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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Start date: 2016End date: 2019

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    EFFECT OF SOIL BUND ON SELECTED SOIL PROPERTIES AND ASSESSING FARMERS´ ADOPTION OF PHYSICAL SOIL AND WATER CONSERVATION TECHNOLOGIES; A CASE STUDY OF FANTA WATERSHED GENA BOSSA WOREDA, SOUTHERN ETHIOPIA
    (Hawassa University, 2019-10-22) Wondimu Bekele Goba
    Land degradation is one of the major challenges in agricultural production in Ethiopia. To combat the problem various Soil and Water Conservation (SWC) measures were introduced in the country. Soil nutrients assessment is valuable for evaluating agro-ecosystem sustainability, soil degradation and identifying land management practices. This research aimed i) to evaluate the effect of soil bunds on selected soil properties (soil texture, soil organic carbon, phosphorus, potassium and nitrogen); ii) to assess the adoption of farmers and factors influencing physical soil and water conservation (SWC) technologies in the Fanta watershed. Twenty-seven soil samples at 3 slope positions were collected from soil bund and 9 soil samples at 3 slope positions were collected from no bund plots. Samples were taken at 0-20 cm, depth. Analyses were done for soil texture, soil organic carbon (SOC), available phosphorous (AP), available potassium (AK) and total nitrogen (TN). In addition, 128 households were selected from three kebeles for interview to evaluate soil and water conservation (SWC) measures adoption. The results showed that SOC, AP, and AK were significantly (p≤0.05) increased and decreased by the soil bunds and slope positions. Sand and clay fractions significantly varied with both soil bunds and slope gradient but silt and TN, was not significantly differed in no-bund plots within its slope and adjacent conserved plots. The highest values of most parameters were recorded in lower slope positions both in bund and no-bund plots and near soil bund at upslope side. Farmers differ in their willingness and ability to adopt new practices. Adoption of physical SWC was negatively correlated to age of head of household, family size, farm size, plot numbers and livestock numbers while education level, location of land, extension service and access to training were positively and significant difference. Thus, it can be concluded that soil bunds retain essential plant nutrients but its adoption was limited due to some socio-economic factors in the Fanta watershed. Therefore, Structures were not regularly maintained thus, there should be a continuous awareness creation mechanism on stakeholders and prevent cropland from open grazing. In addition, emphasis should be required on variables which negatively affecting adoption of physical soil and water conservation technologies
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    IMPACT OF CLIMATE CHANGE ON AGRICULTURAL WATER DEMAND: THE CASE OF BILATE RIVER CATCHMENT
    (Hawassa University, 2019-10-27) ZEKIWOS KEBEDE KARISA
    Climate change has impact on agricultural water demand by affecting the different climate variables such as temperature and rainfall. This study was carried out to detect the impact of the climate change on agricultural water demand under different time horizon to prevent vulnerability to climate change at Lower Bilate River sub-basin. The data used in this study were collected from National Meteorology Agency of Ethiopia, Ministry of Water, Irrigation and Electricity. Simulated climate data were obtained with using single climate model ICHEC-EC EARTH, Precipitation and temperature time series of historical and projected time period. The scenarios used were from the Eth_CORDEX_Grids archive based on RCP4.5 and RCP8.5 Scenarios. The trend analysis for the last 32 years, indicated that the impact of the climate change to changes in long-term maximum and minimum temperature is increased by 0.0395o c and 0.1380 c respectively and changes in precipitation is by the factor of the -0.83, the prediction analysis indicates that precipitation at the study area will be -35.71% and -40.18% for the year 2048 and 2080 respectively from RCP4.5 Scenarios. Whereas, based on RCP8.5 Scenarios the change in the same order will be -48.90% and -60.11%. As a result the change is expected in agricultural water demand for the selected crops at specific study area. The average irrigated agriculture water demand of selected crops Tobacco and cotton are found to be 19.01Mm3. However, this value is not kept constant as a result of the change in climate that for future time period (2017-2048) and (2049-2080) found to be 24.01Mm3 and 25.01Mm3 respectively for RCP4.5, and in case of RCP8.5 is found to be 25.33Mm3 and 28.36Mm3 respectively. Whereas, the Rain fed agriculture water demand for the crops maize and haricot bean are estimated 87.98Mm3 at the study area. As a result, the change in climate computed as 86.65Mm3 and 104.28Mm3 for the period of 2048 and 2080 respectively for RCP4.5 Scenarios, whereas based on RCP8.5 Scenarios the change will be 100.39Mm3 and 125.42Mm3 respectively
