152 research outputs found

    The effect of slope steepness and antecedent moisture content on interrill erosion, runoff and sediment size distribution in the highlands of Ethiopia

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    Soil erosion is a two-phase process consisting of the detachment of individual particles and their transport by the flowing water. This study discusses the results of laboratory experiments in which for three soils, the runoff depth, sediment yield, splash erosion and sediment size were measured. Rainfall intensity, slope and antecedent moisture contents were varied in the experiment. The soil types ranged from clay to sandy clay loam (Alemaya Black soil, Regosols and Cambisols). Rainfall was applied for six sequential 15-min periods with rainfall intensities varying between 55 and 120 mm h<sup>−1</sup>. The three slopes tested were 9, 25, and 45 %. Results show that as slope increased from 9 to 25 %, splash erosion and sediment yield increased. An increase in slope from 25 to 45 % generally decreases in splash erosion. Sediment yield for one soil increased and one soil decreased with slope and for the third soil the trend was different between the two initial moisture contents. Sediment yield was correlated (<i>r</i> = 0.66) with runoff amounts but not with splash erosion. Interrill erosion models that were based on the flowing water and rainfall intensity fitted the data better than when based on rainfall intensity solely. Models that assume a positive linear relationship between erosion and slope may overestimate sediment yield

    Study on phytoplasma causing Napier grass stunt disease (NGSD) in different farmers’ fields in Ada Woreda, Ethiopia

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    Napier or elephant grass (Pennisetum purpureum) is a perennial grass grown widely in East Africa as a fodder crop. It is being promoted in Ethiopia for use by cut and carry (zero grazing) smallholder livestock keepers. The International Livestock Research Institute (ILRI) in Ethiopia maintains a germplasm collection of Napier at its field stations in Debre Zeit and Zewai. ILRI distributed apparently clean cuttings to the farmers, however it was only recently a disease, phytoplasma was identified in these stations. Therefore, this study was initiated to detect Napier grass stunt disease (NGSD) causing agent (Phytoplasma) and the extent of its distribution in Ada woreda through Nucleic acid spot hybridization (NASH) technique, Polymerase chain reaction (PCR) and PCR- RFLP (Restriction Fragment Length Polymorphism). A total of 603 Napier grass leaf samples from 15 farmers’ field of 5 villages, ILRI/Debre Zeit gene bank, Ethiopian Institute of Agricultural Research (EIAR/Debre Zeit) and Genesis farm were screened for the presence of phytoplasma and its symptoms. Following this the effect of cutting on the prevalence of the disease was studied on Napier grass accessions 14984, 16786, 16837 and 16835. Passive transmission of the disease was also studied in a screen house with phytoplasma inoculated plants. Out of the total samples 4.3% were phytoplasma positive and only 0.8% showed the symptom. Cutting increased the prevalence of the pathogen in all accessions, however accessions 16786 and 16835 were more affected than the others. In the screen house, symptom development was correlated with the presence of Phytoplasma in 60% of the analyzed leaf samples. Out of the 19 NASH positive samples screened for the presence of phytoplasma 18 were found to be positive by PCR. PCR- RFLP result showed that digestion with Rsa I restriction enzyme had a similar banding pattern to 16Sr XI phytoplasma group found in Kenya. Therefore, the phytoplasma identified in this study seems to differ from 16SrIII group that was previously found in Zewai and Debre Zeit ILRI fields. Therefore, this study confirmed the presence of phytoplasma infection of Napier grass in Ada woreda. Further characterization of the phytoplasma using sequence analysis is needed to specifically identify the phytoplasma group

    Runoff estimation and water management for the Holetta river in Ethiopia

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    The hydrology of Holetta River and its seasonal variability is not fully studied. In addition to this, due to scarcity of the available surface water and increase in water demand for irrigation, the major users of the river are facing a challenge to allocate the available water. Therefore, the aim of this research was to investigate the water availability of Holetta River and to study the water management in the catchment. Soil and Water Assessment Tool (SWAT) modelled the rainfall runoff process of the catchment. Statistical (coefficient of determination [R2], Nash- Sutcliffe Efficiency Coefficient [NSE] and Index of Volumetric Fit [IVF]) and graphical methods used to evaluate the performance of SWAT model. The result showed that R2, NSE and IVF were 0.85, 0.84 and 102.8, respectively for monthly calibration and 0.73, 0.67 and 108.9, respectively, for monthly validation. These indicated that SWAT model performed well for simulation of the hydrology of the watershed. After modelling the rainfall runoff relation and studying the availability of water at the Holetta River, the water demand of the area assessed. CropWat model and the survey analysis performed to calculate the water demand in the area. The total water demand of all three major users was 0.313, 0.583, 1.004, 0.873 and 0.341 MCM from January to May, respectively. The available river flow from January to May obtained from the result of SWAT simulation. The average flow was 0.749, 0.419, 0.829, 0.623 and 0.471 MCM from January to May respectively. From the five months, the demand and the supply showed a gap during February, March and April with 0.59 MCM. Therefore, in order to solve this problem alternative source of water supply should be studied and integrated water management system should be implemented

