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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RELIABILITY ASSESSMENT AND ENHANCEMENT OF DISTRIBUTION SYSTEM BY INCORPORATING RENEWABLE DISTRIBUTED GENERATION
(Hawassa University, 2016-04-27) YISHAK KIFLE
Electricity is produced and delivered to customers through generation, transmission and distribution systems. A stable and reliable electric power supply system serve customer loads without interruptions. Distribution systems deliver power from bulk power systems to customers. Distribution reliability primarily relates to equipment outages and customer interruptions. This thesis work attempts to thoroughly identify causes for power interruptions and customer dissatisfaction and discusses the design, reliability and operation and maintenance of Hawassa feeder 10 distribution networks. With recent advances in technology, utilities expect to see increasing amounts of distributed generation (DG) on the distribution systems. Reliability worth is very important in power system planning and operation. Having a DG ensures reliability improvement and may be used to increase the reliability worth. This research presents the study of a radial distribution system and the impact of placing renewable energy DG (PV, Wind) and battery energy storage in order to increase the reliability worth. The reliability improvement is measured by different reliability indices that include SAIDI, CAIDI, EENS and ASAI. The analyzed and calculated distribution reliability indices values have been compared with standard benchmark values and comparison clearly indicates that Hawassa feeder 10 distribution systems is extremely unreliable. The values for SAIDI, SAIFI, CAIDI and ASAI are 240 minutes/year, 1.5 interruptions/customer, 123 minutes/year and 99.91% respectively in a USA standard, whereas the corresponding values for the existing distribution system of Hawassa feeder 10 are 5129.002 minutes/year, 47.5205 interruptions/customer, 107.94 minutes/year and 99.02% respectively. also unavailability of energy per year is 93.706mwh. The thesis also evaluates reliability of distribution networks, including islanded micro grid cases, is presented. The network includes two types of distributed energy resources solar photovoltaic (PV), wind turbine (WT) and energy storage as back up. These distributed generators contribute to supply part of the load during grid-connected mode, but supply the high densely loaded area Arbegona load during islanded micro grid operation. The studies performed are supported with the Power Management System Software ETAP and MATLAB CODED for power output of renewable energy source.
PERFORMANCE EVALUATION OF IRRIGATION SCHEME - THE CASE OF RATTE LARGE SCALE IRRIGATION SCHEME, DASENCH WOREDA, SOUTH OMO, ETHIOPIA
(Hawassa University, 2016-08-18) BUBU HAILE BORDIE
Ratte large-scale irrigation scheme is located in the in Dasench woreda, South Nation Nationality people regional state, Ethiopia, and had a service of five years. However, the performance of the irrigation scheme has not been evaluated yet. In the present study, the performance of the scheme was evaluated by estimating water delivery performance indicators, water conveyance efficiency, water conveyance losses, and satisfaction of irrigation users. The water delivery performance were evaluated by monitoring discharge at nine selected offtakes; three each at the head, middle and tail end of the scheme command area during the crop season from April to June 2022. The water conveyance efficiency of the main and secondary canals and thus the water losses in water conveyance were estimated by measuring irrigation water flow at different locations along the canals. The satisfaction of the irrigation water users from the irrigation service received was evaluated manually at the head, middle and tail end of the irrigation scheme, and for the entire irrigation scheme. Irrigation water flow in the main and secondary canals, as well as at nine tertiaries off takes was measured using float velocity method and 3-inch Parshall flume. The data were analyzed using CROPWAT 8.0, ARC GIS software, and Microsoft Excel. The analysis of internal performance indicators showed that the conveyance, application, storage, and overall irrigation efficiencies, and distribution uniformity were 57.3 %, 63.6 %, 88.17 %, 36.2 %, and 88.6% respectively while the deep percolation ratio is 35.7 %. respectively. The loss in conveyance was unavoidable unless the canal was lined or could be minimized with better canal management activities. Approximately 35.6% of beneficiaries express satisfaction with the irrigation services provided. It was generally found that the irrigation service provided to the user was insufficient, and the program's intended beneficiaries did not receive the benefits. Rearranging WAUs, improving user capacity, and optimizing water delivery scheduling. In summary, in order to optimize irrigation and water management, it is crucial to give careful consideration to converting unlined canals to lined ones and to exchanging water use management best practices from various irrigation projects that enhance the scheme's performance
Assessment & Allocation of Transmission Losses & Costs under N-1 Contingency Condition
(Hawassa University, 2016-10-12) 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
T E I CAPM T O F AL N U D S /E LAN OC D V RE HC NA EG ON RESER V RIO ES ID M NE TAT OI .N SAC( E FO TEKE EZ RDYH O P O D REW AM)
(Hawassa University, 2016-10-12) T KLEWE NY I T LKE U HAB A
