125 research outputs found
Performance of specific CMIP6 GCMs for simulating the historical rainfall and temperature climatology of Lake Tana sub-basin, Ethiopia
No full textThis study aims to evaluate the performance of 7 rainfall and 6 temperature products from the Coupled Model Intercomparison Project phase 6 (CMIP6) Global climate models (GCMs) for simulating the rainfall, maximum temperature (Tmax), and minimum temperature (Tmin) climatology of the Lake Tana sub-basin (Ethiopia) during 1995 – 2014 periods from daily to annual time scales. The rational of this study is to identify the best performing GCMs for projection of future climate as well as for using those models for climate adaptation and mitigation plans in the study area. Through wide-ranging evaluation methods using the Comprehensive Rating Index (CRI) and Taylor diagram, our study contributes by highlighting the top performing GCMs across different temporal scales for precipitation, Tmax and Tmin separately. The findings indicated that EC-Earth3, MPI-ESM1-2-LR and ACCESS-ESM1-5 at daily time scale, and CNRM-CM6-1, BCC-CSM2-MR and EC-Earth3 at monthly timescale are the best performing models for simulating precipitation. The best performing models for simulating MAM (March-May) seasonal precipitation are BCC-CSM2-MR, MPI-ESM1-2-LR, EC-Earth3 while ACCESS-ESM1-5, MPI-ESM1-2-LR, and EC-Earth3 are good at for JJAS (June-September) precipitation. BCC-CSM2-MR, MPI-ESM1-2-LR, EC-Earth3 and ACCESS-ESM1-5 are best performing models for simulating annual rainfall. Conversely, MIROC6 exhibits relatively weaker performance for simulating rainfall across all the studied temporal scales. For Tmax, EC-Earth3, MPI-ESM1-2-LR, and MRI-ESM2-0 consistently performed well, while BCC-CSM2-MR is the poorly performing climate model. Regarding Tmin, EC-Earth3, BCC-CSM2-MR and MPI-ESM1-2-LR consistently perform well, while MIROC6 demonstrates weaker performance. The finding suggested that one of the best performing CMIP6 models for simulating precipitation (ACCESS-ESM1-5) did not equally perform well for representing Tmax and Tmin. In addition, the best performing model for simulating Tmax (MRI-ESM2-0) also did not perform well for Tmin. Furthermore, the best performing climate model for rainfall on a specific temporal scale did not perform well on another temporal scale. The study recommends evaluation of climate models for rainfall, Tmax, and Tmin independently at different time scales for better understanding of future climates using the best performing models for each climate variable as well as for effective climate adaptation and mitigation plans
Livelihood vulnerability of rural households to climate variability and change: An agroecological system-based approach in northwestern Ethiopia
No full textEthiopia is widely acknowledged to be extremely vulnerable to climatic variability and change. Its agricultural sector, which is particularly susceptible to risks associated with rainfall variability, represents a major source of vulnerability. Household livelihood vulnerability varies across different agroecological zones (AEZs). This research aimed to investigate farmers' susceptibility to climate variability and change in northwestern Ethiopia. A total of 405 households from three AEZs (lowland, highland, and midland) were chosen through simple random sampling. Focus group discussions and key informant interviews were also conducted to complement and validate the numerical data. To assess the household vulnerability levels, the social, economic, and environmental indicators were aggregated, and the LVI and LVI-IPCC index were employed. The study's findings indicated significant variation in livelihood vulnerability indices, profiles, and indicators across agroecological zones (AEZs). The midland AEZ exhibited low exposure, higher adaptive capacity, and low vulnerability, while the lowland AEZ showed higher vulnerability, weaker adaptive capacity, and greater exposure compared to the midland and highland AEZs. The LVI-IPCC analysis corroborated these findings, with values of 0.128 for the midland AEZ, 0.168 for the highland, and 0.180 for the lowland. The variation is due to differences in agroecological and socioeconomic factors among households. The results indicate the necessity of implementing adaptation strategies specifically tailored to the agroecological systems in the study area. Such an approach is essential for effectively reducing vulnerability among households engaged in mixed crop-livestock agriculture. Adaptation measures developed from these assessments are both applicable and relevant to local conditions, as they are grounded in the community’s long-term realities
Strategic Design of Multi-Actor Nascent Energy and Industrial Infrastructure Networks under Uncertainty
No full textInfrastructure networks, such as gas transmission and distribution pipelines, electricity transmission and distribution cables, district heating networks and carbon capture and storage pipeline networks are vital infrastructures that form the backbone of our energy system. They transport commodities (i.e. gas, hot water, electricity) from one or several sources to one or several consumption/conversion sites through dedicated pipelines and cables. These infrastructure networks are undergoing major changes due to an increasing integration of renewable sources in the energy sector and increasing adoption of CO2 emission reduction measures by carbon intensive industries. For instance, the topology of the electricity network is undergoing changes to accommodate distributed power generation and the flexibility of consumers. Likewise, new pipeline infrastructures are being deployed for transporting CO2 from industrial sources to storage sites and greenhouses. This thesis focuses on the design of nascent energy and industrial infrastructure networks: networks that still needed to be built and for which neither scope, size, nor participants were certain. It develops systematic design analysis approaches to help improve design under uncertainty by means of flexibility. There are four parts to the thesis. The first part focuses on understanding the concept of flexible design and its application to the design of engineering systems and energy infrastructure networks. The second part focuses on flexibility analysis with the objective of improving their lifetime performance in the face of uncertain design requirements. A systematic engineering design approach combining graph theory network modelling, exploratory modelling and real options is proposed to explore candidate designs, identify valuable flexibility enablers and appreciate the value of flexible design strategies. The third part considers the role of risk sharing when actors co-invest in infrastructure networks under uncertain environment. Contractual arrangements are modelled between actors as a cooperative game and analyses the effects of uncertainty. The fourth part focuses on how private and public actors may enhance desired performances when developing new energy and industrial infrastructure networks under uncertainty.The Doctoral Degrees issued upon completion of the programme are issued by Comillas Pontifical University, Delft University of Technology and KTH Royal Institute of Technology. The invested degrees are official in Spain, the Netherlands and Sweden, respectively.QC 20171002</p
Costs of testing for ocular Chlamydia trachomatis infection compared to mass drug administration for trachoma in the Gambia: application of results from the PRET study.
