Institute of Technology

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The Institute of Technology focuses on education, research, and innovation in engineering, technology, and applied sciences to support sustainable development.

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End date: 2019Subject: search.filters.subject.Ethiopia

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    LAND USE LAND COVER CHANGE DYNAMICS AND SOIL LOSS: GIS AND REMOTE SENSING BASED ANALYISIS, IN SHASHOGO WEREDA, HADIYA ZONE, SNNPRS, ETHIOPIA
    (Hawassa University, 2018-10-26) YOSEPH DEBOCH HANKORE
    The relationship between land use land cover change dynamics and soil loss over the last four decades (1973-2015) was investigated using GIS and Remote Sensing data at Shashogo Wereda, Hadiya Zone, SNNPRS, Ethiopia. In order to achieve these, satellite data of Landsat 1 MSS for 1973, Landsat 5 TM for 1986, Landsat 7 ETM plus for 2000, and Landsat 8 OLI for 2015 have been obtained and pre-processed using ERDAS Imagine 2014 software. The Maximum Likelihood Algorithm of Supervised Classification has been used to generate LULC maps. Ancillary data were used to validate the classified LULC maps. For the accuracy of classified LULC maps, a confusion matrix was used to derive overall accuracy and results were above the minimum and acceptable threshold level. For change detection statistics, cross-tabulation matrices method was employed to identify gains and losses between LULC classes. The study analyzed the magnitude of spatial and temporal LULC changes for three consecutive periods; 1973 to 1986, 1986 to 2000, and 2000 to 2015. Moreover, the soil loss from the watershed was estimated using USLE employing GIS tools. Results of the study revealed that the study area has undergone substantial LULC changes. Over the 42yrs, the aerial coverage of cultivated land was increased from 43.9 to 63.0% between 1973 and 2015. Similarly, water body and wetland were increased from 0.6 to 3.9% and 4.4 to 6.7% respectively. Settlement area which was not found in the first and second period of study years, satellite image result have 2.9% proportion in 2015 LULC classification. On the other hand, grass land, bush land, and bare land were decreased from 16.1 to 6.5%, 28.6 to 12.4%, and 6.4 to 4.5% between 1973 and 2015, respectively. Following the land use change pattern, soil loss values were increased in 2015. The estimated soil loss rate in the watershed was 14.31t/ha/yr in 2015. The findings of this study suggested that the rate of LULC change over the study period, particularly intensively cultivated land, bare land, and soil erosion problems need to be given due attention to maintain the stability of the ecosystem
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    FACILITY LAYOUT DESIGN TO EFFICIENT SPACE UTILIZATION AND INSPECTION PERFORMANCE: CASE OF MODJO DRY POR
    (Hawassa University, 2018-10-17) BONDE ASSEFA SHULISHA
    Ethiopia is landlocked country which uses the Ethio-Djibouti corridor the main outlet to the sea. However, this generates high demurrage cost at Djibouti port. To overcome these challenges, Ethiopian government established about eight dry ports in Ethiopia. From those, the Modjo dry port is large and 95 % of goods are flow through it. This makes congestion in the warehouse and terminal due to lack of suitable facility layout for inspection performance. So, this paper proposes an alternative facility layout design of warehouse. This done by using primary and secondary source of data which collected from warehouse managers, drivers, loading and unloading labors, customers of Modjo dry ports. However, the researcher use surveying, different journal, website and report from dry port as basic inputs for models to propose modified alternative layouts. The models used were classified in different levels regarding their compatibility to execute paper works as per requirement. Those were mathematical, Computer aided design model (AutoCAD) and simulation Model. The mathematical model was mainly used to calculate areas, volumes of existing and modified alternative layouts of the warehouse. The AutoCAD model was used to draw out the alternative facility layouts by feeding the input data collected from field survey by using Global Positioning System GPS and dimensions measured by using standard meter. The results of the study were validated by descriptive event simulation software which is known as any logic software. Finally, depending on the result of simulation, and model output of AutoCAD the alternative layouts were proposed. The capacity of space dedicated for existing warehouses could accommodate the 120 TEU. However, for the alternative layouts of I, II, III & IV are 564, 752, 556 & 796 TEU respectively. Depending on these results the alternative scenarios were proposed in order to mitigate the challenges facings to Modjo dry port. The contribution of this study is to realize the gaps of knowledge in using pallet racks for space utilization with aisle or passageway in the warehouse and point out the future research directions in facility layout design to efficient space utilization and inspection performance around the dry port area
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    SOIL LOSS RISK ASSESSMENT UNDER CLIMATE CHANGE AND MANAGEMENT PRACTICES: A CASE OF NERI WATERSHED, OMO-GIBE BASIN, SOUTHWESTERN ETHIOPIA
    (Hawassa University, 2019-10-22) ABEBE HEGANO HEMACHO
