Environmental Planning

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The Contributions of Mensch En Fur Mensch En Foundation In Increasing Access to Primary Education In Illubabor Zone
(Addis Ababauniversity, 2001-06) Redate, Befekadu; Workineh, Tilahun (PhD)
The main objective of this study was to investigate the contribution of MfM Foundation in increasing access to primary education in Iliubabor Zone. To conduct this study, a descriptive survey was employed. For this purpose samples were taken from 6 primary schools that were supported by MfM in 6 Weredas. The research study involved four categories of sample population: teachers, students, school principals, Zone Education Department, and Wereda Education Officials and MfM Office officials. Questionnaire, interview and personal observation were the main instruments used to collect the data. Besides to support the study, documents and reports in the MfM Office and Zone Education Department were consulted. Data analysis was made by using statistical tools such as percentage and t-test to identify whether there are differences and agreements in the judgment of the respondents regarding the questions posed on the activities performed by MfM education project. The results of the findings revealed that MfM has provided support to primary education in three major areas; construction of new schools, renovation and expansion of the existing ones. It was found that the community was involved in the education project carried out by MfM by contributing money, site selection for the schools constructed and in the protection of the projects during and after its foundation. In addition to this, it was observed from the findings that support provided to primary education in Iliubabor by MfM, alleviated the problems of about 11 .4 per cent of the children's of the community to get schools near to their villages, chairs and desks and school facilities. On the other hand, it was found out that the major complaint of the community about the out come of the project was, most of the schools constructed, and renovated by MfM do not have fence. Finally, based on the major findings and conclusions drawn, the following major recommendations were for warded to meet the problem under the study
Udp-705 Housing in Urban Context informal Settlements in Addis Ababa
(Addis Ababauniversity, 2006-02) Lirebo, Daniel
Spontaneous Development of Urban Centers An analysis of the transformation process of Adama and its primary commercial centers
(Addis Ababauniversity, 2006-03) Mebratu, Addis; Berhanu, Wubshet (PhD)
Central areas in Adama have been transforming into either of two forms - blighted and decayed areas or congested and very poor quality urban environments. It seems that the problem exists as urbanization takes place in the context of relatively slow economic growth, ineffective legal and regulatory frameworks and perhaps an absence of a strong and functional social order, all leading to spontaneous urban development. The aim of this study is to understand how these urban areas became to be the way they are today. There have been a lot of studies on transformation of cities in the context of industrialized nations. It is not clear, however, whether or not these studies can explain the situation in the developing world. Attention thus far, in cities in the developing world, has been limited to amelioration of problems associated with poverty and delivery of infrastructure and social services. The quality of the urban environment was not considered as a priority. This study discusses the different stages in the transformation of central urban areas of Adama in general, and that of its commercial centers in particular, and the effects of the transformation process on the quality of the urban environment. life of the low and middle income inner-city residents of Addis Ababa. Financial, institutional and legal problems are also seen
The Archite cture of Housing the case of gerji Addis Ababa
(Addis Ababauniversity, 2007-01) Enkossa, Eyob; Singh, Gurdeep(Professor)
Currently, Addis Ababa is entangled with multi faceted problem related to urban design issues. Even though some of the issues are mentioned in the revised master plan, physical development controls and the tools & mechanisms have been found weak enough in controlling and guiding the implementation of the goals and objective of the revised master plan. Moreover, the imbalance between the increasing population number and the inadequate social & physical services has brought a significant consequence in the social, economical & physical fabric of the city. Abstract Both the unplanned & planned parts of the city are characterized as haphazardly developed, which is manifested by its poor image and design of urban environment. The fast development of the city, in specific with “Gerji”, has been developed without following a proper urban design guideline. The components of urban design have not been allocated adequately in their proper location address the need of the residents. Therefore, the architecture of housing is the most basic unit qualified for an in-depth study, which in turn can contribute its share in guiding the change rationally to create convenience, comfort, efficiency play & pleasure. The six overlapping dimensions of urban design- Morphological, Perceptual, Social, Visual, Functional and Temporal- are the everyday subject matter of urban design in the process of problem solving that must be considered simultaneously making urban design holistic. Hence, a theoretical urban design guideline should be formulated to direct the rapid development of housing since it is a critical component in the social & economic fabric of nations. Based on the findings & in an attempt to initiate dialogue among stakeholders, the study outlines a general urban design guideline for Addis Ababa, in specific with “Gerji”. The proposed conceptual guideline accommodating the dimensions of urban design with temporal changes has a goal of attaining a successful urban environment conducive to the citizens of Addis Ababa. No neighborhood has also been tested previously on the touchstones of urban design dimensions and it is the belief of the author that this thesis would make a difference in making a good urban place for people and to correct the already done mistakes. Hence, a multitude of parties are concerned, since it is an integrative joined up activity, at the heart of which is a concern for making places for people and shared rather than a particular responsibility.