W dehsreta si eredisnoc d ot eb ht e aedi l tinu of r m na ag neme t fo the tan u ar l uoser r sec . Ex oitcart n fo sretaw h de ap r retema s nisu g (GI )S dna esu of lacitamehtam sledom si eht ruc r tne dnert f ro hy lord og ci ev noitaula fo .sdehsretaw lioS noisore si a suoires taerht ni t eh ekeT ze sretaw h .de ofeD r ,noitatse evo rg ar iz ng, dna roop dnal am an tnemeg ca c ele r deta eht ar te fo noisore eud ot ht e tcapmi fo dnal esu dnal revoc ahc n eg . oT leved op evitceffe e noisor lortnoc snalp dna to eveihca snoitcuder ni ,noitatnemides ti si i tnatropm ot uq a itn fy eht tnemides yi dle dna itnedi fy ra e sa aht t era high srotubirtnoc of tnemides ta rcim o- taw re dehs level dna ov re l ra eg ar sae . In siht uts dy SW TA oS( il dna W reta tnemssessA )looT h gniva na ecafretni htiw rA cG SI erawtfos saw desu ot etamitse tnemides yi dle dna itnedi fy laitaps noitubirtsid fo tnemides y dlei ni eht .dehsretaw hT e ledom saw lufsseccus ly detarbilac dna tadilav ed rof derusaem rts e ma wolf dna s dednepsu tnemides noitartnecnoc ta alihceY gauging .snoitats ehT wolf itarbilac on dna noitadilav luser t dewohs taht edom l ep rfo cnamr e lave u noita scitsitats oc e tneiciff of d mrete i noitan R( 2 ) dna N hsa - effilctuS ledom ffe i neic cy (E ))SN we er ni eht ac elbatpec range R( 2 ni the ar nge 98.0 dna 8.0 7, SNE ni ht e egnar fo 38.0 dna )47.0 . oslA eht dednepsus tnemides noitartnecnoc ta lihceY a gauging snoitats R2 68.0 dna 8.0 4, SNE of 8.0 2 dna .0 78 rof oitarbilac n dna v .noitadila sihT setacidni taht eht bo s re v de seulav ohs w g doo agr tnemee htiw detalumis v eula of r b hto wolf dna tnemides y .dlei The om d le noitciderp re stlus detacidni taht tuoba 50.21 % fo eht aw t dehsre ra e sa ev ry es v ere ly edore d wi ht unna la tnemides aol d ar nging f mor 2 .9 54 ot 3 63.3 ah/senot /yr na d tuoba .42 67% fo the wa dehsret a er a sah es ver le y e noisor tiw h nna u la tnemides daol ar nging 24. 79 ot 29 5. 3 t ah/ /yr. T eh launna eva ar ge tnemides yi dle fo ht e taw e hsr ed saw 71 53. ah/t /yr of r eht dnal su e dnal evoc r pam fo 0102 . ehT tluser fo eht uts dy dluoc pleh d nereffi t dlohekats e sr ot ppa tnemelpmi dna nalp r taw dna lios etairpo e c r o tarts noitavresn eg ni sei t sretaw eh h .
RESOURCE POTENTIAL ASSESSMENT AND OPTIMAL DESIGN OF PV/WIND/BATTERY/ DEISEL GENERATOR BACK-UP HYBRID ENERGY SYSTEM FOR REMOTE AREAS
(Hawassa University, 2016-10-22) MESFIN JARISO
Off grid hybrid systems have been attracting to supply electricity to rural areas in all aspects like, reliability, sustainability and environmental protections, especially for communities living far in areas where grid extension is not appropriate. Hybrid renewable set-up indicates that combinations based on the renewable sources could be applied simultaneously to supply energy in the form employed in an off-gird supporting with battery storage and diesel generator as backup systems. In this thesis photovoltaic-wind turbine-battery bank and diesel generator have been optimally sized, simulated and optimized for the rural community of Addis Boder village in the southern regional State, Ethiopia. Primary load demand of 142KWh/day, peak load of 26kW, deferrable energy is about 27kWh/day, and deferrable peak load of 3.6kW was involved during optimization of the power system. Well known HOMER modeling tool have been used to design the off-grid system. Solar and Wind energy are considered as primary sources to supply electricity directly to the load and to charge battery bank when excess generation is happened however in peak demand times diesel generator could also be engaged. Regarding solar energy potential there is no accurately recorded solar radiation database in the country, instead only sunshine hour data was available. Empirical formulas are used to estimate the solar radiation from available sunshine duration data. This result is compared with the data collected from NASA and it is found to be nearly the same. Consequently, for this study the calculated solar radiation is used for modeling the hybrid system. During the design of this power system set-up, the simulation and optimization was done based on the electricity load, climatic data sources, economics of the power components and other parameters in which the NPC has to be minimized to select an economic feasible power system. The results obtained from the software give numerous alternatives feasible hybrid systems with different levels of renewable resources penetration which their choice is restricted by changing the net present cost of each set up Power schemes with less NPC, less COE, higher renewable fraction, less capacity shortage, smaller excess electricity and minimum fuel consumption would be suggested as optimum system. It is concluded that besides electricity provisions, the role of a standalone hybrid system in protecting the environment from degradation, the improvement of life of people living in rural area, development of clean energy, and the future situation regarding fossil fuel sources should be taken in to account. Taking these issues into account the free solar and wind energy of the country should be utilized to improve the quality of life of the communities living in rural areas
HYDRAULIC MODELING AND FLOOD MAPPING OF HAROSHA RIVER WITH HEC-RAS AND HEC-GeoRAS MODELS IN TIGRAY, ETHIOPIA
(Hawassa University, 2017-03-10) MULUGETA TAREKE ABEBE
The Harosha river catchment is found in Tigray region in Raya Valley. This study area is surrounded by Waja and Tumuga catchment in the south and Harosha, Limeat and Harle catchment in the North and also it is the upper south part of the Raya valley catchment. The area is also dominated by undulating terrain with relatively steep to moderately steep and flatter slopes in the downstream of the catchment. Harosha flood plain has been vulnerable to high flooding from rainfall during rainy season. Also the main causes of these damages are land use changes from years to years and the main objective of this study is to estimate peak flood for various return period and prepare flood inundation mapping that can be used as decision support system for future intervention. The data used for this study was annual daily maximum rainfall, DEM, land use land cover map, and soil map and the flood frequency analysis of annual maximum daily rainfall was analyzed. The SCS rain fall-runoff method, HEC-RAS, HEC-GeoRAS and ArcGIS environment are used to determine the peak flood for different return periods. The simulation result for return period of 5, 10, 25, 50 and 100 year floods magnitude are 347.4, 383.7, 420.8, 443.6 and 463.1m 3 /s respectively. The maximum flood hazard and flow depth maps for a return periods of 5, 10, 25, 50 and 100 year are 84.6 and 3.36; 86.1 and 3.84; 86.9 and 4.35; 87.1 and 4.91; and 87.7 hectare and 5.89 m respectively with a maximum velocity of 4.6 m/s.
