Institute of Technology
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Item STREAM FLOW AND SEDIMENT YIELD MODELING: THE CASE OF ROBI JIDA WATERSHED, UPPER BLUE NILE BASIN, ETHIOPIA(Hawassa University, 2024-12-24) BELSTI DEGU NURIESoil erosion, streamflow, and sediment studies are crucial for supporting the agricultural sector through watershed planning and management practices. This study aimed to model stream flow and sediment yield in the Robi Jida watershed in the Upper Blue Nile Basin, Ethiopia, and identify best management scenarios with the records of suspended sediment concentration. The historical records of the meteorological, hydrological, and suspended sediment concentration data were used for the hydrological modeling. Sediment yield data was generated from the discharge-sediment rating curve equation using the suspended sediment concentration data. Spatially, 30*30 m DEM, 90*90m soil, and 30*30m resolution land use/land cover data were used as input for the hydrological model. In this study, the Soil and Water Assessment Tool (SWAT) model was used to model streamflow and sediment yield. The model performance in simulating streamflow and sediment yield was evaluated through sensitivity analysis, calibration, and validation processes. Period from 1994 to 2010 was used for calibration and 2011 to 2018 was used for validation. During calibration the model performance statics R2 , NSE, and PBIAS were obtained (0.80, 0.70), (0.80, 0.70), and (-4.8, 1.1) for stream flow and sediment yield respectively, and similarly for model validation R 2 , NSE, PBIAS as obtained (0.77, 0.72), (0.77, 0.71), (-4.7, -5.7) respectively. Therefore, the result indicated that the SWAT model performed well and the estimated average annual sediment yield of the Robi Jida watershed was 6.42 tons/ha/year. Based on the average annual simulated sediment yield, identified 9 sub-watersheds are critical whose annual sediment yield limit ranges above the tolerable limit were identified and prioritized for effective watershed management. Therefore applying and evaluating the different management scenarios, filter stripe 1m and 5m, vegetative contour strip, soil/stone bund, terracing, and contouring resulted in a 19.15%, 35.01%, 47.13%, 57.09%, 73.37%, and 52.81% decrease in the average annual sediment yield, respectively. Therefore, soil/stone bund and terracing scenarios demonstrated the highest potential for reducing sediment yield and showed promising results as effective best management practices in the Robi Jida watershed.Item OPTIMIZATION OF PROCESS PARAMETER BY USING SIMULATION- TAGUCHI APPROACH: A CASE OF HABTAMU SILA PLASTIC FACTORY IN HAWASSA CITY(Hawassa University, 2021-10-22) ADEME SISAY HAILEThe control of integrated manufacturing systems is usually complex. One approach that can accommodate such complexity is modeling the manufacturing processes on a computer. The primary objective of any company is to produce products with low cost. Process parameter optimization in a cost bases optimal selection of extrusion rate, setup time, feed rate, and capacity of the loading station. Besides, the use of computer simulation have been proposed and executed to tackle the issues of manufacturing cost reduction. A simulation model is an instrument in analyzing execution. Even though next studies of the outcomes of simulation can be used for investigation of design of experiment, investigation of optimum manufacturing process parameter to reduce the cost of manufacturing. Therefore, this paper deals with the optimization of process parameters in a manufacturing system to minimize the Unit Manufacturing Cost (UMC) of Un-plasticized Poly Vinyl Chloride pipes using a combined Simulation–Taguchi approach. With the new perspectives of integrated modeling, the study contributes to the body of knowledge, which also opens a new outlook for further studies. Taguchi design of experiment is useful for managing this study and L27 orthogonal array was selected. Thus, a significant factor along with their optimum combination is using Taguchi techniques to arrive at the least manufacturing cost. The results show that these methods can be useful in reducing the number of experimental trials needed to determine the best operating parameters. The results show that key parameters for optimum performance of the system are feed rate in to the hopper and the optimization of the extruder; The predicted unit cost of manufacturing the selected pipe model is 220 Birr and thus costs decreased by 28.8%., because the utilization of the machine increased by 33%, 34.6% for the worker from the actual performance. As part of the general outcome of this study, Taguchi method was helpful for reduction of