http://ir.bdu.edu.et/handle/123456789/14130 2026-10-13T02:37:47Z 2026-10-13T02:37:47Z Abebe, Melese http://ir.bdu.edu.et/handle/123456789/17191 2026-09-01T07:30:37Z 2024-06-01T00:00:00Z

Numerical Groundwater Flow Modeling of Alawuha River Catchment, Northeast Ethiopia Abebe, Melese Population growth and rapid socioeconomic development forced groundwater to undergo continuous exploration and uncontrolled exploitation. To ensure the sustainability of this resource, understanding the aquifer system through groundwater flow model development is an indispensable undertaking. This study outlines numerical groundwater flow modeling in the Alawuha River catchment located on the northwest margin of the Ethiopian Main Rift. The study addresses conceptual model development, numerical groundwater flow simulation, and steady-state groundwater flow model development. The model used geologic, hydrologic, hydrogeologic, and geospatial datasets to signify the geometry, boundaries, and physical properties. The model domain was discretized into 215 columns and 156 rows using a 200-meter grid spacing. The model design includes GHB, River, Well, Drain, and Recharge Modflow packages. The model calibration involves a trial-and-error approach until RMSE reaches 4.73 m. This model quantifies the groundwater budget and analyzes the subsurface hydrodynamics in the model domain. The model simulated recharge is 99.43 M m 3 /year. Recharge and river flows are the main inflow and outflow of the study area, respectively. Recharge covers 89.2% of the inflow, and river leakage covers 75.7% of the outflow. The general groundwater flow direction in the study area is to the east, with local flow towards streams. Sensitivity analysis was performed for different values of input parameters; as a result, recharge and hydraulic conductivity became the first and second most sensitive parameters, respectively. Scenario analysis, representing increased abstraction and decreased recharge, was simulated. Results indicate that increased pumping by 80% decreases outflow to rivers by 14.19%. Decreased recharge by 80%, produced decreased outflows from springs by 100%, wells by 26%, and rivers by 90.83%. A groundwater flow model of the Alawuha River catchment that accurately predicts the observed groundwater levels was developed, finally providing new insight into the groundwater systems and resources.

2024-06-01T00:00:00Z Hailu, Minuye http://ir.bdu.edu.et/handle/123456789/17190 2026-09-01T07:24:07Z 2025-01-01T00:00:00Z

Groundwater Recharge Estimation Using WetSpass Model and Soil Moisture Balance Method in Jedeb River Catchment, Upper Blue Nile Basin, North west Ethiopia Hailu, Minuye Groundwater recharge estimation is one of the most important duties in groundwater management practices, despite the estimation methods are full of uncertainties that need to be justified by applying multiple methods. Groundwater recharge estimation has been conducted in the Jedeb river catchment, upper Blue Nile Basin, north-west Ethiopia, with a total area of 628 km2. The WetSpass model and the Soil Moisture Balance (SMB) method have been used to estimate the groundwater recharge amount in this catchment. The WetSpass model is a GISbased distributed water balance model used to estimate recharge, surface runoff, and actual evapotranspiration. The SMB method has been used to estimate groundwater recharge as the residual of precipitation minus evapotranspiration, surface runoff, and the addition of changes in soil moisture storage in the form of bookkeeping procedure using an Excel spread sheet. The mean annual groundwater recharge, surface runoff, and actual evapotranspiration estimated using the WetSpass model are 249 mm, 647 mm, and 696 mm, respectively. They represent 16%, 40%, and 44% of mean annual precipitation, respectively. The mean annual groundwater recharge estimated by monthly SMB has been found to be 213 mm, which accounts for 14% of the mean annual precipitation. Additionally, the mean annual groundwater recharge estimated using the daily SMB is 352 mm. This represents 23% of the study area's mean annual precipitation. By comparing the WetSpass output values with the observed values obtained using the SMB method, the WetSpass model has been validated, and a strong correlation (With r of 1, 0.93 and 0.99, and R 2 of 0.99, 0.99 and 0.87 for recharge, runoff and AET, respectively) has been found. The mean annual groundwater recharge is 249mm or (156,372,000 m3/year). The abstraction rate of the Jedeb river catchment from inventory wells is about 17,821,307 m 3 /yr, which represents 11.4% of mean annual recharge, and it can be concluded that the abstraction rate is safe at the regional scale. The findings of this study can be used as a guide for water resource managers and policymakers in planning and implementing groundwater resource development projects in this catchment.