Life cycle assessment of glove Leather In elico-gloving and hide unit
(Addis Ababauniversity, 2007-02) bekele, Kebede; Gessese, Nebyeleul (PhD)
The leather industry is composed of different production stages and it is characterized by using a large quantity of water and various types of chemicals .The wastes generated are categorized as a high polluting nature and usually are of solid and liquid types. Currently, except few tanneries in Ethiopia, the majorities are not aware of the environmental impacts associated with their activity. Even they are not willing to have treatment plant because of its cost for erection and running the plant. However, Elico- Gloving and Hide unit (EGHU) constructed the primary treatment plant at a cost of 8 million Birr .The plant is still functional and its running cost is around 550,000 Birr per annum. In addition to this the company is practicing on ISO-14001 .In this paper a study is performed at EGHU by implementing Life Cycle Assessment methodologies. Inventory analysis on the major inputs and out puts of the production processes in the skin tannery and impacts of the related activities are carried out. Based on the adapted impact assessment method the major problems of EGHU are identified. The possible improvement options for the existing problems are suggested. The research result shows that the implementation of the suggested improvement options will have significant benefit for the factory and for the environment. Since practicing on LCA in Ethiopia is at the infant stage, this thesis may serve as source of information to tanneries and other industries on the LCA methodology and on the existing environmental problems of the leather industry
Developing Analytical Framework that Accounts the Environment, Social and Economic Aspects of a Production System (the Case of Pthiopian leather Industries
(Addis Ababauniversity, 2007-03) Seyoum, Tewodros; Tefera, Nurelegn (PhD)
Using a life cycle Assessment, impacts of a product can be described in technical terns by assessing and quantifying inputs and outputs during the various stages of a product’s life cycle. Techniques such as Environmental cost Accounting (ECA) and Social Auditing (SA) create opportunities to describe impacts of products in social and economic terms. By combining these tools we can finally derive at a comprehensive approach to decision making. This report tries to prescribe an analytical frame work that combines tools and techniques such as LCA, ECA and SA to yield a robust and comprehensive approach in the analysis of environmental impacts. In addition case study leather industries in Ethiopian context are discussed to illustrate how such an approach can be applied and its potential improvement for sustainability by reducing environmental stress and creating economic benefit in a social balanced way
Public transportation system and its impact on urban mobility: The case of Addis Ababa
(Addis Ababauniversity, 2007-07) Kassahun, Meron; Singh, Gurdeep(Professor)
A review of relevant literatures covering the issue of public transport and its impact on mobility suggests that, a heavy reliance on this mode of transport increases the efficiency of urban mobility while at the same time easing the level of congestion. The literatures reviewed also suggest that the presence of an efficient public transport system creates a safe, sustainable and equitable urban mobility. This study evaluates the extent to which the public transport in Addis Ababa has an impact on the urban mobility of the city. It also assesses the possible strategies and approaches that can be devised to enable this mode play a significant role in mitigating the worsening level of congestion that we see in the city today. The study mainly relies on secondary data for its analysis and findings; however primary data has also been generated and analyzed with the help of sample surveys and structured interviews. The overall findings of this study revealed that despite the fact that an efficient public transport system is the best way to maximize urban mobility, in reality this mode of transport is in a critical condition to begin with in Addis Ababa. Furthermore it has been observed that increasingly heavier reliance on vehicles with small passenger carrying capacity, such as private automobiles and mini bus taxi, is resulting in congested junctions, with heavy traffic. Other factors such as the existence of only one dominant core area in the city, demand overlap that emanates from the similar working hours that are observed for almost all institutions in the city have also been identified to be the main drawbacks that need to be addressed to create an efficient public transport system in Addis Ababa. While assessing ways that can make this mode become more efficient, it was further noted that there are other factors at play, namely, the existing transport
Study on municipal solid waste management of Addis ababa university
(Addis Ababauniversity, 2007-07) Seyoum, Kassahun; Kaba, Tassisa (PhD)
