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  • 1.
    Dargahi, Bijan
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Setegn, Shimelis Gebriye
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Combined 3D Hydrodynamic and Watershed Modelling of Lake Tana, Ethiopia2011Inngår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 398, nr 1-2, s. 44-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

     The growing high demand for lake Tana water portends a disturbing future. The main objective of this paper is to make a contribution to the development of a sustainable use of the water of Lake Tana. A fully three-dimensional hydrodynamic model was combined with a watershed model and together, these models were successfully validated for the year 2006. The flow structure is characterized by large recirculation and secondary flow regions. Secondary flows are induced by hydrodynamic instabilities occurring at the interfaces of layers with a velocity gradient and the interaction with the irregularities of the bed. The weak stratification process in Lake Tana is characterized by a classic summer profile, which is more pronounced during January-February. Mixing processes in the lake are controlled by wind, the mixing energy induced by both river inflows and the lake outlet, and convective mixing due to the negative buoyancy. An alarming fall of the water levels in Lake Tana was found in response to the planned water withdrawal. The long flushing time (19 months) will not allow a fast decay of contaminated materials released into the lake. The flow structure will not be significantly modified by the planned water withdrawal but the flushing time will decrease. The hydrodynamics of Lake Tana resemble a closed system similar to a shallow reservoir with an overflow type outlet. The implication is that the lake is vulnerable to changes in external conditions and sustainable use of the water resource of the lake will require awareness of this vulnerability. The combined watershed and hydrodynamic models would be effective tools to achieve this awareness. It is also necessary to address the impact of climate change on the fate of the lake. These are all difficult challenges that need to be addressed to safeguard the sensitive eco-system of the area.

  • 2.
    Setegn, Shimelis Gebriye
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Calibration and validation of SWAT2005/ArcSWAT in Anjeni gauged watershed, northern highlands of Ethiopia2007Inngår i: Proceedings of the 4th International SWAT Conference, 2007, s. 375-384Konferansepaper (Annet vitenskapelig)
  • 3.
    Setegn, Shimelis Gebriye
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Hydrological and sediment yield modelling in Lake Tana Basin, Blue Nile Ethiopia2008Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Land and water resources degradation are the major problems on the Ethiopian highlands. Poor land use practices and improper management systems have played a significant role in causing high soil erosion rates, sediment transport and loss of agricultural nutrients. So far limited meas-ures have been taken to combat the problems. In this study a physically based watershed model, SWAT2005 was applied to the Northern Highlands of Ethiopia for modelling of the hydrology and sediment yield. The main objective of this study was to test the performance and feasibility of SWAT2005 model to examine the influence of topography, land use, soil and climatic condi-tion on streamflows, soil erosion and sediment yield. The model was calibrated and validated on four tributaries of Lake Tana as well as Anjeni watershed using SUFI-2, GLUE and ParaSol algo-rithms. SWAT and GIS based decision support system (MCE analysis) were also used to identify the most erosion prone areas in the Lake Tana Basin. Streamflows are more sensitive to the hy-drological response unites definition thresholds than subbasin discretization. Prediction of sedi-ment yield is highly sensitive to subbasin size and slope discretization. Baseflow is an important component of the total discharge within the study area that contributes more than the surface runoff. There is a good agreement between the measured and simulated flows and sediment yields with higher values of coefficients of determination and Nash Sutcliffe efficiency. The an-nual average measured sediment yield in Anjeni watershed was 24.6 tonnes/ha. The annual aver-age simulated sediment yield was 27.8 and 29.5 tonnes/ha for calibration and validation periods, respectively. The SWAT model indicated that 18.5 % of the Lake Tana Basin is erosion potential areas. Whereas the MCE result indicated that 25.5 % of the basin are erosion potential areas. The calibrated model can be used for further analysis of the effect of climate and land use change as well as other different management scenarios on streamflows and soil erosion. The result of the study could help different stakeholders to plan and implement appropriate soil and water conser-vation strategies.