    Soil erosion is one of the biggest global environmental problems resulting in both on-site and off site effects. Climate change is expected to affect soil erosion based on a variety of factors, including a direct impact on soil loss by increasing precipitation amounts and erosive power. Neri watershed was chosen for this study. The objective of study is to assess soil loss risk under climate change and anticipated management practices. Revised Universal Soil Loss Equation model was applied by integrating bio physical and remote sensing data. Model parameters were computed from available data. Three Representative concentration Pathway scenarios (RCP2.6, RCP4.5 and RCP8.5) and management practices considered for estimation of annual soil loss rates. The resultant annual soil loss map under baseline condition shows the mean and total of 9.955t/ha/yr- 1 and 0.46m t/yr respectively. Estimates suggest that out of the total (46546 ha), about 32.7% % of the total area exceeded the tolerable limit and 67.3%% of the total area were below tolerable rate. The future soil loss rates are higher than the baseline period if no management actions are taken. Under no- management action scenario, the predicted the incremental rate of soil loss from (21.95%) for RCP8.5 (2051-2080) followed by 4.57% RCP4.5 (2021-2050) to insignificant decline (-0.75%) for RCP2.6 (2021-2050) compared to baseline period whereas, the other two predicted reduction. Moreover, inclusion of comprehensive management may result much higher reduction in soil loss over baseline and future condition of no action. The maximum reduction by 41.2% of its soil loss due to climate change is predicted RCP8.5 (2051-2080). The resultant soil loss map of baseline period was used in prioritization of intervention areas based on soil loss tolerance. Among eleven (11) sub-watersheds, eight and ten administrative kebeles out of nineteen are above the tolerable limit. However, watershed as planning unit, taking the proportion of soil loss to area, seven sub watersheds were identified as areas of intervention. To ensure sustainable resource use, management practice like contour cropping system complimented with terraces in agricultural fields and with giving special attention through strong policy measures to climate change, erosion minimization in non-agricultural land use classes were needed. Finaly, the study indicates a need for further study to understand the land suitability that consider the climate change
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    GROUNDWATER FLOW MODELING AND ASSESSING THE IMPACT OF FERTILIZERS ON GROUNDWATER QUALITY: THE CASE OF HORMAT-GOLINA SUB-BASIN, AWASH BASIN, ETHIOPIA
    (Hawassa University, 2019-10-23) MENGESHA TESFAW ABAY
    Groundwater is the source of water supply for different purposes including domestic, irrigation and depending on its capacity, it is suitable for industrial activities. Groundwater in many parts of the world is under risk because of increasing demands, mismanagement and contamination. All previous studies had not been explored the predicted groundwater flow dynamics in relation to climate change and anthropogenic stress, but this study has developed on the groundwater fluctuation with respect to human pressure and climate change. Visual mod flow flex 5.1 was used for simulating the groundwater flow in response to different stress periods. Groundwater flow and transport modeling in this Sub-basin have provided information about groundwater quantity as well as the quality aspect for decision makers about the groundwater accessibility. The initial head measured values in before and after irrigation season has varied to a maximum of 0.8 m. The groundwater head level in before and after irrigation season was varied from 9.3 m to 8.26 m in the Southern boundary and from 41.5 m to 38.83 m in Northwestern boundary of the Sub-basin respectively. While the predicted groundwater head and drawdown of increased pumping rate with decreased recharge rate scenario was magnify the bad effects in the Sub basin. The maximum depth of 0.27 m and 2.6 m drawdown was found in before and after irrigated season around the pumped wells respectively. The increased pumping rate with decreased recharge rate was replied to the groundwater head at the end of 2021has decreased by 2.81 min the Northwestern boundary of the Sub-basin as compared as using constant pumping rate with constant recharge rate. While decreased pumping rate with increased recharge rate was replied to the groundwater head at the end of 2021has increased by 2.23 m in the Northwestern boundary of the Sub-basin as compared as using constant pumping rate. The impacts of climate change and human pressure on groundwater have been the greatest threats in those supply wells. Decreased in pumping rate with increased recharge rate has accomplished to restore and protect the groundwater resources which is the best option for groundwater restoration and monitoring. Anthropogenic pressures including the application of fertilizers were a considerable cause of degraded groundwater quality in relation to Nitrate and Phosphate concentration with series of time. The groundwater quality has deteriorating with the applied Urea and DAP fertilizes in the selected wells of Hormat-Golina Sub-basin. Farmers have encouraged using practices that minimize the risk of groundwater pollution by carefully controlling and timing of the use of fertilizers to avoid over application.
