Irrigation and Drainage Engineering

Permanent URI for this collectionhttps://etd.hu.edu.et/handle/123456789/70

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Start date: 2020End date: 2023

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    PRACTICE OF CONSTRUCTION SCHEDULING AND ITS IMPACT ON DELAY CLAIM ANALYSIS
    (Hawassa University, 2022-10-23) SADAT AHMED ABDELA
    Construction schedules should sufficiently and accurately provide the necessary information to measure effect of a delay event on: succeeding activities, project duration and project cost. However, it was concluded that programs being submitted by contractors in the Ethiopian context don't assist to analyze delays. Performance of delay claims analysis in Ethiopian context is usually very low in terms of accuracy because analysis is little based on reliable and sufficient schedule information. The objective of this thesis was to evaluate practice and challenges of construction scheduling in view of delay analysis in Ethiopia, the impact on delay claim analysis and propose a scheduling framework to improve performance of DCA. In collecting data, survey questionnaire was delivered to purposively selected construction professionals and 155 complete responses were collected. The data was checked for construct validity, content validity and reliability. Mean scores of factors were calculated and one sample T-tests were performed to evaluate relative significance. Multiple regression analysis was conducted to predict impact of the scheduling practice factors and documentation of as￾built records on performance of delay claim analysis. Results of the study showed that the construction scheduling practice in Ethiopia is below satisfactory in providing accurate and sufficient information for delay analysis in all dimensions studied. Low Responsiveness of Contractors’ Top management to Schedules (1), Lack of Technical knowledge and skill of Scheduling (2), Absence of National Scheduling Standards (3) and Task of iteration in a resource constrained environment (4) were identified challenge factors of construction scheduling in Ethiopia. Task of iteration in a resource constrained environment was found the most challenging factor. Reliability of Schedule (1), Accuracy and Timely Communication of Update Schedules (2), Documentation of Old Schedules and the Schedule 1 2 basis (3) and Conciseness of Schedule (4) were identified as scheduling practice factors impacting delay claim analysis. Results of regression analysis showed that Documentation of as built records has the most prediction of the impact on delay analysis performance whereas Conciseness of Schedule has the least prediction. The regression model was significant with F (5,149) = 20.145, P < 0.001. A case study that confirmed results of the quantitative analysis was also conducted. Finally, a scheduling framework to improve performance of delay claim analysis was developed. The developed framework indicates roles of stakeholders in mitigating the impacting factors. The findings of this study are helpful to improve performance of DCA and the scheduling practice because it revealed the status of the practice, identified challenges to be tackled and provided a framework guide for improvement
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    EFFECT OF DEFICIT IRRIGATION LEVELS ON YIELD AND YIELD COMPONENTS OF SESAME (Sesamum indicum L.) IN BENA TSEMAY WOREDA, SOUTH OMO ZONE, ETHIOPIA
    (Hawassa University, 2022-10-27) MEDHIN MADEBO MADA
    Scarcity of water is one of the major constraints for the development of agriculture in arid and semi-arid regions. Hence, the effective use of available water by deficit irrigation is an alternative means to alleviate the problem and optimize the water productivity of crop in the region. The objective of this study was to determine the effect of deficit irrigation levels applied on yield, yield components and water productivity of sesame (Sesamum indicum L.). The field experiment was carried out at Bena Tsemay Woreda, Southern Ethiopia. The experiment was laid out in randomized complete block design with six irrigation treatments and three replications. The treatments were five water deficit irrigation levels (85%ETc, 75%ETc, 65%ETc, 55%ETc and 45%ETc) and full (100%ETc) as a control treatment. The result of analysis of variance showed that the different deficit irrigation levels applied had statistically significant (p < 0.01) effect on yield and yield component of sesame. Significant delay in flowering and maturity was observed as the water deficit level increased. The highest plant height, number of branch per plant, number of capsules per plant, number