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    CORRELATION BETWEEN INDEX PROPERTIES WITH SHEAR STRENGTH PARAMETERS FOR HAWASSA SOIL
    (Hawassa University, 2017-04-23) BATAMO BELIHU
    Shear strength parameters (angle of internal friction and cohesion) are the key engineering properties of soil. In every situation finding these parameters by laboratory testing or by using advanced equipment may be uneconomical for clients during the preliminary design phase. So it is a common practice in geotechnical engineering to estimate these parameters by employing empirical equations from easily found engineering properties of soil. Correlations and empirical equations developed are site specific, and a good result will be found using them for soils from which they are developed. In this study an attempt was made to correlate shear strength parameters (angle of internal friction and cohesion) for Hawassa city soil from index properties. Detailed analysis was carried out by randomly taking thirty four samples from seven sub cities of Hawassa city. The sampling pits were dug manually using hand tools with plan area of 1.50 m by 1.50 m at depth of 3.0 m from the ground surface. From laboratory test results, most samples were found to be with very low values of density and no plasticity. The soil was classified as cohesionless soil of fine to medium sized sand with group name silty sand, sandy silt, silty, clayey sand, silty, clayey sand with gravel and well graded sand with gravel consecutively. Due to the nature of the soil, cohesion was exempted from correlation. The Influence of easily found index properties of soil on its shear strength parameter was studied, and a regression carried out for the selection of most influencing variables. This parameters identified as the grain size distribution, density, and water content of the soil
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    EFFECT OF ROAD GEOMETRY AND SPEED ON ROAD SAFFTY AND IDENTIFICATION OF HAZARDOUS ROAD SECTION (CASE STUDY ON THE WUKRO-ADIGRAT-ZALAMBESA ROAD
    (Hawassa University, 2018-10-23) RAHMA AHMED EBRAHIM
    In Ethiopia road traffic crashes are causing heavy loss of human and economic resources with the relatively low road network and motorization level. The risk is increasing with the increase in population, the road network expansion with little consideration of safety, and the increase in motorization with the vehicle fleet generally in poor conditions.This thesis deals with the most essential issue of road traffic accident related to geometric characteristics, flow and speed and identification of hazardous road section on the Eastern Tigray Zone (Wukro-Adigrat Zela'ambesa ) two lane road. The main objective of the study is to develop a prediction model for road traffic crashes occurring on a two lane road and to identify the hazardous road section.The study area has a total length of 96 km. Data such as crash data, traffic flow data, speed data, roadway characteristics and road geometry data was collected from offices and the site. Two models were developed one for the geometric characteristics of the road and flow model, the second for the speed model. The statistical analyses were performed using statistical software package SPSS version 20. The Generalized Linear Model (GLM) with Poisson regression and Negative Binomial (NB) the error structure was used to estimate the model parameters. From the two models the negative binomial model was fit to the data. The results show that number of vertical curve, number of vertical grade, no of horizontal curve, speed, shoulder width, were found to be statistically significant explanatory variables (p < 0.05) for crash involvement and when the crash rate relates to the speed it is statically significant for the crash rate. After calibration the model was validated using data from similar road on Mekelle-AbiAdi road. And the result has shown it is not validate on the similar road. For the identification of hazardous road section Empirical bays method was used. Results indicate that from the total 96 km road sections 25 sections were highly prone to accidents with PI EB values. Possible solutions are using traffic signs, user awareness campaigns, policy revisions, and permanent geometry and pavement modifications.