No full textBACKGROUND: Mass drug administration (MDA) treatment of active trachoma with antibiotic is recommended to be initiated in any district where the prevalence of trachoma inflammation, follicular (TF) is ≥ 10% in children aged 1-9 years, and then to continue for at least three annual rounds before resurvey. In The Gambia the PRET study found that discontinuing MDA based on testing a sample of children for ocular Chlamydia trachomatis(Ct) infection after one MDA round had similar effects to continuing MDA for three rounds. Moreover, one round of MDA reduced disease below the 5% TF threshold. We compared the costs of examining a sample of children for TF, and of testing them for Ct, with those of MDA rounds. METHODS: The implementation unit in PRET The Gambia was a census enumeration area (EA) of 600-800 people. Personnel, fuel, equipment, consumables, data entry and supervision costs were collected for census and treatment of a sample of EAs and for the examination, sampling and testing for Ct infection of 100 individuals within them. Programme costs and resource savings from testing and treatment strategies were inferred for the 102 EAs in the study area, and compared. RESULTS: Census costs were 108.79. MDA with donated azithromycin cost 796.90 per EA, with Ct testing kits costing 1.38 per result. However stopping or deciding not to initiate treatment in the study area based on testing a sample of EAs for Ct infection (or examining children in a sample of EAs) creates savings relative to further unnecessary treatments. CONCLUSION: Resources may be saved by using tests for chlamydial infection or clinical examination to determine that initial or subsequent rounds of MDA for trachoma are unnecessary
Prevalence of, and risk factors for, trachoma and ocular Chlamydia trachomatis infection in The Gambia and Tanzania
No full textBeliefs About Body Weight and Practices of Regulating Food and Physical Exercise Patterns of Children Among Parents in Southern Ethiopia
No full textBewunetu Zewude,1 Getahun Siraw,2 Belayneh Melese,3 Tewodros Habtegiorgis,1 Ashenafi Hizkeal,1 Mihret Tadele1 1Department of Sociology, College of Social Sciences and Humanities, Wolaita Sodo University, Wolaita Sodo town, Ethiopia; 2Department of Sociology, College of Social Sciences and Humanities, Dilla University, Dilla town, Ethiopia; 3Department of Civics and Ethical Studies, College of Social Sciences and Humanities, Wolaita Sodo University, Wolaita Sodo town, EthiopiaCorrespondence: Bewunetu Zewude, Email [email protected]: The problem of childhood obesity is often associated with cultural values of body weight which includes the belief that voluptuous body size is a sign of good health status and better parental care. We examined the beliefs and behaviors of parents pertaining to preferred body weight of children, including practices of management of feeding and physical exercise patterns of children in southern Ethiopia.Methods: Using cross-sectional survey study design, a structured questionnaire was distributed to randomly selected parents. Quantitative data were collected from 215 respondents, inserted into SPSS software, and analyzed by frequency and percentage distributions, charts, and multinomial logistic regression techniques.Results: Most (59.1%) respondents want their child’s body weight to be normal/neither fat nor thin. In addition, 58.2% of the study participants held the opinion that average body size is an indication of good health status. Furthermore, 72.6% of respondents revealed that they control the amount of food their child consumes with the aim of preventing obesity/overweight. Moreover, 79.5% of respondents encourage their children to sometimes walk on foot, instead of always relying on vehicles while 87% of them replied that they regulate the amount of time their children spend watching TV. Above all, parents’ preference of voluptuous body size of children is significantly associated with age (OR=61.52.448, P < 0.001, 95%C.I: 57– 66.14), educational status (OR = 35.605, P < 0.001; 95%C.I: 6.050– 209.524), sex (OR = 0.237, P < 0.05; 95%C.I: 0.078-0.724) and grownup area (OR = 2.869, P < 0.05; 95%C.I: 1.062– 7.749).Conclusion: Parents not only have adequate level of awareness regarding the health risks of children’s heavy body weight but also engage in the body weight management practices of their children such as by regulating the food consumption patterns of children, encouraging them to undertake physical exercises, and by being role models while doing physical exercises for themselves.Keywords: childhood obesity, body weight, food consumption, physical exercise, regulatio
Husbandry Practice and Performances of Local and Crossbred Dairy Cows in Kacha Birra District, Central Ethiopia