  • 4.
    Setegn, Shimelis Gebriye
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Modelling Hydrological and Hydrodynamic Processes in Lake Tana Basin, Ethiopia2010Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Lake Tana Basin is of significant importance to Ethiopia concerning water resources aspects and the ecological balance of the area. The growing high demands in utilizing the high potentials of water resource of the Lake to its maximal limit, pictures a disturbing future for the Lake. The objective of this study was to assess the influence of topography, soil, land use and climatic varia-bility on the hydrological and hydrodynamic processes of the Lake Tana Basin. The physically based SWAT model was successfully calibrated and validated for flow and sediment yield. Se-quential uncertainty fitting (SUFI-2), parameter solution (ParaSol) and generalized likelihood un-certainty estimation (GLUE) calibration and uncertainty analysis methods were compared and used for the set-up of the SWAT model. There is a good agreement between the measured and simulated flows and sediment yields. SWAT and GIS based decision support system that uses multi-criteria evaluation (MCE) was used to identify the most vulnerable areas to soil erosion in the basin. The results indicated that 12 to 30.5% of the watershed is high erosion potential. Pro-jected changes in precipitation and temperature in the basin for two seasons were analyzed using outputs from fifteen global climate models (GCMs). A historical-modification procedure was used to downscale large scale outputs from GCM models to watershed-scale climate data. The results showed significant changes in streamflow and other hydrological parameters in the period between 2045-2100. SWAT was combined with a three dimensional hydrodynamic model, GEMSS to investigate the flow structure, stratification, the flushing time, lake water balance and finally the Lake‘s water level response to planned water removal. We have found an alarming and dramatic fall of the water levels in Lake Tana as response to the planned water withdrawal. The combination of the two models can be used as a decision support tools to better understand and manage land and water resources in watersheds and waterbodies. The study showed that the Lake Tana Basin may experience a negative change in water balance in the forthcoming decades due to climate change as well as over abstraction of water resources.

  • 5.
    Setegn, Shimelis Gebriye
    et al.
    Department of Earth and Environment, Florida International University (FIU), Miami, Florida, United States.
    Chowdary, V.M.
    Mal, B.C.
    Yohannes, F.
    Kono, Y.
    Water Balance Study and Irrigation Strategies for Sustainable Management of a Tropical Ethiopian Lake: A Case Study of Lake Alemaya2011Inngår i: Water resources management, ISSN 0920-4741, E-ISSN 1573-1650, Vol. 25, nr 9, s. 2081-2107Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lake Alemaya in the Ethiopian Highlands has historically provided the surrounding area with water for domestic use, irrigation, and livestock and has served as a local fishery tank. Increasing irrigation and domestic water use, change in the local climate and changes in the surrounding land cover are believed to be the causes of Lake Alemaya's demise. Expansion of major irrigated crops in particular chat (Catha Edulis), potato and vegetables and non-judicious use of irrigation water in the Lake Alemaya watershed led to presumption that irrigation is partly responsible for the withdrawal of large quantity of water from the lake. Thus, water balance study of Lake Alemaya was carried out under presumed scenarios in order to study the possible trends and fluctuations of the lake water level in response to proposed scenarios. Further, it is essential to study the irrigation performance for developing optimal irrigation schedules in the study area to make the best use of available water for long term sustainability of the water resources of Lake Alemaya. It was identified that expansion of the irrigated area in general and chat cultivation in particular in the study area have been the key to sustainable management of lake water, hence its expansion during the past 37 years (1965-2002) was studied through interpretation of satellite data. Subsequently, performance evaluation of the small-scale irrigation practices for major irrigated crops was carried out. Optimal irrigation schedules for different crop seasons were also developed for these irrigated crops using CROPWAT software. It was found that chat area increased from 190 ha in 1996 to nearly 330 ha in 2002. Further, it was observed that 43% surface area of the lake has reduced within a span of 37 years. Overall, maximum irrigation intensity of chat, potato and vegetables is observed during the first irrigation season of the crop calendar. Particularly, in case of chat, irrigation performance indicators such as Relative Water Supply (RWS), Relative Irrigation Supply (RIS), Depleted Fraction (DF) and Overall Consumed Ratio (OCR) values indicated poor performance of irrigation practices. From the analysis, it was found that the application of a fixed irrigation depth and fixed irrigation interval combinations of (25 mm-25 day), (20 mm-20 day), or (20 mm-25 day) are recommended for chat in the study area. Optimal irrigation schedules were decided on the basis of combination of irrigation interval and depth that results in low loss of irrigation water with reasonable yield reduction. Thus, determination of appropriate water management strategy can ensure proper utilization of the available water resources and improve the water application efficiency of the small-scale irrigation practices around Lake Alemaya, Ethiopia.