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    EVALUATING THE EFFECT OF IN SITU RAINWATER HARVESTING TECHNIQUES ON MAIZE PRODUCTION IN MOISTURE STRESS AREAS OF HUMBO WOREDA,WOLAITA ZONE, SNNPRS, ETHIOPIA
    (Hawassa University, 2019-10-28) WUDNESH NABA YAYA
    Rainfall fluctuations, dry spells and drought are the main constraints for rain fed agriculture. In recent years the yield and productivity of maize have been declining drastically. This is mainly attributed due to the lack of appropriate soil and rainfall management practices. This situation is envisaged can be improved under the prevailing conditions by adopting simple water harvesting techniques with the intention of raising and sustaining maize productivity. Accordingly a study was conducted to investigate the effect of some In situ water harvesting techniques on performance of maize crop with respect to soil moisture content, yield and yield components and to assess farmers' perception of water conservation techniques. To achieve the objectives of the study data and information collected through house hold survey and field experiment. The experiment was conducted in Wolaita Zone Humbo Woreda at Abela Sippa kebele, which has an irregular rain fall distribution and a prolonged dry season which leads low soil moisture availability during critical crop growth stages. The study was conducted over a period of one growing season (2010/11) using maize as indicator crop at the farmers training center of the Abela Sippa kebele. The experiment was laid out in a randomized complete block design, with three replications and four treatments. The four treatments used in the study were; Control, Targa , Tie ridge and Zai pits . Findings from this study revealed that maize grain yield and yield components, such as, grain yield, dry matter biomass, and cob length were highly significant (p<0.05) by Targa treatments, but plant height was not significant different. Soil-moisture content over the crop growing season at dry spell periods was significantly higher in Targa and Tie ridges than the control. Targa treatments increased maize yield production to (7.15 ton/ha), Tie ridge increased significantly maize production to (6.19ton/ha), Zai pits yielded (4.5ton/ha) and Control treatment yielded (4.9 ton/ha). Targa and Tie ridge treatments recorded higher net returns (29712, and 25164 ha-1) than Control (20370ha-1) and Zai (14350 ha-1) treatments. The results revealed that the rainwater harvesting technology by the community members to be a good initiative in improving agricultural practices in periods of water scarcity. But, the utilization of the technology is surrounded by various constraints. The major constraints include: labour, cost, lack of knowledge and crops planted on bunds. The findings suggest that Targa structure improved water availability during the growing season, thereby protecting crops from dry periods and it needs minimum cost, less labour power ,and easily constructed by local farmers(not require complicated knowledge)
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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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    EVALUATING SEPARATE IMPACTS OF LAND USE, LAND COVER AND CLIMATE CHANGE ON STREAMFLOW IN UPPER GIDABO WATERSHED, SOUTHERN ETHIOPIA
    (Hawassa University, 2019-12-22) DEGEFU DOGISO BUKURE
    LULC and climate change are two factors that produce major impacts on stream flow and separation of these impacts is important for water resources management as well as policy adaptation and planning for sustainable watershed development. This study was mainly focused on separating the combined and isolated impacts of LULC and climate change on stream flow reduction in upper Gidabo watershed, Southern Ethiopia. The hydrological modeling with the one factor at a time (OFAT) analysis was employed to separate hydrological impacts of LULCC from those of climate change. The SWAT model and MK statistics test were used for the study. SWAT was calibrated and validated in the watershed. The results confirmed that SWAT was a powerful and accurate model for the watershed. The model assessment metrics: NSE, R2 and PBIAS in the data were 0.90, 0.91 and 5% respectively for the calibration period and 0.73, 0.75 and 12.4% respectively for the validation period. After the calibration and validation of the SWAT model, four different scenarios were developed based on one factor at a time (OFAT) experiment. By comparing, the simulated mean annual stream flow components (Qsurf, Qlat and Qbase) results of S1 vs. S2, S3 and S4 for evaluating the effect of LULC and climate change and both on stream flow. The assessment of MK statistics result of climate change showed that precipitation and stream flow exhibited a downward trend and air temperature exhibited upward trends significantly from 1985 to 2016. Evaluation of LULCC from 1985 to 2016 showed that the changes in growth of agricultural land and built-up areas have increased by the annual rate of change 1.81% and 2.33% respectively whereas the mixed forest, evergreen forest and grassland has reduced by the rate of change 1.27%,1.84% and 0.30% respectively. The combined effects of LULC and climate change reduced mean annual lateral flow and base flow values by 7.17mm/yr. and 94.74mm/yr. respectively. The LULCC increased surface runoff by 38.29mm/yr. (56.5%) decreased lateral flow and base flow by 6.23mm/yr. (86.89%) and 26.48mm/yr. (27.95%) respectively while climate change decreased surface runoff, lateral flow and base flow by 29.47mm/yr. (43.5%),0.94mm/yr. (13.11%) and 68.26mm/yr. (72.05%) respectively. Generally, the climate change had the higher impact on base flow reduction while LULCC had higher impact on surface runoff increment and lateral flow reduction in the study watershed. Therefore, to mitigate the negative impacts of climate change combined with LULC change, local and national policymakers are encouraged to apply science-based watershed and land use planning and implement appropriate management approaches in the upper Gidabo watershed
