEZs). The trend analysis reveals that positive trends were observed in the annual maximum temperature, 0.02°C/year (p<0.01) in the lowland and 0.04°C/year (p<0.01) in the highland AEZs. The positive trend in annual minimum temperature was consistent in all AEZs and significant (p<0.01). An upward trend in the annual total rainfall (10 mm/year) (p<0.05) was recorded in the midland AEZ. Over 60% of farmers have perceived increasing temperature and decreasing rainfall in all AEZs. However, farmers' perception about rainfall in the midland AEZ contradicts with meteorological analysis. Results from the binary logit model inform that farmers' climate change perceptions are significantly influenced by their access to climate and market information, agroecology, education, agricultural input, and village market distance. Based on these results, it is recommended to enhance farm households' capacity by providing timely weather and climate information along with institutional actions such as agricultural extension services

    Assessment of the level and factors associated with knowledge, attitude and practice of blood donation among medical and paramedical personnel in ALERT Hospital, Ethiopia

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    Background: Though there was a high blood supply need in response to high communicable disease and increased emergency conditions; the practice of health professionals and non-health professionals on voluntary blood donation is still unexpectedly low in Ethiopia. Health professionals and non-health professionals working in the health sectors are pivotal in taking the lead to reverse the effect of inadequate blood supply system in the country. Therefore, the study aimed to understand the level and contributing factors of Knowledge, Attitude and Practice of voluntary blood donation among health and non-health professionals in ALERT Hospital, Addis Ababa, Ethiopia.Design and Methods:&nbsp;A cross-sectional study design was conducted among health professionals and non-health professionals in ALERT hospital from 5 to 30 June 2018. A total of 394 hospital staffs participated in this study. A well-structured self-administered questionnaire was used to assess the knowledge, attitude, and practice about voluntary blood donation. The statistical analysis was carried out using R.Results: A total of 203 (51.5%) participants were females. Only 142 (36%) of the participants had voluntary blood donation practice. Among these, 60 (42.3%) of them were donated blood more than once. Occupation is the only factor significantly associated with blood donation practice; health professionals had almost two-fold donation practice than non-health professionals with (AOR=1.62; 5%CI: 1.02, 2.57, p=0.042). Occupation has also a strong relationship with knowledge, health professionals had better knowledge than non-professionals with (AOR=2.39; 95% CI: 1.39, 4.12; p=0.002). The result also showed that the educational status of the participants was strongly associated with the blood donors’ attitude (AOR=3.62; 95% CI: 1.1, 11.93, p=0.035). One hundred and two (72.3%) of the blood donors were motivated to donate blood for charity, 133 (94.3%) individuals were felt good after blood donation and lack of request was the major reason 88.6% that causes the respondents not to donate blood frequently.&nbsp;Conclusions: Low blood donation practice of health professionals and non-health professionals was identified from this study. Occupation had significantly associated with blood donation practice. Therefore, targeted interventions aimed at mobilizing hospital staffs and develop accessible blood donation centers are recommended to reverse the effect of inadequate blood supply system in Ethiopia

    Indigenous astronomical knowledge based seasonal weather forecast: evidence from Borana Oromo pastoralists of Southern Ethiopia [version 1; peer review: 2 approved, 1 approved with reservations]

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    Indigenous knowledge is still widely used by communities around the world to overcome social-ecological challenges. Borana Oromo pastoralists of Southern Ethiopia have been searching for future weather phenomena using their indigenous knowledge. This study examines indigenous knowledge-based seasonal weather forecasts through using observable physical and temporal patterns of astronomic objects. Data were generated through using focus group discussion, experimental knowledgeable groups and direct observation in the year 2021. The finding reveals that Borana Oromo pastoralists commonly define physical and temporal outlooks of the Moon that are changed and/ or displayed periodically within a range of varying contexts. The observation of the Moon features have been offering sufficient lapse time in a more than/within ahead of a season/ and is relatively more accurate than the other traditional forecasting objects. The study showed that both temporal and spatial dimensions of the forecasting were actually happened in Ganna (March to May rainfall), Adolessa dry season (June to September) and Hgayya rainfall (October to November) seasons of 2021. This indigenous weather forecasting practices are still regularly used in every livelihood decision making process. However, this indigenous weather knowledge of Borana Oromo pastoralists of Southern Ethiopia is not yet mainstreamed in the formal institutional structures. Curtailments of mobility, severity of drought, weakening of traditional institution, leaving of traditional life style and death of the knowledgeable elders are the major factors that are challenging the potential effects of the indigenous weather forecasting indicators of the features of moon in the study area

