http://ir.bdu.edu.et/handle/123456789/10236 2001-01-13T05:52:59Z 2001-01-13T05:52:59Z Getachew, Genanew http://ir.bdu.edu.et/handle/123456789/16055 2024-10-21T08:22:33Z 2024-02-01T00:00:00Z

Estimating the Water Footprint of the Selected Crops on the Beles Sub-Basin of Blue Nile Ethiopia Getachew, Genanew The aim of this study was to estimate the water footprint of selected crops in the Beles sub-basin. To accomplish this, relevant data on the chosen crops, including crop yield, area coverage, and meteorological data, were collected and analyzed. The CROPWAT model version 8.0 was employed to calculate parameters like crop water requirement, effective rainfall, and irrigation need. The CROPWAT data outputs, including effective rainfall and irrigation requirements, were inputted into Microsoft Excel to compute the green water footprint (GWF) and blue water footprint (BWF) of the selected crops. The specific objectives were to determine the GWF and BWF for the chosen crops in the study area, as well as to quantify the total yearly water volume utilized by the crops through irrigation during the growing seasons. The findings revealed discrepancies in irrigation water needs among the selected crops. For example, during the rainy season, maize crops in the Pawi area required 428.3 mm of rainwater, whereas in the Dangila area, the rainwater requirement was 404 mm. However, during the irrigated season, maize crops in Pawi had an irrigation water requirement of 579.4 mm, while in Dangila it was 570.3 mm. additionally; the water footprint of each crop was assessed. Maize crops exhibited a higher GWF during the rainy season in Pawi (818.4 m3/ton) compared to Dangila (508 m3/ton). In the irrigated season, maize crops in Pawi had a higher BWF (506.7 m3/ton) than Dangila (348.7 m3/ton). However, the maize water footprint in Dangila indicated a higher GWF (13.7 m3/ton) compared to Pawi (4.9 m3/ton). In terms of onion cultivation during the irrigated season, Dangila showed a higher BWF (416 m3/ton) than Pawi (154.8 m3/ton), with Dangila also exhibiting a higher GWF (15.9 m3/ton) compared to Pawi (1.4 m3/ton). For soybean cultivation during the rainy season in Pawi, the water footprint was determined to be 1011.1m³/ton. This study is significant for policymakers, farmers, water management authorities, and researchers as it offers insights to implement water-saving practices and enhance efficient water resource management in the study area. Therefore, this study plays a crucial role in addressing and alleviating water scarcity, especially in relation to crop cultivation. Key words: Blue Water Footprint, Green Water Footprint, Beles Sub Basin and Crop Yield, Water Use.

2024-02-01T00:00:00Z BANCH, TAREKE YIMER http://ir.bdu.edu.et/handle/123456789/16054 2024-10-21T08:21:08Z 2024-03-01T00:00:00Z

ASSESSMENT OF SURFACE IRRIGATION POTENTIAL OF MILLE WATERSHED IN AWASH BASIN USING AHP-GIS AND SWAT MODEL BANCH, TAREKE YIMER Assessment of irrigation potential is essential for the development of irrigation schemes for addressing food security problems. This study focused on assessing surface irrigation potential of Mille watershed in Awash basin Ethiopia. This was done by using GIS-based Analytical Hierarchy Process (AHP-GIS) techniques, a Hydrological Soil and Water Assessment Tools (SWAT) model and a FAO CROPWAT 8.0 model. AHP-GIS was used to identify suitable land for surface irrigation, the SWAT model was used for stream flow simulation and CROPWAT model was used to estimate crop irrigation water requirement for selected dominant crops within the watershed. The gross irrigation requirement was calculated for three seletcted crops (wheat, sorghum and maize) and compared with the available flow to get irrigation potential for surface irrigation. The overlay results of various factors using the AHP-GIS technique under a 85% threshold level gave 91,800 ha of the watershed as a suitable area for surface irrigation. The results of model performance indicators for calibration and validation were in the acceptable range (R2=0.88, NSE=0.87 & PBIAS 0.5) and (R2=0.85, NSE=0.83 & PBIAS=-0.7) respectively. The annual average simulated stream flow was estimated as 17.3 m3/s and the water demand required by the whole selected crops was 57.2 m3/s. Finally, the total suitable irrigation potential of the study watershed was 25,783 ha, which can be irrigated with the available flow of 17.2 m3/s. In general, this study indicated that the surface irrigation potential of the Mille River watershed was limited by the simulated stream flow of the watershed in that the water demand of the crops was much greater than the simulated minimum flow of the rivers in major sub-watersheds. Therefore, to increase the irrigation potential of the River sub-watershed other irrigation methods can be used and construct a water harvesting structure. Keywords: Land suitability, Analytical Hierarchy Process, Mille watershed, SWAT model, CROPWAT Model, Calibration,Validation.

