Water Resource

Permanent URI for this collectionhttps://etd.hu.edu.et/handle/123456789/71

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Start date: 2020End date: 2021

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Now showing 1 - 10 of 46
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    EVALUATING THE PERFORMANCE OF HEC-HMS AND SWAT HYDROLOGICAL MODELS IN SIMULATING THE RAINFALL RUNOFF PROCESS FOR DATA SCARCE REGION OF ETHIOPIAN RIFT VALLEY LAKE BASIN
    (Hawassa University, 2020-10-23) MOHAMMEDRESHID ABDALA ALIYE
    Several physically-based and distributed watershed models have been developed to model the hydrology of the watershed. For a specific watershed, selecting the most suitable hydrological model is necessary to obtain good simulated results. In this study, two hydrologic models, Soil and Water Assessment Tool (SWAT) and Hydrological Engineering Centre–Hydrologic Modeling System (HEC-HMS), were applied to simulate streamflow in the Katar river basin, Ethiopia. The performances of these two models were compared to select the right model for the study basin. Both models were calibrated and validated with streamflow data of 11 years (1990- 2000) and 7years (2001-2007) respectively. Nash-Sutcliffe Error (NSE) and Coefficient of Determination (R2 ) were used to evaluate the efficiency of the models. The results of calibration and validation indicated that, for river basin Katar, both models could simulate fairly well the streamflow. SWAT gave the model performance with the R2 > 0.78 and NSE > 0.67; and the HEC-HMS model provided the model performance with the R2 > 0.87 and NSE > 0.73. Hence, the simulated streamflow given by the HEC-HMS model is more satisfactory than that provided by the SWAT model
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    RESPONSE OF WHEAT (Triticum Aestivum L.) YIELD AND YIELD COMPONENTS UNDER DIFFERENT MOISTURE STRESS LEVELS AT GEWANE WOREDA, AFAR REGION, ETHIOPIA
    (Hawassa University, 2021-08-19) ZIYAD RUBE HAMID
    Enhancing water productivity of irrigated crops through Agricultural water management practices is a vital option in water scarce areas. Field experiment was conducted at demonstration site of Gewane Agricultural Technical Vocational and Educational Training College located in Gewane woreda, Afar region, Ethiopia. The objective of this research was aimed to identify optimum moisture stress levels for wheat under moisture stress area of Gewane woreda. Ten deficit irrigation levels namely (45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 %ETc) and the control (100%ETc) irrigation water application were used in whole growing season of wheat (Triticum aestivum L.). Adopted wheat variety Fentale -2 was used as testing crop and laid out in randomized complete block design with three replications. The daily climatic parameters used to estimate ETo were collected from Gewane meteorological station. Daily crop water requirement (ETc) was estimated by multiplying reference evapotranspiration with crop coefficient. Yield and yield components were collected and analyzed using SAS 9.0 statistical software. The analysis of variance showed that, the reduction of water application (moisture stress levels) had a highly significant (p<0.01) effect on growth parameters, yield and yield components except on the number of tillers per square meter and harvesting index as compared to the full irrigation (100%ETc). The result also showed that, the grain yield reduced as the stress levels increased, whereas water use efficiency was increased as the stress levels increased. The highest grain yield of 4472.2 kg/ha was obtained from full irrigation( 100%ETc) which had no significant difference with irrigation water application up to 70%ETc. Whereas the lowest grain yield of 3475.7 kg/ha was recorded from 45%ETc. In terms of water use efficiency, the highest and lowest water use efficiency of 1.32 and 0.82 kg/m3 was obtained from 45 and 100%ETc respectively. Therefore, wheat could be irrigated at 70%ETc to improve water use efficiency without a significant grain yield reduction. Moreover, it could be irrigated at 45%ETc in area where water use efficiency is top priority with compromise of grain yield reduction by 22.28% as result of saved water to irrigate other crops
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    GIS-BASED SURFACE IRRIGATION POTENTIAL ASSESSMENT: A CASE STUDY IN MUGA WATERSHED EAST GOJAM ZONE, AMHARA REGION, ETHIOPIA
    (Hawassa University, 2021-10-22) ZELALEM ABEZA
    Assessing available water and land for surface irrigation is important for planning their use. The high dependency on rain-fed farming and erratic rainfall require alternative ways of improving agricultural production. The alternative to improve is through development of small scale irrigation schemes by assessing the available suitable land and water resources in sub-basin level. The objective of this study was assessing the land and water resources potential of Muga watershed in East Gojjam Zone for surface irrigation development using Geographic Information System. Identification of suitable land, estimation of available river flow, and determination of irrigation water requirement were the main steps that were followed. The land irrigation suitability factors considered were: slope, soil, land use/land cover, and river proximity. Estimation of river flow in the six manually added outlets was conducted by simulation after calibration and validation were carried out with the observed flow of gauged river using Soil and water assessment tool. The commonly cultivated crops in the area maize, onion and potato were selected, and the irrigation water requirements of these crops were determined using the CROPWAT8.0 model. Comparison between gross irrigation water requirement of the selected crops for the identified suitable land with simulated river flow at the area of the selected site was carried out. Overall, the weighted overlay analysis of these factors gave a suitable land among river sub-basin as G/muga 560ha, E/muga 3057ha, Bora 670ha, Gibstawit 404ha, and Genet 241ha. Mean monthly flow of 11.4m3 /s were determined at the watershed. A total of 3443ha (5.1%) was found to be potentially suitable for the development of surface irrigation project from a total watershed area of 67535ha. In conclusion, the irrigation potential of the area could be increased either by harvesting rainwater or using groundwater.