No full textThe study was conducted with the objective of assessing the smallholder dairy cattle production practices and constraints in Kacha Birra district, Central Ethiopia. Multistage sampling technique was used to select the study kebeles and households in the district. A total of 162 households were interviewed in the study. About 76.5% of respondent households were headed by males. About 51% of the households in the study area attended elementary education. The major feed resources available for dairy cattle as ranked by respondent households were natural pasture (first), pseudostems of enset and banana (second), crop residues (third), and improved forages (fourth). About 91% of respondents house their cattle with the family. Reproductive and productive performances of cattle in the study district were influenced by agroecology and breed of cattle. The age at first service (AFS) was 37.15 ± 0.96 months for local, 23.42 ± 0.86 for Jersey, and 23.08 ± 0.69 months for HF crosses. The overall CI of local, HF, and Jersey crosses was 24.14 ± 0.599, 12.96 ± 0.379, and 13.76 ± 1.089 months, respectively. Similarly, daily milk yields (DMYs) of local, Jersey, and HF crosses were 1.53 ± 0.332, 8.61 ± 0.433, and 9.11 ± 0.581 L/day/cow, respectively. Training programs should be implemented to enhance dairy farmers’ knowledge and improve productivity in the region
When can antibiotic treatments for trachoma be discontinued? Graduating communities in three African countries.
No full textBACKGROUND: Repeated mass azithromycin distributions are effective in controlling the ocular strains of chlamydia that cause trachoma. However, it is unclear when treatments can be discontinued. Investigators have proposed graduating communities when the prevalence of infection identified in children decreases below a threshold. While this can be tested empirically, results will not be available for years. Here we use a mathematical model to predict results with different graduation strategies in three African countries. METHODS: A stochastic model of trachoma transmission was constructed, using the parameters with the maximum likelihood of obtaining results observed from studies in Tanzania (with 16% infection in children pre-treatment), The Gambia (9%), and Ethiopia (64%). The expected prevalence of infection at 3 years was obtained, given different thresholds for graduation and varying the characteristics of the diagnostic test. RESULTS: The model projects that three annual treatments at 80% coverage would reduce the mean prevalence of infection to 0.03% in Tanzanian, 2.4% in Gambian, and 12.9% in the Ethiopian communities. If communities graduate when the prevalence of infection falls below 5%, then the mean prevalence at 3 years with the new strategy would be 0.3%, 3.9%, and 14.4%, respectively. Graduations reduced antibiotic usage by 63% in Tanzania, 56% in The Gambia, and 11% in Ethiopia. CONCLUSION: Models suggest that graduating communities from a program when the infection is reduced to 5% is a reasonable strategy and could reduce the amount of antibiotic distributed in some areas by more than 2-fold
Impacts of land use and land cover change on ecosystem service values in the Afroalpine area of Guna Mountain, Northwest Ethiopia
No full textEcosystem service changes caused by land use and land cover change (LULCC) is an important indictor and early warning of ecological changes. However, few attempts have been made to evaluate the effects of LULCC on ecosystem services in the Afroalpine highlands of Northwestern Ethiopia. Therefore, this study aimed to analyze the impacts of LULCC on ecosystem services values in the afro-alpine area of Guna Mountain, Northwestern Ethiopia. Image classification was carried out using Landsat imageries of 1995, 2008, and 2020 following Random Forest algorithm with Google Earth Engine(GEE) based on filtered sample points. A modified benefit transfer method was used to evaluate ecosystem service value (ESV) changes in response to LULCC. The results revealed that the most notable feature of LULCC in the afro-alpine area of Guna Mountain was the expansion of cropland and built-up areas at the expense of grassland, forest, and shrubland. The overall ESV of the study site was estimated at USD 46.97 × 106 in 1995, USD 36.77 × 106 in 2008, and USD 37.19 × 106 in 2020. The net ESVs of the study site declined by USD 9.78 × 106 between 1995 and 2020. The regulating service values accounted for the greatest share, accounting for over 42% in all periods, followed by provisioning and supporting service values, which accounted for over 29% and 13%, respectively, while cultural services accounted for the smallest amount of the total ESV. The ecosystem service value of food production experienced the highest increase. However, the values of the remaining 16 types of ecosystem services declined with varying degrees of reduction over the study periods. The results of this study is necessary for land-use planners and decision-makers who require site-specific information on impacts of LULCC on ecosystem service
Flexibility - For smart infrastructure planning and development under uncertainty cases of port expansions and carbon capture and storage projects (abstract)
No full textEngineering, Systems and ServicesTechnology, Policy and Managemen
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