2024-03-01T00:00:00Z ASHETU, AMEYU BASHA http://ir.bdu.edu.et/handle/123456789/15340 2023-06-06T12:42:53Z 2021-01-01T00:00:00Z

COMPARISON OF SEEPAGE ANALYSES USING COMPUTER BASED NUMERICAL METHOD AND GRAPHICAL SOLUTIONS: THE CASE STUDY OF MEGECH DAM ASHETU, AMEYU BASHA Embankment dams are mainly constructed of earth and rock-fill materials. This study is aimed at comparative analysis of seepage using computer based numerical method and graphical method considering Megech earth-rock fill dam as a case. Geo-studio 2012 model (SEEP/W Module) was employed to conduct the seepage analysis of the dam from the numerical approach. The Numerical seepage analysis was estimate by using a finite element approach (SEEP/W), while the graphical method is solely based on the construction of flow nets. Using flow net method of seepage analysis at normal water level, the seepage was 2.2x10 -5 m 3 /second the result at maximum water level was 2.3x10 -5 m 3 /sec. It looks that for the maximum water level are more excessive seepage than at normal water level. The result of the SEEP/W module of the Geo studio 12 model shows that the total flow per unit length through the dam body and foundation at full reservoir condition is 2.0056x10 -5 m 3 /sec, and for maximum water level, the result was 2.752x10 -5 m 3 /sec. The result indicates that the graphical method underestimates seepage magnitude for the maximum water level case, whereas for the normal water level case, it overestimates the seepage magnitude. However, the results are still closer to each other despite the many uncertainties and simplified assumptions involved under the graphical approach. This study is therefore a good illustration of the fact that sometimes more complex approaches may not necessarily give more accurate results than the simpler approaches. Keywords: phreatic line, flow net, Seep/W, Normal water level, and Maximum water level

2021-01-01T00:00:00Z ANLEY, LIYEW http://ir.bdu.edu.et/handle/123456789/15339 2023-06-06T12:41:10Z 2023-03-01T00:00:00Z

EVALUETING THE WATER BALANCE COMPONENTS BY INTEGRATING SATELLITE AND GROUND BASED OBSERVATION DATA IN THE ABBAY BASIN, ETHIOPIA ANLEY, LIYEW As the world metrological organization reported African countries have uneven topography and insufficient metrological information. For this reason, retrieving satellite-based rainfall products has been crucial and it is used as a substitute for ground sources of rainfall estimation. The main aim of this research is to evaluating and compare major water balance components by retrieving satellite products and show as an alternative for ground-based observation data. Both continuous and categorical statistical performance were employed in the comparison to compare with the satellite products and ground-based observation at each aerial weighted station. Throughout the period of (2002–2018), all satellite rainfall products with varying spatial resolutions were convert into equivalent spatial resolution and then both point-to-pixel weighted aerial method were used. Every station created a Thiessen polygon. Comparison evapotranspiration perform based on it obtained from both water balance equation and MODIS product. Since both precipitation product and run off validate by ground before the remain component evaporation used for validate against satellite-based evapotranspiration. With correlation coefficients (r) for Climate Hazards Group Infra-Red Precipitation with Station (CHIRPS, Precipitation Estimation from remotely sensed information using Artificial Neural Network Climate Data Record (PERSIANN -CDR), European Reanalysis Agriculture fifth generation (ERA AG _5) and European Reanalysis fifth generation (ERA _5) of (0.91, 0.87, 0.80, and 0.78), respectively, Northeast of upper Abbay Basin (NEUAB) were a good agreement. Furthermore, chirps have Probability of Detection (POD), False Alarm Rate (FAR) and Critical success Indices (CSI) scores of 0.9, 0.46, and 0.86, respectively. Thus, research summarized as seventeen years long term mean of Water Balance Components (WBC) in the Abbay basin precipitation, evapotranspiration, Run off and Terrestrial water storage (TWS) from Gravity Recovery and climate experiment (GRACE) 1936,696, 529, and 36 mm respectively. MOD16A2 evapotranspiration products can show good performance in each sub basins. This research recommends that propagating errors across each component in the water budget equation, it was possible to estimate the relative uncertainty of evapotranspiration. Keywords: Satellite Product, Water Balance Component, GRACE

2023-03-01T00:00:00Z