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    PERFORMANCE EVALUATION OF STORMWATER DRAINAGE SYSTEM OF BEDELE TOWN
    (Hawassa University, 2020-10-24) YEROSAN KEBEDE AYANA
    Various factors can degrade the drainage system and reduces its performance. As the role of drainage infrastructure is very high in preventing urban floods, their performance should be monitored and quantified. This study aimed to assess the performance of stormwater drainage systems in Bedele Town. Primary and secondary data were used in this study. The catchment that contributes runoff was delineated using ArcGIS 10.4 software. The Stormwater Management Model (SWMM 5.1) was used to simulate the peak flow rate and water level in the drainage canals by considering the current land use. The intensity duration frequency (IDF) curve was developed by using the Log-Pearson Type III. The peak runoff for 10-year and 25-year return periods was estimated by using the Rational Method. The condition of the existing drainage system was assessed and poor solid waste management, lack of well-connected drainage lines, poor liquid waste disposal, and the existence of fully uncovered areas in the town with drainage structures were identified to be the drainage problem of the Town. From the total area of Bedele Town, 41.1% is uncovered with the drainage systems. The total peak runoff generated from this study area is 15.59 m3/s and the average velocity was 2.5m/s for a 10-year return period. The result from the Rational method as well as SWMM 5.1 shows there is an overflow problem in this study due to the presence of drainage canals with insufficient capacity to carry the runoff generated from this catchment. For a sustainable drainage system, the appropriate use of hydrological analysis, hydraulic design, and stream morphological study should be implemented before carrying out the construction of drainage structures for they were not considered during the construction of the drainage system of the Town. Regular maintenance and frequent clearance of drainage lines, proper integration between roads and drainage structures, provision of additional drainage canals, and improved stormwater management were recommended to solve the stormwater drainage problem of the Tow
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    ASSESSING FARM WATER MANAGEMENT AND INFRASTRUCTURAL PERFORMANCE OF KOGA IRRIGATION SCHEME; IN THE CASE OF INGUTI UNITE
    (Hawassa University, 2020-11-20) WUBLIKER NEGESE YIHUNE
    Irrigation scheme performance was assessed to evaluate the field water managements and its infrastructural performance .The principal objective of this study was to evaluate field water management and infrastructural performance of Koga irrigation scheme specifically Inguti unit using selected internal performance indicators. Moreover, an institutional support service was evaluated to understand how the scheme is being administered. Field data such as discharge, soil moisture content, and soil physical properties and infrastructures performance were collected. Field surveys and group discussions among the farmers/beneficiaries and Water User Associations (WUA) was also conducted to evaluated existing situation of the support service in the scheme and its performance of WUA. From house hold survey 493 users55 beneficiaries were selected by stratified random sampling. Field surveys and group discussions among the farmers/beneficiaries and Water User Associations (WUA) was also conducted to evaluated existing situation of the support service in the scheme and its performance of WUA. From house hold survey 493 users55 beneficiaries were selected by stratified random sampling. Secondary data such as crop data, climate data and design documents were collected from National Meteorological agency and Koga Irrigation Project office. CROPWAT 8.0 model, GIS and Microsoft office (excel and word) were used for data analysis and documentation in this thesis. Average conveyance efficiency values ranged from 81 to 86.5% for lined (secondary and tertiary canals) and about 64% for unlined tertiary canals. The maximum water loss observed was 0.19 and 0.21l/s/m on lined (secondary and tertiary) canals respectively. And also the maximum water loss observed in unlined tertiary canals was 0.26l/s/m. The average field storage efficiency was found to be 78.9 % and the average field water application efficiency was 53.5%. Average values of the scheme water level ratio, cropped area ratio and infrastructural effectiveness was 85.8%, 94% and 96.2% respectively. The performance of the irrigation scheme was weak due to poor field water managements as indicated above. This might be attributed due to a number of factors observed at field such as illegal water abstraction, unequal distribution of irrigation water, sedimentation of canals and inadequate operation and canal maintenance. Field survey indicates sedimentation, cracking and weeds problems in the lined canals. The overall efficiency of scheme in the Inguti unit was found to be 46.3%. This implies organizational set up and legal enforcement of bylaws and institutional support service was weak to fully maintained and managed irrigation water in the fields
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    THE WATER SUPPLY AND DEMAND ANALYSIS IN THE CASE OF BONOSHA TOWN SHASHOGO WOREDA HADIYA ZONE SNNPR
    (Hawassa University, 2021-12-24) TIMOTIWOS TUFA