COMPARATIVE PERFORMANCE EVALUATION OF IRRIGATION SCHEMES: A CASE STUDY OF MAI-SHAWSH AND MIDMAR SMALL SCALE IRRIGATION SCHEMES, IN MEREB SUB-BASIN, NORTH ETHIOPIA
(Hawassa University, 2017-03-21) GUESH HAGOS ASRESU
This study tries to evaluate the performance of small scale irrigation schemes using comparative indicators at Maishawsh and Midmar schemes, Mereb Sub basin, North Ethiopia. This study area has poor water management practice and not evaluated before using comparative performance indicators. To address the objectives of irrigation water use efficiency and on-field irrigation management performance of this study was field measurements related to canal discharge, moisture content determination of the soils, measurement of depth of water applied to the fields using two inches parshal flume, group discussion and informant interview to establish the cost of production and the price produced. The result of this study revealed that, the conveyance efficiency for Maishawsh scheme was 98.95%, 91.03%, and 75.21%, respectively for main lined, secondary lined and tertiary unlined canals of the scheme, and for Midmar scheme, it was 76.89% which was an earthen canal. The computed application, storage, distribution and overall scheme efficiency values are 60.8, 64.2, 93.40 and 46.7% for Midmar while they are 56.8, 70, 94.2 and 42.7% for Maishawsh schemes, respectively. The comparative indicators of agricultural outputs such as land productivity measured as outputs per unit command area and outputs per unit irrigated area are 3461.58 and 3512.8 US$/ha for Midmar while 3120.91 and 3032.46 US$/ha for Maishawsh respectively. The water indicators such as output per unit irrigation supply and Output per water consumed are 0.36 and 0.61 for Midmar while they are 0.25 and 0.54 US$/m3 for Maishawsh schemes respectively. The water supply indicators measured by, relative water supply and relative irrigation supply gave 1.8 and 1.85 for Midmar while they are 2.29 and 2.37 for Maishawsh schemes respectively. This implied that the amount of water supplied was sufficient for the water demand of both schemes. The original irrigable and command area was declined by 2% from the actual irrigated area in Midmar scheme. However, the actual irrigated area was expanded by 3% and 6% from original irrigable and command area in Maishawsh scheme respectively. The financial indicators measured by gross return on investment and financial self sufficiency for Midmar are 91.5 and 69% while they are 91 and 77% for Maishawsh respectively. Based on this result, Midmar irrigation scheme was slightly better than Maishawsh, the reason might be good water management at field level and Midmar water users pay for what they have consumed
Reactive Power Compensation and Harmonic Mitigation of Power Distribution Network Using Shunt Active Power Filter Based P-Q theory (Case study: Hawassa substation-2)
(Hawassa University, 2017-04-09) Tahir Kedir
Traditionally, the harmonic distortion and reactive power has been reduced using passive LC filters. However, the application of passive LC filters for reactive power compensation and harmonic mitigation results in parallel resonances with the network impedance. It is poor flexible for dynamic compensation of different frequency harmonic components.This work presented a scheme for reactive power compensation and harmonic mitigation of Hawassa substation-2 using shunt active power filter(SAPF), which is based on instantaneous p-q theory. The filter is identified, it automatically adapts to changes in the network and load fluctuations to mitigate the harmonics and reactive power issues. It is able to produce almost unity power factor and mitigate the total harmonics distortion (THD) to meet specified power quality standards. The performance of the SAPF depends mainly on the p-q theory to compute reference current and hysteresis band current controller to generate pulses for switching pattern of the inverter. The advantage of instantaneous p-q theory shows that it is instantaneous and works in time domain. MATLAB/Simulink computer simulation (version R2016a) is used as a simulation tool for this study. The simulation results before and after the compensation is compared to specified IEEE 519-1992 power quality standards.In three phase, three wire configurations, the result shows that THD in the load current is reduced from 37.46% to 3.56% and THD in the source voltage is reduced from 26.91% to 2.74% and power factor is improved from 0.869 to 0.949 under non ideal voltage source conditions while the reactive power is reduced from 1,178.04KVAr to 746.05KVAr
PERFORMANCE EVALUATION OF FURROW IRRIGATION IN BELLES SUGAR DEVELOPMENT PROJECT SUGARCANE FARM LEVEL, ETHIOPIA
(Hawassa University, 2017-04-29) ADUGNAW ASEFAW NIGATU
Evaluation of farm irrigation system plays a fundamental role in improving surface irrigation and in providing information used to advice irrigators how to improve their system operation. Furrow irrigation is one of the common methods of applying water to sugarcane at Belles sugar development project Sugarcane Plantation. The plantation is facing problems with respect to irrigation water management. This study was initiated with the objectives of evaluating the performance of furrow irrigation system at a farm level. To evaluate the performance of furrow irrigation system, a soil laboratory and field measurements (field layout, furrow geometry, time of cutoff, discharge) are made. The soil infiltration parameters „a‟, „k‟ and „fo‟ for each irrigation event are determined based on a two point approximation to volume balance method that incorporated modified Kostiakove Lewis infiltration function. Statically comparison of models outcome found the Win SRFR simulated model values provides good fitter than the SIRMOD simulation values to the estimated values. The analyses of the performance of the furrow irrigation in terms of application efficiency (Ea), distribution efficiency (Du), storage efficiency tail water Ratio (TWR), and Deep Percolation (DP) were done and found to be, the average application efficiency 62.1%, 65.3% and 68.5% for SIRMOD, estimated and WinSRFR simulated values; distribution efficiency 90.4%, 92.4% and 95.5% for estimated, SIRMOD and WinSRFR simulated value; storage efficiency 24.1%, 26.4% and 32.8% for SIRMOD, WinSRFR simulated and estimated values; TWR 31.2%, 34.2% and 37.9% for WinSRFR, estimated and SIRMOD simulated values, respectively and deep percolation ratio for all estimation is null. From the sensitivity analysis furrow slopes are higher sensitive than other parameters on influencing the application efficiency. The effects of furrow lengths are highly influencing on TWR. The effect of discharge influence on the storage efficiency also high with compared to others whereas the time of cutoff found affect the distribution efficiency