The activities involved with the management of solid wastes are the control of generation, storage, collection, transfer and transport, processing and disposal of the waste with best principles of environmental considerations. Physical and chemical analyses of refuse must be known to develop and design proper management of the waste. Prior to sample collection for the analysis, preliminary site visits were made to observe the physical nature of the solid wastes in dust bins at different localities of the university, and sites were selected for sample collection. Following stratified random sampling technique and using preliminary site investigation, a total number of 8 sites were selected to get representative sample for the study. Physical and chemical analyses were done to determine selected parameters, which were considered relevant for selection of appropriate solid waste disposal method The characterization of MSW from 8 sites belonging to the three categories viz. students mess; student hostels; and offices- have shown that the quantum and physical characteristics from A.A.U. campuses show trend towards developed countries and major metropolitan cities in Ethiopia, depicting a higher standard of living. In chemical analysis a modified equation, based on percentages of compostable fractions, paper, and plastics with rags, has been suggested for estimation of energy content of the solid waste. Based on the analysed parameters, proposal for solid waste disposal of A.A.U. has been presented
Cleaner Production Assessment In The Ethiopian Alcohol Industries A Case Study In The Sebata Alcohol & Liquor Factory
(Addis Ababauniversity, 2007-07) Teffera, Belay; Assefa, Berehanu (PhD)
Sebeta Alcohol and Liquor Factory (SALF) is a sister company of National Alcohol and Liquor Enterprise (NALE). The factory was established in 1914 in Sebeta town and uses molasses as raw material for the production of potable and technical alcohols. It consists of a distillery and filling plants. Its installed daily production capacity is 2500 liters of potable alcohol and about 5000 liters of various liquors. The current production capacity was found to be on average 2100 liters of 95.7oGL potable (fine) and 250 liters of 93oGL technical alcohols per day when the factory was running normally. Water balance, material balance and energy balance were drawn only for the distillery plant for the filling section was under maintenance during sampling. The molasses, water and energy consumption were found to be 6.3 kg, 168 liters and 22.12 MJ liters per liter of 96oGL alcohol. The average BOD, COD and TDS in the wastewater were 20,866, 53,514 and 19000 mg/l respectively. The total alcohol loss from the fermentation, decantation and distillation process units was significant with the value of 13.22 %. The stillage from mash column is found a severe source of water pollution. The fermentation efficiency (78.02%), alcohol recovery at distillation unit (83.3%) and overall alcohol conversion efficiency (65.0%) were found to be low compared to values of similar technologies in India, South Africa and Brazil. The steam generation and distribution systems were studied and the boiler combustion efficiency was found extremely low (29%) resulting from excess air supply. Similarly, other sources of heat loss were identified and carefully examined The cleaner production options were generated, selected and evaluated for the distillery plant. CO2 Recovery, Cooling water recycling, lost heat recovery in the stillage and spent lee, indirect heating, generation of methane and fertilizer from stillage were considered for improving resource utilization and reducing pollution loads. Other GHK practices were recommended to bring overall efficiency in the plant
Groundwater Pollution and Public Health Risk Analysis in the Vicinity of Reppi Solid Waste Dumping Site, Addis Ababa City Ethiopia
(Addis Ababauniversity, 2007-08) Zewdie, Tesfaye; Faris, Kebede (Professor)
Background: The daily waste generation in Addis Ababa city from each individual is expected to be 0.252Kg. Current waste generation in the city is 2,940 m3/day of which 80% is colleted and disposed on dumping site every day. This open dumping site has no liner system and other groundwater pollution and public health risks control mechanism. Objective: To analyze groundwater pollution and public health risks in the vicinity of Reppi solid waste dumping site Addis Ababa City, Ethiopia. Methods: A cross sectional study was conducted in Reppi solid waste dumping site from April 10 to 25/ 2007 to analyze associated risks to the groundwater and the public health in its vicinity. For groundwater issue leachate, nearby well water and far away spring water samples were collected based on the distance difference and for public health issue. Based on standard sampling procedures 316 in the near by community and 316 from the controlled group were used for the study. Extreme care was taken to