    The main objectives of this study was to analyze water supply and demand of Bonosha town water distribution system. The supply part was assessed by collecting data of water source yield in town, which is located north of the town. The town has single water source, which has 4 l/s yield. To evaluate the demand of the town population, number of schools, churches, mosques, health institution, government office and restaurants are assessed. To analyze the existing water distribution system, the EPANET model was developed.The model used to identify the level of velocity through pipe and the zone of high and low pressure. The result of research shows that the non-domestic and domestic water supply coverage of the Bonosha town is 30%. This implies that there is high gap between demand and supply. In addition, from three years obtain data of production and consumption the average loss become 20.18%. Furthermore, the model analysis result shows that there significant problem of pressure and velocity in the system. The majority of junctions have negative pressure. This implies that user are not getting sufficient water. Moreover, the problem of Bonosha town water is insufficient yield, design problem and increasing population. The pump failure is one of major challenge in town
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    GIS BASED GROUNDWATER POTENTIAL MAPPING AND RECHARGE 1 ESTIMATION: A CASE STUDY IN MELKAODA WATERSHED RIFT VALLEY LAKES 2 BASIN, OROMIA, ETHIOPIA
    (Hawassa University, 2021-10-24) ADEM BUTA DEKEBO
    The groundwater potential zones of the Melkaoda Watershed were demarcated with the help of remote sensing and Geographic Information System (GIS) techniques. The parameters that were considered for identifying the groundwater potential zone like geology, slope, drainage density, geomorphic units, and lineament density were generated from satellite data and they were then integrated with weighted overlay in ArcGIS. Suitable ranks were assigned for each category of these parameters and weight factors were decided for them based on their capability to store groundwater using AHP approach and then the groundwater potential zones were classified into four categories as very low, low, high & very high. In addition, the groundwater recharge was estimated with the help of the WetSpass model using water balance approach. The parameters considered for this case generally included three types: hydro-meteorological (rainfall, temperature, wind speed, PET, and GWD), bio-physical (soil, landuse, topography, and slope), and attribute lookup (soil lookup, landuse lookup, and rain day lookup) tables. All the hydro-meteorological parameters were interpolated in ArcGIS for grid map preparation of each parameter and the prepared grid map was converted to ASCII file format for the effective model run. The model performance was checked through calibration and the obtained groundwater recharge result ranges 0.45 to 65.5 mm/year with the mean value of 32.87 mm/years and 3.4% contributed to groundwater as recharge. finally, the changes in groundwater recharge between two simulation period was stated again with help of WetSpass model using the LULC images of 1989 and 2018 to quantify the impacts of the LULCC. The parameters used for this analysis were the same as those used for groundwater recharge estimation except for the satellite image of 1989 and the LULCC analysis depicted that there was the expansion of built-up land and agricultural land. Agricultural land and built-up land were increased by 0.046, 2.56 rate per a year from 1989 to 2018 respectively. This paper finalized that there was access to the groundwater potential in the Melkaoda Watershed and this could overcome the water scarcity challenging the community in and around the area. The recharge which has been the main source of groundwater is decreasing from time to time as the result of this paper is indicating. Thus, to get sustainable groundwater potential, the recharge has to be well treated by increasing groundwater recharge
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    STORM WATER DRAINAGE SYSTEM ANALYSIS OF HAWASSA CITY, ETHIOPIA
    (Hawassa University, 2021-10-24) GIRMA YANE RIKIBA
    Intense rainfall and urbanization are the main factors that affect the storm drainage system. In addition to rainfall intensity and impermeable layers, system blockage by solid wastes is the common problem in Hawassa city. The study achieved the objective of storm water drainage system analysis of Hawassa city. To analyze the level of the problem models like Arc GIS10.2, Google earth Pro, Generalized Extreme Value distribution and rational method are used to delineate the drainage system, classify of the sub watershed, simulate the design rainfall depth and runoff volume estimation respectively. The peak discharge generated in 2002 was 54.45m3 /s. Due to both factors the peak discharge generated counts 102.80m3 /s in 2019. Following the drainage system networking capacity of 13drains (59.09%) exceeded by design discharge, 20(90.91%) by 25 years discharge and 21(95.45%) drains capacity exceeded by 100 years discharge that contributes to pedestrian mobility interruption, traffic congestion , chronic distress of asphalt road and environmental health problem due to over flooding. Communication between professionals responsible for storm water drainage system, collaboration of institutions such as water supply, sewerage and sanitation, solid waste management and infrastructure department should be maintained. SUDs measures such as sizing drain and retention pond strategies to cope with intense rainfall and urbanization impact on storm drainage system and environment were recommended.