W YTIVITCUDORP DNA DLEIY ER S NOP SE FO NOINO DNU RE LLUF DNA ICIFED T NOITAGIRRI NI W RETA S ECRAC AERA , M OKERA ,ADEROW ET IPOIH A
(Hawassa University, 2017-07-06) KE ARD LA AW BELA UH SSEN
hserF retaw si acs r ec in ynam strap fo ht e dlrow dna nimoceb g a labolg a .adneg erutlucirgA si eht tsegral gnoma s tce o sr hcihw era snoc u gnim eguh hserf retaw . ehT sevitcejbo fo siht duts y erew ot evorpmi larutlucirga retaw ytivitcudorp a dn etagitsevni eht dleiy esnopser fo noino porc ot retaw .ticifed ehT dohtem deyolpme pmocne a sess dleif tnemirepxe ni dezimodnar telpmoc e kcolb ngised ( BCR D) htiw nevele stnemtaert na d eerht .snoitacilper ehT stnemtaert :erew lluf noitagirri ( %0 ticifed sa lortnoc ), %52 fo CWR ticifed tuohguorht org wing %05,nosaes fo CW R ticifed tuohguorht worg i gn ,nosaes dna eno p doire ticifed stnemtaert (25% dna %05 fo CW R ticifed ta in laiti , ,tnempoleved dim dna etal s egat s). ehT xe p tnemire saw deirrac tuo ta okeram aderow nrehtuos .aipoihtE stluseR dewohs taht secnereffid ni rri i tag noi retaw tnuoma yltnacifingis tceffa yponac ,revoc blub dleiy dna a evob dnuorg ssamoib fo .noino ehT umixam m elbatekram dleiy saw ac deriuq morf ylluf detagirri tnemtaert (T1) w cih h si 39.91 ah/t dna ht e muminim elbatekram yi dle saw deniatbo morf 3T ( %05 of CWR cifed it guorht tuoh org w ni g osaes n) hcihw si 01 13. t/ .ah 01T ( %05 fo C WR de ticif ta im d egats ) wohs ed eht muminim sevrah t xedni ( 6.0 8) na d 4T dna 7T ( %52 fo CWR ticifed ta ni laiti dna etal segats itcepser ev yl ) ewohs d eht mumixam .xedni hT e tsewol IH i detacidn taht retaw ticifed ta dim ts ega sesuac hgih leiy d .noitcuder ehT ma umix m porc retaw dorp u ytivitc ( 9.4 8 m/gk 3 ) saw bo s vre ed ta 3T ( 05 % fo CW R ticifed tuohguorht worg i gn osaes n) dna eht muminim ( 22.3 m/gk 3 ) saw o devresb ta 01T (50% o f CWR ticifed ta dim ts age). ehT tsegral retaw gnivas htiw s tnacifingi dleiy noitcuder aw s deniatbo ta 3T .Y dlei esnopser rotcaf ( yk ) acidni t de taht noino saw evitisnes dleiy( uder ced) rof retaw sserts ta tnempoleved dna dim htworg st .sega %05 fo CWR d ticife ta eno doirep serts s stnemtaert dewohs k 1>y , hcihw setacidni eht s ne s ytiviti fo eht o noin porc f ro hgih retaw sserts . ehT cimonoce sisylana i detacidn taht eht ixam m mu lanigram etar fo nruter saw deniatbo ta T 11 (50% fo CWR d ticife ta eht etal gats e) htiw a ten emocni fo 077,801 ah/rrib dna a lanigram tar e fo nruter 9.2765 .% ehT r ,erofe 11T ( %05 fo CWR ticifed ta etal s egat ) is yllacimonoce lbaiv e metsys fo noino noitcudorp htiw ingis f tnaci etaw r gnivas dna fi sremraf ta siht latnemirepxe etis pa e
PERFORMANCE EVALUATION OF TSILWE SMALL SCALE IRRIGATION SCHEME IN GABA CATCHMENT ENDERTA DISTRICT, TIGRAY REGION
(Hawassa University, 2017-07-12) MAMUYE ADISU YIHDEGO
This research (study) was conducted to evaluate the performance of Tsilwe SSIS in Enderta district, Tigray Regional State, Ethiopia. The performance of Tsilwe SSIS was not appraised since its operation. Therefore, this study was carried out to evaluate the performance of Tsilwe SSIS using Internal and external performance indicators. This study used primary and secondary data for assessing the irrigation performance. The primary data collected includes field observation, soil samples to characterize the soil in terms of physical characteristics and discharge measurement at main and field canals. Secondary data collected were total yield, area irrigated, crop type, and climate data. CROPWAT 8.0 model was used to calculate ETo and the crop water requirement. The analysis of internal performance indicators showed that the conveyance, application, storage, overall irrigation efficiencies and distribution uniformity were calculated and the results were 93.5%, 71.1 %, 60.2 %, 66.6 % and 87.2 % respectively. The analysis of water related indicators such as RWS and RIS were found to be 0.88 and 0.85 respectively. Since value of RWS and RIS is less than one this indicated that the total water supply is not enough to meet the crop demand and the WDC for Tsilwe irrigation system was calculated as 0.7, since this is less than unit that indicates the canal capacity is insufficient to get the peak consumptive requirement. Agricultural related indicators such as output per unit irrigated area is 153958.6 birr/ha and the output per unit command area is 95860.99 birr/ha. Water productivity indicators such as, Output per unit water consumed and Output per unit irrigation water supplied are 42.2 birr/m3 and 1.83 birr/m3 in TSSI scheme respectively. Based on the results obtained can be concluded that the water related indicators results were below the standard while the agriculture production indicators are found to be reasonable
COMPARATIVE PERFORMANCE ASSESSMENT OF MOJO ASHA AND ADANO SMALL SCALE IRRIGATION SCHEMES IN EAST HARARGHE ZONE, OROMIA REGION
(Hawassa University, 2017-08-06) EBSA MUSTEFA HAKIM