    Examining out of pocket payments for maternal health in rural Ethiopia: Paradox of free health care un-affordability

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    Background: One of the components of reproductive health is maternal care. Maternal health care is supposed to be provided free of charge for public health concerns thus women have the right to get services related to maternal care free of charge at government health care facilities. But there is low utilization of the services. Only 12% of women receive ANC and only 6% get assistance of skilled health worker during delivery in Ethiopia. There are different factors for the low utilization of services. Un-affordability of services is cited as the first main reason contributing to the low utilization.Objectives: To examine the magnitude of out of pocket expenditure for maternal health series in rural Ethiopia.Methods: This study was conducted within ten randomly selected kebeles of the Butajira DSS from October 2007 to May 2008 using a cross-sectional survey design and a source population of households that expend out-of-pocket on RH services during the period of 12 months prior to the study.Results: In the study, nearly three fifth of the studied families paid out of pocket expenditures exceeding 20% of their monthly household expenditure for maternal health care seeking. Excluding expenditures for food, about 61% of them paid more than 40% of their non-food expenditure on maternal health care. Households in the lower wealth quintiles are paying greater proportion of their income (49%) than those in the highest wealth quintile who paid 19% of their income. In addition to the direct expenditures made at point of service, the indirect expenditures of reaching to the services are also found to be substantial. These indirect expenditures share 32% of ANC, 31% of obstetric care, and 44% of abortion services. Thus even if direct expenditures at point of service in public providers are assumed to be negligible, women are obliged to go to expensive private providers to reduce the indirect costs of care seeking such as waiting time. Regarding coping mechanism to respond to expenditure, households usually borrow from relatives and friends and 4.4% of the households resorted to distress sale of their assets.Conclusions: This study identified the presence of price elasticity among the poor that suggests out-of-pocket expenditure has a regressive distributional impact and poor and very poor people were expending more. On top of this, all expenses were covered from regular income which leads to catastrophic household economic crises.Recommendations: Health care providers should be evenly distributed, easily accessible and work on awareness creation on the advantages of early care seeking and preventive care. On the other hand, health care financing should also be based on the principle of cost sharing and move into prepayment schemes or insurance

    Runoff Estimation and Water Demand Analysis for Holetta River, Awash Subbasin, Ethiopia Using SWAT and CropWat Models

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    This chapter discusses the hydrology of Holetta River , Ethiopia , its seasonal variability and water management in the watershed. Soil and Water Assessment Tool (SWAT) modeled the rainfall–runoff process of the watershed. Statistical [coefficient of determination (R 2), Nash–Sutcliffe efficiency coefficient (NSE), and index of volumetric fit (IVF)] and graphical methods were used to evaluate the performance of the model. The result showed that R 2, NSE and IVF were 0.85, 0.84 and 102.8, respectively, for monthly calibration and 0.73, 0.67 and 108.9, respectively, for monthly validation. These indicated that SWAT model performed well for simulation of the hydrology of the watershed. After modeling the rainfall runoff relation, the water demand of the area was assessed. CropWat model was applied and survey analyses were performed to calculate the water demand in the area. The total water demand for the three major users was 0.313, 0.583, 1.004, 0.873, and 0.341 million cubic meters (MCM) from January to May, respectively. The average flow obtained from SWAT simulation was 0.749, 0.419, 0.829, 0.623, and 0.471 MCM from January to May, respectively. From 5 months, the demand and the supply showed a gap during February, March, and April with 0.59 MCM. To solve the gap created by the demand, alternative source of water supply should be studied and integrated water management systems should be implemented

    SWPT: An automated GIS-based tool for prioritization of sub-watersheds based on morphometric and topo-hydrological factors

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    © 2019 China University of Geosciences (Beijing) and Peking University The sub-watershed prioritization is the ranking of different areas of a river basin according to their need to proper planning and management of soil and water resources. Decision makers should optimally allocate the investments to critical sub-watersheds in an economically effective and technically efficient manner. Hence, this study aimed at developing a user-friendly geographic information system (GIS) tool, Sub-Watershed Prioritization Tool (SWPT), using the Python programming language to decrease any possible uncertainty. It used geospatial–statistical techniques for analyzing morphometric and topo-hydrological factors and automatically identifying critical and priority sub-watersheds. In order to assess the capability and reliability of the SWPT tool, it was successfully applied in a watershed in the Golestan Province, Northern Iran. Historical records of flood and landslide events indicated that the SWPT correctly recognized critical sub-watersheds. It provided a cost-effective approach for prioritization of sub-watersheds. Therefore, the SWPT is practically applicable and replicable to other regions where gauge data is not available for each sub-watershed