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    PERFORMANCE EVALUATION OF SMALL SCALE IRRIGATION SCHEME IN ADDIS-ALEM, SEHARTI SAMRE WOREDA, TIGRAY, ETHIOPIA.
    (Hawassa University, 2017-10-28) ABRHA FENTAW AKALU
    Water is scarce and expensive resource which needs to be utilized in a highly productive manner for agriculture. The main objective of this study was to evaluate the performance of the small scale irrigation scheme at Addis-Alem, Seharti Samre Woreda, Tigray Regional State. The importance of performance evaluation of small scale irrigation scheme mainly for advising irrigators on how to improve their system and management practice, intervention across different system levels, and to compute irrigation seasons and technologies The scheme has command area of 60 ha during the current study time and serving about 240 beneficiaries. To achieve the aim primary and secondary data were gathered. The internal and external performances using minimum sets of performance which includes agriculture water use economical, and physical performances. In order to compute the irrigation water use efficiency of farmers at field level, nine farmer fields were identified from the irrigation scheme in the relation to their location (head, middle and tail end water users). The internal process which include conveyance, application, storage, runoff, deep percolation ratio, distribution efficiencies, and overall irrigation efficiency were used to check the performance of the irrigation scheme. The results of the analyses indicate that the conveyance and application efficiencies were found to be 51.297 and 68.07% respectively. The runoff ratio of the scheme was nil as the furrows are block end type. Deep percolation ratio in the same order of the scheme was found to 31.93%. Storage efficiency was also estimated 47.69%. Further, irrigation uniformity of98.91% was attended. From the analysis of external indicators, the output per cropped area and output per command area were found as 4545.455 and 1363.636US$ha-1 respectively. The output per irrigation supply of the scheme was 0.663 US$ m-3 . Output per water consumed in the scheme was 0.974 US$ m-3 . The water use performance of the scheme was computed, water supply and relative irrigation supply were found as 7.362.The irrigation ratio of the scheme was found to be 0.30 which means about 70% of the command area is not under irrigation during the study period. In general,, the performance of Addis-Alem irrigation scheme is low . But there is still a room for improving the performance of the scheme by resizing the main canal as well as the secondary and tertiary canals which were not adequately carrying the required irrigation water
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    FACILITY LAYOUT DESIGN TO EFFICIENT SPACE UTILIZATION AND INSPECTION PERFORMANCE: CASE OF MODJO DRY PORT
    (Hawassa University, 2018-10-07) BONDE ASSEFA SHULISHA
    Ethiopia is landlocked country which uses the Ethio-Djibouti corridor the main outlet to the sea. However, this generates high demurrage cost at Djibouti port. To overcome these challenges, Ethiopian government established about eight dry ports in Ethiopia. From those, the Modjo dry port is large and 95 % of goods are flow through it. This makes congestion in the warehouse and terminal due to lack of suitable facility layout for inspection performance. So, this paper proposes an alternative facility layout design of warehouse. This done by using primary and secondary source of data which collected from warehouse managers, drivers, loading and unloading labors, customers of Modjo dry ports. However, the researcher use surveying, different journal, website and report from dry port as basic inputs for models to propose modified alternative layouts. The models used were classified in different levels regarding their compatibility to execute paper works as per requirement. Those were mathematical, Computer aided design model (AutoCAD) and simulation Model. The mathematical model was mainly used to calculate areas, volumes of existing and modified alternative layouts of the warehouse. The AutoCAD model was used to draw out the alternative facility layouts by feeding the input data collected from field survey by using Global Positioning System GPS and dimensions measured by using standard meter. The results of the study were validated by descriptive event simulation software which is known as any logic software. Finally, depending on the result of simulation, and model output of AutoCAD the alternative layouts were proposed. The capacity of space dedicated for existing warehouses could accommodate the 120 TEU. However, for the alternative layouts of I, II, III & IV are 564, 752, 556 & 796 TEU respectively. Depending on these results the alternative scenarios were proposed in order to mitigate the challenges facings to Modjo dry port. The contribution of this study is to realize the gaps of knowledge in using pallet racks for space utilization with aisle or passageway in the warehouse and point out the future research directions in facility layout design to efficient space utilization and inspection performance around the dry port area
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    HYDROLOGIC RESPONSE TO LAND USE/LAND COVER CHANGE IN THE GENALE DAWA RIVER BASIN, ETHIOPIA