This study attempts to assess and cross-compare the performance of two small-scale irrigation schemes found in Oromia regional state namely, Mojo Asha and Adano irrigation schemes using comparative indicators. After collection of the valuable data from various sources, data analysis techniques were implemented for evaluating their performance using selected performance indicators such as conveyance efficiency, Application efficiency, system efficiency, water productivity and land productivity. The results showed that the average conveyance efficiencies of the two schemes were 83.41 % and 76.78 % at Mojo Asha and Adano respectively. It was lower at Adano than Mojo Asha scheme due to poor water management and irrigation structures’ deterioration. The maximum value of application efficiency found in downstream field of Mojo Asha scheme were 65.43 % and the minimum value was found in the Adano scheme at upstream field 40.45 % due to much amount of water was applied to the field without considering water requirement. The results of water use performance also indicated that the ratio of annual relative water supply were1.09 and 1.19 at Mojo Aasha and Adano schemes respectively, and ratio of annual relative irrigation supply were 1.12 and 1.27 at Mojo Aasha and Adano schemes respectively. The result indicated that water distribution is not tightly related to crop water demand or applying more than the demand. From analysis of agricultural performance the output results showed that the outputs per unit irrigation supply were 8.62 and 7.92 Birr/m3 at Mojo Asha and Adano schemes respectively. Whereas output per unit irrigation delivered were 10.78 and 9.70 Birr/ m3 at Mojo Asha and Adano schemes respectively. Outputs per unit command area in Birr/ha were 82501 and 96750 at Mojo Asha and Adano scheme respectively. Outputs per unit irrigated cropped area in Birr/ha were 55237 and 56437.5 at Mojo Asha and Adano schemes respectively. In case of water productivity Mojo Asha scheme was performing better than Adano scheme due to more productive use of irrigation water while land productivity was performing better at Adano than Mojo Asha scheme due to more intensive irrigation and better investment. Generally evaluation results of different indicators give information of performance level of the schemes that enables to transfer best practice to propose improvement measures.
UNBOUND AGGREGATEBASE COURSE CONSTRUCTION PRACTICES IN RELATIONTO PAVEMENTQUALITY IN HAWASSACITY
(Hawassa University, 2017-08-07) YOSEF ARAGAWLIDETE
Sub-standard quality unbound aggregate base course layers are prevalent in Hawassa city with the major cause often placed on inadequate construction practices. In this study, unbound aggregate base course construction practices in Hawassa city were investigated. The objective was to relate the potential effect of the practices on pavement quality. Data and information on unbound aggregate base course construction practices were collected through a questionnaire survey and observation of practices at a number of sites where base course layer construction works were on-going. In addition, laboratory and field tests on base course aggregates and base course layers respectively, were carried out on selected road construction projects. The results indicated that unbound aggregate base course construction practices in City do not exhibit existing advancements within the road paving industry and are partly to blame for the quality deficiencies associated with road pavements. Several benefits of current advances in the unbound aggregate base course construction such as the use of either a batch or a continuous type mixing plant, self-propelled paving machine (Paver), material transfer vehicles, stringent quality control and proper material selection, handling and storage at all stages were not appropriated. More importantly, the absence of strict follow-up and supervision for rejecting segregated and sub-standard pavement sections was the main factor worsening the problem. In principle, absence of strict supervision and adherence to the standards allows poor construction practices to prevail and provide no inspiration for contractors to pursue high construction quality because doing so entails extra cost and contractors do not suffer penalties for substandard works. Therefore, to improve the city’s road pavement construction practices and hence to improve the quality and durability of road pavements in Hawassa, strict follow-up and supervision for road construction, adherence to the standards, improving the capacity of contractors and adoption of innovative performance based contracting arrangements are necessary
PERFORMANCE EVALUATION OF FURROW IRRIGATION IN BELLES SUGAR DEVELOPMENT PROJECT SUGARCANE FARM LEVEL, ETHIOPIA
(Hawassa University, 2017-08-12) ADUGNAW ASEFAW NIGATU
Evaluation of farm irrigation system plays a fundamental role in improving surface irrigation and in providing information used to advice irrigators how to improve their system operation. Furrow irrigation is one of the common methods of applying water to sugarcane at Belles sugar development project Sugarcane Plantation. The plantation is facing problems with respect to irrigation water management. This study was initiated with the objectives of evaluating the performance of furrow irrigation system at a farm level. To evaluate the performance of furrow irrigation system, a soil laboratory and field measurements (field layout, furrow geometry, time of cutoff, discharge) are made. The soil infiltration parameters „a‟, „k‟ and „fo‟ for each irrigation event are determined based on a two point approximation to volume balance method that incorporated modified Kostiakove Lewis infiltration function. Statically comparison of models outcome found the Win SRFR simulated model values provides good fitter than the SIRMOD simulation values to the estimated values. The analyses of the performance of the furrow irrigation in terms of application efficiency (Ea), distribution efficiency (Du), storage efficiency tail water Ratio (TWR), and Deep Percolation (DP) were done and found to be, the average application efficiency 62.1%, 65.3% and 68.5% for SIRMOD, estimated and WinSRFR simulated values; distribution efficiency 90.4%, 92.4% and 95.5% for estimated, SIRMOD and WinSRFR simulated value; storage efficiency 24.1%, 26.4% and 32.8% for SIRMOD, WinSRFR simulated and estimated values; TWR 31.2%, 34.2% and 37.9% for WinSRFR, estimated and SIRMOD simulated values, respectively and deep percolation ratio for all estimation is null. From the sensitivity analysis furrow slopes are higher sensitive than other parameters on influencing the application efficiency. The effects of furrow lengths are highly influencing on TWR. The effect of discharge influence on the storage efficiency also high with compared to others whereas the time of cutoff found affect the distribution efficiency.