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    ESTIMATION OF SEDIMENT YIELD AND EFFECTIVENESS OF LEVEL STONE BUNDS TO REDUCE SEDIMENT LOSS: IN GUMARA-MAKSEGNIT WATERSHED, NILE BASIN, ETHIOPIA
    (Hawassa University, 2018-10-21) ATIKILT ABERA ALEMAYEHU
    The study was conducted in Gumara-Maksegnit watershed and it’s sub-catchments to estimate event-based sediment yield and to evaluate the effectiveness of level stone bunds based on sediment loss reduction. Modified Universal Soil Loss Equation (MUSLE) was used for estimation of sediment yield. The model input parameters were collected from different sources and these are discretized and preprocessed with the help of various suitable software and tools. Finally, all six model factors were combined together using the raster calculator in map algebra to estimate the sediment yields of the study watersheds. The event-based mean observed and model estimated sediment yields were (0.5581, 0.4031 ton ha-1 ) for Gumara-Maksegnit watershed, (0.5125, 0.4194 ton ha-1 ) for treated sub-catchment and (1.0694, 1.0150 ton ha-1 ) for untreated sub-catchments respectively. The sediment losses between treated and untreated sub-catchments were highly significantly different when the sediment loss reduced by 58.8% as a result of level stone bund interventions. However, the observed and estimated sediment losses are not significantly different within a watershed. Hence, the model was well performed to estimate sediment yield in the study area with R2 (0.62, 0.72 and 0.7) and NSE (0.53, 0.71 and 0.34) for treated, untreated and Gumara-Maksegnit watershed respectively. Hence, the result showed that the Modified Universal Soil Loss Equation (MUSLE) model was well suited for reliable applications of sediment yield estimation in the study area as well as similar agroecologies
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    IMPACT OF SOIL EROSION ON CHELELEKA WETLAND AREA OF TIKURWUHA CATCHMENT, LAKE HAWASSA WATERSHED, SOUTHERN ETHIOPIA
    (Hawassa University, 2017-10-22) ASHAGO AGARO ALIT
    Environmental depletion and loss of wetland ecosystem due to soil erosion from the nearby catchment is an alarming issue because of its adverse impact on the environment that aggravated due to human pressure. This research was carried out on Tikurwuha catchment that has faced tremendous environmental problems in the last 30 years. The objective of the research was to assess the current status of soil erosion from the catchment and to detect changes on each land use /land land cover in the catchment in 1985, 2000 and 2015 time periods. The study related to estimating soil erosion from the catchment was undertaken using Revised Universal Soil Loss Equation (RUSLE) model integrating with Geographic Information System (GIS). Change in the area detected using 1985, 2000 and 2015 year satellite images. Questionnaires and focused group discussion were employed to identify major contributed factors for soil erosion in the catchment within 30 years. The result indicated that the annual soil loss in the catchment within slope classification, ranges from 0.003 to 19,886.5 t//yr and the average soil loss ranges 0.004 t/ha/yr to 13.61 t/ha/y and about 60.8% of the study area were identified to experience very low annual soil loss, whereas 21.16% of the study area experienced low annual soil losses and 18 % of the study area experienced as its high contribution for annual soil loss in the catchment. Significant change has occurred and observed in the wetland sub- catchment by analyzing three years Land sat images in the last 30 years. The areas that were covered with marsh land in 1985 were 3609.92 ha this was changed to 2441.40ha in the 2000 and this was decreased to 1651.74 ha in the 2015 and has shown 54.22% decrease from 1985 to 2015. The area that were covered with forest in 1985 was 2950.78ha and this was changed to 4409.01ha in 2000 and this was decreased to 1261.97ha in 2015 and has shown 57.14% decrease from 1985 to 2015. The area that were covered with cultivated land in 1985 was 20932ha and this increased to 31912.55 ha in 2000 and this has increased to 33080.75 ha in 2015 and it has shown 58.02% increase from 1985 to 2015. Farmers’ attitudes were also analyzed and they replied that forest degradation, agricultural land expansion and unwise use of catchments are the main causes for the decrease of wetland areas and for the soil loss in the catchmen
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    Assessment & Allocation of Transmission Losses & Costs under N-1 Contingency Condition
    (Hawassa University, 2016-08-17) Rahel Dawit
    Traditionally electricity supply industry (ESI) was monopolistic in nature with generation; transmission and distribution owned by government. Now in all over the world electricity market is restructured. All the three major areas i.e. generation, transmission and distribution are now working as separate companies namely Generating Companies (GENCO), Transmission Companies (TRANSCO) and Distribution Companies (DISCOMs). Under this environment the question of loss allocation is also very much important because no one want to bear this loss. Contingency conditions are normal practices in real power system and this brings transmission reliability margin into the picture. Further under contingency the value of losses in certain lines is increased due to extra flows in these lines. Hence transmission loss assessments, allocation and pricing with consideration of contingency are significant issues in restructured electricity market. Due to this reason a methodology for transmission loss assessment, allocation and pricing with consideration of N-1 contingent maximum flow condition has been developed. For finding contingent loss novel reliability factors is introduced. By using this factor optimal losses are calculated. After calculating these losses by using Bialek’s tracing these losses are allocated to generators and loads. After that by using MW-cost methodology transmission loss cost is allocated to the generators and demands. Sample 6 bus and IEEE 14 bus system are used for showing the feasibility of this method