of seed per capsule, 1000-seed weight, aboveground biomass, harvest index and straw yield were observed under control treatment (100%ETc), while the lowest observed in 45%ETc treatment respectively. The maximum grain yield (2164.56 kg/ha) was observed under control (100%ETc), while the minimum (1377.37 kg/ha) was obtained from 45%ETc treatment level. From the mean result of grain yield it was observed that control treatment (100%ETc) significantly different from all treatments except treatment under 85%ETc. The highest water productivity (0.55kg/m3 ) was observed under 45%ETc, while the lowest (0.39 kg/m3 ) was at control treatment. From the result of study it was observed that the obtained yield response factor (Ky) was less than unity (Ky < 1), this indicates that sesame is tolerant to water stress. From the result of study it was observed that deficit irrigation under 75%ETc resulted in significant water saving and improved water productivity with insignificant yield reduction; therefore, sesame could be irrigated at 75%ETc in region with limited water resource condition
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    PERFORMANCE EVALUATION OF FIELD WATER APPLICATION ON FURROW IRRIGATION AT WONJI SHOA SUGAR ESTATE, ETHIOPIA
    (Hawassa University, 2021-10-22) TSIGE MOHAMMED AHMED
    Furrow irrigation is dominantly used method of surface irrigation in the large sugar cane irrigation projects in Ethiopia. This research was conducted to evaluate the performance of furrow irrigation with SIRMOD software by two point method and evaluate current performance of furrow irrigation system, identify the performance gaps and recommend means of performance improvement at Wonji Shoa Irrigation Estate. Three fields were selected according to soil type, furrow length and workability for measurement with field code 15, 52,108 which had furrow length of 64 m, 48 m and 32 m which was practice in the sugar estate. Different performance indicators were used to evaluate performance of furrow irrigation they were application efficiency, storage efficiency, application uniformity and deep percolation ratio. The estimated and simulation result obtained from the average application efficiency of the three selected fields (15, 52, and 108) were 74.42%, 41.19% and 64.12% and 74.39%, 50.20% and 75.18% respectively. The storage efficiency values for three selected fields were 100% for estimation and 99.11%, 99.67% and 99.65% for simulation respectively. The estimation and simulation average distribution uniformity of the three selected fields were 91.86%,90.78% and 89.86% and 92.44%,91.38% and 93.26% respectively and the deep percolation ratio for estimated and simulation were 25.35%,58.81% and 35.88% and 25.35%, 49.48% and 24.5 respectively . From the selected fields, filed 15 and 108 had better application efficiency with furrow length 64 and 32 respectively than the filed 52 with furrow length 48 m and the field 52 had low application efficiency and high deep percolation ratio. The result obtained from sensitivity analysis; discharge, cutoff time and length of furrow were highly sensitive to application efficiency and deep percolation ratio, whereas the slope of furrow had no effect on performance indicator in this study. The amount of water applied during irrigation event were more than the irrigation water required which indicates that large amount of water was being wasted due to poor irrigation water management practice. From the result of this study, it can be concluded that there were over irrigation problems
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    PERFORMANCE EVALUATION OF WAQEMIYA TIYO AND AWASH MELKASA IRRIGATION SCHEMES IN EAST SHEWA ZONE, ETHIOPIA
    (Hawassa University, 2023-10-15) ALEMIYE DEGEFA TOLA
    Performance evaluation of irrigation schemes plays a fundamental role in improving irrigation system of scheme by identifying performance gaps that help to provide appropriate improvement options. Therefore, the aim of this study was to evaluate and compare the performance of Waqemiya Tiyo and Awash Melkasa community managed small-scale irrigation schemes located at Adama District, Oromia, Ethiopia using internal and external performance indicators. For this purpose, primary and secondary data were collected from the schemes and for field data measurements three farmers’ fields were selected at the head, middle and tail-end of each scheme. Schemes were evaluated by their own merits with the help of internal performance indicators. Thus, the results of analyses revealed that conveyance, application, storage, overall scheme efficiency and distribution uniformity were 49.0, 56.2, 48.8, 27.5 and 88.2% and