unit manufacturing cost either at the product development or at process design stage and identifying optimum control parameter combinationsItem MODELING OF SURFACE WATER RESOURCES FOR WATER ALLOCATION: A CASE STUDY IN UPPER GIDABO WATERSHED, GIDABO SUB BASIN, ETHIOPIA(Hawassa University, 2023-10-28) TAMIRAT SHUKE KITAWAThe processes of population increase, urbanization, industrialization, and dependency ratio has resulted in a rapid demand increase for water resources in the developing world. Water managers in the watershed of the developing world face the increasingly difficult task of allocating the limited water resources among competing users for fulfilling their demands due to difference in available resources and water demand increment. Water resources management has limited in the Upper Gidabo watershed and there is traditional water allocation are vastly practiced. This was due to lack of sufficient awareness about available water resources and management in watersheds. Understanding the potential and use of surface water in upper Gidabo would help to increase the productivity of Agriculture and other sectors, to improve the traditional water management system. Therefore the objective of this study was to Modeling of surface water resources for water allocation under developed scenarios for maximizing overall benefits without compromising ecological requirements in the Upper Gidabo watershed in Gidabo sub basin. To achieve the aim of this study soil and water assessment tool (SWAT) model was used to determine the available surface water resources of the watershed after sensitivity analysis, calibration and validation of the model by SWAT_CUP sufi-2 algorithm. The simulated result revealed that the total average surface water potential from the watershed was 773.5 MCM annually during the study period (2021). Both the calibration and validation result for Aposto and kolla gauging station showed a good performance with a value of R2 and NSE of 0.83 and 0.65 for calibration and 0.81 and 0.6 for validation in Aposto and 0.79 and 0.62 for calibration and 0.78 and 0.61 for validation in Kolla gauging station, respectively. After this Water Evaluation and Planning (WEAP) model was used to assess water demands. To assess irrigation water requirement of the sixteen (16) crop types CROPWAT 8.0 software was used. After assessing the currently existing demands Different scenarios were also developed to determine the future water demand, and unmet demand from overall time period of 2021-2050, This scenarios namely: reference, population growth and increased water demand scenario was established to determine increasing demands under increasing human as well as Livestock population, agricultural areas and different industrial activities. The current (2021) utilization is about 110.4 MCM for consumptive use and non-consumptive (EFR) use, For EFR 10% considered from available flow to maintain ecological functioning and water resource development in the watershed. The current demands fully met with available flows and for scenarios the assessed total annual water demand may be expected to be 126 MCM, 195.1 MCM and 341.8 MCM for the reference, high population growth, and increased water demand scenarios, except increased water demand scenario the other scenarios is met fully, It is appropriate to shape more effective policies and regulations in the area for effective water resources management in reducing water shortage and achieving downstream water needs in the futureItem ASSESSEMENT OF URBAN WATER SUPPLY ADEQUACY AND EVALUATION OF HYDRAULIC INTEGRITY (THE CASE IN SHONE TOWN, HADIYA ZONE SNNPR STATE(Hawassa University, 2023-10-24) WAJANA SORSA BARATAThe importance of water to living things cannot be overemphasized. Providing adequate and sustainable water supply to the rapidly growing population in expanding and developing towns of Ethiopia is getting a challenge from time to time. The main objective of this study focuses on assessing water supply adequacy and evaluating hydraulic integrity through: analysis of water supply coverage, assessing water supply source, assessing system water loss, analysis of current & future water demands and evaluating hydraulic integrity of existing water distribution system by using WaterGEMS software simulation in Shone town, which is located at Hadiya zone, SNNP Regional State of Ethiopia. Both primary and secondary data were collected and used during study and analysis. The primary data collected includes existing pipes network GPS data and water pressure gauge readings from customer faucets. The secondary data collected includes existing water supply system information, type and number of existing mode of service, water