avoid alteration of chemical composition of samples during sampling. The study parameters for leachate, and groundwater quality were determined in Addis Ababa City Environmental Protection Authority and Ethiopian Geological Survey Water Laboratories. It includes physicochemical parameters such as PH, chloride, total hardness, alkalinity, TDS, TSS, DO, BOD, COD, Nitrate, Ammonia, Phosphate and trace metals. Standard methods were used for the analysis of the samples. The public health parameters were collected using pre designed questionnaires. Result and discussion: Physicochemical analysis of leachate and groundwater showed that more than 95% of parameters in nearby well water analysis is more higher than the far away spring water and much exceeded WHO drinking water quality standard. This may be due to contaminants transport from dumping site to ground water. More than 95% risk ratio Public health risks were found in the nearby residents. Conclusion: From this study we can conclude that there is an increase in risk to ground water and public health that is reported near Reppi solid waste dumping site. There fore the concerned authority should take appropriate intervention measures to groundwater and the health of the community
Mathematical Modeling of Point source Pollutants Transport in the Little Akaki River
(Addis Ababauniversity, 2007-11) Tesfaye, Natnael; Assfa, Berhanu (PhD)
Computer models are becoming increasingly important tools in every environmental management aspects. A general one dimensional water quality model has been developed for one of the most industrially concentrated and polluted river in Ethiopia; the Little Akaki River. The study covers a total of 27.4 km length along the river where pollution issues are significant. The spatial and seasonal variation of hydro-geometric properties that affect mixing and transport of chemicals in the river were estimated by correlating the river hydro-geometry in a power law model. For this 20 locations were systematically selected and field data was collected at five different months. The river have been conceptualized as 1370 equal length completely mixed computational elements; and a functional representation that includes mass transport and hydrodynamic equations were written for each computational elements. The general one-dimensional model equation was solved using the numerical technique by finite volume spatial discritization and finite difference temporal discritaization. A computational solution procedure was prepared by writing a computer program in MATLAB platform (version 7.0). The result from the model was first verified by comparing it with theoretical expectations. BOD and -DO were selected as water quality indicators and the longitudinal dispersion coefficient of the river and the kinetic parameters that affect fate of DO and BOD in the river were calibrated. The model is in good correspondence with . The performance of the model in predicting calibration data was satisfactory. After calibration the performance of the model in predicting data not used during calibration was also estimated and the result was in good agreement with these targeted water quality data. The applicability of this model as decision making tool for pollution control activities was also assessed and the result is encouraging. Recommendation; which takes into account the existing water quality problem in the study area, have been suggested for improvement and wider application the model. As works like this are an open ended; recommendations have been also given for additional research works
Utilization of Coal in Metal Industries (Case of Akaki Metal Products Factory)
(Addis Ababauniversity, 2007-11) Amare, Elfu; Gessese, Nebiyeleul (OhD)
The ever increasing prices, poor energy source mix and limited supplies of energy resource is becoming a bottle neck for sustainable development strategies of the country and to achieve the millennium development goals. To alleviate this development obstacle, the country has to find another alternative locally available resource that can substitute the imported energy source (petroleum products). One of the potential resources the country owns is coal, greater than 300 million tons of proved lignite coal reserves in its different geological parts: Yayu, Moye and Delbi as the top three major reserve areas with 229, 40-50 and 20 million tons respectively and there are more than 23 occurrence localities identified yet. This research raises and discuses the question of how coal resource in the country can be used in metal industries to substitute imported heavy fuel oils based on the current technology & demands to secure (facilitate) sustainable development of the country. This thesis therefore, is dedicated to demonstrate how coal can be used in metal industries and to propose a better system for both economic and environmental performances advantages. The energy demand and consumption of the selected factories (1) Ethiopian Iron and