  • 6.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Texas A & M University, Spatial Science Laboratory.
    Sediment Yield Modelling from Anjeni Gauged Watershed, Ethiopia using SWAT2005 Model2008Inngår i: The Open Hydrology Journal, ISSN 1874-3781Artikkel i tidsskrift (Annet vitenskapelig)
  • 7.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Melesse, Assefa M.
    Modeling of Sediment Yield From Anjeni-Gauged Watershed, Ethiopia Using SWAT Model2010Inngår i: Journal of the American Water Resources Association, ISSN 1093-474X, E-ISSN 1752-1688, Vol. 46, nr 3, s. 514-526Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Soil and Water Assessment Tool (SWAT) was tested for prediction of sediment yield in Anjeni-gauged watershed, Ethiopia. Soil erosion and land degradation is a major problem on the Ethiopian highlands. The objectives of this study were to evaluate the performance and applicability of SWAT model in predicting monthly sediment yield and assess the impacts of subbasin delineation and slope discretization on the prediction of sediment yield. Ten years monthly meteorological, flow and sediment data were used for model calibration and validation. The annual average measured sediment yield was 24.6 tonnes/ha. The annual average simulated sediment yield was 27.8 and 29.5 tones/ha for calibration and validation periods, respectively. The study found that the observed values showed good agreement with the simulated sediment yield with Nash-Sutcliffe efficiency (NSE) = 0.81, percent bias (PBIAS) = 28%, RMSE-observations standard deviation ratio (RSR) = 0.23, and coefficient of determination (R superset of) = 0.86 for calibration and NSE = 0.79, PBIAS = 30%, RSR = 0.29, and R superset of = 0.84 for validation periods. The model can be used for further analysis of different management scenarios that could help different stakeholders to plan and implement appropriate soil and water conservation strategies.

  • 8.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Melesse, A. M.
    Abbaspour, K.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, R.
    Effect of Downscaling Methods on the Assessment of the Impact of Climate Change in Watershed Scale Management Models2009Inngår i: Proceedings of the American Water Resources Association - AWRA 2009: Spring Specialty Conference: Managing Water Resources Development in a Changing Climate/TPS-09-1, 2009Konferansepaper (Fagfellevurdert)
  • 9.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Melesse, A. M.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, R.
    Water Resources Variability as a Result of Changing Climate: A Case Study in the Lake Tana Basin, Blue Nile Ethiopia2009Inngår i: Proceedings of the American Water Resources Association (AWRA) 2009: Spring Specialty Conference: Managing Water Resources Development in a Changing Climate /TPS-09-1, 2009Konferansepaper (Fagfellevurdert)
  • 10.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Rayner, David
    Melesse, Assefa M.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Impact of Changing Climate on Water Resources Variability in the Lake Tana Basin, EthiopiaManuskript (preprint) (Annet vitenskapelig)
  • 11. Setegn, Shimelis Gebriye
    et al.
    Rayner, David
    Melesse, Assefa M.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Raghavan
    Impact of climate change on the hydroclimatology of Lake Tana Basin, Ethiopia2011Inngår i: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 47, s. W04511-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change has the potential to reduce water resource availability in the Nile Basin countries in the forthcoming decades. We investigated the sensitivity of water resources to climate change in the Lake Tana Basin, Ethiopia, using outputs from global climate models (GCMs). First, we compiled projected changes in monthly precipitation and temperature in the basin from 15 GCMs. Although the GCMs uniformly suggest increases in temperature, the rainfall projections are not consistent. Second, we investigated how changes in daily temperature and precipitation might translate into changes in streamflow and other hydrological components. For this, we generated daily climate projections by modifying the historical data sets to represent the changes in the GCM climatologies and calculated hydrological changes using the Soil and Water Assessment Tool (SWAT). The SWAT model itself was calibrated and validated using the flows from four tributaries of Lake Tana. For the Special Report on Emissions Scenarios A2 scenario, four of the nine GCMs investigated showed statistically significant declines in annual streamflow for the 2080-2100 period. We interpret our results to mean that anthropogenic climate changes may indeed alter the water balance in the Lake Tana Basin during the next century but that the direction of change cannot be determined with confidence using the current generation of GCMs.