    (Hawassa University, 2019-08-06) MARTA AYE YALEW
    Land use land cover change has been one of factors responsible for altering the streamflow of the watershed on the Genale Dawa river basin leading to impacting river flows. The study mainly focused on estimating land use land cover change on streamflow. Land use land cover maps of 1986 and 2013 were obtained from Ethiopian Mapping Agency. The maximum likelihood algorithm of supervised classification was used in ERDAS Imagine 2014 software tool. A physical based, semi-distributed hydrological model, SWAT was used to investigate the impact of land cover change on streamflow of Genale Dawa River Basin gauged at Halwen. Land cover change analysis has shown an increment of cultivated land from 9.5% to 17.6%, agriculture land 9.1% to 19%, and built up areas 5.2% to 14.4%, while a decrement in the forest area from 31.15% to 19%, and water body from 7.2% to 7%, shrub land from 15.9% to 8.2%, Wet land from 8.8% to 4.9% and Grass land from 13.2% to 9.6% between 1986 and 2013. The performance of the SWAT model was evaluated through sensitivity analysis, calibration and validation. The model was calibrated using flow data from 1990 to 2001 including 2 year warm-up period and validated using data 2002 to 2007. Both the calibration and validation result show good agreement between observed and simulated stream flow with NSE and R 2 values of 0.86 and 0.88 for calibration and NSE are 0.84 and 0.85 for validation. Sensitivity analysis has shown that the curve number is the most sensitive parameter that affects stream flow of the watershed. The result of this study indicated that the mean monthly stream flow were increased by 8.5% for wet season and decreased by 3% in the dry season over 30 year’s period. As a result it might be possible to conclude that for the catchments the impacts were significant. Therefore, it can be deduced that LULC impact for the study area might be the most sensitive than the propagated uncertainty on catchment flow.
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    EVALUATION OF IMPACT OF INTERNAL EROSION ON THE STABILITY OF DAM
    (Hawassa Inversity, 2019-07-10) KETEMA TESFAYE ADUGNA
    Embankment dams encounter several problems in terms of dam safety. One of those problems is called internal erosion. This phenomenon is brought by the movement of fine particles within the dam due to seepage forces. Internal erosion represents a complex combination of several mechanisms related to the failure or near failure of dams and levees. If the dam is not able to self heal, the eroded zones will increase which will eventually cause the dam to fail. Specially if the discontinuity such us concrete conduit is there in the dam embankment the probability of concentrated flow occurrence through the embankment body is increased. The dam selected for this study Arjo Dhidhessa rock fill dam is currently under construction by MoWIE, Due to regied structure embedded in the body of the embankment dam it is related to the problem of internal erosion within the core. The impact of this internal erosion is analyzed in this thesis with the use of Finite Element Method/Analysis (FEM/A). FEA models simulate the in-situ stresses in the dam and calculate the strength. It also enables the analysis of changing hydraulic conductivity and its effect on the overall effective strength due to changing pore pressure and seepage forces. The analysis using numerical methods was performed in the program PLAXIS2D and SEEP/W while limit equilibrium analysis was done in SLOPE/W. The calculation in PLAXIS2D was performed by using the Mohr-Coulomb constitutive model. The in-situ stresses are initially calculated using gravity loading since this is the preferred method on an uneven terrain instead of a K0-calculation. Then, through a set of phases in the program, zones where erosion is assumed to have occurred are changed. These zones have a higher permeability and will thus affect the pore pressures in the dam following Darcy’s law with permeability through a set medium. The increased permeability is set to follow an increased void ratio due to loss of fine material in the core. How this increase of void ratio affects the permeability is investigated through using Ren et al. (2016) proposed equation for calculating permeability with a set void ratio. Their equation, apart from the usually used Kozeny-Carman equation, considers both effective and ineffective void ratio where the ineffective void ratios refers to the volume of pores that is immobile when flow is considered. Conduits through embankment dams are prone to seepage and internal erosion around the surrounding soil. The increased flow in the eroded zones of the core did not seem to impact the strength of the dam in much regard. The phreatic surface and thus the pore pressure did not change enough to influence the overall effective strength of the dam. It raises the question if the stability of an earth-rock fill dam will be affected due to increased pore pressure at all due to its draining properties and if it would rather fail due to increased seepage forces. Throughout design and construction of rockfill dam as much as possible fixing the conduit out of the embankment dam is recommendable to avoid the probability of concentrated flow which potential cause internal piping