production & consumption data, pump & BH data and financial transactions from customer billings. The methods employed during the study include, collecting and analyzing both primary and secondary data & tools used were GPS, Water GEMS Connect edition, ArcGIS 10.3, AutoCAD and statistical analysis. Based on this pipe networks were created, model developed and water GEMS simulation was conducted to test and analyze the hydraulic integrity of existing water distribution system. Accordingly, the total calculated average per capita domestic water consumption of the town for the year 2023 was 15.76 l/capita/day and the amount of water lost from system as non-revenue (NRW) was 106,963.16m3 (36%).The current year 2023 and future 2042 maximum day water demand of the town was 3899.27m3/d and 11615.11m3/d respectively but the amount of water supply from the source to the system is only 1267.20m3/d. After modeling & simulation in peak hours, the distribution system analysis showed that 25.58% of the junctions have above the maximum and 51.16% of the junctions have below the minimum operating pressure and 1.5% of the pipes have above the maximum and 43.28% of the pipes have below the minimum permissible velocity ranges respectively. Therefore, the calculated average per capita domestic water consumption only satisfies 26.27% compared to 60 l/c/d set by GTP-II of the country for category 3 urban town like Shone and the town is under sever conditions in water loss balance as compared to GTP-II target to minimize (<20%), moreover, the amount of water supplying to the system from source can only satisfies 32.51% for current and 10.91% for future demands in 2042. So this points out that availing supplemental water sources becomes the key gap to meet the current and future water demand of the town. The hydraulic analysis result of the system indicates, presence of various shortcomings to existing water supply system in terms of hydraulic integrity, these are oversized and undersized pipes, irregular flow velocity and low pressure (-22.25m H2O) and extremely high pressure values (108.96m H2O), low source water supply and improper pipe size. Moreover, performance of the model was evaluated using statistical evaluating tool. As the result, the value of coefficient of determination (R-value) in pressure calibration calculated was 0.998. Therefore, findings of this research is promised to help the stakeholders to intervene and take timely actions by upgrading the existing water supply system to meet the current and future water demand of the town.Item ASSESSEMENT OF URBAN WATER SUPPLY ADEQUACY AND EVALUATION OF HYDRAULIC INTEGRITY (THE CASE IN SHONE TOWN, HADIYA ZONE SNNPR STATE(Hawassa University, 2023-10-21) WAJANA SORSA BARATAimportance of water to living things cannot be overemphasized. Providing adequate and sustainable water supply to the rapidly growing population in expanding and developing towns of Ethiopia is getting a challenge from time to time. The main objective of this study focuses on assessing water supply adequacy and evaluating hydraulic integrity through: analysis of water supply coverage, assessing water supply source, assessing system water loss, analysis of current & future water demands and evaluating hydraulic integrity of existing water distribution system by using WaterGEMS software simulation in Shone town, which is located at Hadiya zone, SNNP Regional State of Ethiopia. Both primary and secondary data were collected and used during study and analysis. The primary data collected includes existing pipes network GPS data and water pressure gauge readings from customer faucets. The secondary data collected includes existing water supply system information, type and number of existing mode of service, water production & consumption data, pump & BH data and financial transactions from customer billings. The methods employed during the study include, collecting and analyzing both primary and secondary data & tools used were GPS, Water GEMS Connect edition, ArcGIS 10.3, AutoCAD and statistical analysis. Based on this pipe networks were created, model developed and water GEMS simulation was conducted to test and analyze the hydraulic integrity of existing water distribution system. Accordingly, the total calculated average per capita domestic water consumption of the town for the year 2023 was 15.76 l/capita/day and the amount of water lost from system as non-revenue (NRW) was 106,963.16m3 (36%).The current year 2023 and future 2042 maximum day water demand of the town was 3899.27m3/d and 11615.11m3/d respectively but the amount of water supply from the source to the system is only 1267.20m3/d. After modeling & simulation in peak hours, the distribution system