  • 12.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Texas A & M University, Spatial Science Laboratory.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Hydrological Modelling in the Lake Tana Basin, Ethiopia using SWAT model2008Inngår i: The Open Hydrology Journal, ISSN 1874-3781, Vol. 2, s. 49-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The SWAT2005 model was applied to the Lake Tana Basin for modeling of the hydrological water balance. The main objective of this study was to test the performance and feasibility of the SWAT model for prediction of streamflow in the Lake Tana Basin. The model was calibrated and validated on four tributaries of Lake Tana; Gumera, GilgelAbay, Megech and Ribb rivers using SUFI-2, GLUE and ParaSol algorithms. The sensitivity analysis of the model to subbasin delineation and HRU definition thresholds showed that the flow is more sensitive to the HRU definition thresholds than subbasin discretization effect. SUFI-2 and GLUE gave good result. All sources of uncertainties were captured by bracketing more than 60% of the observed river discharge. Baseflow (40% - 60%) is an important component of the total discharge within the study area that contributes more than the surface runoff. The calibrated model can be used for further analysis of the effect of climate and land use change as well as other different management scenarios on streamflow and soil erosion.

  • 13.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Texas A & M University, Spatial Science Laboratory.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Identification of Erosion Potential Areas in Lake Tana Catchment, Ethiopia2008Konferansepaper (Annet vitenskapelig)
  • 14.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Texas A & M University, Spatial Science Laboratory.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Identification of High Erosion Potential Areas in Lake Tana Watershed, Ethiopia: Using GIS and SWAT Model2008Inngår i: American Water Resources Association Spring Specialty Conference 2008: GIS and Water Resources V, 2008Konferansepaper (Annet vitenskapelig)
  • 15.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Texas A & M University, Spatial Science Laboratory.
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Streamflow Calibration and Validation of SWAT2005/ArcSWAT in Anjeni Gauged Watershed, Northern Highlands of Ethiopia2006Inngår i: Proceedings of the 4th International SWAT Conference, 2006Konferansepaper (Annet vitenskapelig)
  • 16.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Melesse, Assefa M.
    Spatial delineation of soil erosion vulnerability in the Lake Tana Basin, Ethiopia2009Inngår i: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 23, nr 26, s. 3738-3750Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The main objective of this study was to identify the most vulnerable areas to soil erosion in the Lake Tana Basin, Blue Nile, Ethiopia using the Soil and Water Assessment Tool (SWAT), a physically based distributed hydrological model, and a Geographic Information System based decision support system that uses multi-criteria evaluation (NICE). The SWAT model was used to estimate the sediment yield within each sub-basin and identify the most sediment contributing areas in the basin. Using the NICE analysis, an attempt was made to combine a set of factors (land use, soil, slope and river layers) to make a decision according to the stated objective. On the basis of simulated SWAT, sediment yields greater than 30 tons/ha for each of the sub-basin area, 18.4% of the watershed was determined to be high erosion potential area. The NICE results indicated that 12-30.5% of the watershed is high erosion potential area. Both approaches show comparable watershed area with high soil erosion susceptibility. The output of this research can aid policy and decision makers in determining the soil erosion 'hot spots' and the relevant soil and water conservation measures. (C) Copyright 2009 John Wiley & Sons, Ltd.