IMPACT OF URBANIZATION ON STORM WATER RUNOFF VOLUME AND QUALITY: THE CASE OF HAWASSA CITY, SOUTHERN ETHIOPIA
(Hawassa University, 2017-08-22) ASCHALEW SIDELIL SEBSIBE
Land use and land cover change results from various interactions between human being and environment. This study aims to identify and compare changes in land use and land cover occurred in the last 30 years in Hawassa city and its subsequent effect on runoff volume and quality. Information on land use and land cover changes that occurred from 1986 to 2016 in the study area was compared using remote sensing and geographic information system (GIS) with field verifications; Land-sat and spot satellite image were used to analyze the change. Three sets of remotely sensed Land-sat TM 1986, 2000 and 2016 were used to produce the LULC maps at different periods through a supervised classification of the satellite imageries using ERDAS IMAGINE and Arc GIS software. The Soil Conservation System (SCS) runoff volume calculation method that best fit for Ethiopia is used. Urban runoff water samples were gathered from the major runoff outfalls. The runoff sample collected manually using PVC scoop that received the entire flow and where then transferred to sampling bottles. The preparation of composite sample for one rainfall event is done by calibrating the sampling bottle with equal volume for three grab samples and preparing one event composite sample on site for that specific runoff event and sampling station. There was a significant expansion and encroachment of land use and land cover in Hawassa city between 1986 and 2016. In the study period the buildup area increased by 181.8% between 1986 and 2000. It also increased by 184.2% between 2000 and 2016. The total increment during the study period between 1986 and 2016 was about 700%. The second most changed LULC was vegetation cover that declined by 53.5% between 1986 and 2016, by 27.8% between 1986 and 2000 and finally by 37.2% between 2000 and 2016. Cultivated land was the least changed LULC. It declined by 12.2% from 1986 to 2016 but increment between 1986 and 2000 by 5.2% but decreased by 16.5% between 2000 and 2016. Bare land area also decreased by 50.8% from 1986 to 2016. The total storm water runoff depth was 35 mm and total volume was 5,833,460 m3. The storm water runoff depth indicates that 70.8% of the total rain fall changed to runoff water. During this time the contribution of the buildup area contribution was 3.8% and that of non-buildup area was 96.2% area wise. The runoff water quality laboratory results indicate that TN, TP, TSS, TDS, COD, BOD and Bacteria in the sample water were in excess of the level of permit discharge defined by the US environmental regulation
COMPARATIVE PERFORMANCE ASSESSMENT OF MOJO ASHA AND ADANO SMALL SCALE IRRIGATION SCHEMES IN EAST HARARGHE ZONE, OROMIA REGION
(Hawassa University, 2017-08-24) EBSA MUSTEFA HAKIM
This study attempts to assess and cross-compare the performance of two small-scale irrigation schemes found in Oromia regional state namely, Mojo Asha and Adano irrigation schemes using comparative indicators. After collection of the valuable data from various sources, data analysis techniques were implemented for evaluating their performance using selected performance indicators such as conveyance efficiency, Application efficiency, system efficiency, water productivity and land productivity. The results showed that the average conveyance efficiencies of the two schemes were 83.41 % and 76.78 % at Mojo Asha and Adano respectively. It was lower at Adano than Mojo Asha scheme due to poor water management and irrigation structures’ deterioration. The maximum value of application efficiency found in downstream field of Mojo Asha scheme were 65.43 % and the minimum value was found in the Adano scheme at upstream field 40.45 % due to much amount of water was applied to the field without considering water requirement. The results of water use performance also indicated that the ratio of annual relative water supply were1.09 and 1.19 at Mojo Aasha and Adano schemes respectively, and ratio of annual relative irrigation supply were 1.12 and 1.27 at Mojo Aasha and Adano schemes respectively. The result indicated that water distribution is not tightly related to crop water demand or applying more than the demand. From analysis of agricultural performance the output results showed that the outputs per unit irrigation supply were 8.62 and 7.92 Birr/m3 at Mojo Asha and Adano schemes respectively. Whereas output per unit irrigation delivered were 10.78 and 9.70 Birr/ m3 at Mojo Asha and Adano schemes respectively. Outputs per unit command area in Birr/ha were 82501 and 96750 at Mojo Asha and Adano scheme respectively. Outputs per unit irrigated cropped area in Birr/ha were 55237 and 56437.5 at Mojo Asha and Adano schemes respectively. In case of water productivity Mojo Asha scheme was performing better than Adano scheme due to more productive use of irrigation water while land productivity was performing better at Adano than Mojo Asha scheme due to more intensive irrigation and better investment. Generally evaluation results of different indicators give information of performance level of the schemes that enables to transfer best practice to propose improvement measures.