analysis showed that 25.58% of the junctions have above the maximum and 51.16% of the junctions have below the minimum operating pressure and 1.5% of the pipes have above the maximum and 43.28% of the pipes have below the minimum permissible velocity ranges respectively. Therefore, the calculated average per capita domestic water consumption only satisfies 26.27% compared to 60 l/c/d set by GTP-II of the country for category 3 urban town like Shone and the town is under sever conditions in water loss balance as compared to GTP-II target to minimize (<20%), moreover, the amount of water supplying to the system from source can only satisfies 32.51% for current and 10.91% for future demands in 2042. So this points out that availing supplemental water sources becomes the key gap to meet the current and future water demand of the town. The hydraulic analysis result of the system indicates, presence of various shortcomings to existing water supply system in terms of hydraulic integrity, these are oversized and undersized pipes, irregular flow velocity and low pressure (-22.25m H2O) and extremely high pressure values (108.96m H2O), low source water supply and improper pipe size. Moreover, performance of the model was evaluated using statistical evaluating tool. As the result, the value of coefficient of determination (R-value) in pressure calibration calculated was 0.998. Therefore, findings of this research is promised to help the stakeholders to intervene and take timely actions by upgrading the existing water supply system to meet the current and future water demand of the townItem MODELING LEVEL CROSSINGS’ TRAVEL TIME AND DELAY CHARACTERISTICS OF ADDIS ABABA LIGHT RAIL TRANSIT (AA-LRT)(Hawassa University, 2019-04-17) DARIC TESFAYETraffic modeling is simplified representation of a part of traffic reality that provides a better understanding and interpreting of the complex traffic interactions. The objectives of this study is modeling level crossings travel time and delay characteristics of Addis Ababa light rail transit (AA-LRT) using simulation and mathematical models and evaluate the operational characteristics of the level crossings. In the process of achieving the objectives, the study investigate about peak period vehicle volumes, compositions, routings, LRV arriving frequency ,speed and the delays experienced. To meet the objective of this research intersection geometry data from field and traffic flow data at selected intersections is done by video recording and manual counting. In addition travel time data using light rail transit and minibus taxi is collected by traveling using these modes to a statistical number of repetitions. Suitable data inputs in forms of traffic volume, vehicle composition, vehicle routing, speed, train headway, travel time and delay at different incidences including level crossings are prepared. These suitable data inputs are introduced into VISSIM and SPSS analysis soft wares. Finally, the results were interpreted and the key research findings were presented in two types; i.e. through VISSIM simulation and SPSS statistical models. At the CMC level crossing the baseline without LRT scenario the average delay of traffic is 134.62s/veh ,the actual scenario with 00:05:41 LRV headway the average delay of traffic is 135.2 s/veh the delay increased by 0.43% and twice arrival frequency scenario the delay is 136.22s/veh with an increase in delay of 0.76% from the actual conditions. At the Sebategna level crossing the baseline without LRT scenario the average delay of traffic is 22.31s/veh ,the actual scenario with 00:06:30 LRV headway the average delay of traffic is 23.53 s/veh the delay increased by 5.47% and twice arrival frequency scenario the delay is 33.11s/veh with an increase in delay of 40.7% from the actual conditions. Additionally as observed in the mathematical model equation, the train’s travel time is dependent on running time, delay at grade intersection, open door close door time, close door start movement time and stop open door time in descending order. It is concluded that the average additional delays at level crossings increase from the base scenario and with increasing light rail crossing frequencies. In addition, delay at the level crossing is the second important variable that contributes for the variability of train travel time at peak hours.Item SIMULATION OF PILE LOADING TEST IN A LAYERED SOIL WITH VERTICAL LOADING BY USING FINITE DIFFERENCE METHOD BASED SOFTWARE(2020-10-13) BEREKET GEBRESELASSIE GIRMAYPile loading tests are usually performed in various projects to determine the ultimate pile capacity. However, the cost of running these tests and the time it takes is one of the difficulties that