Water Resource

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

Browse

End date: 2021Has files: Yes

Search Results

Now showing 1 - 10 of 102
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    IMPACT OF CLIMATE CHANGE ON LOCAL HYDROLOGY: A CASE STUDY IN AGULA’E WATERSHED, TEKEZE BASIN, NORTH ETHIOPIA
    (Hawassa University, 2017-10-16) TSEGAY AREGAWI ATSBAHA
    Climate change, nowadays, has significant impact on the water resource system of an area. This study was conducted in Agula’e watershed, Tekeze river basin, Ethiopia, using Water and Energy Transfer through Soil, Plants and Atmosphere (WetSpa) hydrological model and General Circulation Model (GCM) aiming at estimating the impact of climate change on water availability of the study area. By making proper calibration, precipitation and temperature outputs of HadCM3 coupled atmosphere-ocean GCM model for A2a (medium to high) and B2a (Medium to low) SRES emission scenarios were downscaled using Statistical Downscaling Model (SDSM). In 2020s, precipitation, maximum temperature, minimum temperature and potential evapotranspiration will increase by 1.03%, 0.55%, 0.09% and 2.08% for A2a emission scenario and 1.84%, 0.42%, 0.1% and 2.14% for B2a emission scenario respectively. In 2050s, it will be expected an increment trend in precipitation, maximum temperature, minimum temperature and potential evapotranspiration by 0.8%, 1.63%, 0.12% and 3.13% for A2a emission scenario and 3.06%, 1.19%, 0.10% and 2.95% for B2a emission scenario. In 2080s, precipitation, maximum temperature, minimum temperature and potential evapotranspiration will increase by 1.05%, 3.17%, 0.15% and 4.63% % for A2a emission scenario and 1.35%, 1.97%, 0.13% and 3.65% for B2a emission scenario. In the future period, the overall trend in aerial mean maximum temperature, precipitation, and potential evapotranspiration show positive increment by 2.5%, 0.96%, and 3.28% under A2a and 2.05%, 2.12% and 2.91% for B2a emission scenario respectively. Minimum temperature will not show significance change for both emission scenarios. The model showed that precipitation and actual evapotranspiration results in average increment trend by 1.03%, 0.78% and 1.03% for A2a scenario and 1.93%, 3.05% 1.34% for B2a scenario in 2020s, 2050s and 2080s time horizons respectively. In the future time horizons, actual evapotranspiration will be increased by 6.96%, 7.01% and 7.42% under A2a scenario and by 8.49%, 9.91% and 8.25% for the B2a scenario. The overall trend of precipitation and actual evapotranspiration value will increase by 0.95% and 7.13% under A2a emission scenario and 2.11% and 8.88% under B2a emission scenario respectively. Surface runoff will generally has decrement trend in all the future periods and will averagely decrease by 71% for A2a and70% for B2a emission scenarios
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    IMPACT OF LAND USE/LAND COVER DYNAMIC ON HYDROLOGY REGIME: A CASE STUDY IN THE UPPER BARO BASIN, GAMBELLA, SOUTHWEST ETHIOPIA
    (Hawassa University, 2019-03-11) Tewodros getu engida
    The principal driving forces for land use/land cover change(LULCC) are rapid increases of population and forest clearing. Those are important factors that influence the hydrological condition of a catchment. Land use/land cover change can also result in change of flood frequency, increase peak flows, base flow, and annual mean discharge. To reverses such kind of problems, assessment of hydrological condition in relation to LULC and finding solution at a watershed level is necessary. The objective of this study was to assess the impacts of LULC change on the hydrology of Upper Baro Basin using Soil and Water Assessment Tool model. The LULC change analysis was performed by using supervised classification method using ERDAS imagine 2014. The accuracy of the classified maps was assessed using error matrix of each selected period. Consequently, 92.14%, 94.63% and 95.63% were found for LULC classification of 1987 ,2002 and 2017 study years, respectively. The result show that there was a drastic decreased of grass land by15.64 % and an increase of agricultural land and settlement by 18.01% and 13.01%, respectively over period. SWAT model was adopted to perform simulation of the main hydrological component in order to finding the effect of LULCC using in 1987,2002 and 2017 and also calibration, validation and uncertainty analysis were performed using sequential uncertainty fitting (SUFI-2). The result showed that there was a reasonable agreement between observed and simulated streamflow with coefficient of determination (R2) and Nash-Sutcliffe efficiency values 0.87 and 0.76 for calibration periods 1990-2002 and 0.77and 0.72 for validation period of 2003 to 2010 respectively. Further, the model was predicting the impact of LULC change on streamflow for period 1987,2002 and 2017. Evaluation of hydrologic response unit (HRU) due to LULCC showed that mean monthly streamflow was increased by 35.8% in wet months and decreased by 21.05% in dry months between the years 1987 and 2002. While betwee 2002 and 2017, it was increased by 47.1% and 3.49% for wet and dry months, and the year 2017 and 1987, it was increased by 82.9% and 15.54% for wet and dry months respectively. InVEST model was used to assess the total soil loss potential for each LULCC, these result show that increased from 276462.8 in 1987 to 391741.2 ton/year in 2017 and the mean annual soil loss was also increased from 67.67ton/ha/year in 1987 to 70.84ton/ha/year in 2017. The trend of soil loss and sediment export indicates that an increase in LULCC. Deforestation and soil erosion problems need to be give attention urgently to maintain the stability and resilience of the ecosystem
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    ASSESSMENT OF RURAL COMMUNITY WATER SUPPLY SCHEMES SUSTAINABILITY AT SHEBEDINO WOREDA, SIDAMA ZONE, SNNPR, ETHIOPIA
    (Hawassa University, 2018-10-27) WONDWOSEN ADMASU
    In developing country there is a problem of water supply schemes sustainability due to damage of functional water supply schemes with different reasons through their service period. This situation is also observed in Ethiopia with in all states and woredas. Shebedino woreda found in sidama zone, SNNPR State has a visible problem in this regard. This study was conducted to assess the sustainability of water supply schemes in Shebedino woreda(study area). The assessment was focused on the functionality of water supply schemes; examining the sustainability of water supply schemes through technical, financial, organizational, social, environmental factors, and community perception within four sampled kebele and 15 water supply schemes of the study area. For this research purpose primary and secondary data were used. Data was collected focused on House to House interview, Field observation, Focus Group Discussion and Key Informant interview with organized questions. Field observation was conducted .The data was analyzed by descriptive analysis method. From finding the nonfunctional water supply scheme of study area was 33.58 % which is greater than from SNNPR and national level. Technical, financial, organizational, social, environmental factors and community perception have major contribution in the sustainability of water supply schemes. Among the reasons for frequently failed of water supply schemes, lack of spare part has taken the large percentage which is 47.78% and the second large proportion is poor management which is 31.67%. Inadequate budget were contributed for insecurity of sustainability of water supply schemes .The study result shows that more emphasis is not given for community participation in planning and technological selection. Large percentage of finance was allocated for newly constructed water supply schemes by NGOs 79.2%, but government and community have low contribution. Community participation, technical factors and organizational management are the major parts need more emphasis to ensure the sustainability of water supply schemes. It was found that even though the community has high willingness in contribution for the sustainability of water supply schemes, but there is low practice of community involvement. This positive attitude has significance in the sustainability of water supply schemes but need more improvement