2025-01-01T00:00:00Z Molla, Wubalem http://ir.bdu.edu.et/handle/123456789/17189 2026-09-01T06:51:46Z 2024-07-01T00:00:00Z

Groundwater Potential and Quality Assessment in Sinakoyekalo Watershed Upper Tekeze Basin, Northwestern Ethiopia Molla, Wubalem This research evaluates groundwater potential and quality in (Sinako-Yekalo watershed Tekezie Basin, Ethiopia). The study area is generally characterized by various topographic features. The high land area is covered by Tarmaber Formation and the remaining area consists of Ashangi Formation and Aiba basalt. Insufficient water resources, lack of hydrogeological investigation, and increasing demand for water resources for different purposes are the main problems in the study area. Therefore, this study aims to identify the groundwater potential zone, aquifer system, and suitability of groundwater for drinking and irrigation purposes. Different approaches have been used to quantify hydrometeorological components and estimate the recharge amount in the study area. The annual rainfall of point data from different nearby stations of the area were analyzed by using two methods (Thiessen polygon and Isohetal). The annual recharge in the study area is estimated by using soil water balance (SWB) method considering different meteorological components (areal depth of rainfall, evapotranspiration, temperature, wind speed, sunshine hour, and relative humidity). The groundwater potential zone was delineated from seven thematic layers (rainfall, geology, slope, land use land cover, drainage density, lineament density, and soil) by weighted overlay using the analytical hierarchy process (AHP) tool of the multi-criteria decision analysis (MCDA) technique. The groundwater potential zone map in the study area is categorized into five different zones. These are very low (0.4%), low (5%), moderate (56%), high (36.6%), and very high (2%). The aquifer system in the study area can be categorized into low (0.5-2 l/s), moderate (2-5 l/s), high (5-25 l/s), and very high (>25 l/s) productive aquifers based on wells and springs yield. The water types in the study area includes Ca-HCO 3 IV , Ca-Mg-HCO 3 , NaNO 3 -HCO 3 , Na-Ca-HCO 3 , Ca-Na-HCO 3 , and Ca-Na-Mg-HCO 3 . The water sources from boreholes, rivers, and springs except for 12.5% of water points are suitable for drinking and irrigation purposes.

2024-07-01T00:00:00Z geze, Habib http://ir.bdu.edu.et/handle/123456789/17188 2026-09-01T06:43:25Z 2025-02-01T00:00:00Z

Remote Sensing and Gis Based Groundwater Potential Mapping of Jara River Catchment, North Eastern Ethiopia geze, Habib Water for domestic water supply and irrigation activities for the populations in the study area is highly dependent on groundwater, which sourced from natural springs and drilled wells. Rapidpopulation growth, poor groundwater management and intermittent rainfall escalate the demandand exploration of groundwater continuously. Thus, the main purpose of this study is to delineate groundwater potential zones using an integrated method of AHP, GIS and remote sensing in JaraRiver catchment, middle Awash Basin, Ethiopia. For the sake of this study, eight groundwater potential influencing thematic layers comprisinglithology, geomorphology, lineaments, land use land cover, soil, drainage density, rainfall and topographic wetness index that affect groundwater distribution were considered. These thematiclayers were combined Using ArcGIS's weighted overlay spatial function tool based on theirweights and rates to create the GWP map and the result indicates that the groundwater potential ofthe area divided into three zones as low, moderate and high covering 57.16, 17.95% and 24.90%of the total area of the basin, respectively. High groundwater potential zone found in the centraand central southern margins, whereas the low groundwater potential zones are localized in the western, south western and eastern parts of the study area. An analysis of the GWP map using current water point yields reveals an 83.33 percent agreement, suggesting a high degree of method accuracy and results of this study using AHP-GIS Remotesensing integrated approach for groundwater potential identification gives an acceptable resultTherefore, it is reasonable to draw the conclusion that this result can be applied to the planning of new groundwater-based projects as well as the extension of the basin's current irrigation project.

2025-02-01T00:00:00Z