    Sustainable Use of Soil and Water Conservation Technologies and Its Determinants: The Case of the Handosha Watershed, Omo-Gibe River Basin, Ethiopia

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    For the past forty years, Ethiopia has been promoting sustainable land management activities to enhance agricultural productivity. This study was intended to identify the factors determining farmers’ adoption and continued use of soil bund measures in the Handosha watershed, Omo-Gibe river basin. A multistage sampling technique was used to select 340 households using the Heckman sample selection model. A total of 235 (69.12%) households adopted soil bunds, but only 89 (37.87%) of them were sustainably practicing soil bunds on their farm plots. Most adopters widely practiced soil bunds (49.42%), followed by stone bund (15.9%), and Fanyajuu (10%). The empirical results of the Heckman sample selection model showed that the farming experience, land tenure security, and perception of profitability of conservation measures were significantly positively affected the adoption of soil bund. Whereas, farm plot size and participation in off farm activities significantly negatively influenced the adoption of soil bund. Sustainable use of soil bund measures were significantly positively influenced by land tenure security, family size, and frequency of extension contact, whereas the distance between farm plots and home, and farm plot size were negatively affected. As a result, a design of agro-ecological-based soil and water conservation (SWC) measures was essential in reducing farmland vulnerability to soil erosion and food insecurity. It has been concluded that conservation practices should not only focus on the implementation and biophysical factors but also consider the socioeconomic interests of the farmers to improve the sustainable use of conservation technologies

    Spatio-temporal Economic Sustainability Convergence in Koga Irrigation and Watershed Project, Amhara Region, Ethiopia

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    The spatio-temporal economic sustainability convergence of twelve irrigation blocks in the Koga irrigation and watershed project was tested in this study. Data on technical efficiency were used to examine the expected growth and speed of convergence in order to reach the production frontier and achieve similar economic sustainability. The study used inefficiency parameterizations, convergence theory, and scenario development as a methodology on a survey questionnaire that includes household demography, operational, and farm-specific data in a trans-log stochastic frontier model. The efficiency parameterization was used to identify the level of economic sustainability, and the convergence theory and scenario development were used to calculate the expected growth rate of efficiency and the speed of convergence in years. The main findings are that a household at the project level requires 9.42 percent growth to achieve optimum efficiency over ten years, and a farmer requires 15.46 years if the minimum reasonable growth rate of 6 percent per year is assumed. The findings that policymakers appear to be increasingly emphasizing efforts to improve the efficiency of less efficient farmers rather than investing in new technologies and inputs to ensure higher levels of economic sustainability highlight the critical role of efficiency improvement. Over a five-year period, the economic sustainability catch-up effect requires a growth differential of 2.11 - 9.45 percent. Household size, frequency of consultation visits, male household heads, the sharecroppers' mentality, and non-farm income are thought to facilitate convergence at the frontier while fostering experience sharing towards a similar level of sustainability. On various grounds, the expected growth rate and speed of convergence were discovered to be reasonable targets in the study area. The calculated expected growth rate was very close to what other studies confirmed. As a result of the findings, local governments should consider convergence at the frontier as a long-term plan and catch up for short-term goals

    Value Chain Analysis of Eucalyptus Wood Products in the Blue Nile Highlands of Northwestern Ethiopia

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    Eucalyptus wood products contribute significantly to the income of smallholder growers in many parts of Ethiopia. This has incentivized smallholders to convert arable lands to Eucalyptus plantation. Given the limited attention and availability of empirical evidence, this study examined the Eucalyptus wood products value chain in terms of the actors engaged, the type and importance of channels, margins analysis and the overall value chain governance in the main Eucalyptus growing areas of the Blue Nile highlands of Northwestern Ethiopia in 2019/2020. Sources of data were randomly selected 388 Eucalyptus grower households and 166 Eucalyptus wood traders, complemented by an interview with key informants, group discussions and direct observations. The results reveal that a total of 2,051,114.75 m3 of Eucalyptus wood was produced in the study area and Eucalyptus plantations are expanding over crop lands at a rate of 102.35 ha a year on average. Many actors involved handle a large volume of wood in eight main channels with a high disparity in the shares of the margins. We found that Eucalyptus is the main source of cash earning, contributing about 45.76% to the total annual income of smallholder growers. Little policy attention, a lack of sectoral integration, missing infrastructure and an absence of modern wood processing factories are among the key challenges impeding the performance of the wood sector value chain. There are however existing opportunities for the development of the wood sector value chain such as favorable growing conditions and the spectacular growing demand for wood products. The study provides valuable insights about the wood sector value chain and actions towards ensuring sustainable value chains and the commercialization of the sector
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