at Waqemiya Tiyo whereas, 45.6 53.3, 44.1, 24.3 and 85.8% Awash Melkasa schemes respectively. Then comparison was made using external performance indicators such as water supply, water delivery capacity, outputs and physical indicators. The results obtained revealed that the values of relative water supply and irrigation supply were 0.59 and 0.57 for Waqemiya Tiyo scheme, whereas 0.65 and 0.64 for the Awash Melkasa scheme respectively. Water delivery capacities of Waqemiya Tiyo and Awash Melkasa schemes were 0.60 and 0.37 respectively. The values of output per unit irrigated area were 3962.6 and 2187.3 US$/ha, and similarly the output per unit command area was 4507.4and 2479.US$/ha for two schemes respectively. The output per unit irrigation supply and water consumed were 0.79,0.45US$/m 3 and 0.91,0.57US$/m 3 for two schemes respectively. Likewise, Physical indicators such as irrigation ratio and sustainability of the irrigated area revealed that 1.14, 1.07 and1.11, 1.04 for two schemes, respectively. Based on the results obtained, Awash Melkasa scheme was better in terms of relative water supply and irrigation supply. However, Waqemiya Tiyo scheme had significantly better land and water productivity than Awash Melkasa scheme due to used high value crops, agricultural inputs and removal of grass cover and sedimentation from canal systems. As a result, Waqemiya Tiyo scheme was better performing than Awash Melkasa scheme therefore, practices high value crops, sharing their experience with one another to achieve good performance of the schemes.
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    EFFECT OF DEFICIT IRRIGATION ON WATER PRODUCTIVITY AND YIELD OF COMMON BEAN (PHASEOLUS VULGARIS L.) AT MELKASSA, CENTERAL RIFT VALLEY, ETHIOPIA
    (Hawassa University, 2020-10-12) ABERA TESFAYE TEFERA
    The experiment was conducted at Melkassa Agricultural Research Center during off season under semi-arid climatic condition where moisture stress is higher. The study was under taken to evaluate effect of deficit irrigation on water productivity and yield of common bean (Phaseolus vulgaris L.).The experiment was split plot design with three common bean varieties as main plots and four deficit irrigation levels as sub plots all of which replicated three times. Four deficit irrigation levels 100%ETc, 85%ETc, 70%ETc, 55%ETc and three varieties SER-119, Bio fortified small seed-5, Awash-2 were used for treatment combination. The combined result indicates that there was a significant variation among treatments for yield, above ground biomass and water productivity. All common bean varieties were significantly affected under deficit irrigation levels. Consequently, highest yield (3.4 ton/ha) was obtained from irrigating 100%ETc followed by (3.2 ton/ha) with 85%ETc less yield reduction. In contrast the intermediate (2.8 ton/ha) and smallest yield (2.4 ton/ha) was obtained from irrigating 70ETc and 55%ETc.Water productivity was ranged from (0.83 kg/m3 ) at full irrigation to (1.33 kg/m3 ) at higher deficit irrigation. Based on obtained yield and water productivity, under a limited water supply situation where the goal was to gain highest possible yield of common bean and water productivity utilizing application of water from 70%ETC to 85%ETC at each irrigation event offers opportunities for water saving with yield reduction which was compensated by irrigating other area by saved water. The result of economic analysis shown that the highest net benefit obtained from irrigating full 100%ETc of the three common bean varieties. Based on obtained data the MRR was greater than 50% irrigating common bean with deficit irrigation 85%, 70% and 55% is economically feasible depending on accessibility of water
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    EFFECT OF DEFICIT IRRIGATION LEVELS ON YIELD AND YIELD COMPONENTS OF SESAME (Sesamum indicum L.) IN BENA TSEMAY WOREDA, SOUTH OMO ZONE, ETHIOPIA
    (Hawassa University, 2022-08-11) MEDHIN MADEBO MADA
