Water Resource

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

Browse

Subject: search.filters.subject.Remote Sensing

Search Results

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    GROUNDWATER POTENTIAL ASSESSMENT USING GIS AND REMOTE SENSING: A CASE STUDY IN MANTHA WATERSHED, OMO-GIBE RIVER BASIN, ETHIOPIA
    (Hawassa University, 2023-05-27) ZERIHUN ZENEBE JEBULA
    In the current study area, the demand for groundwater is increasing. Therefore, the ultimate purpose of this study was to map groundwater potential zones in Mantha watershed using geographic information system and remote sensing. Ten groundwater controlling factors (geology, rainfall, lineament, soil, land use/land cover, geomorphology, slope, and distance to river, elevation, and drainage density) were used to map the groundwater potential zones of the study watershed using remote sensing data. Among these, three layers (geology, geomorphology, and soil) of the study watershed were extracted from existing data, and five layers (slope, drainage density, elevation, lineament, and distance to river) were developed using DEM of 30m*30m spatial resolution. 20 years precipitation data obtained from National meteorology Agency of Ethiopia were converted into areal rainfall using inverse distance weight interpolation method integrated with ArcGIS 10.8 to develop rainfall layer of the study watershed. Landsat8 of the year 2020 was used to map the land use/land cover of the study watershed using supervised image classification with maximum likelihood algorism in ERDAS 2015. Then, all thematic layers were reclassified using literatures and Jenks methods and finally rated in analytical hierarchy process. The results of ten thematic layers data rated in in analytical hierarchy process indicated that the most dominant thematic layers that hold high weight relative to others were- geology (28%), rainfall (16.6%), lineament density (12.9%), and soil (10.3%). Groundwater potential map of the study watershed was obtained by using weights derived from AHP and overlay analysis conducted in arc GIS10.8_ platform. There were four groundwater potential zones mapped in the Mantha watershed, namely, very high, high, moderate, and low. The map result was verified by well data and the result showed strong agreement in each category with 85.7%, 83.33%, 90%, and 100% respectively. The finding of this study indicates that the geographic information system and remote sensing model approach are reliable and can be a reliable prospecting method of groundwater potential zone
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    SPATIAL AND TEMPORAL ANALYSIS OF EVAPOTRANSPIRATION USING SEBAL MODEL IN THE DATA SCARCE MOJO CATCHMENT, ETHIOPIA
    (Hawassa University, 2024-07-10) HIRUT GIRMA
    Evapotranspiration is essential to the hydrological and energy cycles, as well as to the estimation of irrigation needs and water supplies. For improved water resource planning and management, accurate ET estimation is crucial to the measurement of the water balance at the basin, river basin, and regional scales. Remotely sensed data are good alternatives that support the collection of climate data. The objective of this study was to estimate Spatial and temporal analysis of evapotranspiration using surface energy balance algorithm for the land (SEBAL) model in the data scarce Mojo catchment. This study used the SEBAL model to assess satellite evapotranspiration from October to March 2022. For this analysis, net radiation, soil heat flow, sensible heat flux, latent heat flux, surface emissivity, surface temperature, surface radiance, surface reflectance, surface albedo, NDVI, and LAI are calculated. The sensible heat flux is calculated by determining the hot and cold pixels under consideration via the atmospheric stability conditions. Finally, evapotranspiration maps are plotted. Consequently, GRASS GIS software and SEBAL Python were used to determine the daily, monthly, and seasonal evapotranspiration in the research area. The findings demonstrated a good degree of agreement between the evapotranspiration values provided by SEBAL and the FAO Penman-Monteith method, with the latter reporting the lowest error (RMSE = 1.14) and the highest correlation (R2 = 0.96). The estimated ET values for the months of March through October, In March and November, the highest and lowest calculated AET values were 6.43 and 4.2 mm/d, respectively. ET values were computed for emperical methods using REF-ET software. In order to compare the results obtained from the SEBAL approach, the Standard Penman-Monteith value for the weather station was utilized as a reference. The results indicate that, given the SEBAL algorithm's acceptable performance in estimating actual evapotranspiration using Landsat 8 satellite images, it could be a very practical method and play a crucial role in understanding water resource management on various earthly surfaces, which is necessary to achieve sustainable development of water resources in the basin. It is also advised that the SEBAL algorithm be applied in the upper Awash basin's remaining catchment
  • No Thumbnail Available
    Item
    IMPACT OF LAND USE/LAND COVER CHANGE ON CATCHEMENT HYDROLOGY: THE CASE OF GIDABO CATCHEMENT, RIFT VALLEY LAKES BASIN, ETHIOPIA
    (Hawassa University, 2021-03-18) TESHOME MEKONNEN KAYESSO
    The study analyzed the land use/land cover change between the 1996, and 2016, and the effect these changes had on Hydrology on Gidabo catchment. Within 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 Gidabo catchment. Land use maps of 1996, 2006 and 2016 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 three land use maps (1996, 2006 & 2016). 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 %. 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