engineers face in current geotechnical practices. Finite difference method and finite element methods have comparable accuracy. However, finite difference method based tool was used for the analysis due to its simplicity, computational efficiency and simple structure codes. The research presents a numerical simulation of pile loading test using a finite difference program “FLAC 3D”. The chosen software is memory and simulation time efficient. It solves almost all kinds of geotechnical problems, but the only downside is that it initially takes some time to get the feel of the software, but once understood, it can solve any problem and it also supports a wide range of material models. The objective of this study is to simulate a pile load test with vertical loading in a layered soil, in order to estimate the load-settlement characteristics and to determine the effect of young’s modulus, angle of internal friction, lateral earth pressure coefficient, and the dilation angle on the load-settlement curve. Input parameters of the simulation were collected from Nib, United, and Zemen international bank's new headquarter projects. In the case of piles with incomplete data, the parameters were estimated from site experience data and/or using different equations obtained from a literature. The proposed numerical model has been validated with field data and published results provided by other studies. The validation produced good results with a minor deviation except for nib bank piles. The significant deviation in nib bank piles is due to the generalized soil parameters used in the analysis. The numerical analysis underestimated the ultimate pile capacity. However, Lateral pressure coefficient manipulation yields improved results. Underprediction of load-settlement curves of nib bank piles was due to lower young’s modulus values estimated from various equations. The study on one of the piles showed that the base resistance carries the upper hand of the total capacity. The importance of using finer mesh near high-stress gradient zones was examined and it has been found that finer mesh generated based on the developed relation produced a good performance. If the required constitutive model, initial and boundary conditions, and good quality input data are available, the proposed numerical model can be used as an alternative method for the design purpose on projects involving pile foundationsItem OPTIMIZATION OF PROCESS PARAMETER BY USING SIMULATION- TAGUCHI APPROACH: A CASE OF HABTAMU SILA PLASTIC FACTORY IN HAWASSA CITY(Hawassa Unversity, 2021-10-06) ADEME SISAY HAILEThe control of integrated manufacturing systems is usually complex. One approach that can accommodate such complexity is modeling the manufacturing processes on a computer. The primary objective of any company is to produce products with low cost. Process parameter optimization in a cost bases optimal selection of extrusion rate, setup time, feed rate, and capacity of the loading station. Besides, the use of computer simulation have been proposed and executed to tackle the issues of manufacturing cost reduction. A simulation model is an instrument in analyzing execution. Even though next studies of the outcomes of simulation can be used for investigation of design of experiment, investigation of optimum manufacturing process parameter to reduce the cost of manufacturing. Therefore, this paper deals with the optimization of process parameters in a manufacturing system to minimize the Unit Manufacturing Cost (UMC) of Un-plasticized Poly Vinyl Chloride pipes using a combined Simulation–Taguchi approach. With the new perspectives of integrated modeling, the study contributes to the body of knowledge, which also opens a new outlook for further studies. Taguchi design of experiment is useful for managing this study and L27 orthogonal array was selected. Thus, a significant factor along with their optimum combination is using Taguchi techniques to arrive at the least manufacturing cost. The results show that these methods can be useful in reducing the number of experimental trials needed to determine the best operating parameters. The results show that key parameters for optimum performance of the system are feed rate in to the hopper and the optimization of the extruder; The predicted unit cost of manufacturing the selected pipe model is 220 Birr and thus costs decreased by 28.8%., because the utilization of the machine increased by 33%, 34.6% for the worker from the actual performance. As part of the general outcome of this study, Taguchi method was helpful for reduction of unit manufacturing cost either at the product development or at process design stage and identifying optimum control parameter combinations