IMPACTS OF CLIMATE CHANGE ON RAINFED MAIZE PRODUCTION IN RIFT VALLEY LAKES BASINS OF ETHIOPIA; HAWASSA AS CASE STUDY
(Hawassa University, 2017-10-07) KINDE NEGESSA DISASA
Agriculture is mainstay of Ethiopian economy. Developing country like Ethiopia suffers from effects of climate change, due to their limited economic capability to build irrigation projects to reduce climate change impact on crop production. This study evaluates climate change impact on rainfed maize production in rift valley lakes basins of Ethiopia. First, outputs of 15 General Circulation Models (GCMs) under two emission scenarios (SRA1B and SRB1) are statistically downscaled by using LARS-WG software. Probability assessment of bounded range with known distributions is used to deal with the uncertainties of GCMs’ outputs. These GCMs outputs are weighted by considering the ability of each model to simulate historical records. The study result indicates that LARS-WG 5.5 model is more uncertain to simulate future mean rainfall than generating maximum and minimum mean temperatures hereby GCMs weight difference for rainfall mean is 0.83 whereas weight difference for minimum and maximum mean temperatures is 0.09. AquaCrop, version 4 developed by FAO that simulates the crop yield response to water deficit conditions, is employed to assess potential rainfed maize production in the study area with and without climate change. The study results indicate minimum and maximum temperatures absolute increase in the range of 0.34 0 C to 0.580 C, 0.940 C to 1.80 C and 1.420 C to 3.20 C and 0.320 C to 0.560 C, 0.910 C to 1.80 C and 1.340 C to 3.0350 C respectively in the near-term (2020s), mid-term (2055s) and long-term (2090s) under both emission scenarios. The expected percentage change of rainfall during these three time periods considering this GCMs weight difference into account ranges from -2.3 to 7%, 0.375 to 15.83% and 2.625 to 31.1%. Maize yields are expected to increase with the range of 3.63% to 7%, 5.39% to 14.08%, and 6.83% to 15.61%, during the same time periods. Unlike many studies in the world this study result show that maize yield increased in coming three time periods under both emission scenarios. Due to rainfall increase with temperature increase maize yield is expected to increase in future for this study area by using only rainfall. In conclusion, the results indicate that climate change will respond positively to climate change impact on maize yield production for this district if all field management, soil fertility and crop variety improved; but since there is rainfall variability among the seasons planting date should be scheduled well to combat water stress on crops
GIS BASED SOIL LOSS ESTIMATION USING USLE MODEL FOR SOIL CONSERVATION PLANNING: IN KARESA WATERSHED, LOMA WOREDA, SOUTH WEST ETHIO
(Hawassa University, 2017-10-10) BAGEGNEHU BEKELE MENGISTU
Soil erosion is the most challenging and continuous environmental problems resulting in both on-site and off-site effects in the world particularly in Ethiopia. Karesa watershed is one of the most erosion-prone watersheds which received little attention. Managing the on site erosion is to reduce the negative impacts of downstream water resources and requires an understanding of the rates of soil loss as well as identification of the major controlling factors that enhance or retard these processes. This study was conducted to estimate average annual soil loss rate using Geographic Information System and Universal Soil Loss Equation Model adapted to Ethiopian condition. The following datasets were obtained from different sources for estimating annual soil loss such as 15 years mean annual rainfall data for estimating Erosivity factor, digital soil map for estimating soil Erodibility factor, 30m x 30m resolution Digital Elevation Model for estimating slope length and slope steepness (LS) factor, Landsat6ETM+ images with 30mx30m resolution for detecting Vegetation cover and Conservation practice factor. Raster calculator was used to interactively multiply and produce annual soil loss. The result reveals that 42,413.72 ton per year soil loss from 9939 ha entire watershed and 4.27 tons per hectare per year average annual soil loss rate. The mean annual soil loss rate was classified in to four erosion severity classes as very less, less, moderate and High . The result also implies, two slope classes (0-15% and 15-30%) were categorized under very less to less soil loss (0-6.25 tons ha-1 yr-1 ) which accounts an area of 9383.07 ha (94.4%) of the watershed areas and representing 81.13% of the total soil loss. On the other hand, the watershed slope classes (>30%) fell under moderate to High soil loss (6.25-25 tons ha-1 yr-1 ) together covers 555.93ha (5.6%) of the watershed areas contributing 18.82% of the total soil loss mainly due to cultivation of marginal land,Intensive cultivation, poor vegetation cover during critical rainfall period. Moreover, about 2,184.93 ha of the watershed area was highly affected by erosion which contributes 18,182.25 tones yr-1 (42.87%) total soil loss and requires integrated soil and water conservation measures