Steel Factory, (2) Akaki Metal Products Factory and (3) Zuqalla Steel Rolling Mill Enterprise is meet from heavy fuel oil and electric power. Except, Akaki Spare Parts and Hand Tools Share Company which uses electric power as a major source of energy, heavy fuel oil accounts the major share. For the Case Factory, the existing energy conversion system (oil fire furnace) is more flexible to use for the combustion of coal. By modifying to fluidize bed combustion, it is possible to utilize coal with better efficiency and easy control of emissions (sulfur and nitrogen oxides). Therefore, the indigenous coal can play significant role to reduce the hard currency expenditure for the imported petroleum products and improve the energy source mix of the country, more over, coal in this application area will help the country to maintain the economic development strategies and make Ethiopia self-reliant in the energy supply
Comparative Study of Macroinvertebrates and Diatoms as Bioindicators of River Water Quality in Addis Ababa
(Addis Ababauniversity, 2008-01) Addis, Taffere; Assefa, Berehanu (PhD)
A crucial element in planning water quality assessment, management and conservation programme of a river is the selection of the biological indicators used to appraise biodiversity and environmental conditions. The present study, therefore, aimed at comparing macroinvertebrates and diatoms as bioindicators of river water quality in Addis Ababa. A total of 16 sampling stations were selected along the course of Kebena River and Little and Big Akaki Rivers for qualitative evaluation of physical habitats and collection of samples used for the determination of the taxonomic composition and abundance of macroinvertebrates and diatoms. Riffle sites were chosen for sampling to make the comparison among sites easier. Standard methods of sampling and analysis of samples were employed throughout the study period. Biotic indices and multivariate analytical methods, particularly dissimilarity index, clustering and indirect ordinations were used for the analysis of the results. Macroinvertebrates diversity was extremely poor precluding comparison among sampling stations. The highest and lowest macroinvertebrates taxa richness was 5 and 0 respectively. Surprisingly, only two macroinvertebrates taxa were found at the upstream site of Kebena River, which had the least anthropogenic disturbance but with the least physical habitat quality (40.6 %). But, the highest diatom tax richness (30 taxa) was observed at this site followed by 17 taxa at the upstream of both Little Akaki and Big Akaki Rivers. The lowest diatom taxa richness (4 taxa) was observed near the discharge point of Awash Tannery, where other industries are also concentrated. Community loss index for diatom data was higher at sampling sites receiving industrial effluent. All diatom biotic indices were indicative of responses to load of pollution though it was not possible to select the index that could discriminate impacted sites from reference site clearly with such cross-sectional study. Generally, the study depicted that the rivers in Addis Ababa are highly affected by physical habitat degradation and pollution due to point and non-point sources. Based on biotic indices and multivariate analysis results, diatoms are found to be better than macroinvertebrates in indicating sources and degree of pollution as well as in discriminating reference site from impacted sites of the study area. Hence, studies that consider seasonal variations and all the factors that determine diatoms composition are recommended in order to develop a refined diatom-based river water quality monitoring tool for the rivers in Addis Ababa and other parts of the country. Furthermore, responsible authorities should take urgent ameliorative measures to improve water quality of the rivers in the city. Key words: macroinvertebrates; diatoms; bioindicator; water quality; monitoring; indices
Assessment of Non-Point Source Pollution in Lake Awassa Watershed Using the Annualized Agricultural Non-Point Source (AnnaGnps) Model
(Addis Ababauniversity, 2008-07) Amare Shamo, Demelash; T/Mariam, Ababu (PhD)
Lake Awassa watershed is a Closed-watershed located in the Central Main Ethiopia Rift valley (MER). Despite its ecological, social, and economical functions and values, the lake and its watershed have been and being inflicted by non-point sources of pollution associated with deleterious anthropogenic activities. Better management of the environment to halt the existing problem of pollution and possibly to restore the ecosystem, requires informed decision on the root causes of the problem as well as on alternative management measures. In this study, the Annualized Agricultural Non-Point Source (AnnAGNPS) model has been used for relative assessment of non-point source pollution, prioritization of the sources of pollution and formulation and evaluation of alternative management measures. The relative comparison of the AnnAGNPS model