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    ASSESSMENT OF THE WATER DISTRIBUTION NETWORK PERFORMANCE OF DURAME TOWN WATER SUPPLY SYSTEM
    (Hawassa University, 2021-12-21) TESFAHUN MATHEWOS
    The research work was focused on the assessment of water supply distribution network performance of Durame Town, which is the Zonal Town of Kembata Tembaro Zone in Southern Nation Nationality People Regional State of Ethiopia. The main objective of this thesis was to assess Durame Town water supply system by analyzing water demand and supply, water distribution network, water losses and leakage management of the pipe system in the service. To examine the hydraulic performance of the water distribution network system, water GEMS modeling was adopted. The model was used to identify the zone of high pressure and low pressure in junctions and the level of velocity through pipe system. The model run was performed for average velocity, peak demand and low demand to analyze the system model. Furthermore the model analysis result shows different problems of aged pipes, oversized and undersized pipes, high pressure during night flow and low pressure during day flow. As per the analyzed results; the current maximum water demand in Durame town is estimated at 6392.304m 3 /day, while small reservoirs capacity and low pump efficiency were observed in the town water distribution networks and the maximum pressure occurred at night demand is 85m which is above the recommended value. Further, the analyzed water losses result in Durame Town indicates that about 32.58% of production is Non-Revenue Water. Thereby, apparent losses cover 1.76% of total loss and 30.81% were physical losses. Accordingly, for the case of Durame Town apparent losses are less significant, however physical losses contributed unconsidered volume of lost. In general, high demand of water, small capacities of existing infrastructures and large volume of water loss lead to intermittent water distribution in Durame Town. Therefore, it is significant to rehabilitate and improve the , water demand and supply system and providing more attention for the causes of water losses, and leakage management of the Town.
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    ANALYSIS OF HYDRUALIC PERFOMANCE OF ALETA WONDO TOWN WATER SUPPLY DISTRIBUTION SYSTEM
    (Hawassa University, 2021-10-25) TEKA FETOSA JILO
    In many of the developing countries, the hydraulic and physical performance of water distribution network is inadequate to meet consumers’ demands that encounter significant losses in the system. Aleta-Wondo has been experiencing frequent and regular disruption of water supplies for days to a week. This study was conducted in Aleta-Wondo Town to analyze the existing water supply distribution system of the Town. Both primary and secondary data sources were used in this study. Primary data were collected though face-to-face interview with Aleta Wondo Water Supply Office experts, field observation. For secondary data collection, document review was used to collect valuable information. To analyze the data which is collected from different sources, both qualitative and quantitative methods was used. Software applications tools called Origin8 WaterGEMSv8i and excel were used to analyze the data obtained from different source. The analysis shows that the current total domestic water demand in town was higher than supply, the water supply coverage was evaluated based level of connection per family and average per capita domestic water consumption was 14.11 l/c/day. Hence, this result indicates there is a gap between demand and supply in the year 2020. The average water loss in Town was 31%, showing that needs a matter of concern. None of the junctions had pressure bigger than 70 m. 65.21% of the junction water column recorded a pressure less than 15m water column due to high elevation. 34.79% of the Town has pressure within the optimum range of 15- 70 m water column and the highest or lowest velocity recorded was zero during steady state analysis. Velocity in some pipe parts was below 0.6 m/s during steady period simulation. Generally the result of the analysis shows that the overall hydraulic performance of the water distribution system of the Town was poor, which is reflected by low water production rate, low water consumption, and high level of non-revenue water, low service coverage, not pressure in permissible range. Therefore, it is significant to rehabilitate and improve the water distribution system capacities, establishing pressure zone, increase pumping rate and drilling additional borehole. In addition provision of more attention to water losses reduction policies and strategies are vital for remedial measures