    Scarcity of water is one of the major constraints for the development of agriculture in arid and semi-arid regions. Hence, the effective use of available water by deficit irrigation is an alternative means to alleviate the problem and optimize the water productivity of crop in the region. The objective of this study was to determine the effect of deficit irrigation levels applied on yield, yield components and water productivity of sesame (Sesamum indicum L.). The field experiment was carried out at Bena Tsemay Woreda, Southern Ethiopia. The experiment was laid out in randomized complete block design with six irrigation treatments and three replications. The treatments were five water deficit irrigation levels (85%ETc, 75%ETc, 65%ETc, 55%ETc and 45%ETc) and full (100%ETc) as a control treatment. The result of analysis of variance showed that the different deficit irrigation levels applied had statistically significant (p < 0.01) effect on yield and yield component of sesame. Significant delay in flowering and maturity was observed as the water deficit level increased. The highest plant height, number of branch per plant, number of capsules per plant, number of seed per capsule, 1000-seed weight, aboveground biomass, harvest index and straw yield were observed under control treatment (100%ETc), while the lowest observed in 45%ETc treatment respectively. The maximum grain yield (2164.56 kg/ha) was observed under control (100%ETc), while the minimum (1377.37 kg/ha) was obtained from 45%ETc treatment level. From the mean result of grain yield it was observed that control treatment (100%ETc) significantly different from all treatments except treatment under 85%ETc. The highest water productivity (0.55kg/m3 ) was observed under 45%ETc, while the lowest (0.39 kg/m3 ) was at control treatment. From the result of study it was observed that the obtained yield response factor (Ky) was less than unity (Ky < 1), this indicates that sesame is tolerant to water stress. From the result of study it was observed that deficit irrigation under 75%ETc resulted in significant water saving and improved water productivity with insignificant yield reduction; therefore, sesame could be irrigated at 75%ETc in region with limited water resource condition
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    PRACTICE OF CONSTRUCTION SCHEDULING AND ITS IMPACT ON DELAY CLAIM ANALYSIS
    (Hawassa University, 2022-08-08) SADAT AHMED ABDELA
    Construction schedules should sufficiently and accurately provide the necessary information to measure effect of a delay event on: succeeding activities, project duration and project cost. However, it was concluded that programs being submitted by contractors in the Ethiopian context don't assist to analyze delays. Performance of delay claims analysis in Ethiopian context is usually very low in terms of accuracy because analysis is little based on reliable and sufficient schedule information. The objective of this thesis was to evaluate practice and challenges of construction scheduling in view of delay analysis in Ethiopia, the impact on delay claim analysis and propose a scheduling framework to improve performance of DCA. In collecting data, survey questionnaire was delivered to purposively selected construction professionals and 155 complete responses were collected. The data was checked for construct validity, content validity and reliability. Mean scores of factors were calculated and one sample T-tests were performed to evaluate relative significance. Multiple regression analysis was conducted to predict impact of the scheduling practice factors and documentation of as￾built records on performance of delay claim analysis. Results of the study showed that the construction scheduling practice in Ethiopia is below satisfactory in providing accurate and sufficient information for delay analysis in all dimensions studied. Low Responsiveness of Contractors’ Top management to Schedules (1), Lack of Technical knowledge and skill of Scheduling (2), Absence of National Scheduling Standards (3) and Task of iteration in a resource constrained environment (4) were identified challenge factors of construction scheduling in Ethiopia. Task of iteration in a resource constrained environment was found the most challenging factor. Reliability of Schedule (1), Accuracy and Timely Communication of Update Schedules (2), Documentation of Old Schedules and the Schedule 1 2 basis (3) and Conciseness of Schedule (4) were identified as scheduling practice factors impacting delay claim analysis. Results of regression analysis showed that Documentation of as built records has the most prediction of the impact on delay analysis performance whereas Conciseness of Schedule has the least prediction. The regression model was significant with F (5,149) = 20.145, P < 0.001. A case study that confirmed results of the quantitative analysis was also conducted. Finally, a scheduling framework to improve performance of delay claim analysis was developed. The developed framework indicates roles of stakeholders in mitigating the impacting factors. The findings of this study are helpful to improve performance of DCA and the scheduling practice because it revealed the status of the practice, identified challenges to be tackled and provided a framework guide for improvement.
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