average annual output, with respect to land use, for the year 2004 showed that cultivated land with Maize and Coffee, monocropped Maize land, and Bare land are leading sources in terms of runoff yield. In addition, Bare land, Pasture poor condition and mono-cropped Maize land are top yielding in terms of sediment. Based on nutrient yield mono-cropped Maize land, cultivated land with Maize and Coffee, and cultivated land with Maize and ‘Chat’ are principal sources in terms of Nitrogen. Bare land, Shrub land with poor condition, and Pasture poor condition are leading in terms of Organic Carbon. Mono-cropped Maize land and cultivated land with Maize and Coffee are chief sources in terms of Phosphorous. Accordingly, the study identified mono-cropped Maize land, Bare land and cultivated land with Maize and Coffee as priority areas that need alternative management option to control the non-point source pollution. The study also showed that a change from mono-cropped Maize land to mixed cultivation of Maize and ‘Chat’ would result a decrease up to 78% for water and Organic Carbon, 91% for sediment and more than 95% for Phosphorus yields, while Nitrogen yield remain unchanged. A change from Bare land to mixed cultivation of Maize and ‘Chat’ would result a decrease up to 99%, 94% and 78% for sediment, Organic Carbon and water yield, respectively, while an increase up to 100% for Nitrogen. A switch from the mixed cultivation of Maize and Coffee to mixed cultivation of Maize and ‘Chat’ would result a decrease up to 81%, 75%, 60% and 35% for water, Nitrogen, sediment and Organic carbon yield, respectively, as well as a decrease of more than 85% for Phosphorus yield. Comparison of 1965 and 2004 scenarios showed that a decrease of watershed runoff by about 28%, while there is a decrease of sediment yield by about 73%. Similarly, there were a decrease of around 32%, 50% and 35% for Nitrogen, Organic Carbon and Phosphorus yields, respectively, for the 1965 scenario from that of 2004. The result of the study showed that a change in land use system can bring about significant reduction in non-point source pollution and the spatial distribution of areas in the watershed that need immediate attention
Pressure Modelling for Leakage Reduction In Addis Ababa Water Supply System Mains (Saint Paul And Rufael Sub Systems
(Addis Ababauniversity, 2008-07) Meressa, Mosissa; Assefa, Birhanu (PhD)
The city of Addis Ababa is suffering from shortage of water - the city is receiving only 48% of its demand in 2007; at the same time losing 35.73% of its supply in its distribution systems. Financial, management and technical constraints are the main bottlenecks that hamper the city from satisfying the highly growing needs of its residents while loosing such a large amount of treated water within its system. This Masters Thesis focuses on modelling water supply pressure for leakage reduction in the mains of Addis Ababa Water Supply System, especially in Rufael and Saint Paul sub systems. EPANET modelling software prepared by the Environmental Protection Authority of America is used for the purpose. In so doing, first of all water balance at both city and the stated sub-city levels was conducted to visualize the loss of water and for the purpose of indexing the leakage level, at their respective levels. Water supply for the entire city and water consumption as aggregated from individual customer bills was used to evaluate the total water loss at city level and at the sub distribution system levels, respectively. Finally, potential Environmental effects of leakage in the city water supply system are assessed. Quantifying, characterizing and modelling the factors that lead to water leakage in a city water supply system is by its nature a complex task requiring well managed network and reliable data which is scarce in Addis Ababa city water supply system. As a result, cross checking and verification of data was the most significant problem faced during the study. The paper comprises two major parts; namely Leakage Analysis part and Pressure Modelling part. It was found out from leakage analysis part that water leakage in the city was 35.67%. The ILI value was obtained to be 4.74 which is far from an ideal value of 1. Thus, there is a room for AAWSA to target for leakage reduction without affecting the current pressure system. Besides, there is similar room for leakage reduction due to excessive pressure at some nodes with pressure above the recommended maximum for leakage of 80m almost all the day as pointed out from the modelling part
Conversion of Selected Addis Ababa Municipal Solid Waste to Ethanol (Case study of Yeka sub city)
(Addis Ababauniversity, 2009-01) Taye, Ashenafi; W. Sokol(Professor)