  • 17.
    Setegn, Shimelis Gebriye
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Srinivasan, Ragahavan
    Melesse, Assefa M
    Dargahi, Bijan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    SWAT model application and prediction uncertainty analysis in the Lake Tana Basin, Ethiopia2010Inngår i: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, nr 3, s. 357-367Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lake Tana Basin is of significant importance to Ethiopia concerning water resources aspects and the ecological balance of the area. Many years of mismanagement, wetland losses due to urban encroachment and population growth, and droughts are causing its rapid deterioration. The main objective of this study was to assess the performance and applicability of the soil water assessment tool (SWAT) model for prediction of streamflow in the Lake Tana Basin, so that the influence of topography, land use, soil and climatic condition on the hydrology of Lake Tana Basin can be well examined. The physically based SWAT model was calibrated and validated for four tributaries of Lake Tana. Sequential uncertainty fitting (SUFI-2), parameter solution (ParaSol) and generalized likelihood uncertainty estimation (GLUE) calibration and uncertainty analysis methods were compared and used for the set-up of the SWAT model. The model evaluation statistics for streamflows prediction shows that there is a good agreement between the measured and simulated flows that was verified by coefficients of determination and Nash Sutcliffe efficiency greater than 0.5. The hydrological water balance analysis of the basin indicated that baseflow is an important component of the total discharge within the study area that contributes more than the surface runoff. More than 60% of losses in the watershed are through evapotranspiration. Copyright (C) 2009 John Wiley & Sons, Ltd.

  • 18. Taddele, Y. D.
    et al.
    Setegn, Shimelis Gebriye
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Vattendragsteknik.
    Berndtsson, R.
    Hydrological Response of Gilgel Abay River Flow to Climate Change, Lake Tana Basin, Ethiopia2009Inngår i: Proceedings of the 5th International SWAT Conference, 2009Konferansepaper (Fagfellevurdert)
  • 19.
    Tessema, Selome
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Miljöbedömning och -förvaltning.
    Setegn, Shimelis
    Florida International University.
    Mörtberg, Ulla
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik, Miljöbedömning och -förvaltning.
    Analysis of two retention parameter estimation methods for curve number methodology on stream flow prediction2011Inngår i: Ecosystem services in soil and water researchFocus on Soils and Water Symposium: Programme and Abstracts / [ed] Maria Kahlert & Annemieke Gärdenäs, 2011, s. 56-56Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The balance between water use for hydropower and irrigation, sustaining ecosystem services and preventing flood risk is essential to consider in water management for sustainable use. One rising concern is the conflict between the environment and agriculture mainly in lowland areas, where total base flows are abstracted for irrigation without compromising ecological conservation. Hence, it is important to understand the water balance and quantify the dominant components in a watershed to allocate water for all purposes.

    Soil and Water Assessment Tool (SWAT) model was used to understand the hydrological process of the Upper Awash River Basin with the emphasis on analyzing surface runoff generation using the Soil Conservation Service (SCS) curve number method. SWAT incorporates two methods for estimating the retention parameter (S) for SCS curve number method; allowing S to vary with soil profile moisture content (SM) and to let S vary with accumulated plant evapotranspiration (PT). The PT method being more dependent on forcing data than soil data provides another dimension of applicability for data limited watersheds. The results were analyzed by visual comparison of the observed and simulated hydrographs and model performance measures. The hydrographs comparison indicated that the PT method was better in peak flow prediction while SM method outperformed in simulating the low flows. The performance measures (Nash-Sutcliffe Efficiency, Coefficient of Determination and Percent Bias) indicate better prediction by PT method. While the methods agree on predicting the hydrographs, they contradict in the annual water balance assessments. After evapotranspiration, base flow is the dominant component in SM method whereas surface runoff is the foremost in PT method. The results from the PT method agree with the outcome discussed in previous study. Furthermore, it has the advantage of governing by a single parameter that could be calibrated separately to control the base flow and surface runoff contribution to the total flow.

    The analysis shows that care must be taken in selecting a way for quantifying, especially for ungauged catchments where validation of model result is unattainable.

1 - 19 of 19
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