    Potential of Water Hyacinth Infestation on Lake Tana, Ethiopia: A Prediction Using a GIS-Based Multi-Criteria Technique

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    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 (\u3e0.08 mg L−1), total nitrogen (\u3e1.1 mg L−1), temperature (\u3c26.2 °C), pH (\u3c8.6), salinity (\u3c0.011%), and depth (\u3c6 m). These parameters were collected from 143 sampling sites on the lake in August, December (2016), and March (2017). Fuzzy overlay spatial analysis was used to overlay the different parameters to obtain the final prediction map of water hyacinth infestation areas. The results indicated that 24,969 ha (8.1%), 21,568.7 ha (7.1%), and 24,036 ha (7.9%) of the lake are susceptible to invasion by the water hyacinth in August, December, and March, respectively. At the maximum historical lake level, 30,728.4 ha will be the potential susceptible area for water hyacinth growth and expansion at the end of the rainy season in August. According to the result of this study, the north and northeastern parts of the lake are highly susceptible for invasion. Hence, water hyacinth management and control plans shall mainly focus on the north and northeastern part of Lake Tana and upstream contributing watersheds

    Understanding Farmers’ Trait Preferences for Dual-Purpose Crops to Improve Mixed Crop–Livestock Systems in Zimbabwe

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    Competition over land between food and fodder production, along with recurrent droughts and increasing population, has put mixed crop–livestock farming systems in the drylands of sub- Saharan Africa under pressure. Dual-purpose crops hold huge potential to ease this pressure and simultaneously improve food and fodder availability in these systems. We investigated farmers’ preferences for dual-purpose maize, sorghum, and groundnut traits, and analyzed linkages of stated trait preferences with production of dual-purpose crops and adoption of improved varieties involving 645 households from two districts in Zimbabwe. The three target crops cover more than 75% of households’ cropping lands. Highly preferred stated traits of dual-purpose crops include yield, disease resistance, and drought tolerance. Highly appreciated feed attributes encompass stover yield and digestibility. The adoption of improved varieties is high for maize but low for sorghum and groundnut. Trait preferences are correlated with the production of dual-purpose crops and the adoption of improved varieties of the crops. However, the strengths of these correlations differ for maize, sorghum, and groundnuts. We discuss these linkages and suggest why crop improvement programs should reconcile trade-offs between grain and feed attributes to support mixed crop– livestock systems in Zimbabwe successfully

    Modelling CD4 counts before and after HAART for HIV infected patients in KwaZulu-Natal South Africa

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    Background: This study aims to make use of a longitudinal data modelling approach to analyze data on the number of CD4+cell counts measured repeatedly in HIV-1 Subtype C infected women enrolled in the Acute Infection Study of the Centre for the AIDS Programme of Research in South Africa. Methodology: This study uses data from the CAPRISA 002 Acute Infection Study, which was conducted in South Africa. This cohort study observed N=235 incident HIV-1 positive women whose disease biomarkers were measured repeatedly at least four times on each participant. Results: From the findings of this study, post-HAART initiation, baseline viral load, and the prevalence of obese nutrition status were found to be major significant factors on the prognosis CD4+ count of HIV-infected patients. Conclusion: Effective HAART initiation immediately after HIV exposure is necessary to suppress the increase of viral loads to induce potential ART benefits that accrue over time. The data showed evidence of strong individual-specific effects on the evolution of CD4+ counts. Effective monitoring and modelling of disease biomarkers are essential to help inform methods that can be put in place to suppress viral loads for maximum ART benefits that can be accrued over time at an individual level

    Production decisions and food security outcomes of smallholder’s livestock market participation: empirical evidence from Zimbabwe

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    Smallholder market participation is an important pathway to improving the productivity and livelihoods of farm households. Despite several studies documenting the effect of market participation on crop production, relatively little is known about the effect of smallholder participation in livestock markets. We investigate effects of smallholder market participation on livestock production and household food security in Zimbabwe. Using survey data collected from 625 households and an instrumental variables strategy to address endogeneity concerns, we find that households participating in livestock markets are more likely to engage in market-oriented livestock production, use improved livestock inputs, and have better food security outcomes. While market participants are more likely to consider market conditions in their decisions, most farmers are needs-driven and cannot afford to adopt commercial-oriented behavior. Overall, smallholder livestock production systems respond to market incentives and can support food security strategies, particularly in drylands where crop production is risky
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