Selected municipal solid wastes (mango and banana peels and remains) were collected, proportioned, dried, and crushed to be used as samples of this research. Principally, three experiments were carried out in series for each of the samples (one after the other), namely: hydrolysis, fermentation and distillation. The effects of factors in hydrolysis step were investigated and the global optimum combination of factor values (temperature, time and acid concentration) was set by experimentation. Factorial design of threefactors- at-two-level (23 = 8) was applied to the hydrolysis step to purely investigate the effects of hydrolysis parameters on the response variable (ethanol yield). In the analysis section, the principles of factorial design were applied to calculate the main effects, interaction effects and response tendencies. Main effects were found to be -0.125, 0.375 and 0.875 for acid concentration, time and temperature respectively. This implied that, increasing temperature level could result in relatively the highest ethanol yield than the remaining factors. Interaction effects between factors were also calculated. Accordingly, TxC and txC are -10.75 and -5.75 respectively. From this theoretical ground, the factor combination was set at 1%v/v, 60minutes and 150oC and the samples were tested at this determined point and, above and below it (three extra experiments). The highest ethanol yield was 25.5mL/50g (solution) or 24.48mL/50g pure ethanol and 26mL/50g (solution) and 24.44mL/50g pure ethanol for the first 8 and the last 3 experiments respectively. The global optimum factor combination was set at 100oC, 1%v and 60minutes for hydrolysis temperature, acid concentration and hydrolysis time respectively after analysis. It was also estimated that conversion of banana and mango peels and remains to ethanol could eliminate 16.2% of the municipal solid waste in the sub city
Engineering Geological Assessment of Granular Material from Weathered Adigrat Sandstone as Filter Material - Special Consideration to Shumbrit Dam, Western Amhara
(Addis Ababauniversity, 2009-07) Kebede, T amiru
Granular filters are used in embankment dams to prevent impermeable materials from internal erosion, while draining seepage water to prevent saturation of the downstream embankment. Such materials are usually assessed from courses of rivers or streams that contain alluvial sand and gravel materials and their suitability or performance has been evaluated using existing filter design criteria based on particle size ratios. During this work same assessment of a granular material which derived from weathering of the Lower Sandstone unit of the Mesozoic Rock Formation of Ethiopia in protecting red tropical clayey silt soil has been done. Its overall characteristics, especially those relevant to filter design, have been studied. It is also compared with respect to an alluvial source, found at relatively distant place from research site. The geometrical criteria have been mainly checked using the formulas and recommendations proposed by many scholars and standards. In addition to this, the final gradation or grain size distribution of a suitable filter material has been prepared based on the gradation of the base material following the design procedures prepared by United States Soil Conservation Service (USSCS). The residual granular material, which was sampled and analyzed for grain size distribution, nearly satisfies most of the filter criteria, but it is a little bit finer. Of the various criteria available, the USSCS method and Sherard recommendations have been given more emphasis as they consider the type of base material and accordingly proposed different approaches and ratios for design of the filter. The gradation curve for the average residual filter (averaging three samples from different localities) prepared and also checked with the empirical criteria and design rules together with one alluvial soil from the distant source. The assessment result (especially USSCS method) indicates that the residual material almost satisfies the geometrical criteria, except it becomes a little bit finer. Whereas, the average residual soil and the alluvial sediment satisfies completely both requirements of filtration and draining. As to the other characteristics of the filter, all materials (residual and alluvial) have satisfactory quality; the grains of the residual sand are dominated with quartz, while the alluvial is fragments of basaltic rocks. The behaviour of the base soil, which is related to its dispersive nature, also examined in a laboratory test. The result indicates that the base soil can be categorized as non-dispersive
Engineering Geological Assessment of Granular Material from Weathered Adigrat Sandstone as Filter Material - Special Consideration to Shumbrit Dam, Western Amhara
(Addis Ababauniversity, 2009-07) Kebede, T amiru