STREAM FLOW RESPONSES TO CHANGES IN LAND USE/LAND COVER: THE CASE OF UPPER GIDABO CATCHEMENT, RIFT VALLEY LAKES BASIN, ETHIOPIA
(Hawassa University, 2017-10-11) TESFAHUN TADEWOS BATE
The study analyses the land cover change between the 1996, and 2011, and the effect these changes have had on stream flow on Upper Gidabo catchment. Within Upper Gidabo catchment land use is undergoing major changes due to pressures of human activities. Changes in land use have potentially large impacts on water resources by causing more surface runoff, decreased water retention capacity, loss of wetland and drying of river. In this study, both the Soil and Water Assessment Tool (SWAT) model and Spearman`s rank correlation statistical time series analysis for measured stream flow were applied to understand the stream flow variability and land use dynamics effect on stream flow of Upper Gidabo catchment. Land use maps of 1996, and 2011 were derived from satellite images and analyzed using ERDAS Imagine 2014 software. From the land cover change analysis results it was found that there has been a substantial decline of forest lands, shrub lands, wet lands and drastic expansion of agricultural land. The SWAT modeling results showed that an increase of stream flow by 21% comparing the two land use maps (1996 versus 2011). The analysis also revealed that flow during the wet months has increased by 9.53 % while the flow during the dry season decreased by 2.36 %. Furthermore the Spearman`s rank correlation test has been applied to detect the monotonic trend existence on the mean annual, seasonal, 1- and 7- days annual minimum and maximum flows. The Spearman`s rank correlation - test demonstrates that in the case of 1-day maximum flow, no significant trend is noticeable; however, the extreme low flows indicators (e.g.1day minimum,7 day minimum) and dry seasonal flows exhibited statistically significant decreasing trends. Generally, the combined results of the SWAT model and the statistical tests revealed that land use change has caused a significant increase on mean annual stream flow and decrease dry season flows of the studied watershed during the period. The identified result is important to inform optimal water resource management and to plan and manage water resources development within the watershed in a sustainable manner
W YTIVITCUDORP DNA DLEIY ER S NOP SE FO NOINO DNU RE LLUF DNA ICIFED T NOITAGIRRI NI W RETA S ECRAC AERA , M OKERA ,ADEROW ET IPOIH A
(Hawassa University, 2017-10-11) KE ARD LA AW BELA UH SSEN
F retaw si acs r ec in ynam strap fo ht e dlrow dna nimoceb g a labolg a .adneg erutlucirgA si eht tsegral gnoma s tce o sr hcihw era snoc u gnim eguh hserf retaw . ehT sevitcejbo fo siht duts y erew ot evorpmi larutlucirga retaw ytivitcudorp a dn etagitsevni eht dleiy esnopser fo noino porc ot retaw .ticifed ehT dohtem deyolpme pmocne a sess dleif tnemirepxe ni dezimodnar telpmoc e kcolb ngised ( BCR D) htiw nevele stnemtaert na d eerht .snoitacilper ehT stnemtaert :erew lluf noitagirri ( %0 ticifed sa lortnoc ), %52 fo CWR ticifed tuohguorht org wing %05,nosaes fo CW R ticifed tuohguorht worg i gn ,nosaes dna eno p doire ticifed stnemtaert (25% dna %05 fo CW R ticifed ta in laiti , ,tnempoleved dim dna etal s egat s). ehT xe p tnemire saw deirrac tuo ta okeram aderow nrehtuos .aipoihtE stluseR dewohs taht secnereffid ni rri i tag noi retaw tnuoma yltnacifingis tceffa yponac ,revoc blub dleiy dna a evob dnuorg ssamoib fo .noino ehT umixam m elbatekram dleiy saw ac deriuq morf ylluf detagirri tnemtaert (T1) w cih h si 39.91 ah/t dna ht e muminim elbatekram yi dle saw deniatbo morf 3T ( %05 of CWR cifed it guorht tuoh org w ni g osaes n) hcihw si 01 13. t/ .ah 01T ( %05 fo C WR de ticif ta im d egats ) wohs ed eht muminim sevrah t xedni ( 6.0 8) na d 4T dna 7T ( %52 fo CWR ticifed ta ni laiti dna etal segats itcepser ev yl ) ewohs d eht mumixam .xedni hT e tsewol IH i detacidn taht retaw ticifed ta dim ts ega sesuac hgih leiy d .noitcuder ehT ma umix m porc retaw dorp u ytivitc ( 9.4 8 m/gk 3 ) saw bo s vre ed ta 3T ( 05 % fo CW R ticifed tuohguorht worg i gn osaes n) dna eht muminim ( 22.3 m/gk 3 ) saw o devresb ta 01T (50% o f CWR ticifed ta dim ts age). ehT tsegral retaw gnivas htiw s tnacifingi dleiy noitcuder aw s deniatbo ta 3T .Y dlei esnopser rotcaf ( yk ) acidni t de taht noino saw evitisnes dleiy( uder ced) rof retaw sserts ta tnempoleved dna dim htworg st .sega %05 fo CWR d ticife ta eno doirep serts s stnemtaert dewohs k 1>y , hcihw setacidni eht s ne s ytiviti fo eht o noin porc f ro hgih retaw sserts . ehT cimonoce sisylana i detacidn taht eht ixam m mu lanigram etar fo nruter saw deniatbo ta T 11 (50% fo CWR d ticife ta eht etal gats e) htiw a ten emocni fo 077,801 ah/rrib dna a lanigram tar e fo nruter 9.2765 .% ehT r ,erofe 11T ( %05 fo CWR ticifed ta etal s egat ) is yllacimonoce lbaiv e metsys fo noino noitcudorp htiw ingis f tnaci etaw r gnivas dna fi sremraf ta siht latnemirepxe etis pa e