Granular filters are used in embankment dams to prevent impermeable materials from internal erosion, while draining seepage water to prevent saturation of the downstream embankment. Such materials are usually assessed from courses of rivers or streams that contain alluvial sand and gravel materials and their suitability or performance has been evaluated using existing filter design criteria based on particle size ratios. During this work same assessment of a granular material which derived from weathering of the Lower Sandstone unit of the Mesozoic Rock Formation of Ethiopia in protecting red tropical clayey silt soil has been done. Its overall characteristics, especially those relevant to filter design, have been studied. It is also compared with respect to an alluvial source, found at relatively distant place from research site. The geometrical criteria have been mainly checked using the formulas and recommendations proposed by many scholars and standards. In addition to this, the final gradation or grain size distribution of a suitable filter material has been prepared based on the gradation of the base material following the design procedures prepared by United States Soil Conservation Service (USSCS). The residual granular material, which was sampled and analyzed for grain size distribution, nearly satisfies most of the filter criteria, but it is a little bit finer. Of the various criteria available, the USSCS method and Sherard recommendations have been given more emphasis as they consider the type of base material and accordingly proposed different approaches and ratios for design of the filter. The gradation curve for the average residual filter (averaging three samples from different localities) prepared and also checked with the empirical criteria and design rules together with one alluvial soil from the distant source. The assessment result (especially USSCS method) indicates that the residual material almost satisfies the geometrical criteria, except it becomes a little bit finer. Whereas, the average residual soil and the alluvial sediment satisfies completely both requirements of filtration and draining. As to the other characteristics of the filter, all materials (residual and alluvial) have satisfactory quality; the grains of the residual sand are dominated with quartz, while the alluvial is fragments of basaltic rocks. The behaviour of the base soil, which is related to its dispersive nature, also examined in a laboratory test. The result indicates that the base soil can be categorized as non-dispersive
The Effect of Urban Poverty on the Scale of Deforestation: A Case from Dendi District, Ethiopia.
(Addis Ababauniversity, 2009-08) Gomoro, Geremew; Albert, Gerhard (Professor)
This paper examines the relationship between urban poverty and deforestation in the peri-urban region of Ginchi, Ethiopia. This analysis is carried out through the examination of Participatory Forestry Management (PFM) using the Five Dimensions of Urban Sustainability and incorporating them into the stages of Environmental Planning and Management. Primary research reveals that the high level of dependency of the urban poor has a direct effect on deforestation and thus any attempt to address the one problem will impact the other. However, I also found that the environmental problem was not exclusive to urban poverty but a result of weakness in all Five Dimensions. Therefore, Participatory Forestry Management is dependent on strong macro-level or other lobbying, whose success would be subject to the given context. In situations where this is not apparent, a flexible or alternate program must be implemented to address the environmental problem
Temporal Urban Growth Analysis and Potential Site Identification for A High Rising Buildings in Bahir Dar City
(2009-12) Mebratu, Haimanot
The Urbanization level and the land use dynamics of Bahir Dar is assessed in the field of GIS and Remote sensing technology for excellent understanding of the emerging growth pattern using multi temporal dataset. And the results from a study about growth trends of the urban areas in Bahir Dar are described here. The period under consideration is from 1957 to 2005. It should be noted that the internal urban growth is evaluated in a separate manner and in the pre 1957 urban centers of Bahir Dar during 1957- 2005 built up area increases from 13 hectares to 33.68 hectares. In the 1957-1984 expansion areas during 1984-2005 built up area increases from 166 hectares to 210 hectares. In the post 1984 expansion areas 363 hectares of land is used for built up. With regard to the external growth of Bahir Dar two distinctive phenomena is visible from 1957 to 1984 the city expand ten times to its size of 1957 and from 1984 to 2005 again a three times growth from its size of 1984 is observed. In addition to the above urban growth analysis a suitability model for identifying potential developable land for high rising buildings has been carried out. This analysis is based on the physical and social parameters, besides in the present research all the empirical observations, the RS imagery and the GIS analysis have been used. This has been done in an integrated conceptual and operational frame work which adds an indicative bottom up perspective to the understanding of urban growth pattern

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